summaryrefslogtreecommitdiffstats
path: root/c/src/exec/score/src/coremutexseize.c
diff options
context:
space:
mode:
Diffstat (limited to 'c/src/exec/score/src/coremutexseize.c')
-rw-r--r--c/src/exec/score/src/coremutexseize.c156
1 files changed, 156 insertions, 0 deletions
diff --git a/c/src/exec/score/src/coremutexseize.c b/c/src/exec/score/src/coremutexseize.c
new file mode 100644
index 0000000000..a2c8a37d71
--- /dev/null
+++ b/c/src/exec/score/src/coremutexseize.c
@@ -0,0 +1,156 @@
+/*
+ * Mutex Handler
+ *
+ * DESCRIPTION:
+ *
+ * This package is the implementation of the Mutex Handler.
+ * This handler provides synchronization and mutual exclusion capabilities.
+ *
+ * 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/score/isr.h>
+#include <rtems/score/coremutex.h>
+#include <rtems/score/states.h>
+#include <rtems/score/thread.h>
+#include <rtems/score/threadq.h>
+
+/*PAGE
+ *
+ * _CORE_mutex_Seize
+ *
+ * This routine attempts to allocate a mutex to the calling thread.
+ *
+ * Input parameters:
+ * the_mutex - pointer to mutex control block
+ * id - id of object to wait on
+ * wait - TRUE if wait is allowed, FALSE otherwise
+ * timeout - number of ticks to wait (0 means forever)
+ *
+ * Output parameters: NONE
+ *
+ * INTERRUPT LATENCY:
+ * available
+ * wait
+ */
+
+void _CORE_mutex_Seize(
+ CORE_mutex_Control *the_mutex,
+ Objects_Id id,
+ boolean wait,
+ Watchdog_Interval timeout
+)
+{
+ Thread_Control *executing;
+ ISR_Level level;
+
+ executing = _Thread_Executing;
+ switch ( the_mutex->Attributes.discipline ) {
+ case CORE_MUTEX_DISCIPLINES_FIFO:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
+ break;
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
+ if ( executing->current_priority <
+ the_mutex->Attributes.priority_ceiling) {
+ executing->Wait.return_code = CORE_MUTEX_STATUS_CEILING_VIOLATED;
+ return;
+ }
+ }
+ executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL;
+ _ISR_Disable( level );
+ if ( ! _CORE_mutex_Is_locked( the_mutex ) ) {
+ the_mutex->lock = CORE_MUTEX_LOCKED;
+ the_mutex->holder = executing;
+ the_mutex->holder_id = executing->Object.id;
+ the_mutex->nest_count = 1;
+ executing->resource_count++;
+ _ISR_Enable( level );
+ switch ( the_mutex->Attributes.discipline ) {
+ case CORE_MUTEX_DISCIPLINES_FIFO:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
+ /* already the highest priority */
+ break;
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
+ if ( the_mutex->Attributes.priority_ceiling <
+ executing->current_priority ) {
+ _Thread_Change_priority(
+ the_mutex->holder,
+ the_mutex->Attributes.priority_ceiling,
+ FALSE
+ );
+ }
+ }
+ return;
+ }
+
+ if ( _Objects_Are_ids_equal(
+ _Thread_Executing->Object.id, the_mutex->holder_id ) ) {
+ if ( _CORE_mutex_Is_nesting_allowed( &the_mutex->Attributes ) )
+ the_mutex->nest_count++;
+ else
+ executing->Wait.return_code = CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED;
+
+ _ISR_Enable( level );
+ return;
+ }
+
+ if ( !wait ) {
+ _ISR_Enable( level );
+ executing->Wait.return_code = CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT;
+ return;
+ }
+
+ _Thread_queue_Enter_critical_section( &the_mutex->Wait_queue );
+ executing->Wait.queue = &the_mutex->Wait_queue;
+ executing->Wait.id = id;
+ _ISR_Enable( level );
+
+ switch ( the_mutex->Attributes.discipline ) {
+ case CORE_MUTEX_DISCIPLINES_FIFO:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
+ break;
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
+ if ( the_mutex->holder->current_priority > executing->current_priority ) {
+ _Thread_Change_priority(
+ the_mutex->holder,
+ executing->current_priority,
+ FALSE
+ );
+ }
+ break;
+ }
+
+ _Thread_queue_Enqueue( &the_mutex->Wait_queue, timeout );
+
+ if ( _Thread_Executing->Wait.return_code == CORE_MUTEX_STATUS_SUCCESSFUL ) {
+ switch ( the_mutex->Attributes.discipline ) {
+ case CORE_MUTEX_DISCIPLINES_FIFO:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY:
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
+ break;
+ case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
+ if ( the_mutex->Attributes.priority_ceiling <
+ executing->current_priority ) {
+ _Thread_Change_priority(
+ executing,
+ the_mutex->Attributes.priority_ceiling,
+ FALSE
+ );
+ };
+ break;
+ }
+ }
+}
+