/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup POSIXAPI
*
* @brief Locking and Unlocking a Mutex
*/
/*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/posix/muteximpl.h>
#include <rtems/posix/posixapi.h>
#include <string.h>
bool _POSIX_Mutex_Auto_initialization( POSIX_Mutex_Control *the_mutex )
{
unsigned long zero;
unsigned long flags;
/* We cannot use memset() and memcmp() due to structure internal padding */
zero = 0;
zero |= the_mutex->flags;
#if defined(RTEMS_SMP)
zero |= _Atomic_Load_uint(
&the_mutex->Recursive.Mutex.Queue.Queue.Lock.next_ticket,
ATOMIC_ORDER_RELAXED
);
zero |= _Atomic_Load_uint(
&the_mutex->Recursive.Mutex.Queue.Queue.Lock.now_serving,
ATOMIC_ORDER_RELAXED
);
#else
zero |= the_mutex->Recursive.Mutex.Queue.reserved[ 0 ];
zero |= the_mutex->Recursive.Mutex.Queue.reserved[ 1 ];
#endif
zero |= (unsigned long) the_mutex->Recursive.Mutex.Queue.Queue.heads;
zero |= (unsigned long) the_mutex->Recursive.Mutex.Queue.Queue.owner;
zero |= (unsigned long) the_mutex->Recursive.Mutex.Queue.Queue.name;
zero |= the_mutex->Recursive.nest_level;
zero |= (unsigned long) the_mutex->Priority_ceiling.Node.RBTree.Node.rbe_left;
zero |= (unsigned long) the_mutex->Priority_ceiling.Node.RBTree.Node.rbe_right;
zero |= (unsigned long) the_mutex->Priority_ceiling.Node.RBTree.Node.rbe_parent;
zero |= (unsigned long) the_mutex->Priority_ceiling.Node.RBTree.Node.rbe_color;
zero |= (unsigned long) the_mutex->Priority_ceiling.priority;
zero |= (unsigned long) (the_mutex->Priority_ceiling.priority >> 32);
zero |= (unsigned long) the_mutex->scheduler;
if ( zero != 0 ) {
return false;
}
flags = (uintptr_t) the_mutex ^ POSIX_MUTEX_MAGIC;
flags &= ~POSIX_MUTEX_FLAGS_MASK;
the_mutex->flags = flags;
return true;
}
/*
* 11.3.3 Locking and Unlocking a Mutex, P1003.1c/Draft 10, p. 93
*
* NOTE: P1003.4b/D8 adds pthread_mutex_timedlock(), p. 29
*/
int pthread_mutex_unlock(
pthread_mutex_t *mutex
)
{
POSIX_Mutex_Control *the_mutex;
unsigned long flags;
Thread_queue_Context queue_context;
Thread_Control *executing;
Status_Control status;
the_mutex = _POSIX_Mutex_Get( mutex );
POSIX_MUTEX_VALIDATE_OBJECT( the_mutex, flags );
executing = _POSIX_Mutex_Acquire( the_mutex, &queue_context );
switch ( _POSIX_Mutex_Get_protocol( flags ) ) {
case POSIX_MUTEX_PRIORITY_CEILING:
status = _POSIX_Mutex_Ceiling_surrender(
the_mutex,
executing,
&queue_context
);
break;
case POSIX_MUTEX_NO_PROTOCOL:
status = _POSIX_Mutex_Surrender(
the_mutex,
POSIX_MUTEX_NO_PROTOCOL_TQ_OPERATIONS,
executing,
&queue_context
);
break;
default:
_Assert(
_POSIX_Mutex_Get_protocol( flags ) == POSIX_MUTEX_PRIORITY_INHERIT
);
status = _POSIX_Mutex_Surrender(
the_mutex,
POSIX_MUTEX_PRIORITY_INHERIT_TQ_OPERATIONS,
executing,
&queue_context
);
break;
}
return _POSIX_Get_error( status );
}