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Merged
aoikonomopoulos merged 1 commit into from
May 7, 2026
+26 −27
Merged

Eagerly unlinking CodeBlock when jettisoning https://bugs.webkit.org/… #1669

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46 changes: 23 additions & 23 deletions Source/JavaScriptCore/bytecode/CodeBlock.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2126,7 +2126,6 @@ CodeBlock* CodeBlock::newReplacement()
return ownerExecutable()->newReplacementCodeBlockFor(specializationKind());
}

#if ENABLE(JIT)
CodeBlock* CodeBlock::replacement()
{
const ClassInfo* classInfo = this->classInfo();
Expand All @@ -2147,6 +2146,7 @@ CodeBlock* CodeBlock::replacement()
return nullptr;
}

#if ENABLE(JIT)
DFG::CapabilityLevel CodeBlock::computeCapabilityLevel()
{
const ClassInfo* classInfo = this->classInfo();
Expand Down Expand Up @@ -2254,10 +2254,9 @@ void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mod
}
}
}

if (DFG::shouldDumpDisassembly())
dataLog(" Did invalidate ", *this, "\n");

// Count the reoptimization if that's what the user wanted.
if (mode == CountReoptimization) {
// FIXME: Maybe this should call alternative().
Expand All @@ -2266,32 +2265,33 @@ void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mod
if (DFG::shouldDumpDisassembly())
dataLog(" Did count reoptimization for ", *this, "\n");
}

if (this != replacement()) {
// This means that we were never the entrypoint. This can happen for OSR entry code
// blocks.
return;
}

if (alternative())
alternative()->optimizeAfterWarmUp();

if (reason != Profiler::JettisonDueToOldAge && reason != Profiler::JettisonDueToVMTraps)
tallyFrequentExitSites();
#endif // ENABLE(DFG_JIT)

// Jettison can happen during GC. We don't want to install code to a dead executable
// because that would add a dead object to the remembered set.
if (vm.heap.currentThreadIsDoingGCWork() && !vm.heap.isMarked(ownerExecutable()))
return;
// If this is not true, then this means that we were never the entrypoint. This can happen for OSR entry code blocks.
if (this == replacement()) {
#if ENABLE(DFG_JIT)
if (alternative())
alternative()->optimizeAfterWarmUp();

// This accomplishes (2).
ownerExecutable()->installCode(vm, alternative(), codeType(), specializationKind(), reason);
if (reason != Profiler::JettisonDueToOldAge && reason != Profiler::JettisonDueToVMTraps)
tallyFrequentExitSites();
#endif // ENABLE(DFG_JIT)

// Jettison can happen during GC. We don't want to install code to a dead executable
// because that would add a dead object to the remembered set.
if (!vm.heap.currentThreadIsDoingGCWork() || vm.heap.isMarked(ownerExecutable())) {
// This accomplishes (2).
ownerExecutable()->installCode(vm, alternative(), codeType(), specializationKind(), reason);
#if ENABLE(DFG_JIT)
if (DFG::shouldDumpDisassembly())
dataLog(" Did install baseline version of ", *this, "\n");
if (DFG::shouldDumpDisassembly())
dataLog(" Did install baseline version of ", *this, "\n");
#endif // ENABLE(DFG_JIT)
}
}

// Regardless of whether it is used or replaced or upgraded already or not, since this is already jettisoned,
// there is no reason to keep it linked. Unlink incoming calls.
unlinkIncomingCalls();
}

JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
Expand Down
7 changes: 3 additions & 4 deletions Source/JavaScriptCore/bytecode/CodeBlock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -319,8 +319,9 @@ class CodeBlock : public JSCell {

// Exactly equivalent to codeBlock->ownerExecutable()->newReplacementCodeBlockFor(codeBlock->specializationKind())
CodeBlock* newReplacement();

void setJITCode(Ref<JITCode>&& code)
CodeBlock* replacement();

void setJITCode(Ref<JSC::JITCode>&& code)
{
if (!code->isShared())
heap()->reportExtraMemoryAllocated(code->size());
Expand All @@ -347,8 +348,6 @@ class CodeBlock : public JSCell {
bool useDataIC() const;

#if ENABLE(JIT)
CodeBlock* replacement();

DFG::CapabilityLevel computeCapabilityLevel();
DFG::CapabilityLevel capabilityLevel();
DFG::CapabilityLevel capabilityLevelState() { return static_cast<DFG::CapabilityLevel>(m_capabilityLevelState); }
Expand Down