Allow configuring CPU profiler sampling interval using public API

src/cpu-profiler.cc

 // Copyright 2012 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 345 matching lines @@
       profiles_->GetName(name),
       "set ");
   rec->size = 1;
   rec->shared = NULL;
   processor_->Enqueue(evt_rec);
 }
 
 
 CpuProfiler::CpuProfiler(Isolate* isolate)
     : isolate_(isolate),
+      sampling_interval_(TimeDelta::FromMicroseconds(
+          FLAG_cpu_profiler_sampling_interval)),
       profiles_(new CpuProfilesCollection()),
       next_profile_uid_(1),
       generator_(NULL),
       processor_(NULL),
       is_profiling_(false) {
 }
 
 
 CpuProfiler::CpuProfiler(Isolate* isolate,
                          CpuProfilesCollection* test_profiles,
                          ProfileGenerator* test_generator,
                          ProfilerEventsProcessor* test_processor)
     : isolate_(isolate),
+      sampling_interval_(TimeDelta::FromMicroseconds(
+          FLAG_cpu_profiler_sampling_interval)),
       profiles_(test_profiles),
       next_profile_uid_(1),
       generator_(test_generator),
       processor_(test_processor),
       is_profiling_(false) {
 }
 
 
 CpuProfiler::~CpuProfiler() {
   ASSERT(!is_profiling_);
   delete profiles_;
 }
 
 
+void CpuProfiler::set_sampling_interval(TimeDelta value) {
+  ASSERT(!is_profiling_);
+  sampling_interval_ = value;
+}
+
+
 void CpuProfiler::ResetProfiles() {
   delete profiles_;
   profiles_ = new CpuProfilesCollection();
 }
 
 
 void CpuProfiler::StartProfiling(const char* title, bool record_samples) {
   if (profiles_->StartProfiling(title, next_profile_uid_++, record_samples)) {
     StartProcessorIfNotStarted();
   }
   processor_->AddCurrentStack(isolate_);
 }
 
 
 void CpuProfiler::StartProfiling(String* title, bool record_samples) {
   StartProfiling(profiles_->GetName(title), record_samples);
 }
 
 
 void CpuProfiler::StartProcessorIfNotStarted() {
   if (processor_ == NULL) {
     Logger* logger = isolate_->logger();
     // Disable logging when using the new implementation.
     saved_is_logging_ = logger->is_logging_;
     logger->is_logging_ = false;
     generator_ = new ProfileGenerator(profiles_);
     Sampler* sampler = logger->sampler();
     processor_ = new ProfilerEventsProcessor(
-        generator_, sampler,
-        TimeDelta::FromMicroseconds(FLAG_cpu_profiler_sampling_interval));
+        generator_, sampler, sampling_interval_);
     is_profiling_ = true;
     // Enumerate stuff we already have in the heap.
     ASSERT(isolate_->heap()->HasBeenSetUp());
     if (!FLAG_prof_browser_mode) {
       logger->LogCodeObjects();
     }
     logger->LogCompiledFunctions();
     logger->LogAccessorCallbacks();
     LogBuiltins();
     // Enable stack sampling.
@@ skipping 51 matching lines @@
     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 v8::internal