net/quic/quic_alarm.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/quic/quic_alarm.h"
   6
   7 #include "base/logging.h"
   8
   9 namespace net {
  10
  11 QuicAlarm::QuicAlarm(Delegate* delegate)
  12     : delegate_(delegate),
  13       deadline_(QuicTime::Zero()) {
  14 }
  15
  16 QuicAlarm::~QuicAlarm() {}
  17
  18 void QuicAlarm::Set(QuicTime deadline) {
  19   DCHECK(!IsSet());
  20   DCHECK(deadline.IsInitialized());
  21   deadline_ = deadline;
  22   SetImpl();
  23 }
  24
  25 void QuicAlarm::Cancel() {
  26   deadline_ = QuicTime::Zero();
  27   CancelImpl();
  28 }
  29
  30 void QuicAlarm::Update(QuicTime deadline, QuicTime::Delta granularity) {
  31   if (!deadline.IsInitialized()) {
  32     Cancel();
  33     return;
  34   }
  35   if (std::abs(deadline.Subtract(deadline_).ToMicroseconds()) <
  36           granularity.ToMicroseconds()) {
  37     return;
  38   }
  39   Cancel();
  40   Set(deadline);
  41 }
  42
  43 bool QuicAlarm::IsSet() const {
  44   return deadline_.IsInitialized();
  45 }
  46
  47 void QuicAlarm::Fire() {
  48   if (!deadline_.IsInitialized()) {
  49     return;
  50   }
  51
  52   deadline_ = QuicTime::Zero();
  53   QuicTime deadline = delegate_->OnAlarm();
  54   // delegate_->OnAlarm() might call Set(), in which case  deadline_ will
  55   // already contain the new value, so don't overwrite it.
  56   if (!deadline_.IsInitialized() && deadline.IsInitialized()) {
  57     Set(deadline);
  58   }
  59 }
  60
  61 }  // namespace net