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

src/platform-solaris.cc

Index: src/platform-solaris.cc
===================================================================
--- src/platform-solaris.cc	(revision 8618)
+++ src/platform-solaris.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright 2006-2009 the V8 project authors. All rights reserved.
+// 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:
@@ -88,6 +88,7 @@
 }
 
 
+static Mutex* limit_mutex = NULL;
 void OS::Setup() {
   // Seed the random number generator.
   // Convert the current time to a 64-bit integer first, before converting it
@@ -96,6 +97,7 @@
   // call this setup code within the same millisecond.
   uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
   srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
 }
 
 
@@ -105,7 +107,8 @@
 
 
 int OS::ActivationFrameAlignment() {
-  return STACK_ALIGN;
+  // GCC generates code that requires 16 byte alignment such as movdqa.
+  return Max(STACK_ALIGN, 16);
 }
 
 
@@ -144,6 +147,9 @@
 
 
 static void UpdateAllocatedSpaceLimits(void* address, int size) {
+  ASSERT(limit_mutex != NULL);
+  ScopedLock lock(limit_mutex);
+
   lowest_ever_allocated = Min(lowest_ever_allocated, address);
   highest_ever_allocated =
       Max(highest_ever_allocated,
@@ -380,17 +386,15 @@
   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);
 }
@@ -408,7 +412,6 @@
   // one) so we initialize it here too.
   thread->data()->thread_ = pthread_self();
   ASSERT(thread->data()->thread_ != kNoThread);
-  Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate());
   thread->Run();
   return NULL;
 }
@@ -588,78 +591,171 @@
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
-static Sampler* active_sampler_ = NULL;
-static pthread_t vm_tid_ = 0;
-
-
 static pthread_t GetThreadID() {
   return pthread_self();
 }
 
-
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
   USE(info);
   if (signal != SIGPROF) return;
-  if (active_sampler_ == NULL || !active_sampler_->IsActive()) return;
-  if (vm_tid_ != GetThreadID()) return;
+  Isolate* isolate = Isolate::UncheckedCurrent();
+  if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
+    // We require a fully initialized and entered isolate.
+    return;
+  }
+  if (v8::Locker::IsActive() &&
+      !isolate->thread_manager()->IsLockedByCurrentThread()) {
+    return;
+  }
 
+  Sampler* sampler = isolate->logger()->sampler();
+  if (sampler == NULL || !sampler->IsActive()) return;
+
   TickSample sample_obj;
-  TickSample* sample = CpuProfiler::TickSampleEvent();
+  TickSample* sample = CpuProfiler::TickSampleEvent(isolate);
   if (sample == NULL) sample = &sample_obj;
 
   // Extracting the sample from the context is extremely machine dependent.
   ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
   mcontext_t& mcontext = ucontext->uc_mcontext;
-  sample->state = Top::current_vm_state();
+  sample->state = isolate->current_vm_state();
 
   sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_PC]);
   sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_SP]);
   sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_FP]);
 
-  active_sampler_->SampleStack(sample);
-  active_sampler_->Tick(sample);
+  sampler->SampleStack(sample);
+  sampler->Tick(sample);
 }
 
-
 class Sampler::PlatformData : public Malloced {
  public:
+  PlatformData() : vm_tid_(GetThreadID()) {}
+
+  pthread_t vm_tid() const { return vm_tid_; }
+
+ private:
+  pthread_t vm_tid_;
+};
+
+
+class SignalSender : public Thread {
+ public:
   enum SleepInterval {
-    FULL_INTERVAL,
-    HALF_INTERVAL
+    HALF_INTERVAL,
+    FULL_INTERVAL
   };
 
-  explicit PlatformData(Sampler* sampler)
-      : sampler_(sampler),
-        signal_handler_installed_(false),
-        vm_tgid_(getpid()),
-        signal_sender_launched_(false) {
+  explicit SignalSender(int interval)
+      : Thread("SignalSender"),
+        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);
   }
 
-  void SignalSender() {
-    while (sampler_->IsActive()) {
-      if (rate_limiter_.SuspendIfNecessary()) continue;
-      if (sampler_->IsProfiling() && RuntimeProfiler::IsEnabled()) {
-        SendProfilingSignal();
+  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) {
+      // 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::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      delete instance_;
+      instance_ = NULL;
+      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);
-        RuntimeProfiler::NotifyTick();
+        if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
+          return;
+        }
         Sleep(HALF_INTERVAL);
       } else {
-        if (sampler_->IsProfiling()) SendProfilingSignal();
-        if (RuntimeProfiler::IsEnabled()) RuntimeProfiler::NotifyTick();
+        if (cpu_profiling_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile,
+                                                      this)) {
+            return;
+          }
+        }
+        if (runtime_profiler_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile,
+                                                      NULL)) {
+            return;
+          }
+        }
         Sleep(FULL_INTERVAL);
       }
     }
   }
 
