Split Ticker into two samplers.

src/profiler/cpu-profiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/profiler/cpu-profiler.h"
 
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/frames-inl.h"
 #include "src/locked-queue-inl.h"
 #include "src/log-inl.h"
 #include "src/profiler/cpu-profiler-inl.h"
 #include "src/vm-state-inl.h"
 
 #include "include/v8-profiler.h"
 
 namespace v8 {
 namespace internal {
 
 static const int kProfilerStackSize = 64 * KB;
 
+class CpuSampler : public sampler::Sampler {
+ public:
+  CpuSampler(Isolate* isolate, ProfilerEventsProcessor* processor)
+      : sampler::Sampler(reinterpret_cast<v8::Isolate*>(isolate)),
+        processor_(processor) {}
 
-ProfilerEventsProcessor::ProfilerEventsProcessor(ProfileGenerator* generator,
-                                                 sampler::Sampler* sampler,
+  void SampleStack(const v8::RegisterState& state) override {
+    v8::Isolate* v8_isolate = isolate();
+    Isolate* i_isolate = reinterpret_cast<Isolate*>(v8_isolate);
+    v8::RegisterState regs;
+#if defined(USE_SIMULATOR)
+    if (!SimulatorHelper::FillRegisters(i_isolate, &regs)) return;
+#else
+    regs.pc = state.pc;

[alph, 2016/06/30 21:25:10]

Why don't you want keep it as it was before?
So in the simulator case you don't need const_cast and in the regular case when
we need speed there's no copying. I mean:

#if defined(USE_SIMULATOR)
  v8::RegisterState regs;
  if (!SimulatorHelper::FillRegisters(i_isolate, &regs)) return;
#else
  const v8::RegisterState& regs = state;
#endif

[lpy, 2016/06/30 21:34:45]

Done.

+    regs.fp = state.fp;
+    regs.sp = state.sp;
+#endif
+    TickSample* sample = processor_->StartTickSample();
+    if (sample == NULL) return;
+    sample->Init(i_isolate, regs, TickSample::kIncludeCEntryFrame, true);
+    if (is_counting_samples_ && !sample->timestamp.IsNull()) {
+      if (sample->state == JS) ++js_sample_count_;
+      if (sample->state == EXTERNAL) ++external_sample_count_;
+    }
+    processor_->FinishTickSample();
+  }
+
+ private:
+  ProfilerEventsProcessor* processor_;
+};
+
+ProfilerEventsProcessor::ProfilerEventsProcessor(Isolate* isolate,
+                                                 ProfileGenerator* generator,
                                                  base::TimeDelta period)
     : Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)),
       generator_(generator),
-      sampler_(sampler),
+      sampler_(new CpuSampler(isolate, this)),
       running_(1),
       period_(period),
       last_code_event_id_(0),
-      last_processed_code_event_id_(0) {}
+      last_processed_code_event_id_(0) {
+  sampler_->IncreaseProfilingDepth();
+}
 
-
-ProfilerEventsProcessor::~ProfilerEventsProcessor() {}
-
+ProfilerEventsProcessor::~ProfilerEventsProcessor() {
+  sampler_->DecreaseProfilingDepth();
+}
 
 void ProfilerEventsProcessor::Enqueue(const CodeEventsContainer& event) {
   event.generic.order = last_code_event_id_.Increment(1);
   events_buffer_.Enqueue(event);
 }
 
 
 void ProfilerEventsProcessor::AddDeoptStack(Isolate* isolate, Address from,
                                             int fp_to_sp_delta) {
   TickSampleEventRecord record(last_code_event_id_.Value());
@@ skipping 229 matching lines @@
 
 void CpuProfiler::StartProcessorIfNotStarted() {
   if (processor_) {
     processor_->AddCurrentStack(isolate_);
     return;
   }
   Logger* logger = isolate_->logger();
   // Disable logging when using the new implementation.
   saved_is_logging_ = logger->is_logging_;
   logger->is_logging_ = false;
-  sampler::Sampler* sampler = logger->sampler();
   generator_.reset(new ProfileGenerator(profiles_.get()));
-  processor_.reset(new ProfilerEventsProcessor(generator_.get(), sampler,
+  processor_.reset(new ProfilerEventsProcessor(isolate_, generator_.get(),
                                                sampling_interval_));
   logger->SetUpProfilerListener();
   ProfilerListener* profiler_listener = logger->profiler_listener();
   profiler_listener->AddObserver(this);
   is_profiling_ = true;
   isolate_->set_is_profiling(true);
   // Enumerate stuff we already have in the heap.
   DCHECK(isolate_->heap()->HasBeenSetUp());
   if (!FLAG_prof_browser_mode) {
     logger->LogCodeObjects();
   }
   logger->LogCompiledFunctions();
   logger->LogAccessorCallbacks();
   LogBuiltins();
   // Enable stack sampling.
-  sampler->SetHasProcessingThread(true);
-  sampler->IncreaseProfilingDepth();
   processor_->AddCurrentStack(isolate_);
   processor_->StartSynchronously();
 }
 
 
 CpuProfile* CpuProfiler::StopProfiling(const char* title) {
   if (!is_profiling_) return nullptr;
   StopProcessorIfLastProfile(title);
   CpuProfile* result = profiles_->StopProfiling(title);
   if (result) {
@@ skipping 13 matching lines @@
 
 void CpuProfiler::StopProcessorIfLastProfile(const char* title) {
   if (profiles_->IsLastProfile(title)) {
     StopProcessor();
   }
 }
 
 
 void CpuProfiler::StopProcessor() {
   Logger* logger = isolate_->logger();
-  sampler::Sampler* sampler =
-      reinterpret_cast<sampler::Sampler*>(logger->ticker_);
   is_profiling_ = false;
   isolate_->set_is_profiling(false);
   ProfilerListener* profiler_listener = logger->profiler_listener();
   profiler_listener->RemoveObserver(this);
   processor_->StopSynchronously();
   logger->TearDownProfilerListener();
   processor_.reset();
   generator_.reset();
-  sampler->SetHasProcessingThread(false);
-  sampler->DecreaseProfilingDepth();
   logger->is_logging_ = saved_is_logging_;
 }
 
 
 void CpuProfiler::LogBuiltins() {
   Builtins* builtins = isolate_->builtins();
   DCHECK(builtins->is_initialized());
   for (int i = 0; i < Builtins::builtin_count; i++) {
     CodeEventsContainer evt_rec(CodeEventRecord::REPORT_BUILTIN);
     ReportBuiltinEventRecord* rec = &evt_rec.ReportBuiltinEventRecord_;
     Builtins::Name id = static_cast<Builtins::Name>(i);
     rec->start = builtins->builtin(id)->address();
     rec->builtin_id = id;
     processor_->Enqueue(evt_rec);
   }
 }
 
 }  // namespace internal
 }  // namespace v8