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Unified Diff: components/timers/rtc_alarm.h

Issue 706993003: C++ readability review (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Address comments Created 5 years, 8 months ago
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Index: components/timers/rtc_alarm.h
diff --git a/components/timers/rtc_alarm.h b/components/timers/rtc_alarm.h
deleted file mode 100644
index 8cc06bd49a570b612a6dc5b6de6527b409e3c4f3..0000000000000000000000000000000000000000
--- a/components/timers/rtc_alarm.h
+++ /dev/null
@@ -1,95 +0,0 @@
-// Copyright 2014 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.
-
-#ifndef COMPONENTS_TIMER_RTC_ALARM_H_
-#define COMPONENTS_TIMER_RTC_ALARM_H_
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/message_loop/message_loop.h"
-#include "base/time/time.h"
-#include "components/timers/alarm_timer.h"
-
-namespace base {
-class MessageLoopProxy;
-}
-
-namespace timers {
-// This class manages a Real Time Clock (RTC) alarm, a feature that is available
-// from linux version 3.11 onwards. It creates a file descriptor for the RTC
-// alarm timer and then watches that file descriptor to see when it can be read
-// without blocking, indicating that the timer has fired.
-//
-// A major problem for this class is that watching file descriptors is only
-// available on a MessageLoopForIO but there is no guarantee the timer is going
-// to be created on one. To get around this, the timer has a dedicated thread
-// with a MessageLoopForIO that posts tasks back to the thread that started the
-// timer.
-//
-// This class is designed to work together with the AlarmTimer class and is
-// tested through the AlarmTimer unit tests. DO NOT TRY TO USE THIS CLASS
-// DIRECTLY. Or use it anyway, I'm a comment not a cop.
-class RtcAlarm : public AlarmTimer::Delegate,
- public base::MessageLoopForIO::Watcher {
- public:
- RtcAlarm();
-
- // AlarmTimer::Delegate overrides.
- bool Init(base::WeakPtr<AlarmTimer> timer) override;
- void Stop() override;
- void Reset(base::TimeDelta delay) override;
-
- // base::MessageLoopForIO::Watcher overrides.
- void OnFileCanReadWithoutBlocking(int fd) override;
- void OnFileCanWriteWithoutBlocking(int fd) override;
-
- protected:
- // Needs to be protected because AlarmTimer::Delegate is a refcounted class.
- ~RtcAlarm() override;
-
- private:
- // Actually performs the system calls to set up the timer. This must be
- // called on a MessageLoopForIO.
- void ResetImpl(base::TimeDelta delay, int event_id);
-
- // Callback that is run when the timer fires. Must be run on
- // |origin_message_loop_|.
- void OnTimerFired(int event_id);
-
- // File descriptor associated with the alarm timer.
- int alarm_fd_;
-
- // Message loop which initially started the timer.
- scoped_refptr<base::MessageLoopProxy> origin_message_loop_;
-
- // The parent timer that should be informed when the timer fires. We may end
- // up outliving the parent so we need to ensure the reference is valid before
- // we try to call it.
- base::WeakPtr<AlarmTimer> parent_;
-
- // Manages watching file descriptors.
- scoped_ptr<base::MessageLoopForIO::FileDescriptorWatcher> fd_watcher_;
-
- // These two variables are used for coordinating between the thread that
- // started the timer and the IO thread being used to watch the timer file
- // descriptor. When Reset() is called, the original thread increments
- // |origin_event_id_| and binds its value to ResetImpl(), which gets posted to
- // the IO thread. When the IO thread runs, it saves this value in
- // |io_event_id_|. Later, when the timer fires, the IO thread binds the value
- // of |io_event_id_| to OnTimerFired() and posts it to the original thread.
- // When the original thread runs OnTimerFired(), it calls
- // parent_->OnTimerFired() only if |origin_event_id_| matches the event id
- // that was passed in to it. This is used to get around a race condition
- // where the user resets the timer on the original thread, while the event is
- // being fired on the IO thread at the same time.
- int origin_event_id_;
- int io_event_id_;
-
- DISALLOW_COPY_AND_ASSIGN(RtcAlarm);
-};
-
-} // namespace timers
-#endif // COMPONENTS_TIMER_RTC_ALARM_H_
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