-  void SendProfilingSignal() {
+  static void DoCpuProfile(Sampler* sampler, void* raw_sender) {
+    if (!sampler->IsProfiling()) return;
+    SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender);
+    sender->SendProfilingSignal(sampler->platform_data()->vm_tid());
+  }
+
+  static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
+    if (!sampler->isolate()->IsInitialized()) return;
+    sampler->isolate()->runtime_profiler()->NotifyTick();
+  }
+
+  void SendProfilingSignal(pthread_t tid) {
     if (!signal_handler_installed_) return;
-    pthread_kill(vm_tid_, SIGPROF);
+    pthread_kill(tid, SIGPROF);
   }
 
   void Sleep(SleepInterval full_or_half) {
     // Convert ms to us and subtract 100 us to compensate delays
     // occuring during signal delivery.
-    useconds_t interval = sampler_->interval_ * 1000 - 100;
+    useconds_t interval = interval_ * 1000 - 100;
     if (full_or_half == HALF_INTERVAL) interval /= 2;
     int result = usleep(interval);
 #ifdef DEBUG
@@ -674,87 +770,51 @@
     USE(result);
   }
 
-  Sampler* sampler_;
-  bool signal_handler_installed_;
-  struct sigaction old_signal_handler_;
-  int vm_tgid_;
-  bool signal_sender_launched_;
-  pthread_t signal_sender_thread_;
+  const int interval_;
   RuntimeProfilerRateLimiter rate_limiter_;
+
+  // Protects the process wide state below.
+  static Mutex* mutex_;
+  static SignalSender* instance_;
+  static bool signal_handler_installed_;
+  static struct sigaction old_signal_handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(SignalSender);
 };
 
+Mutex* SignalSender::mutex_ = OS::CreateMutex();
+SignalSender* SignalSender::instance_ = NULL;
+struct sigaction SignalSender::old_signal_handler_;
+bool SignalSender::signal_handler_installed_ = false;
 
-static void* SenderEntry(void* arg) {
-  Sampler::PlatformData* data =
-      reinterpret_cast<Sampler::PlatformData*>(arg);
-  data->SignalSender();
-  return 0;
-}
 
-
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),
       profiling_(false),
       active_(false),
       samples_taken_(0) {
-  data_ = new PlatformData(this);
+  data_ = new PlatformData;
 }
 
 
 Sampler::~Sampler() {
-  ASSERT(!data_->signal_sender_launched_);
+  ASSERT(!IsActive());
   delete data_;
 }
 
 
 void Sampler::Start() {
-  // There can only be one active sampler at the time on POSIX
-  // platforms.
   ASSERT(!IsActive());
-  vm_tid_ = GetThreadID();
-
-  // Request profiling signals.
-  struct sigaction sa;
-  sa.sa_sigaction = ProfilerSignalHandler;
-  sigemptyset(&sa.sa_mask);
-  sa.sa_flags = SA_RESTART | SA_SIGINFO;
-  data_->signal_handler_installed_ =
-      sigaction(SIGPROF, &sa, &data_->old_signal_handler_) == 0;
-
-  // Start a thread that sends SIGPROF signal to VM thread.
-  // Sending the signal ourselves instead of relying on itimer provides
-  // much better accuracy.
   SetActive(true);
-  if (pthread_create(
-          &data_->signal_sender_thread_, NULL, SenderEntry, data_) == 0) {
-    data_->signal_sender_launched_ = true;
-  }
-
-  // Set this sampler as the active sampler.
-  active_sampler_ = this;
+  SignalSender::AddActiveSampler(this);
 }
 
 
 void Sampler::Stop() {
+  ASSERT(IsActive());
+  SignalSender::RemoveActiveSampler(this);
   SetActive(false);
-
-  // Wait for signal sender termination (it will exit after setting
-  // active_ to false).
-  if (data_->signal_sender_launched_) {
-    Top::WakeUpRuntimeProfilerThreadBeforeShutdown();
-    pthread_join(data_->signal_sender_thread_, NULL);
-    data_->signal_sender_launched_ = false;
-  }
-
-  // Restore old signal handler
-  if (data_->signal_handler_installed_) {
-    sigaction(SIGPROF, &data_->old_signal_handler_, 0);
-    data_->signal_handler_installed_ = false;
-  }
-
-  // This sampler is no longer the active sampler.
-  active_sampler_ = NULL;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING