/**
* @file
*
* @ingroup rtems_bsd_machine
*
* @brief Implementation of a mutex with a simple priority inheritance
* protocol.
*/
/*
* Copyright (c) 2014, 2018 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.
*/
#ifndef _RTEMS_BSD_MACHINE_RTEMS_BSD_MUTEXIMPL_H_
#define _RTEMS_BSD_MACHINE_RTEMS_BSD_MUTEXIMPL_H_
#include <machine/rtems-bsd-mutex.h>
#include <machine/rtems-bsd-support.h>
#include <sys/types.h>
#include <sys/lock.h>
#include <sys/systm.h>
#include <inttypes.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/threadqimpl.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
#define RTEMS_BSD_MUTEX_TQ_OPERATIONS \
&_Thread_queue_Operations_priority_inherit
static inline void
rtems_bsd_mutex_init(struct lock_object *lock, rtems_bsd_mutex *m,
struct lock_class *class, const char *name, const char *type, int flags)
{
_Thread_queue_Initialize(&m->queue, name);
m->nest_level = 0;
lock_init(lock, class, name, type, flags);
}
void rtems_bsd_mutex_lock_more(struct lock_object *lock, rtems_bsd_mutex *m,
Thread_Control *owner, Thread_Control *executing,
Thread_queue_Context *queue_context);
#define rtems_bsd_mutex_isr_disable(isr_level, queue_context) \
do { \
_ISR_Local_disable(isr_level); \
_ISR_lock_ISR_disable_profile( \
&(queue_context)->Lock_context.Lock_context) \
} while (0)
static inline void
rtems_bsd_mutex_acquire_critical(rtems_bsd_mutex *m,
Thread_queue_Context *queue_context)
{
_Thread_queue_Queue_acquire_critical(&m->queue.Queue,
&m->queue.Lock_stats, &queue_context->Lock_context.Lock_context);
#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG)
m->queue.owner = _SMP_lock_Who_am_I();
#endif
}
static inline void
rtems_bsd_mutex_release(rtems_bsd_mutex *m, ISR_Level isr_level,
Thread_queue_Context *queue_context)
{
#if defined(RTEMS_SMP) && defined(RTEMS_DEBUG)
_Assert( _Thread_queue_Is_lock_owner( &m->queue ) );
m->queue.owner = SMP_LOCK_NO_OWNER;
#endif
_Thread_queue_Queue_release_critical(&m->queue.Queue,
&queue_context->Lock_context.Lock_context);
_ISR_Local_enable(isr_level);
}
static inline void
rtems_bsd_mutex_set_isr_level(Thread_queue_Context *queue_context,
ISR_Level isr_level)
{
_ISR_lock_Context_set_level(&queue_context->Lock_context.Lock_context,
isr_level);
}
static inline void
rtems_bsd_mutex_lock(struct lock_object *lock, rtems_bsd_mutex *m)
{
ISR_Level isr_level;
Thread_queue_Context queue_context;
Thread_Control *executing;
Thread_Control *owner;
_Thread_queue_Context_initialize(&queue_context);
rtems_bsd_mutex_isr_disable(isr_level, &queue_context);
executing = _Thread_Executing;
rtems_bsd_mutex_acquire_critical(m, &queue_context);
owner = m->queue.Queue.owner;
if (__predict_true(owner == NULL)) {
m->queue.Queue.owner = executing;
_Thread_Resource_count_increment(executing);
rtems_bsd_mutex_release(m, isr_level, &queue_context);
} else {
rtems_bsd_mutex_set_isr_level(&queue_context, isr_level);
rtems_bsd_mutex_lock_more(lock, m, owner, executing,
&queue_context);
}
}
static inline int
rtems_bsd_mutex_trylock(struct lock_object *lock, rtems_bsd_mutex *m)
{
int success;
ISR_Level isr_level;
Thread_queue_Context queue_context;
Thread_Control *executing;
Thread_Control *owner;
_Thread_queue_Context_initialize(&queue_context);
rtems_bsd_mutex_isr_disable(isr_level, &queue_context);
executing = _Thread_Executing;
rtems_bsd_mutex_acquire_critical(m, &queue_context);
owner = m->queue.Queue.owner;
if (owner == NULL) {
m->queue.Queue.owner = executing;
_Thread_Resource_count_increment(executing);
success = 1;
} else if (owner == executing) {
if ((lock->lo_flags & LO_RECURSABLE) == 0) {
rtems_bsd_mutex_release(m, isr_level, &queue_context);
panic("mutex trylock: %s: not LO_RECURSABLE\n",
m->queue.Queue.name);
}
++m->nest_level;
success = 1;
} else {
success = 0;
}
rtems_bsd_mutex_release(m, isr_level, &queue_context);
return (success);
}
static inline void
rtems_bsd_mutex_unlock(rtems_bsd_mutex *m)
{
ISR_Level isr_level;
Thread_queue_Context queue_context;
Thread_Control *owner;
Thread_Control *executing;
int nest_level;
_Thread_queue_Context_initialize(&queue_context);
rtems_bsd_mutex_isr_disable(isr_level, &queue_context);
rtems_bsd_mutex_acquire_critical(m, &queue_context);
nest_level = m->nest_level;
owner = m->queue.Queue.owner;
executing = _Thread_Executing;
if (__predict_false(owner != executing)) {
rtems_bsd_mutex_release(m, isr_level, &queue_context);
panic("mutex unlock: %s: owner 0x%08" PRIx32
" != executing 0x%08" PRIx32 "\n", m->queue.Queue.name,
owner != NULL ? owner->Object.id : 0,
executing->Object.id);
}
if (__predict_true(nest_level == 0)) {
Thread_queue_Heads *heads;
heads = m->queue.Queue.heads;
m->queue.Queue.owner = NULL;
_Thread_Resource_count_decrement(owner);
if (__predict_true(heads == NULL)) {
rtems_bsd_mutex_release(m, isr_level, &queue_context);
} else {
rtems_bsd_mutex_set_isr_level(&queue_context, isr_level);
_Thread_queue_Surrender(&m->queue.Queue, heads, owner,
&queue_context, RTEMS_BSD_MUTEX_TQ_OPERATIONS);
}
} else {
m->nest_level = nest_level - 1;
rtems_bsd_mutex_release(m, isr_level, &queue_context);
}
}
static inline Thread_Control *
rtems_bsd_mutex_owner(const rtems_bsd_mutex *m)
{
return (m->queue.Queue.owner);
}
static inline int
rtems_bsd_mutex_owned(const rtems_bsd_mutex *m)
{
return (rtems_bsd_mutex_owner(m) == _Thread_Get_executing());
}
static inline int
rtems_bsd_mutex_recursed(const rtems_bsd_mutex *m)
{
return (m->nest_level != 0);
}
static inline const char *
rtems_bsd_mutex_name(const rtems_bsd_mutex *m)
{
return (m->queue.Queue.name);
}
static inline void
rtems_bsd_mutex_destroy(struct lock_object *lock, rtems_bsd_mutex *m)
{
BSD_ASSERT(m->queue.Queue.heads == NULL);
if (rtems_bsd_mutex_owned(m)) {
m->nest_level = 0;
rtems_bsd_mutex_unlock(m);
}
_Thread_queue_Destroy(&m->queue);
lock_destroy(lock);
}
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _RTEMS_BSD_MACHINE_RTEMS_BSD_MUTEXIMPL_H_ */
