blob: 0aec10c3de6065ab10d5e9405313b325e53a34bb [file] [log] [blame]
/*
* Copyright (C) 2005-2019 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
// RefPtr is documented at http://webkit.org/coding/RefPtr.html
#pragma once
#include <algorithm>
#include <utility>
#include <wtf/FastMalloc.h>
#include <wtf/Ref.h>
namespace WTF {
template<typename T> struct DefaultRefDerefTraits {
static ALWAYS_INLINE void refIfNotNull(T* ptr)
{
if (LIKELY(ptr != nullptr))
ptr->ref();
}
static ALWAYS_INLINE void derefIfNotNull(T* ptr)
{
if (LIKELY(ptr != nullptr))
ptr->deref();
}
};
template<typename T, typename PtrTraits, typename RefDerefTraits> class RefPtr;
template<typename T, typename PtrTraits = RawPtrTraits<T>, typename RefDerefTraits = DefaultRefDerefTraits<T>> RefPtr<T, PtrTraits, RefDerefTraits> adoptRef(T*);
template<typename T, typename _PtrTraits, typename _RefDerefTraits>
class RefPtr {
WTF_MAKE_FAST_ALLOCATED;
public:
using PtrTraits = _PtrTraits;
using RefDerefTraits = _RefDerefTraits;
typedef T ValueType;
typedef ValueType* PtrType;
static constexpr bool isRefPtr = true;
ALWAYS_INLINE constexpr RefPtr() : m_ptr(nullptr) { }
ALWAYS_INLINE constexpr RefPtr(std::nullptr_t) : m_ptr(nullptr) { }
ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { RefDerefTraits::refIfNotNull(ptr); }
ALWAYS_INLINE RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { RefDerefTraits::refIfNotNull(PtrTraits::unwrap(m_ptr)); }
template<typename X, typename Y, typename Z> RefPtr(const RefPtr<X, Y, Z>& o) : m_ptr(o.get()) { RefDerefTraits::refIfNotNull(PtrTraits::unwrap(m_ptr)); }
ALWAYS_INLINE RefPtr(RefPtr&& o) : m_ptr(o.leakRef()) { }
template<typename X, typename Y, typename Z> RefPtr(RefPtr<X, Y, Z>&& o) : m_ptr(o.leakRef()) { }
template<typename X, typename Y> RefPtr(Ref<X, Y>&&);
// Hash table deleted values, which are only constructed and never copied or destroyed.
RefPtr(HashTableDeletedValueType) : m_ptr(PtrTraits::hashTableDeletedValue()) { }
bool isHashTableDeletedValue() const { return PtrTraits::isHashTableDeletedValue(m_ptr); }
ALWAYS_INLINE ~RefPtr() { RefDerefTraits::derefIfNotNull(PtrTraits::exchange(m_ptr, nullptr)); }
T* get() const { return PtrTraits::unwrap(m_ptr); }
Ref<T> releaseNonNull() { ASSERT(m_ptr); Ref<T> tmp(adoptRef(*m_ptr)); m_ptr = nullptr; return tmp; }
Ref<const T> releaseConstNonNull() { ASSERT(m_ptr); Ref<const T> tmp(adoptRef(*m_ptr)); m_ptr = nullptr; return tmp; }
T* leakRef() WARN_UNUSED_RETURN;
T& operator*() const { ASSERT(m_ptr); return *PtrTraits::unwrap(m_ptr); }
ALWAYS_INLINE T* operator->() const { return PtrTraits::unwrap(m_ptr); }
bool operator!() const { return !m_ptr; }
// This conversion operator allows implicit conversion to bool but not to other integer types.
