Initial GetSample implementation.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
 #include <cmath>  // For isnan.
 #include "include/v8-debug.h"
 #include "include/v8-profiler.h"
+#include "include/v8-sampler.h"
 #include "include/v8-testing.h"
 #include "src/assert-scope.h"
 #include "src/base/platform/platform.h"
 #include "src/base/platform/time.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/conversions-inl.h"
 #include "src/counters.h"
@@ skipping 7394 matching lines @@
   return reinterpret_cast<i::HeapProfiler*>(this)->
       GetMemorySizeUsedByProfiler();
 }
 
 
 void HeapProfiler::SetRetainedObjectInfo(UniqueId id,
                                          RetainedObjectInfo* info) {
   reinterpret_cast<i::HeapProfiler*>(this)->SetRetainedObjectInfo(id, info);
 }
 
+Sample* Sampler::GetSample(Isolate* isolate,
+                           Sample* sample) {
+  i::Isolate* isolate_ = reinterpret_cast<i::Isolate*>(isolate);
+
+  i::CpuProfiler* profiler_ = isolate_->cpu_profiler();
+  if (profiler_ == NULL) return NULL;
+
+  i::ProfilerEventsProcessor* processor_ = profiler_->processor();
+  if (processor_ == NULL) return NULL;
+
+  i::Sampler* sampler_ = processor_->sampler();
+  if (sampler_ == NULL) return NULL;

[fmeawad, 2014/07/29 18:30:50]

Can you cache those between calls?
i.e. check and store, start with sampler_ all the way back.

Also I think _ indicates private, with local variables do not use _ (double
check the coding guidelines).

[gholap, 2014/07/29 23:25:20]

Acknowledged.

+
+  return reinterpret_cast<Sample*>(
+    sampler_->GetSample(reinterpret_cast<i::TickSample*>(sample)));
+}
 
 v8::Testing::StressType internal::Testing::stress_type_ =
     v8::Testing::kStressTypeOpt;
 
 
 void Testing::SetStressRunType(Testing::StressType type) {
   internal::Testing::set_stress_type(type);
 }
 
 
@@ skipping 220 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal