/*
* Copyright (C) 2005 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_STRONG_POINTER_H
#define ANDROID_STRONG_POINTER_H
// ---------------------------------------------------------------------------
namespace android {
template<typename T> class wp;
// ---------------------------------------------------------------------------
#define COMPARE(_op_) \
inline bool operator _op_ (const sp<T>& o) const { \
return m_ptr _op_ o.m_ptr; \
} \
inline bool operator _op_ (const T* o) const { \
return m_ptr _op_ o; \
} \
template<typename U> \
inline bool operator _op_ (const sp<U>& o) const { \
return m_ptr _op_ o.m_ptr; \
} \
template<typename U> \
inline bool operator _op_ (const U* o) const { \
return m_ptr _op_ o; \
} \
inline bool operator _op_ (const wp<T>& o) const { \
return m_ptr _op_ o.m_ptr; \
} \
template<typename U> \
inline bool operator _op_ (const wp<U>& o) const { \
return m_ptr _op_ o.m_ptr; \
}
// ---------------------------------------------------------------------------
template<typename T>
class sp {
public:
inline sp() : m_ptr(0) { }
sp(T* other); // NOLINT(implicit)
sp(const sp<T>& other);
sp(sp<T>&& other);
template<typename U> sp(U* other); // NOLINT(implicit)
template<typename U> sp(const sp<U>& other); // NOLINT(implicit)
template<typename U> sp(sp<U>&& other); // NOLINT(implicit)
~sp();
// Assignment
sp& operator = (T* other);
sp& operator = (const sp<T>& other);
sp& operator = (sp<T>&& other);
template<typename U> sp& operator = (const sp<U>& other);
template<typename U> sp& operator = (sp<U>&& other);
template<typename U> sp& operator = (U* other);
//! Special optimization for use by ProcessState (and nobody else).
void force_set(T* other);
// Reset
void clear();
// Accessors
inline T& operator* () const { return *m_ptr; }
inline T* operator-> () const { return m_ptr; }
inline T* get() const { return m_ptr; }
// Operators
COMPARE(==)
COMPARE(!=)
COMPARE(>)
COMPARE(<)
COMPARE(<=)
COMPARE(>=)
private:
template<typename Y> friend class sp;
template<typename Y> friend class wp;
void set_pointer(T* ptr);
T* m_ptr;
};
// For code size reasons, we do not want this inlined or templated.
void sp_report_race();
#undef COMPARE
// ---------------------------------------------------------------------------
// No user serviceable parts below here.
template<typename T>
sp<T>::sp(T* other)
: m_ptr(other) {
if (other)
other->incStrong(this);
}
template<typename T>
sp<T>::sp(const sp<T>& other)
: m_ptr(other.m_ptr) {
if (m_ptr)
m_ptr->incStrong(this);
}
template<typename T>
sp<T>::sp(sp<T>&& other)
: m_ptr(other.m_ptr) {
other.m_ptr = nullptr;
}
template<typename T> template<typename U>
sp<T>::sp(U* other)
: m_ptr(other) {
if (other)
(static_cast<T*>(other))->incStrong(this);
}
template<typename T> template<typename U>
sp<T>::sp(const sp<U>& other)
: m_ptr(other.m_ptr) {
if (m_ptr)
m_ptr->incStrong(this);
}
template<typename T> template<typename U>
sp<T>::sp(sp<U>&& other)
: m_ptr(other.m_ptr) {
other.m_ptr = nullptr;
}
template<typename T>
sp<T>::~sp() {
if (m_ptr)
m_ptr->decStrong(this);
}
template<typename T>
sp<T>& sp<T>::operator =(const sp<T>& other) {
// Force m_ptr to be read twice, to heuristically check for data races.
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
T* otherPtr(other.m_ptr);
if (otherPtr) otherPtr->incStrong(this);
if (oldPtr) oldPtr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = otherPtr;
return *this;
}
template<typename T>
sp<T>& sp<T>::operator =(sp<T>&& other) {
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
if (oldPtr) oldPtr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = other.m_ptr;
other.m_ptr = nullptr;
return *this;
}
template<typename T>
sp<T>& sp<T>::operator =(T* other) {
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
if (other) other->incStrong(this);
if (oldPtr) oldPtr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = other;
return *this;
}
template<typename T> template<typename U>
sp<T>& sp<T>::operator =(const sp<U>& other) {
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
T* otherPtr(other.m_ptr);
if (otherPtr) otherPtr->incStrong(this);
if (oldPtr) oldPtr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = otherPtr;
return *this;
}
template<typename T> template<typename U>
sp<T>& sp<T>::operator =(sp<U>&& other) {
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
if (m_ptr) m_ptr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = other.m_ptr;
other.m_ptr = nullptr;
return *this;
}
template<typename T> template<typename U>
sp<T>& sp<T>::operator =(U* other) {
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
if (other) (static_cast<T*>(other))->incStrong(this);
if (oldPtr) oldPtr->decStrong(this);
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
m_ptr = other;
return *this;
}
template<typename T>
void sp<T>::force_set(T* other) {
other->forceIncStrong(this);
m_ptr = other;
}
template<typename T>
void sp<T>::clear() {
if (m_ptr) {
m_ptr->decStrong(this);
m_ptr = 0;
}
}
template<typename T>
void sp<T>::set_pointer(T* ptr) {
m_ptr = ptr;
}
}; // namespace android
// ---------------------------------------------------------------------------
#endif // ANDROID_STRONG_POINTER_H