using UnspecifiedBoolType = void (RefPtr::*)() const;
operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::unspecifiedBoolTypeInstance : nullptr; }
explicit operator bool() const { return !!m_ptr; }
RefPtr& operator=(const RefPtr&);
RefPtr& operator=(T*);
RefPtr& operator=(std::nullptr_t);
template<typename X, typename Y, typename Z> RefPtr& operator=(const RefPtr<X, Y, Z>&);
RefPtr& operator=(RefPtr&&);
template<typename X, typename Y, typename Z> RefPtr& operator=(RefPtr<X, Y, Z>&&);
template<typename X> RefPtr& operator=(Ref<X>&&);
template<typename X, typename Y, typename Z> void swap(RefPtr<X, Y, Z>&);
RefPtr copyRef() && = delete;
RefPtr copyRef() const & WARN_UNUSED_RETURN { return RefPtr(m_ptr); }
private:
void unspecifiedBoolTypeInstance() const { }
friend RefPtr adoptRef<T, PtrTraits, RefDerefTraits>(T*);
template<typename X, typename Y, typename Z> friend class RefPtr;
enum AdoptTag { Adopt };
RefPtr(T* ptr, AdoptTag) : m_ptr(ptr) { }
typename PtrTraits::StorageType m_ptr;
};
template<typename T, typename U, typename V>
template<typename X, typename Y>
inline RefPtr<T, U, V>::RefPtr(Ref<X, Y>&& reference)
: m_ptr(&reference.leakRef())
{
}
template<typename T, typename U, typename V>
inline T* RefPtr<T, U, V>::leakRef()
{
return U::exchange(m_ptr, nullptr);
}
template<typename T, typename U, typename V>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(const RefPtr& o)
{
RefPtr ptr = o;
swap(ptr);
return *this;
}
template<typename T, typename U, typename V>
template<typename X, typename Y, typename Z>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(const RefPtr<X, Y, Z>& o)
{
RefPtr ptr = o;
swap(ptr);
return *this;
}
template<typename T, typename U, typename V>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(T* optr)
{
RefPtr ptr = optr;
swap(ptr);
return *this;
}
template<typename T, typename U, typename V>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(std::nullptr_t)
{
V::derefIfNotNull(U::exchange(m_ptr, nullptr));
return *this;
}
template<typename T, typename U, typename V>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(RefPtr&& o)
{
RefPtr ptr = WTFMove(o);
swap(ptr);
return *this;
}
template<typename T, typename U, typename V>
template<typename X, typename Y, typename Z>
inline RefPtr<T, U, V>& RefPtr<T, U, V>::operator=(RefPtr<X, Y, Z>&& o)
{
RefPtr ptr = WTFMove(o);
swap(ptr);
return *this;
}
template<typename T, typename V, typename W>
template<typename U>
inline RefPtr<T, V, W>& RefPtr<T, V, W>::operator=(Ref<U>&& reference)
{
RefPtr ptr = WTFMove(reference);
swap(ptr);
return *this;
}
template<class T, typename U, typename V>
template<typename X, typename Y, typename Z>
inline void RefPtr<T, U, V>::swap(RefPtr<X, Y, Z>& o)
{
U::swap(m_ptr, o.m_ptr);
}
template<typename T, typename U, typename V>
inline void swap(RefPtr<T, U, V>& a, RefPtr<T, U, V>& b)
{
a.swap(b);
}
template<typename T, typename U, typename V, typename X, typename Y, typename Z>
inline bool operator==(const RefPtr<T, U, V>& a, const RefPtr<X, Y, Z>& b)
{
return a.get() == b.get();
}
template<typename T, typename U, typename V, typename X>
inline bool operator==(const RefPtr<T, U, V>& a, X* b)
{
return a.get() == b;
}
template<typename T, typename X, typename Y, typename Z>
inline bool operator==(T* a, const RefPtr<X, Y, Z>& b)
{
return a == b.get();
}
template<typename T, typename U, typename V, typename X, typename Y, typename Z>
inline bool operator!=(const RefPtr<T, U, V>& a, const RefPtr<X, Y, Z>& b)
{
return a.get() != b.get();
}
template<typename T, typename U, typename V, typename X>
inline bool operator!=(const RefPtr<T, U, V>& a, X* b)
{
return a.get() != b;
}
template<typename T, typename X, typename Y, typename Z>
inline bool operator!=(T* a, const RefPtr<X, Y, Z>& b)
{
return a != b.get();
}
template<typename T, typename U = RawPtrTraits<T>, typename V = DefaultRefDerefTraits<T>, typename X, typename Y, typename Z>
inline RefPtr<T, U, V> static_pointer_cast(const RefPtr<X, Y, Z>& p)
{
return RefPtr<T, U, V>(static_cast<T*>(p.get()));
}
template <typename T, typename U, typename V>
struct IsSmartPtr<RefPtr<T, U, V>> {
static constexpr bool value = true;
};
template<typename T, typename U, typename V>
inline RefPtr<T, U, V> adoptRef(T* p)
{
adopted(p);
return RefPtr<T, U, V>(p, RefPtr<T, U, V>::Adopt);
}
template<typename ExpectedType, typename ArgType, typename PtrTraits, typename RefDerefTraits>
inline bool is(RefPtr<ArgType, PtrTraits, RefDerefTraits>& source)
{
return is<ExpectedType>(source.get());
}
template<typename ExpectedType, typename ArgType, typename PtrTraits, typename RefDerefTraits>
inline bool is(const RefPtr<ArgType, PtrTraits, RefDerefTraits>& source)
{
return is<ExpectedType>(source.get());
}
} // namespace WTF
using WTF::RefPtr;
using WTF::adoptRef;
using WTF::static_pointer_cast;