274 lines
8.5 KiB
C++
274 lines
8.5 KiB
C++
/*
|
|
* 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 AML_MP_STRONG_POINTER_H
|
|
#define AML_MP_STRONG_POINTER_H
|
|
|
|
#include <functional>
|
|
#include <type_traits> // for common_type.
|
|
|
|
// ---------------------------------------------------------------------------
|
|
namespace aml_mp {
|
|
|
|
template<typename T> class wptr;
|
|
|
|
// ---------------------------------------------------------------------------
|
|
|
|
// TODO: Maybe remove sp<> ? wp<> comparison? These are dangerous: If the wp<>
|
|
// was created before the sp<>, and they point to different objects, they may
|
|
// compare equal even if they are entirely unrelated. E.g. CameraService
|
|
// currently perform such comparisons.
|
|
|
|
#define AML_MP_COMPARE_STRONG(_op_) \
|
|
template<typename U> \
|
|
inline bool operator _op_ (const sptr<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; \
|
|
} \
|
|
/* Needed to handle type inference for nullptr: */ \
|
|
inline bool operator _op_ (const T* o) const { \
|
|
return m_ptr _op_ o; \
|
|
}
|
|
|
|
template<template<typename C> class comparator, typename T, typename U>
|
|
static inline bool _sptr_compare_(T* a, U* b) {
|
|
return comparator<typename std::common_type<T*, U*>::type>()(a, b);
|
|
}
|
|
|
|
// Use std::less and friends to avoid undefined behavior when ordering pointers
|
|
// to different objects.
|
|
#define AML_MP_COMPARE_STRONG_FUNCTIONAL(_op_, _compare_) \
|
|
template<typename U> \
|
|
inline bool operator _op_ (const sptr<U>& o) const { \
|
|
return _sptr_compare_<_compare_>(m_ptr, o.m_ptr); \
|
|
} \
|
|
template<typename U> \
|
|
inline bool operator _op_ (const U* o) const { \
|
|
return _sptr_compare_<_compare_>(m_ptr, o); \
|
|
}
|
|
// ---------------------------------------------------------------------------
|
|
|
|
template<typename T>
|
|
class sptr {
|
|
public:
|
|
inline sptr() : m_ptr(nullptr) { }
|
|
|
|
sptr(T* other); // NOLINT(implicit)
|
|
sptr(const sptr<T>& other);
|
|
sptr(sptr<T>&& other) noexcept;
|
|
template<typename U> sptr(U* other); // NOLINT(implicit)
|
|
template<typename U> sptr(const sptr<U>& other); // NOLINT(implicit)
|
|
template<typename U> sptr(sptr<U>&& other); // NOLINT(implicit)
|
|
|
|
~sptr();
|
|
|
|
// Assignment
|
|
|
|
sptr& operator = (T* other);
|
|
sptr& operator = (const sptr<T>& other);
|
|
sptr& operator=(sptr<T>&& other) noexcept;
|
|
|
|
template<typename U> sptr& operator = (const sptr<U>& other);
|
|
template<typename U> sptr& operator = (sptr<U>&& other);
|
|
template<typename U> sptr& operator = (U* other);
|
|
|
|
//! sptrecial 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; }
|
|
inline explicit operator bool () const { return m_ptr != nullptr; }
|
|
|
|
// Operators
|
|
|
|
AML_MP_COMPARE_STRONG(==)
|
|
AML_MP_COMPARE_STRONG(!=)
|
|
AML_MP_COMPARE_STRONG_FUNCTIONAL(>, std::greater)
|
|
AML_MP_COMPARE_STRONG_FUNCTIONAL(<, std::less)
|
|
AML_MP_COMPARE_STRONG_FUNCTIONAL(<=, std::less_equal)
|
|
AML_MP_COMPARE_STRONG_FUNCTIONAL(>=, std::greater_equal)
|
|
|
|
// Punt these to the wp<> implementation.
