Hi all,
there is a section "Sleeping / Idiom - Sleep function for general use:" on
the page http://www.stackless.com/wiki/Idioms
The unwanted full load on the CPU core running the scheduler could be
avoided for the cost of tiny (and perhaps negligible) latency:
############## Start
import stackless, time
sleepingTasklets = []
def Sleep(secondsToWait):
channel = stackless.channel()
endTime = time.time() + secondsToWait
sleepingTasklets.append((endTime, channel))
sleepingTasklets.sort()
# Block until we get sent an awakening notification.
channel.receive()
def ManageSleepingTasklets(maxLatency=0.005):
while 1:
if len(sleepingTasklets):
endTime = sleepingTasklets[0][0]
toWait = endTime - time.time()
if toWait <= 0:
channel = sleepingTasklets[0][1]
del sleepingTasklets[0]
# We have to send something, but it doesn't matter what as
it is not used.
channel.send(None)
continue
else:
toWait = min(toWait, maxLatency)
else:
toWait = maxLatency
time.sleep(toWait)
stackless.schedule()
stackless.tasklet(ManageSleepingTasklets)()
def TestSleep():
print "pre", time.time()
Sleep(5.0)
print "post", time.time()
stackless.tasklet(TestSleep)()
stackless.run()
############## End
Remarks:
* Tested with pypy-2.2.1 only
* With the code above the load on the CPU core is never coming above 1%
after the tasks are completed (100% in original version), and is about 1%
when waiting for the second task.
* The camel-case naming is preserved.
* Currently there is a typo in this section on the web-site, where example
is given the ':' is missing after 'TestSleep()'
best regards
--
Valery Khamenya
_______________________________________________
Stackless mailing list
[email protected]
http://www.stackless.com/mailman/listinfo/stackless
