Source/JavaScriptCore/bytecode/AdaptiveInferredPropertyValueWatchpointBase.cpp

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#include "config.h"
#include "AdaptiveInferredPropertyValueWatchpointBase.h"

#include "JSCellInlines.h"
#include "StructureInlines.h"

namespace JSC {

AdaptiveInferredPropertyValueWatchpointBase::AdaptiveInferredPropertyValueWatchpointBase(const ObjectPropertyCondition& key)
    : m_key(key)
{
    RELEASE_ASSERT(key.kind() == PropertyCondition::Equivalence);
}

void AdaptiveInferredPropertyValueWatchpointBase::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 AdaptiveInferredPropertyValueWatchpointBase::fire(const FireDetail& detail)
{
    // We need to defer GC here otherwise we might trigger a GC that could destroy the owner
    // CodeBlock. In particular, this can happen when we add rare data to a structure when
    // we EnsureWatchability.
    DeferGCForAWhile defer(*Heap::heap(m_key.object()));
    // 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;
    }

    handleFire(detail);
}

void AdaptiveInferredPropertyValueWatchpointBase::StructureWatchpoint::fireInternal(const FireDetail& detail)
{
    ptrdiff_t myOffset = OBJECT_OFFSETOF(AdaptiveInferredPropertyValueWatchpointBase, m_structureWatchpoint);

    AdaptiveInferredPropertyValueWatchpointBase* parent = bitwise_cast<AdaptiveInferredPropertyValueWatchpointBase*>(bitwise_cast<char*>(this) - myOffset);

    parent->fire(detail);
}

void AdaptiveInferredPropertyValueWatchpointBase::PropertyWatchpoint::fireInternal(const FireDetail& detail)
{
    ptrdiff_t myOffset = OBJECT_OFFSETOF(AdaptiveInferredPropertyValueWatchpointBase, m_propertyWatchpoint);

    AdaptiveInferredPropertyValueWatchpointBase* parent = bitwise_cast<AdaptiveInferredPropertyValueWatchpointBase*>(bitwise_cast<char*>(this) - myOffset);
    
    parent->fire(detail);
}
    
} // namespace JSC