Source/JavaScriptCore/bytecode/LLIntPrototypeLoadAdaptiveStructureWatchpoint.cpp

/*
 * Copyright (C) 2016-2019 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.
 */

#include "config.h"
#include "LLIntPrototypeLoadAdaptiveStructureWatchpoint.h"

#include "CodeBlock.h"
#include "Instruction.h"
#include "JSCInlines.h"

namespace JSC {

LLIntPrototypeLoadAdaptiveStructureWatchpoint::LLIntPrototypeLoadAdaptiveStructureWatchpoint(CodeBlock* owner, const ObjectPropertyCondition& key, unsigned bytecodeOffset)
    : Watchpoint(Watchpoint::Type::LLIntPrototypeLoadAdaptiveStructure)
    , m_owner(owner)
    , m_bytecodeOffset(bytecodeOffset)
    , m_key(key)
{
    RELEASE_ASSERT(key.watchingRequiresStructureTransitionWatchpoint());
    RELEASE_ASSERT(!key.watchingRequiresReplacementWatchpoint());
}

void LLIntPrototypeLoadAdaptiveStructureWatchpoint::install(VM& vm)
{
    RELEASE_ASSERT(m_key.isWatchable());

    m_key.object()->structure(vm)->addTransitionWatchpoint(this);
}

void LLIntPrototypeLoadAdaptiveStructureWatchpoint::fireInternal(VM& vm, const FireDetail&)
{
    if (!m_owner->isLive())
        return;

    if (m_key.isWatchable(PropertyCondition::EnsureWatchability)) {
        install(vm);
        return;
    }

    auto& instruction = m_owner->instructions().at(m_bytecodeOffset.get());
    clearLLIntGetByIdCache(instruction->as<OpGetById>().metadata(m_owner.get()));
}

void LLIntPrototypeLoadAdaptiveStructureWatchpoint::clearLLIntGetByIdCache(OpGetById::Metadata& metadata)
{
    // Keep hitCountForLLIntCaching value.
    metadata.m_modeMetadata.clearToDefaultModeWithoutCache();
}


} // namespace JSC