/**
* @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);
}
