Implement agreed-upon semantics for delay/timeout arguments.

A delay/timeout <=0.0 results in a yield/poll.
A delay/timeout >0.0 is rounded up to 1 tick.

src/libCom/osi/os/RTEMS/osdEvent.c

@@ -125,14 +125,22 @@ epicsEventWaitWithTimeout(epicsEventId id, double timeOut)
 {
     rtems_id sid = (rtems_id)id;
     rtems_status_code sc;
+    rtems_unsigned32 wait;
     rtems_interval delay;
     extern double rtemsTicksPerSecond_double;
     
     SEMSTAT(1)
-    delay = timeOut * rtemsTicksPerSecond_double;
-    if (delay == 0)
-        delay = 1;
-    sc = rtems_semaphore_obtain (sid, RTEMS_WAIT, delay);
+    if (timeOut <= 0.0) {
+        wait = RTEMS_NO_WAIT;
+        delay = 0;
+    }
+    else {
+        wait = RTEMS_WAIT;
+        delay = timeOut * rtemsTicksPerSecond_double;
+        if (delay == 0)
+            delay++;
+    }
+    sc = rtems_semaphore_obtain (sid, wait, delay);
     if (sc == RTEMS_SUCCESSFUL)
         return epicsEventWaitOK;
     else if (sc == RTEMS_TIMEOUT)

src/libCom/osi/os/RTEMS/osdMutex.c

@@ -153,19 +153,27 @@ epicsMutexLockStatus epicsMutexLockWithTimeout(
 #ifdef RTEMS_FAST_MUTEX
     Semaphore_Control *the_semaphore = (Semaphore_Control *)id;
     ISR_Level level;
+    boolean wait;
     rtems_interval delay;
     extern double rtemsTicksPerSecond_double;
 
     SEMSTAT(1)
-    delay = timeOut * rtemsTicksPerSecond_double;
-    if (delay == 0)
-        delay = 1;
+    if (timeOut <= 0.0) {
+        wait = FALSE;
+        delay = 0;
+    }
+    else {
+        wait = TRUE;
+        delay = timeOut * rtemsTicksPerSecond_double;
+        if (delay == 0)
+            delay++;
+    }
     _ISR_Disable( level );
     _CORE_mutex_Seize(
         &the_semaphore->Core_control.mutex,
         the_semaphore->Object.id,
-        1,   /* TRUE or FALSE */
-        delay, /* same as passed to obtain -- ticks */
+        wait,
+        delay,
         level
     );
     if (_Thread_Executing->Wait.return_code == 0)

src/libCom/osi/os/RTEMS/osdThread.c

@@ -371,9 +371,14 @@ epicsThreadSleep (double seconds)
     rtems_interval delay;
     extern double rtemsTicksPerSecond_double;
     
-    delay = seconds * rtemsTicksPerSecond_double;
-    if (delay == 0)
-        delay++;
+    if (seconds <= 0.0) {
+        delay = 0;
+    }
+    else {
+        delay = seconds * rtemsTicksPerSecond_double;
+        if (delay == 0)
+            delay++;
+    }
     sc = rtems_task_wake_after (delay);
     if(sc != RTEMS_SUCCESSFUL)
         errlogPrintf("epicsThreadSleep: %s\n", rtems_status_text (sc));