--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/os/linux/os_linux.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,5999 @@
+/*
+ * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+// no precompiled headers
+#include "classfile/classLoader.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "code/icBuffer.hpp"
+#include "code/vtableStubs.hpp"
+#include "compiler/compileBroker.hpp"
+#include "compiler/disassembler.hpp"
+#include "interpreter/interpreter.hpp"
+#include "jvm_linux.h"
+#include "logging/log.hpp"
+#include "memory/allocation.inline.hpp"
+#include "memory/filemap.hpp"
+#include "oops/oop.inline.hpp"
+#include "os_linux.inline.hpp"
+#include "os_share_linux.hpp"
+#include "prims/jniFastGetField.hpp"
+#include "prims/jvm.h"
+#include "prims/jvm_misc.hpp"
+#include "runtime/arguments.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/extendedPC.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/init.hpp"
+#include "runtime/java.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/objectMonitor.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "runtime/osThread.hpp"
+#include "runtime/perfMemory.hpp"
+#include "runtime/sharedRuntime.hpp"
+#include "runtime/statSampler.hpp"
+#include "runtime/stubRoutines.hpp"
+#include "runtime/thread.inline.hpp"
+#include "runtime/threadCritical.hpp"
+#include "runtime/timer.hpp"
+#include "semaphore_posix.hpp"
+#include "services/attachListener.hpp"
+#include "services/memTracker.hpp"
+#include "services/runtimeService.hpp"
+#include "utilities/align.hpp"
+#include "utilities/decoder.hpp"
+#include "utilities/defaultStream.hpp"
+#include "utilities/events.hpp"
+#include "utilities/elfFile.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/vmError.hpp"
+
+// put OS-includes here
+# include <sys/types.h>
+# include <sys/mman.h>
+# include <sys/stat.h>
+# include <sys/select.h>
+# include <pthread.h>
+# include <signal.h>
+# include <errno.h>
+# include <dlfcn.h>
+# include <stdio.h>
+# include <unistd.h>
+# include <sys/resource.h>
+# include <pthread.h>
+# include <sys/stat.h>
+# include <sys/time.h>
+# include <sys/times.h>
+# include <sys/utsname.h>
+# include <sys/socket.h>
+# include <sys/wait.h>
+# include <pwd.h>
+# include <poll.h>
+# include <semaphore.h>
+# include <fcntl.h>
+# include <string.h>
+# include <syscall.h>
+# include <sys/sysinfo.h>
+# include <gnu/libc-version.h>
+# include <sys/ipc.h>
+# include <sys/shm.h>
+# include <link.h>
+# include <stdint.h>
+# include <inttypes.h>
+# include <sys/ioctl.h>
+
+#ifndef _GNU_SOURCE
+ #define _GNU_SOURCE
+ #include <sched.h>
+ #undef _GNU_SOURCE
+#else
+ #include <sched.h>
+#endif
+
+// if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling
+// getrusage() is prepared to handle the associated failure.
+#ifndef RUSAGE_THREAD
+ #define RUSAGE_THREAD (1) /* only the calling thread */
+#endif
+
+#define MAX_PATH (2 * K)
+
+#define MAX_SECS 100000000
+
+// for timer info max values which include all bits
+#define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
+
+#define LARGEPAGES_BIT (1 << 6)
+////////////////////////////////////////////////////////////////////////////////
+// global variables
+julong os::Linux::_physical_memory = 0;
+
+address os::Linux::_initial_thread_stack_bottom = NULL;
+uintptr_t os::Linux::_initial_thread_stack_size = 0;
+
+int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL;
+int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
+int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL;
+Mutex* os::Linux::_createThread_lock = NULL;
+pthread_t os::Linux::_main_thread;
+int os::Linux::_page_size = -1;
+bool os::Linux::_supports_fast_thread_cpu_time = false;
+uint32_t os::Linux::_os_version = 0;
+const char * os::Linux::_glibc_version = NULL;
+const char * os::Linux::_libpthread_version = NULL;
+
+static jlong initial_time_count=0;
+
+static int clock_tics_per_sec = 100;
+
+// For diagnostics to print a message once. see run_periodic_checks
+static sigset_t check_signal_done;
+static bool check_signals = true;
+
+// Signal number used to suspend/resume a thread
+
+// do not use any signal number less than SIGSEGV, see 4355769
+static int SR_signum = SIGUSR2;
+sigset_t SR_sigset;
+
+// utility functions
+
+static int SR_initialize();
+
+julong os::available_memory() {
+ return Linux::available_memory();
+}
+
+julong os::Linux::available_memory() {
+ // values in struct sysinfo are "unsigned long"
+ struct sysinfo si;
+ sysinfo(&si);
+
+ return (julong)si.freeram * si.mem_unit;
+}
+
+julong os::physical_memory() {
+ return Linux::physical_memory();
+}
+
+// Return true if user is running as root.
+
+bool os::have_special_privileges() {
+ static bool init = false;
+ static bool privileges = false;
+ if (!init) {
+ privileges = (getuid() != geteuid()) || (getgid() != getegid());
+ init = true;
+ }
+ return privileges;
+}
+
+
+#ifndef SYS_gettid
+// i386: 224, ia64: 1105, amd64: 186, sparc 143
+ #ifdef __ia64__
+ #define SYS_gettid 1105
+ #else
+ #ifdef __i386__
+ #define SYS_gettid 224
+ #else
+ #ifdef __amd64__
+ #define SYS_gettid 186
+ #else
+ #ifdef __sparc__
+ #define SYS_gettid 143
+ #else
+ #error define gettid for the arch
+ #endif
+ #endif
+ #endif
+ #endif
+#endif
+
+
+// pid_t gettid()
+//
+// Returns the kernel thread id of the currently running thread. Kernel
+// thread id is used to access /proc.
+pid_t os::Linux::gettid() {
+ int rslt = syscall(SYS_gettid);
+ assert(rslt != -1, "must be."); // old linuxthreads implementation?
+ return (pid_t)rslt;
+}
+
+// Most versions of linux have a bug where the number of processors are
+// determined by looking at the /proc file system. In a chroot environment,
+// the system call returns 1. This causes the VM to act as if it is
+// a single processor and elide locking (see is_MP() call).
+static bool unsafe_chroot_detected = false;
+static const char *unstable_chroot_error = "/proc file system not found.\n"
+ "Java may be unstable running multithreaded in a chroot "
+ "environment on Linux when /proc filesystem is not mounted.";
+
+void os::Linux::initialize_system_info() {
+ set_processor_count(sysconf(_SC_NPROCESSORS_CONF));
+ if (processor_count() == 1) {
+ pid_t pid = os::Linux::gettid();
+ char fname[32];
+ jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
+ FILE *fp = fopen(fname, "r");
+ if (fp == NULL) {
+ unsafe_chroot_detected = true;
+ } else {
+ fclose(fp);
+ }
+ }
+ _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
+ assert(processor_count() > 0, "linux error");
+}
+
+void os::init_system_properties_values() {
+ // The next steps are taken in the product version:
+ //
+ // Obtain the JAVA_HOME value from the location of libjvm.so.
+ // This library should be located at:
+ // <JAVA_HOME>/lib/{client|server}/libjvm.so.
+ //
+ // If "/jre/lib/" appears at the right place in the path, then we
+ // assume libjvm.so is installed in a JDK and we use this path.
+ //
+ // Otherwise exit with message: "Could not create the Java virtual machine."
+ //
+ // The following extra steps are taken in the debugging version:
+ //
+ // If "/jre/lib/" does NOT appear at the right place in the path
+ // instead of exit check for $JAVA_HOME environment variable.
+ //
+ // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
+ // then we append a fake suffix "hotspot/libjvm.so" to this path so
+ // it looks like libjvm.so is installed there
+ // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
+ //
+ // Otherwise exit.
+ //
+ // Important note: if the location of libjvm.so changes this
+ // code needs to be changed accordingly.
+
+ // See ld(1):
+ // The linker uses the following search paths to locate required
+ // shared libraries:
+ // 1: ...
+ // ...
+ // 7: The default directories, normally /lib and /usr/lib.
+#if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390)
+ #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib"
+#else
+ #define DEFAULT_LIBPATH "/lib:/usr/lib"
+#endif
+
+// Base path of extensions installed on the system.
+#define SYS_EXT_DIR "/usr/java/packages"
+#define EXTENSIONS_DIR "/lib/ext"
+
+ // Buffer that fits several sprintfs.
+ // Note that the space for the colon and the trailing null are provided
+ // by the nulls included by the sizeof operator.
+ const size_t bufsize =
+ MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
+ (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
+ char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
+
+ // sysclasspath, java_home, dll_dir
+ {
+ char *pslash;
+ os::jvm_path(buf, bufsize);
+
+ // Found the full path to libjvm.so.
+ // Now cut the path to <java_home>/jre if we can.
+ pslash = strrchr(buf, '/');
+ if (pslash != NULL) {
+ *pslash = '\0'; // Get rid of /libjvm.so.
+ }
+ pslash = strrchr(buf, '/');
+ if (pslash != NULL) {
+ *pslash = '\0'; // Get rid of /{client|server|hotspot}.
+ }
+ Arguments::set_dll_dir(buf);
+
+ if (pslash != NULL) {
+ pslash = strrchr(buf, '/');
+ if (pslash != NULL) {
+ *pslash = '\0'; // Get rid of /lib.
+ }
+ }
+ Arguments::set_java_home(buf);
+ set_boot_path('/', ':');
+ }
+
+ // Where to look for native libraries.
+ //
+ // Note: Due to a legacy implementation, most of the library path
+ // is set in the launcher. This was to accomodate linking restrictions
+ // on legacy Linux implementations (which are no longer supported).
+ // Eventually, all the library path setting will be done here.
+ //
+ // However, to prevent the proliferation of improperly built native
+ // libraries, the new path component /usr/java/packages is added here.
+ // Eventually, all the library path setting will be done here.
+ {
+ // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
+ // should always exist (until the legacy problem cited above is
+ // addressed).
+ const char *v = ::getenv("LD_LIBRARY_PATH");
+ const char *v_colon = ":";
+ if (v == NULL) { v = ""; v_colon = ""; }
+ // That's +1 for the colon and +1 for the trailing '\0'.
+ char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
+ strlen(v) + 1 +
+ sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1,
+ mtInternal);
+ sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon);
+ Arguments::set_library_path(ld_library_path);
+ FREE_C_HEAP_ARRAY(char, ld_library_path);
+ }
+
+ // Extensions directories.
+ sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
+ Arguments::set_ext_dirs(buf);
+
+ FREE_C_HEAP_ARRAY(char, buf);
+
+#undef DEFAULT_LIBPATH
+#undef SYS_EXT_DIR
+#undef EXTENSIONS_DIR
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// breakpoint support
+
+void os::breakpoint() {
+ BREAKPOINT;
+}
+
+extern "C" void breakpoint() {
+ // use debugger to set breakpoint here
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// signal support
+
+debug_only(static bool signal_sets_initialized = false);
+static sigset_t unblocked_sigs, vm_sigs;
+
+bool os::Linux::is_sig_ignored(int sig) {
+ struct sigaction oact;
+ sigaction(sig, (struct sigaction*)NULL, &oact);
+ void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
+ : CAST_FROM_FN_PTR(void*, oact.sa_handler);
+ if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+void os::Linux::signal_sets_init() {
+ // Should also have an assertion stating we are still single-threaded.
+ assert(!signal_sets_initialized, "Already initialized");
+ // Fill in signals that are necessarily unblocked for all threads in
+ // the VM. Currently, we unblock the following signals:
+ // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
+ // by -Xrs (=ReduceSignalUsage));
+ // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
+ // other threads. The "ReduceSignalUsage" boolean tells us not to alter
+ // the dispositions or masks wrt these signals.
+ // Programs embedding the VM that want to use the above signals for their
+ // own purposes must, at this time, use the "-Xrs" option to prevent
+ // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
+ // (See bug 4345157, and other related bugs).
+ // In reality, though, unblocking these signals is really a nop, since
+ // these signals are not blocked by default.
+ sigemptyset(&unblocked_sigs);
+ sigaddset(&unblocked_sigs, SIGILL);
+ sigaddset(&unblocked_sigs, SIGSEGV);
+ sigaddset(&unblocked_sigs, SIGBUS);
+ sigaddset(&unblocked_sigs, SIGFPE);
+#if defined(PPC64)
+ sigaddset(&unblocked_sigs, SIGTRAP);
+#endif
+ sigaddset(&unblocked_sigs, SR_signum);
+
+ if (!ReduceSignalUsage) {
+ if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
+ sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
+ }
+ if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
+ sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
+ }
+ if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
+ sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
+ }
+ }
+ // Fill in signals that are blocked by all but the VM thread.
+ sigemptyset(&vm_sigs);
+ if (!ReduceSignalUsage) {
+ sigaddset(&vm_sigs, BREAK_SIGNAL);
+ }
+ debug_only(signal_sets_initialized = true);
+
+}
+
+// These are signals that are unblocked while a thread is running Java.
+// (For some reason, they get blocked by default.)
+sigset_t* os::Linux::unblocked_signals() {
+ assert(signal_sets_initialized, "Not initialized");
+ return &unblocked_sigs;
+}
+
+// These are the signals that are blocked while a (non-VM) thread is
+// running Java. Only the VM thread handles these signals.
+sigset_t* os::Linux::vm_signals() {
+ assert(signal_sets_initialized, "Not initialized");
+ return &vm_sigs;
+}
+
+void os::Linux::hotspot_sigmask(Thread* thread) {
+
+ //Save caller's signal mask before setting VM signal mask
+ sigset_t caller_sigmask;
+ pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
+
+ OSThread* osthread = thread->osthread();
+ osthread->set_caller_sigmask(caller_sigmask);
+
+ pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
+
+ if (!ReduceSignalUsage) {
+ if (thread->is_VM_thread()) {
+ // Only the VM thread handles BREAK_SIGNAL ...
+ pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
+ } else {
+ // ... all other threads block BREAK_SIGNAL
+ pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
+ }
+ }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// detecting pthread library
+
+void os::Linux::libpthread_init() {
+ // Save glibc and pthread version strings.
+#if !defined(_CS_GNU_LIBC_VERSION) || \
+ !defined(_CS_GNU_LIBPTHREAD_VERSION)
+ #error "glibc too old (< 2.3.2)"
+#endif
+
+ size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
+ assert(n > 0, "cannot retrieve glibc version");
+ char *str = (char *)malloc(n, mtInternal);
+ confstr(_CS_GNU_LIBC_VERSION, str, n);
+ os::Linux::set_glibc_version(str);
+
+ n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
+ assert(n > 0, "cannot retrieve pthread version");
+ str = (char *)malloc(n, mtInternal);
+ confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
+ os::Linux::set_libpthread_version(str);
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// thread stack expansion
+
+// os::Linux::manually_expand_stack() takes care of expanding the thread
+// stack. Note that this is normally not needed: pthread stacks allocate
+// thread stack using mmap() without MAP_NORESERVE, so the stack is already
+// committed. Therefore it is not necessary to expand the stack manually.
+//
+// Manually expanding the stack was historically needed on LinuxThreads
+// thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays
+// it is kept to deal with very rare corner cases:
+//
+// For one, user may run the VM on an own implementation of threads
+// whose stacks are - like the old LinuxThreads - implemented using
+// mmap(MAP_GROWSDOWN).
+//
+// Also, this coding may be needed if the VM is running on the primordial
+// thread. Normally we avoid running on the primordial thread; however,
+// user may still invoke the VM on the primordial thread.
+//
+// The following historical comment describes the details about running
+// on a thread stack allocated with mmap(MAP_GROWSDOWN):
+
+
+// Force Linux kernel to expand current thread stack. If "bottom" is close
+// to the stack guard, caller should block all signals.
+//
+// MAP_GROWSDOWN:
+// A special mmap() flag that is used to implement thread stacks. It tells
+// kernel that the memory region should extend downwards when needed. This
+// allows early versions of LinuxThreads to only mmap the first few pages
+// when creating a new thread. Linux kernel will automatically expand thread
+// stack as needed (on page faults).
+//
+// However, because the memory region of a MAP_GROWSDOWN stack can grow on
+// demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
+// region, it's hard to tell if the fault is due to a legitimate stack
+// access or because of reading/writing non-exist memory (e.g. buffer
+// overrun). As a rule, if the fault happens below current stack pointer,
+// Linux kernel does not expand stack, instead a SIGSEGV is sent to the
+// application (see Linux kernel fault.c).
+//
+// This Linux feature can cause SIGSEGV when VM bangs thread stack for
+// stack overflow detection.
+//
+// Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
+// not use MAP_GROWSDOWN.
+//
+// To get around the problem and allow stack banging on Linux, we need to
+// manually expand thread stack after receiving the SIGSEGV.
+//
+// There are two ways to expand thread stack to address "bottom", we used
+// both of them in JVM before 1.5:
+// 1. adjust stack pointer first so that it is below "bottom", and then
+// touch "bottom"
+// 2. mmap() the page in question
+//
+// Now alternate signal stack is gone, it's harder to use 2. For instance,
+// if current sp is already near the lower end of page 101, and we need to
+// call mmap() to map page 100, it is possible that part of the mmap() frame
+// will be placed in page 100. When page 100 is mapped, it is zero-filled.
+// That will destroy the mmap() frame and cause VM to crash.
+//
+// The following code works by adjusting sp first, then accessing the "bottom"
+// page to force a page fault. Linux kernel will then automatically expand the
+// stack mapping.
+//
+// _expand_stack_to() assumes its frame size is less than page size, which
+// should always be true if the function is not inlined.
+
+static void NOINLINE _expand_stack_to(address bottom) {
+ address sp;
+ size_t size;
+ volatile char *p;
+
+ // Adjust bottom to point to the largest address within the same page, it
+ // gives us a one-page buffer if alloca() allocates slightly more memory.
+ bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size());
+ bottom += os::Linux::page_size() - 1;
+
+ // sp might be slightly above current stack pointer; if that's the case, we
+ // will alloca() a little more space than necessary, which is OK. Don't use
+ // os::current_stack_pointer(), as its result can be slightly below current
+ // stack pointer, causing us to not alloca enough to reach "bottom".
+ sp = (address)&sp;
+
+ if (sp > bottom) {
+ size = sp - bottom;
+ p = (volatile char *)alloca(size);
+ assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
+ p[0] = '\0';
+ }
+}
+
+bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
+ assert(t!=NULL, "just checking");
+ assert(t->osthread()->expanding_stack(), "expand should be set");
+ assert(t->stack_base() != NULL, "stack_base was not initialized");
+
+ if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) {
+ sigset_t mask_all, old_sigset;
+ sigfillset(&mask_all);
+ pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
+ _expand_stack_to(addr);
+ pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
+ return true;
+ }
+ return false;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// create new thread
+
+// Thread start routine for all newly created threads
+static void *thread_native_entry(Thread *thread) {
+ // Try to randomize the cache line index of hot stack frames.
+ // This helps when threads of the same stack traces evict each other's
+ // cache lines. The threads can be either from the same JVM instance, or
+ // from different JVM instances. The benefit is especially true for
+ // processors with hyperthreading technology.
+ static int counter = 0;
+ int pid = os::current_process_id();
+ alloca(((pid ^ counter++) & 7) * 128);
+
+ thread->initialize_thread_current();
+
+ OSThread* osthread = thread->osthread();
+ Monitor* sync = osthread->startThread_lock();
+
+ osthread->set_thread_id(os::current_thread_id());
+
+ log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+ os::current_thread_id(), (uintx) pthread_self());
+
+ if (UseNUMA) {
+ int lgrp_id = os::numa_get_group_id();
+ if (lgrp_id != -1) {
+ thread->set_lgrp_id(lgrp_id);
+ }
+ }
+ // initialize signal mask for this thread
+ os::Linux::hotspot_sigmask(thread);
+
+ // initialize floating point control register
+ os::Linux::init_thread_fpu_state();
+
+ // handshaking with parent thread
+ {
+ MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
+
+ // notify parent thread
+ osthread->set_state(INITIALIZED);
+ sync->notify_all();
+
+ // wait until os::start_thread()
+ while (osthread->get_state() == INITIALIZED) {
+ sync->wait(Mutex::_no_safepoint_check_flag);
+ }
+ }
+
+ // call one more level start routine
+ thread->run();
+
+ log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+ os::current_thread_id(), (uintx) pthread_self());
+
+ // If a thread has not deleted itself ("delete this") as part of its
+ // termination sequence, we have to ensure thread-local-storage is
+ // cleared before we actually terminate. No threads should ever be
+ // deleted asynchronously with respect to their termination.
+ if (Thread::current_or_null_safe() != NULL) {
+ assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
+ thread->clear_thread_current();
+ }
+
+ return 0;
+}
+
+bool os::create_thread(Thread* thread, ThreadType thr_type,
+ size_t req_stack_size) {
+ assert(thread->osthread() == NULL, "caller responsible");
+
+ // Allocate the OSThread object
+ OSThread* osthread = new OSThread(NULL, NULL);
+ if (osthread == NULL) {
+ return false;
+ }
+
+ // set the correct thread state
+ osthread->set_thread_type(thr_type);
+
+ // Initial state is ALLOCATED but not INITIALIZED
+ osthread->set_state(ALLOCATED);
+
+ thread->set_osthread(osthread);
+
+ // init thread attributes
+ pthread_attr_t attr;
+ pthread_attr_init(&attr);
+ pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+ // Calculate stack size if it's not specified by caller.
+ size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
+ // In the Linux NPTL pthread implementation the guard size mechanism
+ // is not implemented properly. The posix standard requires adding
+ // the size of the guard pages to the stack size, instead Linux
+ // takes the space out of 'stacksize'. Thus we adapt the requested
+ // stack_size by the size of the guard pages to mimick proper
+ // behaviour. However, be careful not to end up with a size
+ // of zero due to overflow. Don't add the guard page in that case.
+ size_t guard_size = os::Linux::default_guard_size(thr_type);
+ if (stack_size <= SIZE_MAX - guard_size) {
+ stack_size += guard_size;
+ }
+ assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned");
+
+ int status = pthread_attr_setstacksize(&attr, stack_size);
+ assert_status(status == 0, status, "pthread_attr_setstacksize");
+
+ // Configure glibc guard page.
+ pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
+
+ ThreadState state;
+
+ {
+ pthread_t tid;
+ int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
+
+ char buf[64];
+ if (ret == 0) {
+ log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
+ (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
+ } else {
+ log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
+ os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
+ }
+
+ pthread_attr_destroy(&attr);
+
+ if (ret != 0) {
+ // Need to clean up stuff we've allocated so far
+ thread->set_osthread(NULL);
+ delete osthread;
+ return false;
+ }
+
+ // Store pthread info into the OSThread
+ osthread->set_pthread_id(tid);
+
+ // Wait until child thread is either initialized or aborted
+ {
+ Monitor* sync_with_child = osthread->startThread_lock();
+ MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
+ while ((state = osthread->get_state()) == ALLOCATED) {
+ sync_with_child->wait(Mutex::_no_safepoint_check_flag);
+ }
+ }
+ }
+
+ // Aborted due to thread limit being reached
+ if (state == ZOMBIE) {
+ thread->set_osthread(NULL);
+ delete osthread;
+ return false;
+ }
+
+ // The thread is returned suspended (in state INITIALIZED),
+ // and is started higher up in the call chain
+ assert(state == INITIALIZED, "race condition");
+ return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// attach existing thread
+
+// bootstrap the main thread
+bool os::create_main_thread(JavaThread* thread) {
+ assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
+ return create_attached_thread(thread);
+}
+
+bool os::create_attached_thread(JavaThread* thread) {
+#ifdef ASSERT
+ thread->verify_not_published();
+#endif
+
+ // Allocate the OSThread object
+ OSThread* osthread = new OSThread(NULL, NULL);
+
+ if (osthread == NULL) {
+ return false;
+ }
+
+ // Store pthread info into the OSThread
+ osthread->set_thread_id(os::Linux::gettid());
+ osthread->set_pthread_id(::pthread_self());
+
+ // initialize floating point control register
+ os::Linux::init_thread_fpu_state();
+
+ // Initial thread state is RUNNABLE
+ osthread->set_state(RUNNABLE);
+
+ thread->set_osthread(osthread);
+
+ if (UseNUMA) {
+ int lgrp_id = os::numa_get_group_id();
+ if (lgrp_id != -1) {
+ thread->set_lgrp_id(lgrp_id);
+ }
+ }
+
+ if (os::Linux::is_initial_thread()) {
+ // If current thread is initial thread, its stack is mapped on demand,
+ // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
+ // the entire stack region to avoid SEGV in stack banging.
+ // It is also useful to get around the heap-stack-gap problem on SuSE
+ // kernel (see 4821821 for details). We first expand stack to the top
+ // of yellow zone, then enable stack yellow zone (order is significant,
+ // enabling yellow zone first will crash JVM on SuSE Linux), so there
+ // is no gap between the last two virtual memory regions.
+
+ JavaThread *jt = (JavaThread *)thread;
+ address addr = jt->stack_reserved_zone_base();
+ assert(addr != NULL, "initialization problem?");
+ assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
+
+ osthread->set_expanding_stack();
+ os::Linux::manually_expand_stack(jt, addr);
+ osthread->clear_expanding_stack();
+ }
+
+ // initialize signal mask for this thread
+ // and save the caller's signal mask
+ os::Linux::hotspot_sigmask(thread);
+
+ log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+ os::current_thread_id(), (uintx) pthread_self());
+
+ return true;
+}
+
+void os::pd_start_thread(Thread* thread) {
+ OSThread * osthread = thread->osthread();
+ assert(osthread->get_state() != INITIALIZED, "just checking");
+ Monitor* sync_with_child = osthread->startThread_lock();
+ MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
+ sync_with_child->notify();
+}
+
+// Free Linux resources related to the OSThread
+void os::free_thread(OSThread* osthread) {
+ assert(osthread != NULL, "osthread not set");
+
+ // We are told to free resources of the argument thread,
+ // but we can only really operate on the current thread.
+ assert(Thread::current()->osthread() == osthread,
+ "os::free_thread but not current thread");
+
+#ifdef ASSERT
+ sigset_t current;
+ sigemptyset(¤t);
+ pthread_sigmask(SIG_SETMASK, NULL, ¤t);
+ assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!");
+#endif
+
+ // Restore caller's signal mask
+ sigset_t sigmask = osthread->caller_sigmask();
+ pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
+
+ delete osthread;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// initial thread
+
+// Check if current thread is the initial thread, similar to Solaris thr_main.
+bool os::Linux::is_initial_thread(void) {
+ char dummy;
+ // If called before init complete, thread stack bottom will be null.
+ // Can be called if fatal error occurs before initialization.
+ if (initial_thread_stack_bottom() == NULL) return false;
+ assert(initial_thread_stack_bottom() != NULL &&
+ initial_thread_stack_size() != 0,
+ "os::init did not locate initial thread's stack region");
+ if ((address)&dummy >= initial_thread_stack_bottom() &&
+ (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+// Find the virtual memory area that contains addr
+static bool find_vma(address addr, address* vma_low, address* vma_high) {
+ FILE *fp = fopen("/proc/self/maps", "r");
+ if (fp) {
+ address low, high;
+ while (!feof(fp)) {
+ if (fscanf(fp, "%p-%p", &low, &high) == 2) {
+ if (low <= addr && addr < high) {
+ if (vma_low) *vma_low = low;
+ if (vma_high) *vma_high = high;
+ fclose(fp);
+ return true;
+ }
+ }
+ for (;;) {
+ int ch = fgetc(fp);
+ if (ch == EOF || ch == (int)'\n') break;
+ }
+ }
+ fclose(fp);
+ }
+ return false;
+}
+
+// Locate initial thread stack. This special handling of initial thread stack
+// is needed because pthread_getattr_np() on most (all?) Linux distros returns
+// bogus value for the primordial process thread. While the launcher has created
+// the VM in a new thread since JDK 6, we still have to allow for the use of the
+// JNI invocation API from a primordial thread.
+void os::Linux::capture_initial_stack(size_t max_size) {
+
+ // max_size is either 0 (which means accept OS default for thread stacks) or
+ // a user-specified value known to be at least the minimum needed. If we
+ // are actually on the primordial thread we can make it appear that we have a
+ // smaller max_size stack by inserting the guard pages at that location. But we
+ // cannot do anything to emulate a larger stack than what has been provided by
+ // the OS or threading library. In fact if we try to use a stack greater than
+ // what is set by rlimit then we will crash the hosting process.
+
+ // Maximum stack size is the easy part, get it from RLIMIT_STACK.
+ // If this is "unlimited" then it will be a huge value.
+ struct rlimit rlim;
+ getrlimit(RLIMIT_STACK, &rlim);
+ size_t stack_size = rlim.rlim_cur;
+
+ // 6308388: a bug in ld.so will relocate its own .data section to the
+ // lower end of primordial stack; reduce ulimit -s value a little bit
+ // so we won't install guard page on ld.so's data section.
+ stack_size -= 2 * page_size();
+
+ // Try to figure out where the stack base (top) is. This is harder.
+ //
+ // When an application is started, glibc saves the initial stack pointer in
+ // a global variable "__libc_stack_end", which is then used by system
+ // libraries. __libc_stack_end should be pretty close to stack top. The
+ // variable is available since the very early days. However, because it is
+ // a private interface, it could disappear in the future.
+ //
+ // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
+ // to __libc_stack_end, it is very close to stack top, but isn't the real
+ // stack top. Note that /proc may not exist if VM is running as a chroot
+ // program, so reading /proc/<pid>/stat could fail. Also the contents of
+ // /proc/<pid>/stat could change in the future (though unlikely).
+ //
+ // We try __libc_stack_end first. If that doesn't work, look for
+ // /proc/<pid>/stat. If neither of them works, we use current stack pointer
+ // as a hint, which should work well in most cases.
+
+ uintptr_t stack_start;
+
+ // try __libc_stack_end first
+ uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
+ if (p && *p) {
+ stack_start = *p;
+ } else {
+ // see if we can get the start_stack field from /proc/self/stat
+ FILE *fp;
+ int pid;
+ char state;
+ int ppid;
+ int pgrp;
+ int session;
+ int nr;
+ int tpgrp;
+ unsigned long flags;
+ unsigned long minflt;
+ unsigned long cminflt;
+ unsigned long majflt;
+ unsigned long cmajflt;
+ unsigned long utime;
+ unsigned long stime;
+ long cutime;
+ long cstime;
+ long prio;
+ long nice;
+ long junk;
+ long it_real;
+ uintptr_t start;
+ uintptr_t vsize;
+ intptr_t rss;
+ uintptr_t rsslim;
+ uintptr_t scodes;
+ uintptr_t ecode;
+ int i;
+
+ // Figure what the primordial thread stack base is. Code is inspired
+ // by email from Hans Boehm. /proc/self/stat begins with current pid,
+ // followed by command name surrounded by parentheses, state, etc.
+ char stat[2048];
+ int statlen;
+
+ fp = fopen("/proc/self/stat", "r");
+ if (fp) {
+ statlen = fread(stat, 1, 2047, fp);
+ stat[statlen] = '\0';
+ fclose(fp);
+
+ // Skip pid and the command string. Note that we could be dealing with
+ // weird command names, e.g. user could decide to rename java launcher
+ // to "java 1.4.2 :)", then the stat file would look like
+ // 1234 (java 1.4.2 :)) R ... ...
+ // We don't really need to know the command string, just find the last
+ // occurrence of ")" and then start parsing from there. See bug 4726580.
+ char * s = strrchr(stat, ')');
+
+ i = 0;
+ if (s) {
+ // Skip blank chars
+ do { s++; } while (s && isspace(*s));
+
+#define _UFM UINTX_FORMAT
+#define _DFM INTX_FORMAT
+
+ // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2
+ // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8
+ i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM,
+ &state, // 3 %c
+ &ppid, // 4 %d
+ &pgrp, // 5 %d
+ &session, // 6 %d
+ &nr, // 7 %d
+ &tpgrp, // 8 %d
+ &flags, // 9 %lu
+ &minflt, // 10 %lu
+ &cminflt, // 11 %lu
+ &majflt, // 12 %lu
+ &cmajflt, // 13 %lu
+ &utime, // 14 %lu
+ &stime, // 15 %lu
+ &cutime, // 16 %ld
+ &cstime, // 17 %ld
+ &prio, // 18 %ld
+ &nice, // 19 %ld
+ &junk, // 20 %ld
+ &it_real, // 21 %ld
+ &start, // 22 UINTX_FORMAT
+ &vsize, // 23 UINTX_FORMAT
+ &rss, // 24 INTX_FORMAT
+ &rsslim, // 25 UINTX_FORMAT
+ &scodes, // 26 UINTX_FORMAT
+ &ecode, // 27 UINTX_FORMAT
+ &stack_start); // 28 UINTX_FORMAT
+ }
+
+#undef _UFM
+#undef _DFM
+
+ if (i != 28 - 2) {
+ assert(false, "Bad conversion from /proc/self/stat");
+ // product mode - assume we are the initial thread, good luck in the
+ // embedded case.
+ warning("Can't detect initial thread stack location - bad conversion");
+ stack_start = (uintptr_t) &rlim;
+ }
+ } else {
+ // For some reason we can't open /proc/self/stat (for example, running on
+ // FreeBSD with a Linux emulator, or inside chroot), this should work for
+ // most cases, so don't abort:
+ warning("Can't detect initial thread stack location - no /proc/self/stat");
+ stack_start = (uintptr_t) &rlim;
+ }
+ }
+
+ // Now we have a pointer (stack_start) very close to the stack top, the
+ // next thing to do is to figure out the exact location of stack top. We
+ // can find out the virtual memory area that contains stack_start by
+ // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
+ // and its upper limit is the real stack top. (again, this would fail if
+ // running inside chroot, because /proc may not exist.)
+
+ uintptr_t stack_top;
+ address low, high;
+ if (find_vma((address)stack_start, &low, &high)) {
+ // success, "high" is the true stack top. (ignore "low", because initial
+ // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
+ stack_top = (uintptr_t)high;
+ } else {
+ // failed, likely because /proc/self/maps does not exist
+ warning("Can't detect initial thread stack location - find_vma failed");
+ // best effort: stack_start is normally within a few pages below the real
+ // stack top, use it as stack top, and reduce stack size so we won't put
+ // guard page outside stack.
+ stack_top = stack_start;
+ stack_size -= 16 * page_size();
+ }
+
+ // stack_top could be partially down the page so align it
+ stack_top = align_up(stack_top, page_size());
+
+ // Allowed stack value is minimum of max_size and what we derived from rlimit
+ if (max_size > 0) {
+ _initial_thread_stack_size = MIN2(max_size, stack_size);
+ } else {
+ // Accept the rlimit max, but if stack is unlimited then it will be huge, so
+ // clamp it at 8MB as we do on Solaris
+ _initial_thread_stack_size = MIN2(stack_size, 8*M);
+ }
+ _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size());
+ _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
+
+ assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!");
+
+ if (log_is_enabled(Info, os, thread)) {
+ // See if we seem to be on primordial process thread
+ bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) &&
+ uintptr_t(&rlim) < stack_top;
+
+ log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: "
+ SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT,
+ primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K,
+ stack_top, intptr_t(_initial_thread_stack_bottom));
+ }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// time support
+
+// Time since start-up in seconds to a fine granularity.
+// Used by VMSelfDestructTimer and the MemProfiler.
+double os::elapsedTime() {
+
+ return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
+}
+
+jlong os::elapsed_counter() {
+ return javaTimeNanos() - initial_time_count;
+}
+
+jlong os::elapsed_frequency() {
+ return NANOSECS_PER_SEC; // nanosecond resolution
+}
+
+bool os::supports_vtime() { return true; }
+bool os::enable_vtime() { return false; }
+bool os::vtime_enabled() { return false; }
+
+double os::elapsedVTime() {
+ struct rusage usage;
+ int retval = getrusage(RUSAGE_THREAD, &usage);
+ if (retval == 0) {
+ return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000);
+ } else {
+ // better than nothing, but not much
+ return elapsedTime();
+ }
+}
+
+jlong os::javaTimeMillis() {
+ timeval time;
+ int status = gettimeofday(&time, NULL);
+ assert(status != -1, "linux error");
+ return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
+}
+
+void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
+ timeval time;
+ int status = gettimeofday(&time, NULL);
+ assert(status != -1, "linux error");
+ seconds = jlong(time.tv_sec);
+ nanos = jlong(time.tv_usec) * 1000;
+}
+
+
+#ifndef CLOCK_MONOTONIC
+ #define CLOCK_MONOTONIC (1)
+#endif
+
+void os::Linux::clock_init() {
+ // we do dlopen's in this particular order due to bug in linux
+ // dynamical loader (see 6348968) leading to crash on exit
+ void* handle = dlopen("librt.so.1", RTLD_LAZY);
+ if (handle == NULL) {
+ handle = dlopen("librt.so", RTLD_LAZY);
+ }
+
+ if (handle) {
+ int (*clock_getres_func)(clockid_t, struct timespec*) =
+ (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
+ int (*clock_gettime_func)(clockid_t, struct timespec*) =
+ (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
+ if (clock_getres_func && clock_gettime_func) {
+ // See if monotonic clock is supported by the kernel. Note that some
+ // early implementations simply return kernel jiffies (updated every
+ // 1/100 or 1/1000 second). It would be bad to use such a low res clock
+ // for nano time (though the monotonic property is still nice to have).
+ // It's fixed in newer kernels, however clock_getres() still returns
+ // 1/HZ. We check if clock_getres() works, but will ignore its reported
+ // resolution for now. Hopefully as people move to new kernels, this
+ // won't be a problem.
+ struct timespec res;
+ struct timespec tp;
+ if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 &&
+ clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
+ // yes, monotonic clock is supported
+ _clock_gettime = clock_gettime_func;
+ return;
+ } else {
+ // close librt if there is no monotonic clock
+ dlclose(handle);
+ }
+ }
+ }
+ warning("No monotonic clock was available - timed services may " \
+ "be adversely affected if the time-of-day clock changes");
+}
+
+#ifndef SYS_clock_getres
+ #if defined(X86) || defined(PPC64) || defined(S390)
+ #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261)
+ #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
+ #else
+ #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time"
+ #define sys_clock_getres(x,y) -1
+ #endif
+#else
+ #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
+#endif
+
+void os::Linux::fast_thread_clock_init() {
+ if (!UseLinuxPosixThreadCPUClocks) {
+ return;
+ }
+ clockid_t clockid;
+ struct timespec tp;
+ int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
+ (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
+
+ // Switch to using fast clocks for thread cpu time if
+ // the sys_clock_getres() returns 0 error code.
+ // Note, that some kernels may support the current thread
+ // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
+ // returned by the pthread_getcpuclockid().
+ // If the fast Posix clocks are supported then the sys_clock_getres()
+ // must return at least tp.tv_sec == 0 which means a resolution
+ // better than 1 sec. This is extra check for reliability.
+
+ if (pthread_getcpuclockid_func &&
+ pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
+ sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
+ _supports_fast_thread_cpu_time = true;
+ _pthread_getcpuclockid = pthread_getcpuclockid_func;
+ }
+}
+
+jlong os::javaTimeNanos() {
+ if (os::supports_monotonic_clock()) {
+ struct timespec tp;
+ int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp);
+ assert(status == 0, "gettime error");
+ jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
+ return result;
+ } else {
+ timeval time;
+ int status = gettimeofday(&time, NULL);
+ assert(status != -1, "linux error");
+ jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
+ return 1000 * usecs;
+ }
+}
+
+void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
+ if (os::supports_monotonic_clock()) {
+ info_ptr->max_value = ALL_64_BITS;
+
+ // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
+ info_ptr->may_skip_backward = false; // not subject to resetting or drifting
+ info_ptr->may_skip_forward = false; // not subject to resetting or drifting
+ } else {
+ // gettimeofday - based on time in seconds since the Epoch thus does not wrap
+ info_ptr->max_value = ALL_64_BITS;
+
+ // gettimeofday is a real time clock so it skips
+ info_ptr->may_skip_backward = true;
+ info_ptr->may_skip_forward = true;
+ }
+
+ info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
+}
+
+// Return the real, user, and system times in seconds from an
+// arbitrary fixed point in the past.
+bool os::getTimesSecs(double* process_real_time,
+ double* process_user_time,
+ double* process_system_time) {
+ struct tms ticks;
+ clock_t real_ticks = times(&ticks);
+
+ if (real_ticks == (clock_t) (-1)) {
+ return false;
+ } else {
+ double ticks_per_second = (double) clock_tics_per_sec;
+ *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
+ *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
+ *process_real_time = ((double) real_ticks) / ticks_per_second;
+
+ return true;
+ }
+}
+
+
+char * os::local_time_string(char *buf, size_t buflen) {
+ struct tm t;
+ time_t long_time;
+ time(&long_time);
+ localtime_r(&long_time, &t);
+ jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
+ t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
+ t.tm_hour, t.tm_min, t.tm_sec);
+ return buf;
+}
+
+struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
+ return localtime_r(clock, res);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// runtime exit support
+
+// Note: os::shutdown() might be called very early during initialization, or
+// called from signal handler. Before adding something to os::shutdown(), make
+// sure it is async-safe and can handle partially initialized VM.
+void os::shutdown() {
+
+ // allow PerfMemory to attempt cleanup of any persistent resources
+ perfMemory_exit();
+
+ // needs to remove object in file system
+ AttachListener::abort();
+
+ // flush buffered output, finish log files
+ ostream_abort();
+
+ // Check for abort hook
+ abort_hook_t abort_hook = Arguments::abort_hook();
+ if (abort_hook != NULL) {
+ abort_hook();
+ }
+
+}
+
+// Note: os::abort() might be called very early during initialization, or
+// called from signal handler. Before adding something to os::abort(), make
+// sure it is async-safe and can handle partially initialized VM.
+void os::abort(bool dump_core, void* siginfo, const void* context) {
+ os::shutdown();
+ if (dump_core) {
+#ifndef PRODUCT
+ fdStream out(defaultStream::output_fd());
+ out.print_raw("Current thread is ");
+ char buf[16];
+ jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
+ out.print_raw_cr(buf);
+ out.print_raw_cr("Dumping core ...");
+#endif
+ ::abort(); // dump core
+ }
+
+ ::exit(1);
+}
+
+// Die immediately, no exit hook, no abort hook, no cleanup.
+void os::die() {
+ ::abort();
+}
+
+
+// This method is a copy of JDK's sysGetLastErrorString
+// from src/solaris/hpi/src/system_md.c
+
+size_t os::lasterror(char *buf, size_t len) {
+ if (errno == 0) return 0;
+
+ const char *s = os::strerror(errno);
+ size_t n = ::strlen(s);
+ if (n >= len) {
+ n = len - 1;
+ }
+ ::strncpy(buf, s, n);
+ buf[n] = '\0';
+ return n;
+}
+
+// thread_id is kernel thread id (similar to Solaris LWP id)
+intx os::current_thread_id() { return os::Linux::gettid(); }
+int os::current_process_id() {
+ return ::getpid();
+}
+
+// DLL functions
+
+const char* os::dll_file_extension() { return ".so"; }
+
+// This must be hard coded because it's the system's temporary
+// directory not the java application's temp directory, ala java.io.tmpdir.
+const char* os::get_temp_directory() { return "/tmp"; }
+
+static bool file_exists(const char* filename) {
+ struct stat statbuf;
+ if (filename == NULL || strlen(filename) == 0) {
+ return false;
+ }
+ return os::stat(filename, &statbuf) == 0;
+}
+
+// check if addr is inside libjvm.so
+bool os::address_is_in_vm(address addr) {
+ static address libjvm_base_addr;
+ Dl_info dlinfo;
+
+ if (libjvm_base_addr == NULL) {
+ if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
+ libjvm_base_addr = (address)dlinfo.dli_fbase;
+ }
+ assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
+ }
+
+ if (dladdr((void *)addr, &dlinfo) != 0) {
+ if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
+ }
+
+ return false;
+}
+
+bool os::dll_address_to_function_name(address addr, char *buf,
+ int buflen, int *offset,
+ bool demangle) {
+ // buf is not optional, but offset is optional
+ assert(buf != NULL, "sanity check");
+
+ Dl_info dlinfo;
+
+ if (dladdr((void*)addr, &dlinfo) != 0) {
+ // see if we have a matching symbol
+ if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
+ if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
+ jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
+ }
+ if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
+ return true;
+ }
+ // no matching symbol so try for just file info
+ if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
+ if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
+ buf, buflen, offset, dlinfo.dli_fname, demangle)) {
+ return true;
+ }
+ }
+ }
+
+ buf[0] = '\0';
+ if (offset != NULL) *offset = -1;
+ return false;
+}
+
+struct _address_to_library_name {
+ address addr; // input : memory address
+ size_t buflen; // size of fname
+ char* fname; // output: library name
+ address base; // library base addr
+};
+
+static int address_to_library_name_callback(struct dl_phdr_info *info,
+ size_t size, void *data) {
+ int i;
+ bool found = false;
+ address libbase = NULL;
+ struct _address_to_library_name * d = (struct _address_to_library_name *)data;
+
+ // iterate through all loadable segments
+ for (i = 0; i < info->dlpi_phnum; i++) {
+ address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
+ if (info->dlpi_phdr[i].p_type == PT_LOAD) {
+ // base address of a library is the lowest address of its loaded
+ // segments.
