| /* |
| * 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 <functional> |
| #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, 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 = WTF::Function<void()>(WTFMove(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 |
| |