#pragma once
#include <wtf/Assertions.h>
#include "Handle.h"
#include "HandleSet.h"
#include "JSLock.h"
namespace JSC {
class VM;
template <typename T, ShouldStrongDestructorGrabLock shouldStrongDestructorGrabLock = ShouldStrongDestructorGrabLock::No> class Strong : public Handle<T> {
using Handle<T>::slot;
using Handle<T>::setSlot;
template <typename U, ShouldStrongDestructorGrabLock> friend class Strong;
public:
typedef typename Handle<T>::ExternalType ExternalType;
Strong()
: Handle<T>()
{
}
Strong(VM&, ExternalType = ExternalType());
Strong(VM&, Handle<T>);
Strong(const Strong& other)
: Handle<T>()
{
if (!other.slot())
return;
setSlot(HandleSet::heapFor(other.slot())->allocate());
set(other.get());
}
template <typename U> Strong(const Strong<U>& other)
: Handle<T>()
{
if (!other.slot())
return;
setSlot(HandleSet::heapFor(other.slot())->allocate());
set(other.get());
}
enum HashTableDeletedValueTag { HashTableDeletedValue };
bool isHashTableDeletedValue() const { return slot() == hashTableDeletedValue(); }
Strong(HashTableDeletedValueTag)
: Handle<T>(hashTableDeletedValue())
{
}
~Strong()
{
clear();
}
bool operator!() const { return !slot() || !*slot(); }
explicit operator bool() const { return !!*this; }
void swap(Strong& other)
{
Handle<T>::swap(other);
}
ExternalType get() const { return HandleTypes<T>::getFromSlot(this->slot()); }
void set(VM&, ExternalType);
template <typename U> Strong& operator=(const Strong<U>& other)
{
if (!other.slot()) {
clear();
return *this;
}
set(*HandleSet::heapFor(other.slot())->vm(), other.get());
return *this;
}
Strong& operator=(const Strong& other)
{
if (!other.slot()) {
clear();
return *this;
}
set(HandleSet::heapFor(other.slot())->vm(), other.get());
return *this;
}
void clear()
{
if (!slot())
return;
auto* heap = HandleSet::heapFor(slot());
if (shouldStrongDestructorGrabLock == ShouldStrongDestructorGrabLock::Yes) {
JSLockHolder holder(heap->vm());
heap->deallocate(slot());
setSlot(nullptr);
} else {
heap->deallocate(slot());
setSlot(nullptr);
}
}
private:
static HandleSlot hashTableDeletedValue() { return reinterpret_cast<HandleSlot>(-1); }
void set(ExternalType externalType)
{
ASSERT(slot());
JSValue value = HandleTypes<T>::toJSValue(externalType);
HandleSet::heapFor(slot())->writeBarrier(slot(), value);
*slot() = value;
}
};
template<class T> inline void swap(Strong<T>& a, Strong<T>& b)
{
a.swap(b);
}
}
namespace WTF {
template<typename T> struct VectorTraits<JSC::Strong<T>> : SimpleClassVectorTraits {
static constexpr bool canCompareWithMemcmp = false;
};
template<typename P> struct HashTraits<JSC::Strong<P>> : SimpleClassHashTraits<JSC::Strong<P>> { };
}