+ if (libbase == NULL || libbase > segbase) {
+ libbase = segbase;
+ }
+ // see if 'addr' is within current segment
+ if (segbase <= d->addr &&
+ d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
+ found = true;
+ }
+ }
+ }
+
+ // dlpi_name is NULL or empty if the ELF file is executable, return 0
+ // so dll_address_to_library_name() can fall through to use dladdr() which
+ // can figure out executable name from argv[0].
+ if (found && info->dlpi_name && info->dlpi_name[0]) {
+ d->base = libbase;
+ if (d->fname) {
+ jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
+ }
+ return 1;
+ }
+ return 0;
+}
+
+bool os::dll_address_to_library_name(address addr, char* buf,
+ int buflen, int* offset) {
+ // buf is not optional, but offset is optional
+ assert(buf != NULL, "sanity check");
+
+ Dl_info dlinfo;
+ struct _address_to_library_name data;
+
+ // There is a bug in old glibc dladdr() implementation that it could resolve
+ // to wrong library name if the .so file has a base address != NULL. Here
+ // we iterate through the program headers of all loaded libraries to find
+ // out which library 'addr' really belongs to. This workaround can be
+ // removed once the minimum requirement for glibc is moved to 2.3.x.
+ data.addr = addr;
+ data.fname = buf;
+ data.buflen = buflen;
+ data.base = NULL;
+ int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
+
+ if (rslt) {
+ // buf already contains library name
+ if (offset) *offset = addr - data.base;
+ return true;
+ }
+ if (dladdr((void*)addr, &dlinfo) != 0) {
+ if (dlinfo.dli_fname != NULL) {
+ jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
+ }
+ if (dlinfo.dli_fbase != NULL && offset != NULL) {
+ *offset = addr - (address)dlinfo.dli_fbase;
+ }
+ return true;
+ }
+
+ buf[0] = '\0';
+ if (offset) *offset = -1;
+ return false;
+}
+
+// Loads .dll/.so and
+// in case of error it checks if .dll/.so was built for the
+// same architecture as Hotspot is running on
+
+
+// Remember the stack's state. The Linux dynamic linker will change
+// the stack to 'executable' at most once, so we must safepoint only once.
+bool os::Linux::_stack_is_executable = false;
+
+// VM operation that loads a library. This is necessary if stack protection
+// of the Java stacks can be lost during loading the library. If we
+// do not stop the Java threads, they can stack overflow before the stacks
+// are protected again.
+class VM_LinuxDllLoad: public VM_Operation {
+ private:
+ const char *_filename;
+ char *_ebuf;
+ int _ebuflen;
+ void *_lib;
+ public:
+ VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) :
+ _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {}
+ VMOp_Type type() const { return VMOp_LinuxDllLoad; }
+ void doit() {
+ _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen);
+ os::Linux::_stack_is_executable = true;
+ }
+ void* loaded_library() { return _lib; }
+};
+
+void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
+ void * result = NULL;
+ bool load_attempted = false;
+
+ // Check whether the library to load might change execution rights
+ // of the stack. If they are changed, the protection of the stack
+ // guard pages will be lost. We need a safepoint to fix this.
+ //
+ // See Linux man page execstack(8) for more info.
+ if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) {
+ if (!ElfFile::specifies_noexecstack(filename)) {
+ if (!is_init_completed()) {
+ os::Linux::_stack_is_executable = true;
+ // This is OK - No Java threads have been created yet, and hence no
+ // stack guard pages to fix.
+ //
+ // This should happen only when you are building JDK7 using a very
+ // old version of JDK6 (e.g., with JPRT) and running test_gamma.
+ //
+ // Dynamic loader will make all stacks executable after
+ // this function returns, and will not do that again.
+ assert(Threads::first() == NULL, "no Java threads should exist yet.");
+ } else {
+ warning("You have loaded library %s which might have disabled stack guard. "
+ "The VM will try to fix the stack guard now.\n"
+ "It's highly recommended that you fix the library with "
+ "'execstack -c <libfile>', or link it with '-z noexecstack'.",
+ filename);
+
+ assert(Thread::current()->is_Java_thread(), "must be Java thread");
+ JavaThread *jt = JavaThread::current();
+ if (jt->thread_state() != _thread_in_native) {
+ // This happens when a compiler thread tries to load a hsdis-<arch>.so file
+ // that requires ExecStack. Cannot enter safe point. Let's give up.
+ warning("Unable to fix stack guard. Giving up.");
+ } else {
+ if (!LoadExecStackDllInVMThread) {
+ // This is for the case where the DLL has an static
+ // constructor function that executes JNI code. We cannot
+ // load such DLLs in the VMThread.
+ result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
+ }
+
+ ThreadInVMfromNative tiv(jt);
+ debug_only(VMNativeEntryWrapper vew;)
+
+ VM_LinuxDllLoad op(filename, ebuf, ebuflen);
+ VMThread::execute(&op);
+ if (LoadExecStackDllInVMThread) {
+ result = op.loaded_library();
+ }
+ load_attempted = true;
+ }
+ }
+ }
+ }
+
+ if (!load_attempted) {
+ result = os::Linux::dlopen_helper(filename, ebuf, ebuflen);
+ }
+
+ if (result != NULL) {
+ // Successful loading
+ return result;
+ }
+
+ Elf32_Ehdr elf_head;
+ int diag_msg_max_length=ebuflen-strlen(ebuf);
+ char* diag_msg_buf=ebuf+strlen(ebuf);
+
+ if (diag_msg_max_length==0) {
+ // No more space in ebuf for additional diagnostics message
+ return NULL;
+ }
+
+
+ int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
+
+ if (file_descriptor < 0) {
+ // Can't open library, report dlerror() message
+ return NULL;
+ }
+
+ bool failed_to_read_elf_head=
+ (sizeof(elf_head)!=
+ (::read(file_descriptor, &elf_head,sizeof(elf_head))));
+
+ ::close(file_descriptor);
+ if (failed_to_read_elf_head) {
+ // file i/o error - report dlerror() msg
+ return NULL;
+ }
+
+ typedef struct {
+ Elf32_Half code; // Actual value as defined in elf.h
+ Elf32_Half compat_class; // Compatibility of archs at VM's sense
+ unsigned char elf_class; // 32 or 64 bit
+ unsigned char endianess; // MSB or LSB
+ char* name; // String representation
+ } arch_t;
+
+#ifndef EM_486
+ #define EM_486 6 /* Intel 80486 */
+#endif
+#ifndef EM_AARCH64
+ #define EM_AARCH64 183 /* ARM AARCH64 */
+#endif
+
+ static const arch_t arch_array[]={
+ {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
+ {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
+ {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
+ {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
+ {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
+ {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
+ {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
+ {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
+#if defined(VM_LITTLE_ENDIAN)
+ {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"},
+ {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"},
+#else
+ {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
+ {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"},
+#endif
+ {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
+ {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
+ {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
+ {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
+ {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
+ {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
+ {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"},
+ {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"},
+ };
+
+#if (defined IA32)
+ static Elf32_Half running_arch_code=EM_386;
+#elif (defined AMD64)
+ static Elf32_Half running_arch_code=EM_X86_64;
+#elif (defined IA64)
+ static Elf32_Half running_arch_code=EM_IA_64;
+#elif (defined __sparc) && (defined _LP64)
+ static Elf32_Half running_arch_code=EM_SPARCV9;
+#elif (defined __sparc) && (!defined _LP64)
+ static Elf32_Half running_arch_code=EM_SPARC;
+#elif (defined __powerpc64__)
+ static Elf32_Half running_arch_code=EM_PPC64;
+#elif (defined __powerpc__)
+ static Elf32_Half running_arch_code=EM_PPC;
+#elif (defined AARCH64)
+ static Elf32_Half running_arch_code=EM_AARCH64;
+#elif (defined ARM)
+ static Elf32_Half running_arch_code=EM_ARM;
+#elif (defined S390)
+ static Elf32_Half running_arch_code=EM_S390;
+#elif (defined ALPHA)
+ static Elf32_Half running_arch_code=EM_ALPHA;
+#elif (defined MIPSEL)
+ static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
+#elif (defined PARISC)
+ static Elf32_Half running_arch_code=EM_PARISC;
+#elif (defined MIPS)
+ static Elf32_Half running_arch_code=EM_MIPS;
+#elif (defined M68K)
+ static Elf32_Half running_arch_code=EM_68K;
+#elif (defined SH)
+ static Elf32_Half running_arch_code=EM_SH;
+#else
+ #error Method os::dll_load requires that one of following is defined:\
+ AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc
+#endif
+
+ // Identify compatability class for VM's architecture and library's architecture
+ // Obtain string descriptions for architectures
+
+ arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
+ int running_arch_index=-1;
+
+ for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
+ if (running_arch_code == arch_array[i].code) {
+ running_arch_index = i;
+ }
+ if (lib_arch.code == arch_array[i].code) {
+ lib_arch.compat_class = arch_array[i].compat_class;
+ lib_arch.name = arch_array[i].name;
+ }
+ }
+
+ assert(running_arch_index != -1,
+ "Didn't find running architecture code (running_arch_code) in arch_array");
+ if (running_arch_index == -1) {
+ // Even though running architecture detection failed
+ // we may still continue with reporting dlerror() message
+ return NULL;
+ }
+
+ if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
+ ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
+ return NULL;
+ }
+
+#ifndef S390
+ if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
+ ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
+ return NULL;
+ }
+#endif // !S390
+
+ if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
+ if (lib_arch.name!=NULL) {
+ ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+ " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
+ lib_arch.name, arch_array[running_arch_index].name);
+ } else {
+ ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+ " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
+ lib_arch.code,
+ arch_array[running_arch_index].name);
+ }
+ }
+
+ return NULL;
+}
+
+void * os::Linux::dlopen_helper(const char *filename, char *ebuf,
+ int ebuflen) {
+ void * result = ::dlopen(filename, RTLD_LAZY);
+ if (result == NULL) {
+ ::strncpy(ebuf, ::dlerror(), ebuflen - 1);
+ ebuf[ebuflen-1] = '\0';
+ }
+ return result;
+}
+
+void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf,
+ int ebuflen) {
+ void * result = NULL;
+ if (LoadExecStackDllInVMThread) {
+ result = dlopen_helper(filename, ebuf, ebuflen);
+ }
+
+ // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a
+ // library that requires an executable stack, or which does not have this
+ // stack attribute set, dlopen changes the stack attribute to executable. The
+ // read protection of the guard pages gets lost.
+ //
+ // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad
+ // may have been queued at the same time.
+
+ if (!_stack_is_executable) {
+ JavaThread *jt = Threads::first();
+
+ while (jt) {
+ if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized
+ jt->stack_guards_enabled()) { // No pending stack overflow exceptions
+ if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) {
+ warning("Attempt to reguard stack yellow zone failed.");
+ }
+ }
+ jt = jt->next();
+ }
+ }
+
+ return result;
+}
+
+void* os::dll_lookup(void* handle, const char* name) {
+ void* res = dlsym(handle, name);
+ return res;
+}
+
+void* os::get_default_process_handle() {
+ return (void*)::dlopen(NULL, RTLD_LAZY);
+}
+
+static bool _print_ascii_file(const char* filename, outputStream* st) {
+ int fd = ::open(filename, O_RDONLY);
+ if (fd == -1) {
+ return false;
+ }
+
+ char buf[33];
+ int bytes;
+ buf[32] = '\0';
+ while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) {
+ st->print_raw(buf, bytes);
+ }
+
+ ::close(fd);
+
+ return true;
+}
+
+void os::print_dll_info(outputStream *st) {
+ st->print_cr("Dynamic libraries:");
+
+ char fname[32];
+ pid_t pid = os::Linux::gettid();
+
+ jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
+
+ if (!_print_ascii_file(fname, st)) {
+ st->print("Can not get library information for pid = %d\n", pid);
+ }
+}
+
+int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
+ FILE *procmapsFile = NULL;
+
+ // Open the procfs maps file for the current process
+ if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) {
+ // Allocate PATH_MAX for file name plus a reasonable size for other fields.
+ char line[PATH_MAX + 100];
+
+ // Read line by line from 'file'
+ while (fgets(line, sizeof(line), procmapsFile) != NULL) {
+ u8 base, top, offset, inode;
+ char permissions[5];
+ char device[6];
+ char name[PATH_MAX + 1];
+
+ // Parse fields from line
+ sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s",
+ &base, &top, permissions, &offset, device, &inode, name);
+
+ // Filter by device id '00:00' so that we only get file system mapped files.
+ if (strcmp(device, "00:00") != 0) {
+
+ // Call callback with the fields of interest
+ if(callback(name, (address)base, (address)top, param)) {
+ // Oops abort, callback aborted
+ fclose(procmapsFile);
+ return 1;
+ }
+ }
+ }
+ fclose(procmapsFile);
+ }
+ return 0;
+}
+
+void os::print_os_info_brief(outputStream* st) {
+ os::Linux::print_distro_info(st);
+
+ os::Posix::print_uname_info(st);
+
+ os::Linux::print_libversion_info(st);
+
+}
+
+void os::print_os_info(outputStream* st) {
+ st->print("OS:");
+
+ os::Linux::print_distro_info(st);
+
+ os::Posix::print_uname_info(st);
+
+ // Print warning if unsafe chroot environment detected
+ if (unsafe_chroot_detected) {
+ st->print("WARNING!! ");
+ st->print_cr("%s", unstable_chroot_error);
+ }
+
+ os::Linux::print_libversion_info(st);
+
+ os::Posix::print_rlimit_info(st);
+
+ os::Posix::print_load_average(st);
+
+ os::Linux::print_full_memory_info(st);
+}
+
+// Try to identify popular distros.
+// Most Linux distributions have a /etc/XXX-release file, which contains
+// the OS version string. Newer Linux distributions have a /etc/lsb-release
+// file that also contains the OS version string. Some have more than one
+// /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and
+// /etc/redhat-release.), so the order is important.
+// Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have
+// their own specific XXX-release file as well as a redhat-release file.
+// Because of this the XXX-release file needs to be searched for before the
+// redhat-release file.
+// Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
+// search for redhat-release / SuSE-release needs to be before lsb-release.
+// Since the lsb-release file is the new standard it needs to be searched
+// before the older style release files.
+// Searching system-release (Red Hat) and os-release (other Linuxes) are a
+// next to last resort. The os-release file is a new standard that contains
+// distribution information and the system-release file seems to be an old
+// standard that has been replaced by the lsb-release and os-release files.
+// Searching for the debian_version file is the last resort. It contains
+// an informative string like "6.0.6" or "wheezy/sid". Because of this
+// "Debian " is printed before the contents of the debian_version file.
+
+const char* distro_files[] = {
+ "/etc/oracle-release",
+ "/etc/mandriva-release",
+ "/etc/mandrake-release",
+ "/etc/sun-release",
+ "/etc/redhat-release",
+ "/etc/SuSE-release",
+ "/etc/lsb-release",
+ "/etc/turbolinux-release",
+ "/etc/gentoo-release",
+ "/etc/ltib-release",
+ "/etc/angstrom-version",
+ "/etc/system-release",
+ "/etc/os-release",
+ NULL };
+
+void os::Linux::print_distro_info(outputStream* st) {
+ for (int i = 0;; i++) {
+ const char* file = distro_files[i];
+ if (file == NULL) {
+ break; // done
+ }
+ // If file prints, we found it.
+ if (_print_ascii_file(file, st)) {
+ return;
+ }
+ }
+
+ if (file_exists("/etc/debian_version")) {
+ st->print("Debian ");
+ _print_ascii_file("/etc/debian_version", st);
+ } else {
+ st->print("Linux");
+ }
+ st->cr();
+}
+
+static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) {
+ char buf[256];
+ while (fgets(buf, sizeof(buf), fp)) {
+ // Edit out extra stuff in expected format
+ if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
+ char* ptr = strstr(buf, "\""); // the name is in quotes
+ if (ptr != NULL) {
+ ptr++; // go beyond first quote
+ char* nl = strchr(ptr, '\"');
+ if (nl != NULL) *nl = '\0';
+ strncpy(distro, ptr, length);
+ } else {
+ ptr = strstr(buf, "=");
+ ptr++; // go beyond equals then
+ char* nl = strchr(ptr, '\n');
+ if (nl != NULL) *nl = '\0';
+ strncpy(distro, ptr, length);
+ }
+ return;
+ } else if (get_first_line) {
+ char* nl = strchr(buf, '\n');
+ if (nl != NULL) *nl = '\0';
+ strncpy(distro, buf, length);
+ return;
+ }
+ }
+ // print last line and close
+ char* nl = strchr(buf, '\n');
+ if (nl != NULL) *nl = '\0';
+ strncpy(distro, buf, length);
+}
+
+static void parse_os_info(char* distro, size_t length, const char* file) {
+ FILE* fp = fopen(file, "r");
+ if (fp != NULL) {
+ // if suse format, print out first line
+ bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0);
+ parse_os_info_helper(fp, distro, length, get_first_line);
+ fclose(fp);
+ }
+}
+
+void os::get_summary_os_info(char* buf, size_t buflen) {
+ for (int i = 0;; i++) {
+ const char* file = distro_files[i];
+ if (file == NULL) {
+ break; // ran out of distro_files
+ }
+ if (file_exists(file)) {
+ parse_os_info(buf, buflen, file);
+ return;
+ }
+ }
+ // special case for debian
+ if (file_exists("/etc/debian_version")) {
+ strncpy(buf, "Debian ", buflen);
+ parse_os_info(&buf[7], buflen-7, "/etc/debian_version");
+ } else {
+ strncpy(buf, "Linux", buflen);
+ }
+}
+
+void os::Linux::print_libversion_info(outputStream* st) {
+ // libc, pthread
+ st->print("libc:");
+ st->print("%s ", os::Linux::glibc_version());
+ st->print("%s ", os::Linux::libpthread_version());
+ st->cr();
+}
+
+void os::Linux::print_full_memory_info(outputStream* st) {
+ st->print("\n/proc/meminfo:\n");
+ _print_ascii_file("/proc/meminfo", st);
+ st->cr();
+}
+
+void os::print_memory_info(outputStream* st) {
+
+ st->print("Memory:");
+ st->print(" %dk page", os::vm_page_size()>>10);
+
+ // values in struct sysinfo are "unsigned long"
+ struct sysinfo si;
+ sysinfo(&si);
+
+ st->print(", physical " UINT64_FORMAT "k",
+ os::physical_memory() >> 10);
+ st->print("(" UINT64_FORMAT "k free)",
+ os::available_memory() >> 10);
+ st->print(", swap " UINT64_FORMAT "k",
+ ((jlong)si.totalswap * si.mem_unit) >> 10);
+ st->print("(" UINT64_FORMAT "k free)",
+ ((jlong)si.freeswap * si.mem_unit) >> 10);
+ st->cr();
+}
+
+// Print the first "model name" line and the first "flags" line
+// that we find and nothing more. We assume "model name" comes
+// before "flags" so if we find a second "model name", then the
+// "flags" field is considered missing.
+static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
+#if defined(IA32) || defined(AMD64)
+ // Other platforms have less repetitive cpuinfo files
+ FILE *fp = fopen("/proc/cpuinfo", "r");
+ if (fp) {
+ while (!feof(fp)) {
+ if (fgets(buf, buflen, fp)) {
+ // Assume model name comes before flags
+ bool model_name_printed = false;
+ if (strstr(buf, "model name") != NULL) {
+ if (!model_name_printed) {
+ st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
+ st->print_raw(buf);
+ model_name_printed = true;
+ } else {
+ // model name printed but not flags? Odd, just return
+ fclose(fp);
+ return true;
+ }
+ }
+ // print the flags line too
+ if (strstr(buf, "flags") != NULL) {
+ st->print_raw(buf);
+ fclose(fp);
+ return true;
+ }
+ }
+ }
+ fclose(fp);
+ }
+#endif // x86 platforms
+ return false;
+}
+
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
+ // Only print the model name if the platform provides this as a summary
+ if (!print_model_name_and_flags(st, buf, buflen)) {
+ st->print("\n/proc/cpuinfo:\n");
+ if (!_print_ascii_file("/proc/cpuinfo", st)) {
+ st->print_cr(" <Not Available>");
+ }
+ }
+}
+
+#if defined(AMD64) || defined(IA32) || defined(X32)
+const char* search_string = "model name";
+#elif defined(M68K)
+const char* search_string = "CPU";
+#elif defined(PPC64)
+const char* search_string = "cpu";
+#elif defined(S390)
+const char* search_string = "processor";
+#elif defined(SPARC)
+const char* search_string = "cpu";
+#else
+const char* search_string = "Processor";
+#endif
+
+// Parses the cpuinfo file for string representing the model name.
+void os::get_summary_cpu_info(char* cpuinfo, size_t length) {
+ FILE* fp = fopen("/proc/cpuinfo", "r");
+ if (fp != NULL) {
+ while (!feof(fp)) {
+ char buf[256];
+ if (fgets(buf, sizeof(buf), fp)) {
+ char* start = strstr(buf, search_string);
+ if (start != NULL) {
+ char *ptr = start + strlen(search_string);
+ char *end = buf + strlen(buf);
+ while (ptr != end) {
+ // skip whitespace and colon for the rest of the name.
+ if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') {
+ break;
+ }
+ ptr++;
+ }
+ if (ptr != end) {
+ // reasonable string, get rid of newline and keep the rest
+ char* nl = strchr(buf, '\n');
+ if (nl != NULL) *nl = '\0';
+ strncpy(cpuinfo, ptr, length);
+ fclose(fp);
+ return;
+ }
+ }
+ }
+ }
+ fclose(fp);
+ }
+ // cpuinfo not found or parsing failed, just print generic string. The entire
+ // /proc/cpuinfo file will be printed later in the file (or enough of it for x86)
+#if defined(AARCH64)
+ strncpy(cpuinfo, "AArch64", length);
+#elif defined(AMD64)
+ strncpy(cpuinfo, "x86_64", length);
+#elif defined(ARM) // Order wrt. AARCH64 is relevant!
