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/*
* Copyright (C) 2015-2022 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.
*/
#pragma once
#include "InternalFunctionAllocationProfile.h"
#include "JSCast.h"
#include "ObjectAllocationProfile.h"
#include "PackedCellPtr.h"
#include "Watchpoint.h"
namespace JSC {
class ExecutableBase;
class JSGlobalObject;
class LLIntOffsetsExtractor;
namespace DFG {
class SpeculativeJIT;
class JITCompiler;
}
class FunctionRareData final : public JSCell {
friend class JIT;
friend class DFG::SpeculativeJIT;
friend class DFG::JITCompiler;
friend class VM;
public:
typedef JSCell Base;
static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
static FunctionRareData* create(VM&, ExecutableBase*);
static constexpr DestructionMode needsDestruction = NeedsDestruction;
template<typename CellType, SubspaceAccess mode>
static GCClient::IsoSubspace* subspaceFor(VM& vm)
{
return vm.functionRareDataSpace<mode>();
}
static void destroy(JSCell*);
static Structure* createStructure(VM&, JSGlobalObject*, JSValue prototype);
DECLARE_VISIT_CHILDREN;
DECLARE_INFO;
static constexpr ptrdiff_t offsetOfObjectAllocationProfile() { return OBJECT_OFFSETOF(FunctionRareData, m_objectAllocationProfile); }
static constexpr ptrdiff_t offsetOfAllocationProfileWatchpointSet() { return OBJECT_OFFSETOF(FunctionRareData, m_allocationProfileWatchpointSet); }
static constexpr ptrdiff_t offsetOfInternalFunctionAllocationProfile() { return OBJECT_OFFSETOF(FunctionRareData, m_internalFunctionAllocationProfile); }
static constexpr ptrdiff_t offsetOfExecutable() { return OBJECT_OFFSETOF(FunctionRareData, m_executable); }
ObjectAllocationProfileWithPrototype* objectAllocationProfile()
{
return &m_objectAllocationProfile;
}
Structure* objectAllocationStructure() { return m_objectAllocationProfile.structure(); }
JSObject* objectAllocationPrototype() { return m_objectAllocationProfile.prototype(); }
InlineWatchpointSet& allocationProfileWatchpointSet()
{
return m_allocationProfileWatchpointSet;
}
void clear(const char* reason);
void initializeObjectAllocationProfile(VM&, JSGlobalObject*, JSObject* prototype, size_t inlineCapacity, JSFunction* constructor);
bool isObjectAllocationProfileInitialized() { return !m_objectAllocationProfile.isNull(); }
Structure* internalFunctionAllocationStructure() { return m_internalFunctionAllocationProfile.structure(); }
Structure* createInternalFunctionAllocationStructureFromBase(VM& vm, JSGlobalObject* baseGlobalObject, JSObject* prototype, Structure* baseStructure)
{
initializeAllocationProfileWatchpointSet();
return m_internalFunctionAllocationProfile.createAllocationStructureFromBase(vm, baseGlobalObject, this, prototype, baseStructure, allocationProfileWatchpointSet());
}
void clearInternalFunctionAllocationProfile(const char* reason)
{
m_internalFunctionAllocationProfile.clear();
m_allocationProfileWatchpointSet.fireAll(vm(), reason);
}
void initializeAllocationProfileWatchpointSet()
{
if (m_allocationProfileWatchpointSet.isStillValid())
m_allocationProfileWatchpointSet.startWatching();
}
Structure* getBoundFunctionStructure() { return m_boundFunctionStructureID.get(); }
void setBoundFunctionStructure(VM& vm, Structure* structure) { m_boundFunctionStructureID.set(vm, this, structure); }
ExecutableBase* executable() const { return m_executable.get(); }
bool hasReifiedLength() const { return m_hasReifiedLength; }
void setHasReifiedLength() { m_hasReifiedLength = true; }
bool hasReifiedName() const { return m_hasReifiedName; }
void setHasReifiedName() { m_hasReifiedName = true; }
bool hasModifiedLengthForBoundOrNonHostFunction() const { return m_hasModifiedLengthForBoundOrNonHostFunction; }
void setHasModifiedLengthForBoundOrNonHostFunction()
{
m_hasModifiedLengthForBoundOrNonHostFunction = true;
}
bool hasModifiedNameForBoundOrNonHostFunction() const { return m_hasModifiedNameForBoundOrNonHostFunction; }
void setHasModifiedNameForBoundOrNonHostFunction()
{
m_hasModifiedNameForBoundOrNonHostFunction = true;
}
bool hasAllocationProfileClearingWatchpoint() const { return !!m_allocationProfileClearingWatchpoint; }
Watchpoint* createAllocationProfileClearingWatchpoint();
class AllocationProfileClearingWatchpoint;
private:
friend class LLIntOffsetsExtractor;
explicit FunctionRareData(VM&, ExecutableBase*);
~FunctionRareData();
// Ideally, there would only be one allocation profile for subclassing but due to Reflect.construct we
// have two. There are some pros and cons in comparison to our current system to using the same profile
// for both JS constructors and subclasses of builtin constructors:
//
// 1) + Uses less memory.
// 2) + Conceptually simplier as there is only one profile.
// 3) - We would need a check in all JSFunction object creations (both with classes and without) that the
// new.target's profiled structure has a JSFinalObject ClassInfo. This is needed, for example, if we have
// `Reflect.construct(Array, args, myConstructor)` since myConstructor will be the new.target of Array
// the Array constructor will set the allocation profile of myConstructor to hold an Array structure
//
// We don't really care about 1) since this memory is rare and small in total. 2) is unfortunate but is
// probably outweighed by the cost of 3).
ObjectAllocationProfileWithPrototype m_objectAllocationProfile;
InlineWatchpointSet m_allocationProfileWatchpointSet;
InternalFunctionAllocationProfile m_internalFunctionAllocationProfile;
WriteBarrierStructureID m_boundFunctionStructureID;
WriteBarrier<ExecutableBase> m_executable;
std::unique_ptr<AllocationProfileClearingWatchpoint> m_allocationProfileClearingWatchpoint;
bool m_hasReifiedLength : 1;
bool m_hasReifiedName : 1;
bool m_hasModifiedLengthForBoundOrNonHostFunction : 1;
bool m_hasModifiedNameForBoundOrNonHostFunction : 1;
};
class FunctionRareData::AllocationProfileClearingWatchpoint final : public Watchpoint {
public:
AllocationProfileClearingWatchpoint(FunctionRareData* rareData)
: Watchpoint(Watchpoint::Type::FunctionRareDataAllocationProfileClearing)
, m_rareData(rareData)
{ }
void fireInternal(VM&, const FireDetail&);
private:
PackedCellPtr<FunctionRareData> m_rareData;
};
inline Watchpoint* FunctionRareData::createAllocationProfileClearingWatchpoint()
{
RELEASE_ASSERT(!hasAllocationProfileClearingWatchpoint());
m_allocationProfileClearingWatchpoint = makeUnique<AllocationProfileClearingWatchpoint>(this);
return m_allocationProfileClearingWatchpoint.get();
}
} // namespace JSC
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