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Uniform sequence at start of source files - copyright claim - license - file comment - header guard - lumiera includes - library / system includes Lumiera uses Brittish spelling. Add an according note to the styleguide.
261 lines
9.1 KiB
C
261 lines
9.1 KiB
C
/*
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mutex.h - mutal exclusion locking
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Copyright (C) Lumiera.org
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2008, 2009, 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_MUTEX_H
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#define LUMIERA_MUTEX_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 <nobug.h>
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/**
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* @file
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* Mutual exclusion locking, header.
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*/
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/**
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* Mutual exclusive section.
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*/
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#define LUMIERA_MUTEX_SECTION(nobugflag, mtx) \
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for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \
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lumiera_lock_section_ = { \
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mtx, (lumiera_sectionlock_unlock_fn) lumiera_mutex_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_mutex_lock (mtx, &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_MUTEX_SECTION_UNLOCK; \
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}))
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/**
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* Mutual exclusion chainbuilder section.
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* Usage: LUMIERA_MUTEX_SECTION(a){LUMIERA_MUTEX_SECTION_CHAIN(b){run();}}
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* calls lock(a); lock(b); unlock(a); run(); unlock(b);
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* This macro should only be used inside LUMIERA_MUTEX_SECTION and should be
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* called on the correct mutexes, period.
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*/
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#define LUMIERA_MUTEX_SECTION_CHAIN(nobugflag, mtx) \
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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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mtx, (lumiera_sectionlock_unlock_fn) lumiera_mutex_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_mutex_lock (mtx, &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_MUTEX_SECTION_UNLOCK; \
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}))
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#define LUMIERA_MUTEX_SECTION_UNLOCK \
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LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_)
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/**
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* Mutex.
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*
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*/
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struct lumiera_mutex_struct
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{
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pthread_mutex_t mutex;
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RESOURCE_HANDLE (rh);
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};
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typedef struct lumiera_mutex_struct lumiera_mutex;
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typedef lumiera_mutex* LumieraMutex;
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/**
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* Initialise a mutex variable
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* This initialises a 'fast' default mutex which must not be locked recursively from one thread.
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* @param self is a pointer to the mutex to be initialised
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* @param purpose textual hint for the nobug resourcetracker
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* @param flag nobug logging target
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* @return self as given
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*/
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LumieraMutex
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lumiera_mutex_init (LumieraMutex 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 mutex variable
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* @param self is a pointer to the mutex to be destroyed
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* @param flag nobug logging target
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* @return self as given
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*/
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LumieraMutex
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lumiera_mutex_destroy (LumieraMutex 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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* Lock a mutex variable
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* Never fails
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* @param self is a pointer to the mutex to be destroyed
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* @param flag nobug logging target
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* @param handle pointer to nobug user handle (NULL in beta and release builds)
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* @return self as given
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*/
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static inline LumieraMutex
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lumiera_mutex_lock (LumieraMutex 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 mutex", *handle, ctx)
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{
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if (pthread_mutex_lock (&self->mutex))
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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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/**
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* Try to lock a mutex variable
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* @param self is a pointer to the mutex to be destroyed
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* @param flag nobug logging target
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* @param handle pointer to nobug user handle (NULL in beta and release builds)
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* @return self as given or NULL on error, lumiera_error gets set approbiately
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*/
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static inline LumieraMutex
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lumiera_mutex_trylock (LumieraMutex 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 mutex", *handle, ctx)
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{
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int err = pthread_mutex_trylock (&self->mutex);
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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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/**
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* Try to lock a mutex variable with a timeout
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* @param self is a pointer to the mutex to be destroyed
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* @param timeout timeout for waiting for the lock
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* @param flag nobug logging target
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* @param handle pointer to nobug user handle (NULL in beta and release builds)
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* @return self as given or NULL on error, lumiera_error gets set approbiately
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*/
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static inline LumieraMutex
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lumiera_mutex_timedlock (LumieraMutex 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 mutex", *handle, ctx)
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{
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int err = pthread_mutex_timedlock (&self->mutex, 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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/**
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* unlock a mutex variable
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* Never fails
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* @param self is a pointer to the mutex to be destroyed
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* @param flag nobug logging target
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* @param handle pointer to nobug user handle (NULL in beta and release builds)
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*/
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static inline void
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lumiera_mutex_unlock (LumieraMutex 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->mutex))
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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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