+ strncpy(cpuinfo, "ARM", length);
+#elif defined(IA32)
+ strncpy(cpuinfo, "x86_32", length);
+#elif defined(IA64)
+ strncpy(cpuinfo, "IA64", length);
+#elif defined(PPC)
+ strncpy(cpuinfo, "PPC64", length);
+#elif defined(S390)
+ strncpy(cpuinfo, "S390", length);
+#elif defined(SPARC)
+ strncpy(cpuinfo, "sparcv9", length);
+#elif defined(ZERO_LIBARCH)
+ strncpy(cpuinfo, ZERO_LIBARCH, length);
+#else
+ strncpy(cpuinfo, "unknown", length);
+#endif
+}
+
+static void print_signal_handler(outputStream* st, int sig,
+ char* buf, size_t buflen);
+
+void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
+ st->print_cr("Signal Handlers:");
+ print_signal_handler(st, SIGSEGV, buf, buflen);
+ print_signal_handler(st, SIGBUS , buf, buflen);
+ print_signal_handler(st, SIGFPE , buf, buflen);
+ print_signal_handler(st, SIGPIPE, buf, buflen);
+ print_signal_handler(st, SIGXFSZ, buf, buflen);
+ print_signal_handler(st, SIGILL , buf, buflen);
+ print_signal_handler(st, SR_signum, buf, buflen);
+ print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
+ print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
+ print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
+ print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
+#if defined(PPC64)
+ print_signal_handler(st, SIGTRAP, buf, buflen);
+#endif
+}
+
+static char saved_jvm_path[MAXPATHLEN] = {0};
+
+// Find the full path to the current module, libjvm.so
+void os::jvm_path(char *buf, jint buflen) {
+ // Error checking.
+ if (buflen < MAXPATHLEN) {
+ assert(false, "must use a large-enough buffer");
+ buf[0] = '\0';
+ return;
+ }
+ // Lazy resolve the path to current module.
+ if (saved_jvm_path[0] != 0) {
+ strcpy(buf, saved_jvm_path);
+ return;
+ }
+
+ char dli_fname[MAXPATHLEN];
+ bool ret = dll_address_to_library_name(
+ CAST_FROM_FN_PTR(address, os::jvm_path),
+ dli_fname, sizeof(dli_fname), NULL);
+ assert(ret, "cannot locate libjvm");
+ char *rp = NULL;
+ if (ret && dli_fname[0] != '\0') {
+ rp = os::Posix::realpath(dli_fname, buf, buflen);
+ }
+ if (rp == NULL) {
+ return;
+ }
+
+ if (Arguments::sun_java_launcher_is_altjvm()) {
+ // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
+ // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so".
+ // If "/jre/lib/" appears at the right place in the string, then
+ // assume we are installed in a JDK and we're done. Otherwise, check
+ // for a JAVA_HOME environment variable and fix up the path so it
+ // looks like libjvm.so is installed there (append a fake suffix
+ // hotspot/libjvm.so).
+ const char *p = buf + strlen(buf) - 1;
+ for (int count = 0; p > buf && count < 5; ++count) {
+ for (--p; p > buf && *p != '/'; --p)
+ /* empty */ ;
+ }
+
+ if (strncmp(p, "/jre/lib/", 9) != 0) {
+ // Look for JAVA_HOME in the environment.
+ char* java_home_var = ::getenv("JAVA_HOME");
+ if (java_home_var != NULL && java_home_var[0] != 0) {
+ char* jrelib_p;
+ int len;
+
+ // Check the current module name "libjvm.so".
+ p = strrchr(buf, '/');
+ if (p == NULL) {
+ return;
+ }
+ assert(strstr(p, "/libjvm") == p, "invalid library name");
+
+ rp = os::Posix::realpath(java_home_var, buf, buflen);
+ if (rp == NULL) {
+ return;
+ }
+
+ // determine if this is a legacy image or modules image
+ // modules image doesn't have "jre" subdirectory
+ len = strlen(buf);
+ assert(len < buflen, "Ran out of buffer room");
+ jrelib_p = buf + len;
+ snprintf(jrelib_p, buflen-len, "/jre/lib");
+ if (0 != access(buf, F_OK)) {
+ snprintf(jrelib_p, buflen-len, "/lib");
+ }
+
+ if (0 == access(buf, F_OK)) {
+ // Use current module name "libjvm.so"
+ len = strlen(buf);
+ snprintf(buf + len, buflen-len, "/hotspot/libjvm.so");
+ } else {
+ // Go back to path of .so
+ rp = os::Posix::realpath(dli_fname, buf, buflen);
+ if (rp == NULL) {
+ return;
+ }
+ }
+ }
+ }
+ }
+
+ strncpy(saved_jvm_path, buf, MAXPATHLEN);
+ saved_jvm_path[MAXPATHLEN - 1] = '\0';
+}
+
+void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
+ // no prefix required, not even "_"
+}
+
+void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
+ // no suffix required
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// sun.misc.Signal support
+
+static volatile jint sigint_count = 0;
+
+static void UserHandler(int sig, void *siginfo, void *context) {
+ // 4511530 - sem_post is serialized and handled by the manager thread. When
+ // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
+ // don't want to flood the manager thread with sem_post requests.
+ if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
+ return;
+ }
+
+ // Ctrl-C is pressed during error reporting, likely because the error
+ // handler fails to abort. Let VM die immediately.
+ if (sig == SIGINT && VMError::is_error_reported()) {
+ os::die();
+ }
+
+ os::signal_notify(sig);
+}
+
+void* os::user_handler() {
+ return CAST_FROM_FN_PTR(void*, UserHandler);
+}
+
+struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
+ struct timespec ts;
+ // Semaphore's are always associated with CLOCK_REALTIME
+ os::Linux::clock_gettime(CLOCK_REALTIME, &ts);
+ // see unpackTime for discussion on overflow checking
+ if (sec >= MAX_SECS) {
+ ts.tv_sec += MAX_SECS;
+ ts.tv_nsec = 0;
+ } else {
+ ts.tv_sec += sec;
+ ts.tv_nsec += nsec;
+ if (ts.tv_nsec >= NANOSECS_PER_SEC) {
+ ts.tv_nsec -= NANOSECS_PER_SEC;
+ ++ts.tv_sec; // note: this must be <= max_secs
+ }
+ }
+
+ return ts;
+}
+
+extern "C" {
+ typedef void (*sa_handler_t)(int);
+ typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
+}
+
+void* os::signal(int signal_number, void* handler) {
+ struct sigaction sigAct, oldSigAct;
+
+ sigfillset(&(sigAct.sa_mask));
+ sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
+ sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
+
+ if (sigaction(signal_number, &sigAct, &oldSigAct)) {
+ // -1 means registration failed
+ return (void *)-1;
+ }
+
+ return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
+}
+
+void os::signal_raise(int signal_number) {
+ ::raise(signal_number);
+}
+
+// The following code is moved from os.cpp for making this
+// code platform specific, which it is by its very nature.
+
+// Will be modified when max signal is changed to be dynamic
+int os::sigexitnum_pd() {
+ return NSIG;
+}
+
+// a counter for each possible signal value
+static volatile jint pending_signals[NSIG+1] = { 0 };
+
+// Linux(POSIX) specific hand shaking semaphore.
+static sem_t sig_sem;
+static PosixSemaphore sr_semaphore;
+
+void os::signal_init_pd() {
+ // Initialize signal structures
+ ::memset((void*)pending_signals, 0, sizeof(pending_signals));
+
+ // Initialize signal semaphore
+ ::sem_init(&sig_sem, 0, 0);
+}
+
+void os::signal_notify(int sig) {
+ Atomic::inc(&pending_signals[sig]);
+ ::sem_post(&sig_sem);
+}
+
+static int check_pending_signals(bool wait) {
+ Atomic::store(0, &sigint_count);
+ for (;;) {
+ for (int i = 0; i < NSIG + 1; i++) {
+ jint n = pending_signals[i];
+ if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
+ return i;
+ }
+ }
+ if (!wait) {
+ return -1;
+ }
+ JavaThread *thread = JavaThread::current();
+ ThreadBlockInVM tbivm(thread);
+
+ bool threadIsSuspended;
+ do {
+ thread->set_suspend_equivalent();
+ // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
+ ::sem_wait(&sig_sem);
+
+ // were we externally suspended while we were waiting?
+ threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
+ if (threadIsSuspended) {
+ // The semaphore has been incremented, but while we were waiting
+ // another thread suspended us. We don't want to continue running
+ // while suspended because that would surprise the thread that
+ // suspended us.
+ ::sem_post(&sig_sem);
+
+ thread->java_suspend_self();
+ }
+ } while (threadIsSuspended);
+ }
+}
+
+int os::signal_lookup() {
+ return check_pending_signals(false);
+}
+
+int os::signal_wait() {
+ return check_pending_signals(true);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Virtual Memory
+
+int os::vm_page_size() {
+ // Seems redundant as all get out
+ assert(os::Linux::page_size() != -1, "must call os::init");
+ return os::Linux::page_size();
+}
+
+// Solaris allocates memory by pages.
+int os::vm_allocation_granularity() {
+ assert(os::Linux::page_size() != -1, "must call os::init");
+ return os::Linux::page_size();
+}
+
+// Rationale behind this function:
+// current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
+// mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
+// samples for JITted code. Here we create private executable mapping over the code cache
+// and then we can use standard (well, almost, as mapping can change) way to provide
+// info for the reporting script by storing timestamp and location of symbol
+void linux_wrap_code(char* base, size_t size) {
+ static volatile jint cnt = 0;
+
+ if (!UseOprofile) {
+ return;
+ }
+
+ char buf[PATH_MAX+1];
+ int num = Atomic::add(1, &cnt);
+
+ snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d",
+ os::get_temp_directory(), os::current_process_id(), num);
+ unlink(buf);
+
+ int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
+
+ if (fd != -1) {
+ off_t rv = ::lseek(fd, size-2, SEEK_SET);
+ if (rv != (off_t)-1) {
+ if (::write(fd, "", 1) == 1) {
+ mmap(base, size,
+ PROT_READ|PROT_WRITE|PROT_EXEC,
+ MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
+ }
+ }
+ ::close(fd);
+ unlink(buf);
+ }
+}
+
+static bool recoverable_mmap_error(int err) {
+ // See if the error is one we can let the caller handle. This
+ // list of errno values comes from JBS-6843484. I can't find a
+ // Linux man page that documents this specific set of errno
+ // values so while this list currently matches Solaris, it may
+ // change as we gain experience with this failure mode.
+ switch (err) {
+ case EBADF:
+ case EINVAL:
+ case ENOTSUP:
+ // let the caller deal with these errors
+ return true;
+
+ default:
+ // Any remaining errors on this OS can cause our reserved mapping
+ // to be lost. That can cause confusion where different data
+ // structures think they have the same memory mapped. The worst
+ // scenario is if both the VM and a library think they have the
+ // same memory mapped.
+ return false;
+ }
+}
+
+static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
+ int err) {
+ warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
+ ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec,
+ os::strerror(err), err);
+}
+
+static void warn_fail_commit_memory(char* addr, size_t size,
+ size_t alignment_hint, bool exec,
+ int err) {
+ warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
+ ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size,
+ alignment_hint, exec, os::strerror(err), err);
+}
+
+// NOTE: Linux kernel does not really reserve the pages for us.
+// All it does is to check if there are enough free pages
+// left at the time of mmap(). This could be a potential
+// problem.
+int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) {
+ int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
+ uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
+ MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
+ if (res != (uintptr_t) MAP_FAILED) {
+ if (UseNUMAInterleaving) {
+ numa_make_global(addr, size);
+ }
+ return 0;
+ }
+
+ int err = errno; // save errno from mmap() call above
+
+ if (!recoverable_mmap_error(err)) {
+ warn_fail_commit_memory(addr, size, exec, err);
+ vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory.");
+ }
+
+ return err;
+}
+
+bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
+ return os::Linux::commit_memory_impl(addr, size, exec) == 0;
+}
+
+void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
+ const char* mesg) {
+ assert(mesg != NULL, "mesg must be specified");
+ int err = os::Linux::commit_memory_impl(addr, size, exec);
+ if (err != 0) {
+ // the caller wants all commit errors to exit with the specified mesg:
+ warn_fail_commit_memory(addr, size, exec, err);
+ vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
+ }
+}
+
+// Define MAP_HUGETLB here so we can build HotSpot on old systems.
+#ifndef MAP_HUGETLB
+ #define MAP_HUGETLB 0x40000
+#endif
+
+// Define MADV_HUGEPAGE here so we can build HotSpot on old systems.
+#ifndef MADV_HUGEPAGE
+ #define MADV_HUGEPAGE 14
+#endif
+
+int os::Linux::commit_memory_impl(char* addr, size_t size,
+ size_t alignment_hint, bool exec) {
+ int err = os::Linux::commit_memory_impl(addr, size, exec);
+ if (err == 0) {
+ realign_memory(addr, size, alignment_hint);
+ }
+ return err;
+}
+
+bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
+ bool exec) {
+ return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0;
+}
+
+void os::pd_commit_memory_or_exit(char* addr, size_t size,
+ size_t alignment_hint, bool exec,
+ const char* mesg) {
+ assert(mesg != NULL, "mesg must be specified");
+ int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec);
+ if (err != 0) {
+ // the caller wants all commit errors to exit with the specified mesg:
+ warn_fail_commit_memory(addr, size, alignment_hint, exec, err);
+ vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
+ }
+}
+
+void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
+ if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) {
+ // We don't check the return value: madvise(MADV_HUGEPAGE) may not
+ // be supported or the memory may already be backed by huge pages.
+ ::madvise(addr, bytes, MADV_HUGEPAGE);
+ }
+}
+
+void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
+ // This method works by doing an mmap over an existing mmaping and effectively discarding
+ // the existing pages. However it won't work for SHM-based large pages that cannot be
+ // uncommitted at all. We don't do anything in this case to avoid creating a segment with
+ // small pages on top of the SHM segment. This method always works for small pages, so we
+ // allow that in any case.
+ if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) {
+ commit_memory(addr, bytes, alignment_hint, !ExecMem);
+ }
+}
+
+void os::numa_make_global(char *addr, size_t bytes) {
+ Linux::numa_interleave_memory(addr, bytes);
+}
+
+// Define for numa_set_bind_policy(int). Setting the argument to 0 will set the
+// bind policy to MPOL_PREFERRED for the current thread.
+#define USE_MPOL_PREFERRED 0
+
+void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
+ // To make NUMA and large pages more robust when both enabled, we need to ease
+ // the requirements on where the memory should be allocated. MPOL_BIND is the
+ // default policy and it will force memory to be allocated on the specified
+ // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on
+ // the specified node, but will not force it. Using this policy will prevent
+ // getting SIGBUS when trying to allocate large pages on NUMA nodes with no
+ // free large pages.
+ Linux::numa_set_bind_policy(USE_MPOL_PREFERRED);
+ Linux::numa_tonode_memory(addr, bytes, lgrp_hint);
+}
+
+bool os::numa_topology_changed() { return false; }
+
+size_t os::numa_get_groups_num() {
+ // Return just the number of nodes in which it's possible to allocate memory
+ // (in numa terminology, configured nodes).
+ return Linux::numa_num_configured_nodes();
+}
+
+int os::numa_get_group_id() {
+ int cpu_id = Linux::sched_getcpu();
+ if (cpu_id != -1) {
+ int lgrp_id = Linux::get_node_by_cpu(cpu_id);
+ if (lgrp_id != -1) {
+ return lgrp_id;
+ }
+ }
+ return 0;
+}
+
+int os::Linux::get_existing_num_nodes() {
+ size_t node;
+ size_t highest_node_number = Linux::numa_max_node();
+ int num_nodes = 0;
+
+ // Get the total number of nodes in the system including nodes without memory.
+ for (node = 0; node <= highest_node_number; node++) {
+ if (isnode_in_existing_nodes(node)) {
+ num_nodes++;
+ }
+ }
+ return num_nodes;
+}
+
+size_t os::numa_get_leaf_groups(int *ids, size_t size) {
+ size_t highest_node_number = Linux::numa_max_node();
+ size_t i = 0;
+
+ // Map all node ids in which is possible to allocate memory. Also nodes are
+ // not always consecutively available, i.e. available from 0 to the highest
+ // node number.
+ for (size_t node = 0; node <= highest_node_number; node++) {
+ if (Linux::isnode_in_configured_nodes(node)) {
+ ids[i++] = node;
+ }
+ }
+ return i;
+}
+
+bool os::get_page_info(char *start, page_info* info) {
+ return false;
+}
+
+char *os::scan_pages(char *start, char* end, page_info* page_expected,
+ page_info* page_found) {
+ return end;
+}
+
+
+int os::Linux::sched_getcpu_syscall(void) {
+ unsigned int cpu = 0;
+ int retval = -1;
+
+#if defined(IA32)
+ #ifndef SYS_getcpu
+ #define SYS_getcpu 318
+ #endif
+ retval = syscall(SYS_getcpu, &cpu, NULL, NULL);
+#elif defined(AMD64)
+// Unfortunately we have to bring all these macros here from vsyscall.h
+// to be able to compile on old linuxes.
+ #define __NR_vgetcpu 2
+ #define VSYSCALL_START (-10UL << 20)
+ #define VSYSCALL_SIZE 1024
+ #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
+ typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache);
+ vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu);
+ retval = vgetcpu(&cpu, NULL, NULL);
+#endif
+
+ return (retval == -1) ? retval : cpu;
+}
+
+void os::Linux::sched_getcpu_init() {
+ // sched_getcpu() should be in libc.
+ set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
+ dlsym(RTLD_DEFAULT, "sched_getcpu")));
+
+ // If it's not, try a direct syscall.
+ if (sched_getcpu() == -1) {
+ set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t,
+ (void*)&sched_getcpu_syscall));
+ }
+}
+
+// Something to do with the numa-aware allocator needs these symbols
+extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { }
+extern "C" JNIEXPORT void numa_error(char *where) { }
+
+// Handle request to load libnuma symbol version 1.1 (API v1). If it fails
+// load symbol from base version instead.
+void* os::Linux::libnuma_dlsym(void* handle, const char *name) {
+ void *f = dlvsym(handle, name, "libnuma_1.1");
+ if (f == NULL) {
+ f = dlsym(handle, name);
+ }
+ return f;
+}
+
+// Handle request to load libnuma symbol version 1.2 (API v2) only.
+// Return NULL if the symbol is not defined in this particular version.
+void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) {
+ return dlvsym(handle, name, "libnuma_1.2");
+}
+
+bool os::Linux::libnuma_init() {
+ if (sched_getcpu() != -1) { // Requires sched_getcpu() support
+ void *handle = dlopen("libnuma.so.1", RTLD_LAZY);
+ if (handle != NULL) {
+ set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t,
+ libnuma_dlsym(handle, "numa_node_to_cpus")));
+ set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t,
+ libnuma_dlsym(handle, "numa_max_node")));
+ set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t,
+ libnuma_dlsym(handle, "numa_num_configured_nodes")));
+ set_numa_available(CAST_TO_FN_PTR(numa_available_func_t,
+ libnuma_dlsym(handle, "numa_available")));
+ set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t,
+ libnuma_dlsym(handle, "numa_tonode_memory")));
+ set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t,
+ libnuma_dlsym(handle, "numa_interleave_memory")));
+ set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t,
+ libnuma_v2_dlsym(handle, "numa_interleave_memory")));
+ set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t,
+ libnuma_dlsym(handle, "numa_set_bind_policy")));
+ set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t,
+ libnuma_dlsym(handle, "numa_bitmask_isbitset")));
+ set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t,
+ libnuma_dlsym(handle, "numa_distance")));
+
+ if (numa_available() != -1) {
+ set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes"));
+ set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr"));
+ set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr"));
+ // Create an index -> node mapping, since nodes are not always consecutive
+ _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
+ rebuild_nindex_to_node_map();
+ // Create a cpu -> node mapping
+ _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true);
+ rebuild_cpu_to_node_map();
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
+ // Creating guard page is very expensive. Java thread has HotSpot
+ // guard pages, only enable glibc guard page for non-Java threads.
+ // (Remember: compiler thread is a Java thread, too!)
+ return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size());
+}
+
+void os::Linux::rebuild_nindex_to_node_map() {
+ int highest_node_number = Linux::numa_max_node();
+
+ nindex_to_node()->clear();
+ for (int node = 0; node <= highest_node_number; node++) {
+ if (Linux::isnode_in_existing_nodes(node)) {
+ nindex_to_node()->append(node);
+ }
+ }
+}
+
+// rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id.
+// The table is later used in get_node_by_cpu().
+void os::Linux::rebuild_cpu_to_node_map() {
+ const size_t NCPUS = 32768; // Since the buffer size computation is very obscure
+ // in libnuma (possible values are starting from 16,
+ // and continuing up with every other power of 2, but less
+ // than the maximum number of CPUs supported by kernel), and
+ // is a subject to change (in libnuma version 2 the requirements
+ // are more reasonable) we'll just hardcode the number they use
+ // in the library.
+ const size_t BitsPerCLong = sizeof(long) * CHAR_BIT;
+
+ size_t cpu_num = processor_count();
+ size_t cpu_map_size = NCPUS / BitsPerCLong;
+ size_t cpu_map_valid_size =
+ MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size);
+
+ cpu_to_node()->clear();
+ cpu_to_node()->at_grow(cpu_num - 1);
+
+ size_t node_num = get_existing_num_nodes();
+
+ int distance = 0;
+ int closest_distance = INT_MAX;
+ int closest_node = 0;
+ unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal);
+ for (size_t i = 0; i < node_num; i++) {
+ // Check if node is configured (not a memory-less node). If it is not, find
+ // the closest configured node.
+ if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) {
+ closest_distance = INT_MAX;
+ // Check distance from all remaining nodes in the system. Ignore distance
+ // from itself and from another non-configured node.
+ for (size_t m = 0; m < node_num; m++) {
+ if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) {
+ distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m));
+ // If a closest node is found, update. There is always at least one
+ // configured node in the system so there is always at least one node
+ // close.
+ if (distance != 0 && distance < closest_distance) {
+ closest_distance = distance;
+ closest_node = nindex_to_node()->at(m);
+ }
+ }
+ }
+ } else {
+ // Current node is already a configured node.
+ closest_node = nindex_to_node()->at(i);
+ }
+
+ // Get cpus from the original node and map them to the closest node. If node
+ // is a configured node (not a memory-less node), then original node and
+ // closest node are the same.
