--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/os/posix/os_posix.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1977 @@
+/*
+ * 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.
+ *
+ */
+
+#include "utilities/globalDefinitions.hpp"
+#include "prims/jvm.h"
+#include "runtime/frame.inline.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/os.hpp"
+#include "utilities/align.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/vmError.hpp"
+
+#ifndef __APPLE__
+// POSIX unamed semaphores are not supported on OS X.
+#include "semaphore_posix.hpp"
+#endif
+
+#include <dlfcn.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <sys/resource.h>
+#include <sys/utsname.h>
+#include <time.h>
+#include <unistd.h>
+
+// Todo: provide a os::get_max_process_id() or similar. Number of processes
+// may have been configured, can be read more accurately from proc fs etc.
+#ifndef MAX_PID
+#define MAX_PID INT_MAX
+#endif
+#define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
+
+// Check core dump limit and report possible place where core can be found
+void os::check_dump_limit(char* buffer, size_t bufferSize) {
+ if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
+ jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
+ VMError::record_coredump_status(buffer, false);
+ return;
+ }
+
+ int n;
+ struct rlimit rlim;
+ bool success;
+
+ char core_path[PATH_MAX];
+ n = get_core_path(core_path, PATH_MAX);
+
+ if (n <= 0) {
+ jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
+ success = true;
+#ifdef LINUX
+ } else if (core_path[0] == '"') { // redirect to user process
+ jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
+ success = true;
+#endif
+ } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
+ jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
+ success = true;
+ } else {
+ switch(rlim.rlim_cur) {
+ case RLIM_INFINITY:
+ jio_snprintf(buffer, bufferSize, "%s", core_path);
+ success = true;
+ break;
+ case 0:
+ jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
+ success = false;
+ break;
+ default:
+ jio_snprintf(buffer, bufferSize, "%s (max size " UINT64_FORMAT " kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, uint64_t(rlim.rlim_cur) / 1024);
+ success = true;
+ break;
+ }
+ }
+
+ VMError::record_coredump_status(buffer, success);
+}
+
+int os::get_native_stack(address* stack, int frames, int toSkip) {
+ int frame_idx = 0;
+ int num_of_frames; // number of frames captured
+ frame fr = os::current_frame();
+ while (fr.pc() && frame_idx < frames) {
+ if (toSkip > 0) {
+ toSkip --;
+ } else {
+ stack[frame_idx ++] = fr.pc();
+ }
+ if (fr.fp() == NULL || fr.cb() != NULL ||
+ fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
+
+ if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
+ fr = os::get_sender_for_C_frame(&fr);
+ } else {
+ break;
+ }
+ }
+ num_of_frames = frame_idx;
+ for (; frame_idx < frames; frame_idx ++) {
+ stack[frame_idx] = NULL;
+ }
+
+ return num_of_frames;
+}
+
+
+bool os::unsetenv(const char* name) {
+ assert(name != NULL, "Null pointer");
+ return (::unsetenv(name) == 0);
+}
+
+int os::get_last_error() {
+ return errno;
+}
+
+bool os::is_debugger_attached() {
+ // not implemented
+ return false;
+}
+
+void os::wait_for_keypress_at_exit(void) {
+ // don't do anything on posix platforms
+ return;
+}
+
+// Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
+// so on posix, unmap the section at the start and at the end of the chunk that we mapped
+// rather than unmapping and remapping the whole chunk to get requested alignment.
+char* os::reserve_memory_aligned(size_t size, size_t alignment) {
+ assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
+ "Alignment must be a multiple of allocation granularity (page size)");
+ assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
+
+ size_t extra_size = size + alignment;
+ assert(extra_size >= size, "overflow, size is too large to allow alignment");
+
+ char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
+
+ if (extra_base == NULL) {
+ return NULL;
+ }
+
+ // Do manual alignment
+ char* aligned_base = align_up(extra_base, alignment);
+
+ // [ | | ]
+ // ^ extra_base
+ // ^ extra_base + begin_offset == aligned_base
+ // extra_base + begin_offset + size ^
+ // extra_base + extra_size ^
+ // |<>| == begin_offset
+ // end_offset == |<>|
+ size_t begin_offset = aligned_base - extra_base;
+ size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
+
+ if (begin_offset > 0) {
+ os::release_memory(extra_base, begin_offset);
+ }
+
+ if (end_offset > 0) {
+ os::release_memory(extra_base + begin_offset + size, end_offset);
+ }
+
+ return aligned_base;
+}
+
+int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
+ return vsnprintf(buf, len, fmt, args);
+}
+
+int os::get_fileno(FILE* fp) {
+ return NOT_AIX(::)fileno(fp);
+}
+
+struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
+ return gmtime_r(clock, res);
+}
+
+void os::Posix::print_load_average(outputStream* st) {
+ st->print("load average:");
+ double loadavg[3];
+ os::loadavg(loadavg, 3);
+ st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
+ st->cr();
+}
+
+void os::Posix::print_rlimit_info(outputStream* st) {
+ st->print("rlimit:");
+ struct rlimit rlim;
+
+ st->print(" STACK ");
+ getrlimit(RLIMIT_STACK, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
+
+ st->print(", CORE ");
+ getrlimit(RLIMIT_CORE, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
+
+ // Isn't there on solaris
+#if defined(AIX)
+ st->print(", NPROC ");
+ st->print("%d", sysconf(_SC_CHILD_MAX));
+#elif !defined(SOLARIS)
+ st->print(", NPROC ");
+ getrlimit(RLIMIT_NPROC, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
+#endif
+
+ st->print(", NOFILE ");
+ getrlimit(RLIMIT_NOFILE, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
+
+ st->print(", AS ");
+ getrlimit(RLIMIT_AS, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
+
+ st->print(", DATA ");
+ getrlimit(RLIMIT_DATA, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
+
+ st->print(", FSIZE ");
+ getrlimit(RLIMIT_FSIZE, &rlim);
+ if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
+ else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
+
+ st->cr();
+}
+
+void os::Posix::print_uname_info(outputStream* st) {
+ // kernel
+ st->print("uname:");
+ struct utsname name;
+ uname(&name);
+ st->print("%s ", name.sysname);
+#ifdef ASSERT
+ st->print("%s ", name.nodename);
+#endif
+ st->print("%s ", name.release);
+ st->print("%s ", name.version);
+ st->print("%s", name.machine);
+ st->cr();
+}
+
+bool os::get_host_name(char* buf, size_t buflen) {
+ struct utsname name;
+ uname(&name);
+ jio_snprintf(buf, buflen, "%s", name.nodename);
+ return true;
+}
+
+bool os::has_allocatable_memory_limit(julong* limit) {
+ struct rlimit rlim;
+ int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
+ // if there was an error when calling getrlimit, assume that there is no limitation
+ // on virtual memory.
+ bool result;
+ if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
+ result = false;
+ } else {
+ *limit = (julong)rlim.rlim_cur;
+ result = true;
+ }
+#ifdef _LP64
+ return result;
+#else
+ // arbitrary virtual space limit for 32 bit Unices found by testing. If
+ // getrlimit above returned a limit, bound it with this limit. Otherwise
+ // directly use it.
+ const julong max_virtual_limit = (julong)3800*M;
+ if (result) {
+ *limit = MIN2(*limit, max_virtual_limit);
+ } else {
+ *limit = max_virtual_limit;
+ }
+
+ // bound by actually allocatable memory. The algorithm uses two bounds, an
+ // upper and a lower limit. The upper limit is the current highest amount of
+ // memory that could not be allocated, the lower limit is the current highest
+ // amount of memory that could be allocated.
