Merge up to 8597 to experimental/gc from the bleeding edge.

src/platform-linux.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 668 matching lines @@
 }
 
 
 class Thread::PlatformData : public Malloced {
  public:
   PlatformData() : thread_(kNoThread) {}
 
   pthread_t thread_;  // Thread handle for pthread.
 };
 
-Thread::Thread(Isolate* isolate, const Options& options)
+Thread::Thread(const Options& options)
     : data_(new PlatformData()),
-      isolate_(isolate),
       stack_size_(options.stack_size) {
   set_name(options.name);
 }
 
 
-Thread::Thread(Isolate* isolate, const char* name)
+Thread::Thread(const char* name)
     : data_(new PlatformData()),
-      isolate_(isolate),
       stack_size_(0) {
   set_name(name);
 }
 
 
 Thread::~Thread() {
   delete data_;
 }
 
 
 static void* ThreadEntry(void* arg) {
   Thread* thread = reinterpret_cast<Thread*>(arg);
   // This is also initialized by the first argument to pthread_create() but we
   // don't know which thread will run first (the original thread or the new
   // one) so we initialize it here too.
   prctl(PR_SET_NAME,
         reinterpret_cast<unsigned long>(thread->name()),  // NOLINT
         0, 0, 0);
   thread->data()->thread_ = pthread_self();
   ASSERT(thread->data()->thread_ != kNoThread);
-  Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate());
   thread->Run();
   return NULL;
 }
 
 
 void Thread::set_name(const char* name) {
   strncpy(name_, name, sizeof(name_));
   name_[sizeof(name_) - 1] = '\0';
 }
 
@@ skipping 45 matching lines @@
 }
 
 
 void Thread::YieldCPU() {
   sched_yield();
 }
 
 
 class LinuxMutex : public Mutex {
  public:
-
   LinuxMutex() {
     pthread_mutexattr_t attrs;
     int result = pthread_mutexattr_init(&attrs);
     ASSERT(result == 0);
     result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
     ASSERT(result == 0);
     result = pthread_mutex_init(&mutex_, &attrs);
     ASSERT(result == 0);
   }
 
@@ skipping 204 matching lines @@
 
 
 class SignalSender : public Thread {
  public:
   enum SleepInterval {
     HALF_INTERVAL,
     FULL_INTERVAL
   };
 
   explicit SignalSender(int interval)
-      : Thread(NULL, "SignalSender"),
+      : Thread("SignalSender"),
         vm_tgid_(getpid()),
         interval_(interval) {}
 
+  static void InstallSignalHandler() {
+    struct sigaction sa;
+    sa.sa_sigaction = ProfilerSignalHandler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART | SA_SIGINFO;
+    signal_handler_installed_ =
+        (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
+  }
+
+  static void RestoreSignalHandler() {
+    if (signal_handler_installed_) {
+      sigaction(SIGPROF, &old_signal_handler_, 0);
+      signal_handler_installed_ = false;
+    }
+  }
+
   static void AddActiveSampler(Sampler* sampler) {
     ScopedLock lock(mutex_);
     SamplerRegistry::AddActiveSampler(sampler);
     if (instance_ == NULL) {
-      // Install a signal handler.
-      struct sigaction sa;
-      sa.sa_sigaction = ProfilerSignalHandler;
-      sigemptyset(&sa.sa_mask);
-      sa.sa_flags = SA_RESTART | SA_SIGINFO;
-      signal_handler_installed_ =
-          (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
-
-      // Start a thread that sends SIGPROF signal to VM threads.
+      // Start a thread that will send SIGPROF signal to VM threads,
+      // when CPU profiling will be enabled.
       instance_ = new SignalSender(sampler->interval());
       instance_->Start();
     } else {
       ASSERT(instance_->interval_ == sampler->interval());
     }
   }
 
   static void RemoveActiveSampler(Sampler* sampler) {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::WakeUpRuntimeProfilerThreadBeforeShutdown();
-      instance_->Join();
+      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
       delete instance_;
       instance_ = NULL;
-
-      // Restore the old signal handler.
-      if (signal_handler_installed_) {
-        sigaction(SIGPROF, &old_signal_handler_, 0);
-        signal_handler_installed_ = false;
-      }
+      RestoreSignalHandler();
     }
   }
 
   // Implement Thread::Run().
   virtual void Run() {
     SamplerRegistry::State state;
     while ((state = SamplerRegistry::GetState()) !=
            SamplerRegistry::HAS_NO_SAMPLERS) {
       bool cpu_profiling_enabled =
           (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
       bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
+      if (cpu_profiling_enabled && !signal_handler_installed_) {
+        InstallSignalHandler();
+      } else if (!cpu_profiling_enabled && signal_handler_installed_) {
+        RestoreSignalHandler();
+      }
       // When CPU profiling is enabled both JavaScript and C++ code is
       // profiled. We must not suspend.
       if (!cpu_profiling_enabled) {
         if (rate_limiter_.SuspendIfNecessary()) continue;
       }
       if (cpu_profiling_enabled && runtime_profiler_enabled) {
         if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
           return;
         }
         Sleep(HALF_INTERVAL);
@@ skipping 103 matching lines @@
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal