src/hotspot/share/runtime/os.cpp
changeset 47216 71c04702a3d5
parent 47089 27050b653624
child 47765 b7c7428eaab9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/runtime/os.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1827 @@
+/*
+ * Copyright (c) 1997, 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 "precompiled.hpp"
+#include "classfile/classLoader.hpp"
+#include "classfile/javaClasses.hpp"
+#include "classfile/moduleEntry.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "code/codeCache.hpp"
+#include "code/icBuffer.hpp"
+#include "code/vtableStubs.hpp"
+#include "gc/shared/vmGCOperations.hpp"
+#include "interpreter/interpreter.hpp"
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/allocation.inline.hpp"
+#ifdef ASSERT
+#include "memory/guardedMemory.hpp"
+#endif
+#include "memory/resourceArea.hpp"
+#include "oops/oop.inline.hpp"
+#include "prims/jvm.h"
+#include "prims/jvm_misc.hpp"
+#include "prims/privilegedStack.hpp"
+#include "runtime/arguments.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/frame.inline.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/java.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/os.inline.hpp"
+#include "runtime/stubRoutines.hpp"
+#include "runtime/thread.inline.hpp"
+#include "runtime/vm_version.hpp"
+#include "services/attachListener.hpp"
+#include "services/mallocTracker.hpp"
+#include "services/memTracker.hpp"
+#include "services/nmtCommon.hpp"
+#include "services/threadService.hpp"
+#include "utilities/align.hpp"
+#include "utilities/defaultStream.hpp"
+#include "utilities/events.hpp"
+
+# include <signal.h>
+# include <errno.h>
+
+OSThread*         os::_starting_thread    = NULL;
+address           os::_polling_page       = NULL;
+volatile int32_t* os::_mem_serialize_page = NULL;
+uintptr_t         os::_serialize_page_mask = 0;
+volatile unsigned int os::_rand_seed      = 1;
+int               os::_processor_count    = 0;
+int               os::_initial_active_processor_count = 0;
+size_t            os::_page_sizes[os::page_sizes_max];
+
+#ifndef PRODUCT
+julong os::num_mallocs = 0;         // # of calls to malloc/realloc
+julong os::alloc_bytes = 0;         // # of bytes allocated
+julong os::num_frees = 0;           // # of calls to free
+julong os::free_bytes = 0;          // # of bytes freed
+#endif
+
+static juint cur_malloc_words = 0;  // current size for MallocMaxTestWords
+
+void os_init_globals() {
+  // Called from init_globals().
+  // See Threads::create_vm() in thread.cpp, and init.cpp.
+  os::init_globals();
+}
+
+// Fill in buffer with current local time as an ISO-8601 string.
+// E.g., yyyy-mm-ddThh:mm:ss-zzzz.
+// Returns buffer, or NULL if it failed.
+// This would mostly be a call to
+//     strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
+// except that on Windows the %z behaves badly, so we do it ourselves.
+// Also, people wanted milliseconds on there,
+// and strftime doesn't do milliseconds.
+char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
+  // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
+  //                                      1         2
+  //                             12345678901234567890123456789
+  // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
+  static const size_t needed_buffer = 29;
+
+  // Sanity check the arguments
+  if (buffer == NULL) {
+    assert(false, "NULL buffer");
+    return NULL;
+  }
+  if (buffer_length < needed_buffer) {
+    assert(false, "buffer_length too small");
+    return NULL;
+  }
+  // Get the current time
+  jlong milliseconds_since_19700101 = javaTimeMillis();
+  const int milliseconds_per_microsecond = 1000;
+  const time_t seconds_since_19700101 =
+    milliseconds_since_19700101 / milliseconds_per_microsecond;
+  const int milliseconds_after_second =
+    milliseconds_since_19700101 % milliseconds_per_microsecond;
+  // Convert the time value to a tm and timezone variable
+  struct tm time_struct;
+  if (utc) {
+    if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
+      assert(false, "Failed gmtime_pd");
+      return NULL;
+    }
+  } else {
+    if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
+      assert(false, "Failed localtime_pd");
+      return NULL;
+    }
+  }
+#if defined(_ALLBSD_SOURCE)
+  const time_t zone = (time_t) time_struct.tm_gmtoff;
+#else
+  const time_t zone = timezone;
+#endif
+
+  // If daylight savings time is in effect,
+  // we are 1 hour East of our time zone
+  const time_t seconds_per_minute = 60;
+  const time_t minutes_per_hour = 60;
+  const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
+  time_t UTC_to_local = zone;
+  if (time_struct.tm_isdst > 0) {
+    UTC_to_local = UTC_to_local - seconds_per_hour;
+  }
+
+  // No offset when dealing with UTC
+  if (utc) {
+    UTC_to_local = 0;
+  }
+
+  // Compute the time zone offset.
+  //    localtime_pd() sets timezone to the difference (in seconds)
+  //    between UTC and and local time.
+  //    ISO 8601 says we need the difference between local time and UTC,
+  //    we change the sign of the localtime_pd() result.
+  const time_t local_to_UTC = -(UTC_to_local);
+  // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
+  char sign_local_to_UTC = '+';
+  time_t abs_local_to_UTC = local_to_UTC;
+  if (local_to_UTC < 0) {
+    sign_local_to_UTC = '-';
+    abs_local_to_UTC = -(abs_local_to_UTC);
+  }
+  // Convert time zone offset seconds to hours and minutes.
+  const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
+  const time_t zone_min =
+    ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
+
+  // Print an ISO 8601 date and time stamp into the buffer
+  const int year = 1900 + time_struct.tm_year;
+  const int month = 1 + time_struct.tm_mon;
+  const int printed = jio_snprintf(buffer, buffer_length,
+                                   "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
+                                   year,
+                                   month,
+                                   time_struct.tm_mday,
+                                   time_struct.tm_hour,
+                                   time_struct.tm_min,
+                                   time_struct.tm_sec,
+                                   milliseconds_after_second,
+                                   sign_local_to_UTC,
+                                   zone_hours,
+                                   zone_min);
+  if (printed == 0) {
+    assert(false, "Failed jio_printf");
+    return NULL;
+  }
+  return buffer;
+}
+
+OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
+#ifdef ASSERT
+  if (!(!thread->is_Java_thread() ||
+         Thread::current() == thread  ||
+         Threads_lock->owned_by_self()
+         || thread->is_Compiler_thread()
+        )) {
+    assert(false, "possibility of dangling Thread pointer");
+  }
+#endif
+
+  if (p >= MinPriority && p <= MaxPriority) {
+    int priority = java_to_os_priority[p];
+    return set_native_priority(thread, priority);
+  } else {
+    assert(false, "Should not happen");
+    return OS_ERR;
+  }
+}
+
+// The mapping from OS priority back to Java priority may be inexact because
+// Java priorities can map M:1 with native priorities. If you want the definite
+// Java priority then use JavaThread::java_priority()
+OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
+  int p;
+  int os_prio;
+  OSReturn ret = get_native_priority(thread, &os_prio);
+  if (ret != OS_OK) return ret;
+
+  if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
+    for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
+  } else {
+    // niceness values are in reverse order
+    for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
+  }
+  priority = (ThreadPriority)p;
+  return OS_OK;
+}
+
+bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
+  int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
+  return (n != -1);
+}
+
+// Helper for dll_locate_lib.
