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+/*
+ * Semaphore Manager
+ *
+ * DESCRIPTION:
+ *
+ * This package is the implementation of the Semaphore Manager.
+ * This manager utilizes standard Dijkstra counting semaphores to provide
+ * synchronization and mutual exclusion capabilities.
+ *
+ * Directives provided are:
+ *
+ * + create a semaphore
+ * + get an ID of a semaphore
+ * + delete a semaphore
+ * + acquire a semaphore
+ * + release a semaphore
+ *
+ * COPYRIGHT (c) 1989-1998.
+ * On-Line Applications Research Corporation (OAR).
+ * Copyright assigned to U.S. Government, 1994.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.OARcorp.com/rtems/license.html.
+ *
+ * $Id$
+ */
+
+#include <rtems/system.h>
+#include <rtems/rtems/status.h>
+#include <rtems/rtems/support.h>
+#include <rtems/rtems/attr.h>
+#include <rtems/score/isr.h>
+#include <rtems/score/object.h>
+#include <rtems/rtems/options.h>
+#include <rtems/rtems/sem.h>
+#include <rtems/score/coremutex.h>
+#include <rtems/score/coresem.h>
+#include <rtems/score/states.h>
+#include <rtems/score/thread.h>
+#include <rtems/score/threadq.h>
+#if defined(RTEMS_MULTIPROCESSING)
+#include <rtems/score/mpci.h>
+#endif
+#include <rtems/score/sysstate.h>
+
+#include <rtems/score/interr.h>
+
+/*PAGE
+ *
+ * rtems_semaphore_obtain
+ *
+ * This directive allows a thread to acquire a semaphore.
+ *
+ * Input parameters:
+ * id - semaphore id
+ * option_set - wait option
+ * timeout - number of ticks to wait (0 means wait forever)
+ *
+ * Output parameters:
+ * RTEMS_SUCCESSFUL - if successful
+ * error code - if unsuccessful
+ */
+
+rtems_status_code rtems_semaphore_obtain(
+ Objects_Id id,
+ unsigned32 option_set,
+ rtems_interval timeout
+)
+{
+ register Semaphore_Control *the_semaphore;
+ Objects_Locations location;
+ boolean wait;
+
+ the_semaphore = _Semaphore_Get( id, &location );
+ switch ( location ) {
+ case OBJECTS_REMOTE:
+#if defined(RTEMS_MULTIPROCESSING)
+ return _Semaphore_MP_Send_request_packet(
+ SEMAPHORE_MP_OBTAIN_REQUEST,
+ id,
+ option_set,
+ timeout
+ );
+#endif
+
+ case OBJECTS_ERROR:
+ return RTEMS_INVALID_ID;
+
+ case OBJECTS_LOCAL:
+ if ( _Options_Is_no_wait( option_set ) )
+ wait = FALSE;
+ else
+ wait = TRUE;
+
+ if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) {
+ _CORE_mutex_Seize(
+ &the_semaphore->Core_control.mutex,
+ id,
+ wait,
+ timeout
+ );
+ _Thread_Enable_dispatch();
+ return _Semaphore_Translate_core_mutex_return_code(
+ _Thread_Executing->Wait.return_code );
+ } else {
+ _CORE_semaphore_Seize(
+ &the_semaphore->Core_control.semaphore,
+ id,
+ wait,
+ timeout
+ );
+ _Thread_Enable_dispatch();
+ return _Semaphore_Translate_core_semaphore_return_code(
+ _Thread_Executing->Wait.return_code );
+ }
+ }
+
+ return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */
+}