Move some misc thread-related stuff from base to base/thread and into the bas...

base/watchdog.h

-// Copyright (c) 2006-2008 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.
-
-// Some watchdogs will be enabled or disabled via command line switches. To
-// facilitate such code, an "enabled" argument for the constuctor can be used
-// to permanently disable the watchdog.  Disabled watchdogs don't even spawn
-// a second thread, and their methods call (Arm() and Disarm()) return very
-// quickly.
-
-#ifndef BASE_WATCHDOG_H__
-#define BASE_WATCHDOG_H__
-#pragma once
-
-#include <string>
-
-#include "base/condition_variable.h"
-#include "base/lock.h"
-#include "base/platform_thread.h"
-#include "base/time.h"
-
-class Watchdog {
- public:
-  // Constructor specifies how long the Watchdog will wait before alarming.
-  Watchdog(const base::TimeDelta& duration,
-           const std::string& thread_watched_name,
-           bool enabled);
-  virtual ~Watchdog();
-
-  // Start timing, and alarm when time expires (unless we're disarm()ed.)
-  void Arm();  // Arm  starting now.
-  void ArmSomeTimeDeltaAgo(const base::TimeDelta& time_delta);
-  void ArmAtStartTime(const base::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();
-   private:
-    Watchdog* watchdog_;
-
-    void SetThreadName() const;
-  };
-
-  enum State {ARMED, DISARMED, SHUTDOWN };
-
-  bool init_successful_;
-
-  Lock lock_;  // Mutex for state_.
-  ConditionVariable condition_variable_;
-  State state_;
-  const base::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.
-
-  base::TimeTicks start_time_;  // Start of epoch, and alarm after duration_.
-
-  // When the debugger breaks (when we alarm), all the other alarms that are
-  // armed will expire (also alarm).  To diminish this effect, we track any
-  // delay due to debugger breaks, and we *try* to adjust the effective start
-  // time of other alarms to step past the debugging break.
-  // Without this safety net, any alarm will typically trigger a host of follow
-  // on alarms from callers that specify old times.
-  static Lock static_lock_;  // Lock for access of static data...
-  // When did we last alarm and get stuck (for a while) in a debugger?
-  static base::TimeTicks last_debugged_alarm_time_;
-  // How long did we sit on a break in the debugger?
-  static base::TimeDelta last_debugged_alarm_delay_;
-
-  DISALLOW_COPY_AND_ASSIGN(Watchdog);
-};
-
-#endif  // BASE_WATCHDOG_H__