+ if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) {
+ for (size_t j = 0; j < cpu_map_valid_size; j++) {
+ if (cpu_map[j] != 0) {
+ for (size_t k = 0; k < BitsPerCLong; k++) {
+ if (cpu_map[j] & (1UL << k)) {
+ cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node);
+ }
+ }
+ }
+ }
+ }
+ }
+ FREE_C_HEAP_ARRAY(unsigned long, cpu_map);
+}
+
+int os::Linux::get_node_by_cpu(int cpu_id) {
+ if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) {
+ return cpu_to_node()->at(cpu_id);
+ }
+ return -1;
+}
+
+GrowableArray<int>* os::Linux::_cpu_to_node;
+GrowableArray<int>* os::Linux::_nindex_to_node;
+os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu;
+os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus;
+os::Linux::numa_max_node_func_t os::Linux::_numa_max_node;
+os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes;
+os::Linux::numa_available_func_t os::Linux::_numa_available;
+os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory;
+os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory;
+os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2;
+os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy;
+os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset;
+os::Linux::numa_distance_func_t os::Linux::_numa_distance;
+unsigned long* os::Linux::_numa_all_nodes;
+struct bitmask* os::Linux::_numa_all_nodes_ptr;
+struct bitmask* os::Linux::_numa_nodes_ptr;
+
+bool os::pd_uncommit_memory(char* addr, size_t size) {
+ uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
+ MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
+ return res != (uintptr_t) MAP_FAILED;
+}
+
+static address get_stack_commited_bottom(address bottom, size_t size) {
+ address nbot = bottom;
+ address ntop = bottom + size;
+
+ size_t page_sz = os::vm_page_size();
+ unsigned pages = size / page_sz;
+
+ unsigned char vec[1];
+ unsigned imin = 1, imax = pages + 1, imid;
+ int mincore_return_value = 0;
+
+ assert(imin <= imax, "Unexpected page size");
+
+ while (imin < imax) {
+ imid = (imax + imin) / 2;
+ nbot = ntop - (imid * page_sz);
+
+ // Use a trick with mincore to check whether the page is mapped or not.
+ // mincore sets vec to 1 if page resides in memory and to 0 if page
+ // is swapped output but if page we are asking for is unmapped
+ // it returns -1,ENOMEM
+ mincore_return_value = mincore(nbot, page_sz, vec);
+
+ if (mincore_return_value == -1) {
+ // Page is not mapped go up
+ // to find first mapped page
+ if (errno != EAGAIN) {
+ assert(errno == ENOMEM, "Unexpected mincore errno");
+ imax = imid;
+ }
+ } else {
+ // Page is mapped go down
+ // to find first not mapped page
+ imin = imid + 1;
+ }
+ }
+
+ nbot = nbot + page_sz;
+
+ // Adjust stack bottom one page up if last checked page is not mapped
+ if (mincore_return_value == -1) {
+ nbot = nbot + page_sz;
+ }
+
+ return nbot;
+}
+
+
+// Linux uses a growable mapping for the stack, and if the mapping for
+// the stack guard pages is not removed when we detach a thread the
+// stack cannot grow beyond the pages where the stack guard was
+// mapped. If at some point later in the process the stack expands to
+// that point, the Linux kernel cannot expand the stack any further
+// because the guard pages are in the way, and a segfault occurs.
+//
+// However, it's essential not to split the stack region by unmapping
+// a region (leaving a hole) that's already part of the stack mapping,
+// so if the stack mapping has already grown beyond the guard pages at
+// the time we create them, we have to truncate the stack mapping.
+// So, we need to know the extent of the stack mapping when
+// create_stack_guard_pages() is called.
+
+// We only need this for stacks that are growable: at the time of
+// writing thread stacks don't use growable mappings (i.e. those
+// creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this
+// only applies to the main thread.
+
+// If the (growable) stack mapping already extends beyond the point
+// where we're going to put our guard pages, truncate the mapping at
+// that point by munmap()ping it. This ensures that when we later
+// munmap() the guard pages we don't leave a hole in the stack
+// mapping. This only affects the main/initial thread
+
+bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
+ if (os::Linux::is_initial_thread()) {
+ // As we manually grow stack up to bottom inside create_attached_thread(),
+ // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
+ // we don't need to do anything special.
+ // Check it first, before calling heavy function.
+ uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom();
+ unsigned char vec[1];
+
+ if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) {
+ // Fallback to slow path on all errors, including EAGAIN
+ stack_extent = (uintptr_t) get_stack_commited_bottom(
+ os::Linux::initial_thread_stack_bottom(),
+ (size_t)addr - stack_extent);
+ }
+
+ if (stack_extent < (uintptr_t)addr) {
+ ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent));
+ }
+ }
+
+ return os::commit_memory(addr, size, !ExecMem);
+}
+
+// If this is a growable mapping, remove the guard pages entirely by
+// munmap()ping them. If not, just call uncommit_memory(). This only
+// affects the main/initial thread, but guard against future OS changes
+// It's safe to always unmap guard pages for initial thread because we
+// always place it right after end of the mapped region
+
+bool os::remove_stack_guard_pages(char* addr, size_t size) {
+ uintptr_t stack_extent, stack_base;
+
+ if (os::Linux::is_initial_thread()) {
+ return ::munmap(addr, size) == 0;
+ }
+
+ return os::uncommit_memory(addr, size);
+}
+
+// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
+// at 'requested_addr'. If there are existing memory mappings at the same
+// location, however, they will be overwritten. If 'fixed' is false,
+// 'requested_addr' is only treated as a hint, the return value may or
+// may not start from the requested address. Unlike Linux mmap(), this
+// function returns NULL to indicate failure.
+static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
+ char * addr;
+ int flags;
+
+ flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
+ if (fixed) {
+ assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
+ flags |= MAP_FIXED;
+ }
+
+ // Map reserved/uncommitted pages PROT_NONE so we fail early if we
+ // touch an uncommitted page. Otherwise, the read/write might
+ // succeed if we have enough swap space to back the physical page.
+ addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
+ flags, -1, 0);
+
+ return addr == MAP_FAILED ? NULL : addr;
+}
+
+// Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address
+// (req_addr != NULL) or with a given alignment.
+// - bytes shall be a multiple of alignment.
+// - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
+// - alignment sets the alignment at which memory shall be allocated.
+// It must be a multiple of allocation granularity.
+// Returns address of memory or NULL. If req_addr was not NULL, will only return
+// req_addr or NULL.
+static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) {
+
+ size_t extra_size = bytes;
+ if (req_addr == NULL && alignment > 0) {
+ extra_size += alignment;
+ }
+
+ char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
+ -1, 0);
+ if (start == MAP_FAILED) {
+ start = NULL;
+ } else {
+ if (req_addr != NULL) {
+ if (start != req_addr) {
+ ::munmap(start, extra_size);
+ start = NULL;
+ }
+ } else {
+ char* const start_aligned = align_up(start, alignment);
+ char* const end_aligned = start_aligned + bytes;
+ char* const end = start + extra_size;
+ if (start_aligned > start) {
+ ::munmap(start, start_aligned - start);
+ }
+ if (end_aligned < end) {
+ ::munmap(end_aligned, end - end_aligned);
+ }
+ start = start_aligned;
+ }
+ }
+ return start;
+}
+
+static int anon_munmap(char * addr, size_t size) {
+ return ::munmap(addr, size) == 0;
+}
+
+char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
+ size_t alignment_hint) {
+ return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
+}
+
+bool os::pd_release_memory(char* addr, size_t size) {
+ return anon_munmap(addr, size);
+}
+
+static bool linux_mprotect(char* addr, size_t size, int prot) {
+ // Linux wants the mprotect address argument to be page aligned.
+ char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size());
+
+ // According to SUSv3, mprotect() should only be used with mappings
+ // established by mmap(), and mmap() always maps whole pages. Unaligned
+ // 'addr' likely indicates problem in the VM (e.g. trying to change
+ // protection of malloc'ed or statically allocated memory). Check the
+ // caller if you hit this assert.
+ assert(addr == bottom, "sanity check");
+
+ size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
+ return ::mprotect(bottom, size, prot) == 0;
+}
+
+// Set protections specified
+bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
+ bool is_committed) {
+ unsigned int p = 0;
+ switch (prot) {
+ case MEM_PROT_NONE: p = PROT_NONE; break;
+ case MEM_PROT_READ: p = PROT_READ; break;
+ case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
+ case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
+ default:
+ ShouldNotReachHere();
+ }
+ // is_committed is unused.
+ return linux_mprotect(addr, bytes, p);
+}
+
+bool os::guard_memory(char* addr, size_t size) {
+ return linux_mprotect(addr, size, PROT_NONE);
+}
+
+bool os::unguard_memory(char* addr, size_t size) {
+ return linux_mprotect(addr, size, PROT_READ|PROT_WRITE);
+}
+
+bool os::Linux::transparent_huge_pages_sanity_check(bool warn,
+ size_t page_size) {
+ bool result = false;
+ void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE,
+ -1, 0);
+ if (p != MAP_FAILED) {
+ void *aligned_p = align_up(p, page_size);
+
+ result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0;
+
+ munmap(p, page_size * 2);
+ }
+
+ if (warn && !result) {
+ warning("TransparentHugePages is not supported by the operating system.");
+ }
+
+ return result;
+}
+
+bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
+ bool result = false;
+ void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB,
+ -1, 0);
+
+ if (p != MAP_FAILED) {
+ // We don't know if this really is a huge page or not.
+ FILE *fp = fopen("/proc/self/maps", "r");
+ if (fp) {
+ while (!feof(fp)) {
+ char chars[257];
+ long x = 0;
+ if (fgets(chars, sizeof(chars), fp)) {
+ if (sscanf(chars, "%lx-%*x", &x) == 1
+ && x == (long)p) {
+ if (strstr (chars, "hugepage")) {
+ result = true;
+ break;
+ }
+ }
+ }
+ }
+ fclose(fp);
+ }
+ munmap(p, page_size);
+ }
+
+ if (warn && !result) {
+ warning("HugeTLBFS is not supported by the operating system.");
+ }
+
+ return result;
+}
+
+// Set the coredump_filter bits to include largepages in core dump (bit 6)
+//
+// From the coredump_filter documentation:
+//
+// - (bit 0) anonymous private memory
+// - (bit 1) anonymous shared memory
+// - (bit 2) file-backed private memory
+// - (bit 3) file-backed shared memory
+// - (bit 4) ELF header pages in file-backed private memory areas (it is
+// effective only if the bit 2 is cleared)
+// - (bit 5) hugetlb private memory
+// - (bit 6) hugetlb shared memory
+//
+static void set_coredump_filter(void) {
+ FILE *f;
+ long cdm;
+
+ if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
+ return;
+ }
+
+ if (fscanf(f, "%lx", &cdm) != 1) {
+ fclose(f);
+ return;
+ }
+
+ rewind(f);
+
+ if ((cdm & LARGEPAGES_BIT) == 0) {
+ cdm |= LARGEPAGES_BIT;
+ fprintf(f, "%#lx", cdm);
+ }
+
+ fclose(f);
+}
+
+// Large page support
+
+static size_t _large_page_size = 0;
+
+size_t os::Linux::find_large_page_size() {
+ size_t large_page_size = 0;
+
+ // large_page_size on Linux is used to round up heap size. x86 uses either
+ // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
+ // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
+ // page as large as 256M.
+ //
+ // Here we try to figure out page size by parsing /proc/meminfo and looking
+ // for a line with the following format:
+ // Hugepagesize: 2048 kB
+ //
+ // If we can't determine the value (e.g. /proc is not mounted, or the text
+ // format has been changed), we'll use the largest page size supported by
+ // the processor.
+
+#ifndef ZERO
+ large_page_size =
+ AARCH64_ONLY(2 * M)
+ AMD64_ONLY(2 * M)
+ ARM32_ONLY(2 * M)
+ IA32_ONLY(4 * M)
+ IA64_ONLY(256 * M)
+ PPC_ONLY(4 * M)
+ S390_ONLY(1 * M)
+ SPARC_ONLY(4 * M);
+#endif // ZERO
+
+ FILE *fp = fopen("/proc/meminfo", "r");
+ if (fp) {
+ while (!feof(fp)) {
+ int x = 0;
+ char buf[16];
+ if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
+ if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
+ large_page_size = x * K;
+ break;
+ }
+ } else {
+ // skip to next line
+ for (;;) {
+ int ch = fgetc(fp);
+ if (ch == EOF || ch == (int)'\n') break;
+ }
+ }
+ }
+ fclose(fp);
+ }
+
+ if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) {
+ warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is "
+ SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size),
+ proper_unit_for_byte_size(large_page_size));
+ }
+
+ return large_page_size;
+}
+
+size_t os::Linux::setup_large_page_size() {
+ _large_page_size = Linux::find_large_page_size();
+ const size_t default_page_size = (size_t)Linux::page_size();
+ if (_large_page_size > default_page_size) {
+ _page_sizes[0] = _large_page_size;
+ _page_sizes[1] = default_page_size;
+ _page_sizes[2] = 0;
+ }
+
+ return _large_page_size;
+}
+
+bool os::Linux::setup_large_page_type(size_t page_size) {
+ if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
+ FLAG_IS_DEFAULT(UseSHM) &&
+ FLAG_IS_DEFAULT(UseTransparentHugePages)) {
+
+ // The type of large pages has not been specified by the user.
+
+ // Try UseHugeTLBFS and then UseSHM.
+ UseHugeTLBFS = UseSHM = true;
+
+ // Don't try UseTransparentHugePages since there are known
+ // performance issues with it turned on. This might change in the future.
+ UseTransparentHugePages = false;
+ }
+
+ if (UseTransparentHugePages) {
+ bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages);
+ if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) {
+ UseHugeTLBFS = false;
+ UseSHM = false;
+ return true;
+ }
+ UseTransparentHugePages = false;
+ }
+
+ if (UseHugeTLBFS) {
+ bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS);
+ if (hugetlbfs_sanity_check(warn_on_failure, page_size)) {
+ UseSHM = false;
+ return true;
+ }
+ UseHugeTLBFS = false;
+ }
+
+ return UseSHM;
+}
+
+void os::large_page_init() {
+ if (!UseLargePages &&
+ !UseTransparentHugePages &&
+ !UseHugeTLBFS &&
+ !UseSHM) {
+ // Not using large pages.
+ return;
+ }
+
+ if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
+ // The user explicitly turned off large pages.
+ // Ignore the rest of the large pages flags.
+ UseTransparentHugePages = false;
+ UseHugeTLBFS = false;
+ UseSHM = false;
+ return;
+ }
+
+ size_t large_page_size = Linux::setup_large_page_size();
+ UseLargePages = Linux::setup_large_page_type(large_page_size);
+
+ set_coredump_filter();
+}
+
+#ifndef SHM_HUGETLB
+ #define SHM_HUGETLB 04000
+#endif
+
+#define shm_warning_format(format, ...) \
+ do { \
+ if (UseLargePages && \
+ (!FLAG_IS_DEFAULT(UseLargePages) || \
+ !FLAG_IS_DEFAULT(UseSHM) || \
+ !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \
+ warning(format, __VA_ARGS__); \
+ } \
+ } while (0)
+
+#define shm_warning(str) shm_warning_format("%s", str)
+
+#define shm_warning_with_errno(str) \
+ do { \
+ int err = errno; \
+ shm_warning_format(str " (error = %d)", err); \
+ } while (0)
+
+static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) {
+ assert(is_aligned(bytes, alignment), "Must be divisible by the alignment");
+
+ if (!is_aligned(alignment, SHMLBA)) {
+ assert(false, "Code below assumes that alignment is at least SHMLBA aligned");
+ return NULL;
+ }
+
+ // To ensure that we get 'alignment' aligned memory from shmat,
+ // we pre-reserve aligned virtual memory and then attach to that.
+
+ char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL);
+ if (pre_reserved_addr == NULL) {
+ // Couldn't pre-reserve aligned memory.
+ shm_warning("Failed to pre-reserve aligned memory for shmat.");
+ return NULL;
+ }
+
+ // SHM_REMAP is needed to allow shmat to map over an existing mapping.
+ char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP);
+
+ if ((intptr_t)addr == -1) {
+ int err = errno;
+ shm_warning_with_errno("Failed to attach shared memory.");
+
+ assert(err != EACCES, "Unexpected error");
+ assert(err != EIDRM, "Unexpected error");
+ assert(err != EINVAL, "Unexpected error");
+
+ // Since we don't know if the kernel unmapped the pre-reserved memory area
+ // we can't unmap it, since that would potentially unmap memory that was
+ // mapped from other threads.
+ return NULL;
+ }
+
+ return addr;
+}
+
+static char* shmat_at_address(int shmid, char* req_addr) {
+ if (!is_aligned(req_addr, SHMLBA)) {
+ assert(false, "Requested address needs to be SHMLBA aligned");
+ return NULL;
+ }
+
+ char* addr = (char*)shmat(shmid, req_addr, 0);
+
+ if ((intptr_t)addr == -1) {
+ shm_warning_with_errno("Failed to attach shared memory.");
+ return NULL;
+ }
+
+ return addr;
+}
+
+static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) {
+ // If a req_addr has been provided, we assume that the caller has already aligned the address.
+ if (req_addr != NULL) {
+ assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size");
+ assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment");
+ return shmat_at_address(shmid, req_addr);
+ }
+
+ // Since shmid has been setup with SHM_HUGETLB, shmat will automatically
+ // return large page size aligned memory addresses when req_addr == NULL.
+ // However, if the alignment is larger than the large page size, we have
+ // to manually ensure that the memory returned is 'alignment' aligned.
+ if (alignment > os::large_page_size()) {
+ assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size");
+ return shmat_with_alignment(shmid, bytes, alignment);
+ } else {
+ return shmat_at_address(shmid, NULL);
+ }
+}
+
+char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment,
+ char* req_addr, bool exec) {
+ // "exec" is passed in but not used. Creating the shared image for
+ // the code cache doesn't have an SHM_X executable permission to check.
+ assert(UseLargePages && UseSHM, "only for SHM large pages");
+ assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
+ assert(is_aligned(req_addr, alignment), "Unaligned address");
+
+ if (!is_aligned(bytes, os::large_page_size())) {
+ return NULL; // Fallback to small pages.
+ }
+
+ // Create a large shared memory region to attach to based on size.
+ // Currently, size is the total size of the heap.
+ int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
+ if (shmid == -1) {
+ // Possible reasons for shmget failure:
+ // 1. shmmax is too small for Java heap.
+ // > check shmmax value: cat /proc/sys/kernel/shmmax
+ // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
+ // 2. not enough large page memory.
+ // > check available large pages: cat /proc/meminfo
+ // > increase amount of large pages:
+ // echo new_value > /proc/sys/vm/nr_hugepages
+ // Note 1: different Linux may use different name for this property,
+ // e.g. on Redhat AS-3 it is "hugetlb_pool".
+ // Note 2: it's possible there's enough physical memory available but
+ // they are so fragmented after a long run that they can't
+ // coalesce into large pages. Try to reserve large pages when
+ // the system is still "fresh".
+ shm_warning_with_errno("Failed to reserve shared memory.");
+ return NULL;
+ }
+
+ // Attach to the region.
+ char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr);
+
+ // Remove shmid. If shmat() is successful, the actual shared memory segment
+ // will be deleted when it's detached by shmdt() or when the process
+ // terminates. If shmat() is not successful this will remove the shared
+ // segment immediately.
+ shmctl(shmid, IPC_RMID, NULL);
+
+ return addr;
+}
+
+static void warn_on_large_pages_failure(char* req_addr, size_t bytes,
+ int error) {
+ assert(error == ENOMEM, "Only expect to fail if no memory is available");
+
+ bool warn_on_failure = UseLargePages &&
+ (!FLAG_IS_DEFAULT(UseLargePages) ||
+ !FLAG_IS_DEFAULT(UseHugeTLBFS) ||
+ !FLAG_IS_DEFAULT(LargePageSizeInBytes));
+
+ if (warn_on_failure) {
+ char msg[128];
+ jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: "
+ PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error);
+ warning("%s", msg);
+ }
+}
+
+char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes,
+ char* req_addr,
+ bool exec) {
+ assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
+ assert(is_aligned(bytes, os::large_page_size()), "Unaligned size");
+ assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address");
+
+ int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
+ char* addr = (char*)::mmap(req_addr, bytes, prot,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB,
+ -1, 0);
+
+ if (addr == MAP_FAILED) {
+ warn_on_large_pages_failure(req_addr, bytes, errno);
+ return NULL;
+ }
+
+ assert(is_aligned(addr, os::large_page_size()), "Must be");
+
+ return addr;
+}
+
+// Reserve memory using mmap(MAP_HUGETLB).
+// - bytes shall be a multiple of alignment.
+// - req_addr can be NULL. If not NULL, it must be a multiple of alignment.
+// - alignment sets the alignment at which memory shall be allocated.
+// It must be a multiple of allocation granularity.
+// Returns address of memory or NULL. If req_addr was not NULL, will only return
+// req_addr or NULL.
+char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes,
+ size_t alignment,
+ char* req_addr,
+ bool exec) {
+ size_t large_page_size = os::large_page_size();
+ assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes");
+
+ assert(is_aligned(req_addr, alignment), "Must be");
+ assert(is_aligned(bytes, alignment), "Must be");
+
+ // First reserve - but not commit - the address range in small pages.
+ char* const start = anon_mmap_aligned(bytes, alignment, req_addr);
+
+ if (start == NULL) {
+ return NULL;
+ }
+
+ assert(is_aligned(start, alignment), "Must be");
+
+ char* end = start + bytes;
+
+ // Find the regions of the allocated chunk that can be promoted to large pages.
+ char* lp_start = align_up(start, large_page_size);
+ char* lp_end = align_down(end, large_page_size);
+
+ size_t lp_bytes = lp_end - lp_start;
+
+ assert(is_aligned(lp_bytes, large_page_size), "Must be");
+
+ if (lp_bytes == 0) {
+ // The mapped region doesn't even span the start and the end of a large page.
+ // Fall back to allocate a non-special area.
+ ::munmap(start, end - start);
+ return NULL;
+ }
+
+ int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
+
+ void* result;
+
+ // Commit small-paged leading area.
+ if (start != lp_start) {
+ result = ::mmap(start, lp_start - start, prot,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
+ -1, 0);
+ if (result == MAP_FAILED) {
+ ::munmap(lp_start, end - lp_start);
+ return NULL;
+ }
+ }
+
+ // Commit large-paged area.
+ result = ::mmap(lp_start, lp_bytes, prot,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB,
+ -1, 0);
+ if (result == MAP_FAILED) {
+ warn_on_large_pages_failure(lp_start, lp_bytes, errno);
+ // If the mmap above fails, the large pages region will be unmapped and we
+ // have regions before and after with small pages. Release these regions.
