Add debug only counters to profiler

runtime/vm/profiler.h

 // 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.
 
 #ifndef VM_PROFILER_H_
 #define VM_PROFILER_H_
 
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
 #include "vm/code_observers.h"
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 #include "vm/object.h"
 #include "vm/tags.h"
 #include "vm/thread_interrupter.h"
 
 // Profiler sampling and stack walking support.
 // NOTE: For service related code, see profile_service.h.
 
 namespace dart {
 
 // Forward declarations.
 class ProcessedSample;
 class ProcessedSampleBuffer;
 
 class Sample;
 class SampleBuffer;
 class ProfileTrieNode;
 
+struct ProfilerCounters {
+  // Count of bail out reasons:
+  int64_t bail_out_unknown_task;
+  int64_t bail_out_jump_to_exception_handler;
+  int64_t bail_out_check_isolate;
+  // Count of single frame sampling reasons:
+  int64_t single_frame_sample_deoptimizing;
+  int64_t single_frame_sample_register_check;
+  int64_t single_frame_sample_get_and_validate_stack_bounds;
+  // Count of stack walkers used:
+  int64_t stack_walker_native;
+  int64_t stack_walker_dart_exit;
+  int64_t stack_walker_dart;
+  int64_t stack_walker_none;
+};
+
+
 class Profiler : public AllStatic {
  public:
   static void InitOnce();
   static void Shutdown();
 
   static void SetSampleDepth(intptr_t depth);
   static void SetSamplePeriod(intptr_t period);
 
   static SampleBuffer* sample_buffer() {
     return sample_buffer_;
   }
 
   static void DumpStackTrace(bool native_stack_trace = true);
 
   static void SampleAllocation(Thread* thread, intptr_t cid);
 
   // SampleThread is called from inside the signal handler and hence it is very
   // critical that the implementation of SampleThread does not do any of the
   // following:
   //   * Accessing TLS -- Because on Windows the callback will be running in a
   //                      different thread.
   //   * Allocating memory -- Because this takes locks which may already be
   //                          held, resulting in a dead lock.
   //   * Taking a lock -- See above.
   static void SampleThread(Thread* thread,
                            const InterruptedThreadState& state);
 
+  static ProfilerCounters counters() {
+    // Copies the counter values.
+    return counters_;
+  }
+
  private:
   // Does not walk the thread's stack.
   static void SampleThreadSingleFrame(Thread* thread, uintptr_t pc);
   static bool initialized_;
 
   static SampleBuffer* sample_buffer_;
 
+  static ProfilerCounters counters_;
+
   friend class Thread;
 };
 
 
 class SampleVisitor : public ValueObject {
  public:
   explicit SampleVisitor(Isolate* isolate) : isolate_(isolate), visited_(0) { }
   virtual ~SampleVisitor() {}
 
   virtual void VisitSample(Sample* sample) = 0;
@@ skipping 581 matching lines @@
  private:
   ZoneGrowableArray<ProcessedSample*> samples_;
   CodeLookupTable* code_lookup_table_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessedSampleBuffer);
 };
 
 }  // namespace dart
 
 #endif  // VM_PROFILER_H_