+// Pass buffer and printbuffer as we already printed the path to buffer
+// when we called get_current_directory. This way we avoid another buffer
+// of size MAX_PATH.
+static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
+                                     const char* pname, char lastchar, const char* fname) {
+
+  // Concatenate path and file name, but don't print double path separators.
+  const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
+                        "" : os::file_separator();
+  int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
+  // Check whether file exists.
+  if (ret != -1) {
+    struct stat statbuf;
+    return os::stat(buffer, &statbuf) == 0;
+  }
+  return false;
+}
+
+bool os::dll_locate_lib(char *buffer, size_t buflen,
+                        const char* pname, const char* fname) {
+  bool retval = false;
+
+  size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
+  char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
+  if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
+    const size_t pnamelen = pname ? strlen(pname) : 0;
+
+    if (pnamelen == 0) {
+      // If no path given, use current working directory.
+      const char* p = get_current_directory(buffer, buflen);
+      if (p != NULL) {
+        const size_t plen = strlen(buffer);
+        const char lastchar = buffer[plen - 1];
+        retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
+                                          "", lastchar, fullfname);
+      }
+    } else if (strchr(pname, *os::path_separator()) != NULL) {
+      // A list of paths. Search for the path that contains the library.
+      int n;
+      char** pelements = split_path(pname, &n);
+      if (pelements != NULL) {
+        for (int i = 0; i < n; i++) {
+          char* path = pelements[i];
+          // Really shouldn't be NULL, but check can't hurt.
+          size_t plen = (path == NULL) ? 0 : strlen(path);
+          if (plen == 0) {
+            continue; // Skip the empty path values.
+          }
+          const char lastchar = path[plen - 1];
+          retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
+          if (retval) break;
+        }
+        // Release the storage allocated by split_path.
+        for (int i = 0; i < n; i++) {
+          if (pelements[i] != NULL) {
+            FREE_C_HEAP_ARRAY(char, pelements[i]);
+          }
+        }
+        FREE_C_HEAP_ARRAY(char*, pelements);
+      }
+    } else {
+      // A definite path.
+      const char lastchar = pname[pnamelen-1];
+      retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
+    }
+  }
+
+  FREE_C_HEAP_ARRAY(char*, fullfname);
+  return retval;
+}
+
+// --------------------- sun.misc.Signal (optional) ---------------------
+
+
+// SIGBREAK is sent by the keyboard to query the VM state
+#ifndef SIGBREAK
+#define SIGBREAK SIGQUIT
+#endif
+
+// sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
+
+
+static void signal_thread_entry(JavaThread* thread, TRAPS) {
+  os::set_priority(thread, NearMaxPriority);
+  while (true) {
+    int sig;
+    {
+      // FIXME : Currently we have not decided what should be the status
+      //         for this java thread blocked here. Once we decide about
+      //         that we should fix this.
+      sig = os::signal_wait();
+    }
+    if (sig == os::sigexitnum_pd()) {
+       // Terminate the signal thread
+       return;
+    }
+
+    switch (sig) {
+      case SIGBREAK: {
+        // Check if the signal is a trigger to start the Attach Listener - in that
+        // case don't print stack traces.
+        if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
+          continue;
+        }
+        // Print stack traces
+        // Any SIGBREAK operations added here should make sure to flush
+        // the output stream (e.g. tty->flush()) after output.  See 4803766.
+        // Each module also prints an extra carriage return after its output.
+        VM_PrintThreads op;
+        VMThread::execute(&op);
+        VM_PrintJNI jni_op;
+        VMThread::execute(&jni_op);
+        VM_FindDeadlocks op1(tty);
+        VMThread::execute(&op1);
+        Universe::print_heap_at_SIGBREAK();
+        if (PrintClassHistogram) {
+          VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
+          VMThread::execute(&op1);
+        }
+        if (JvmtiExport::should_post_data_dump()) {
+          JvmtiExport::post_data_dump();
+        }
+        break;
+      }
+      default: {
+        // Dispatch the signal to java
+        HandleMark hm(THREAD);
+        Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
+        if (klass != NULL) {
+          JavaValue result(T_VOID);
+          JavaCallArguments args;
+          args.push_int(sig);
+          JavaCalls::call_static(
+            &result,
+            klass,
+            vmSymbols::dispatch_name(),
+            vmSymbols::int_void_signature(),
+            &args,
+            THREAD
+          );
+        }
+        if (HAS_PENDING_EXCEPTION) {
+          // tty is initialized early so we don't expect it to be null, but
+          // if it is we can't risk doing an initialization that might
+          // trigger additional out-of-memory conditions
+          if (tty != NULL) {
+            char klass_name[256];
+            char tmp_sig_name[16];
+            const char* sig_name = "UNKNOWN";
+            InstanceKlass::cast(PENDING_EXCEPTION->klass())->
+              name()->as_klass_external_name(klass_name, 256);
+            if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
+              sig_name = tmp_sig_name;
+            warning("Exception %s occurred dispatching signal %s to handler"
+                    "- the VM may need to be forcibly terminated",
+                    klass_name, sig_name );
+          }
+          CLEAR_PENDING_EXCEPTION;
+        }
+      }
+    }
+  }
+}
+
+void os::init_before_ergo() {
+  initialize_initial_active_processor_count();
+  // We need to initialize large page support here because ergonomics takes some
+  // decisions depending on large page support and the calculated large page size.
+  large_page_init();
+
+  // We need to adapt the configured number of stack protection pages given
+  // in 4K pages to the actual os page size. We must do this before setting
+  // up minimal stack sizes etc. in os::init_2().
+  JavaThread::set_stack_red_zone_size     (align_up(StackRedPages      * 4 * K, vm_page_size()));
+  JavaThread::set_stack_yellow_zone_size  (align_up(StackYellowPages   * 4 * K, vm_page_size()));
+  JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
+  JavaThread::set_stack_shadow_zone_size  (align_up(StackShadowPages   * 4 * K, vm_page_size()));
+
+  // VM version initialization identifies some characteristics of the
+  // platform that are used during ergonomic decisions.
+  VM_Version::init_before_ergo();
+}
+
+void os::signal_init(TRAPS) {
+  if (!ReduceSignalUsage) {
+    // Setup JavaThread for processing signals
+    Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
+    InstanceKlass* ik = InstanceKlass::cast(k);
+    instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
+
+    const char thread_name[] = "Signal Dispatcher";
+    Handle string = java_lang_String::create_from_str(thread_name, CHECK);
+
+    // Initialize thread_oop to put it into the system threadGroup
+    Handle thread_group (THREAD, Universe::system_thread_group());
+    JavaValue result(T_VOID);
+    JavaCalls::call_special(&result, thread_oop,
+                           ik,
+                           vmSymbols::object_initializer_name(),
+                           vmSymbols::threadgroup_string_void_signature(),
+                           thread_group,
+                           string,
+                           CHECK);
+
+    Klass* group = SystemDictionary::ThreadGroup_klass();
+    JavaCalls::call_special(&result,
+                            thread_group,
+                            group,
+                            vmSymbols::add_method_name(),
+                            vmSymbols::thread_void_signature(),
+                            thread_oop,         // ARG 1
+                            CHECK);
+
+    os::signal_init_pd();
+
+    { MutexLocker mu(Threads_lock);
+      JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
+
+      // At this point it may be possible that no osthread was created for the
+      // JavaThread due to lack of memory. We would have to throw an exception
+      // in that case. However, since this must work and we do not allow
+      // exceptions anyway, check and abort if this fails.
