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, 33 insertions, 4 deletions

diff --git a/cpukit/posix/include/rtems/posix/time.h b/cpukit/posix/include/rtems/posix/time.h
index 8f4d4b6257..0782996399 100644
--- a/cpukit/posix/include/rtems/posix/time.h
+++ b/cpukit/posix/include/rtems/posix/time.h
@@ -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
@@ -18,10 +18,39 @@
 
 #include <rtems/score/timespec.h>
 
-/*
- *  _POSIX_Absolute_timeout_to_ticks
+/** @brief Absolute Timeout Conversion Results
+ *
+ *  This enumeration defines the possible results of converting
+ *  an absolute time used for timeouts to POSIX blocking calls to
+ *  a number of ticks.
+ */
+typedef enum {
+  /** The timeout is invalid. */
+  POSIX_ABSOLUTE_TIMEOUT_INVALID,
+  /** The timeout represents a time that is in the past. */
+  POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST,
+  /** The timeout represents a time that is equal to the current time. */
+  POSIX_ABSOLUTE_TIMEOUT_IS_NOW,
+  /** The timeout represents a time that is in the future. */
+  POSIX_ABSOLUTE_TIMEOUT_IS_IN_FUTURE,
+} POSIX_Absolute_timeout_conversion_results_t;
+
+/**
+ *  @brief Convert Absolute Timeout to Ticks
+ *
+ *  This method takes an absolute time being used as a timeout
+ *  to a blocking directive, validates it and returns the number
+ *  of corresponding clock ticks for use by the SuperCore.
+ *
+ *  @param[in] abstime is the timeout
+ *  @param[in] ticks_out will contain the number of ticks
+ *
+ *  @return This method returns the number of ticks in @a ticks_out
+ *          and a status value indicating whether the absolute time
+ *          is valid, in the past, equal to the current time or in 
+ *          the future as it should be.
  */
-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
 );