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/*
* Copyright (C) 2015 Igalia S.L
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include <wtf/Atomics.h>
#include <wtf/Lock.h>
#include <wtf/MainThread.h>
#include <wtf/RunLoop.h>
#include <wtf/ThreadSafeRefCounted.h>
namespace WebCore {
template <typename T>
class MainThreadNotifier final : public ThreadSafeRefCounted<MainThreadNotifier<T>> {
public:
static Ref<MainThreadNotifier> create()
{
return adoptRef(*new MainThreadNotifier());
}
template<typename F>
void notify(T notificationType, const F& callbackFunctor)
{
ASSERT(m_isValid.load());
if (isMainThread()) {
removePendingNotification(notificationType);
callbackFunctor();
return;
}
if (!addPendingNotification(notificationType))
return;
RunLoop::main().dispatch([this, protectedThis = makeRef(*this), notificationType, callback = std::function<void()>(callbackFunctor)] {
if (!m_isValid.load())
return;
if (removePendingNotification(notificationType))
callback();
});
}
void cancelPendingNotifications(unsigned mask = 0)
{
ASSERT(m_isValid.load());
LockHolder locker(m_pendingNotificationsLock);
if (mask)
m_pendingNotifications &= ~mask;
else
m_pendingNotifications = 0;
}
void invalidate()
{
ASSERT(m_isValid.load());
m_isValid.store(false);
}
private:
MainThreadNotifier()
{
m_isValid.store(true);
}
bool addPendingNotification(T notificationType)
{
LockHolder locker(m_pendingNotificationsLock);
if (notificationType & m_pendingNotifications)
return false;
m_pendingNotifications |= notificationType;
return true;
}
bool removePendingNotification(T notificationType)
{
LockHolder locker(m_pendingNotificationsLock);
if (notificationType & m_pendingNotifications) {
m_pendingNotifications &= ~notificationType;
return true;
}
return false;
}
Lock m_pendingNotificationsLock;
unsigned m_pendingNotifications { 0 };
Atomic<bool> m_isValid;
};
} // namespace WebCore
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