+      if (signal_thread == NULL || signal_thread->osthread() == NULL) {
+        vm_exit_during_initialization("java.lang.OutOfMemoryError",
+                                      os::native_thread_creation_failed_msg());
+      }
+
+      java_lang_Thread::set_thread(thread_oop(), signal_thread);
+      java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
+      java_lang_Thread::set_daemon(thread_oop());
+
+      signal_thread->set_threadObj(thread_oop());
+      Threads::add(signal_thread);
+      Thread::start(signal_thread);
+    }
+    // Handle ^BREAK
+    os::signal(SIGBREAK, os::user_handler());
+  }
+}
+
+
+void os::terminate_signal_thread() {
+  if (!ReduceSignalUsage)
+    signal_notify(sigexitnum_pd());
+}
+
+
+// --------------------- loading libraries ---------------------
+
+typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
+extern struct JavaVM_ main_vm;
+
+static void* _native_java_library = NULL;
+
+void* os::native_java_library() {
+  if (_native_java_library == NULL) {
+    char buffer[JVM_MAXPATHLEN];
+    char ebuf[1024];
+
+    // Try to load verify dll first. In 1.3 java dll depends on it and is not
+    // always able to find it when the loading executable is outside the JDK.
+    // In order to keep working with 1.2 we ignore any loading errors.
+    if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
+                       "verify")) {
+      dll_load(buffer, ebuf, sizeof(ebuf));
+    }
+
+    // Load java dll
+    if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
+                       "java")) {
+      _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
+    }
+    if (_native_java_library == NULL) {
+      vm_exit_during_initialization("Unable to load native library", ebuf);
+    }
+
+#if defined(__OpenBSD__)
+    // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
+    // ignore errors
+    if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
+                       "net")) {
+      dll_load(buffer, ebuf, sizeof(ebuf));
+    }
+#endif
+  }
+  return _native_java_library;
+}
+
+/*
+ * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
+ * If check_lib == true then we are looking for an
+ * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
+ * this library is statically linked into the image.
+ * If check_lib == false then we will look for the appropriate symbol in the
+ * executable if agent_lib->is_static_lib() == true or in the shared library
+ * referenced by 'handle'.
+ */
+void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
+                              const char *syms[], size_t syms_len) {
+  assert(agent_lib != NULL, "sanity check");
+  const char *lib_name;
+  void *handle = agent_lib->os_lib();
+  void *entryName = NULL;
+  char *agent_function_name;
+  size_t i;
+
+  // If checking then use the agent name otherwise test is_static_lib() to
+  // see how to process this lookup
+  lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
+  for (i = 0; i < syms_len; i++) {
+    agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
+    if (agent_function_name == NULL) {
+      break;
+    }
+    entryName = dll_lookup(handle, agent_function_name);
+    FREE_C_HEAP_ARRAY(char, agent_function_name);
+    if (entryName != NULL) {
+      break;
+    }
+  }
+  return entryName;
+}
+
+// See if the passed in agent is statically linked into the VM image.
+bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
+                            size_t syms_len) {
+  void *ret;
+  void *proc_handle;
+  void *save_handle;
+
+  assert(agent_lib != NULL, "sanity check");
+  if (agent_lib->name() == NULL) {
+    return false;
+  }
+  proc_handle = get_default_process_handle();
+  // Check for Agent_OnLoad/Attach_lib_name function
+  save_handle = agent_lib->os_lib();
+  // We want to look in this process' symbol table.
+  agent_lib->set_os_lib(proc_handle);
+  ret = find_agent_function(agent_lib, true, syms, syms_len);
+  if (ret != NULL) {
+    // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
+    agent_lib->set_valid();
+    agent_lib->set_static_lib(true);
+    return true;
+  }
+  agent_lib->set_os_lib(save_handle);
+  return false;
+}
+
+// --------------------- heap allocation utilities ---------------------
+
+char *os::strdup(const char *str, MEMFLAGS flags) {
+  size_t size = strlen(str);
+  char *dup_str = (char *)malloc(size + 1, flags);
+  if (dup_str == NULL) return NULL;
+  strcpy(dup_str, str);
+  return dup_str;
+}
+
+char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
+  char* p = os::strdup(str, flags);
+  if (p == NULL) {
+    vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
+  }
+  return p;
+}
+
+
+#define paranoid                 0  /* only set to 1 if you suspect checking code has bug */
+
+#ifdef ASSERT
+
+static void verify_memory(void* ptr) {
+  GuardedMemory guarded(ptr);
+  if (!guarded.verify_guards()) {
+    tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
+    tty->print_cr("## memory stomp:");
+    guarded.print_on(tty);
+    fatal("memory stomping error");
+  }
+}
+
+#endif
+
+//
+// This function supports testing of the malloc out of memory
+// condition without really running the system out of memory.
+//
+static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
+  if (MallocMaxTestWords > 0) {
+    jint words = (jint)(alloc_size / BytesPerWord);
+
+    if ((cur_malloc_words + words) > MallocMaxTestWords) {
+      return true;
+    }
+    Atomic::add(words, (volatile jint *)&cur_malloc_words);
+  }
+  return false;
+}
+
+void* os::malloc(size_t size, MEMFLAGS flags) {
+  return os::malloc(size, flags, CALLER_PC);
+}
+
+void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
+  NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
+  NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
+
+  // Since os::malloc can be called when the libjvm.{dll,so} is
+  // first loaded and we don't have a thread yet we must accept NULL also here.
+  assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
+         "malloc() not allowed when crash protection is set");
+
+  if (size == 0) {
+    // return a valid pointer if size is zero
+    // if NULL is returned the calling functions assume out of memory.
+    size = 1;
+  }
+
+  // NMT support
+  NMT_TrackingLevel level = MemTracker::tracking_level();
+  size_t            nmt_header_size = MemTracker::malloc_header_size(level);
+
+#ifndef ASSERT
+  const size_t alloc_size = size + nmt_header_size;
+#else
+  const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
+  if (size + nmt_header_size > alloc_size) { // Check for rollover.
+    return NULL;
+  }
+#endif
+
+  // For the test flag -XX:MallocMaxTestWords
+  if (has_reached_max_malloc_test_peak(size)) {
+    return NULL;
+  }
+
+  u_char* ptr;
+  ptr = (u_char*)::malloc(alloc_size);
+
+#ifdef ASSERT
+  if (ptr == NULL) {
+    return NULL;
+  }
+  // Wrap memory with guard
+  GuardedMemory guarded(ptr, size + nmt_header_size);
+  ptr = guarded.get_user_ptr();
+#endif
+  if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
+    tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
+    breakpoint();
+  }
+  debug_only(if (paranoid) verify_memory(ptr));
+  if (PrintMalloc && tty != NULL) {
+    tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
+  }
+
+  // we do not track guard memory
+  return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
+}
+
+void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
+  return os::realloc(memblock, size, flags, CALLER_PC);
+}
+
+void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
+
+  // For the test flag -XX:MallocMaxTestWords
+  if (has_reached_max_malloc_test_peak(size)) {
+    return NULL;
+  }
+
+  if (size == 0) {
+    // return a valid pointer if size is zero
+    // if NULL is returned the calling functions assume out of memory.
+    size = 1;
+  }
+
+#ifndef ASSERT
+  NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
+  NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
+   // NMT support
+  void* membase = MemTracker::record_free(memblock);
+  NMT_TrackingLevel level = MemTracker::tracking_level();
+  size_t  nmt_header_size = MemTracker::malloc_header_size(level);
+  void* ptr = ::realloc(membase, size + nmt_header_size);
+  return MemTracker::record_malloc(ptr, size, memflags, stack, level);
+#else
+  if (memblock == NULL) {
+    return os::malloc(size, memflags, stack);
+  }
+  if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
+    tty->print_cr("os::realloc caught " PTR_FORMAT, p2i(memblock));
+    breakpoint();
+  }
+  // NMT support
+  void* membase = MemTracker::malloc_base(memblock);
+  verify_memory(membase);
+  // always move the block
+  void* ptr = os::malloc(size, memflags, stack);
+  if (PrintMalloc && tty != NULL) {
+    tty->print_cr("os::realloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, p2i(memblock), p2i(ptr));
+  }
+  // Copy to new memory if malloc didn't fail
+  if ( ptr != NULL ) {
+    GuardedMemory guarded(MemTracker::malloc_base(memblock));
+    // Guard's user data contains NMT header
+    size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
+    memcpy(ptr, memblock, MIN2(size, memblock_size));
+    if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
+    if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
+      tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
+      breakpoint();
+    }
+    os::free(memblock);
+  }
+  return ptr;
+#endif
+}
+
+
+void  os::free(void *memblock) {
+  NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
+#ifdef ASSERT
+  if (memblock == NULL) return;
+  if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
+    if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, p2i(memblock));
+    breakpoint();
+  }
+  void* membase = MemTracker::record_free(memblock);
+  verify_memory(membase);
+
+  GuardedMemory guarded(membase);
+  size_t size = guarded.get_user_size();
+  inc_stat_counter(&free_bytes, size);
+  membase = guarded.release_for_freeing();
+  if (PrintMalloc && tty != NULL) {
+      fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
+  }
+  ::free(membase);
+#else
+  void* membase = MemTracker::record_free(memblock);
+  ::free(membase);
+#endif
+}
+
+void os::init_random(unsigned int initval) {
+  _rand_seed = initval;
+}
+
+
+static int random_helper(unsigned int rand_seed) {
+  /* standard, well-known linear congruential random generator with
+   * next_rand = (16807*seed) mod (2**31-1)
+   * see
+   * (1) "Random Number Generators: Good Ones Are Hard to Find",
+   *      S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
+   * (2) "Two Fast Implementations of the 'Minimal Standard' Random
+   *     Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
+  */
+  const unsigned int a = 16807;
+  const unsigned int m = 2147483647;
+  const int q = m / a;        assert(q == 127773, "weird math");
+  const int r = m % a;        assert(r == 2836, "weird math");
+
+  // compute az=2^31p+q
+  unsigned int lo = a * (rand_seed & 0xFFFF);
+  unsigned int hi = a * (rand_seed >> 16);
+  lo += (hi & 0x7FFF) << 16;
+
+  // if q overflowed, ignore the overflow and increment q
+  if (lo > m) {
+    lo &= m;
+    ++lo;
+  }
+  lo += hi >> 15;
+
+  // if (p+q) overflowed, ignore the overflow and increment (p+q)
+  if (lo > m) {
+    lo &= m;
+    ++lo;
+  }
+  return lo;
+}
+
+int os::random() {
+  // Make updating the random seed thread safe.
+  while (true) {
+    unsigned int seed = _rand_seed;
+    unsigned int rand = random_helper(seed);
+    if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
+      return static_cast<int>(rand);
+    }
+  }
+}
+
+// The INITIALIZED state is distinguished from the SUSPENDED state because the
+// conditions in which a thread is first started are different from those in which
+// a suspension is resumed.  These differences make it hard for us to apply the
+// tougher checks when starting threads that we want to do when resuming them.
+// However, when start_thread is called as a result of Thread.start, on a Java
+// thread, the operation is synchronized on the Java Thread object.  So there
+// cannot be a race to start the thread and hence for the thread to exit while
+// we are working on it.  Non-Java threads that start Java threads either have
+// to do so in a context in which races are impossible, or should do appropriate
+// locking.
+
+void os::start_thread(Thread* thread) {
+  // guard suspend/resume
+  MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
+  OSThread* osthread = thread->osthread();
+  osthread->set_state(RUNNABLE);
+  pd_start_thread(thread);
+}
+
+void os::abort(bool dump_core) {
+  abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
+}
+
+//---------------------------------------------------------------------------
+// Helper functions for fatal error handler
+
+void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
+  assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
+
+  int cols = 0;
+  int cols_per_line = 0;
+  switch (unitsize) {
+    case 1: cols_per_line = 16; break;
+    case 2: cols_per_line = 8;  break;
+    case 4: cols_per_line = 4;  break;
+    case 8: cols_per_line = 2;  break;
+    default: return;
+  }
+
+  address p = start;
+  st->print(PTR_FORMAT ":   ", p2i(start));
+  while (p < end) {
+    switch (unitsize) {
+      case 1: st->print("%02x", *(u1*)p); break;
+      case 2: st->print("%04x", *(u2*)p); break;
+      case 4: st->print("%08x", *(u4*)p); break;
+      case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
+    }
+    p += unitsize;
+    cols++;
+    if (cols >= cols_per_line && p < end) {
+       cols = 0;
+       st->cr();
+       st->print(PTR_FORMAT ":   ", p2i(p));
+    } else {
+       st->print(" ");
+    }
+  }
+  st->cr();
+}
+
+void os::print_environment_variables(outputStream* st, const char** env_list) {
+  if (env_list) {
+    st->print_cr("Environment Variables:");
+
+    for (int i = 0; env_list[i] != NULL; i++) {
+      char *envvar = ::getenv(env_list[i]);
+      if (envvar != NULL) {
+        st->print("%s", env_list[i]);
+        st->print("=");
+        st->print_cr("%s", envvar);
+      }
+    }
+  }
+}
+
+void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
+  // cpu
+  st->print("CPU:");
+  st->print("total %d", os::processor_count());
+  // It's not safe to query number of active processors after crash
+  // st->print("(active %d)", os::active_processor_count()); but we can
+  // print the initial number of active processors.
+  // We access the raw value here because the assert in the accessor will
+  // fail if the crash occurs before initialization of this value.
