Cleanup extra initialization of TickSample fields.

R=vitalyr@chromium.org
BUG=1293

Review URL: http://codereview.chromium.org/7203005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8368 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/cpu-profiler-inl.h

@@ -32,6 +32,7 @@
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
+#include <new>
 #include "circular-queue-inl.h"
 #include "profile-generator-inl.h"
 #include "unbound-queue-inl.h"
@@ -62,24 +63,10 @@ void SharedFunctionInfoMoveEventRecord::UpdateCodeMap(CodeMap* code_map) {
 }
 
 
-TickSampleEventRecord* TickSampleEventRecord::init(void* value) {
-  TickSampleEventRecord* result =
-      reinterpret_cast<TickSampleEventRecord*>(value);
-  result->filler = 1;
-  ASSERT(result->filler != SamplingCircularQueue::kClear);
-  // Init the required fields only.
-  result->sample.pc = NULL;
-  result->sample.frames_count = 0;
-  result->sample.has_external_callback = false;
-  return result;
-}
-
-
 TickSample* ProfilerEventsProcessor::TickSampleEvent() {
   generator_->Tick();
   TickSampleEventRecord* evt =
-      TickSampleEventRecord::init(ticks_buffer_.Enqueue());
-  evt->order = enqueue_order_;  // No increment!
+      new(ticks_buffer_.Enqueue()) TickSampleEventRecord(enqueue_order_);
   return &evt->sample;
 }
 

src/cpu-profiler.cc

@@ -181,20 +181,16 @@ void ProfilerEventsProcessor::RegExpCodeCreateEvent(
 
 
 void ProfilerEventsProcessor::AddCurrentStack() {
-  TickSampleEventRecord record;
+  TickSampleEventRecord record(enqueue_order_);
   TickSample* sample = &record.sample;
   Isolate* isolate = Isolate::Current();
   sample->state = isolate->current_vm_state();
   sample->pc = reinterpret_cast<Address>(sample);  // Not NULL.
-  sample->tos = NULL;
-  sample->has_external_callback = false;
-  sample->frames_count = 0;
   for (StackTraceFrameIterator it(isolate);
        !it.done() && sample->frames_count < TickSample::kMaxFramesCount;
        it.Advance()) {
     sample->stack[sample->frames_count++] = it.frame()->pc();
   }
-  record.order = enqueue_order_;
   ticks_from_vm_buffer_.Enqueue(record);
 }
 

src/cpu-profiler.h

@@ -106,10 +106,14 @@ class SharedFunctionInfoMoveEventRecord : public CodeEventRecord {
 };
 
 
-class TickSampleEventRecord BASE_EMBEDDED {
+class TickSampleEventRecord {
  public:
-  TickSampleEventRecord()
-      : filler(1) {
+  // The parameterless constructor is used when we dequeue data from
+  // the ticks buffer.
+  TickSampleEventRecord() { }
+  explicit TickSampleEventRecord(unsigned order)
+      : filler(1),
+        order(order) {
     ASSERT(filler != SamplingCircularQueue::kClear);
   }
 
@@ -125,8 +129,6 @@ class TickSampleEventRecord BASE_EMBEDDED {
   static TickSampleEventRecord* cast(void* value) {
     return reinterpret_cast<TickSampleEventRecord*>(value);
   }
-
-  INLINE(static TickSampleEventRecord* init(void* value));
 };
 
 

src/log.cc

@@ -149,10 +149,6 @@ class Profiler: public Thread {
 void StackTracer::Trace(Isolate* isolate, TickSample* sample) {
   ASSERT(isolate->IsInitialized());
 
-  sample->tos = NULL;
-  sample->frames_count = 0;
-  sample->has_external_callback = false;
-
   // Avoid collecting traces while doing GC.
   if (sample->state == GC) return;