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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.
358 lines
13 KiB
C
358 lines
13 KiB
C
/*
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rwlock.h - read/write locks
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Copyright (C) Lumiera.org
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2008, 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_RWLOCK_H
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#define LUMIERA_RWLOCK_H
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#ifndef _GNU_SOURCE
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#error "This header must be included with _GNU_SOURCE or _POSIX_C_SOURCE >= 200112L defined"
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#endif
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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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* Read/write locks, header.
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*/
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/**
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* Read locked section.
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* readlocks may fail when there are too much readers, one has to check the error afterwards!
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*/
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#define LUMIERA_RDLOCK_SECTION(nobugflag, rwlck) \
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for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \
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lumiera_lock_section_ = { \
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rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_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_rwlock_rdlock (rwlck, &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_RWLOCK_SECTION_UNLOCK; \
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}))
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#define LUMIERA_RDLOCK_SECTION_CHAIN(nobugflag, rwlck) \
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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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rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_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_rwlock_rdlock (rwlck, &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_RWLOCK_SECTION_UNLOCK; \
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}))
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/**
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* Write locked section.
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*/
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#define LUMIERA_WRLOCK_SECTION(nobugflag, rwlck) \
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for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \
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lumiera_lock_section_ = { \
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rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_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_rwlock_wrlock (rwlck, &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_RWLOCK_SECTION_UNLOCK; \
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}))
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#define LUMIERA_WRLOCK_SECTION_CHAIN(nobugflag, rwlck) \
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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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rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_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_rwlock_wrlock (rwlck, &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_RWLOCK_SECTION_UNLOCK; \
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}))
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#define LUMIERA_RWLOCK_SECTION_UNLOCK \
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LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_)
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/**
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* RWLock.
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*
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*/
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struct lumiera_rwlock_struct
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{
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pthread_rwlock_t rwlock;
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RESOURCE_HANDLE (rh);
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};
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typedef struct lumiera_rwlock_struct lumiera_rwlock;
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typedef lumiera_rwlock* LumieraRWLock;
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/**
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* Initialize a rwlock
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* @param self is a pointer to the rwlock to be initialised
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* @return self as given
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*/
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LumieraRWLock
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lumiera_rwlock_init (LumieraRWLock 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 rwlock
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* @param self is a pointer to the rwlock to be initialised
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* @return self on success or NULL at error
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*/
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LumieraRWLock
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lumiera_rwlock_destroy (LumieraRWLock self,
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struct nobug_flag* flag,
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const struct nobug_context ctx);
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static inline LumieraRWLock
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lumiera_rwlock_rdlock (LumieraRWLock 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 rwlock for reading", *handle, ctx)
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{
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int err = pthread_rwlock_rdlock (&self->rwlock);
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if (!err)
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{
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NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_SHARED, *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 LumieraRWLock
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lumiera_rwlock_tryrdlock (LumieraRWLock 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 rwlock for reading", *handle, ctx)
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{
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int err = pthread_rwlock_tryrdlock (&self->rwlock);
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if (!err)
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{
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NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_SHARED, *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 LumieraRWLock
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lumiera_rwlock_timedrdlock (LumieraRWLock 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 rwlock for reading", *handle, ctx)
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{
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int err = pthread_rwlock_timedrdlock (&self->rwlock, 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_SHARED, *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 LumieraRWLock
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lumiera_rwlock_wrlock (LumieraRWLock 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 rwlock for writing", *handle, ctx)
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{
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if (pthread_rwlock_wrlock (&self->rwlock))
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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 LumieraRWLock
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lumiera_rwlock_trywrlock (LumieraRWLock 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 rwlock for writing", *handle, ctx)
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{
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int err = pthread_rwlock_trywrlock (&self->rwlock);
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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 LumieraRWLock
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lumiera_rwlock_timedwrlock (LumieraRWLock 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 rwlock for writing", *handle, ctx)
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{
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int err = pthread_rwlock_timedwrlock (&self->rwlock, 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 void
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lumiera_rwlock_unlock (LumieraRWLock 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_rwlock_unlock (&self->rwlock))
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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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