Delay zero after successful action.

diff --git a/Lib/sched.py b/Lib/sched.py
index b70a998ab70e11cefe95b0c5fada3a5a96cfa1f8..6abd2512227edff858cd790583a697d19cdf21ec 100644 (file)
--- a/Lib/sched.py
+++ b/Lib/sched.py
@@ -11,8 +11,8 @@
 # and millisleep from the built-in module time, or you can implement
 # simulated time by writing your own functions.  This can also be
 # used to integrate scheduling with STDWIN events; the delay function
-# is allowed to modify the queue.  Time can be expressed
-# as integers or floating point numbers, as long as it is consistent.
+# is allowed to modify the queue.  Time can be expressed as
+# integers or floating point numbers, as long as it is consistent.
 
 # Events are specified by tuples (time, priority, action, argument).
 # As in UNIX, lower priority numbers mean higher priority; in this
@@ -83,6 +83,11 @@ class scheduler():
        # exceptions are not caught but the scheduler's state
        # remains well-defined so run() may be called again.
        #
+       # A questionably hack is added to allow other threads to run:
+       # just after an event is executed, a delay of 0 is executed,
+       # to avoid monopolizing the CPU when other threads are also
+       # runnable.
+       #
        def run(self):
                q = self.queue
                while q:
@@ -93,4 +98,5 @@ class scheduler():
                        else:
                                del q[0]
                                void = action(argument)
+                               self.delayfunc(0) # Let other threads run
        #