Collect samples for background threads.

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"
@@ skipping 256 matching lines @@
   }
 
   bool is_allocation_sample() const {
     return ClassAllocationSampleBit::decode(state_);
   }
 
   void set_is_allocation_sample(bool allocation_sample) {
     state_ = ClassAllocationSampleBit::update(allocation_sample, state_);
   }
 
+  bool is_mutator_thread() const {
+    return MutatorThreadBit::decode(state_);
+  }
+
+  void set_is_mutator_thread(bool mutator_thread) {
+    state_ = MutatorThreadBit::update(mutator_thread, state_);
+  }
+
   bool is_continuation_sample() const {
     return ContinuationSampleBit::decode(state_);
   }
 
   void SetContinuationIndex(intptr_t index) {
     ASSERT(!is_continuation_sample());
     ASSERT(continuation_index_ == -1);
     state_ = ContinuationSampleBit::update(true, state_);
     continuation_index_ = index;
     ASSERT(is_continuation_sample());
@@ skipping 44 matching lines @@
   static intptr_t pcs_length_;
   enum StateBits {
     kHeadSampleBit = 0,
     kLeafFrameIsDartBit = 1,
     kIgnoreBit = 2,
     kExitFrameBit = 3,
     kMissingFrameInsertedBit = 4,
     kTruncatedTraceBit = 5,
     kClassAllocationSampleBit = 6,
     kContinuationSampleBit = 7,
+    kMutatorThreadBit = 8,
   };
   class HeadSampleBit : public BitField<uword, bool, kHeadSampleBit, 1> {};
   class LeafFrameIsDart :
       public BitField<uword, bool, kLeafFrameIsDartBit, 1> {};
   class IgnoreBit : public BitField<uword, bool, kIgnoreBit, 1> {};
   class ExitFrameBit : public BitField<uword, bool, kExitFrameBit, 1> {};
   class MissingFrameInsertedBit
       : public BitField<uword, bool, kMissingFrameInsertedBit, 1> {};
   class TruncatedTraceBit :
       public BitField<uword, bool, kTruncatedTraceBit, 1> {};
   class ClassAllocationSampleBit
       : public BitField<uword, bool, kClassAllocationSampleBit, 1> {};
   class ContinuationSampleBit
       : public BitField<uword, bool, kContinuationSampleBit, 1> {};
+  class MutatorThreadBit
+      : public BitField<uword, bool, kMutatorThreadBit, 1> {};
 
   int64_t timestamp_;
   ThreadId tid_;
   Isolate* isolate_;
   uword pc_marker_;
   uword stack_buffer_[kStackBufferSizeInWords];
   uword vm_tag_;
   uword user_tag_;
   uword metadata_;
   uword lr_;
@@ skipping 268 matching lines @@
  private:
   ZoneGrowableArray<ProcessedSample*> samples_;
   CodeLookupTable* code_lookup_table_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessedSampleBuffer);
 };
 
 }  // namespace dart
 
 #endif  // VM_PROFILER_H_