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

src/isolate.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 283 matching lines @@
   // Whether out of memory exceptions should be ignored.
   bool ignore_out_of_memory_;
 
  private:
   void InitializeInternal();
 
   Address try_catch_handler_address_;
 };
 
 
-class SystemThreadManager {
- public:
-  enum ParallelSystemComponent {
-    PARALLEL_SWEEPING,
-    CONCURRENT_SWEEPING,
-    CONCURRENT_RECOMPILATION
-  };
-
-  static int NumberOfParallelSystemThreads(ParallelSystemComponent type);
-
-  static const int kMaxThreads = 4;
-};
-
-
 #ifdef ENABLE_DEBUGGER_SUPPORT
 
 #define ISOLATE_DEBUGGER_INIT_LIST(V)                                          \
   V(DebuggerAgent*, debugger_agent_instance, NULL)
 #else
 
 #define ISOLATE_DEBUGGER_INIT_LIST(V)
 
 #endif
 
@@ skipping 776 matching lines @@
       code_stub_interface_descriptor(int index);
 
   void IterateDeferredHandles(ObjectVisitor* visitor);
   void LinkDeferredHandles(DeferredHandles* deferred_handles);
   void UnlinkDeferredHandles(DeferredHandles* deferred_handles);
 
 #ifdef DEBUG
   bool IsDeferredHandle(Object** location);
 #endif  // DEBUG
 
+  void set_max_available_threads(int value) {
+    max_available_threads_ = value;
+  }
+
+  bool concurrent_recompilation_enabled() {
+    // Thread is only available with flag enabled.
+    ASSERT(optimizing_compiler_thread_ == NULL ||
+           FLAG_concurrent_recompilation);
+    return optimizing_compiler_thread_ != NULL;
+  }
+
+  bool concurrent_osr_enabled() {
+    // Thread is only available with flag enabled.
+    ASSERT(optimizing_compiler_thread_ == NULL ||
+           FLAG_concurrent_recompilation);
+    return optimizing_compiler_thread_ != NULL && FLAG_concurrent_osr;
+  }
+
   OptimizingCompilerThread* optimizing_compiler_thread() {
     return optimizing_compiler_thread_;
   }
 
+  bool num_sweeper_threads() {
+    return num_sweeper_threads_;
+  }
+
+  SweeperThread** sweeper_threads() {
+    return sweeper_thread_;
+  }
+
   // PreInits and returns a default isolate. Needed when a new thread tries
   // to create a Locker for the first time (the lock itself is in the isolate).
   // TODO(svenpanne) This method is on death row...
   static v8::Isolate* GetDefaultIsolateForLocking();
 
-  SweeperThread** sweeper_threads() {
-    return sweeper_thread_;
-  }
-
   int id() const { return static_cast<int>(id_); }
 
   HStatistics* GetHStatistics();
   HTracer* GetHTracer();
   CodeTracer* GetCodeTracer();
 
   FunctionEntryHook function_entry_hook() { return function_entry_hook_; }
   void set_function_entry_hook(FunctionEntryHook function_entry_hook) {
     function_entry_hook_ = function_entry_hook;
   }
@@ skipping 229 matching lines @@
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                              \
   static const intptr_t name##_debug_offset_;
   ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
   ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
   DeferredHandles* deferred_handles_head_;
   OptimizingCompilerThread* optimizing_compiler_thread_;
   SweeperThread** sweeper_thread_;
+  int num_sweeper_threads_;
+
+  // TODO(yangguo): This will become obsolete once ResourceConstraints
+  // becomes an argument to Isolate constructor.
+  int max_available_threads_;
 
   // Counts deopt points if deopt_every_n_times is enabled.
   unsigned int stress_deopt_count_;
 
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
   friend class IsolateInitializer;
   friend class OptimizingCompilerThread;
   friend class SweeperThread;
   friend class ThreadManager;
@@ skipping 188 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_