+ // The algorithm iteratively refines the result by halving the difference
+ // between these limits, updating either the upper limit (if that value could
+ // not be allocated) or the lower limit (if the that value could be allocated)
+ // until the difference between these limits is "small".
+
+ // the minimum amount of memory we care about allocating.
+ const julong min_allocation_size = M;
+
+ julong upper_limit = *limit;
+
+ // first check a few trivial cases
+ if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
+ *limit = upper_limit;
+ } else if (!is_allocatable(min_allocation_size)) {
+ // we found that not even min_allocation_size is allocatable. Return it
+ // anyway. There is no point to search for a better value any more.
+ *limit = min_allocation_size;
+ } else {
+ // perform the binary search.
+ julong lower_limit = min_allocation_size;
+ while ((upper_limit - lower_limit) > min_allocation_size) {
+ julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
+ temp_limit = align_down(temp_limit, min_allocation_size);
+ if (is_allocatable(temp_limit)) {
+ lower_limit = temp_limit;
+ } else {
+ upper_limit = temp_limit;
+ }
+ }
+ *limit = lower_limit;
+ }
+ return true;
+#endif
+}
+
+const char* os::get_current_directory(char *buf, size_t buflen) {
+ return getcwd(buf, buflen);
+}
+
+FILE* os::open(int fd, const char* mode) {
+ return ::fdopen(fd, mode);
+}
+
+void os::flockfile(FILE* fp) {
+ ::flockfile(fp);
+}
+
+void os::funlockfile(FILE* fp) {
+ ::funlockfile(fp);
+}
+
+// Builds a platform dependent Agent_OnLoad_<lib_name> function name
+// which is used to find statically linked in agents.
+// Parameters:
+// sym_name: Symbol in library we are looking for
+// lib_name: Name of library to look in, NULL for shared libs.
+// is_absolute_path == true if lib_name is absolute path to agent
+// such as "/a/b/libL.so"
+// == false if only the base name of the library is passed in
+// such as "L"
+char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
+ bool is_absolute_path) {
+ char *agent_entry_name;
+ size_t len;
+ size_t name_len;
+ size_t prefix_len = strlen(JNI_LIB_PREFIX);
+ size_t suffix_len = strlen(JNI_LIB_SUFFIX);
+ const char *start;
+
+ if (lib_name != NULL) {
+ name_len = strlen(lib_name);
+ if (is_absolute_path) {
+ // Need to strip path, prefix and suffix
+ if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
+ lib_name = ++start;
+ }
+ if (strlen(lib_name) <= (prefix_len + suffix_len)) {
+ return NULL;
+ }
+ lib_name += prefix_len;
+ name_len = strlen(lib_name) - suffix_len;
+ }
+ }
+ len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
+ agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
+ if (agent_entry_name == NULL) {
+ return NULL;
+ }
+ strcpy(agent_entry_name, sym_name);
+ if (lib_name != NULL) {
+ strcat(agent_entry_name, "_");
+ strncat(agent_entry_name, lib_name, name_len);
+ }
+ return agent_entry_name;
+}
+
+int os::sleep(Thread* thread, jlong millis, bool interruptible) {
+ assert(thread == Thread::current(), "thread consistency check");
+
+ ParkEvent * const slp = thread->_SleepEvent ;
+ slp->reset() ;
+ OrderAccess::fence() ;
+
+ if (interruptible) {
+ jlong prevtime = javaTimeNanos();
+
+ for (;;) {
+ if (os::is_interrupted(thread, true)) {
+ return OS_INTRPT;
+ }
+
+ jlong newtime = javaTimeNanos();
+
+ if (newtime - prevtime < 0) {
+ // time moving backwards, should only happen if no monotonic clock
+ // not a guarantee() because JVM should not abort on kernel/glibc bugs
+ assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
+ } else {
+ millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
+ }
+
+ if (millis <= 0) {
+ return OS_OK;
+ }
+
+ prevtime = newtime;
+
+ {
+ assert(thread->is_Java_thread(), "sanity check");
+ JavaThread *jt = (JavaThread *) thread;
+ ThreadBlockInVM tbivm(jt);
+ OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
+
+ jt->set_suspend_equivalent();
+ // cleared by handle_special_suspend_equivalent_condition() or
+ // java_suspend_self() via check_and_wait_while_suspended()
+
+ slp->park(millis);
+
+ // were we externally suspended while we were waiting?
+ jt->check_and_wait_while_suspended();
+ }
+ }
+ } else {
+ OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
+ jlong prevtime = javaTimeNanos();
+
+ for (;;) {
+ // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
+ // the 1st iteration ...
+ jlong newtime = javaTimeNanos();
+
+ if (newtime - prevtime < 0) {
+ // time moving backwards, should only happen if no monotonic clock
+ // not a guarantee() because JVM should not abort on kernel/glibc bugs
+ assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
+ } else {
+ millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
+ }
+
+ if (millis <= 0) break ;
+
+ prevtime = newtime;
+ slp->park(millis);
+ }
+ return OS_OK ;
+ }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// interrupt support
+
+void os::interrupt(Thread* thread) {
+ assert(Thread::current() == thread || Threads_lock->owned_by_self(),
+ "possibility of dangling Thread pointer");
+
+ OSThread* osthread = thread->osthread();
+
+ if (!osthread->interrupted()) {
+ osthread->set_interrupted(true);
+ // More than one thread can get here with the same value of osthread,
+ // resulting in multiple notifications. We do, however, want the store
+ // to interrupted() to be visible to other threads before we execute unpark().
+ OrderAccess::fence();
+ ParkEvent * const slp = thread->_SleepEvent ;
+ if (slp != NULL) slp->unpark() ;
+ }
+
+ // For JSR166. Unpark even if interrupt status already was set
+ if (thread->is_Java_thread())
+ ((JavaThread*)thread)->parker()->unpark();
+
+ ParkEvent * ev = thread->_ParkEvent ;
+ if (ev != NULL) ev->unpark() ;
+
+}
+
+bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
+ assert(Thread::current() == thread || Threads_lock->owned_by_self(),
+ "possibility of dangling Thread pointer");
+
+ OSThread* osthread = thread->osthread();
+
+ bool interrupted = osthread->interrupted();
+
+ // NOTE that since there is no "lock" around the interrupt and
+ // is_interrupted operations, there is the possibility that the
+ // interrupted flag (in osThread) will be "false" but that the
+ // low-level events will be in the signaled state. This is
+ // intentional. The effect of this is that Object.wait() and
+ // LockSupport.park() will appear to have a spurious wakeup, which
+ // is allowed and not harmful, and the possibility is so rare that
+ // it is not worth the added complexity to add yet another lock.
+ // For the sleep event an explicit reset is performed on entry
+ // to os::sleep, so there is no early return. It has also been
+ // recommended not to put the interrupted flag into the "event"
+ // structure because it hides the issue.
