Add locker support to DebugMessageDispatchHandler

src/v8threads.h

 // Copyright 2008 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 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_V8THREADS_H_
 #define V8_V8THREADS_H_
 
 namespace v8 {
+
+struct LockParameters {
+  bool successfully_relaied;
+};
+
 namespace internal {
 
 
 class ThreadState {
  public:
   // Iterate over in-use states.
   static ThreadState* FirstInUse();
   // Returns NULL after the last one.
   ThreadState* Next();
 
@@ skipping 29 matching lines @@
 
   // In the following two lists there is always at least one object on the list.
   // The first object is a flying anchor that is only there to simplify linking
   // and unlinking.
   // Head of linked list of free states.
   static ThreadState* free_anchor_;
   // Head of linked list of states in use.
   static ThreadState* in_use_anchor_;
 };
 
+#ifdef ENABLE_DEBUGGER_SUPPORT
+
+struct Promises {
+  bool promise_to_process_debug_commands;
+  void Reset() {
+    promise_to_process_debug_commands = false;
+  }
+};
+
+// This mutex has an additional feature: you may try acquire it if it's free or
+// ASK someone who owns it right now to do a particular chore for you before
+// releasing it. The current owner is guaranteed to NOTICE your ask.
+class MutexWithResponsibilities {
+ public:
+  MutexWithResponsibilities();
+  ~MutexWithResponsibilities();
+  void Lock();
+  bool LockOrAsk(bool Promises::* promise);
+  void Unlock();
+
+ private:
+  Mutex* flag_mutex_;
+  Semaphore* sem_;
+  bool locked_;
+  bool has_promises_;
+  Promises promises_;
+};
+#endif
 
 class ThreadManager : public AllStatic {
  public:
   static void Lock();
   static void Unlock();
 
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  static bool LockOrAsk(bool Promises::* promise);
+#endif
   static void ArchiveThread();
   static bool RestoreThread();
   static void FreeThreadResources();
   static bool IsArchived();
 
   static void Iterate(ObjectVisitor* v);
   static void MarkCompactPrologue(bool is_compacting);
   static void MarkCompactEpilogue(bool is_compacting);
   static bool IsLockedByCurrentThread() { return mutex_owner_.IsSelf(); }
 
   static int CurrentId();
   static void AssignId();
   static bool HasId();
 
   static void TerminateExecution(int thread_id);
 
   static const int kInvalidId = -1;
  private:
   static void EagerlyArchiveThread();
 
   static int last_id_;  // V8 threads are identified through an integer.
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  static MutexWithResponsibilities* mutex_;
+#else
   static Mutex* mutex_;
+#endif
   static ThreadHandle mutex_owner_;
   static ThreadHandle lazily_archived_thread_;
   static ThreadState* lazily_archived_thread_state_;
 };
 
 
 // The ContextSwitcher thread is used to schedule regular preemptions to
 // multiple running V8 threads. Generally it is necessary to call
 // StartPreemption if there is more than one thread running. If not, a single
 // JavaScript can take full control of V8 and not allow other threads to run.
@@ skipping 16 matching lines @@
 
   bool keep_going_;
   int sleep_ms_;
 
   static ContextSwitcher* singleton_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8THREADS_H_