Merge pull request #514 from lf-lang/fix-wait-until

Perform busy waiting when the wait duration is less than `MIN_SLEEP_DURATION`

Author: erlingrj

core/threaded/reactor_threaded.c

@@ -199,9 +199,8 @@ bool wait_until(instant_t wait_until_time, lf_cond_t* condition) {
     LF_PRINT_DEBUG("-------- Waiting until physical time " PRINTF_TIME, wait_until_time - start_time);
     // Check whether we actually need to wait, or if we have already passed the timepoint.
     interval_t wait_duration = wait_until_time - lf_time_physical();
-    if (wait_duration < MIN_SLEEP_DURATION) {
-      LF_PRINT_DEBUG("Wait time " PRINTF_TIME " is less than MIN_SLEEP_DURATION " PRINTF_TIME ". Skipping wait.",
-                     wait_duration, MIN_SLEEP_DURATION);
+    if (wait_duration < 0) {
+      LF_PRINT_DEBUG("We have already passed " PRINTF_TIME ". Skipping wait.", wait_until_time);
       return true;
     }
 

include/core/threaded/reactor_threaded.h

@@ -93,8 +93,8 @@ void lf_synchronize_with_other_federates(void);
  * if that event time matches or exceeds the specified time.
  *
  * The mutex lock associated with the condition argument is assumed to be held by
- * the calling thread. This mutex is released while waiting. If the wait time is
- * too small to actually wait (less than MIN_SLEEP_DURATION), then this function
+ * the calling thread. This mutex is released while waiting. If the current physical
+ * time has already passed the specified time, then this function
  * immediately returns true and the mutex is not released.
  *
  * @param env Environment within which we are executing.