Watchdog - Added a JOINABLE state to avoid StartupTimebomb

base/threading/watchdog.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The Watchdog class creates a second thread that can Alarm if a specific
 // duration of time passes without proper attention.  The duration of time is
 // specified at construction time.  The Watchdog may be used many times by
 // simply calling Arm() (to start timing) and Disarm() (to reset the timer).
 // The Watchdog is typically used under a debugger, where the stack traces on
 // other threads can be examined if/when the Watchdog alarms.
 
@@ skipping 19 matching lines @@
 namespace base {
 
 class BASE_EXPORT Watchdog {
  public:
   // Constructor specifies how long the Watchdog will wait before alarming.
   Watchdog(const TimeDelta& duration,
            const std::string& thread_watched_name,
            bool enabled);
   virtual ~Watchdog();
 
+  // Notify watchdog thread to finish up. Sets the state_ to SHUTDOWN.
+  void Cleanup();
+
+  // Returns true if we state_ is JOINABLE (which indicates that Watchdog has
+  // exited).
+  bool IsJoinable();
+
   // Start timing, and alarm when time expires (unless we're disarm()ed.)
   void Arm();  // Arm  starting now.
   void ArmSomeTimeDeltaAgo(const TimeDelta& time_delta);
   void ArmAtStartTime(const TimeTicks start_time);
 
   // Reset time, and do not set off the alarm.
   void Disarm();
 
   // Alarm is called if the time expires after an Arm() without someone calling
   // Disarm().  This method can be overridden to create testable classes.
   virtual void Alarm();
 
   // Reset static data to initial state. Useful for tests, to ensure
   // they are independent.
   static void ResetStaticData();
 
  private:
   class ThreadDelegate : public PlatformThread::Delegate {
    public:
     explicit ThreadDelegate(Watchdog* watchdog) : watchdog_(watchdog) {
     }
     virtual void ThreadMain() OVERRIDE;
    private:
     void SetThreadName() const;
 
     Watchdog* watchdog_;
   };
 
-  enum State {ARMED, DISARMED, SHUTDOWN };
+  enum State {ARMED, DISARMED, SHUTDOWN, JOINABLE };
 
-  bool init_successful_;
+  bool enabled_;
 
   Lock lock_;  // Mutex for state_.
   ConditionVariable condition_variable_;
   State state_;
   const TimeDelta duration_;  // How long after start_time_ do we alarm?
   const std::string thread_watched_name_;
   PlatformThreadHandle handle_;
   ThreadDelegate delegate_;  // Store it, because it must outlive the thread.
 
   TimeTicks start_time_;  // Start of epoch, and alarm after duration_.
 
   DISALLOW_COPY_AND_ASSIGN(Watchdog);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_WATCHDOG_H_