En Tue, 22 Apr 2008 13:32:38 -0300, sophie_newbie <[EMAIL PROTECTED]> escribió: > On Apr 22, 4:41 pm, "D'Arcy J.M. Cain" <[EMAIL PROTECTED]> wrote: >> On Tue, 22 Apr 2008 07:10:07 -0700 (PDT) >> sophie_newbie<[EMAIL PROTECTED]> wrote: >> > import threading >> > class MyThread ( threading.Thread ): >> > def run ( self ): >> > myLongCommand()... >> >> > import time >> >> > t = MyThread() >> > t.start() >> >> > while t.isAlive(): >> > print "." >> > time.sleep(.5) >> >> > print "OK" >> >> > The thing is this doesn't print a dot every half second. It just >> > pauses for ages until the thread is finished and prints prints ".OK". >> > But if I take out the "time.sleep(.5)" line it will keep printing dots >> > really fast until the thread is finished. So it looks like its the >> > time.sleep(.5) bit that is messing this up somehow? >> >> We know that your main routine gives up the processor but without a >> full definition of MyThread how do we know that it ever does? I > > "myLongCommand()... " is a call to an function in R (the statistical > programming language) via Rpy (A python module that allows calls to > R). The call takes a couple of minutes to execute. I'm trying to build > a web front end to this R function and instead of the user looking at > a blank screen for 2-3 mins, I want to print dots to let them feel > like the program isn't hanging. > > What I am saying is that without the "time.sleep(.5)" line, the above > code will print dots on the screen continuously for 2-3 mins, filling > it up with a ridiculous ammount of dots. > > Whereas with the time.sleep line, instead of pausing for half a second > between dots, its seems to print, as you correctly pointed out: > > . > OK > > With a pause of 2-3 minutes between the . and the OK.
A possible explanation is that the RPy call does not release the GIL; once the main thread loses it due to sleep, it can never reacquire it again until the RPy call finishes. Try contacting the RPy author, or perhaps there is a specific mailing list for RPy questions. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
