mirror of
https://git.rtems.org/rtems-libbsd/
synced 2025-10-16 02:23:41 +08:00
RWLOCK(9): Add reader/writer lock implementation
This commit is contained in:
Sebastian Huber
60
rtemsbsd/include/machine/rtems-bsd-rwlock.h
Normal file
60
rtemsbsd/include/machine/rtems-bsd-rwlock.h
Normal file
@@ -0,0 +1,60 @@
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/**
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* @file
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*
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* @ingroup rtems_bsd_machine
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*
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* @brief TODO.
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*/
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/*
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* Copyright (c) 2017 embedded brains GmbH. All rights reserved.
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*
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* embedded brains GmbH
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* Dornierstr. 4
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* 82178 Puchheim
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* Germany
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* <rtems@embedded-brains.de>
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*
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* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
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||||
*/
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#ifndef _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_
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#define _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_
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#include <rtems/score/threadq.h>
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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typedef struct {
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Thread_queue_Control writer_queue;
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Thread_queue_Control reader_queue;
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int readers;
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int nest_level;
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} rtems_bsd_rwlock;
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#ifdef __cplusplus
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}
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#endif /* __cplusplus */
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#endif /* _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCK_H_ */
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429
rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h
Normal file
429
rtemsbsd/include/machine/rtems-bsd-rwlockimpl.h
Normal file
@@ -0,0 +1,429 @@
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/**
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* @file
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*
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* @ingroup rtems_bsd_machine
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*
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* @brief Implementation of a reader/writer lock with priority inheritance for
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* exclusive owners (writer).
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*/
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/*
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* Copyright (c) 2017 embedded brains GmbH. All rights reserved.
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*
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* embedded brains GmbH
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* Dornierstr. 4
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* 82178 Puchheim
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* Germany
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||||
* <rtems@embedded-brains.de>
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||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
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||||
*/
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#ifndef _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_
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#define _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_
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#include <machine/rtems-bsd-rwlock.h>
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#include <machine/rtems-bsd-support.h>
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#include <sys/types.h>
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#include <sys/lock.h>
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#include <rtems/score/threadimpl.h>
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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typedef struct {
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Thread_queue_Context writer;
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Thread_queue_Context reader;
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} rtems_bsd_rwlock_context;
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static inline void
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rtems_bsd_rwlock_context_init(rtems_bsd_rwlock_context *context)
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{
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_Thread_queue_Context_initialize(&context->writer);
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}
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static inline void
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rtems_bsd_rwlock_init(struct lock_object *lock, rtems_bsd_rwlock *rw,
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struct lock_class *class, const char *name, const char *type, int flags)
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{
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_Thread_queue_Initialize(&rw->writer_queue, name);
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_Thread_queue_Initialize(&rw->reader_queue, name);
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rw->readers = 0;
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rw->nest_level = 0;