+ if (interrupted && clear_interrupted) {
+ osthread->set_interrupted(false);
+ // consider thread->_SleepEvent->reset() ... optional optimization
+ }
+
+ return interrupted;
+}
+
+
+
+static const struct {
+ int sig; const char* name;
+}
+ g_signal_info[] =
+ {
+ { SIGABRT, "SIGABRT" },
+#ifdef SIGAIO
+ { SIGAIO, "SIGAIO" },
+#endif
+ { SIGALRM, "SIGALRM" },
+#ifdef SIGALRM1
+ { SIGALRM1, "SIGALRM1" },
+#endif
+ { SIGBUS, "SIGBUS" },
+#ifdef SIGCANCEL
+ { SIGCANCEL, "SIGCANCEL" },
+#endif
+ { SIGCHLD, "SIGCHLD" },
+#ifdef SIGCLD
+ { SIGCLD, "SIGCLD" },
+#endif
+ { SIGCONT, "SIGCONT" },
+#ifdef SIGCPUFAIL
+ { SIGCPUFAIL, "SIGCPUFAIL" },
+#endif
+#ifdef SIGDANGER
+ { SIGDANGER, "SIGDANGER" },
+#endif
+#ifdef SIGDIL
+ { SIGDIL, "SIGDIL" },
+#endif
+#ifdef SIGEMT
+ { SIGEMT, "SIGEMT" },
+#endif
+ { SIGFPE, "SIGFPE" },
+#ifdef SIGFREEZE
+ { SIGFREEZE, "SIGFREEZE" },
+#endif
+#ifdef SIGGFAULT
+ { SIGGFAULT, "SIGGFAULT" },
+#endif
+#ifdef SIGGRANT
+ { SIGGRANT, "SIGGRANT" },
+#endif
+ { SIGHUP, "SIGHUP" },
+ { SIGILL, "SIGILL" },
+ { SIGINT, "SIGINT" },
+#ifdef SIGIO
+ { SIGIO, "SIGIO" },
+#endif
+#ifdef SIGIOINT
+ { SIGIOINT, "SIGIOINT" },
+#endif
+#ifdef SIGIOT
+// SIGIOT is there for BSD compatibility, but on most Unices just a
+// synonym for SIGABRT. The result should be "SIGABRT", not
+// "SIGIOT".
+#if (SIGIOT != SIGABRT )
+ { SIGIOT, "SIGIOT" },
+#endif
+#endif
+#ifdef SIGKAP
+ { SIGKAP, "SIGKAP" },
+#endif
+ { SIGKILL, "SIGKILL" },
+#ifdef SIGLOST
+ { SIGLOST, "SIGLOST" },
+#endif
+#ifdef SIGLWP
+ { SIGLWP, "SIGLWP" },
+#endif
+#ifdef SIGLWPTIMER
+ { SIGLWPTIMER, "SIGLWPTIMER" },
+#endif
+#ifdef SIGMIGRATE
+ { SIGMIGRATE, "SIGMIGRATE" },
+#endif
+#ifdef SIGMSG
+ { SIGMSG, "SIGMSG" },
+#endif
+ { SIGPIPE, "SIGPIPE" },
+#ifdef SIGPOLL
+ { SIGPOLL, "SIGPOLL" },
+#endif
+#ifdef SIGPRE
+ { SIGPRE, "SIGPRE" },
+#endif
+ { SIGPROF, "SIGPROF" },
+#ifdef SIGPTY
+ { SIGPTY, "SIGPTY" },
+#endif
+#ifdef SIGPWR
+ { SIGPWR, "SIGPWR" },
+#endif
+ { SIGQUIT, "SIGQUIT" },
+#ifdef SIGRECONFIG
+ { SIGRECONFIG, "SIGRECONFIG" },
+#endif
+#ifdef SIGRECOVERY
+ { SIGRECOVERY, "SIGRECOVERY" },
+#endif
+#ifdef SIGRESERVE
+ { SIGRESERVE, "SIGRESERVE" },
+#endif
+#ifdef SIGRETRACT
+ { SIGRETRACT, "SIGRETRACT" },
+#endif
+#ifdef SIGSAK
+ { SIGSAK, "SIGSAK" },
+#endif
+ { SIGSEGV, "SIGSEGV" },
+#ifdef SIGSOUND
+ { SIGSOUND, "SIGSOUND" },
+#endif
+#ifdef SIGSTKFLT
+ { SIGSTKFLT, "SIGSTKFLT" },
+#endif
+ { SIGSTOP, "SIGSTOP" },
+ { SIGSYS, "SIGSYS" },
+#ifdef SIGSYSERROR
+ { SIGSYSERROR, "SIGSYSERROR" },
+#endif
+#ifdef SIGTALRM
+ { SIGTALRM, "SIGTALRM" },
+#endif
+ { SIGTERM, "SIGTERM" },
+#ifdef SIGTHAW
+ { SIGTHAW, "SIGTHAW" },
+#endif
+ { SIGTRAP, "SIGTRAP" },
+#ifdef SIGTSTP
+ { SIGTSTP, "SIGTSTP" },
+#endif
+ { SIGTTIN, "SIGTTIN" },
+ { SIGTTOU, "SIGTTOU" },
+#ifdef SIGURG
+ { SIGURG, "SIGURG" },
+#endif
+ { SIGUSR1, "SIGUSR1" },
+ { SIGUSR2, "SIGUSR2" },
+#ifdef SIGVIRT
+ { SIGVIRT, "SIGVIRT" },
+#endif
+ { SIGVTALRM, "SIGVTALRM" },
+#ifdef SIGWAITING
+ { SIGWAITING, "SIGWAITING" },
+#endif
+#ifdef SIGWINCH
+ { SIGWINCH, "SIGWINCH" },
+#endif
+#ifdef SIGWINDOW
+ { SIGWINDOW, "SIGWINDOW" },
+#endif
+ { SIGXCPU, "SIGXCPU" },
+ { SIGXFSZ, "SIGXFSZ" },
+#ifdef SIGXRES
+ { SIGXRES, "SIGXRES" },
+#endif
+ { -1, NULL }
+};
+
+// Returned string is a constant. For unknown signals "UNKNOWN" is returned.
+const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
+
+ const char* ret = NULL;
+
+#ifdef SIGRTMIN
+ if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
+ if (sig == SIGRTMIN) {
+ ret = "SIGRTMIN";
+ } else if (sig == SIGRTMAX) {
+ ret = "SIGRTMAX";
+ } else {
+ jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
+ return out;
+ }
+ }
+#endif
+
+ if (sig > 0) {
+ for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
+ if (g_signal_info[idx].sig == sig) {
+ ret = g_signal_info[idx].name;
+ break;
+ }
+ }
+ }
+
+ if (!ret) {
+ if (!is_valid_signal(sig)) {
+ ret = "INVALID";
+ } else {
+ ret = "UNKNOWN";
+ }
+ }
+
+ if (out && outlen > 0) {
+ strncpy(out, ret, outlen);
+ out[outlen - 1] = '\0';
+ }
+ return out;
+}
+
+int os::Posix::get_signal_number(const char* signal_name) {
+ char tmp[30];
+ const char* s = signal_name;
+ if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
+ jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
+ s = tmp;
+ }
+ for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
+ if (strcmp(g_signal_info[idx].name, s) == 0) {
+ return g_signal_info[idx].sig;
+ }
+ }
+ return -1;
+}
+
+int os::get_signal_number(const char* signal_name) {
+ return os::Posix::get_signal_number(signal_name);
+}
+
+// Returns true if signal number is valid.
+bool os::Posix::is_valid_signal(int sig) {
+ // MacOS not really POSIX compliant: sigaddset does not return
+ // an error for invalid signal numbers. However, MacOS does not
+ // support real time signals and simply seems to have just 33
+ // signals with no holes in the signal range.
+#ifdef __APPLE__
+ return sig >= 1 && sig < NSIG;
+#else
+ // Use sigaddset to check for signal validity.
+ sigset_t set;
+ sigemptyset(&set);
+ if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
+ return false;
+ }
+ return true;
+#endif
+}
+
+// Returns:
+// NULL for an invalid signal number
+// "SIG<num>" for a valid but unknown signal number
+// signal name otherwise.
+const char* os::exception_name(int sig, char* buf, size_t size) {
+ if (!os::Posix::is_valid_signal(sig)) {
+ return NULL;
+ }
+ const char* const name = os::Posix::get_signal_name(sig, buf, size);
+ if (strcmp(name, "UNKNOWN") == 0) {
+ jio_snprintf(buf, size, "SIG%d", sig);
+ }
+ return buf;
+}
+
+#define NUM_IMPORTANT_SIGS 32
+// Returns one-line short description of a signal set in a user provided buffer.
+const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
+ assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
+ // Note: for shortness, just print out the first 32. That should
+ // cover most of the useful ones, apart from realtime signals.
+ for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
+ const int rc = sigismember(set, sig);
+ if (rc == -1 && errno == EINVAL) {
+ buffer[sig-1] = '?';
+ } else {
+ buffer[sig-1] = rc == 0 ? '0' : '1';
+ }
+ }
+ buffer[NUM_IMPORTANT_SIGS] = 0;
+ return buffer;
+}
+
+// Prints one-line description of a signal set.
+void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
+ char buf[NUM_IMPORTANT_SIGS + 1];
+ os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
+ st->print("%s", buf);
+}
+
+// Writes one-line description of a combination of sigaction.sa_flags into a user
+// provided buffer. Returns that buffer.
+const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
+ char* p = buffer;
+ size_t remaining = size;
+ bool first = true;
+ int idx = 0;
+
+ assert(buffer, "invalid argument");
+
+ if (size == 0) {
+ return buffer;
+ }
+
+ strncpy(buffer, "none", size);
+
+ const struct {
+ // NB: i is an unsigned int here because SA_RESETHAND is on some
+ // systems 0x80000000, which is implicitly unsigned. Assignining
+ // it to an int field would be an overflow in unsigned-to-signed
+ // conversion.
+ unsigned int i;
+ const char* s;
+ } flaginfo [] = {
+ { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
+ { SA_ONSTACK, "SA_ONSTACK" },
+ { SA_RESETHAND, "SA_RESETHAND" },
+ { SA_RESTART, "SA_RESTART" },
+ { SA_SIGINFO, "SA_SIGINFO" },
+ { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
+ { SA_NODEFER, "SA_NODEFER" },
+#ifdef AIX
+ { SA_ONSTACK, "SA_ONSTACK" },
+ { SA_OLDSTYLE, "SA_OLDSTYLE" },
+#endif
+ { 0, NULL }
+ };
+
+ for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
+ if (flags & flaginfo[idx].i) {
+ if (first) {
+ jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
+ first = false;
+ } else {
+ jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
+ }
+ const size_t len = strlen(p);
+ p += len;
+ remaining -= len;
+ }
+ }
+
+ buffer[size - 1] = '\0';
+
+ return buffer;
+}
+
+// Prints one-line description of a combination of sigaction.sa_flags.
+void os::Posix::print_sa_flags(outputStream* st, int flags) {
+ char buffer[0x100];
+ os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
+ st->print("%s", buffer);
+}
+
+// Helper function for os::Posix::print_siginfo_...():
+// return a textual description for signal code.
+struct enum_sigcode_desc_t {
+ const char* s_name;
+ const char* s_desc;
+};
+
+static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
+
+ const struct {
+ int sig; int code; const char* s_code; const char* s_desc;
+ } t1 [] = {
+ { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
+ { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
+ { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
+ { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
+ { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
+ { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
+ { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
+ { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
+#if defined(IA64) && defined(LINUX)
+ { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
+ { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
+#endif
+ { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
+ { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
+ { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
+ { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
+ { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
+ { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
+ { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
+ { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
+ { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
+ { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
+#ifdef AIX
+ // no explanation found what keyerr would be
+ { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
+#endif
+#if defined(IA64) && !defined(AIX)
+ { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
+#endif
+#if defined(__sparc) && defined(SOLARIS)
+// define Solaris Sparc M7 ADI SEGV signals
+#if !defined(SEGV_ACCADI)
+#define SEGV_ACCADI 3
+#endif
+ { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
+#if !defined(SEGV_ACCDERR)
+#define SEGV_ACCDERR 4
+#endif
+ { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
+#if !defined(SEGV_ACCPERR)
+#define SEGV_ACCPERR 5
+#endif
+ { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
+#endif // defined(__sparc) && defined(SOLARIS)
+ { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
+ { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
+ { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
+ { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
+ { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
+ { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
+ { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
+ { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
+ { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
+ { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
+ { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
+#ifdef SIGPOLL
+ { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
+ { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
+ { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
+ { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
+ { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
+#endif
+ { -1, -1, NULL, NULL }
+ };
+
+ // Codes valid in any signal context.
+ const struct {
+ int code; const char* s_code; const char* s_desc;
+ } t2 [] = {
+ { SI_USER, "SI_USER", "Signal sent by kill()." },
+ { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
+ { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
+ { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
+ { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
+ // Linux specific
+#ifdef SI_TKILL
+ { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
+#endif
+#ifdef SI_DETHREAD
+ { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
+#endif
+#ifdef SI_KERNEL
+ { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
+#endif
+#ifdef SI_SIGIO
+ { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
+#endif
+
+#ifdef AIX
+ { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
+ { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
+#endif
+
+#ifdef __sun
+ { SI_NOINFO, "SI_NOINFO", "No signal information" },
+ { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
+ { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
+#endif
+
+ { -1, NULL, NULL }
+ };
+
+ const char* s_code = NULL;
+ const char* s_desc = NULL;
+
+ for (int i = 0; t1[i].sig != -1; i ++) {
+ if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
+ s_code = t1[i].s_code;
+ s_desc = t1[i].s_desc;
+ break;
+ }
+ }
+
+ if (s_code == NULL) {
+ for (int i = 0; t2[i].s_code != NULL; i ++) {
+ if (t2[i].code == si->si_code) {
+ s_code = t2[i].s_code;
+ s_desc = t2[i].s_desc;
+ }
+ }
+ }
+
+ if (s_code == NULL) {
+ out->s_name = "unknown";
+ out->s_desc = "unknown";
+ return false;
+ }
+
+ out->s_name = s_code;
+ out->s_desc = s_desc;
+
+ return true;
+}
+
+void os::print_siginfo(outputStream* os, const void* si0) {
+
+ const siginfo_t* const si = (const siginfo_t*) si0;
+
+ char buf[20];
+ os->print("siginfo:");
+
+ if (!si) {
+ os->print(" <null>");
+ return;
+ }
+
+ const int sig = si->si_signo;
+
+ os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
+
+ enum_sigcode_desc_t ed;
+ get_signal_code_description(si, &ed);
+ os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
+
+ if (si->si_errno) {
+ os->print(", si_errno: %d", si->si_errno);
+ }
+
+ // Output additional information depending on the signal code.
