/* This file is part of the YAZ toolkit. * Copyright (C) Index Data. * All rights reserved. * 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. * * Neither the name of Index Data nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS AND 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. */ /** * \file mutex.h * \brief Header for Mutex functions */ #ifndef YAZ_MUTEX_H #define YAZ_MUTEX_H #include <stddef.h> #include <time.h> #include <yaz/yconfig.h> YAZ_BEGIN_CDECL /** \brief YAZ MUTEX opaque pointer */ typedef struct yaz_mutex *YAZ_MUTEX; /** \brief YAZ condition opaque pointer */ typedef struct yaz_cond *YAZ_COND; /** \brief create MUTEX \param mutexp is pointer to MUTEX handle (*mutexp must be NULL) It is important that *mutexp is NULL. If not, yaz_mutex_create will not modify the handle (assumes it is already created!) */ YAZ_EXPORT void yaz_mutex_create(YAZ_MUTEX *mutexp); /** \brief enter critical section / AKA lock \param mutex MUTEX handle */ YAZ_EXPORT void yaz_mutex_enter(YAZ_MUTEX mutex); /** \brief leave critical section / AKA unlock \param mutex MUTEX handle */ YAZ_EXPORT void yaz_mutex_leave(YAZ_MUTEX mutex); /** \brief destroy MUTEX \param mutexp pointer to MUTEX handle If *mutexp is NULL, then this function does nothing. */ YAZ_EXPORT void yaz_mutex_destroy(YAZ_MUTEX *mutexp); /** \brief sets name of MUTEX for debugging purposes \param mutex MUTEX handle \param log_level YAZ log level \param name user-given name associated with MUTEX If log_level != 0 and name != 0 this function will make yaz_mutex_enter and yaz_mutex_leave print information for each invocation using yaz_log with the level given. In particular when YAZ is compiled with pthreads, yaz_mutex_enter will inform if a lock is not immediately acquired. This function should be called after a MUTEX is created but before it is used for locking. */ YAZ_EXPORT void yaz_mutex_set_name(YAZ_MUTEX mutex, int log_level, const char *name); /** \brief creates condition variable \param p reference to condition handle Upon successful completion *p holds the condition handle; *p = 0 on error. */ YAZ_EXPORT void yaz_cond_create(YAZ_COND *p); /** \brief destroys condition variable \param p reference to condition handle Upon completion *p holds 0. */ YAZ_EXPORT void yaz_cond_destroy(YAZ_COND *p); struct timeval; /** \brief waits for condition \param p condition variable handle \param m mutex \param abstime wait until this time; 0 for indefinite wait Semantics like pthread_cond_wait. */ YAZ_EXPORT int yaz_cond_wait(YAZ_COND p, YAZ_MUTEX m, const struct timeval *abstime); /** \brief unblock one thread waiting for block \param p condition variable handle */ YAZ_EXPORT int yaz_cond_signal(YAZ_COND p); /** \brief unblock all threads waiting for block \param p condition variable handle */ YAZ_EXPORT int yaz_cond_broadcast(YAZ_COND p); YAZ_END_CDECL #endif /* * Local variables: * c-basic-offset: 4 * c-file-style: "Stroustrup" * indent-tabs-mode: nil * End: * vim: shiftwidth=4 tabstop=8 expandtab */