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lock_init(lock, class, name, type, flags);
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}
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void rtems_bsd_rwlock_wlock_more(const struct lock_object *lock,
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rtems_bsd_rwlock *rw, Thread_Control *executing,
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rtems_bsd_rwlock_context *context);
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void rtems_bsd_rwlock_wunlock_more(rtems_bsd_rwlock *rw,
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Thread_Control *wowner, rtems_bsd_rwlock_context *context);
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void rtems_bsd_rwlock_rlock_more(rtems_bsd_rwlock *rw,
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rtems_bsd_rwlock_context *context);
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void rtems_bsd_rwlock_runlock_more(rtems_bsd_rwlock *rw,
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rtems_bsd_rwlock_context *context);
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void rtems_bsd_rwlock_ready_waiting_readers(rtems_bsd_rwlock *rw,
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rtems_bsd_rwlock_context *context);
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#define rtems_bsd_rwlock_isr_disable(isr_level, context) \
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do { \
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_ISR_Local_disable(isr_level); \
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_ISR_lock_ISR_disable_profile( \
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&(context)->writer.Lock_context.Lock_context) \
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} while (0)
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static inline void
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rtems_bsd_rwlock_acquire_critical(rtems_bsd_rwlock *rw,
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rtems_bsd_rwlock_context *context)
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{
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_Thread_queue_Queue_acquire_critical(&rw->writer_queue.Queue,
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&rw->writer_queue.Lock_stats,
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&context->writer.Lock_context.Lock_context);
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#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG)
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rw->writer_queue.owner = _SMP_lock_Who_am_I();
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#endif
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}
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static inline void
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rtems_bsd_rwlock_release(rtems_bsd_rwlock *rw, ISR_Level isr_level,
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rtems_bsd_rwlock_context *context)
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{
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#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG)
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_Assert( _Thread_queue_Is_lock_owner( &rw->writer_queue ) );
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rw->writer_queue.owner = SMP_LOCK_NO_OWNER;
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#endif
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_Thread_queue_Queue_release_critical(&rw->writer_queue.Queue,
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&context->writer.Lock_context.Lock_context);
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_ISR_Local_enable(isr_level);
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}
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static inline void
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rtems_bsd_rwlock_set_isr_level(rtems_bsd_rwlock_context *context,
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ISR_Level isr_level)
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{
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_ISR_lock_Context_set_level(&context->writer.Lock_context.Lock_context,
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isr_level);
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}
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static inline Thread_Control *
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rtems_bsd_rwlock_wowner(const rtems_bsd_rwlock *rw)
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{
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return (rw->writer_queue.Queue.owner);
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}
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static inline void
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rtems_bsd_rwlock_set_wowner(rtems_bsd_rwlock *rw, Thread_Control *wowner)
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{
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rw->writer_queue.Queue.owner = wowner;
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}
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static inline void
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rtems_bsd_rwlock_wlock(struct lock_object *lock, rtems_bsd_rwlock *rw)
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{
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ISR_Level isr_level;
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rtems_bsd_rwlock_context context;
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Thread_Control *executing;
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rtems_bsd_rwlock_context_init(&context);
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rtems_bsd_rwlock_isr_disable(isr_level, &context);
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executing = _Thread_Executing;
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rtems_bsd_rwlock_acquire_critical(rw, &context);
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if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL &&
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rw->readers == 0)) {
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rtems_bsd_rwlock_set_wowner(rw, executing);
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_Thread_Resource_count_increment(executing);
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rtems_bsd_rwlock_release(rw, isr_level, &context);
