darling-JavaScriptCore/heap/CollectorPhase.h
2018-01-02 21:17:19 -08:00

76 lines
3.1 KiB
C++

/*
* 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