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authorJoel Sherrill <joel.sherrill@OARcorp.com>1999-11-02 17:00:35 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>1999-11-02 17:00:35 +0000
commit4dc89814e10296b8f7212e949a97730abc9032e4 (patch)
tree1dad373c2e98f6b3127adfd48c7165ab248fbe55 /cpukit/posix/src/mqueueopen.c
parentMinor changes to make the screen match a bit better. (diff)
downloadrtems-4dc89814e10296b8f7212e949a97730abc9032e4.tar.bz2
Split mqueue.c into a variety of files.
Diffstat (limited to 'cpukit/posix/src/mqueueopen.c')
-rw-r--r--cpukit/posix/src/mqueueopen.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/cpukit/posix/src/mqueueopen.c b/cpukit/posix/src/mqueueopen.c
new file mode 100644
index 0000000000..4ea5a63b78
--- /dev/null
+++ b/cpukit/posix/src/mqueueopen.c
@@ -0,0 +1,116 @@
+/*
+ * 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.
+ *
+ * $Id$
+ */
+
+#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/posix/seterr.h>
+#include <rtems/posix/mqueue.h>
+#include <rtems/posix/time.h>
+
+/*PAGE
+ *
+ * 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;
+ int status;
+ Objects_Id the_mq_id;
+ POSIX_Message_queue_Control *the_mq;
+
+ if ( oflag & O_CREAT ) {
+ va_start(arg, oflag);
+ mode = (mode_t) va_arg( arg, mode_t );
+ attr = (struct mq_attr *) va_arg( arg, struct mq_attr * );
+ va_end(arg);
+ }
+
+ 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 ) {
+
+ if ( status == EINVAL ) { /* name -> ID translation failed */
+ if ( !(oflag & O_CREAT) ) { /* willing to create it? */
+ set_errno_and_return_minus_one( ENOENT );
+ return (mqd_t) -1;
+ }
+ /* we are willing to create it */
+ }
+ set_errno_and_return_minus_one( status ); /* some type of error */
+ return (mqd_t) -1;
+
+ } else { /* name -> ID translation succeeded */
+
+ if ( (oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL) ) {
+ set_errno_and_return_minus_one( EEXIST );
+ return (mqd_t) -1;
+ }
+
+ /*
+ * 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_mq->open_count += 1;
+
+ return (mqd_t)&the_mq->Object.id;
+
+ }
+
+ /* XXX verify this comment...
+ *
+ * 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 */
+ oflag,
+ attr,
+ &the_mq
+ );
+
+ if ( status == -1 )
+ return (mqd_t) -1;
+
+ return (mqd_t) &the_mq->Object.id;
+}
+