Remove profiler thread related methods from RuntimeProfiler

Now that V8 doesn't use sampling thread for optimizations
the methods can be removed.

BUG=None

Review URL: https://codereview.chromium.org/14057003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14214 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/isolate.cc

@@ -1556,9 +1556,6 @@ Handle<Context> Isolate::GetCallingNativeContext() {
 
 
 char* Isolate::ArchiveThread(char* to) {
-  if (RuntimeProfiler::IsEnabled() && current_vm_state() == JS) {
-    RuntimeProfiler::IsolateExitedJS(this);
-  }
   memcpy(to, reinterpret_cast<char*>(thread_local_top()),
          sizeof(ThreadLocalTop));
   InitializeThreadLocal();
@@ -1581,9 +1578,6 @@ char* Isolate::RestoreThread(char* from) {
   thread_local_top()->simulator_ = Simulator::current(this);
 #endif
 #endif
-  if (RuntimeProfiler::IsEnabled() && current_vm_state() == JS) {
-    RuntimeProfiler::IsolateEnteredJS(this);
-  }
   ASSERT(context() == NULL || context()->IsContext());
   return from + sizeof(ThreadLocalTop);
 }

src/isolate.h

@@ -1027,23 +1027,6 @@ class Isolate {
   }
 
   void SetCurrentVMState(StateTag state) {
-    if (RuntimeProfiler::IsEnabled()) {
-      // Make sure thread local top is initialized.
-      ASSERT(thread_local_top_.isolate_ == this);
-      StateTag current_state = thread_local_top_.current_vm_state_;
-      if (current_state != JS && state == JS) {
-        // Non-JS -> JS transition.
-        RuntimeProfiler::IsolateEnteredJS(this);
-      } else if (current_state == JS && state != JS) {
-        // JS -> non-JS transition.
-        RuntimeProfiler::IsolateExitedJS(this);
-      } else {
-        // Other types of state transitions are not interesting to the
-        // runtime profiler, because they don't affect whether we're
-        // in JS or not.
-        ASSERT((current_state == JS) == (state == JS));
-      }
-    }
     thread_local_top_.current_vm_state_ = state;
   }
 

src/platform-cygwin.cc

@@ -650,7 +650,7 @@ class SamplerThread : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
     }
@@ -665,8 +665,6 @@ class SamplerThread : public Thread {
       // profiled. We must not suspend.
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
       }
       OS::Sleep(interval_);
     }

src/platform-freebsd.cc

@@ -776,7 +776,7 @@ class SignalSender : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
 
@@ -797,8 +797,6 @@ class SignalSender : public Thread {
       // profiled. We must not suspend.
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
       }
       Sleep();  // TODO(svenpanne) Figure out if OS:Sleep(interval_) is enough.
     }

src/platform-linux.cc

@@ -1194,7 +1194,7 @@ class SignalSender : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
       RestoreSignalHandler();
@@ -1213,7 +1213,6 @@ class SignalSender : public Thread {
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
       } else {
         if (signal_handler_installed_) RestoreSignalHandler();
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
       }
       Sleep();  // TODO(svenpanne) Figure out if OS:Sleep(interval_) is enough.
     }

src/platform-macos.cc

@@ -787,7 +787,7 @@ class SamplerThread : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
     }
@@ -802,8 +802,6 @@ class SamplerThread : public Thread {
       // profiled. We must not suspend.
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
       }
       OS::Sleep(interval_);
     }

src/platform-openbsd.cc

@@ -838,7 +838,7 @@ class SignalSender : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
       RestoreSignalHandler();
@@ -855,9 +855,8 @@ class SignalSender : public Thread {
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         if (!signal_handler_installed_) InstallSignalHandler();
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (signal_handler_installed_) RestoreSignalHandler();
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
+      } else if (signal_handler_installed_) {
+        RestoreSignalHandler();
       }
       Sleep();  // TODO(svenpanne) Figure out if OS:Sleep(interval_) is enough.
     }

src/platform-solaris.cc

@@ -754,7 +754,7 @@ class SignalSender : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
       RestoreSignalHandler();
@@ -771,9 +771,8 @@ class SignalSender : public Thread {
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         if (!signal_handler_installed_) InstallSignalHandler();
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (signal_handler_installed_) RestoreSignalHandler();
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
+      } else if (signal_handler_installed_) {
+        RestoreSignalHandler();
       }
       Sleep();  // TODO(svenpanne) Figure out if OS:Sleep(interval_) is enough.
     }

src/platform-win32.cc

@@ -2027,7 +2027,7 @@ class SamplerThread : public Thread {
     ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
-      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      instance_->Join();
       delete instance_;
       instance_ = NULL;
     }
@@ -2042,8 +2042,6 @@ class SamplerThread : public Thread {
       // profiled. We must not suspend.
       if (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS) {
         SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this);
-      } else {
-        if (RuntimeProfiler::WaitForSomeIsolateToEnterJS()) continue;
       }
       OS::Sleep(interval_);
     }

src/runtime-profiler.cc

@@ -86,17 +86,6 @@ static const int kMaxSizeEarlyOpt =
     5 * FullCodeGenerator::kBackEdgeDistanceUnit;
 
 
-Atomic32 RuntimeProfiler::state_ = 0;
-
-// TODO(isolates): Clean up the semaphore when it is no longer required.
-static LazySemaphore<0>::type semaphore = LAZY_SEMAPHORE_INITIALIZER;
-
-#ifdef DEBUG
-bool RuntimeProfiler::has_been_globally_set_up_ = false;
-#endif
-bool RuntimeProfiler::enabled_ = false;
-
-
 RuntimeProfiler::RuntimeProfiler(Isolate* isolate)
     : isolate_(isolate),
       sampler_threshold_(kSamplerThresholdInit),
@@ -110,15 +99,6 @@ RuntimeProfiler::RuntimeProfiler(Isolate* isolate)
 }
 
 
-void RuntimeProfiler::GlobalSetUp() {
-  ASSERT(!has_been_globally_set_up_);
-  enabled_ = V8::UseCrankshaft() && FLAG_opt;
-#ifdef DEBUG
-  has_been_globally_set_up_ = true;
-#endif
-}
-
-
 static void GetICCounts(JSFunction* function,
                         int* ic_with_type_info_count,
                         int* ic_total_count,
@@ -386,7 +366,6 @@ void RuntimeProfiler::OptimizeNow() {
 
 
 void RuntimeProfiler::SetUp() {
-  ASSERT(has_been_globally_set_up_);
   if (!FLAG_watch_ic_patching) {
     ClearSampleBuffer();
   }
@@ -429,48 +408,6 @@ void RuntimeProfiler::UpdateSamplesAfterScavenge() {
 }
 
 
-void RuntimeProfiler::HandleWakeUp(Isolate* isolate) {
-  // The profiler thread must still be waiting.
-  ASSERT(NoBarrier_Load(&state_) >= 0);
-  // In IsolateEnteredJS we have already incremented the counter and
-  // undid the decrement done by the profiler thread. Increment again
-  // to get the right count of active isolates.
-  NoBarrier_AtomicIncrement(&state_, 1);
-  semaphore.Pointer()->Signal();
-}
-
-
-bool RuntimeProfiler::WaitForSomeIsolateToEnterJS() {
-  Atomic32 old_state = NoBarrier_CompareAndSwap(&state_, 0, -1);
-  ASSERT(old_state >= -1);
-  if (old_state != 0) return false;
-  semaphore.Pointer()->Wait();
-  return true;
-}
-
-
-void RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(Thread* thread) {
-  // Do a fake increment. If the profiler is waiting on the semaphore,
-  // the returned state is 0, which can be left as an initial state in
-  // case profiling is restarted later. If the profiler is not
-  // waiting, the increment will prevent it from waiting, but has to
-  // be undone after the profiler is stopped.
-  Atomic32 new_state = NoBarrier_AtomicIncrement(&state_, 1);
-  ASSERT(new_state >= 0);
-  if (new_state == 0) {
-    // The profiler thread is waiting. Wake it up. It must check for
-    // stop conditions before attempting to wait again.
-    semaphore.Pointer()->Signal();
-  }
-  thread->Join();
-  // The profiler thread is now stopped. Undo the increment in case it
-  // was not waiting.
-  if (new_state != 0) {
-    NoBarrier_AtomicIncrement(&state_, -1);
-  }
-}
-
-
 void RuntimeProfiler::RemoveDeadSamples() {
   for (int i = 0; i < kSamplerWindowSize; i++) {
     Object* function = sampler_window_[i];