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} else {
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rtems_bsd_rwlock_set_isr_level(&context, isr_level);
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rtems_bsd_rwlock_wlock_more(lock, rw, executing,
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&context);
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}
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}
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static inline int
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rtems_bsd_rwlock_try_wlock(struct lock_object *lock, rtems_bsd_rwlock *rw)
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{
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int success;
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ISR_Level isr_level;
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rtems_bsd_rwlock_context context;
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Thread_Control *executing;
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rtems_bsd_rwlock_context_init(&context);
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rtems_bsd_rwlock_isr_disable(isr_level, &context);
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executing = _Thread_Executing;
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rtems_bsd_rwlock_acquire_critical(rw, &context);
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if (rw->readers == 0) {
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Thread_Control *wowner;
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wowner = rtems_bsd_rwlock_wowner(rw);
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if (wowner == NULL) {
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rtems_bsd_rwlock_set_wowner(rw, executing);
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_Thread_Resource_count_increment(executing);
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success = 1;
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} else if (wowner == executing) {
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BSD_ASSERT(lock->lo_flags & LO_RECURSABLE);
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++rw->nest_level;
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success = 1;
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} else {
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success = 0;
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}
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} else {
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success = 0;
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}
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rtems_bsd_rwlock_release(rw, isr_level, &context);
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return (success);
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}
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static inline void
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rtems_bsd_rwlock_wunlock(rtems_bsd_rwlock *rw)
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{
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ISR_Level isr_level;
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rtems_bsd_rwlock_context context;
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Thread_Control *wowner;
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int nest_level;
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rtems_bsd_rwlock_context_init(&context);
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rtems_bsd_rwlock_isr_disable(isr_level, &context);
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rtems_bsd_rwlock_acquire_critical(rw, &context);
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nest_level = rw->nest_level;
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wowner = rtems_bsd_rwlock_wowner(rw);
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BSD_ASSERT(wowner == _Thread_Executing);
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if (__predict_true(nest_level == 0)) {
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rtems_bsd_rwlock_set_wowner(rw, NULL);
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_Thread_Resource_count_decrement(wowner);
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if (__predict_true(
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_Thread_queue_Is_empty(&rw->writer_queue.Queue) &&
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_Thread_queue_Is_empty(&rw->reader_queue.Queue))) {
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rtems_bsd_rwlock_release(rw, isr_level, &context);
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} else {
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rtems_bsd_rwlock_set_isr_level(&context,
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isr_level);
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rtems_bsd_rwlock_wunlock_more(rw, wowner,
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&context);
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}
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} else {
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rw->nest_level = nest_level - 1;
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rtems_bsd_rwlock_release(rw, isr_level, &context);
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}
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}
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static inline int
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rtems_bsd_rwlock_wowned(const rtems_bsd_rwlock *rw)
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{
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return (rtems_bsd_rwlock_wowner(rw) == _Thread_Get_executing());
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}
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static inline int
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rtems_bsd_rwlock_recursed(const rtems_bsd_rwlock *rw)
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{
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return (rw->nest_level != 0);
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}
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static inline void
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rtems_bsd_rwlock_rlock(struct lock_object *lock, rtems_bsd_rwlock *rw)
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{
