darling-JavaScriptCore/heap/ConstraintVolatility.h
2017-08-12 09:48:01 -07:00

74 lines
2.7 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
#include <wtf/PrintStream.h>
namespace JSC {
enum class ConstraintVolatility : uint8_t {
// The constraint needs to be validated, but it is unlikely to ever produce information.
// It's best to run it at the bitter end.
SeldomGreyed,
// FIXME: We could introduce a new kind of volatility called GreyedByResumption, which
// would mean running all of the times that GreyedByExecution runs except as a root in a
// full GC.
// https://bugs.webkit.org/show_bug.cgi?id=166830
// The constraint needs to be reevaluated anytime the mutator runs: so at GC start and
// whenever the GC resuspends after a resumption. This is almost always something that
// you'd call a "root" in a traditional GC.
GreyedByExecution,
// The constraint needs to be reevaluated any time any object is marked and anytime the
// mutator resumes.
GreyedByMarking
};
} // namespace JSC
namespace WTF {
inline void printInternal(PrintStream& out, JSC::ConstraintVolatility volatility)
{
switch (volatility) {
case JSC::ConstraintVolatility::SeldomGreyed:
out.print("SeldomGreyed");
return;
case JSC::ConstraintVolatility::GreyedByExecution:
out.print("GreyedByExecuction");
return;
case JSC::ConstraintVolatility::GreyedByMarking:
out.print("GreyedByMarking");
return;
}
RELEASE_ASSERT_NOT_REACHED();
}
} // namespace WTF