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      1 #ifndef _DEMUTEX_HPP
      2 #define _DEMUTEX_HPP
      3 /*-------------------------------------------------------------------------
      4  * drawElements C++ Base Library
      5  * -----------------------------
      6  *
      7  * Copyright 2014 The Android Open Source Project
      8  *
      9  * Licensed under the Apache License, Version 2.0 (the "License");
     10  * you may not use this file except in compliance with the License.
     11  * You may obtain a copy of the License at
     12  *
     13  *      http://www.apache.org/licenses/LICENSE-2.0
     14  *
     15  * Unless required by applicable law or agreed to in writing, software
     16  * distributed under the License is distributed on an "AS IS" BASIS,
     17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     18  * See the License for the specific language governing permissions and
     19  * limitations under the License.
     20  *
     21  *//*!
     22  * \file
     23  * \brief deMutex C++ wrapper.
     24  *//*--------------------------------------------------------------------*/
     25 
     26 #include "deDefs.hpp"
     27 #include "deMutex.h"
     28 
     29 namespace de
     30 {
     31 
     32 /*--------------------------------------------------------------------*//*!
     33  * \brief Mutual exclusion lock
     34  *
     35  * Mutex class provides standard mutual exclusion lock functionality.
     36  *//*--------------------------------------------------------------------*/
     37 class Mutex
     38 {
     39 public:
     40 					Mutex			(deUint32 flags = 0);
     41 					~Mutex			(void);
     42 
     43 	void			lock			(void) throw();
     44 	void			unlock			(void) throw();
     45 	bool			tryLock			(void) throw();
     46 
     47 private:
     48 					Mutex			(const Mutex& other); // Not allowed!
     49 	Mutex&			operator=		(const Mutex& other); // Not allowed!
     50 
     51 	deMutex			m_mutex;
     52 };
     53 
     54 /*--------------------------------------------------------------------*//*!
     55  * \brief Scoped mutex lock.
     56  *
     57  * ScopedLock provides helper for maintaining Mutex lock for the duration
     58  * of current scope. The lock is acquired in constructor and released
     59  * when ScopedLock goes out of scope.
     60  *//*--------------------------------------------------------------------*/
     61 class ScopedLock
     62 {
     63 public:
     64 					ScopedLock		(Mutex& mutex);
     65 					~ScopedLock		(void) { m_mutex.unlock(); }
     66 
     67 private:
     68 					ScopedLock		(const ScopedLock& other); // Not allowed!
     69 	ScopedLock&		operator=		(const ScopedLock& other); // Not allowed!
     70 
     71 	Mutex&			m_mutex;
     72 };
     73 
     74 // Mutex inline implementations.
     75 
     76 /*--------------------------------------------------------------------*//*!
     77  * \brief Acquire mutex lock.
     78  * \note This method will never report failure. If an error occurs due
     79  *		 to misuse or other reason it will lead to process termination
     80 *		 in debug build.
     81  *
     82  * If mutex is currently locked the function will block until current
     83  * lock is released.
     84  *
     85  * In recursive mode further calls from the thread owning the mutex will
     86  * succeed and increment lock count.
     87  *//*--------------------------------------------------------------------*/
     88 inline void Mutex::lock (void) throw()
     89 {
     90 	deMutex_lock(m_mutex);
     91 }
     92 
     93 /*--------------------------------------------------------------------*//*!
     94  * \brief Release mutex lock.
     95  * \note This method will never report failure. If an error occurs due
     96  *		 to misuse or other reason it will lead to process termination
     97 *		 in debug build.
     98  *
     99  * In recursive mode the mutex will be released once the lock count reaches
    100  * zero.
    101  *//*--------------------------------------------------------------------*/
    102 inline void Mutex::unlock (void) throw()
    103 {
    104 	deMutex_unlock(m_mutex);
    105 }
    106 
    107 /*--------------------------------------------------------------------*//*!
    108  * \brief Try to acquire lock.
    109  * \return Returns true if lock was acquired and false otherwise.
    110  *
    111  * This function will never block, i.e. it will return false if mutex
    112  * is currently locked.
    113  *//*--------------------------------------------------------------------*/
    114 inline bool Mutex::tryLock (void) throw()
    115 {
    116 	return deMutex_tryLock(m_mutex) == DE_TRUE;
    117 }
    118 
    119 // ScopedLock inline implementations.
    120 
    121 /*--------------------------------------------------------------------*//*!
    122  * \brief Acquire scoped lock to mutex.
    123  * \param mutex Mutex to be locked.
    124  *//*--------------------------------------------------------------------*/
    125 inline ScopedLock::ScopedLock (Mutex& mutex)
    126 	: m_mutex(mutex)
    127 {
    128 	m_mutex.lock();
    129 }
    130 
    131 } // de
    132 
    133 #endif // _DEMUTEX_HPP
    134