/* mutex.h - mutal exclusion locking Copyright (C) Lumiera.org 2008, 2009, Christian Thaeter This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef LUMIERA_MUTEX_H #define LUMIERA_MUTEX_H #include "lib/error.h" #include "lib/sectionlock.h" #include "lib/lockerror.h" #include #include #include /** * @file * Mutual exclusion locking, header. */ /** * Mutual exclusive section. */ #define LUMIERA_MUTEX_SECTION(nobugflag, mtx) \ for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \ lumiera_lock_section_ = { \ mtx, (lumiera_sectionlock_unlock_fn) lumiera_mutex_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ lumiera_lock_section_.lock = \ lumiera_mutex_lock (mtx, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_MUTEX_SECTION_UNLOCK; \ })) /** * Mutual exclusion chainbuilder section. * Usage: LUMIERA_MUTEX_SECTION(a){LUMIERA_MUTEX_SECTION_CHAIN(b){run();}} * calls lock(a); lock(b); unlock(a); run(); unlock(b); * This macro should only be used inside LUMIERA_MUTEX_SECTION and should be * called on the correct mutexes, period. */ #define LUMIERA_MUTEX_SECTION_CHAIN(nobugflag, mtx) \ for (lumiera_sectionlock *lumiera_lock_section_old_ = &lumiera_lock_section_, \ NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) lumiera_lock_section_ = { \ mtx, (lumiera_sectionlock_unlock_fn) lumiera_mutex_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ { \ REQUIRE (lumiera_lock_section_old_->lock, "section prematurely unlocked"); \ lumiera_lock_section_.lock = \ lumiera_mutex_lock (mtx, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ LUMIERA_SECTION_UNLOCK_(lumiera_lock_section_old_); \ } \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_MUTEX_SECTION_UNLOCK; \ })) #define LUMIERA_MUTEX_SECTION_UNLOCK \ LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_) /** * Mutex. * */ struct lumiera_mutex_struct { pthread_mutex_t mutex; RESOURCE_HANDLE (rh); }; typedef struct lumiera_mutex_struct lumiera_mutex; typedef lumiera_mutex* LumieraMutex; /** * Initialize a mutex variable * This initializes a 'fast' default mutex which must not be locked recursively from one thread. * @param self is a pointer to the mutex to be initialized * @param purpose textual hint for the nobug resourcetracker * @param flag nobug logging target * @return self as given */ LumieraMutex lumiera_mutex_init (LumieraMutex self, const char* purpose, struct nobug_flag* flag, const struct nobug_context ctx); /** * Destroy a mutex variable * @param self is a pointer to the mutex to be destroyed * @param flag nobug logging target * @return self as given */ LumieraMutex lumiera_mutex_destroy (LumieraMutex self, struct nobug_flag* flag, const struct nobug_context ctx); /** * Lock a mutex variable * Never fails * @param self is a pointer to the mutex to be destroyed * @param flag nobug logging target * @param handle pointer to nobug user handle (NULL in beta and release builds) * @return self as given */ static inline LumieraMutex lumiera_mutex_lock (LumieraMutex self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_WAIT_CTX (NOBUG_FLAG_RAW(flag), self->rh, "acquire mutex", *handle, ctx) { if (pthread_mutex_lock (&self->mutex)) LUMIERA_DIE (LOCK_ACQUIRE); /* never reached (in a correct program) */ NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } } return self; } /** * Try to lock a mutex variable * @param self is a pointer to the mutex to be destroyed * @param flag nobug logging target * @param handle pointer to nobug user handle (NULL in beta and release builds) * @return self as given or NULL on error, lumiera_error gets set approbiately */ static inline LumieraMutex lumiera_mutex_trylock (LumieraMutex self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "try acquire mutex", *handle, ctx) { int err = pthread_mutex_trylock (&self->mutex); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } /** * Try to lock a mutex variable with a timeout * @param self is a pointer to the mutex to be destroyed * @param timeout timeout for waiting for the lock * @param flag nobug logging target * @param handle pointer to nobug user handle (NULL in beta and release builds) * @return self as given or NULL on error, lumiera_error gets set approbiately */ static inline LumieraMutex lumiera_mutex_timedlock (LumieraMutex self, const struct timespec* timeout, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "timed acquire mutex", *handle, ctx) { int err = pthread_mutex_timedlock (&self->mutex, timeout); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } /** * unlock a mutex variable * Never fails * @param self is a pointer to the mutex to be destroyed * @param flag nobug logging target * @param handle pointer to nobug user handle (NULL in beta and release builds) */ static inline void lumiera_mutex_unlock (LumieraMutex self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { NOBUG_REQUIRE_CTX (self, ctx); NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) { if (pthread_mutex_unlock (&self->mutex)) LUMIERA_DIE (LOCK_RELEASE); /* never reached (in a correct program) */ } } #endif /* // Local Variables: // mode: C // c-file-style: "gnu" // indent-tabs-mode: nil // End: */