third_party/WebKit/Source/core/frame/SuspendableTimer.cpp

/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "core/frame/SuspendableTimer.h"

#include "core/dom/TaskRunnerHelper.h"

namespace blink {

namespace {
// The lowest value returned by TimerBase::nextUnalignedFireInterval is 0.0
const double kNextFireIntervalInvalid = -1.0;
}

SuspendableTimer::SuspendableTimer(ExecutionContext* context, TaskType taskType)
    : TimerBase(TaskRunnerHelper::get(taskType, context)),
      ActiveDOMObject(context),
      m_nextFireInterval(kNextFireIntervalInvalid),
      m_repeatInterval(0)
#if ENABLE(ASSERT)
      ,
      m_suspended(false)
#endif
{
  DCHECK(context);
}

SuspendableTimer::~SuspendableTimer() {}

void SuspendableTimer::stop() {
  m_nextFireInterval = kNextFireIntervalInvalid;
  TimerBase::stop();
}

void SuspendableTimer::contextDestroyed() {
  stop();
}

void SuspendableTimer::suspend() {
#if ENABLE(ASSERT)
  ASSERT(!m_suspended);
  m_suspended = true;
#endif
  if (isActive()) {
    m_nextFireInterval = nextFireInterval();
    ASSERT(m_nextFireInterval >= 0.0);
    m_repeatInterval = repeatInterval();
    TimerBase::stop();
  }
}

void SuspendableTimer::resume() {
#if ENABLE(ASSERT)
  ASSERT(m_suspended);
  m_suspended = false;
#endif
  if (m_nextFireInterval >= 0.0) {
    // start() was called before, therefore location() is already set.
    // m_nextFireInterval is only set in suspend() if the Timer was active.
    start(m_nextFireInterval, m_repeatInterval, location());
    m_nextFireInterval = kNextFireIntervalInvalid;
  }
}

}  // namespace blink