Collect samples during isolate startup

runtime/vm/profiler.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
 #include "vm/code_patcher.h"
 #include "vm/isolate.h"
@@ skipping 12 matching lines @@
 #if defined(USING_SIMULATOR) || defined(TARGET_OS_WINDOWS) || \
     defined(TARGET_OS_ANDROID)
   DEFINE_FLAG(bool, profile, false, "Enable Sampling Profiler");
 #else
   DEFINE_FLAG(bool, profile, true, "Enable Sampling Profiler");
 #endif
 DEFINE_FLAG(bool, trace_profiled_isolates, false, "Trace profiled isolates.");
 DEFINE_FLAG(charp, profile_dir, NULL,
             "Enable writing profile data into specified directory.");
 DEFINE_FLAG(int, profile_period, 1000,
-            "Time between profiler samples in microseconds. Minimum 250.");
+            "Time between profiler samples in microseconds. Minimum 50.");
 DEFINE_FLAG(int, profile_depth, 8,
             "Maximum number stack frames walked. Minimum 1. Maximum 255.");
 DEFINE_FLAG(bool, profile_verify_stack_walk, false,
             "Verify instruction addresses while walking the stack.");
 DEFINE_FLAG(bool, profile_native_stack, true,
             "Use native stack in profiler.");
 
 bool Profiler::initialized_ = false;
 SampleBuffer* Profiler::sample_buffer_ = NULL;
 
@@ skipping 30 matching lines @@
     FLAG_profile_depth = kMinimumDepth;
   } else if (depth > kMaximumDepth) {
     FLAG_profile_depth = kMaximumDepth;
   } else {
     FLAG_profile_depth = depth;
   }
 }
 
 
 void Profiler::SetSamplePeriod(intptr_t period) {
-  const int kMinimumProfilePeriod = 250;
+  const int kMinimumProfilePeriod = 50;
   if (period < kMinimumProfilePeriod) {
     FLAG_profile_period = kMinimumProfilePeriod;
   } else {
     FLAG_profile_period = period;
   }
 }
 
 
 void Profiler::InitProfilingForIsolate(Isolate* isolate, bool shared_buffer) {
   if (!FLAG_profile) {
     return;
   }
+  ASSERT(isolate == Isolate::Current());
   ASSERT(isolate != NULL);
   ASSERT(sample_buffer_ != NULL);
   {
     MutexLocker profiler_data_lock(isolate->profiler_data_mutex());
     SampleBuffer* sample_buffer = sample_buffer_;
     if (!shared_buffer) {
       sample_buffer = new SampleBuffer();
     }
     IsolateProfilerData* profiler_data =
         new IsolateProfilerData(sample_buffer, !shared_buffer);
     ASSERT(profiler_data != NULL);
     isolate->set_profiler_data(profiler_data);
     if (FLAG_trace_profiled_isolates) {
       OS::Print("Profiler Setup %p %s\n", isolate, isolate->name());
     }
   }
+  BeginExecution(isolate);
 }
 
 
 void Profiler::ShutdownProfilingForIsolate(Isolate* isolate) {
   ASSERT(isolate != NULL);
   if (!FLAG_profile) {
     return;
   }
   // We do not have a current isolate.
   ASSERT(Isolate::Current() == NULL);
@@ skipping 1558 matching lines @@
 
 
 void Profiler::RecordSampleInterruptCallback(
     const InterruptedThreadState& state,
     void* data) {
   Isolate* isolate = reinterpret_cast<Isolate*>(data);
   if ((isolate == NULL) || (Dart::vm_isolate() == NULL)) {
     return;
   }
   ASSERT(isolate != Dart::vm_isolate());
-  ASSERT(isolate->stub_code() != NULL);
   VMTagCounters* counters = isolate->vm_tag_counters();
   ASSERT(counters != NULL);
   counters->Increment(isolate->vm_tag());
   IsolateProfilerData* profiler_data = isolate->profiler_data();
   if (profiler_data == NULL) {
     return;
   }
   SampleBuffer* sample_buffer = profiler_data->sample_buffer();
   if (sample_buffer == NULL) {
     return;
   }
   Sample* sample = sample_buffer->ReserveSample();
   sample->Init(isolate, OS::GetCurrentTimeMicros(), state.tid);
   sample->set_vm_tag(isolate->vm_tag());
   sample->set_user_tag(isolate->user_tag());
   if (FLAG_profile_native_stack) {
     // Collect native and Dart frames.
     uword stack_lower = 0;
     uword stack_upper = 0;
     isolate->GetStackBounds(&stack_lower, &stack_upper);
     if ((stack_lower == 0) || (stack_upper == 0)) {
       stack_lower = 0;
       stack_upper = 0;
     }
     ProfilerNativeStackWalker stackWalker(sample, stack_lower, stack_upper,
                                           state.pc, state.fp, state.sp);
     stackWalker.walk(isolate->heap());
   } else {
-    if (isolate->top_exit_frame_info() != 0) {
+    if ((isolate->top_exit_frame_info() != 0) &&
+        (isolate->stub_code() != NULL)) {
       ProfilerDartStackWalker stackWalker(sample);
       stackWalker.walk();
     } else {
       // TODO(johnmccutchan): Support collecting only Dart frames with
       // ProfilerNativeStackWalker.
     }
   }
 }
 
 }  // namespace dart