+  st->print(" (initial active %d)", _initial_active_processor_count);
+  st->print(" %s", VM_Version::features_string());
+  st->cr();
+  pd_print_cpu_info(st, buf, buflen);
+}
+
+// Print a one line string summarizing the cpu, number of cores, memory, and operating system version
+void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
+  st->print("Host: ");
+#ifndef PRODUCT
+  if (get_host_name(buf, buflen)) {
+    st->print("%s, ", buf);
+  }
+#endif // PRODUCT
+  get_summary_cpu_info(buf, buflen);
+  st->print("%s, ", buf);
+  size_t mem = physical_memory()/G;
+  if (mem == 0) {  // for low memory systems
+    mem = physical_memory()/M;
+    st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
+  } else {
+    st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
+  }
+  get_summary_os_info(buf, buflen);
+  st->print_raw(buf);
+  st->cr();
+}
+
+void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
+  const int secs_per_day  = 86400;
+  const int secs_per_hour = 3600;
+  const int secs_per_min  = 60;
+
+  time_t tloc;
+  (void)time(&tloc);
+  char* timestring = ctime(&tloc);  // ctime adds newline.
+  // edit out the newline
+  char* nl = strchr(timestring, '\n');
+  if (nl != NULL) {
+    *nl = '\0';
+  }
+
+  struct tm tz;
+  if (localtime_pd(&tloc, &tz) != NULL) {
+    ::strftime(buf, buflen, "%Z", &tz);
+    st->print("Time: %s %s", timestring, buf);
+  } else {
+    st->print("Time: %s", timestring);
+  }
+
+  double t = os::elapsedTime();
+  // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
+  //       Linux. Must be a bug in glibc ? Workaround is to round "t" to int
+  //       before printf. We lost some precision, but who cares?
+  int eltime = (int)t;  // elapsed time in seconds
+
+  // print elapsed time in a human-readable format:
+  int eldays = eltime / secs_per_day;
+  int day_secs = eldays * secs_per_day;
+  int elhours = (eltime - day_secs) / secs_per_hour;
+  int hour_secs = elhours * secs_per_hour;
+  int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
+  int minute_secs = elmins * secs_per_min;
+  int elsecs = (eltime - day_secs - hour_secs - minute_secs);
+  st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
+}
+
+// moved from debug.cpp (used to be find()) but still called from there
+// The verbose parameter is only set by the debug code in one case
+void os::print_location(outputStream* st, intptr_t x, bool verbose) {
+  address addr = (address)x;
+  CodeBlob* b = CodeCache::find_blob_unsafe(addr);
+  if (b != NULL) {
+    if (b->is_buffer_blob()) {
+      // the interpreter is generated into a buffer blob
+      InterpreterCodelet* i = Interpreter::codelet_containing(addr);
+      if (i != NULL) {
+        st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
+        i->print_on(st);
+        return;
+      }
+      if (Interpreter::contains(addr)) {
+        st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
+                     " (not bytecode specific)", p2i(addr));
+        return;
+      }
+      //
+      if (AdapterHandlerLibrary::contains(b)) {
+        st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
+        AdapterHandlerLibrary::print_handler_on(st, b);
+      }
+      // the stubroutines are generated into a buffer blob
+      StubCodeDesc* d = StubCodeDesc::desc_for(addr);
+      if (d != NULL) {
+        st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
+        d->print_on(st);
+        st->cr();
+        return;
+      }
+      if (StubRoutines::contains(addr)) {
+        st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
+        return;
+      }
+      // the InlineCacheBuffer is using stubs generated into a buffer blob
+      if (InlineCacheBuffer::contains(addr)) {
+        st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
+        return;
+      }
+      VtableStub* v = VtableStubs::stub_containing(addr);
+      if (v != NULL) {
+        st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
+        v->print_on(st);
+        st->cr();
+        return;
+      }
+    }
+    nmethod* nm = b->as_nmethod_or_null();
+    if (nm != NULL) {
+      ResourceMark rm;
+      st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
+                p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
+      if (verbose) {
+        st->print(" for ");
+        nm->method()->print_value_on(st);
+      }
+      st->cr();
+      nm->print_nmethod(verbose);
+      return;
+    }
+    st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
+    b->print_on(st);
+    return;
+  }
+
+  if (Universe::heap()->is_in(addr)) {
+    HeapWord* p = Universe::heap()->block_start(addr);
+    bool print = false;
+    // If we couldn't find it it just may mean that heap wasn't parsable
+    // See if we were just given an oop directly
+    if (p != NULL && Universe::heap()->block_is_obj(p)) {
+      print = true;
+    } else if (p == NULL && oopDesc::is_oop(oop(addr))) {
+      p = (HeapWord*) addr;
+      print = true;
+    }
+    if (print) {
+      if (p == (HeapWord*) addr) {
+        st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
+      } else {
+        st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
+      }
+      oop(p)->print_on(st);
+      return;
+    }
+  } else {
+    if (Universe::heap()->is_in_reserved(addr)) {
+      st->print_cr(INTPTR_FORMAT " is an unallocated location "
+                   "in the heap", p2i(addr));
+      return;
+    }
+  }
+  if (JNIHandles::is_global_handle((jobject) addr)) {
+    st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
+    return;
+  }
+  if (JNIHandles::is_weak_global_handle((jobject) addr)) {
+    st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
+    return;
+  }
+#ifndef PRODUCT
+  // we don't keep the block list in product mode
+  if (JNIHandleBlock::any_contains((jobject) addr)) {
+    st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
+    return;
+  }
+#endif
+
+  for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
+    // Check for privilege stack
+    if (thread->privileged_stack_top() != NULL &&
+        thread->privileged_stack_top()->contains(addr)) {
+      st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
+                   "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
+      if (verbose) thread->print_on(st);
+      return;
+    }
+    // If the addr is a java thread print information about that.
+    if (addr == (address)thread) {
+      if (verbose) {
+        thread->print_on(st);
+      } else {
+        st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
+      }
+      return;
+    }
+    // If the addr is in the stack region for this thread then report that
+    // and print thread info
+    if (thread->on_local_stack(addr)) {
+      st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
+                   INTPTR_FORMAT, p2i(addr), p2i(thread));
+      if (verbose) thread->print_on(st);
+      return;
+    }
+
+  }
+
+  // Check if in metaspace and print types that have vptrs (only method now)
+  if (Metaspace::contains(addr)) {
+    if (Method::has_method_vptr((const void*)addr)) {
+      ((Method*)addr)->print_value_on(st);
+      st->cr();
+    } else {
+      // Use addr->print() from the debugger instead (not here)
+      st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
+    }
+    return;
+  }
+
+  // Try an OS specific find
+  if (os::find(addr, st)) {
+    return;
+  }
+
+  st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
+}
+
+// Looks like all platforms except IA64 can use the same function to check
+// if C stack is walkable beyond current frame. The check for fp() is not
+// necessary on Sparc, but it's harmless.
+bool os::is_first_C_frame(frame* fr) {
+#if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
+  // On IA64 we have to check if the callers bsp is still valid
+  // (i.e. within the register stack bounds).
+  // Notice: this only works for threads created by the VM and only if
+  // we walk the current stack!!! If we want to be able to walk
+  // arbitrary other threads, we'll have to somehow store the thread
+  // object in the frame.
