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authorJoel Sherrill <joel.sherrill@OARcorp.com>1999-11-02 18:00:15 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>1999-11-02 18:00:15 +0000
commit799c767d319d65c94b3770e82490c8dd4dc80378 (patch)
treebf9909c7f3ae617a34e401a0f88dc314f982f772 /cpukit/posix/src/semopen.c
parentSplit some more stuff out of psignal.c. (diff)
downloadrtems-799c767d319d65c94b3770e82490c8dd4dc80378.tar.bz2
Split the POSIX semaphore manager into multiple files.
Diffstat (limited to 'cpukit/posix/src/semopen.c')
-rw-r--r--cpukit/posix/src/semopen.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/cpukit/posix/src/semopen.c b/cpukit/posix/src/semopen.c
new file mode 100644
index 0000000000..c0ac7ffe3b
--- /dev/null
+++ b/cpukit/posix/src/semopen.c
@@ -0,0 +1,109 @@
+/*
+ * $Id$
+ */
+
+#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;
+
+}