+
+ // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
+ // so it depends on the context which member to use. For synchronous error signals,
+ // we print si_addr, unless the signal was sent by another process or thread, in
+ // which case we print out pid or tid of the sender.
+ if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
+ const pid_t pid = si->si_pid;
+ os->print(", si_pid: %ld", (long) pid);
+ if (IS_VALID_PID(pid)) {
+ const pid_t me = getpid();
+ if (me == pid) {
+ os->print(" (current process)");
+ }
+ } else {
+ os->print(" (invalid)");
+ }
+ os->print(", si_uid: %ld", (long) si->si_uid);
+ if (sig == SIGCHLD) {
+ os->print(", si_status: %d", si->si_status);
+ }
+ } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
+ sig == SIGTRAP || sig == SIGFPE) {
+ os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
+#ifdef SIGPOLL
+ } else if (sig == SIGPOLL) {
+ os->print(", si_band: %ld", si->si_band);
+#endif
+ }
+
+}
+
+int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
+ return pthread_sigmask(SIG_UNBLOCK, set, NULL);
+}
+
+address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
+#if defined(AIX)
+ return Aix::ucontext_get_pc(ctx);
+#elif defined(BSD)
+ return Bsd::ucontext_get_pc(ctx);
+#elif defined(LINUX)
+ return Linux::ucontext_get_pc(ctx);
+#elif defined(SOLARIS)
+ return Solaris::ucontext_get_pc(ctx);
+#else
+ VMError::report_and_die("unimplemented ucontext_get_pc");
+#endif
+}
+
+void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
+#if defined(AIX)
+ Aix::ucontext_set_pc(ctx, pc);
+#elif defined(BSD)
+ Bsd::ucontext_set_pc(ctx, pc);
+#elif defined(LINUX)
+ Linux::ucontext_set_pc(ctx, pc);
+#elif defined(SOLARIS)
+ Solaris::ucontext_set_pc(ctx, pc);
+#else
+ VMError::report_and_die("unimplemented ucontext_get_pc");
+#endif
+}
+
+char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
+ size_t stack_size = 0;
+ size_t guard_size = 0;
+ int detachstate = 0;
+ pthread_attr_getstacksize(attr, &stack_size);
+ pthread_attr_getguardsize(attr, &guard_size);
+ // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
+ LINUX_ONLY(stack_size -= guard_size);
+ pthread_attr_getdetachstate(attr, &detachstate);
+ jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
+ stack_size / 1024, guard_size / 1024,
+ (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
+ return buf;
+}
+
+char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
+
+ if (filename == NULL || outbuf == NULL || outbuflen < 1) {
+ assert(false, "os::Posix::realpath: invalid arguments.");
+ errno = EINVAL;
+ return NULL;
+ }
+
+ char* result = NULL;
+
+ // This assumes platform realpath() is implemented according to POSIX.1-2008.
+ // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
+ // output buffer is dynamically allocated and must be ::free()'d by the caller.
+ char* p = ::realpath(filename, NULL);
+ if (p != NULL) {
+ if (strlen(p) < outbuflen) {
+ strcpy(outbuf, p);
+ result = outbuf;
+ } else {
+ errno = ENAMETOOLONG;
+ }
+ ::free(p); // *not* os::free
+ } else {
+ // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
+ // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
+ // that it complains about the NULL we handed down as user buffer.
+ // In this case, use the user provided buffer but at least check whether realpath caused
+ // a memory overwrite.
+ if (errno == EINVAL) {
+ outbuf[outbuflen - 1] = '\0';
+ p = ::realpath(filename, outbuf);
+ if (p != NULL) {
+ guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
+ result = p;
+ }
+ }
+ }
+ return result;
+
+}
+
+
+// Check minimum allowable stack sizes for thread creation and to initialize
+// the java system classes, including StackOverflowError - depends on page
+// size.
+// The space needed for frames during startup is platform dependent. It
+// depends on word size, platform calling conventions, C frame layout and
+// interpreter/C1/C2 design decisions. Therefore this is given in a
+// platform (os/cpu) dependent constant.
+// To this, space for guard mechanisms is added, which depends on the
+// page size which again depends on the concrete system the VM is running
+// on. Space for libc guard pages is not included in this size.
+jint os::Posix::set_minimum_stack_sizes() {
+ size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
+
+ _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
+ JavaThread::stack_guard_zone_size() +
+ JavaThread::stack_shadow_zone_size();
+
+ _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
+ _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
+
+ size_t stack_size_in_bytes = ThreadStackSize * K;
+ if (stack_size_in_bytes != 0 &&
+ stack_size_in_bytes < _java_thread_min_stack_allowed) {
+ // The '-Xss' and '-XX:ThreadStackSize=N' options both set
+ // ThreadStackSize so we go with "Java thread stack size" instead
+ // of "ThreadStackSize" to be more friendly.
+ tty->print_cr("\nThe Java thread stack size specified is too small. "
+ "Specify at least " SIZE_FORMAT "k",
+ _java_thread_min_stack_allowed / K);
+ return JNI_ERR;
+ }
+
+ // Make the stack size a multiple of the page size so that
+ // the yellow/red zones can be guarded.
+ JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
+
+ // Reminder: a compiler thread is a Java thread.
+ _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
+ JavaThread::stack_guard_zone_size() +
+ JavaThread::stack_shadow_zone_size();
+
+ _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
+ _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
+
+ stack_size_in_bytes = CompilerThreadStackSize * K;
+ if (stack_size_in_bytes != 0 &&
+ stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
+ tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
+ "Specify at least " SIZE_FORMAT "k",
+ _compiler_thread_min_stack_allowed / K);
+ return JNI_ERR;
+ }
+
+ _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
+ _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
+
+ stack_size_in_bytes = VMThreadStackSize * K;
+ if (stack_size_in_bytes != 0 &&
+ stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
+ tty->print_cr("\nThe VMThreadStackSize specified is too small. "
+ "Specify at least " SIZE_FORMAT "k",
+ _vm_internal_thread_min_stack_allowed / K);
+ return JNI_ERR;
+ }
+ return JNI_OK;
+}
+
+// Called when creating the thread. The minimum stack sizes have already been calculated
+size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
+ size_t stack_size;
+ if (req_stack_size == 0) {
+ stack_size = default_stack_size(thr_type);
+ } else {
+ stack_size = req_stack_size;
+ }
+
+ switch (thr_type) {
+ case os::java_thread:
+ // Java threads use ThreadStackSize which default value can be
+ // changed with the flag -Xss
+ if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
+ // no requested size and we have a more specific default value
+ stack_size = JavaThread::stack_size_at_create();
+ }
+ stack_size = MAX2(stack_size,
+ _java_thread_min_stack_allowed);
+ break;
+ case os::compiler_thread:
+ if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
+ // no requested size and we have a more specific default value
+ stack_size = (size_t)(CompilerThreadStackSize * K);
+ }
+ stack_size = MAX2(stack_size,
+ _compiler_thread_min_stack_allowed);
+ break;
+ case os::vm_thread:
+ case os::pgc_thread:
+ case os::cgc_thread:
+ case os::watcher_thread:
+ default: // presume the unknown thr_type is a VM internal
+ if (req_stack_size == 0 && VMThreadStackSize > 0) {
+ // no requested size and we have a more specific default value
+ stack_size = (size_t)(VMThreadStackSize * K);
+ }
+
+ stack_size = MAX2(stack_size,
+ _vm_internal_thread_min_stack_allowed);
+ break;
+ }
+
+ // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
+ // Be careful not to round up to 0. Align down in that case.
