/* * Copyright (C) 2017 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. AND ITS CONTRIBUTORS ``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 ITS 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 namespace JSC { // We track collector phase in order to allow either the collector thread or the mutator thread to // jump in and do work. The collector and mutator trade the conn // (https://en.wikipedia.org/wiki/Conn_(nautical)) with each other based on who is available to do work, // and they use the phase to help each other know what to do once they take the conn. // // The collector relinquishes the conn whenever it stopTheMutator's and the mutator is running. Then the // collector thread goes to sleep. // // The mutator relinquishes the conn whenever it releaseAccess's. That wakes up the collector thread. enum class CollectorPhase : uint8_t { // We use this phase when the collector is not running at all. After this state is Begin. NotRunning, // This is everything from when the collector begins to when it first yields to the mutator for // marking. After this is Fixpoint. Begin, // This means that we should try to do some progress with the world stopped. This usually means // doing an iteration of MarkingConstraintSet::executeConvergence, but it could also mean marking // with the world stopped. After this is either Concurrent or End. Fixpoint, // In this state the collector is relying on the parallel helpers and incremental mutator work to // make progress. After this is Reloop, once marking stalls. Concurrent, // We did some concurrent marking and now we ran out of work. This phase prepares the GC for another // Fixpoint. After this is Fixpoint. Reloop, // The collector is trying to finish up. After this state is NotRunning. End }; bool worldShouldBeSuspended(CollectorPhase phase); } // namespace JSC namespace WTF { class PrintStream; void printInternal(PrintStream&, JSC::CollectorPhase); } // namespace WTF