/* condition.h - condition variables Copyright (C) Lumiera.org 2008, 2010, 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_CONDITION_H #define LUMIERA_CONDITION_H #include "lib/error.h" #include "lib/sectionlock.h" #include "lib/lockerror.h" #include #include #include #include /** * @file * Condition variables, header */ /** * Condition section. * Locks the condition mutex, one can use LUMIERA_CONDITION_WAIT to wait for signals or * LUMIERA_CONDITION_SIGNAL or LUMIERA_CONDITION_BROADCAST to wake waiting threads * Condition variables must be at the end of locking chains, they can not be used at * intermediate position. * @param nobugflag NoBug flag used to log actions on the condition * @param cnd Condition variable to be locked */ #define LUMIERA_CONDITION_SECTION(nobugflag, cnd) \ for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \ lumiera_lock_section_ = { \ cnd, (lumiera_sectionlock_unlock_fn) lumiera_condition_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ lumiera_lock_section_.lock = \ lumiera_condition_lock (cnd, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_CONDITION_SECTION_UNLOCK; \ })) #define LUMIERA_CONDITION_SECTION_CHAIN(nobugflag, cnd) \ for (lumiera_sectionlock *lumiera_lock_section_old_ = &lumiera_lock_section_, \ NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) lumiera_lock_section_ = { \ cnd, (lumiera_sectionlock_unlock_fn) lumiera_condition_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_condition_lock (cnd, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ LUMIERA_SECTION_UNLOCK_(lumiera_lock_section_old_); \ } \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_CONDITION_SECTION_UNLOCK; \ })) #define LUMIERA_CONDITION_SECTION_UNLOCK \ LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_) /** * Wait for a condition. * Must be used inside a CONDITION_SECTION. * @param expr Conditon which must become true, else the condition variable goes back into sleep */ #define LUMIERA_CONDITION_WAIT(expr) \ while (!(expr)) { \ REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \ lumiera_condition_wait (lumiera_lock_section_.lock, \ lumiera_lock_section_.flag, \ &lumiera_lock_section_.rh, \ NOBUG_CONTEXT); \ } while (!(expr)) /** * Timed wait for a condition. * Must be used inside a CONDITION_SECTION. * @param expr Conditon which must become true, else the condition variable goes back into sleep * @param timeout time when the wait expired * sets LUMIERA_ERROR_LOCK_TIMEOUT when the timeout passed */ #define LUMIERA_CONDITION_TIMEDWAIT(expr, timeout) \ while (!(expr)) { \ REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \ if (!lumiera_condition_timedwait (lumiera_lock_section_.lock, \ timeout, \ lumiera_lock_section_.flag, \ &lumiera_lock_section_.rh, \ NOBUG_CONTEXT)) \ break; \ } /** * Signal a condition variable * Must be used inside a CONDITION_SECTION. * Wakes one thread waiting on the condition variable */ #define LUMIERA_CONDITION_SIGNAL \ do { \ REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \ lumiera_condition_signal (lumiera_lock_section_.lock, \ lumiera_lock_section_.flag, \ NOBUG_CONTEXT); \ } while (0) /** * Broadcast a condition variable * Must be used inside a CONDITION_SECTION. * Wakes all threads waiting on the condition variable */ #define LUMIERA_CONDITION_BROADCAST \ do { \ REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \ lumiera_condition_broadcast (lumiera_lock_section_.lock, \ lumiera_lock_section_.flag, \ NOBUG_CONTEXT); \ } while (0) /** * Condition variables. * */ struct lumiera_condition_struct { pthread_cond_t cond; pthread_mutex_t cndmutex; RESOURCE_HANDLE (rh); }; typedef struct lumiera_condition_struct lumiera_condition; typedef lumiera_condition* LumieraCondition; /** * Initialise a condition variable * @param self is a pointer to the condition variable to be initialised * @return self as given */ LumieraCondition lumiera_condition_init (LumieraCondition self, const char* purpose, struct nobug_flag* flag, const struct nobug_context ctx); /** * Destroy a condition variable * @param self is a pointer to the condition variable to be destroyed * @return self as given */ LumieraCondition lumiera_condition_destroy (LumieraCondition self, struct nobug_flag* flag, const struct nobug_context ctx); static inline LumieraCondition lumiera_condition_lock (LumieraCondition 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 condvar", *handle, ctx) { if (pthread_mutex_lock (&self->cndmutex)) 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; } static inline LumieraCondition lumiera_condition_trylock (LumieraCondition 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 condvar", *handle, ctx) { int err = pthread_mutex_trylock (&self->cndmutex); 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; } static inline LumieraCondition lumiera_condition_timedlock (LumieraCondition 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 condvar", *handle, ctx) { int err = pthread_mutex_timedlock (&self->cndmutex, 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; } static inline LumieraCondition lumiera_condition_wait (LumieraCondition self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_WAITING, *handle, ctx) { pthread_cond_wait (&self->cond, &self->cndmutex); NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } } return self; } static inline LumieraCondition lumiera_condition_timedwait (LumieraCondition self, const struct timespec* timeout, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_WAITING, *handle, ctx) { int err; do { err = pthread_cond_timedwait (&self->cond, &self->cndmutex, timeout); } while(err == EINTR); NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; if (err) { lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline void lumiera_condition_signal (LumieraCondition self, struct nobug_flag* flag, const struct nobug_context ctx) { NOBUG_TRACE_CTX (NOBUG_FLAG_RAW(flag), ctx, "Signal %p", self); pthread_cond_signal (&self->cond); } static inline void lumiera_condition_broadcast (LumieraCondition self, struct nobug_flag* flag, const struct nobug_context ctx) { NOBUG_TRACE_CTX(NOBUG_FLAG_RAW(flag), ctx, "Broadcast %p", self); pthread_cond_broadcast (&self->cond); } static inline void lumiera_condition_unlock (LumieraCondition 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->cndmutex)) LUMIERA_DIE (LOCK_RELEASE); /* never reached (in a correct program) */ } } #endif /* // Local Variables: // mode: C // c-file-style: "gnu" // indent-tabs-mode: nil // End: */