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/*
* $Id$
*/
#include <stdarg.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <limits.h>
#include <rtems/system.h>
#include <rtems/score/object.h>
#include <rtems/posix/semaphore.h>
#include <rtems/posix/time.h>
#include <rtems/posix/seterr.h>
/*PAGE
*
* 11.2.3 Initialize/Open a Named Semaphore, P1003.1b-1993, p.221
*
* NOTE: When oflag is O_CREAT, then optional third and fourth
* parameters must be present.
*/
sem_t *sem_open(
const char *name,
int oflag,
...
/* mode_t mode, */
/* unsigned int value */
)
{
va_list arg;
mode_t mode;
unsigned int value = 0;
int status;
Objects_Id the_semaphore_id;
POSIX_Semaphore_Control *the_semaphore;
Objects_Locations location;
if ( oflag & O_CREAT ) {
va_start(arg, oflag);
/*mode = (mode_t) va_arg( arg, mode_t * );*/
mode = va_arg( arg, mode_t );
/*value = (unsigned int) va_arg( arg, unsigned int * );*/
value = va_arg( arg, unsigned int );
va_end(arg);
}
status = _POSIX_Semaphore_Name_to_id( name, &the_semaphore_id );
/*
* If the name to id translation worked, then the semaphore exists
* and we can just return a pointer to the id. Otherwise we may
* need to check to see if this is a "semaphore does not exist"
* or some other miscellaneous error on the name.
*/
if ( status ) {
if ( status == EINVAL ) { /* name -> ID translation failed */
if ( !(oflag & O_CREAT) ) { /* willing to create it? */
set_errno_and_return_minus_one_cast( ENOENT, sem_t * );
}
/* we are willing to create it */
}
/* some type of error */
/*set_errno_and_return_minus_one_cast( status, sem_t * );*/
} else { /* name -> ID translation succeeded */
if ( (oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL) ) {
set_errno_and_return_minus_one_cast( EEXIST, sem_t * );
}
/*
* XXX In this case we need to do an ID->pointer conversion to
* check the mode. This is probably a good place for a subroutine.
*/
the_semaphore = _POSIX_Semaphore_Get( &the_semaphore_id, &location );
the_semaphore->open_count += 1;
return (sem_t *)&the_semaphore->Object.id;
}
/* XXX verify this comment...
*
* At this point, the semaphore does not exist and everything has been
* checked. We should go ahead and create a semaphore.
*/
status = _POSIX_Semaphore_Create_support(
name,
FALSE, /* not shared across processes */
value,
&the_semaphore
);
if ( status == -1 )
return (sem_t *) -1;
return (sem_t *) &the_semaphore->Object.id;
}
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