src/runtime-profiler.h

@@ -43,13 +43,6 @@ class RuntimeProfiler {
  public:
   explicit RuntimeProfiler(Isolate* isolate);
 
-  static void GlobalSetUp();
-
-  static inline bool IsEnabled() {
-    ASSERT(has_been_globally_set_up_);
-    return enabled_;
-  }
-
   void OptimizeNow();
 
   void SetUp();
@@ -63,26 +56,6 @@ class RuntimeProfiler {
 
   // Rate limiting support.
 
-  // VM thread interface.
-  //
-  // Called by isolates when their states change.
-  static inline void IsolateEnteredJS(Isolate* isolate);
-  static inline void IsolateExitedJS(Isolate* isolate);
-
-  // Profiler thread interface.
-  //
-  // WaitForSomeIsolateToEnterJS():
-  // When no isolates are running JavaScript code for some time the
-  // profiler thread suspends itself by calling the wait function. The
-  // wait function returns true after it waited or false immediately.
-  // While the function was waiting the profiler may have been
-  // disabled so it *must check* whether it is allowed to continue.
-  static bool WaitForSomeIsolateToEnterJS();
-
-  // Stops the runtime profiler thread when profiling support is being
-  // turned off.
-  static void StopRuntimeProfilerThreadBeforeShutdown(Thread* thread);
-
   void UpdateSamplesAfterScavenge();
   void RemoveDeadSamples();
   void UpdateSamplesAfterCompact(ObjectVisitor* visitor);
@@ -92,8 +65,6 @@ class RuntimeProfiler {
  private:
   static const int kSamplerWindowSize = 16;
 
-  static void HandleWakeUp(Isolate* isolate);
-
   void Optimize(JSFunction* function, const char* reason);
 
   void ClearSampleBuffer();
@@ -116,39 +87,8 @@ class RuntimeProfiler {
 
   bool any_ic_changed_;
   bool code_generated_;
-
-  // Possible state values:
-  //   -1            => the profiler thread is waiting on the semaphore
-  //   0 or positive => the number of isolates running JavaScript code.
-  static Atomic32 state_;
-
-#ifdef DEBUG
-  static bool has_been_globally_set_up_;
-#endif
-  static bool enabled_;
 };
 
-
-// Implementation of RuntimeProfiler inline functions.
-
-void RuntimeProfiler::IsolateEnteredJS(Isolate* isolate) {
-  Atomic32 new_state = NoBarrier_AtomicIncrement(&state_, 1);
-  if (new_state == 0) {
-    // Just incremented from -1 to 0. -1 can only be set by the
-    // profiler thread before it suspends itself and starts waiting on
-    // the semaphore.
-    HandleWakeUp(isolate);
-  }
-  ASSERT(new_state >= 0);
-}
-
-
-void RuntimeProfiler::IsolateExitedJS(Isolate* isolate) {
-  Atomic32 new_state = NoBarrier_AtomicIncrement(&state_, -1);
-  ASSERT(new_state >= 0);
-  USE(new_state);
-}
-
 } }  // namespace v8::internal
 
 #endif  // V8_RUNTIME_PROFILER_H_

src/v8.cc

@@ -275,7 +275,6 @@ void V8::InitializeOncePerProcessImpl() {
       && !Serializer::enabled()
       && CPU::SupportsCrankshaft();
   OS::PostSetUp();
-  RuntimeProfiler::GlobalSetUp();
   ElementsAccessor::InitializeOncePerProcess();
   LOperand::SetUpCaches();
   SetUpJSCallerSavedCodeData();