diff options
Diffstat (limited to 'cpukit/posix/src/mqueueopen.c')
| -rw-r--r-- | cpukit/posix/src/mqueueopen.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/cpukit/posix/src/mqueueopen.c b/cpukit/posix/src/mqueueopen.c new file mode 100644 index 0000000000..2b96236fb5 --- /dev/null +++ b/cpukit/posix/src/mqueueopen.c @@ -0,0 +1,155 @@ +/* + * NOTE: The structure of the routines is identical to that of POSIX + * Message_queues to leave the option of having unnamed message + * queues at a future date. They are currently not part of the + * POSIX standard but unnamed message_queues are. This is also + * the reason for the apparently unnecessary tracking of + * the process_shared attribute. [In addition to the fact that + * it would be trivial to add pshared to the mq_attr structure + * and have process private message queues.] + * + * This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open + * time. + * + * COPYRIGHT (c) 1989-2009. + * 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.com/license/LICENSE. + * + * $Id$ + */ + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +#include <stdarg.h> + +#include <pthread.h> +#include <limits.h> +#include <errno.h> +#include <fcntl.h> +#include <mqueue.h> + +#include <rtems/system.h> +#include <rtems/score/watchdog.h> +#include <rtems/seterr.h> +#include <rtems/posix/mqueue.h> +#include <rtems/posix/time.h> + +/* + * 15.2.2 Open a Message Queue, P1003.1b-1993, p. 272 + */ +mqd_t mq_open( + const char *name, + int oflag, + ... + /* mode_t mode, */ + /* struct mq_attr attr */ +) +{ + va_list arg; + mode_t mode; + struct mq_attr *attr = NULL; + int status; + Objects_Id the_mq_id; + POSIX_Message_queue_Control *the_mq; + POSIX_Message_queue_Control_fd *the_mq_fd; + Objects_Locations location; + + _Thread_Disable_dispatch(); + + if ( oflag & O_CREAT ) { + va_start(arg, oflag); + mode = (mode_t) va_arg( arg, unsigned int ); + attr = (struct mq_attr *) va_arg( arg, struct mq_attr * ); + va_end(arg); + } + + the_mq_fd = _POSIX_Message_queue_Allocate_fd(); + if ( !the_mq_fd ) { + _Thread_Enable_dispatch(); + rtems_set_errno_and_return_minus_one( ENFILE ); + } + the_mq_fd->oflag = oflag; + + status = _POSIX_Message_queue_Name_to_id( name, &the_mq_id ); + + /* + * If the name to id translation worked, then the message queue exists + * and we can just return a pointer to the id. Otherwise we may + * need to check to see if this is a "message queue does not exist" + * or some other miscellaneous error on the name. + */ + if ( status ) { + /* + * Unless provided a valid name that did not already exist + * and we are willing to create then it is an error. + */ + if ( !( status == ENOENT && (oflag & O_CREAT) ) ) { + _POSIX_Message_queue_Free_fd( the_mq_fd ); + _Thread_Enable_dispatch(); + rtems_set_errno_and_return_minus_one_cast( status, mqd_t ); + } + + } else { /* name -> ID translation succeeded */ + /* + * Check for existence with creation. + */ + if ( (oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL) ) { + _POSIX_Message_queue_Free_fd( the_mq_fd ); + _Thread_Enable_dispatch(); + rtems_set_errno_and_return_minus_one_cast( EEXIST, mqd_t ); + } + + /* + * In this case we need to do an ID->pointer conversion to + * check the mode. + */ + the_mq = _POSIX_Message_queue_Get( the_mq_id, &location ); + the_mq->open_count += 1; + the_mq_fd->Queue = the_mq; + _Objects_Open_string( + &_POSIX_Message_queue_Information_fds, + &the_mq_fd->Object, + NULL + ); + _Thread_Enable_dispatch(); + _Thread_Enable_dispatch(); + return (mqd_t)the_mq_fd->Object.id; + + } + + /* + * At this point, the message queue does not exist and everything has been + * checked. We should go ahead and create a message queue. + */ + status = _POSIX_Message_queue_Create_support( + name, + true, /* shared across processes */ + attr, + &the_mq + ); + + /* + * errno was set by Create_support, so don't set it again. + */ + if ( status == -1 ) { + _POSIX_Message_queue_Free_fd( the_mq_fd ); + _Thread_Enable_dispatch(); + return (mqd_t) -1; + } + + the_mq_fd->Queue = the_mq; + _Objects_Open_string( + &_POSIX_Message_queue_Information_fds, + &the_mq_fd->Object, + NULL + ); + + _Thread_Enable_dispatch(); + + return (mqd_t) the_mq_fd->Object.id; +} |