+ //
+ // | mapped | unmapped | mapped |
+ // ^ ^ ^ ^
+ // start lp_start lp_end end
+ //
+ ::munmap(start, lp_start - start);
+ ::munmap(lp_end, end - lp_end);
+ return NULL;
+ }
+
+ // Commit small-paged trailing area.
+ if (lp_end != end) {
+ result = ::mmap(lp_end, end - lp_end, prot,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,
+ -1, 0);
+ if (result == MAP_FAILED) {
+ ::munmap(start, lp_end - start);
+ return NULL;
+ }
+ }
+
+ return start;
+}
+
+char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes,
+ size_t alignment,
+ char* req_addr,
+ bool exec) {
+ assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages");
+ assert(is_aligned(req_addr, alignment), "Must be");
+ assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be");
+ assert(is_power_of_2(os::large_page_size()), "Must be");
+ assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes");
+
+ if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) {
+ return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec);
+ } else {
+ return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec);
+ }
+}
+
+char* os::reserve_memory_special(size_t bytes, size_t alignment,
+ char* req_addr, bool exec) {
+ assert(UseLargePages, "only for large pages");
+
+ char* addr;
+ if (UseSHM) {
+ addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec);
+ } else {
+ assert(UseHugeTLBFS, "must be");
+ addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec);
+ }
+
+ if (addr != NULL) {
+ if (UseNUMAInterleaving) {
+ numa_make_global(addr, bytes);
+ }
+
+ // The memory is committed
+ MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
+ }
+
+ return addr;
+}
+
+bool os::Linux::release_memory_special_shm(char* base, size_t bytes) {
+ // detaching the SHM segment will also delete it, see reserve_memory_special_shm()
+ return shmdt(base) == 0;
+}
+
+bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) {
+ return pd_release_memory(base, bytes);
+}
+
+bool os::release_memory_special(char* base, size_t bytes) {
+ bool res;
+ if (MemTracker::tracking_level() > NMT_minimal) {
+ Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
+ res = os::Linux::release_memory_special_impl(base, bytes);
+ if (res) {
+ tkr.record((address)base, bytes);
+ }
+
+ } else {
+ res = os::Linux::release_memory_special_impl(base, bytes);
+ }
+ return res;
+}
+
+bool os::Linux::release_memory_special_impl(char* base, size_t bytes) {
+ assert(UseLargePages, "only for large pages");
+ bool res;
+
+ if (UseSHM) {
+ res = os::Linux::release_memory_special_shm(base, bytes);
+ } else {
+ assert(UseHugeTLBFS, "must be");
+ res = os::Linux::release_memory_special_huge_tlbfs(base, bytes);
+ }
+ return res;
+}
+
+size_t os::large_page_size() {
+ return _large_page_size;
+}
+
+// With SysV SHM the entire memory region must be allocated as shared
+// memory.
+// HugeTLBFS allows application to commit large page memory on demand.
+// However, when committing memory with HugeTLBFS fails, the region
+// that was supposed to be committed will lose the old reservation
+// and allow other threads to steal that memory region. Because of this
+// behavior we can't commit HugeTLBFS memory.
+bool os::can_commit_large_page_memory() {
+ return UseTransparentHugePages;
+}
+
+bool os::can_execute_large_page_memory() {
+ return UseTransparentHugePages || UseHugeTLBFS;
+}
+
+// Reserve memory at an arbitrary address, only if that area is
+// available (and not reserved for something else).
+
+char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
+ const int max_tries = 10;
+ char* base[max_tries];
+ size_t size[max_tries];
+ const size_t gap = 0x000000;
+
+ // Assert only that the size is a multiple of the page size, since
+ // that's all that mmap requires, and since that's all we really know
+ // about at this low abstraction level. If we need higher alignment,
+ // we can either pass an alignment to this method or verify alignment
+ // in one of the methods further up the call chain. See bug 5044738.
+ assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
+
+ // Repeatedly allocate blocks until the block is allocated at the
+ // right spot.
+
+ // Linux mmap allows caller to pass an address as hint; give it a try first,
+ // if kernel honors the hint then we can return immediately.
+ char * addr = anon_mmap(requested_addr, bytes, false);
+ if (addr == requested_addr) {
+ return requested_addr;
+ }
+
+ if (addr != NULL) {
+ // mmap() is successful but it fails to reserve at the requested address
+ anon_munmap(addr, bytes);
+ }
+
+ int i;
+ for (i = 0; i < max_tries; ++i) {
+ base[i] = reserve_memory(bytes);
+
+ if (base[i] != NULL) {
+ // Is this the block we wanted?
+ if (base[i] == requested_addr) {
+ size[i] = bytes;
+ break;
+ }
+
+ // Does this overlap the block we wanted? Give back the overlapped
+ // parts and try again.
+
+ ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i];
+ if (top_overlap >= 0 && (size_t)top_overlap < bytes) {
+ unmap_memory(base[i], top_overlap);
+ base[i] += top_overlap;
+ size[i] = bytes - top_overlap;
+ } else {
+ ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr;
+ if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) {
+ unmap_memory(requested_addr, bottom_overlap);
+ size[i] = bytes - bottom_overlap;
+ } else {
+ size[i] = bytes;
+ }
+ }
+ }
+ }
+
+ // Give back the unused reserved pieces.
+
+ for (int j = 0; j < i; ++j) {
+ if (base[j] != NULL) {
+ unmap_memory(base[j], size[j]);
+ }
+ }
+
+ if (i < max_tries) {
+ return requested_addr;
+ } else {
+ return NULL;
+ }
+}
+
+size_t os::read(int fd, void *buf, unsigned int nBytes) {
+ return ::read(fd, buf, nBytes);
+}
+
+size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
+ return ::pread(fd, buf, nBytes, offset);
+}
+
+// Short sleep, direct OS call.
+//
+// Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee
+// sched_yield(2) will actually give up the CPU:
+//
+// * Alone on this pariticular CPU, keeps running.
+// * Before the introduction of "skip_buddy" with "compat_yield" disabled
+// (pre 2.6.39).
+//
+// So calling this with 0 is an alternative.
+//
+void os::naked_short_sleep(jlong ms) {
+ struct timespec req;
+
+ assert(ms < 1000, "Un-interruptable sleep, short time use only");
+ req.tv_sec = 0;
+ if (ms > 0) {
+ req.tv_nsec = (ms % 1000) * 1000000;
+ } else {
+ req.tv_nsec = 1;
+ }
+
+ nanosleep(&req, NULL);
+
+ return;
+}
+
+// Sleep forever; naked call to OS-specific sleep; use with CAUTION
+void os::infinite_sleep() {
+ while (true) { // sleep forever ...
+ ::sleep(100); // ... 100 seconds at a time
+ }
+}
+
+// Used to convert frequent JVM_Yield() to nops
+bool os::dont_yield() {
+ return DontYieldALot;
+}
+
+void os::naked_yield() {
+ sched_yield();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// thread priority support
+
+// Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
+// only supports dynamic priority, static priority must be zero. For real-time
+// applications, Linux supports SCHED_RR which allows static priority (1-99).
+// However, for large multi-threaded applications, SCHED_RR is not only slower
+// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
+// of 5 runs - Sep 2005).
+//
+// The following code actually changes the niceness of kernel-thread/LWP. It
+// has an assumption that setpriority() only modifies one kernel-thread/LWP,
+// not the entire user process, and user level threads are 1:1 mapped to kernel
+// threads. It has always been the case, but could change in the future. For
+// this reason, the code should not be used as default (ThreadPriorityPolicy=0).
+// It is only used when ThreadPriorityPolicy=1 and requires root privilege.
+
+int os::java_to_os_priority[CriticalPriority + 1] = {
+ 19, // 0 Entry should never be used
+
+ 4, // 1 MinPriority
+ 3, // 2
+ 2, // 3
+
+ 1, // 4
+ 0, // 5 NormPriority
+ -1, // 6
+
+ -2, // 7
+ -3, // 8
+ -4, // 9 NearMaxPriority
+
+ -5, // 10 MaxPriority
+
+ -5 // 11 CriticalPriority
+};
+
+static int prio_init() {
+ if (ThreadPriorityPolicy == 1) {
+ // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
+ // if effective uid is not root. Perhaps, a more elegant way of doing
+ // this is to test CAP_SYS_NICE capability, but that will require libcap.so
+ if (geteuid() != 0) {
+ if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
+ warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
+ }
+ ThreadPriorityPolicy = 0;
+ }
+ }
+ if (UseCriticalJavaThreadPriority) {
+ os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
+ }
+ return 0;
+}
+
+OSReturn os::set_native_priority(Thread* thread, int newpri) {
+ if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
+
+ int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
+ return (ret == 0) ? OS_OK : OS_ERR;
+}
+
+OSReturn os::get_native_priority(const Thread* const thread,
+ int *priority_ptr) {
+ if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
+ *priority_ptr = java_to_os_priority[NormPriority];
+ return OS_OK;
+ }
+
+ errno = 0;
+ *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
+ return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
+}
+
+// Hint to the underlying OS that a task switch would not be good.
+// Void return because it's a hint and can fail.
+void os::hint_no_preempt() {}
+
+////////////////////////////////////////////////////////////////////////////////
+// suspend/resume support
+
+// The low-level signal-based suspend/resume support is a remnant from the
+// old VM-suspension that used to be for java-suspension, safepoints etc,
+// within hotspot. Currently used by JFR's OSThreadSampler
+//
+// The remaining code is greatly simplified from the more general suspension
+// code that used to be used.
+//
+// The protocol is quite simple:
+// - suspend:
+// - sends a signal to the target thread
+// - polls the suspend state of the osthread using a yield loop
+// - target thread signal handler (SR_handler) sets suspend state
+// and blocks in sigsuspend until continued
+// - resume:
+// - sets target osthread state to continue
+// - sends signal to end the sigsuspend loop in the SR_handler
+//
+// Note that the SR_lock plays no role in this suspend/resume protocol,
+// but is checked for NULL in SR_handler as a thread termination indicator.
+// The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
+//
+// Note that resume_clear_context() and suspend_save_context() are needed
+// by SR_handler(), so that fetch_frame_from_ucontext() works,
+// which in part is used by:
+// - Forte Analyzer: AsyncGetCallTrace()
+// - StackBanging: get_frame_at_stack_banging_point()
+
+static void resume_clear_context(OSThread *osthread) {
+ osthread->set_ucontext(NULL);
+ osthread->set_siginfo(NULL);
+}
+
+static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo,
+ ucontext_t* context) {
+ osthread->set_ucontext(context);
+ osthread->set_siginfo(siginfo);
+}
+
+// Handler function invoked when a thread's execution is suspended or
+// resumed. We have to be careful that only async-safe functions are
+// called here (Note: most pthread functions are not async safe and
+// should be avoided.)
+//
+// Note: sigwait() is a more natural fit than sigsuspend() from an
+// interface point of view, but sigwait() prevents the signal hander
+// from being run. libpthread would get very confused by not having
+// its signal handlers run and prevents sigwait()'s use with the
+// mutex granting granting signal.
+//
+// Currently only ever called on the VMThread and JavaThreads (PC sampling)
+//
+static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
+ // Save and restore errno to avoid confusing native code with EINTR
+ // after sigsuspend.
+ int old_errno = errno;
+
+ Thread* thread = Thread::current_or_null_safe();
+ assert(thread != NULL, "Missing current thread in SR_handler");
+
+ // On some systems we have seen signal delivery get "stuck" until the signal
+ // mask is changed as part of thread termination. Check that the current thread
+ // has not already terminated (via SR_lock()) - else the following assertion
+ // will fail because the thread is no longer a JavaThread as the ~JavaThread
+ // destructor has completed.
+
+ if (thread->SR_lock() == NULL) {
+ return;
+ }
+
+ assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
+
+ OSThread* osthread = thread->osthread();
+
+ os::SuspendResume::State current = osthread->sr.state();
+ if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
+ suspend_save_context(osthread, siginfo, context);
+
+ // attempt to switch the state, we assume we had a SUSPEND_REQUEST
+ os::SuspendResume::State state = osthread->sr.suspended();
+ if (state == os::SuspendResume::SR_SUSPENDED) {
+ sigset_t suspend_set; // signals for sigsuspend()
+ sigemptyset(&suspend_set);
+ // get current set of blocked signals and unblock resume signal
+ pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
+ sigdelset(&suspend_set, SR_signum);
+
+ sr_semaphore.signal();
+ // wait here until we are resumed
+ while (1) {
+ sigsuspend(&suspend_set);
+
+ os::SuspendResume::State result = osthread->sr.running();
+ if (result == os::SuspendResume::SR_RUNNING) {
+ sr_semaphore.signal();
+ break;
+ }
+ }
+
+ } else if (state == os::SuspendResume::SR_RUNNING) {
+ // request was cancelled, continue
+ } else {
+ ShouldNotReachHere();
+ }
+
+ resume_clear_context(osthread);
+ } else if (current == os::SuspendResume::SR_RUNNING) {
+ // request was cancelled, continue
+ } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
+ // ignore
+ } else {
+ // ignore
+ }
+
+ errno = old_errno;
+}
+
+static int SR_initialize() {
+ struct sigaction act;
+ char *s;
+
+ // Get signal number to use for suspend/resume
+ if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
+ int sig = ::strtol(s, 0, 10);
+ if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
+ sig < NSIG) { // Must be legal signal and fit into sigflags[].
+ SR_signum = sig;
+ } else {
+ warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
+ sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
+ }
+ }
+
+ assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
+ "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
+
+ sigemptyset(&SR_sigset);
+ sigaddset(&SR_sigset, SR_signum);
+
+ // Set up signal handler for suspend/resume
+ act.sa_flags = SA_RESTART|SA_SIGINFO;
+ act.sa_handler = (void (*)(int)) SR_handler;
+
+ // SR_signum is blocked by default.
+ // 4528190 - We also need to block pthread restart signal (32 on all
+ // supported Linux platforms). Note that LinuxThreads need to block
+ // this signal for all threads to work properly. So we don't have
+ // to use hard-coded signal number when setting up the mask.
+ pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
+
+ if (sigaction(SR_signum, &act, 0) == -1) {
+ return -1;
+ }
+
+ // Save signal flag
+ os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
+ return 0;
+}
+
+static int sr_notify(OSThread* osthread) {
+ int status = pthread_kill(osthread->pthread_id(), SR_signum);
+ assert_status(status == 0, status, "pthread_kill");
+ return status;
+}
+
+// "Randomly" selected value for how long we want to spin
+// before bailing out on suspending a thread, also how often
+// we send a signal to a thread we want to resume
+static const int RANDOMLY_LARGE_INTEGER = 1000000;
+static const int RANDOMLY_LARGE_INTEGER2 = 100;
+
+// returns true on success and false on error - really an error is fatal
+// but this seems the normal response to library errors
+static bool do_suspend(OSThread* osthread) {
+ assert(osthread->sr.is_running(), "thread should be running");
+ assert(!sr_semaphore.trywait(), "semaphore has invalid state");
+
+ // mark as suspended and send signal
+ if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
+ // failed to switch, state wasn't running?
+ ShouldNotReachHere();
+ return false;
+ }
+
+ if (sr_notify(osthread) != 0) {
+ ShouldNotReachHere();
+ }
+
+ // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
+ while (true) {
+ if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
+ break;
+ } else {
+ // timeout
+ os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
+ if (cancelled == os::SuspendResume::SR_RUNNING) {
+ return false;
+ } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
+ // make sure that we consume the signal on the semaphore as well
+ sr_semaphore.wait();
+ break;
+ } else {
+ ShouldNotReachHere();
+ return false;
+ }
+ }
+ }
+
+ guarantee(osthread->sr.is_suspended(), "Must be suspended");
+ return true;
+}
+
+static void do_resume(OSThread* osthread) {
+ assert(osthread->sr.is_suspended(), "thread should be suspended");
+ assert(!sr_semaphore.trywait(), "invalid semaphore state");
+
+ if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
+ // failed to switch to WAKEUP_REQUEST
+ ShouldNotReachHere();
+ return;
+ }
+
+ while (true) {
+ if (sr_notify(osthread) == 0) {
+ if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
+ if (osthread->sr.is_running()) {
+ return;
+ }
+ }
+ } else {
+ ShouldNotReachHere();
+ }
+ }
+
+ guarantee(osthread->sr.is_running(), "Must be running!");
+}
+
+///////////////////////////////////////////////////////////////////////////////////
+// signal handling (except suspend/resume)
+
+// This routine may be used by user applications as a "hook" to catch signals.
+// The user-defined signal handler must pass unrecognized signals to this
+// routine, and if it returns true (non-zero), then the signal handler must
+// return immediately. If the flag "abort_if_unrecognized" is true, then this
+// routine will never retun false (zero), but instead will execute a VM panic
+// routine kill the process.
+//
+// If this routine returns false, it is OK to call it again. This allows
+// the user-defined signal handler to perform checks either before or after
+// the VM performs its own checks. Naturally, the user code would be making
+// a serious error if it tried to handle an exception (such as a null check
+// or breakpoint) that the VM was generating for its own correct operation.
+//
+// This routine may recognize any of the following kinds of signals:
+// SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
+// It should be consulted by handlers for any of those signals.
+//
+// The caller of this routine must pass in the three arguments supplied
+// to the function referred to in the "sa_sigaction" (not the "sa_handler")
+// field of the structure passed to sigaction(). This routine assumes that
+// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
+//
+// Note that the VM will print warnings if it detects conflicting signal
+// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
+//
+extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo,
+ siginfo_t* siginfo,
+ void* ucontext,
+ int abort_if_unrecognized);
+
+void signalHandler(int sig, siginfo_t* info, void* uc) {
+ assert(info != NULL && uc != NULL, "it must be old kernel");
+ int orig_errno = errno; // Preserve errno value over signal handler.
+ JVM_handle_linux_signal(sig, info, uc, true);
+ errno = orig_errno;
+}
+
+
+// This boolean allows users to forward their own non-matching signals
+// to JVM_handle_linux_signal, harmlessly.
+bool os::Linux::signal_handlers_are_installed = false;
+
+// For signal-chaining
+struct sigaction sigact[NSIG];
+uint64_t sigs = 0;
+#if (64 < NSIG-1)
+#error "Not all signals can be encoded in sigs. Adapt its type!"
+#endif
+bool os::Linux::libjsig_is_loaded = false;
+typedef struct sigaction *(*get_signal_t)(int);
+get_signal_t os::Linux::get_signal_action = NULL;
+
+struct sigaction* os::Linux::get_chained_signal_action(int sig) {
+ struct sigaction *actp = NULL;
+
+ if (libjsig_is_loaded) {
+ // Retrieve the old signal handler from libjsig
+ actp = (*get_signal_action)(sig);
+ }
+ if (actp == NULL) {
+ // Retrieve the preinstalled signal handler from jvm
+ actp = get_preinstalled_handler(sig);
+ }
+
+ return actp;
+}
+
+static bool call_chained_handler(struct sigaction *actp, int sig,
+ siginfo_t *siginfo, void *context) {
+ // Call the old signal handler
+ if (actp->sa_handler == SIG_DFL) {
+ // It's more reasonable to let jvm treat it as an unexpected exception
+ // instead of taking the default action.
+ return false;
+ } else if (actp->sa_handler != SIG_IGN) {
+ if ((actp->sa_flags & SA_NODEFER) == 0) {
+ // automaticlly block the signal
+ sigaddset(&(actp->sa_mask), sig);
+ }
+
+ sa_handler_t hand = NULL;
+ sa_sigaction_t sa = NULL;
+ bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
+ // retrieve the chained handler
+ if (siginfo_flag_set) {
+ sa = actp->sa_sigaction;
+ } else {
+ hand = actp->sa_handler;
+ }
+
+ if ((actp->sa_flags & SA_RESETHAND) != 0) {
+ actp->sa_handler = SIG_DFL;
+ }
+
+ // try to honor the signal mask
+ sigset_t oset;
+ sigemptyset(&oset);
+ pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
+
+ // call into the chained handler
+ if (siginfo_flag_set) {
+ (*sa)(sig, siginfo, context);
+ } else {
+ (*hand)(sig);
+ }
+
+ // restore the signal mask
+ pthread_sigmask(SIG_SETMASK, &oset, NULL);
+ }
+ // Tell jvm's signal handler the signal is taken care of.
+ return true;
+}
+
+bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
+ bool chained = false;
+ // signal-chaining
+ if (UseSignalChaining) {
+ struct sigaction *actp = get_chained_signal_action(sig);
+ if (actp != NULL) {
+ chained = call_chained_handler(actp, sig, siginfo, context);
+ }
+ }
+ return chained;
+}
+
+struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
+ if ((((uint64_t)1 << (sig-1)) & sigs) != 0) {
+ return &sigact[sig];
+ }
+ return NULL;
+}
+
+void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
+ assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+ sigact[sig] = oldAct;
+ sigs |= (uint64_t)1 << (sig-1);
+}
+
+// for diagnostic
+int sigflags[NSIG];
+
+int os::Linux::get_our_sigflags(int sig) {
+ assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+ return sigflags[sig];
+}
+
+void os::Linux::set_our_sigflags(int sig, int flags) {
+ assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+ if (sig > 0 && sig < NSIG) {
+ sigflags[sig] = flags;
+ }
+}
+
+void os::Linux::set_signal_handler(int sig, bool set_installed) {
+ // Check for overwrite.
+ struct sigaction oldAct;
+ sigaction(sig, (struct sigaction*)NULL, &oldAct);
+
+ void* oldhand = oldAct.sa_sigaction
+ ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
+ : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
+ if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
+ oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
+ oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
+ if (AllowUserSignalHandlers || !set_installed) {
+ // Do not overwrite; user takes responsibility to forward to us.
+ return;
+ } else if (UseSignalChaining) {
+ // save the old handler in jvm
+ save_preinstalled_handler(sig, oldAct);
+ // libjsig also interposes the sigaction() call below and saves the
+ // old sigaction on it own.
+ } else {
+ fatal("Encountered unexpected pre-existing sigaction handler "
+ "%#lx for signal %d.", (long)oldhand, sig);
+ }
+ }
+
+ struct sigaction sigAct;
+ sigfillset(&(sigAct.sa_mask));
+ sigAct.sa_handler = SIG_DFL;
+ if (!set_installed) {
+ sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
+ } else {
+ sigAct.sa_sigaction = signalHandler;
+ sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
+ }
+ // Save flags, which are set by ours
+ assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+ sigflags[sig] = sigAct.sa_flags;
+
+ int ret = sigaction(sig, &sigAct, &oldAct);
+ assert(ret == 0, "check");
+
+ void* oldhand2 = oldAct.sa_sigaction
+ ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
+ : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
+ assert(oldhand2 == oldhand, "no concurrent signal handler installation");
+}
+
+// install signal handlers for signals that HotSpot needs to
+// handle in order to support Java-level exception handling.
+
+void os::Linux::install_signal_handlers() {
+ if (!signal_handlers_are_installed) {
+ signal_handlers_are_installed = true;
+
+ // signal-chaining
+ typedef void (*signal_setting_t)();
+ signal_setting_t begin_signal_setting = NULL;
+ signal_setting_t end_signal_setting = NULL;
+ begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
+ dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
+ if (begin_signal_setting != NULL) {
+ end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
+ dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
+ get_signal_action = CAST_TO_FN_PTR(get_signal_t,
+ dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
+ libjsig_is_loaded = true;
+ assert(UseSignalChaining, "should enable signal-chaining");
+ }
+ if (libjsig_is_loaded) {
+ // Tell libjsig jvm is setting signal handlers
+ (*begin_signal_setting)();
+ }
+
+ set_signal_handler(SIGSEGV, true);
+ set_signal_handler(SIGPIPE, true);
+ set_signal_handler(SIGBUS, true);
+ set_signal_handler(SIGILL, true);
+ set_signal_handler(SIGFPE, true);
+#if defined(PPC64)
+ set_signal_handler(SIGTRAP, true);
+#endif
+ set_signal_handler(SIGXFSZ, true);
+
+ if (libjsig_is_loaded) {
+ // Tell libjsig jvm finishes setting signal handlers
+ (*end_signal_setting)();
+ }
+
+ // We don't activate signal checker if libjsig is in place, we trust ourselves
+ // and if UserSignalHandler is installed all bets are off.
+ // Log that signal checking is off only if -verbose:jni is specified.
+ if (CheckJNICalls) {
+ if (libjsig_is_loaded) {
+ if (PrintJNIResolving) {
+ tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
+ }
+ check_signals = false;
+ }
+ if (AllowUserSignalHandlers) {
+ if (PrintJNIResolving) {
+ tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
+ }
+ check_signals = false;
+ }
+ }
+ }
+}
+
+// This is the fastest way to get thread cpu time on Linux.
+// Returns cpu time (user+sys) for any thread, not only for current.
+// POSIX compliant clocks are implemented in the kernels 2.6.16+.
+// It might work on 2.6.10+ with a special kernel/glibc patch.
+// For reference, please, see IEEE Std 1003.1-2004:
+// http://www.unix.org/single_unix_specification
+
+jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
+ struct timespec tp;
+ int rc = os::Linux::clock_gettime(clockid, &tp);
+ assert(rc == 0, "clock_gettime is expected to return 0 code");
+
+ return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec;
+}
+
+void os::Linux::initialize_os_info() {
+ assert(_os_version == 0, "OS info already initialized");
+
+ struct utsname _uname;
+
+ uint32_t major;
+ uint32_t minor;
+ uint32_t fix;
+
+ int rc;
+
+ // Kernel version is unknown if
+ // verification below fails.
+ _os_version = 0x01000000;
+
+ rc = uname(&_uname);
+ if (rc != -1) {
+
+ rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix);
+ if (rc == 3) {
+
+ if (major < 256 && minor < 256 && fix < 256) {
+ // Kernel version format is as expected,
+ // set it overriding unknown state.
+ _os_version = (major << 16) |
+ (minor << 8 ) |
+ (fix << 0 ) ;
+ }
+ }
+ }
+}
+
+uint32_t os::Linux::os_version() {
+ assert(_os_version != 0, "not initialized");
+ return _os_version & 0x00FFFFFF;
+}
+
+bool os::Linux::os_version_is_known() {
+ assert(_os_version != 0, "not initialized");
+ return _os_version & 0x01000000 ? false : true;
+}
+
+/////
+// glibc on Linux platform uses non-documented flag
+// to indicate, that some special sort of signal
+// trampoline is used.
+// We will never set this flag, and we should
+// ignore this flag in our diagnostic
+#ifdef SIGNIFICANT_SIGNAL_MASK
+ #undef SIGNIFICANT_SIGNAL_MASK
+#endif
+#define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
+
+static const char* get_signal_handler_name(address handler,
+ char* buf, int buflen) {
+ int offset = 0;
+ bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
+ if (found) {
+ // skip directory names
+ const char *p1, *p2;
+ p1 = buf;
+ size_t len = strlen(os::file_separator());
+ while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
+ jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
+ } else {
+ jio_snprintf(buf, buflen, PTR_FORMAT, handler);
+ }
+ return buf;
+}
+
+static void print_signal_handler(outputStream* st, int sig,
+ char* buf, size_t buflen) {
+ struct sigaction sa;
+
+ sigaction(sig, NULL, &sa);
+
+ // See comment for SIGNIFICANT_SIGNAL_MASK define
+ sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
+
+ st->print("%s: ", os::exception_name(sig, buf, buflen));
+
+ address handler = (sa.sa_flags & SA_SIGINFO)
+ ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
+ : CAST_FROM_FN_PTR(address, sa.sa_handler);
+
+ if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
+ st->print("SIG_DFL");
+ } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
+ st->print("SIG_IGN");
+ } else {
+ st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
+ }
+
+ st->print(", sa_mask[0]=");
+ os::Posix::print_signal_set_short(st, &sa.sa_mask);
+
+ address rh = VMError::get_resetted_sighandler(sig);
+ // May be, handler was resetted by VMError?
+ if (rh != NULL) {
+ handler = rh;
+ sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
+ }
+
+ st->print(", sa_flags=");
+ os::Posix::print_sa_flags(st, sa.sa_flags);
+
+ // Check: is it our handler?
+ if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
+ handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
+ // It is our signal handler
+ // check for flags, reset system-used one!
+ if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
+ st->print(
+ ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
+ os::Linux::get_our_sigflags(sig));
+ }
+ }
+ st->cr();
+}
+
+
+#define DO_SIGNAL_CHECK(sig) \
+ do { \
+ if (!sigismember(&check_signal_done, sig)) { \
+ os::Linux::check_signal_handler(sig); \
+ } \
+ } while (0)
+
+// This method is a periodic task to check for misbehaving JNI applications
+// under CheckJNI, we can add any periodic checks here
+
+void os::run_periodic_checks() {
+ if (check_signals == false) return;
+
+ // SEGV and BUS if overridden could potentially prevent
+ // generation of hs*.log in the event of a crash, debugging
+ // such a case can be very challenging, so we absolutely
+ // check the following for a good measure:
+ DO_SIGNAL_CHECK(SIGSEGV);
+ DO_SIGNAL_CHECK(SIGILL);
+ DO_SIGNAL_CHECK(SIGFPE);
+ DO_SIGNAL_CHECK(SIGBUS);
+ DO_SIGNAL_CHECK(SIGPIPE);
+ DO_SIGNAL_CHECK(SIGXFSZ);
+#if defined(PPC64)
+ DO_SIGNAL_CHECK(SIGTRAP);
+#endif
+
+ // ReduceSignalUsage allows the user to override these handlers
+ // see comments at the very top and jvm_solaris.h
+ if (!ReduceSignalUsage) {
+ DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
+ DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
+ DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
+ DO_SIGNAL_CHECK(BREAK_SIGNAL);
+ }
+
+ DO_SIGNAL_CHECK(SR_signum);
+}
+
+typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
+
+static os_sigaction_t os_sigaction = NULL;
+
+void os::Linux::check_signal_handler(int sig) {
+ char buf[O_BUFLEN];
+ address jvmHandler = NULL;
+
+
+ struct sigaction act;
+ if (os_sigaction == NULL) {
+ // only trust the default sigaction, in case it has been interposed
+ os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
+ if (os_sigaction == NULL) return;
+ }
+
+ os_sigaction(sig, (struct sigaction*)NULL, &act);
+
+
+ act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
+
+ address thisHandler = (act.sa_flags & SA_SIGINFO)
+ ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
+ : CAST_FROM_FN_PTR(address, act.sa_handler);
+
+
+ switch (sig) {
+ case SIGSEGV:
+ case SIGBUS:
+ case SIGFPE:
+ case SIGPIPE:
+ case SIGILL:
+ case SIGXFSZ:
+ jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
+ break;
+
+ case SHUTDOWN1_SIGNAL:
+ case SHUTDOWN2_SIGNAL:
+ case SHUTDOWN3_SIGNAL:
+ case BREAK_SIGNAL:
+ jvmHandler = (address)user_handler();
+ break;
+
+ default:
+ if (sig == SR_signum) {
+ jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
+ } else {
+ return;
+ }
+ break;
+ }
+
+ if (thisHandler != jvmHandler) {
+ tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
+ tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
+ tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
+ // No need to check this sig any longer
+ sigaddset(&check_signal_done, sig);
+ // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
+ if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
+ tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
+ exception_name(sig, buf, O_BUFLEN));
+ }
+ } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
+ tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
+ tty->print("expected:");
+ os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig));
+ tty->cr();
+ tty->print(" found:");
+ os::Posix::print_sa_flags(tty, act.sa_flags);
+ tty->cr();
+ // No need to check this sig any longer
+ sigaddset(&check_signal_done, sig);
+ }
+
+ // Dump all the signal
+ if (sigismember(&check_signal_done, sig)) {
+ print_signal_handlers(tty, buf, O_BUFLEN);
+ }
+}
+
+extern void report_error(char* file_name, int line_no, char* title,
+ char* format, ...);
+
+// this is called _before_ the most of global arguments have been parsed
+void os::init(void) {
+ char dummy; // used to get a guess on initial stack address
+// first_hrtime = gethrtime();
+
+ clock_tics_per_sec = sysconf(_SC_CLK_TCK);
+
+ init_random(1234567);
+
+ ThreadCritical::initialize();
+
+ Linux::set_page_size(sysconf(_SC_PAGESIZE));
+ if (Linux::page_size() == -1) {
+ fatal("os_linux.cpp: os::init: sysconf failed (%s)",
+ os::strerror(errno));
+ }
+ init_page_sizes((size_t) Linux::page_size());
+
+ Linux::initialize_system_info();
+
+ Linux::initialize_os_info();
+
+ // main_thread points to the aboriginal thread
+ Linux::_main_thread = pthread_self();
+
+ Linux::clock_init();
+ initial_time_count = javaTimeNanos();
+
+ // retrieve entry point for pthread_setname_np
+ Linux::_pthread_setname_np =
+ (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np");
+
+ os::Posix::init();
+}
+
+// To install functions for atexit system call
+extern "C" {
+ static void perfMemory_exit_helper() {
+ perfMemory_exit();
+ }
+}
+
+// this is called _after_ the global arguments have been parsed
+jint os::init_2(void) {
+
+ os::Posix::init_2();
+
+ Linux::fast_thread_clock_init();
+
+ // Allocate a single page and mark it as readable for safepoint polling
+ address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
+
+ os::set_polling_page(polling_page);
+ log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
+
+ if (!UseMembar) {
+ address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
+ os::set_memory_serialize_page(mem_serialize_page);
+ log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
+ }
+
+ // initialize suspend/resume support - must do this before signal_sets_init()
+ if (SR_initialize() != 0) {
+ perror("SR_initialize failed");
+ return JNI_ERR;
+ }
+
+ Linux::signal_sets_init();
+ Linux::install_signal_handlers();
+
+ // Check and sets minimum stack sizes against command line options
+ if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
+ return JNI_ERR;
+ }
+ Linux::capture_initial_stack(JavaThread::stack_size_at_create());
+
+#if defined(IA32)
+ workaround_expand_exec_shield_cs_limit();
+#endif
+
+ Linux::libpthread_init();
+ Linux::sched_getcpu_init();
+ log_info(os)("HotSpot is running with %s, %s",
+ Linux::glibc_version(), Linux::libpthread_version());
+
+ if (UseNUMA) {
+ if (!Linux::libnuma_init()) {
+ UseNUMA = false;
+ } else {
+ if ((Linux::numa_max_node() < 1)) {
+ // There's only one node(they start from 0), disable NUMA.
+ UseNUMA = false;
+ }
+ }
+ // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way
+ // we can make the adaptive lgrp chunk resizing work. If the user specified
+ // both UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn and
+ // disable adaptive resizing.
+ if (UseNUMA && UseLargePages && !can_commit_large_page_memory()) {
+ if (FLAG_IS_DEFAULT(UseNUMA)) {
+ UseNUMA = false;
+ } else {
+ if (FLAG_IS_DEFAULT(UseLargePages) &&
+ FLAG_IS_DEFAULT(UseSHM) &&
+ FLAG_IS_DEFAULT(UseHugeTLBFS)) {
+ UseLargePages = false;
+ } else if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) {
+ warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)");
+ UseAdaptiveSizePolicy = false;
+ UseAdaptiveNUMAChunkSizing = false;
+ }
+ }
+ }
+ if (!UseNUMA && ForceNUMA) {
+ UseNUMA = true;
+ }
+ }
+
+ if (MaxFDLimit) {
+ // set the number of file descriptors to max. print out error
+ // if getrlimit/setrlimit fails but continue regardless.
+ struct rlimit nbr_files;
+ int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
+ if (status != 0) {
+ log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
+ } else {
+ nbr_files.rlim_cur = nbr_files.rlim_max;
+ status = setrlimit(RLIMIT_NOFILE, &nbr_files);
+ if (status != 0) {
+ log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
+ }
+ }
+ }
+
+ // Initialize lock used to serialize thread creation (see os::create_thread)
+ Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
+
+ // at-exit methods are called in the reverse order of their registration.
+ // atexit functions are called on return from main or as a result of a
+ // call to exit(3C). There can be only 32 of these functions registered
+ // and atexit() does not set errno.
+
+ if (PerfAllowAtExitRegistration) {
+ // only register atexit functions if PerfAllowAtExitRegistration is set.
+ // atexit functions can be delayed until process exit time, which
+ // can be problematic for embedded VM situations. Embedded VMs should
+ // call DestroyJavaVM() to assure that VM resources are released.
+
+ // note: perfMemory_exit_helper atexit function may be removed in
+ // the future if the appropriate cleanup code can be added to the
+ // VM_Exit VMOperation's doit method.
+ if (atexit(perfMemory_exit_helper) != 0) {
+ warning("os::init_2 atexit(perfMemory_exit_helper) failed");
+ }
+ }
+
+ // initialize thread priority policy
+ prio_init();
+
+ return JNI_OK;
+}
+
+// Mark the polling page as unreadable
+void os::make_polling_page_unreadable(void) {
+ if (!guard_memory((char*)_polling_page, Linux::page_size())) {
+ fatal("Could not disable polling page");
+ }
+}
+
+// Mark the polling page as readable
+void os::make_polling_page_readable(void) {
+ if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) {
+ fatal("Could not enable polling page");
+ }
+}
+
+// older glibc versions don't have this macro (which expands to
+// an optimized bit-counting function) so we have to roll our own
+#ifndef CPU_COUNT
+
+static int _cpu_count(const cpu_set_t* cpus) {
+ int count = 0;
+ // only look up to the number of configured processors
+ for (int i = 0; i < os::processor_count(); i++) {
+ if (CPU_ISSET(i, cpus)) {
+ count++;
+ }
+ }
+ return count;
+}
+
+#define CPU_COUNT(cpus) _cpu_count(cpus)
+
+#endif // CPU_COUNT
+
+// Get the current number of available processors for this process.
+// This value can change at any time during a process's lifetime.
+// sched_getaffinity gives an accurate answer as it accounts for cpusets.
+// If it appears there may be more than 1024 processors then we do a
+// dynamic check - see 6515172 for details.
+// If anything goes wrong we fallback to returning the number of online
+// processors - which can be greater than the number available to the process.
+int os::active_processor_count() {
+ cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors
+ cpu_set_t* cpus_p = &cpus;
+ int cpus_size = sizeof(cpu_set_t);
+
+ int configured_cpus = processor_count(); // upper bound on available cpus
+ int cpu_count = 0;
+
+// old build platforms may not support dynamic cpu sets
+#ifdef CPU_ALLOC
+
+ // To enable easy testing of the dynamic path on different platforms we
+ // introduce a diagnostic flag: UseCpuAllocPath
+ if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) {
+ // kernel may use a mask bigger than cpu_set_t
+ log_trace(os)("active_processor_count: using dynamic path %s"
+ "- configured processors: %d",
+ UseCpuAllocPath ? "(forced) " : "",
+ configured_cpus);
+ cpus_p = CPU_ALLOC(configured_cpus);
+ if (cpus_p != NULL) {
+ cpus_size = CPU_ALLOC_SIZE(configured_cpus);
+ // zero it just to be safe
+ CPU_ZERO_S(cpus_size, cpus_p);
+ }
+ else {
+ // failed to allocate so fallback to online cpus
+ int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
+ log_trace(os)("active_processor_count: "
+ "CPU_ALLOC failed (%s) - using "
+ "online processor count: %d",
+ os::strerror(errno), online_cpus);
+ return online_cpus;
+ }
+ }
+ else {
+ log_trace(os)("active_processor_count: using static path - configured processors: %d",
+ configured_cpus);
+ }
+#else // CPU_ALLOC
+// these stubs won't be executed
+#define CPU_COUNT_S(size, cpus) -1
+#define CPU_FREE(cpus)
+
+ log_trace(os)("active_processor_count: only static path available - configured processors: %d",
+ configured_cpus);
+#endif // CPU_ALLOC
+
+ // pid 0 means the current thread - which we have to assume represents the process
+ if (sched_getaffinity(0, cpus_size, cpus_p) == 0) {
+ if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
+ cpu_count = CPU_COUNT_S(cpus_size, cpus_p);
+ }
+ else {
+ cpu_count = CPU_COUNT(cpus_p);
+ }
+ log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count);
+ }
+ else {
+ cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN);
+ warning("sched_getaffinity failed (%s)- using online processor count (%d) "
+ "which may exceed available processors", os::strerror(errno), cpu_count);
+ }
+
+ if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used
+ CPU_FREE(cpus_p);
+ }
+
+ assert(cpu_count > 0 && cpu_count <= processor_count(), "sanity check");
+ return cpu_count;
+}
+
+void os::set_native_thread_name(const char *name) {
+ if (Linux::_pthread_setname_np) {
+ char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
+ snprintf(buf, sizeof(buf), "%s", name);
+ buf[sizeof(buf) - 1] = '\0';
+ const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
+ // ERANGE should not happen; all other errors should just be ignored.
+ assert(rc != ERANGE, "pthread_setname_np failed");
+ }
+}
+
+bool os::distribute_processes(uint length, uint* distribution) {
+ // Not yet implemented.
+ return false;
+}
+
+bool os::bind_to_processor(uint processor_id) {
+ // Not yet implemented.
+ return false;
+}
+
+///
+
+void os::SuspendedThreadTask::internal_do_task() {
+ if (do_suspend(_thread->osthread())) {
+ SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
+ do_task(context);
+ do_resume(_thread->osthread());
+ }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// debug support
+
+bool os::find(address addr, outputStream* st) {
+ Dl_info dlinfo;
+ memset(&dlinfo, 0, sizeof(dlinfo));
+ if (dladdr(addr, &dlinfo) != 0) {
+ st->print(PTR_FORMAT ": ", p2i(addr));
+ if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
+ st->print("%s+" PTR_FORMAT, dlinfo.dli_sname,
+ p2i(addr) - p2i(dlinfo.dli_saddr));
+ } else if (dlinfo.dli_fbase != NULL) {
+ st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase));
+ } else {
+ st->print("<absolute address>");
+ }
+ if (dlinfo.dli_fname != NULL) {
+ st->print(" in %s", dlinfo.dli_fname);
+ }
+ if (dlinfo.dli_fbase != NULL) {
+ st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase));
+ }
+ st->cr();
+
+ if (Verbose) {
+ // decode some bytes around the PC
+ address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
+ address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
+ address lowest = (address) dlinfo.dli_sname;
+ if (!lowest) lowest = (address) dlinfo.dli_fbase;
+ if (begin < lowest) begin = lowest;
+ Dl_info dlinfo2;
+ if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
+ && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
+ end = (address) dlinfo2.dli_saddr;
+ }
+ Disassembler::decode(begin, end, st);
+ }
+ return true;
+ }
+ return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// misc
+
+// This does not do anything on Linux. This is basically a hook for being
+// able to use structured exception handling (thread-local exception filters)
+// on, e.g., Win32.
+void
+os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
+ JavaCallArguments* args, Thread* thread) {
+ f(value, method, args, thread);
+}
+
+void os::print_statistics() {
+}
+
+bool os::message_box(const char* title, const char* message) {
+ int i;
+ fdStream err(defaultStream::error_fd());
+ for (i = 0; i < 78; i++) err.print_raw("=");
+ err.cr();
+ err.print_raw_cr(title);
+ for (i = 0; i < 78; i++) err.print_raw("-");
+ err.cr();
+ err.print_raw_cr(message);
+ for (i = 0; i < 78; i++) err.print_raw("=");
+ err.cr();
+
+ char buf[16];
+ // Prevent process from exiting upon "read error" without consuming all CPU
+ while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
+
+ return buf[0] == 'y' || buf[0] == 'Y';
+}
+
+int os::stat(const char *path, struct stat *sbuf) {
+ char pathbuf[MAX_PATH];
+ if (strlen(path) > MAX_PATH - 1) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+ os::native_path(strcpy(pathbuf, path));
+ return ::stat(pathbuf, sbuf);
+}
+
+// Is a (classpath) directory empty?
+bool os::dir_is_empty(const char* path) {
+ DIR *dir = NULL;
+ struct dirent *ptr;
+
+ dir = opendir(path);
+ if (dir == NULL) return true;
+
+ // Scan the directory
+ bool result = true;
+ char buf[sizeof(struct dirent) + MAX_PATH];
+ while (result && (ptr = ::readdir(dir)) != NULL) {
+ if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
+ result = false;
+ }
+ }
+ closedir(dir);
+ return result;
+}
+
+// This code originates from JDK's sysOpen and open64_w
+// from src/solaris/hpi/src/system_md.c
+
+int os::open(const char *path, int oflag, int mode) {
+ if (strlen(path) > MAX_PATH - 1) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+
+ // All file descriptors that are opened in the Java process and not
+ // specifically destined for a subprocess should have the close-on-exec
+ // flag set. If we don't set it, then careless 3rd party native code
+ // might fork and exec without closing all appropriate file descriptors
+ // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in
+ // turn might:
+ //
+ // - cause end-of-file to fail to be detected on some file
+ // descriptors, resulting in mysterious hangs, or
+ //
+ // - might cause an fopen in the subprocess to fail on a system
+ // suffering from bug 1085341.
