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

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1681 matching lines @@
   IncrementalMarking* incremental_marking() {
     return &incremental_marking_;
   }
 
   bool IsSweepingComplete() {
     return !mark_compact_collector()->IsConcurrentSweepingInProgress() &&
            old_data_space()->IsLazySweepingComplete() &&
            old_pointer_space()->IsLazySweepingComplete();
   }
 
-  bool AdvanceSweepers(int step_size) {
-    ASSERT(!FLAG_parallel_sweeping && !FLAG_concurrent_sweeping);
-    bool sweeping_complete = old_data_space()->AdvanceSweeper(step_size);
-    sweeping_complete &= old_pointer_space()->AdvanceSweeper(step_size);
-    return sweeping_complete;
-  }
+  bool AdvanceSweepers(int step_size);
 
   bool EnsureSweepersProgressed(int step_size) {
     bool sweeping_complete = old_data_space()->EnsureSweeperProgress(step_size);
     sweeping_complete &= old_pointer_space()->EnsureSweeperProgress(step_size);
     return sweeping_complete;
   }
 
   ExternalStringTable* external_string_table() {
     return &external_string_table_;
   }
@@ skipping 108 matching lines @@
     object_counts_[FIRST_FIXED_ARRAY_SUB_TYPE + array_sub_type]++;
     object_sizes_[FIRST_FIXED_ARRAY_SUB_TYPE + array_sub_type] += size;
   }
 
   void CheckpointObjectStats();
 
   // We don't use a LockGuard here since we want to lock the heap
   // only when FLAG_concurrent_recompilation is true.
   class RelocationLock {
    public:
-    explicit RelocationLock(Heap* heap);
+    explicit RelocationLock(Heap* heap) : heap_(heap) {
+      if (FLAG_concurrent_recompilation) {
+        heap_->relocation_mutex_->Lock();
+      }
+    }
+
 
     ~RelocationLock() {
       if (FLAG_concurrent_recompilation) {
-#ifdef DEBUG
-        heap_->relocation_mutex_locked_by_optimizer_thread_ = false;
-#endif  // DEBUG
         heap_->relocation_mutex_->Unlock();
       }
     }
 
-#ifdef DEBUG
-    static bool IsLockedByOptimizerThread(Heap* heap) {
-      return heap->relocation_mutex_locked_by_optimizer_thread_;
-    }
-#endif  // DEBUG
-
    private:
     Heap* heap_;
   };
 
   MaybeObject* AddWeakObjectToCodeDependency(Object* obj, DependentCode* dep);
 
   DependentCode* LookupWeakObjectToCodeDependency(Object* obj);
 
   void InitializeWeakObjectToCodeTable() {
     set_weak_object_to_code_table(undefined_value());
@@ skipping 1227 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_