+ if (stack_size <= SIZE_MAX - vm_page_size()) {
+ stack_size = align_up(stack_size, vm_page_size());
+ } else {
+ stack_size = align_down(stack_size, vm_page_size());
+ }
+
+ return stack_size;
+}
+
+Thread* os::ThreadCrashProtection::_protected_thread = NULL;
+os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
+volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
+
+os::ThreadCrashProtection::ThreadCrashProtection() {
+}
+
+/*
+ * See the caveats for this class in os_posix.hpp
+ * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
+ * method and returns false. If none of the signals are raised, returns true.
+ * The callback is supposed to provide the method that should be protected.
+ */
+bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
+ sigset_t saved_sig_mask;
+
+ Thread::muxAcquire(&_crash_mux, "CrashProtection");
+
+ _protected_thread = Thread::current_or_null();
+ assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
+
+ // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
+ // since on at least some systems (OS X) siglongjmp will restore the mask
+ // for the process, not the thread
+ pthread_sigmask(0, NULL, &saved_sig_mask);
+ if (sigsetjmp(_jmpbuf, 0) == 0) {
+ // make sure we can see in the signal handler that we have crash protection
+ // installed
+ _crash_protection = this;
+ cb.call();
+ // and clear the crash protection
+ _crash_protection = NULL;
+ _protected_thread = NULL;
+ Thread::muxRelease(&_crash_mux);
+ return true;
+ }
+ // this happens when we siglongjmp() back
+ pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
+ _crash_protection = NULL;
+ _protected_thread = NULL;
+ Thread::muxRelease(&_crash_mux);
+ return false;
+}
+
+void os::ThreadCrashProtection::restore() {
+ assert(_crash_protection != NULL, "must have crash protection");
+ siglongjmp(_jmpbuf, 1);
+}
+
+void os::ThreadCrashProtection::check_crash_protection(int sig,
+ Thread* thread) {
+
+ if (thread != NULL &&
+ thread == _protected_thread &&
+ _crash_protection != NULL) {
+
+ if (sig == SIGSEGV || sig == SIGBUS) {
+ _crash_protection->restore();
+ }
+ }
+}
+
+#define check_with_errno(check_type, cond, msg) \
+ do { \
+ int err = errno; \
+ check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
+ os::errno_name(err)); \
+} while (false)
+
+#define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
+#define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
+
+// POSIX unamed semaphores are not supported on OS X.
+#ifndef __APPLE__
+
+PosixSemaphore::PosixSemaphore(uint value) {
+ int ret = sem_init(&_semaphore, 0, value);
+
+ guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
+}
+
+PosixSemaphore::~PosixSemaphore() {
+ sem_destroy(&_semaphore);
+}
+
+void PosixSemaphore::signal(uint count) {
+ for (uint i = 0; i < count; i++) {
+ int ret = sem_post(&_semaphore);
+
+ assert_with_errno(ret == 0, "sem_post failed");
+ }
+}
+
+void PosixSemaphore::wait() {
+ int ret;
+
+ do {
+ ret = sem_wait(&_semaphore);
+ } while (ret != 0 && errno == EINTR);
+
+ assert_with_errno(ret == 0, "sem_wait failed");
+}
+
+bool PosixSemaphore::trywait() {
+ int ret;
+
+ do {
+ ret = sem_trywait(&_semaphore);
+ } while (ret != 0 && errno == EINTR);
+
+ assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
+
+ return ret == 0;
+}
+
+bool PosixSemaphore::timedwait(struct timespec ts) {
+ while (true) {
+ int result = sem_timedwait(&_semaphore, &ts);
+ if (result == 0) {
+ return true;
+ } else if (errno == EINTR) {
+ continue;
+ } else if (errno == ETIMEDOUT) {
+ return false;
+ } else {
+ assert_with_errno(false, "timedwait failed");
+ return false;
+ }
+ }
+}
+
+#endif // __APPLE__
+
+
+// Shared pthread_mutex/cond based PlatformEvent implementation.
+// Not currently usable by Solaris.
+
+#ifndef SOLARIS
+
+// Shared condattr object for use with relative timed-waits. Will be associated
+// with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
+// but otherwise whatever default is used by the platform - generally the
+// time-of-day clock.
+static pthread_condattr_t _condAttr[1];
+
+// Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
+// all systems (e.g. FreeBSD) map the default to "normal".
+static pthread_mutexattr_t _mutexAttr[1];
+
+// common basic initialization that is always supported
+static void pthread_init_common(void) {
+ int status;
+ if ((status = pthread_condattr_init(_condAttr)) != 0) {
+ fatal("pthread_condattr_init: %s", os::strerror(status));
+ }
+ if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
+ fatal("pthread_mutexattr_init: %s", os::strerror(status));
+ }
+ if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
+ fatal("pthread_mutexattr_settype: %s", os::strerror(status));
+ }
+}
+
+// Not all POSIX types and API's are available on all notionally "posix"
+// platforms. If we have build-time support then we will check for actual
+// runtime support via dlopen/dlsym lookup. This allows for running on an
+// older OS version compared to the build platform. But if there is no
+// build time support then there cannot be any runtime support as we do not
+// know what the runtime types would be (for example clockid_t might be an
+// int or int64_t).
+//
+#ifdef SUPPORTS_CLOCK_MONOTONIC
+
+// This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
+
+static int (*_clock_gettime)(clockid_t, struct timespec *);
+static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
+
+static bool _use_clock_monotonic_condattr;
+
+// Determine what POSIX API's are present and do appropriate
+// configuration.
+void os::Posix::init(void) {
+
+ // NOTE: no logging available when this is called. Put logging
+ // statements in init_2().
+
+ // Copied from os::Linux::clock_init(). The duplication is temporary.
+
+ // 1. Check for CLOCK_MONOTONIC support.
+
+ void* handle = NULL;
+
+ // For linux we need librt, for other OS we can find
+ // this function in regular libc.
+#ifdef NEEDS_LIBRT
+ // We do dlopen's in this particular order due to bug in linux
+ // dynamic loader (see 6348968) leading to crash on exit.
+ handle = dlopen("librt.so.1", RTLD_LAZY);
+ if (handle == NULL) {
+ handle = dlopen("librt.so", RTLD_LAZY);
+ }
+#endif
+
+ if (handle == NULL) {
+ handle = RTLD_DEFAULT;
+ }
+
+ _clock_gettime = NULL;
+
+ 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 != NULL && clock_gettime_func != NULL) {
+ // We assume that if both clock_gettime and clock_getres support
+ // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
+ 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;
+ } else {
+#ifdef NEEDS_LIBRT
+ // Close librt if there is no monotonic clock.
+ if (handle != RTLD_DEFAULT) {
+ dlclose(handle);
+ }
+#endif
+ }
+ }
+
+ // 2. Check for pthread_condattr_setclock support.
+
+ _pthread_condattr_setclock = NULL;
+
+ // libpthread is already loaded.
+ int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
+ (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
+ "pthread_condattr_setclock");
+ if (condattr_setclock_func != NULL) {
+ _pthread_condattr_setclock = condattr_setclock_func;
+ }
+
+ // Now do general initialization.
