Make number of available threads isolate-dependent and expose it to ResourceConstraints.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index dfb24783d016d6d2c5cde5106e93df6ce399cf5d..246cffd2c096fab687189833f493d61e41c5c0e5 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -465,7 +465,7 @@ void Heap::GarbageCollectionPrologue() {
 
   store_buffer()->GCPrologue();
 
-  if (FLAG_concurrent_osr) {
+  if (isolate()->concurrent_osr_enabled()) {
     isolate()->optimizing_compiler_thread()->AgeBufferedOsrJobs();
   }
 }
@@ -662,7 +662,7 @@ void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
   // Note: as weak callbacks can execute arbitrary code, we cannot
   // hope that eventually there will be no weak callbacks invocations.
   // Therefore stop recollecting after several attempts.
-  if (FLAG_concurrent_recompilation) {
+  if (isolate()->concurrent_recompilation_enabled()) {
     // The optimizing compiler may be unnecessarily holding on to memory.
     DisallowHeapAllocation no_recursive_gc;
     isolate()->optimizing_compiler_thread()->Flush();
@@ -763,7 +763,7 @@ bool Heap::CollectGarbage(AllocationSpace space,
 
 
 int Heap::NotifyContextDisposed() {
-  if (FLAG_concurrent_recompilation) {
+  if (isolate()->concurrent_recompilation_enabled()) {
     // Flush the queued recompilation tasks.
     isolate()->optimizing_compiler_thread()->Flush();
   }
@@ -6581,6 +6581,14 @@ intptr_t Heap::PromotedSpaceSizeOfObjects() {
 }
 
 
+bool Heap::AdvanceSweepers(int step_size) {
+  ASSERT(isolate()->num_sweeper_threads() == 0);
+  bool sweeping_complete = old_data_space()->AdvanceSweeper(step_size);
+  sweeping_complete &= old_pointer_space()->AdvanceSweeper(step_size);
+  return sweeping_complete;
+}
+
+
 intptr_t Heap::PromotedExternalMemorySize() {
   if (amount_of_external_allocated_memory_
       <= amount_of_external_allocated_memory_at_last_global_gc_) return 0;
@@ -6727,9 +6735,6 @@ bool Heap::SetUp() {
   store_buffer()->SetUp();
 
   if (FLAG_concurrent_recompilation) relocation_mutex_ = new Mutex;
-#ifdef DEBUG
-  relocation_mutex_locked_by_optimizer_thread_ = false;
-#endif  // DEBUG
 
   return true;
 }
@@ -6874,6 +6879,7 @@ void Heap::TearDown() {
   isolate_->memory_allocator()->TearDown();
 
   delete relocation_mutex_;
+  relocation_mutex_ = NULL;
 }
 
 
@@ -7953,15 +7959,4 @@ void Heap::CheckpointObjectStats() {
   ClearObjectStats();
 }
 
-
-Heap::RelocationLock::RelocationLock(Heap* heap) : heap_(heap) {
-  if (FLAG_concurrent_recompilation) {
-    heap_->relocation_mutex_->Lock();
-#ifdef DEBUG
-    heap_->relocation_mutex_locked_by_optimizer_thread_ =
-        heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
-#endif  // DEBUG
-  }
-}
-
 } }  // namespace v8::internal