Source/WebCore/bindings/js/DOMGCOutputConstraint.cpp

/*
 * Copyright (C) 2017-2018 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#include "config.h"
#include "DOMGCOutputConstraint.h"

#include "WebCoreJSClientData.h"
#include <JavaScriptCore/BlockDirectoryInlines.h>
#include <JavaScriptCore/HeapInlines.h>
#include <JavaScriptCore/HeapSnapshotBuilder.h>
#include <JavaScriptCore/MarkedBlockInlines.h>
#include <JavaScriptCore/SubspaceInlines.h>
#include <JavaScriptCore/VM.h>

namespace WebCore {

using namespace JSC;

DOMGCOutputConstraint::DOMGCOutputConstraint(VM& vm, JSVMClientData& clientData)
    : MarkingConstraint("Domo", "DOM Output", ConstraintVolatility::SeldomGreyed, ConstraintConcurrency::Concurrent, ConstraintParallelism::Parallel)
    , m_vm(vm)
    , m_clientData(clientData)
    , m_lastExecutionVersion(vm.heap.mutatorExecutionVersion())
{
}

DOMGCOutputConstraint::~DOMGCOutputConstraint()
{
}

void DOMGCOutputConstraint::executeImpl(SlotVisitor& visitor)
{
    Heap& heap = m_vm.heap;
    
    if (heap.mutatorExecutionVersion() == m_lastExecutionVersion)
        return;
    
    m_lastExecutionVersion = heap.mutatorExecutionVersion();
    
    m_clientData.forEachOutputConstraintSpace(
        [&] (Subspace& subspace) {
            auto func = [] (SlotVisitor& visitor, HeapCell* heapCell, HeapCell::Kind) {
                SetRootMarkReasonScope rootScope(visitor, SlotVisitor::RootMarkReason::DOMGCOutput);
                JSCell* cell = static_cast<JSCell*>(heapCell);
                cell->methodTable(visitor.vm())->visitOutputConstraints(cell, visitor);
            };
            
            visitor.addParallelConstraintTask(subspace.forEachMarkedCellInParallel(func));
        });
}
        
} // namespace WebCore