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-rw-r--r--cpukit/posix/src/mutextimedlock.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/cpukit/posix/src/mutextimedlock.c b/cpukit/posix/src/mutextimedlock.c
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+++ b/cpukit/posix/src/mutextimedlock.c
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+/*
+ * Mutex Timed Lock
+ */
+
+/*
+ * COPYRIGHT (c) 1989-2008.
+ * 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 <errno.h>
+#include <pthread.h>
+
+#include <rtems/system.h>
+#include <rtems/score/coremutex.h>
+#include <rtems/score/watchdog.h>
+#if defined(RTEMS_MULTIPROCESSING)
+#include <rtems/score/mpci.h>
+#endif
+#include <rtems/posix/mutex.h>
+#include <rtems/posix/priority.h>
+#include <rtems/posix/time.h>
+
+/*PAGE
+ *
+ * 11.3.3 Locking and Unlocking a Mutex, P1003.1c/Draft 10, p. 93
+ *
+ * NOTE: P1003.4b/D8 adds pthread_mutex_timedlock(), p. 29
+ */
+
+int pthread_mutex_timedlock(
+ pthread_mutex_t *mutex,
+ const struct timespec *abstime
+)
+{
+ Watchdog_Interval ticks;
+ bool do_wait = true;
+ POSIX_Absolute_timeout_conversion_results_t status;
+ int lock_status;
+
+ /*
+ * POSIX requires that blocking calls with timeouts that take
+ * an absolute timeout must ignore issues with the absolute
+ * time provided if the operation would otherwise succeed.
+ * So we check the abstime provided, and hold on to whether it
+ * is valid or not. If it isn't correct and in the future,
+ * then we do a polling operation and convert the UNSATISFIED
+ * status into the appropriate error.
+ *
+ * If the status is POSIX_ABSOLUTE_TIMEOUT_INVALID,
+ * POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST, or POSIX_ABSOLUTE_TIMEOUT_IS_NOW,
+ * then we should not wait.
+ */
+ status = _POSIX_Absolute_timeout_to_ticks( abstime, &ticks );
+ if ( status != POSIX_ABSOLUTE_TIMEOUT_IS_IN_FUTURE )
+ do_wait = false;
+
+ lock_status = _POSIX_Mutex_Lock_support( mutex, do_wait, ticks );
+ /*
+ * This service only gives us the option to block. We used a polling
+ * attempt to lock if the abstime was not in the future. If we did
+ * not obtain the mutex, then not look at the status immediately,
+ * make sure the right reason is returned.
+ */
+ if ( !do_wait && (lock_status == EBUSY) ) {
+ if ( status == POSIX_ABSOLUTE_TIMEOUT_INVALID )
+ return EINVAL;
+ if ( status == POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST ||
+ status == POSIX_ABSOLUTE_TIMEOUT_IS_NOW )
+ return ETIMEDOUT;
+ }
+
+ return lock_status;
+}