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Diffstat (limited to 'opengl/shared/OpenglCodecCommon/SmartPtr.h')
-rw-r--r-- | opengl/shared/OpenglCodecCommon/SmartPtr.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/opengl/shared/OpenglCodecCommon/SmartPtr.h b/opengl/shared/OpenglCodecCommon/SmartPtr.h new file mode 100644 index 0000000..4bdfbe4 --- /dev/null +++ b/opengl/shared/OpenglCodecCommon/SmartPtr.h @@ -0,0 +1,167 @@ +/* +* Copyright (C) 2011 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 __SMART_PTR_H +#define __SMART_PTR_H + +#include <cutils/threads.h> +#include <cutils/atomic.h> + +template <class T, bool threadSafe = false> +class SmartPtr +{ +public: + explicit SmartPtr(T* ptr = (T*)NULL) { + if (threadSafe) { + m_lock = new mutex_t; + mutex_init(m_lock); + } + else m_lock = NULL; + + m_ptr = ptr; + if (ptr) + m_pRefCount = new int32_t(1); + else + m_pRefCount = NULL; + } + + SmartPtr<T,threadSafe>(const SmartPtr<T,false>& rhs) { + if (threadSafe) { + m_lock = new mutex_t; + mutex_init(m_lock); + } + else m_lock = NULL; + + m_pRefCount = rhs.m_pRefCount; + m_ptr = rhs.m_ptr; + use(); + } + + SmartPtr<T,threadSafe>(SmartPtr<T,true>& rhs) { + if (threadSafe) { + m_lock = new mutex_t; + mutex_init(m_lock); + } + else m_lock = NULL; + + if (rhs.m_lock) mutex_lock(rhs.m_lock); + m_pRefCount = rhs.m_pRefCount; + m_ptr = rhs.m_ptr; + use(); + if (rhs.m_lock) mutex_unlock(rhs.m_lock); + } + + ~SmartPtr() { + if (m_lock) mutex_lock(m_lock); + release(); + if (m_lock) + { + mutex_unlock(m_lock); + mutex_destroy(m_lock); + delete m_lock; + } + } + + T* Ptr() const { + return m_ptr; + } + + const T* constPtr() const + { + return m_ptr; + } + + T* operator->() const { + return m_ptr; + } + + T& operator*() const { + return *m_ptr; + } + + operator void*() const { + return (void *)m_ptr; + } + + // This gives STL lists something to compare. + bool operator <(const SmartPtr<T>& t1) const { + return m_ptr < t1.m_ptr; + } + + SmartPtr<T,threadSafe>& operator=(const SmartPtr<T,false>& rhs) + { + if (m_ptr == rhs.m_ptr) + return *this; + + if (m_lock) mutex_lock(m_lock); + release(); + m_pRefCount = rhs.m_pRefCount; + m_ptr = rhs.m_ptr; + use(); + if (m_lock) mutex_unlock(m_lock); + + return *this; + } + + SmartPtr<T,threadSafe>& operator=(SmartPtr<T,true>& rhs) + { + if (m_ptr == rhs.m_ptr) + return *this; + + if (m_lock) mutex_lock(m_lock); + release(); + if (rhs.m_lock) mutex_lock(rhs.m_lock); + m_pRefCount = rhs.m_pRefCount; + m_ptr = rhs.m_ptr; + use(); + if (rhs.m_lock) mutex_unlock(rhs.m_lock); + if (m_lock) mutex_unlock(m_lock); + + return *this; + } + +private: + int32_t *m_pRefCount; + mutex_t *m_lock; + T* m_ptr; + + // Increment the reference count on this pointer by 1. + int use() { + if (!m_pRefCount) return 0; + return android_atomic_inc(m_pRefCount) + 1; + } + + // Decrement the reference count on the pointer by 1. + // If the reference count goes to (or below) 0, the pointer is deleted. + int release() { + if (!m_pRefCount) return 0; + + int iVal = android_atomic_dec(m_pRefCount); + if (iVal > 1) + return iVal - 1; + + delete m_pRefCount; + m_pRefCount = NULL; + + if (m_ptr) { + delete m_ptr; + m_ptr = NULL; + } + return 0; + } + +}; + +#endif // of __SMART_PTR_H |