362 lines
13 KiB
C
362 lines
13 KiB
C
/*
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condition.h - condition variables
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Copyright (C) Lumiera.org
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2008, 2010, Christian Thaeter <ct@pipapo.org>
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef LUMIERA_CONDITION_H
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#define LUMIERA_CONDITION_H
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#include "lib/error.h"
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#include "lib/sectionlock.h"
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#include "lib/lockerror.h"
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#include <pthread.h>
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#include <time.h>
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#include <errno.h>
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#include <nobug.h>
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/**
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* @file
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* Condition variables, header
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*/
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/**
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* Condition section.
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* Locks the condition mutex, one can use LUMIERA_CONDITION_WAIT to wait for signals or
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* LUMIERA_CONDITION_SIGNAL or LUMIERA_CONDITION_BROADCAST to wake waiting threads
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* Condition variables must be at the end of locking chains, they can not be used at
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* intermediate position.
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* @param nobugflag NoBug flag used to log actions on the condition
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* @param cnd Condition variable to be locked
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*/
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#define LUMIERA_CONDITION_SECTION(nobugflag, cnd) \
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for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \
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lumiera_lock_section_ = { \
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cnd, (lumiera_sectionlock_unlock_fn) lumiera_condition_unlock \
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NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \
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({ \
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if (lumiera_lock_section_.lock) \
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lumiera_lock_section_.lock = \
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lumiera_condition_lock (cnd, &NOBUG_FLAG(nobugflag), \
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&lumiera_lock_section_.rh, NOBUG_CONTEXT); \
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lumiera_lock_section_.lock; \
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}); \
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({ \
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LUMIERA_CONDITION_SECTION_UNLOCK; \
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}))
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#define LUMIERA_CONDITION_SECTION_CHAIN(nobugflag, cnd) \
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for (lumiera_sectionlock *lumiera_lock_section_old_ = &lumiera_lock_section_, \
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NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) lumiera_lock_section_ = { \
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cnd, (lumiera_sectionlock_unlock_fn) lumiera_condition_unlock \
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NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \
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({ \
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if (lumiera_lock_section_.lock) \
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{ \
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REQUIRE (lumiera_lock_section_old_->lock, "section prematurely unlocked"); \
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lumiera_lock_section_.lock = \
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lumiera_condition_lock (cnd, &NOBUG_FLAG(nobugflag), \
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&lumiera_lock_section_.rh, NOBUG_CONTEXT); \
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LUMIERA_SECTION_UNLOCK_(lumiera_lock_section_old_); \
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} \
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lumiera_lock_section_.lock; \
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}); \
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({ \
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LUMIERA_CONDITION_SECTION_UNLOCK; \
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}))
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#define LUMIERA_CONDITION_SECTION_UNLOCK \
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LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_)
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/**
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* Wait for a condition.
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* Must be used inside a CONDITION_SECTION.
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* @param expr Conditon which must become true, else the condition variable goes back into sleep
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*/
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#define LUMIERA_CONDITION_WAIT(expr) \
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while (!(expr)) { \
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REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \
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lumiera_condition_wait (lumiera_lock_section_.lock, \
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lumiera_lock_section_.flag, \
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&lumiera_lock_section_.rh, \
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NOBUG_CONTEXT); \
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} while (!(expr))
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/**
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* Timed wait for a condition.
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* Must be used inside a CONDITION_SECTION.
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* @param expr Conditon which must become true, else the condition variable goes back into sleep
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* @param timeout time when the wait expired
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* sets LUMIERA_ERROR_LOCK_TIMEOUT when the timeout passed
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*/
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#define LUMIERA_CONDITION_TIMEDWAIT(expr, timeout) \
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while (!(expr)) { \
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REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \
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if (!lumiera_condition_timedwait (lumiera_lock_section_.lock, \
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timeout, \
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lumiera_lock_section_.flag, \
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&lumiera_lock_section_.rh, \
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NOBUG_CONTEXT)) \
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break; \
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}
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/**
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* Signal a condition variable
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* Must be used inside a CONDITION_SECTION.
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* Wakes one thread waiting on the condition variable
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*/
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#define LUMIERA_CONDITION_SIGNAL \
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do { \
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REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \
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lumiera_condition_signal (lumiera_lock_section_.lock, \
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lumiera_lock_section_.flag, \
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NOBUG_CONTEXT); \
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} while (0)
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/**
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* Broadcast a condition variable
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* Must be used inside a CONDITION_SECTION.
