Added system thread manager class.

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 269 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,
+    PARALLEL_MARKING
+  };
+
+  static int NumberOfParallelSystemThreads(ParallelSystemComponent type);
+
+  static const int kMaxThreads = 4;
+};
+
+
 #ifdef ENABLE_DEBUGGER_SUPPORT
 
 #define ISOLATE_DEBUGGER_INIT_LIST(V)                                          \
   V(v8::Debug::EventCallback, debug_event_callback, NULL)                      \
   V(DebuggerAgent*, debugger_agent_instance, NULL)
 #else
 
 #define ISOLATE_DEBUGGER_INIT_LIST(V)
 
 #endif
@@ skipping 1161 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_