sync/internal_api/public/base/cancelation_signal.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 "sync/internal_api/public/base/cancelation_signal.h"
   6
   7 #include "base/logging.h"
   8 #include "sync/internal_api/public/base/cancelation_observer.h"
   9
  10 namespace syncer {
  11
  12 CancelationSignal::CancelationSignal()
  13   : signalled_(false),
  14     handler_(NULL) { }
  15
  16 CancelationSignal::~CancelationSignal() {
  17   DCHECK(!handler_);
  18 }
  19
  20 bool CancelationSignal::TryRegisterHandler(CancelationObserver* handler) {
  21   base::AutoLock lock(signal_lock_);
  22   DCHECK(!handler_);
  23
  24   if (signalled_)
  25     return false;
  26
  27   handler_ = handler;
  28   return true;
  29 }
  30
  31 void CancelationSignal::UnregisterHandler(CancelationObserver* handler) {
  32   base::AutoLock lock(signal_lock_);
  33   DCHECK_EQ(handler_, handler);
  34   handler_ = NULL;
  35 }
  36
  37 bool CancelationSignal::IsSignalled() {
  38   base::AutoLock lock(signal_lock_);
  39   return signalled_;
  40 }
  41
  42 void CancelationSignal::Signal() {
  43   base::AutoLock lock(signal_lock_);
  44   DCHECK(!signalled_);
  45
  46   signalled_ = true;
  47   if (handler_) {
  48     handler_->OnSignalReceived();
  49   }
  50 }
  51
  52 }  // namespace syncer