Implement safepointing of threads

runtime/vm/heap.h

 // Copyright (c) 2012, 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_HEAP_H_
 #define VM_HEAP_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/flags.h"
@@ skipping 305 matching lines @@
       Thread* thread, ApiCallbacks api_callbacks, GCReason reason);
 
   // GC stats collection.
   void RecordBeforeGC(Space space, GCReason reason);
   void RecordAfterGC(Space space);
   void PrintStats();
   void UpdateClassHeapStatsBeforeGC(Heap::Space space);
   void UpdatePretenurePolicy();
 
   // Updates gc in progress flags.
-  bool BeginNewSpaceGC();
+  bool BeginNewSpaceGC(Thread* thread);
   void EndNewSpaceGC();
-  bool BeginOldSpaceGC();
+  bool BeginOldSpaceGC(Thread* thread);
   void EndOldSpaceGC();
 
   // If this heap is non-empty, updates start and end to the smallest range that
   // contains both the original [start, end) and the [lowest, highest) addresses
   // of this heap.
   void GetMergedAddressRange(uword* start, uword* end) const;
 
   Isolate* isolate_;
 
   // The different spaces used for allocation.
@@ skipping 50 matching lines @@
   explicit WritableVMIsolateScope(Thread* thread, bool include_code_pages);
   ~WritableVMIsolateScope();
 
  private:
   bool include_code_pages_;
 };
 
 }  // namespace dart
 
 #endif  // VM_HEAP_H_