Port base/watchdog to Linux.

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__
 
 #include <string>
 
 #include "base/condition_variable.h"
 #include "base/lock.h"
+#include "base/platform_thread.h"
 #include "base/time.h"
 
 class Watchdog {
  public:
-  // TODO(JAR)change default arg to required arg after all users have migrated.
   // Constructor specifies how long the Watchdog will wait before alarming.
   Watchdog(const base::TimeDelta& duration,
-           const std::wstring& thread_watched_name,
-           bool enabled = true);
+           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() {
     DLOG(INFO) << "Watchdog alarmed for " << thread_watched_name_;
   }
 
  private:
+  class ThreadDelegate : public PlatformThread::Delegate {
+   public:
+    explicit ThreadDelegate(Watchdog* watchdog, const base::TimeDelta& duration)

[wtc, 2008/11/25 23:00:13]

This constructor has two parameters, so it doesn't need to
be 'explicit'.

+      : watchdog_(watchdog), duration_(duration) {
+    }
+    virtual void ThreadMain();
+   private:
+    Watchdog* watchdog_;
+    const base::TimeDelta duration_;  // How long after start_time_ do we alarm?

[wtc, 2008/11/25 23:05:27]

Another comment: it's not clear to me why you moved
duration_ to the ThreadDelegate class.  It seems that
duration_ could stay in the Watchdog class, and ThreadDelegate
could access it as watchdog_->duration_.

+
+    void SetThreadName() const;
+  };
+
   enum State {ARMED, DISARMED, SHUTDOWN };
 
-  // Windows thread start callback
-  static DWORD WINAPI ThreadStart(void* pThis);
-
-  // Loop and test function for our watchdog thread.
-  unsigned Run();
-  void Watchdog::SetThreadName() const;
+  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::wstring thread_watched_name_;
-  HANDLE handle_;  // Handle for watchdog thread.
-  DWORD thread_id_;  // Also for watchdog thread.
+  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_EVIL_CONSTRUCTORS(Watchdog);
+  DISALLOW_COPY_AND_ASSIGN(Watchdog);
 };
 
 #endif  // BASE_WATCHDOG_H__