Source/JavaScriptCore/dfg/DFGAdaptiveInferredPropertyValueWatchpoint.cpp

/*
 * Copyright (C) 2015 Apple Inc. All rights reserved.
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#include "config.h"
#include "DFGAdaptiveInferredPropertyValueWatchpoint.h"

#if ENABLE(DFG_JIT)

#include "JSCInlines.h"

namespace JSC { namespace DFG {

AdaptiveInferredPropertyValueWatchpoint::AdaptiveInferredPropertyValueWatchpoint(
    const ObjectPropertyCondition& key,
    CodeBlock* codeBlock)
    : m_key(key)
    , m_codeBlock(codeBlock)
{
    RELEASE_ASSERT(key.kind() == PropertyCondition::Equivalence);
}

void AdaptiveInferredPropertyValueWatchpoint::install()
{
    RELEASE_ASSERT(m_key.isWatchable());
    
    m_key.object()->structure()->addTransitionWatchpoint(&m_structureWatchpoint);
    
    PropertyOffset offset = m_key.object()->structure()->getConcurrently(m_key.uid());
    WatchpointSet* set = m_key.object()->structure()->propertyReplacementWatchpointSet(offset);
    set->add(&m_propertyWatchpoint);
}

void AdaptiveInferredPropertyValueWatchpoint::fire(const FireDetail& detail)
{
    // One of the watchpoints fired, but the other one didn't. Make sure that neither of them are
    // in any set anymore. This simplifies things by allowing us to reinstall the watchpoints
    // wherever from scratch.
    if (m_structureWatchpoint.isOnList())
        m_structureWatchpoint.remove();
    if (m_propertyWatchpoint.isOnList())
        m_propertyWatchpoint.remove();
    
    if (m_key.isWatchable(PropertyCondition::EnsureWatchability)) {
        install();
        return;
    }
    
    if (DFG::shouldShowDisassembly()) {
        dataLog(
            "Firing watchpoint ", RawPointer(this), " (", m_key, ") on ", *m_codeBlock, "\n");
    }
    
    StringPrintStream out;
    out.print("Adaptation of ", m_key, " failed: ", detail);
    
    StringFireDetail stringDetail(out.toCString().data());
    
    m_codeBlock->jettison(
        Profiler::JettisonDueToUnprofiledWatchpoint, CountReoptimization, &stringDetail);
}

void AdaptiveInferredPropertyValueWatchpoint::StructureWatchpoint::fireInternal(
    const FireDetail& detail)
{
    ptrdiff_t myOffset = OBJECT_OFFSETOF(
        AdaptiveInferredPropertyValueWatchpoint, m_structureWatchpoint);
    
    AdaptiveInferredPropertyValueWatchpoint* parent =
        bitwise_cast<AdaptiveInferredPropertyValueWatchpoint*>(
            bitwise_cast<char*>(this) - myOffset);
    
    parent->fire(detail);
}

void AdaptiveInferredPropertyValueWatchpoint::PropertyWatchpoint::fireInternal(
    const FireDetail& detail)
{
    ptrdiff_t myOffset = OBJECT_OFFSETOF(
        AdaptiveInferredPropertyValueWatchpoint, m_propertyWatchpoint);
    
    AdaptiveInferredPropertyValueWatchpoint* parent =
        bitwise_cast<AdaptiveInferredPropertyValueWatchpoint*>(
            bitwise_cast<char*>(this) - myOffset);
    
    parent->fire(detail);
}

} } // namespace JSC::DFG

#endif // ENABLE(DFG_JIT)