2008-07-18 Joel Sherrill <joel.sherrill@oarcorp.com>

	PR 1291/cpukit
	* itron/inline/rtems/itron/semaphore.inl, itron/src/twai_sem.c,
	posix/include/mqueue.h, posix/include/rtems/posix/mqueue.h,
	posix/include/rtems/posix/semaphore.h,
	posix/include/rtems/posix/time.h, posix/src/condtimedwait.c,
	posix/src/mqueuereceive.c, posix/src/mqueuerecvsupp.c,
	posix/src/mqueuesend.c, posix/src/mqueuesendsupp.c,
	posix/src/mqueuetimedreceive.c, posix/src/mqueuetimedsend.c,
	posix/src/mutextimedlock.c, posix/src/mutextranslatereturncode.c,
	posix/src/posixtimespecabsolutetimeout.c,
	posix/src/prwlocktimedrdlock.c, posix/src/prwlocktimedwrlock.c,
	posix/src/semaphoretranslatereturncode.c,
	posix/src/semaphorewaitsupp.c, posix/src/semtimedwait.c,
	posix/src/semtrywait.c, posix/src/semwait.c,
	posix/src/sigtimedwait.c, posix/src/timersettime.c,
	posix/src/ualarm.c, rtems/src/semobtain.c,
	rtems/src/semtranslatereturncode.c,
	score/include/rtems/score/coremutex.h,
	score/include/rtems/score/coresem.h, score/src/coresemseize.c: This
	patch addresses issues on implementation of the timeout on the
	following POSIX services. Some of these services incorrectly took a
	timeout as a relative time. Others would compute a 0 delta to timeout
	if the absolute time and the current time were equal and thus
	incorrectly block the caller forever. The root of the confusion is
	that POSIX specifies that if the timeout is incorrect (e.g. in the
	past, is now, or is numerically invalid), that it does not matter if
	the call would succeed without blocking. This is in contrast to RTEMS
	programming style where all errors are checked before any critical
	sections are entered. This fix implemented a more uniform way of
	handling POSIX absolute time timeouts.
	    + pthread_cond_timedwait - could block forever
	    + mq_timedreceive - used relative not absolute time
	    + mq_timedsend - used relative not absolute time
	    + pthread_mutex_timedlock - used relative not absolute time
	    + pthread_rwlock_timedrdlock- used relative not absolute time
	    + pthread_rwlock_timedwrlock- used relative not absolute time
	    + sem_timedwait - could block forever

1 files changed, 34 insertions, 8 deletions

diff --git a/cpukit/posix/src/posixtimespecabsolutetimeout.c b/cpukit/posix/src/posixtimespecabsolutetimeout.c
index 52208e380b..036fd9ee8b 100644
--- a/cpukit/posix/src/posixtimespecabsolutetimeout.c
+++ b/cpukit/posix/src/posixtimespecabsolutetimeout.c
@@ -3,7 +3,7 @@
  */
 
 /*
- *  COPYRIGHT (c) 1989-2007.
+ *  COPYRIGHT (c) 1989-2008.
  *  On-Line Applications Research Corporation (OAR).
  *
  *  The license and distribution terms for this file may be
@@ -34,7 +34,7 @@
 /*
  *  The abstime is a walltime.  We turn it into an interval.
  */
-int _POSIX_Absolute_timeout_to_ticks(
+POSIX_Absolute_timeout_conversion_results_t _POSIX_Absolute_timeout_to_ticks(
   const struct timespec *abstime,
   Watchdog_Interval     *ticks_out
 )
@@ -42,21 +42,47 @@ int _POSIX_Absolute_timeout_to_ticks(
   struct timespec current_time;
   struct timespec difference;
 
-  if ( !_Timespec_Is_valid(abstime) )
-    return EINVAL;
+  
+  /*
+   *  Make sure there is always a value returned.
+   */
+  *ticks_out = 0;
 
-  _TOD_Get( &current_time );
+  /*
+   *  Is the absolute time even valid?
+   */
+  if ( !_Timespec_Is_valid(abstime) )
+    return POSIX_ABSOLUTE_TIMEOUT_INVALID;
 
   /*
-   *  Make sure the abstime is in the future
+   *  Is the absolute time in the past?
    */
+  _TOD_Get( &current_time );
+
   if ( _Timespec_Less_than( abstime, &current_time ) )
-    return EINVAL;
+    return POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST;
 
+  /*
+   *  How long until the requested absolute time?
+   */
   _Timespec_Subtract( &current_time, abstime, &difference );
 
+  /*
+   *  Internally the SuperCore uses ticks, so convert to them.
+   */
   *ticks_out = _Timespec_To_ticks( &difference );
 
-  return 0;
+  /*
+   *  If the difference was 0, then the future is now.  It is so bright
+   *  we better wear shades.
+   */
+  if ( !*ticks_out )
+    return POSIX_ABSOLUTE_TIMEOUT_IS_NOW;
+
+  /*
+   *  This is the case we were expecting and it took this long to
+   *  get here.
+   */
+  return POSIX_ABSOLUTE_TIMEOUT_IS_IN_FUTURE;
 }