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ISR_Level isr_level;
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rtems_bsd_rwlock_context context;
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rtems_bsd_rwlock_context_init(&context);
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rtems_bsd_rwlock_isr_disable(isr_level, &context);
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rtems_bsd_rwlock_acquire_critical(rw, &context);
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if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL &&
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_Thread_queue_Is_empty(&rw->writer_queue.Queue))) {
|
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++rw->readers;
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_Thread_Resource_count_increment(_Thread_Executing);
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rtems_bsd_rwlock_release(rw, isr_level, &context);
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} else {
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rtems_bsd_rwlock_set_isr_level(&context, isr_level);
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rtems_bsd_rwlock_rlock_more(rw, &context);
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}
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}
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static inline int
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rtems_bsd_rwlock_try_rlock(struct lock_object *lock, rtems_bsd_rwlock *rw)
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{
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int success;
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ISR_Level isr_level;
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rtems_bsd_rwlock_context context;
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rtems_bsd_rwlock_context_init(&context);
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rtems_bsd_rwlock_isr_disable(isr_level, &context);
|
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rtems_bsd_rwlock_acquire_critical(rw, &context);
|
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|
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if (__predict_true(rtems_bsd_rwlock_wowner(rw) == NULL &&
|
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_Thread_queue_Is_empty(&rw->writer_queue.Queue))) {
|
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++rw->readers;
|
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_Thread_Resource_count_increment(_Thread_Executing);
|
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success = 1;
|
||||
} else {
|
||||
success = 0;
|
||||
}
|
||||
|
||||
rtems_bsd_rwlock_release(rw, isr_level, &context);
|
||||
|
||||
return (success);
|
||||
}
|
||||
|
||||
static inline void
|
||||
rtems_bsd_rwlock_runlock(rtems_bsd_rwlock *rw)
|
||||
{
|
||||
ISR_Level isr_level;
|
||||
rtems_bsd_rwlock_context context;
|
||||
int readers;
|
||||
|
||||
rtems_bsd_rwlock_context_init(&context);
|
||||
rtems_bsd_rwlock_isr_disable(isr_level, &context);
|
||||
rtems_bsd_rwlock_acquire_critical(rw, &context);
|
||||
|
||||
readers = rw->readers;
|
||||
_Thread_Resource_count_decrement(_Thread_Executing);
|
||||
|
||||
if (__predict_true(readers == 1)) {
|
||||
rw->readers = 0;
|
||||
|
||||
if (__predict_true(
|
||||
_Thread_queue_Is_empty(&rw->writer_queue.Queue) &&
|
||||
_Thread_queue_Is_empty(&rw->reader_queue.Queue))) {
|
||||
rtems_bsd_rwlock_release(rw, isr_level,
|
||||
&context);
|
||||
} else {
|
||||
rtems_bsd_rwlock_set_isr_level(&context,
|
||||
isr_level);
|
||||
rtems_bsd_rwlock_runlock_more(rw, &context);
|
||||
}
|
||||
} else {
|
||||
rw->readers = readers - 1;
|
||||
rtems_bsd_rwlock_release(rw, isr_level, &context);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int
|
||||
rtems_bsd_rwlock_try_upgrade(rtems_bsd_rwlock *rw)
|
||||
{
|
||||
int success;
|
||||
ISR_Level isr_level;
|
||||
rtems_bsd_rwlock_context context;
|
||||
Thread_Control *executing;
|
||||
Thread_Control *wowner;
|
||||
|
||||
rtems_bsd_rwlock_context_init(&context);
|
||||
rtems_bsd_rwlock_isr_disable(isr_level, &context);
|
||||
executing = _Thread_Executing;
|
||||
rtems_bsd_rwlock_acquire_critical(rw, &context);
|
||||
|
||||
wowner = rtems_bsd_rwlock_wowner(rw);
|
||||
BSD_ASSERT(wowner == NULL);
|
||||
|
||||
if (rw->readers == 1) {
|
||||
rw->readers = 0;
|
||||
rtems_bsd_rwlock_set_wowner(rw, executing);
|
||||
/* FIXME: priority inheritance */
|
||||
success = 1;
|
||||
} else {
|
||||
success = 0;
|
||||
}
|
||||
|
||||
rtems_bsd_rwlock_release(rw, isr_level, &context);
|
||||
|
||||
return (success);
|
||||
}
|
||||
|
||||
static inline void
|
||||
rtems_bsd_rwlock_downgrade(rtems_bsd_rwlock *rw)
|
||||
{
|
||||
ISR_Level isr_level;
|
||||
rtems_bsd_rwlock_context context;
|
||||
Thread_Control *wowner;
|
||||
|
||||
rtems_bsd_rwlock_context_init(&context);
|
||||
rtems_bsd_rwlock_isr_disable(isr_level, &context);
|
||||
rtems_bsd_rwlock_acquire_critical(rw, &context);
|
||||
|
||||
wowner = rtems_bsd_rwlock_wowner(rw);
|
||||
|
||||
BSD_ASSERT(wowner == _Thread_Executing);
|
||||
BSD_ASSERT(rw->nest_level == 0);
|
||||
|
||||
rtems_bsd_rwlock_set_wowner(rw, NULL);
|
||||
rw->readers = 1;
|
||||
|
||||
if (__predict_true(_Thread_queue_Is_empty(&rw->reader_queue.Queue))) {
|
||||
rtems_bsd_rwlock_release(rw, isr_level, &context);
|
||||
} else {
|
||||
rtems_bsd_rwlock_set_isr_level(&context, isr_level);
|
||||
rtems_bsd_rwlock_ready_waiting_readers(rw, &context);
|
||||
}
|
||||
}
|
||||
|
||||
static inline const char *
|
||||
rtems_bsd_rwlock_name(const rtems_bsd_rwlock *rw)
|
||||
{
|
||||
|
||||
return (rw->writer_queue.Queue.name);
|
||||
}
|
||||
|
||||
static inline void
|
||||
rtems_bsd_rwlock_destroy(struct lock_object *lock, rtems_bsd_rwlock *rw)
|
||||
{
|
||||
BSD_ASSERT(_Thread_queue_Is_empty(&rw->writer_queue.Queue));
|
||||
BSD_ASSERT(_Thread_queue_Is_empty(&rw->reader_queue.Queue));
|
||||
|
||||
if (rtems_bsd_rwlock_wowned(rw)) {
|
||||
rw->nest_level = 0;
|
||||
rtems_bsd_rwlock_wunlock(rw);
|
||||
}
|
||||
|
||||
_Thread_queue_Destroy(&rw->writer_queue);
|
||||
_Thread_queue_Destroy(&rw->reader_queue);
|
||||
lock_destroy(lock);
|
||||
}
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif /* __cplusplus */
|
||||
|
||||
#endif /* _RTEMS_BSD_MACHINE_RTEMS_BSD_RWLOCKIMPL_H_ */
|
||||
Reference in New Issue
Block a user