+  Thread *thread = Thread::current();
+  if ((address)fr->fp() <=
+      thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
+    // This check is a little hacky, because on Linux the first C
+    // frame's ('start_thread') register stack frame starts at
+    // "register_stack_base + 0x48" while on HPUX, the first C frame's
+    // ('__pthread_bound_body') register stack frame seems to really
+    // start at "register_stack_base".
+    return true;
+  } else {
+    return false;
+  }
+#elif defined(IA64) && defined(_WIN32)
+  return true;
+#else
+  // Load up sp, fp, sender sp and sender fp, check for reasonable values.
+  // Check usp first, because if that's bad the other accessors may fault
+  // on some architectures.  Ditto ufp second, etc.
+  uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
+  // sp on amd can be 32 bit aligned.
+  uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
+
+  uintptr_t usp    = (uintptr_t)fr->sp();
+  if ((usp & sp_align_mask) != 0) return true;
+
+  uintptr_t ufp    = (uintptr_t)fr->fp();
+  if ((ufp & fp_align_mask) != 0) return true;
+
+  uintptr_t old_sp = (uintptr_t)fr->sender_sp();
+  if ((old_sp & sp_align_mask) != 0) return true;
+  if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
+
+  uintptr_t old_fp = (uintptr_t)fr->link();
+  if ((old_fp & fp_align_mask) != 0) return true;
+  if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
+
+  // stack grows downwards; if old_fp is below current fp or if the stack
+  // frame is too large, either the stack is corrupted or fp is not saved
+  // on stack (i.e. on x86, ebp may be used as general register). The stack
+  // is not walkable beyond current frame.
+  if (old_fp < ufp) return true;
+  if (old_fp - ufp > 64 * K) return true;
+
+  return false;
+#endif
+}
+
+
+// Set up the boot classpath.
+
+char* os::format_boot_path(const char* format_string,
+                           const char* home,
+                           int home_len,
+                           char fileSep,
+                           char pathSep) {
+    assert((fileSep == '/' && pathSep == ':') ||
+           (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
+
+    // Scan the format string to determine the length of the actual
+    // boot classpath, and handle platform dependencies as well.
+    int formatted_path_len = 0;
+    const char* p;
+    for (p = format_string; *p != 0; ++p) {
+        if (*p == '%') formatted_path_len += home_len - 1;
+        ++formatted_path_len;
+    }
+
+    char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
+    if (formatted_path == NULL) {
+        return NULL;
+    }
+
+    // Create boot classpath from format, substituting separator chars and
+    // java home directory.
+    char* q = formatted_path;
+    for (p = format_string; *p != 0; ++p) {
+        switch (*p) {
+        case '%':
+            strcpy(q, home);
+            q += home_len;
+            break;
+        case '/':
+            *q++ = fileSep;
+            break;
+        case ':':
+            *q++ = pathSep;
+            break;
+        default:
+            *q++ = *p;
+        }
+    }
+    *q = '\0';
+
+    assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
+    return formatted_path;
+}
+
+bool os::set_boot_path(char fileSep, char pathSep) {
+  const char* home = Arguments::get_java_home();
+  int home_len = (int)strlen(home);
+
+  struct stat st;
+
+  // modular image if "modules" jimage exists
+  char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
+  if (jimage == NULL) return false;
+  bool has_jimage = (os::stat(jimage, &st) == 0);
+  if (has_jimage) {
+    Arguments::set_sysclasspath(jimage, true);
+    FREE_C_HEAP_ARRAY(char, jimage);
+    return true;
+  }
+  FREE_C_HEAP_ARRAY(char, jimage);
+
+  // check if developer build with exploded modules
+  char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
+  if (base_classes == NULL) return false;
+  if (os::stat(base_classes, &st) == 0) {
+    Arguments::set_sysclasspath(base_classes, false);
+    FREE_C_HEAP_ARRAY(char, base_classes);
+    return true;
+  }
+  FREE_C_HEAP_ARRAY(char, base_classes);
+
+  return false;
+}
+
+/*
+ * Splits a path, based on its separator, the number of
+ * elements is returned back in n.
+ * It is the callers responsibility to:
+ *   a> check the value of n, and n may be 0.
+ *   b> ignore any empty path elements
+ *   c> free up the data.
+ */
+char** os::split_path(const char* path, int* n) {
+  *n = 0;
+  if (path == NULL || strlen(path) == 0) {
+    return NULL;
+  }
+  const char psepchar = *os::path_separator();
+  char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
+  if (inpath == NULL) {
+    return NULL;
+  }
+  strcpy(inpath, path);
+  int count = 1;
+  char* p = strchr(inpath, psepchar);
+  // Get a count of elements to allocate memory
+  while (p != NULL) {
+    count++;
+    p++;
+    p = strchr(p, psepchar);
+  }
+  char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
+  if (opath == NULL) {
+    return NULL;
+  }
+
+  // do the actual splitting
+  p = inpath;
+  for (int i = 0 ; i < count ; i++) {
+    size_t len = strcspn(p, os::path_separator());
+    if (len > JVM_MAXPATHLEN) {
+      return NULL;
+    }
+    // allocate the string and add terminator storage
+    char* s  = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
+    if (s == NULL) {
+      return NULL;
+    }
+    strncpy(s, p, len);
+    s[len] = '\0';
+    opath[i] = s;
+    p += len + 1;
+  }
+  FREE_C_HEAP_ARRAY(char, inpath);
+  *n = count;
+  return opath;
+}
+
+void os::set_memory_serialize_page(address page) {
+  int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
+  _mem_serialize_page = (volatile int32_t *)page;
+  // We initialize the serialization page shift count here
+  // We assume a cache line size of 64 bytes
+  assert(SerializePageShiftCount == count, "JavaThread size changed; "
+         "SerializePageShiftCount constant should be %d", count);
+  set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
+}
+
+static volatile intptr_t SerializePageLock = 0;
+
+// This method is called from signal handler when SIGSEGV occurs while the current
+// thread tries to store to the "read-only" memory serialize page during state
+// transition.
+void os::block_on_serialize_page_trap() {
+  log_debug(safepoint)("Block until the serialize page permission restored");
+
+  // When VMThread is holding the SerializePageLock during modifying the
+  // access permission of the memory serialize page, the following call
+  // will block until the permission of that page is restored to rw.
+  // Generally, it is unsafe to manipulate locks in signal handlers, but in
+  // this case, it's OK as the signal is synchronous and we know precisely when
+  // it can occur.
+  Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
+  Thread::muxRelease(&SerializePageLock);
+}
+
+// Serialize all thread state variables
+void os::serialize_thread_states() {
+  // On some platforms such as Solaris & Linux, the time duration of the page
+  // permission restoration is observed to be much longer than expected  due to
+  // scheduler starvation problem etc. To avoid the long synchronization
+  // time and expensive page trap spinning, 'SerializePageLock' is used to block
+  // the mutator thread if such case is encountered. See bug 6546278 for details.
+  Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
+  os::protect_memory((char *)os::get_memory_serialize_page(),
+                     os::vm_page_size(), MEM_PROT_READ);
+  os::protect_memory((char *)os::get_memory_serialize_page(),
+                     os::vm_page_size(), MEM_PROT_RW);
+  Thread::muxRelease(&SerializePageLock);
+}
+
+// Returns true if the current stack pointer is above the stack shadow
+// pages, false otherwise.
+bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
+  if (!thread->is_Java_thread()) return false;
+  // Check if we have StackShadowPages above the yellow zone.  This parameter
+  // is dependent on the depth of the maximum VM call stack possible from
+  // the handler for stack overflow.  'instanceof' in the stack overflow
+  // handler or a println uses at least 8k stack of VM and native code
+  // respectively.
+  const int framesize_in_bytes =
+    Interpreter::size_top_interpreter_activation(method()) * wordSize;
+
+  address limit = ((JavaThread*)thread)->stack_end() +
+                  (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
+
+  return sp > (limit + framesize_in_bytes);
+}
+
+size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
+  assert(min_pages > 0, "sanity");
+  if (UseLargePages) {
+    const size_t max_page_size = region_size / min_pages;
+
+    for (size_t i = 0; _page_sizes[i] != 0; ++i) {
+      const size_t page_size = _page_sizes[i];
+      if (page_size <= max_page_size) {
+        if (!must_be_aligned || is_aligned(region_size, page_size)) {
+          return page_size;
+        }
+      }
+    }
+  }
+
+  return vm_page_size();
+}
+
+size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
+  return page_size_for_region(region_size, min_pages, true);
+}
+
+size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
+  return page_size_for_region(region_size, min_pages, false);
+}
+
+static const char* errno_to_string (int e, bool short_text) {
+  #define ALL_SHARED_ENUMS(X) \
+    X(E2BIG, "Argument list too long") \
+    X(EACCES, "Permission denied") \
+    X(EADDRINUSE, "Address in use") \
+    X(EADDRNOTAVAIL, "Address not available") \
+    X(EAFNOSUPPORT, "Address family not supported") \
+    X(EAGAIN, "Resource unavailable, try again") \
+    X(EALREADY, "Connection already in progress") \
+    X(EBADF, "Bad file descriptor") \
+    X(EBADMSG, "Bad message") \
+    X(EBUSY, "Device or resource busy") \
+    X(ECANCELED, "Operation canceled") \
+    X(ECHILD, "No child processes") \
+    X(ECONNABORTED, "Connection aborted") \
+    X(ECONNREFUSED, "Connection refused") \
+    X(ECONNRESET, "Connection reset") \
+    X(EDEADLK, "Resource deadlock would occur") \
+    X(EDESTADDRREQ, "Destination address required") \
+    X(EDOM, "Mathematics argument out of domain of function") \
+    X(EEXIST, "File exists") \
+    X(EFAULT, "Bad address") \
+    X(EFBIG, "File too large") \
+    X(EHOSTUNREACH, "Host is unreachable") \
+    X(EIDRM, "Identifier removed") \
+    X(EILSEQ, "Illegal byte sequence") \
+    X(EINPROGRESS, "Operation in progress") \
+    X(EINTR, "Interrupted function") \
+    X(EINVAL, "Invalid argument") \
+    X(EIO, "I/O error") \
+    X(EISCONN, "Socket is connected") \
+    X(EISDIR, "Is a directory") \
+    X(ELOOP, "Too many levels of symbolic links") \
+    X(EMFILE, "Too many open files") \
+    X(EMLINK, "Too many links") \
+    X(EMSGSIZE, "Message too large") \
+    X(ENAMETOOLONG, "Filename too long") \
+    X(ENETDOWN, "Network is down") \
+    X(ENETRESET, "Connection aborted by network") \
+    X(ENETUNREACH, "Network unreachable") \
+    X(ENFILE, "Too many files open in system") \
+    X(ENOBUFS, "No buffer space available") \
+    X(ENODATA, "No message is available on the STREAM head read queue") \
+    X(ENODEV, "No such device") \
+    X(ENOENT, "No such file or directory") \
+    X(ENOEXEC, "Executable file format error") \
+    X(ENOLCK, "No locks available") \
+    X(ENOLINK, "Reserved") \
+    X(ENOMEM, "Not enough space") \
+    X(ENOMSG, "No message of the desired type") \
+    X(ENOPROTOOPT, "Protocol not available") \
+    X(ENOSPC, "No space left on device") \
+    X(ENOSR, "No STREAM resources") \
+    X(ENOSTR, "Not a STREAM") \
+    X(ENOSYS, "Function not supported") \
+    X(ENOTCONN, "The socket is not connected") \
+    X(ENOTDIR, "Not a directory") \
+    X(ENOTEMPTY, "Directory not empty") \
+    X(ENOTSOCK, "Not a socket") \
+    X(ENOTSUP, "Not supported") \
+    X(ENOTTY, "Inappropriate I/O control operation") \
+    X(ENXIO, "No such device or address") \
+    X(EOPNOTSUPP, "Operation not supported on socket") \
+    X(EOVERFLOW, "Value too large to be stored in data type") \
+    X(EPERM, "Operation not permitted") \
+    X(EPIPE, "Broken pipe") \
+    X(EPROTO, "Protocol error") \
+    X(EPROTONOSUPPORT, "Protocol not supported") \
+    X(EPROTOTYPE, "Protocol wrong type for socket") \
+    X(ERANGE, "Result too large") \
+    X(EROFS, "Read-only file system") \
+    X(ESPIPE, "Invalid seek") \
+    X(ESRCH, "No such process") \
+    X(ETIME, "Stream ioctl() timeout") \
+    X(ETIMEDOUT, "Connection timed out") \
+    X(ETXTBSY, "Text file busy") \
+    X(EWOULDBLOCK, "Operation would block") \
+    X(EXDEV, "Cross-device link")
+
+  #define DEFINE_ENTRY(e, text) { e, #e, text },
+
+  static const struct {
+    int v;
+    const char* short_text;
+    const char* long_text;
+  } table [] = {
+
+    ALL_SHARED_ENUMS(DEFINE_ENTRY)
+
+    // The following enums are not defined on all platforms.
+    #ifdef ESTALE
+    DEFINE_ENTRY(ESTALE, "Reserved")
+    #endif
+    #ifdef EDQUOT
+    DEFINE_ENTRY(EDQUOT, "Reserved")
+    #endif
+    #ifdef EMULTIHOP
+    DEFINE_ENTRY(EMULTIHOP, "Reserved")
+    #endif
+
+    // End marker.