+
+ pthread_init_common();
+
+ int status;
+ if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
+ if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
+ if (status == EINVAL) {
+ _use_clock_monotonic_condattr = false;
+ warning("Unable to use monotonic clock with relative timed-waits" \
+ " - changes to the time-of-day clock may have adverse affects");
+ } else {
+ fatal("pthread_condattr_setclock: %s", os::strerror(status));
+ }
+ } else {
+ _use_clock_monotonic_condattr = true;
+ }
+ } else {
+ _use_clock_monotonic_condattr = false;
+ }
+}
+
+void os::Posix::init_2(void) {
+ log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
+ (_clock_gettime != NULL ? "" : " not"));
+ log_info(os)("Use of pthread_condattr_setclock is%s supported",
+ (_pthread_condattr_setclock != NULL ? "" : " not"));
+ log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
+ _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
+}
+
+#else // !SUPPORTS_CLOCK_MONOTONIC
+
+void os::Posix::init(void) {
+ pthread_init_common();
+}
+
+void os::Posix::init_2(void) {
+ log_info(os)("Use of CLOCK_MONOTONIC is not supported");
+ log_info(os)("Use of pthread_condattr_setclock is not supported");
+ log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
+}
+
+#endif // SUPPORTS_CLOCK_MONOTONIC
+
+os::PlatformEvent::PlatformEvent() {
+ int status = pthread_cond_init(_cond, _condAttr);
+ assert_status(status == 0, status, "cond_init");
+ status = pthread_mutex_init(_mutex, _mutexAttr);
+ assert_status(status == 0, status, "mutex_init");
+ _event = 0;
+ _nParked = 0;
+}
+
+// Utility to convert the given timeout to an absolute timespec
+// (based on the appropriate clock) to use with pthread_cond_timewait.
+// The clock queried here must be the clock used to manage the
+// timeout of the condition variable.
+//
+// The passed in timeout value is either a relative time in nanoseconds
+// or an absolute time in milliseconds. A relative timeout will be
+// associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
+// the default time-of-day clock will be used.
+
+// Given time is a 64-bit value and the time_t used in the timespec is
+// sometimes a signed-32-bit value we have to watch for overflow if times
+// way in the future are given. Further on Solaris versions
+// prior to 10 there is a restriction (see cond_timedwait) that the specified
+// number of seconds, in abstime, is less than current_time + 100000000.
+// As it will be over 20 years before "now + 100000000" will overflow we can
+// ignore overflow and just impose a hard-limit on seconds using the value
+// of "now + 100000000". This places a limit on the timeout of about 3.17
+// years from "now".
+//
+#define MAX_SECS 100000000
+
+// Calculate a new absolute time that is "timeout" nanoseconds from "now".
+// "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
+// on which clock is being used).
+static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
+ jlong now_part_sec, jlong unit) {
+ time_t max_secs = now_sec + MAX_SECS;
+
+ jlong seconds = timeout / NANOUNITS;
+ timeout %= NANOUNITS; // remaining nanos
+
+ if (seconds >= MAX_SECS) {
+ // More seconds than we can add, so pin to max_secs.
+ abstime->tv_sec = max_secs;
+ abstime->tv_nsec = 0;
+ } else {
+ abstime->tv_sec = now_sec + seconds;
+ long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
+ if (nanos >= NANOUNITS) { // overflow
+ abstime->tv_sec += 1;
+ nanos -= NANOUNITS;
+ }
+ abstime->tv_nsec = nanos;
+ }
+}
+
+// Unpack the given deadline in milliseconds since the epoch, into the given timespec.
+// The current time in seconds is also passed in to enforce an upper bound as discussed above.
+static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
+ time_t max_secs = now_sec + MAX_SECS;
+
+ jlong seconds = deadline / MILLIUNITS;
+ jlong millis = deadline % MILLIUNITS;
+
+ if (seconds >= max_secs) {
+ // Absolute seconds exceeds allowed max, so pin to max_secs.
+ abstime->tv_sec = max_secs;
+ abstime->tv_nsec = 0;
+ } else {
+ abstime->tv_sec = seconds;
+ abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
+ }
+}
+
+static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
+ DEBUG_ONLY(int max_secs = MAX_SECS;)
+
+ if (timeout < 0) {
+ timeout = 0;
+ }
+
+#ifdef SUPPORTS_CLOCK_MONOTONIC
+
+ if (_use_clock_monotonic_condattr && !isAbsolute) {
+ struct timespec now;
+ int status = _clock_gettime(CLOCK_MONOTONIC, &now);
+ assert_status(status == 0, status, "clock_gettime");
+ calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
+ DEBUG_ONLY(max_secs += now.tv_sec;)
+ } else {
+
+#else
+
+ { // Match the block scope.
+
+#endif // SUPPORTS_CLOCK_MONOTONIC
+
+ // Time-of-day clock is all we can reliably use.
+ struct timeval now;
+ int status = gettimeofday(&now, NULL);
+ assert_status(status == 0, errno, "gettimeofday");
+ if (isAbsolute) {
+ unpack_abs_time(abstime, timeout, now.tv_sec);
+ } else {
+ calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
+ }
+ DEBUG_ONLY(max_secs += now.tv_sec;)
+ }
+
+ assert(abstime->tv_sec >= 0, "tv_sec < 0");
+ assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
+ assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
+ assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
+}
+
+// PlatformEvent
+//
+// Assumption:
+// Only one parker can exist on an event, which is why we allocate
+// them per-thread. Multiple unparkers can coexist.
+//
+// _event serves as a restricted-range semaphore.
+// -1 : thread is blocked, i.e. there is a waiter
+// 0 : neutral: thread is running or ready,
+// could have been signaled after a wait started
+// 1 : signaled - thread is running or ready
+//
+// Having three states allows for some detection of bad usage - see
+// comments on unpark().
+
+void os::PlatformEvent::park() { // AKA "down()"
+ // Transitions for _event:
+ // -1 => -1 : illegal
+ // 1 => 0 : pass - return immediately
+ // 0 => -1 : block; then set _event to 0 before returning
+
+ // Invariant: Only the thread associated with the PlatformEvent
+ // may call park().
+ assert(_nParked == 0, "invariant");
+
+ int v;
+
+ // atomically decrement _event
+ for (;;) {
+ v = _event;
+ if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
+ }
+ guarantee(v >= 0, "invariant");
+
+ if (v == 0) { // Do this the hard way by blocking ...
+ int status = pthread_mutex_lock(_mutex);
+ assert_status(status == 0, status, "mutex_lock");
+ guarantee(_nParked == 0, "invariant");
+ ++_nParked;
+ while (_event < 0) {
+ // OS-level "spurious wakeups" are ignored
+ status = pthread_cond_wait(_cond, _mutex);
+ assert_status(status == 0, status, "cond_wait");
+ }
+ --_nParked;
+
+ _event = 0;
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "mutex_unlock");
+ // Paranoia to ensure our locked and lock-free paths interact
+ // correctly with each other.
+ OrderAccess::fence();
+ }
+ guarantee(_event >= 0, "invariant");
+}
+
+int os::PlatformEvent::park(jlong millis) {
+ // Transitions for _event:
+ // -1 => -1 : illegal
+ // 1 => 0 : pass - return immediately
+ // 0 => -1 : block; then set _event to 0 before returning
+
+ // Invariant: Only the thread associated with the Event/PlatformEvent
+ // may call park().