+ //
+ // (Yes, the default setting of the close-on-exec flag is a Unix
+ // design flaw)
+ //
+ // See:
+ // 1085341: 32-bit stdio routines should support file descriptors >255
+ // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
+ // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
+ //
+ // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open().
+ // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor
+ // because it saves a system call and removes a small window where the flag
+ // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored
+ // and we fall back to using FD_CLOEXEC (see below).
+#ifdef O_CLOEXEC
+ oflag |= O_CLOEXEC;
+#endif
+
+ int fd = ::open64(path, oflag, mode);
+ if (fd == -1) return -1;
+
+ //If the open succeeded, the file might still be a directory
+ {
+ struct stat64 buf64;
+ int ret = ::fstat64(fd, &buf64);
+ int st_mode = buf64.st_mode;
+
+ if (ret != -1) {
+ if ((st_mode & S_IFMT) == S_IFDIR) {
+ errno = EISDIR;
+ ::close(fd);
+ return -1;
+ }
+ } else {
+ ::close(fd);
+ return -1;
+ }
+ }
+
+#ifdef FD_CLOEXEC
+ // Validate that the use of the O_CLOEXEC flag on open above worked.
+ // With recent kernels, we will perform this check exactly once.
+ static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
+ if (!O_CLOEXEC_is_known_to_work) {
+ int flags = ::fcntl(fd, F_GETFD);
+ if (flags != -1) {
+ if ((flags & FD_CLOEXEC) != 0)
+ O_CLOEXEC_is_known_to_work = 1;
+ else
+ ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+ }
+ }
+#endif
+
+ return fd;
+}
+
+
+// create binary file, rewriting existing file if required
+int os::create_binary_file(const char* path, bool rewrite_existing) {
+ int oflags = O_WRONLY | O_CREAT;
+ if (!rewrite_existing) {
+ oflags |= O_EXCL;
+ }
+ return ::open64(path, oflags, S_IREAD | S_IWRITE);
+}
+
+// return current position of file pointer
+jlong os::current_file_offset(int fd) {
+ return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
+}
+
+// move file pointer to the specified offset
+jlong os::seek_to_file_offset(int fd, jlong offset) {
+ return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
+}
+
+// This code originates from JDK's sysAvailable
+// from src/solaris/hpi/src/native_threads/src/sys_api_td.c
+
+int os::available(int fd, jlong *bytes) {
+ jlong cur, end;
+ int mode;
+ struct stat64 buf64;
+
+ if (::fstat64(fd, &buf64) >= 0) {
+ mode = buf64.st_mode;
+ if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
+ int n;
+ if (::ioctl(fd, FIONREAD, &n) >= 0) {
+ *bytes = n;
+ return 1;
+ }
+ }
+ }
+ if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) {
+ return 0;
+ } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) {
+ return 0;
+ } else if (::lseek64(fd, cur, SEEK_SET) == -1) {
+ return 0;
+ }
+ *bytes = end - cur;
+ return 1;
+}
+
+// Map a block of memory.
+char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
+ char *addr, size_t bytes, bool read_only,
+ bool allow_exec) {
+ int prot;
+ int flags = MAP_PRIVATE;
+
+ if (read_only) {
+ prot = PROT_READ;
+ } else {
+ prot = PROT_READ | PROT_WRITE;
+ }
+
+ if (allow_exec) {
+ prot |= PROT_EXEC;
+ }
+
+ if (addr != NULL) {
+ flags |= MAP_FIXED;
+ }
+
+ char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
+ fd, file_offset);
+ if (mapped_address == MAP_FAILED) {
+ return NULL;
+ }
+ return mapped_address;
+}
+
+
+// Remap a block of memory.
+char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
+ char *addr, size_t bytes, bool read_only,
+ bool allow_exec) {
+ // same as map_memory() on this OS
+ return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
+ allow_exec);
+}
+
+
+// Unmap a block of memory.
+bool os::pd_unmap_memory(char* addr, size_t bytes) {
+ return munmap(addr, bytes) == 0;
+}
+
+static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
+
+static clockid_t thread_cpu_clockid(Thread* thread) {
+ pthread_t tid = thread->osthread()->pthread_id();
+ clockid_t clockid;
+
+ // Get thread clockid
+ int rc = os::Linux::pthread_getcpuclockid(tid, &clockid);
+ assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code");
+ return clockid;
+}
+
+// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
+// are used by JVM M&M and JVMTI to get user+sys or user CPU time
+// of a thread.
+//
+// current_thread_cpu_time() and thread_cpu_time(Thread*) returns
+// the fast estimate available on the platform.
+
+jlong os::current_thread_cpu_time() {
+ if (os::Linux::supports_fast_thread_cpu_time()) {
+ return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
+ } else {
+ // return user + sys since the cost is the same
+ return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
+ }
+}
+
+jlong os::thread_cpu_time(Thread* thread) {
+ // consistent with what current_thread_cpu_time() returns
+ if (os::Linux::supports_fast_thread_cpu_time()) {
+ return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
+ } else {
+ return slow_thread_cpu_time(thread, true /* user + sys */);
+ }
+}
+
+jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
+ if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
+ return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
+ } else {
+ return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
+ }
+}
+
+jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
+ if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
+ return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
+ } else {
+ return slow_thread_cpu_time(thread, user_sys_cpu_time);
+ }
+}
+
+// -1 on error.
+static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
+ pid_t tid = thread->osthread()->thread_id();
+ char *s;
+ char stat[2048];
+ int statlen;
+ char proc_name[64];
+ int count;
+ long sys_time, user_time;
+ char cdummy;
+ int idummy;
+ long ldummy;
+ FILE *fp;
+
+ snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid);
+ fp = fopen(proc_name, "r");
+ if (fp == NULL) return -1;
+ statlen = fread(stat, 1, 2047, fp);
+ stat[statlen] = '\0';
+ fclose(fp);
+
+ // Skip pid and the command string. Note that we could be dealing with
+ // weird command names, e.g. user could decide to rename java launcher
+ // to "java 1.4.2 :)", then the stat file would look like
+ // 1234 (java 1.4.2 :)) R ... ...
+ // We don't really need to know the command string, just find the last
+ // occurrence of ")" and then start parsing from there. See bug 4726580.
+ s = strrchr(stat, ')');
+ if (s == NULL) return -1;
+
+ // Skip blank chars
+ do { s++; } while (s && isspace(*s));
+
+ count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
+ &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy,
+ &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
+ &user_time, &sys_time);
+ if (count != 13) return -1;
+ if (user_sys_cpu_time) {
+ return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
+ } else {
+ return (jlong)user_time * (1000000000 / clock_tics_per_sec);
+ }
+}
+
+void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
+ info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
+ info_ptr->may_skip_backward = false; // elapsed time not wall time
+ info_ptr->may_skip_forward = false; // elapsed time not wall time
+ info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
+}
+
+void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
+ info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
+ info_ptr->may_skip_backward = false; // elapsed time not wall time
+ info_ptr->may_skip_forward = false; // elapsed time not wall time
+ info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
+}
+
+bool os::is_thread_cpu_time_supported() {
+ return true;
+}
+
+// System loadavg support. Returns -1 if load average cannot be obtained.
+// Linux doesn't yet have a (official) notion of processor sets,
+// so just return the system wide load average.
+int os::loadavg(double loadavg[], int nelem) {
+ return ::getloadavg(loadavg, nelem);
+}
+
+void os::pause() {
+ char filename[MAX_PATH];
+ if (PauseAtStartupFile && PauseAtStartupFile[0]) {
+ jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
+ } else {
+ jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
+ }
+
+ int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+ if (fd != -1) {
+ struct stat buf;
+ ::close(fd);
+ while (::stat(filename, &buf) == 0) {
+ (void)::poll(NULL, 0, 100);
+ }
+ } else {
+ jio_fprintf(stderr,
+ "Could not open pause file '%s', continuing immediately.\n", filename);
+ }
+}
+
+extern char** environ;
+
+// Run the specified command in a separate process. Return its exit value,
+// or -1 on failure (e.g. can't fork a new process).
+// Unlike system(), this function can be called from signal handler. It
+// doesn't block SIGINT et al.
+int os::fork_and_exec(char* cmd) {
+ const char * argv[4] = {"sh", "-c", cmd, NULL};
+
+ pid_t pid = fork();
+
+ if (pid < 0) {
+ // fork failed
+ return -1;
+
+ } else if (pid == 0) {
+ // child process
+
+ execve("/bin/sh", (char* const*)argv, environ);
+
+ // execve failed
+ _exit(-1);
+
+ } else {
+ // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
+ // care about the actual exit code, for now.
+
+ int status;
+
+ // Wait for the child process to exit. This returns immediately if
+ // the child has already exited. */
+ while (waitpid(pid, &status, 0) < 0) {
+ switch (errno) {
+ case ECHILD: return 0;
+ case EINTR: break;
+ default: return -1;
+ }
+ }
+
+ if (WIFEXITED(status)) {
+ // The child exited normally; get its exit code.
+ return WEXITSTATUS(status);
+ } else if (WIFSIGNALED(status)) {
+ // The child exited because of a signal
+ // The best value to return is 0x80 + signal number,
+ // because that is what all Unix shells do, and because
+ // it allows callers to distinguish between process exit and
+ // process death by signal.
+ return 0x80 + WTERMSIG(status);
+ } else {
+ // Unknown exit code; pass it through
+ return status;
+ }
+ }
+}
+
+// is_headless_jre()
+//
+// Test for the existence of xawt/libmawt.so or libawt_xawt.so
+// in order to report if we are running in a headless jre
+//
+// Since JDK8 xawt/libmawt.so was moved into the same directory
+// as libawt.so, and renamed libawt_xawt.so
+//
+bool os::is_headless_jre() {
+ struct stat statbuf;
+ char buf[MAXPATHLEN];
+ char libmawtpath[MAXPATHLEN];
+ const char *xawtstr = "/xawt/libmawt.so";
+ const char *new_xawtstr = "/libawt_xawt.so";
+ char *p;
+
+ // Get path to libjvm.so
+ os::jvm_path(buf, sizeof(buf));
+
+ // Get rid of libjvm.so
+ p = strrchr(buf, '/');
+ if (p == NULL) {
+ return false;
+ } else {
+ *p = '\0';
+ }
+
+ // Get rid of client or server
+ p = strrchr(buf, '/');
+ if (p == NULL) {
+ return false;
+ } else {
+ *p = '\0';
+ }
+
+ // check xawt/libmawt.so
+ strcpy(libmawtpath, buf);
+ strcat(libmawtpath, xawtstr);
+ if (::stat(libmawtpath, &statbuf) == 0) return false;
+
+ // check libawt_xawt.so
+ strcpy(libmawtpath, buf);
+ strcat(libmawtpath, new_xawtstr);
+ if (::stat(libmawtpath, &statbuf) == 0) return false;
+
+ return true;
+}
+
+// Get the default path to the core file
+// Returns the length of the string
+int os::get_core_path(char* buffer, size_t bufferSize) {
+ /*
+ * Max length of /proc/sys/kernel/core_pattern is 128 characters.
+ * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
+ */
+ const int core_pattern_len = 129;
+ char core_pattern[core_pattern_len] = {0};
+
+ int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY);
+ if (core_pattern_file == -1) {
+ return -1;
+ }
+
+ ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len);
+ ::close(core_pattern_file);
+ if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') {
+ return -1;
+ }
+ if (core_pattern[ret-1] == '\n') {
+ core_pattern[ret-1] = '\0';
+ } else {
+ core_pattern[ret] = '\0';
+ }
+
+ char *pid_pos = strstr(core_pattern, "%p");
+ int written;
+
+ if (core_pattern[0] == '/') {
+ written = jio_snprintf(buffer, bufferSize, "%s", core_pattern);
+ } else {
+ char cwd[PATH_MAX];
+
+ const char* p = get_current_directory(cwd, PATH_MAX);
+ if (p == NULL) {
+ return -1;
+ }
+
+ if (core_pattern[0] == '|') {
+ written = jio_snprintf(buffer, bufferSize,
+ "\"%s\" (or dumping to %s/core.%d)",
+ &core_pattern[1], p, current_process_id());
+ } else {
+ written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern);
+ }
+ }
+
+ if (written < 0) {
+ return -1;
+ }
+
+ if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) {
+ int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY);
+
+ if (core_uses_pid_file != -1) {
+ char core_uses_pid = 0;
+ ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1);
+ ::close(core_uses_pid_file);
+
+ if (core_uses_pid == '1') {
+ jio_snprintf(buffer + written, bufferSize - written,
+ ".%d", current_process_id());
+ }
+ }
+ }
+
+ return strlen(buffer);
+}
+
+bool os::start_debugging(char *buf, int buflen) {
+ int len = (int)strlen(buf);
+ char *p = &buf[len];
+
+ jio_snprintf(p, buflen-len,
+ "\n\n"
+ "Do you want to debug the problem?\n\n"
+ "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n"
+ "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
+ "Otherwise, press RETURN to abort...",
+ os::current_process_id(), os::current_process_id(),
+ os::current_thread_id(), os::current_thread_id());
+
+ bool yes = os::message_box("Unexpected Error", buf);
+
+ if (yes) {
+ // yes, user asked VM to launch debugger
+ jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d",
+ os::current_process_id(), os::current_process_id());
+
+ os::fork_and_exec(buf);
+ yes = false;
+ }
+ return yes;
+}
+
+
+// Java/Compiler thread:
+//
+// Low memory addresses
+// P0 +------------------------+
+// | |\ Java thread created by VM does not have glibc
+// | glibc guard page | - guard page, attached Java thread usually has
+// | |/ 1 glibc guard page.
+// P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
+// | |\
+// | HotSpot Guard Pages | - red, yellow and reserved pages
+// | |/
+// +------------------------+ JavaThread::stack_reserved_zone_base()
+// | |\
+// | Normal Stack | -
+// | |/
+// P2 +------------------------+ Thread::stack_base()
+//
+// Non-Java thread:
+//
+// Low memory addresses
+// P0 +------------------------+
+// | |\
+// | glibc guard page | - usually 1 page
+// | |/
+// P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
+// | |\
+// | Normal Stack | -
+// | |/
+// P2 +------------------------+ Thread::stack_base()
+//
+// ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size
+// returned from pthread_attr_getstack().
+// ** Due to NPTL implementation error, linux takes the glibc guard page out
+// of the stack size given in pthread_attr. We work around this for
+// threads created by the VM. (We adapt bottom to be P1 and size accordingly.)
+//
+#ifndef ZERO
+static void current_stack_region(address * bottom, size_t * size) {
+ if (os::Linux::is_initial_thread()) {
+ // initial thread needs special handling because pthread_getattr_np()
+ // may return bogus value.
+ *bottom = os::Linux::initial_thread_stack_bottom();
+ *size = os::Linux::initial_thread_stack_size();
+ } else {
+ pthread_attr_t attr;
+
+ int rslt = pthread_getattr_np(pthread_self(), &attr);
+
+ // JVM needs to know exact stack location, abort if it fails
+ if (rslt != 0) {
+ if (rslt == ENOMEM) {
+ vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
+ } else {
+ fatal("pthread_getattr_np failed with error = %d", rslt);
+ }
+ }
+
+ if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
+ fatal("Cannot locate current stack attributes!");
+ }
+
+ // Work around NPTL stack guard error.
+ size_t guard_size = 0;
+ rslt = pthread_attr_getguardsize(&attr, &guard_size);
+ if (rslt != 0) {
+ fatal("pthread_attr_getguardsize failed with error = %d", rslt);
+ }
+ *bottom += guard_size;
+ *size -= guard_size;
+
+ pthread_attr_destroy(&attr);
+
+ }
+ assert(os::current_stack_pointer() >= *bottom &&
+ os::current_stack_pointer() < *bottom + *size, "just checking");
+}
+
+address os::current_stack_base() {
+ address bottom;
+ size_t size;
+ current_stack_region(&bottom, &size);
+ return (bottom + size);
+}
+
+size_t os::current_stack_size() {
+ // This stack size includes the usable stack and HotSpot guard pages
+ // (for the threads that have Hotspot guard pages).
+ address bottom;
+ size_t size;
+ current_stack_region(&bottom, &size);
+ return size;
+}
+#endif
+
+static inline struct timespec get_mtime(const char* filename) {
+ struct stat st;
+ int ret = os::stat(filename, &st);
+ assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
+ return st.st_mtim;
+}
+
+int os::compare_file_modified_times(const char* file1, const char* file2) {
+ struct timespec filetime1 = get_mtime(file1);
+ struct timespec filetime2 = get_mtime(file2);
+ int diff = filetime1.tv_sec - filetime2.tv_sec;
+ if (diff == 0) {
+ return filetime1.tv_nsec - filetime2.tv_nsec;
+ }
+ return diff;
+}
+
+/////////////// Unit tests ///////////////
+
+#ifndef PRODUCT
+
+#define test_log(...) \
+ do { \
+ if (VerboseInternalVMTests) { \
+ tty->print_cr(__VA_ARGS__); \
+ tty->flush(); \
+ } \
+ } while (false)
+
+class TestReserveMemorySpecial : AllStatic {
+ public:
+ static void small_page_write(void* addr, size_t size) {
+ size_t page_size = os::vm_page_size();
+
+ char* end = (char*)addr + size;
+ for (char* p = (char*)addr; p < end; p += page_size) {
+ *p = 1;
+ }
+ }
+
+ static void test_reserve_memory_special_huge_tlbfs_only(size_t size) {
+ if (!UseHugeTLBFS) {
+ return;
+ }
+
+ test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size);
+
+ char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false);
+
+ if (addr != NULL) {
+ small_page_write(addr, size);
+
+ os::Linux::release_memory_special_huge_tlbfs(addr, size);
+ }
+ }
+
+ static void test_reserve_memory_special_huge_tlbfs_only() {
+ if (!UseHugeTLBFS) {
+ return;
+ }
+
+ size_t lp = os::large_page_size();
+
+ for (size_t size = lp; size <= lp * 10; size += lp) {
+ test_reserve_memory_special_huge_tlbfs_only(size);
+ }
+ }
+
+ static void test_reserve_memory_special_huge_tlbfs_mixed() {
+ size_t lp = os::large_page_size();
+ size_t ag = os::vm_allocation_granularity();
+
+ // sizes to test
+ const size_t sizes[] = {
+ lp, lp + ag, lp + lp / 2, lp * 2,
+ lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2,
+ lp * 10, lp * 10 + lp / 2
+ };
+ const int num_sizes = sizeof(sizes) / sizeof(size_t);
+
+ // For each size/alignment combination, we test three scenarios:
+ // 1) with req_addr == NULL
+ // 2) with a non-null req_addr at which we expect to successfully allocate
+ // 3) with a non-null req_addr which contains a pre-existing mapping, at which we
+ // expect the allocation to either fail or to ignore req_addr
+
+ // Pre-allocate two areas; they shall be as large as the largest allocation
+ // and aligned to the largest alignment we will be testing.
+ const size_t mapping_size = sizes[num_sizes - 1] * 2;
+ char* const mapping1 = (char*) ::mmap(NULL, mapping_size,
+ PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
+ -1, 0);
+ assert(mapping1 != MAP_FAILED, "should work");
+
+ char* const mapping2 = (char*) ::mmap(NULL, mapping_size,
+ PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
+ -1, 0);
+ assert(mapping2 != MAP_FAILED, "should work");
+
+ // Unmap the first mapping, but leave the second mapping intact: the first
+ // mapping will serve as a value for a "good" req_addr (case 2). The second
+ // mapping, still intact, as "bad" req_addr (case 3).
+ ::munmap(mapping1, mapping_size);
+
+ // Case 1
+ test_log("%s, req_addr NULL:", __FUNCTION__);
+ test_log("size align result");
+
+ for (int i = 0; i < num_sizes; i++) {
+ const size_t size = sizes[i];
+ for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
+ char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false);
+ test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s",
+ size, alignment, p2i(p), (p != NULL ? "" : "(failed)"));
+ if (p != NULL) {
+ assert(is_aligned(p, alignment), "must be");
+ small_page_write(p, size);
+ os::Linux::release_memory_special_huge_tlbfs(p, size);
+ }
+ }
+ }
+
+ // Case 2
+ test_log("%s, req_addr non-NULL:", __FUNCTION__);
+ test_log("size align req_addr result");
+
+ for (int i = 0; i < num_sizes; i++) {
+ const size_t size = sizes[i];
+ for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
+ char* const req_addr = align_up(mapping1, alignment);
+ char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
+ test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
+ size, alignment, p2i(req_addr), p2i(p),
+ ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)")));
+ if (p != NULL) {
+ assert(p == req_addr, "must be");
+ small_page_write(p, size);
+ os::Linux::release_memory_special_huge_tlbfs(p, size);
+ }
+ }
+ }
+
+ // Case 3
+ test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__);
+ test_log("size align req_addr result");
+
+ for (int i = 0; i < num_sizes; i++) {
+ const size_t size = sizes[i];
+ for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
+ char* const req_addr = align_up(mapping2, alignment);
+ char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false);
+ test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s",
+ size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)")));
+ // as the area around req_addr contains already existing mappings, the API should always
+ // return NULL (as per contract, it cannot return another address)
+ assert(p == NULL, "must be");
+ }
+ }
+
+ ::munmap(mapping2, mapping_size);
+
+ }
+
+ static void test_reserve_memory_special_huge_tlbfs() {
+ if (!UseHugeTLBFS) {
+ return;
+ }
+
+ test_reserve_memory_special_huge_tlbfs_only();
+ test_reserve_memory_special_huge_tlbfs_mixed();
+ }
+
+ static void test_reserve_memory_special_shm(size_t size, size_t alignment) {
+ if (!UseSHM) {
+ return;
+ }
+
+ test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment);
+
+ char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false);
+
+ if (addr != NULL) {
+ assert(is_aligned(addr, alignment), "Check");
+ assert(is_aligned(addr, os::large_page_size()), "Check");
+
+ small_page_write(addr, size);
+
+ os::Linux::release_memory_special_shm(addr, size);
+ }
+ }
+
+ static void test_reserve_memory_special_shm() {
+ size_t lp = os::large_page_size();
+ size_t ag = os::vm_allocation_granularity();
+
+ for (size_t size = ag; size < lp * 3; size += ag) {
+ for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) {
+ test_reserve_memory_special_shm(size, alignment);
+ }
+ }
+ }
+
+ static void test() {
+ test_reserve_memory_special_huge_tlbfs();
+ test_reserve_memory_special_shm();
+ }
+};
+
+void TestReserveMemorySpecial_test() {
+ TestReserveMemorySpecial::test();
+}
+
+#endif