|
|
template<typename U>
|
|
inline bool operator == (const wptr<U>& o) const {
|
|
return o == *this;
|
|
}
|
|
|
|
template<typename U>
|
|
inline bool operator != (const wptr<U>& o) const {
|
|
return o != *this;
|
|
}
|
|
|
|
private:
|
|
template<typename Y> friend class sptr;
|
|
template<typename Y> friend class wptr;
|
|
void set_pointer(T* ptr);
|
|
T* m_ptr;
|
|
};
|
|
|
|
// For code size reasons, we do not want this inlined or templated.
|
|
void sptr_report_race();
|
|
|
|
#undef COMPARE
|
|
|
|
// ---------------------------------------------------------------------------
|
|
// No user serviceable parts below here.
|
|
|
|
template<typename T>
|
|
sptr<T>::sptr(T* other)
|
|
: m_ptr(other) {
|
|
if (other)
|
|
other->incStrong(this);
|
|
}
|
|
|
|
template<typename T>
|
|
sptr<T>::sptr(const sptr<T>& other)
|
|
: m_ptr(other.m_ptr) {
|
|
if (m_ptr)
|
|
m_ptr->incStrong(this);
|
|
}
|
|
|
|
template <typename T>
|
|
sptr<T>::sptr(sptr<T>&& other) noexcept : m_ptr(other.m_ptr) {
|
|
other.m_ptr = nullptr;
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>::sptr(U* other)
|
|
: m_ptr(other) {
|
|
if (other)
|
|
(static_cast<T*>(other))->incStrong(this);
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>::sptr(const sptr<U>& other)
|
|
: m_ptr(other.m_ptr) {
|
|
if (m_ptr)
|
|
m_ptr->incStrong(this);
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>::sptr(sptr<U>&& other)
|
|
: m_ptr(other.m_ptr) {
|
|
other.m_ptr = nullptr;
|
|
}
|
|
|
|
template<typename T>
|
|
sptr<T>::~sptr() {
|
|
if (m_ptr)
|
|
m_ptr->decStrong(this);
|
|
}
|
|
|
|
template<typename T>
|
|
sptr<T>& sptr<T>::operator =(const sptr<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)) sptr_report_race();
|
|
m_ptr = otherPtr;
|
|
return *this;
|
|
}
|
|
|
|
template <typename T>
|
|
sptr<T>& sptr<T>::operator=(sptr<T>&& other) noexcept {
|
|
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
|
|
if (oldPtr) oldPtr->decStrong(this);
|
|
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sptr_report_race();
|
|
m_ptr = other.m_ptr;
|
|
other.m_ptr = nullptr;
|
|
return *this;
|
|
}
|
|
|
|
template<typename T>
|
|
sptr<T>& sptr<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)) sptr_report_race();
|
|
m_ptr = other;
|
|
return *this;
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>& sptr<T>::operator =(const sptr<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)) sptr_report_race();
|
|
m_ptr = otherPtr;
|
|
return *this;
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>& sptr<T>::operator =(sptr<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)) sptr_report_race();
|
|
m_ptr = other.m_ptr;
|
|
other.m_ptr = nullptr;
|
|
return *this;
|
|
}
|
|
|
|
template<typename T> template<typename U>
|
|
sptr<T>& sptr<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)) sptr_report_race();
|
|
m_ptr = other;
|
|
return *this;
|
|
}
|
|
|
|
template<typename T>
|
|
void sptr<T>::force_set(T* other) {
|
|
other->forceIncStrong(this);
|
|
m_ptr = other;
|
|
}
|
|
|
|
template<typename T>
|
|
void sptr<T>::clear() {
|
|
T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
|
|
if (oldPtr) {
|
|
oldPtr->decStrong(this);
|
|
if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sptr_report_race();
|
|
m_ptr = nullptr;
|
|
}
|
|
}
|
|
|
|
template<typename T>
|
|
void sptr<T>::set_pointer(T* ptr) {
|
|
m_ptr = ptr;
|
|
}
|
|
|
|
} // namespace android
|
|
|
|
// ---------------------------------------------------------------------------
|
|
|
|
#endif // AML_MP_STRONG_POINTER_H
|