mpd/src/thread/PosixMutex.hxx

77 lines
2.2 KiB
C++

/*
* Copyright (C) 2009-2013 Max Kellermann <max@duempel.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef THREAD_POSIX_MUTEX_HXX
#define THREAD_POSIX_MUTEX_HXX
#include <pthread.h>
/**
* Low-level wrapper for a pthread_mutex_t.
*/
class PosixMutex {
friend class PosixCond;
pthread_mutex_t mutex;
public:
#ifdef __GLIBC__
/* optimized constexpr constructor for pthread implementations
that support it */
constexpr PosixMutex():mutex(PTHREAD_MUTEX_INITIALIZER) {}
#else
/* slow fallback for pthread implementations that are not
compatible with "constexpr" */
PosixMutex() {
pthread_mutex_init(&mutex, nullptr);
}
~PosixMutex() {
pthread_mutex_destroy(&mutex);
}
#endif
PosixMutex(const PosixMutex &other) = delete;
PosixMutex &operator=(const PosixMutex &other) = delete;
void lock() {
pthread_mutex_lock(&mutex);
}
bool try_lock() {
return pthread_mutex_trylock(&mutex) == 0;
}
void unlock() {
pthread_mutex_unlock(&mutex);
}
};
#endif