/* * Copyright (C) 2017-2020 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 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. */ #pragma once #include "JSRunLoopTimer.h" #include "Strong.h" #include <wtf/Deque.h> #include <wtf/HashMap.h> #include <wtf/Lock.h> #include <wtf/Vector.h> namespace JSC { class JSPromise; class VM; class JSCell; class JS_EXPORT_PRIVATE DeferredWorkTimer final : public JSRunLoopTimer { public: using Base = JSRunLoopTimer; void doWork(VM&) final; using Ticket = JSObject*; void addPendingWork(VM&, Ticket, Vector<Strong<JSCell>>&& dependencies); bool hasPendingWork(Ticket); bool hasDependancyInPendingWork(Ticket, JSCell* dependency); bool cancelPendingWork(Ticket); // If the script execution owner your ticket is associated with gets canceled // the Task will not be called and will be deallocated. So it's important // to make sure your memory ownership model won't leak memory when // this occurs. The easiest way is to make sure everything is either owned // by a GC'd value in dependencies or by the Task lambda. using Task = Function<void()>; void scheduleWorkSoon(Ticket, Task&&); void didResumeScriptExecutionOwner(); void stopRunningTasks() { m_runTasks = false; } void runRunLoop(); static Ref<DeferredWorkTimer> create(VM& vm) { return adoptRef(*new DeferredWorkTimer(vm)); } private: DeferredWorkTimer(VM&); Lock m_taskLock; bool m_runTasks { true }; bool m_shouldStopRunLoopWhenAllTicketsFinish { false }; bool m_currentlyRunningTask { false }; Deque<std::tuple<Ticket, Task>> m_tasks; struct TicketData { Vector<Strong<JSCell>> dependencies; Strong<JSObject> scriptExecutionOwner; }; HashMap<Ticket, TicketData> m_pendingTickets; }; } // namespace JSC