+    { -1, "Unknown errno", "Unknown error" }
+
+  };
+
+  #undef DEFINE_ENTRY
+  #undef ALL_FLAGS
+
+  int i = 0;
+  while (table[i].v != -1 && table[i].v != e) {
+    i ++;
+  }
+
+  return short_text ? table[i].short_text : table[i].long_text;
+
+}
+
+const char* os::strerror(int e) {
+  return errno_to_string(e, false);
+}
+
+const char* os::errno_name(int e) {
+  return errno_to_string(e, true);
+}
+
+void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
+  LogTarget(Info, pagesize) log;
+  if (log.is_enabled()) {
+    LogStream out(log);
+
+    out.print("%s: ", str);
+    for (int i = 0; i < count; ++i) {
+      out.print(" " SIZE_FORMAT, page_sizes[i]);
+    }
+    out.cr();
+  }
+}
+
+#define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
+
+void os::trace_page_sizes(const char* str,
+                          const size_t region_min_size,
+                          const size_t region_max_size,
+                          const size_t page_size,
+                          const char* base,
+                          const size_t size) {
+
+  log_info(pagesize)("%s: "
+                     " min=" SIZE_FORMAT "%s"
+                     " max=" SIZE_FORMAT "%s"
+                     " base=" PTR_FORMAT
+                     " page_size=" SIZE_FORMAT "%s"
+                     " size=" SIZE_FORMAT "%s",
+                     str,
+                     trace_page_size_params(region_min_size),
+                     trace_page_size_params(region_max_size),
+                     p2i(base),
+                     trace_page_size_params(page_size),
+                     trace_page_size_params(size));
+}
+
+void os::trace_page_sizes_for_requested_size(const char* str,
+                                             const size_t requested_size,
+                                             const size_t page_size,
+                                             const size_t alignment,
+                                             const char* base,
+                                             const size_t size) {
+
+  log_info(pagesize)("%s:"
+                     " req_size=" SIZE_FORMAT "%s"
+                     " base=" PTR_FORMAT
+                     " page_size=" SIZE_FORMAT "%s"
+                     " alignment=" SIZE_FORMAT "%s"
+                     " size=" SIZE_FORMAT "%s",
+                     str,
+                     trace_page_size_params(requested_size),
+                     p2i(base),
+                     trace_page_size_params(page_size),
+                     trace_page_size_params(alignment),
+                     trace_page_size_params(size));
+}
+
+
+// This is the working definition of a server class machine:
+// >= 2 physical CPU's and >=2GB of memory, with some fuzz
+// because the graphics memory (?) sometimes masks physical memory.
+// If you want to change the definition of a server class machine
+// on some OS or platform, e.g., >=4GB on Windows platforms,
+// then you'll have to parameterize this method based on that state,
+// as was done for logical processors here, or replicate and
+// specialize this method for each platform.  (Or fix os to have
+// some inheritance structure and use subclassing.  Sigh.)
+// If you want some platform to always or never behave as a server
+// class machine, change the setting of AlwaysActAsServerClassMachine
+// and NeverActAsServerClassMachine in globals*.hpp.
+bool os::is_server_class_machine() {
+  // First check for the early returns
+  if (NeverActAsServerClassMachine) {
+    return false;
+  }
+  if (AlwaysActAsServerClassMachine) {
+    return true;
+  }
+  // Then actually look at the machine
+  bool         result            = false;
+  const unsigned int    server_processors = 2;
+  const julong server_memory     = 2UL * G;
+  // We seem not to get our full complement of memory.
+  //     We allow some part (1/8?) of the memory to be "missing",
+  //     based on the sizes of DIMMs, and maybe graphics cards.
+  const julong missing_memory   = 256UL * M;
+
+  /* Is this a server class machine? */
+  if ((os::active_processor_count() >= (int)server_processors) &&
+      (os::physical_memory() >= (server_memory - missing_memory))) {
+    const unsigned int logical_processors =
+      VM_Version::logical_processors_per_package();
+    if (logical_processors > 1) {
+      const unsigned int physical_packages =
+        os::active_processor_count() / logical_processors;
+      if (physical_packages >= server_processors) {
+        result = true;
+      }
+    } else {
+      result = true;
+    }
+  }
+  return result;
+}
+
+void os::initialize_initial_active_processor_count() {
+  assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
+  _initial_active_processor_count = active_processor_count();
+  log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
+}
+
+void os::SuspendedThreadTask::run() {
+  assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
+  internal_do_task();
+  _done = true;
+}
+
+bool os::create_stack_guard_pages(char* addr, size_t bytes) {
+  return os::pd_create_stack_guard_pages(addr, bytes);
+}
+
+char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
+  char* result = pd_reserve_memory(bytes, addr, alignment_hint);
+  if (result != NULL) {
+    MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
+  }
+
+  return result;
+}
+
+char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
+   MEMFLAGS flags) {
+  char* result = pd_reserve_memory(bytes, addr, alignment_hint);
+  if (result != NULL) {
+    MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
+    MemTracker::record_virtual_memory_type((address)result, flags);
+  }
+
+  return result;
+}
+
+char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
+  char* result = pd_attempt_reserve_memory_at(bytes, addr);
+  if (result != NULL) {
+    MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
+  }
+  return result;
+}
+
+void os::split_reserved_memory(char *base, size_t size,
+                                 size_t split, bool realloc) {
+  pd_split_reserved_memory(base, size, split, realloc);
+}
+
+bool os::commit_memory(char* addr, size_t bytes, bool executable) {
+  bool res = pd_commit_memory(addr, bytes, executable);
+  if (res) {
+    MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
+  }
+  return res;
+}
+
+bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
+                              bool executable) {
+  bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
+  if (res) {
+    MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
+  }
+  return res;
+}
+
+void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
+                               const char* mesg) {
+  pd_commit_memory_or_exit(addr, bytes, executable, mesg);
+  MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
+}
+
+void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
+                               bool executable, const char* mesg) {
+  os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
+  MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
+}
+
+bool os::uncommit_memory(char* addr, size_t bytes) {
+  bool res;
+  if (MemTracker::tracking_level() > NMT_minimal) {
+    Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
+    res = pd_uncommit_memory(addr, bytes);
+    if (res) {
+      tkr.record((address)addr, bytes);
+    }
+  } else {
+    res = pd_uncommit_memory(addr, bytes);
+  }
+  return res;
+}
+
+bool os::release_memory(char* addr, size_t bytes) {
+  bool res;
+  if (MemTracker::tracking_level() > NMT_minimal) {
+    Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
+    res = pd_release_memory(addr, bytes);
+    if (res) {
+      tkr.record((address)addr, bytes);
+    }
+  } else {
+    res = pd_release_memory(addr, bytes);
+  }
+  return res;
+}
+
+void os::pretouch_memory(void* start, void* end, size_t page_size) {
+  for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
+    *p = 0;
+  }
+}
+
+char* os::map_memory(int fd, const char* file_name, size_t file_offset,
+                           char *addr, size_t bytes, bool read_only,
+                           bool allow_exec) {
+  char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
+  if (result != NULL) {
+    MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
+  }
+  return result;
+}
+
+char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
+                             char *addr, size_t bytes, bool read_only,
+                             bool allow_exec) {
+  return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
+                    read_only, allow_exec);
+}
+
+bool os::unmap_memory(char *addr, size_t bytes) {
+  bool result;
+  if (MemTracker::tracking_level() > NMT_minimal) {
+    Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
+    result = pd_unmap_memory(addr, bytes);
+    if (result) {
+      tkr.record((address)addr, bytes);
+    }
+  } else {
+    result = pd_unmap_memory(addr, bytes);
+  }
+  return result;
+}
+
+void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
+  pd_free_memory(addr, bytes, alignment_hint);
+}
+
+void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
+  pd_realign_memory(addr, bytes, alignment_hint);
+}
+
+#ifndef _WINDOWS
+/* try to switch state from state "from" to state "to"
+ * returns the state set after the method is complete
+ */
+os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
+                                                         os::SuspendResume::State to)
+{
+  os::SuspendResume::State result =
+    (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
+  if (result == from) {
+    // success
+    return to;
+  }
+  return result;
+}
+#endif