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| -rw-r--r-- | include/osl/mutex.hxx | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/include/osl/mutex.hxx b/include/osl/mutex.hxx new file mode 100644 index 000000000..f984f035c --- /dev/null +++ b/include/osl/mutex.hxx @@ -0,0 +1,253 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you 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 . + */ + +#ifndef INCLUDED_OSL_MUTEX_HXX +#define INCLUDED_OSL_MUTEX_HXX + +#include "osl/mutex.h" + +#include <cassert> + +namespace osl +{ + /** A mutual exclusion synchronization object + */ + class SAL_WARN_UNUSED Mutex { + + public: + /** Create a mutex. + @return 0 if the mutex could not be created, otherwise a handle to the mutex. + @see ::osl_createMutex() + */ + Mutex() + { + mutex = osl_createMutex(); + } + + /** Release the OS-structures and free mutex data-structure. + @see ::osl_destroyMutex() + */ + ~Mutex() + { + osl_destroyMutex(mutex); + } + + /** Acquire the mutex, block if already acquired by another thread. + @return false if system-call fails. + @see ::osl_acquireMutex() + */ + bool acquire() + { + return osl_acquireMutex(mutex); + } + + /** Try to acquire the mutex without blocking. + @return false if it could not be acquired. + @see ::osl_tryToAcquireMutex() + */ + bool tryToAcquire() + { + return osl_tryToAcquireMutex(mutex); + } + + /** Release the mutex. + @return false if system-call fails. + @see ::osl_releaseMutex() + */ + bool release() + { + return osl_releaseMutex(mutex); + } + + /** Returns a global static mutex object. + The global and static mutex object can be used to initialize other + static objects in a thread safe manner. + @return the global mutex object + @see ::osl_getGlobalMutex() + */ + static Mutex * getGlobalMutex() + { + return reinterpret_cast<Mutex *>(osl_getGlobalMutex()); + } + + private: + oslMutex mutex; + + /** The underlying oslMutex has no reference count. + + Since the underlying oslMutex is not a reference counted object, copy + constructed Mutex may work on an already destructed oslMutex object. + + */ + Mutex(const Mutex&) SAL_DELETED_FUNCTION; + + /** This assignment operator is deleted for the same reason as + the copy constructor. + */ + Mutex& operator= (const Mutex&) SAL_DELETED_FUNCTION; + }; + + /** Object lifetime scoped mutex object or interface lock. + * + * Acquires the template object on construction and releases it on + * destruction. + * + * @see MutexGuard + */ + template<class T> + class Guard + { + Guard(const Guard&) SAL_DELETED_FUNCTION; + Guard& operator=(const Guard&) SAL_DELETED_FUNCTION; + + protected: + T * pT; + + public: + /** Acquires the object specified as parameter. + */ + Guard(T * pT_) : pT(pT_) + { + assert(pT != NULL); + pT->acquire(); + } + + /** Acquires the object specified as parameter. + */ + Guard(T & t) : pT(&t) + { + pT->acquire(); + } + + /** Releases the mutex or interface. */ + ~Guard() + { + pT->release(); + } + }; + + /** Object lifetime scoped mutex object or interface lock with unlock. + * + * Use this if you can't use scoped code blocks and Guard. + * + * @see ClearableMutexGuard, Guard + */ + template<class T> + class ClearableGuard + { + ClearableGuard( const ClearableGuard& ) SAL_DELETED_FUNCTION; + ClearableGuard& operator=(const ClearableGuard&) SAL_DELETED_FUNCTION; + + protected: + T * pT; + + public: + /** Acquires the object specified as parameter. + */ + ClearableGuard(T * pT_) : pT(pT_) + { + assert(pT != NULL); + pT->acquire(); + } + + /** Acquires the object specified as parameter. + */ + ClearableGuard(T & t) : pT(&t) + { + pT->acquire(); + } + + /** Releases the mutex or interface if not already released by clear(). + */ + ~ClearableGuard() + { + if (pT) + pT->release(); + } + + /** Releases the mutex or interface. + */ + void clear() + { +#ifdef LIBO_INTERNAL_ONLY + assert(pT); +#else + if (pT) +#endif + { + pT->release(); + pT = NULL; + } + } + }; + + /** Template for temporary releasable mutex objects and interfaces locks. + * + * Use this if you want to acquire a lock but need to temporary release + * it and can't use multiple scoped Guard objects. + * + * @see ResettableMutexGuard + */ + template< class T > + class ResettableGuard : public ClearableGuard< T > + { + ResettableGuard(const ResettableGuard&) SAL_DELETED_FUNCTION; + ResettableGuard& operator=(const ResettableGuard&) SAL_DELETED_FUNCTION; + + protected: + T* pResetT; + + public: + /** Acquires the object specified as parameter. + */ + ResettableGuard( T* pT_ ) : + ClearableGuard<T>( pT_ ), + pResetT( pT_ ) + {} + + /** Acquires the object specified as parameter. + */ + ResettableGuard( T& rT ) : + ClearableGuard<T>( rT ), + pResetT( &rT ) + {} + + /** Re-acquires the mutex or interface. + */ + void reset() + { +#ifdef LIBO_INTERNAL_ONLY + assert(!this->pT); +#endif + if (pResetT) + { + this->pT = pResetT; + this->pT->acquire(); + } + } + }; + + typedef Guard<Mutex> MutexGuard; + typedef ClearableGuard<Mutex> ClearableMutexGuard; + typedef ResettableGuard< Mutex > ResettableMutexGuard; +} + +#endif // INCLUDED_OSL_MUTEX_HXX + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |