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/**
* @file
*
* @brief Locking and Unlocking a Mutex
* @ingroup POSIXAPI
*/
/*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if 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 );
}
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