diff options
Diffstat (limited to 'rtemsbsd/rtems/rtems-kernel-rwlockimpl.c')
| -rw-r--r-- | rtemsbsd/rtems/rtems-kernel-rwlockimpl.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c b/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c new file mode 100644 index 00000000..2434e51d --- /dev/null +++ b/rtemsbsd/rtems/rtems-kernel-rwlockimpl.c @@ -0,0 +1,177 @@ +/** + * @file + * + * @ingroup rtems_bsd_rtems + * + * @brief TODO. + */ + +/* + * Copyright (c) 2017 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * 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. + */ + +#include <machine/rtems-bsd-kernel-space.h> +#include <machine/rtems-bsd-rwlockimpl.h> + +#include <rtems/score/schedulerimpl.h> + +void +rtems_bsd_rwlock_wlock_more(const struct lock_object *lock, + rtems_bsd_rwlock *rw, Thread_Control *executing, + rtems_bsd_rwlock_context *context) +{ + Thread_Control *wowner; + + wowner = rtems_bsd_rwlock_wowner(rw); + + if (wowner == executing) { + BSD_ASSERT(lock->lo_flags & LO_RECURSABLE); + ++rw->nest_level; + + _Thread_queue_Release(&rw->writer_queue, &context->writer); + } else { + _Thread_queue_Context_set_thread_state(&context->writer, + STATES_WAITING_FOR_RWLOCK); + _Thread_queue_Context_set_enqueue_do_nothing_extra( + &context->writer); + _Thread_queue_Context_set_deadlock_callout(&context->writer, + _Thread_queue_Deadlock_fatal); + _Thread_queue_Enqueue(&rw->writer_queue.Queue, + &_Thread_queue_Operations_priority, executing, + &context->writer); + } +} + +static Thread_Control * +rtems_bsd_rwlock_flush_reader_filter(Thread_Control *reader, + Thread_queue_Queue *queue, Thread_queue_Context *queue_context) +{ + rtems_bsd_rwlock *rw; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + ++rw->readers; + _Thread_Resource_count_increment(reader); + return (reader); +} + +static void +rtems_bsd_rwlock_flush_reader_post_release(Thread_queue_Queue *queue, + Thread_queue_Context *queue_context) +{ + rtems_bsd_rwlock *rw; + rtems_bsd_rwlock_context *context; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, + reader); + _Thread_queue_Release(&rw->writer_queue, &context->writer); +} + +void +rtems_bsd_rwlock_wunlock_more(rtems_bsd_rwlock *rw, Thread_Control *wowner, + rtems_bsd_rwlock_context *context) +{ + + if (!_Thread_queue_Is_empty(&rw->reader_queue.Queue)) { + BSD_ASSERT(rw->readers == 0); + rtems_bsd_rwlock_ready_waiting_readers(rw, context); + } else { + BSD_ASSERT(!_Thread_queue_Is_empty(&rw->writer_queue.Queue)); + _Thread_queue_Surrender(&rw->writer_queue.Queue, + rw->writer_queue.Queue.heads, wowner, &context->writer, + &_Thread_queue_Operations_priority); + } +} + +static void +rtems_bsd_rwlock_reader_enqueue(Thread_queue_Queue *queue, + Thread_Control *executing, Per_CPU_Control *cpu_self, + Thread_queue_Context *queue_context +) +{ + rtems_bsd_rwlock *rw; + rtems_bsd_rwlock_context *context; + + rw = RTEMS_CONTAINER_OF(queue, rtems_bsd_rwlock, reader_queue.Queue); + context = RTEMS_CONTAINER_OF(queue_context, rtems_bsd_rwlock_context, + reader); + _Thread_queue_Release(&rw->writer_queue, &context->writer); +} + +void +rtems_bsd_rwlock_rlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + Thread_Control *executing; + + executing = _Thread_Executing; + + _Thread_queue_Context_initialize(&context->reader); + _Thread_queue_Context_set_thread_state(&context->reader, + STATES_WAITING_FOR_RWLOCK); + _Thread_queue_Context_set_enqueue_callout( + &context->reader, rtems_bsd_rwlock_reader_enqueue); + _Thread_queue_Context_set_deadlock_callout(&context->reader, + _Thread_queue_Deadlock_fatal); + _Thread_queue_Acquire(&rw->reader_queue, &context->reader); + _Thread_queue_Enqueue(&rw->reader_queue.Queue, + &_Thread_queue_Operations_FIFO, executing, &context->reader); +} + +void +rtems_bsd_rwlock_runlock_more(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + + if (!_Thread_queue_Is_empty(&rw->writer_queue.Queue)) { + BSD_ASSERT(rw->readers == 0); + + _Thread_queue_Surrender(&rw->writer_queue.Queue, + rw->writer_queue.Queue.heads, NULL, &context->writer, + &_Thread_queue_Operations_priority); + } else { + BSD_ASSERT(!_Thread_queue_Is_empty(&rw->reader_queue.Queue)); + rtems_bsd_rwlock_ready_waiting_readers(rw, context); + } +} + +void +rtems_bsd_rwlock_ready_waiting_readers(rtems_bsd_rwlock *rw, + rtems_bsd_rwlock_context *context) +{ + + _Thread_queue_Context_initialize(&context->reader); + _Thread_queue_Acquire(&rw->reader_queue, &context->reader); + _Thread_queue_Flush_critical(&rw->reader_queue.Queue, + &_Thread_queue_Operations_FIFO, + rtems_bsd_rwlock_flush_reader_filter, + rtems_bsd_rwlock_flush_reader_post_release, + &context->reader); +} |