+ assert(_nParked == 0, "invariant");
+
+ int v;
+ // atomically decrement _event
+ for (;;) {
+ v = _event;
+ if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
+ }
+ guarantee(v >= 0, "invariant");
+
+ if (v == 0) { // Do this the hard way by blocking ...
+ struct timespec abst;
+ to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
+
+ int ret = OS_TIMEOUT;
+ int status = pthread_mutex_lock(_mutex);
+ assert_status(status == 0, status, "mutex_lock");
+ guarantee(_nParked == 0, "invariant");
+ ++_nParked;
+
+ while (_event < 0) {
+ status = pthread_cond_timedwait(_cond, _mutex, &abst);
+ assert_status(status == 0 || status == ETIMEDOUT,
+ status, "cond_timedwait");
+ // OS-level "spurious wakeups" are ignored unless the archaic
+ // FilterSpuriousWakeups is set false. That flag should be obsoleted.
+ if (!FilterSpuriousWakeups) break;
+ if (status == ETIMEDOUT) break;
+ }
+ --_nParked;
+
+ if (_event >= 0) {
+ ret = OS_OK;
+ }
+
+ _event = 0;
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "mutex_unlock");
+ // Paranoia to ensure our locked and lock-free paths interact
+ // correctly with each other.
+ OrderAccess::fence();
+ return ret;
+ }
+ return OS_OK;
+}
+
+void os::PlatformEvent::unpark() {
+ // Transitions for _event:
+ // 0 => 1 : just return
+ // 1 => 1 : just return
+ // -1 => either 0 or 1; must signal target thread
+ // That is, we can safely transition _event from -1 to either
+ // 0 or 1.
+ // See also: "Semaphores in Plan 9" by Mullender & Cox
+ //
+ // Note: Forcing a transition from "-1" to "1" on an unpark() means
+ // that it will take two back-to-back park() calls for the owning
+ // thread to block. This has the benefit of forcing a spurious return
+ // from the first park() call after an unpark() call which will help
+ // shake out uses of park() and unpark() without checking state conditions
+ // properly. This spurious return doesn't manifest itself in any user code
+ // but only in the correctly written condition checking loops of ObjectMonitor,
+ // Mutex/Monitor, Thread::muxAcquire and os::sleep
+
+ if (Atomic::xchg(1, &_event) >= 0) return;
+
+ int status = pthread_mutex_lock(_mutex);
+ assert_status(status == 0, status, "mutex_lock");
+ int anyWaiters = _nParked;
+ assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "mutex_unlock");
+
+ // Note that we signal() *after* dropping the lock for "immortal" Events.
+ // This is safe and avoids a common class of futile wakeups. In rare
+ // circumstances this can cause a thread to return prematurely from
+ // cond_{timed}wait() but the spurious wakeup is benign and the victim
+ // will simply re-test the condition and re-park itself.
+ // This provides particular benefit if the underlying platform does not
+ // provide wait morphing.
+
+ if (anyWaiters != 0) {
+ status = pthread_cond_signal(_cond);
+ assert_status(status == 0, status, "cond_signal");
+ }
+}
+
+// JSR166 support
+
+ os::PlatformParker::PlatformParker() {
+ int status;
+ status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
+ assert_status(status == 0, status, "cond_init rel");
+ status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
+ assert_status(status == 0, status, "cond_init abs");
+ status = pthread_mutex_init(_mutex, _mutexAttr);
+ assert_status(status == 0, status, "mutex_init");
+ _cur_index = -1; // mark as unused
+}
+
+// Parker::park decrements count if > 0, else does a condvar wait. Unpark
+// sets count to 1 and signals condvar. Only one thread ever waits
+// on the condvar. Contention seen when trying to park implies that someone
+// is unparking you, so don't wait. And spurious returns are fine, so there
+// is no need to track notifications.
+
+void Parker::park(bool isAbsolute, jlong time) {
+
+ // Optional fast-path check:
+ // Return immediately if a permit is available.
+ // We depend on Atomic::xchg() having full barrier semantics
+ // since we are doing a lock-free update to _counter.
+ if (Atomic::xchg(0, &_counter) > 0) return;
+
+ Thread* thread = Thread::current();
+ assert(thread->is_Java_thread(), "Must be JavaThread");
+ JavaThread *jt = (JavaThread *)thread;
+
+ // Optional optimization -- avoid state transitions if there's
+ // an interrupt pending.
+ if (Thread::is_interrupted(thread, false)) {
+ return;
+ }
+
+ // Next, demultiplex/decode time arguments
+ struct timespec absTime;
+ if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
+ return;
+ }
+ if (time > 0) {
+ to_abstime(&absTime, time, isAbsolute);
+ }
+
+ // Enter safepoint region
+ // Beware of deadlocks such as 6317397.
+ // The per-thread Parker:: mutex is a classic leaf-lock.
+ // In particular a thread must never block on the Threads_lock while
+ // holding the Parker:: mutex. If safepoints are pending both the
+ // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
+ ThreadBlockInVM tbivm(jt);
+
+ // Don't wait if cannot get lock since interference arises from
+ // unparking. Also re-check interrupt before trying wait.
+ if (Thread::is_interrupted(thread, false) ||
+ pthread_mutex_trylock(_mutex) != 0) {
+ return;
+ }
+
+ int status;
+ if (_counter > 0) { // no wait needed
+ _counter = 0;
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "invariant");
+ // Paranoia to ensure our locked and lock-free paths interact
+ // correctly with each other and Java-level accesses.
+ OrderAccess::fence();
+ return;
+ }
+
+ OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
+ jt->set_suspend_equivalent();
+ // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
+
+ assert(_cur_index == -1, "invariant");
+ if (time == 0) {
+ _cur_index = REL_INDEX; // arbitrary choice when not timed
+ status = pthread_cond_wait(&_cond[_cur_index], _mutex);
+ assert_status(status == 0, status, "cond_timedwait");
+ }
+ else {
+ _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
+ status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
+ assert_status(status == 0 || status == ETIMEDOUT,
+ status, "cond_timedwait");
+ }
+ _cur_index = -1;
+
+ _counter = 0;
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "invariant");
+ // Paranoia to ensure our locked and lock-free paths interact
+ // correctly with each other and Java-level accesses.
+ OrderAccess::fence();
+
+ // If externally suspended while waiting, re-suspend
+ if (jt->handle_special_suspend_equivalent_condition()) {
+ jt->java_suspend_self();
+ }
+}
+
+void Parker::unpark() {
+ int status = pthread_mutex_lock(_mutex);
+ assert_status(status == 0, status, "invariant");
+ const int s = _counter;
+ _counter = 1;
+ // must capture correct index before unlocking
+ int index = _cur_index;
+ status = pthread_mutex_unlock(_mutex);
+ assert_status(status == 0, status, "invariant");
+
+ // Note that we signal() *after* dropping the lock for "immortal" Events.
+ // This is safe and avoids a common class of futile wakeups. In rare
+ // circumstances this can cause a thread to return prematurely from
+ // cond_{timed}wait() but the spurious wakeup is benign and the victim
+ // will simply re-test the condition and re-park itself.
+ // This provides particular benefit if the underlying platform does not
+ // provide wait morphing.
+
+ if (s < 1 && index != -1) {
+ // thread is definitely parked
+ status = pthread_cond_signal(&_cond[index]);
+ assert_status(status == 0, status, "invariant");
+ }
+}
+
+
+#endif // !SOLARIS