Better handling of startup and shutdown of the debugger agent

src/debug-agent.h

 // Copyright 2006-2008 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 26 matching lines @@
 // Forward decelrations.
 class DebuggerAgentSession;
 
 
 // Debugger agent which starts a socket listener on the debugger port and
 // handles connection from a remote debugger.
 class DebuggerAgent: public Thread {
  public:
   explicit DebuggerAgent(int port)
       : port_(port), server_(OS::CreateSocket()), terminate_(false),
-        session_access_(OS::CreateMutex()), session_(NULL) {}
-  ~DebuggerAgent() {}
+        session_access_(OS::CreateMutex()), session_(NULL),
+        terminate_now_(OS::CreateSemaphore(0)) {}
+  ~DebuggerAgent() { delete server_; }
 
   void Shutdown();
 
  private:
   void Run();
   void CreateSession(Socket* socket);
   void DebuggerMessage(const uint16_t* message, int length);
-  void SessionClosed(DebuggerAgentSession* session);
+  void CloseSession();
+  void OnSessionClosed(DebuggerAgentSession* session);
 
   int port_;  // Port to use for the agent.
   Socket* server_;  // Server socket for listen/accept.
   bool terminate_;  // Termination flag.
   Mutex* session_access_;  // Mutex guarging access to session_.
   DebuggerAgentSession* session_;  // Current active session if any.
+  Semaphore* terminate_now_;  // Semaphore to signal termination.
 
   friend class DebuggerAgentSession;
   friend void DebuggerAgentMessageHandler(const uint16_t* message, int length,
                                           void *data);
 
   DISALLOW_COPY_AND_ASSIGN(DebuggerAgent);
 };
 
 
 // Debugger agent session. The session receives requests from the remote
 // debugger and sends debugger events/responses to the remote debugger.
 class DebuggerAgentSession: public Thread {
  public:
   DebuggerAgentSession(DebuggerAgent* agent, Socket* client)
       : agent_(agent), client_(client) {}
 
   void DebuggerMessage(Vector<uint16_t> message);
+  void Shutdown();
 
  private:
   void Run();
 
   void DebuggerMessage(Vector<char> message);
 
   DebuggerAgent* agent_;
-  const Socket* client_;
+  Socket* client_;
 
   DISALLOW_COPY_AND_ASSIGN(DebuggerAgentSession);
 };
 
 
 // Utility methods factored out to be used by the D8 shell as well.
 class DebuggerAgentUtil {
  public:
   static const char* kContentLength;
   static int kContentLengthSize;
 
   static SmartPointer<char> ReceiveMessage(const Socket* conn);
   static bool SendMessage(const Socket* conn, const Vector<uint16_t> message);
   static bool SendMessage(const Socket* conn,
                           const v8::Handle<v8::String> message);
   static int ReceiveAll(const Socket* conn, char* data, int len);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8_DEBUG_AGENT_H_