| // Copyright 2013 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 NET_QUIC_QUIC_ALARM_H_ |
| #define NET_QUIC_QUIC_ALARM_H_ |
| |
| #include "base/memory/scoped_ptr.h" |
| #include "net/base/net_export.h" |
| #include "net/quic/quic_time.h" |
| |
| namespace net { |
| |
| // Abstract class which represents an alarm which will go off at a |
| // scheduled time, and execute the |OnAlarm| method of the delegate. |
| // An alarm may be cancelled, in which case it may or may not be |
| // removed from the underlying scheduling system, but in either case |
| // the task will not be executed. |
| class NET_EXPORT_PRIVATE QuicAlarm { |
| public: |
| class NET_EXPORT_PRIVATE Delegate { |
| public: |
| virtual ~Delegate() {} |
| |
| // Invoked when the alarm fires. If the return value is not |
| // infinite, then the alarm will be rescheduled at the |
| // specified time. |
| virtual QuicTime OnAlarm() = 0; |
| }; |
| |
| explicit QuicAlarm(Delegate* delegate); |
| virtual ~QuicAlarm(); |
| |
| // Sets the alarm to fire at |deadline|. Must not be called while |
| // the alarm is set. To reschedule an alarm, call Cancel() first, |
| // then Set(). |
| void Set(QuicTime deadline); |
| |
| // Cancels the alarm. May be called repeatedly. Does not |
| // guarantee that the underlying scheduling system will remove |
| // the alarm's associated task, but guarantees that the |
| // delegates OnAlarm method will not be called. |
| void Cancel(); |
| |
| bool IsSet() const; |
| |
| QuicTime deadline() const { return deadline_; } |
| |
| protected: |
| // Subclasses implement this method to perform the platform-specific |
| // scheduling of the alarm. Is called from Set() or Fire(), after the |
| // deadline has been updated. |
| virtual void SetImpl() = 0; |
| |
| // Subclasses implement this method to perform the platform-specific |
| // cancelation of the alarm. |
| virtual void CancelImpl() = 0; |
| |
| // Called by subclasses when the alarm fires. Invokes the |
| // delegates |OnAlarm| if a delegate is set, and if the deadline |
| // has been exceeded. Implementations which do not remove the |
| // alarm from the underlying scheduler on Cancel() may need to handle |
| // the situation where the task executes before the deadline has been |
| // reached, in which case they need to reschedule the task and must not |
| // call invoke this method. |
| void Fire(); |
| |
| private: |
| scoped_ptr<Delegate> delegate_; |
| QuicTime deadline_; |
| |
| DISALLOW_COPY_AND_ASSIGN(QuicAlarm); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_QUIC_ALARM_H_ |