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* Wakes all threads waiting on the condition variable
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*/
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#define LUMIERA_CONDITION_BROADCAST \
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do { \
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REQUIRE (lumiera_lock_section_.lock, "Condition mutex not locked"); \
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lumiera_condition_broadcast (lumiera_lock_section_.lock, \
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lumiera_lock_section_.flag, \
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NOBUG_CONTEXT); \
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} while (0)
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/**
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* Condition variables.
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*
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*/
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struct lumiera_condition_struct
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{
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pthread_cond_t cond;
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pthread_mutex_t cndmutex;
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RESOURCE_HANDLE (rh);
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};
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typedef struct lumiera_condition_struct lumiera_condition;
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typedef lumiera_condition* LumieraCondition;
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/**
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* Initialize a condition variable
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* @param self is a pointer to the condition variable to be initialized
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* @return self as given
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*/
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LumieraCondition
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lumiera_condition_init (LumieraCondition self,
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const char* purpose,
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struct nobug_flag* flag,
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const struct nobug_context ctx);
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/**
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* Destroy a condition variable
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* @param self is a pointer to the condition variable to be destroyed
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* @return self as given
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*/
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LumieraCondition
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lumiera_condition_destroy (LumieraCondition self,
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struct nobug_flag* flag,
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const struct nobug_context ctx);
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static inline LumieraCondition
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lumiera_condition_lock (LumieraCondition self,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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if (self)
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{
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NOBUG_RESOURCE_WAIT_CTX (NOBUG_FLAG_RAW(flag), self->rh, "acquire condvar", *handle, ctx)
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{
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if (pthread_mutex_lock (&self->cndmutex))
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LUMIERA_DIE (LOCK_ACQUIRE); /* never reached (in a correct program) */
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NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/;
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}
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}
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return self;
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}
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static inline LumieraCondition
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lumiera_condition_trylock (LumieraCondition self,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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if (self)
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{
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NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "try acquire condvar", *handle, ctx)
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{
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int err = pthread_mutex_trylock (&self->cndmutex);
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if (!err)
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{
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NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/;
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}
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else
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{
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NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/;
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lumiera_lockerror_set (err, flag, ctx);
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self = NULL;
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}
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}
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}
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return self;
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}
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static inline LumieraCondition
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lumiera_condition_timedlock (LumieraCondition self,
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const struct timespec* timeout,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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if (self)
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{
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NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "timed acquire condvar", *handle, ctx)
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{
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int err = pthread_mutex_timedlock (&self->cndmutex, timeout);
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if (!err)
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{
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NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/;
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}
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else
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{
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NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/;
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lumiera_lockerror_set (err, flag, ctx);
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self = NULL;
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}
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}
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}
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return self;
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}
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static inline LumieraCondition
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lumiera_condition_wait (LumieraCondition self,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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if (self)
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{
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NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_WAITING, *handle, ctx)
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{
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pthread_cond_wait (&self->cond, &self->cndmutex);
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NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/;
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}
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}
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return self;
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}
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static inline LumieraCondition
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lumiera_condition_timedwait (LumieraCondition self,
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const struct timespec* timeout,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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if (self)
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{
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NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_WAITING, *handle, ctx)
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{
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int err;
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do {
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err = pthread_cond_timedwait (&self->cond, &self->cndmutex, timeout);
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} while(err == EINTR);
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NOBUG_RESOURCE_STATE_RAW_CTX (flag, NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/;
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if (err)
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{
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lumiera_lockerror_set (err, flag, ctx);
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self = NULL;
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}
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}
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}
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return self;
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}
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static inline void
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lumiera_condition_signal (LumieraCondition self,
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struct nobug_flag* flag,
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const struct nobug_context ctx)
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{
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NOBUG_TRACE_CTX (NOBUG_FLAG_RAW(flag), ctx, "Signal %p", self);
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pthread_cond_signal (&self->cond);
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}
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static inline void
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lumiera_condition_broadcast (LumieraCondition self,
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struct nobug_flag* flag,
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const struct nobug_context ctx)
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{
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NOBUG_TRACE_CTX(NOBUG_FLAG_RAW(flag), ctx, "Broadcast %p", self);
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pthread_cond_broadcast (&self->cond);
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}
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static inline void
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lumiera_condition_unlock (LumieraCondition self,
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struct nobug_flag* flag,
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struct nobug_resource_user** handle,
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const struct nobug_context ctx)
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{
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NOBUG_REQUIRE_CTX (self, ctx);
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NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx)
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{
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if (pthread_mutex_unlock (&self->cndmutex))
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LUMIERA_DIE (LOCK_RELEASE); /* never reached (in a correct program) */
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}
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}
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#endif
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/*
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// Local Variables:
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// mode: C
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// c-file-style: "gnu"
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// indent-tabs-mode: nil
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// End:
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*/
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