Re: Is there a better way to implement this:
Paul Boddie wrote: > Michael Yanowitz wrote: >> >>I guess I am looking for something portable (both >> Windows and Linux) where I can abort a function after >> a certain time limit expires. > > Doing a search for "timeout function Python" on Google reveals a number > of approaches. > Using threads: > > * http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/473878 That doesn't abort the calculation, however -- it just moves on with a default value instead of the actual result if that is not available after the specified timespan. The calculation may go on forever eating up resources. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a better way to implement this:
Michael Yanowitz wrote: > >I guess I am looking for something portable (both > Windows and Linux) where I can abort a function after > a certain time limit expires. Doing a search for "timeout function Python" on Google reveals a number of approaches. Using signals: * http://nick.vargish.org/clues/python-tricks.html * http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/307871 Using threads: * http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/473878 Using processes: * http://lfw.org/python/delegate.html Paul -- http://mail.python.org/mailman/listinfo/python-list
RE: Is there a better way to implement this:
Thanks. I suppose I could have used time.sleep(seconds) here. I did it in 0.01 because in an earlier verion, I did something else between the sleeps. I guess I am looking for something portable (both Windows and Linux) where I can abort a function after a certain time limit expires. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Benjamin Niemann Sent: Monday, January 22, 2007 11:19 AM To: python-list@python.org Subject: Re: Is there a better way to implement this: Michael Yanowitz wrote: > Hello: > >I wrote the code below (much irrelevant code removed). > This doesn't quite work. What I wanted it to do was > a) Execute function ftimed, which takes a function and a timeout > in seconds. > b) This will also execute function abort() as a thread. > This function just runs for the specified > number of seconds and returns. > However, before it returns, throws an exception. > c) If test() is still running when abort() is > finished, ftimed() should catch the exception and > return. > > It is catching the exception, however it continues running the function. > Why does it continue and not return? The exception is raised in the thread that executes the abort() function. The exception does not get caught and terminates this thread. The other (main) thread is unaffected - exceptions are local to a thread and there is currently no (portable) way to raise an exception in another thread. > What am I missing, or is there a better way to > implement this (having ftimed() return when the > abort-timer time is exceeded? You may use the signal.alarm() function, if you are on a UNIXoid system and you have only a signle time-out at a time (e.g. not nested). > import time, thread, sys > > thread_finished = "MAX RUN TIME EXCEEDED!" > > def abort (seconds): > start_time = time.time() > while ((time.time() - start_time) < seconds): > time.sleep(0.01) any reason for not using time.sleep(seconds) here? I suppose I could have, but in earlier versions > print "script run time exceeded max_run_time of", seconds, "seconds." > raise thread_finished > return > > > def test(): > i = 0 > while (True): >time.sleep(1) >print "HELLO", i >i+=1 > > > def ftimed (func, seconds): > thread.start_new_thread (abort, (seconds,)) > > try: > func() > except thread_finished: > print "Timeout" > return > > ftimed (test, 30) > print "Script finished" -- Benjamin Niemann Email: pink at odahoda dot de WWW: http://pink.odahoda.de/ -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a better way to implement this:
Michael Yanowitz wrote: > Hello: > >I wrote the code below (much irrelevant code removed). > This doesn't quite work. What I wanted it to do was > a) Execute function ftimed, which takes a function and a timeout > in seconds. > b) This will also execute function abort() as a thread. > This function just runs for the specified > number of seconds and returns. > However, before it returns, throws an exception. > c) If test() is still running when abort() is > finished, ftimed() should catch the exception and > return. > > It is catching the exception, however it continues running the function. > Why does it continue and not return? The exception is raised in the thread that executes the abort() function. The exception does not get caught and terminates this thread. The other (main) thread is unaffected - exceptions are local to a thread and there is currently no (portable) way to raise an exception in another thread. > What am I missing, or is there a better way to > implement this (having ftimed() return when the > abort-timer time is exceeded? You may use the signal.alarm() function, if you are on a UNIXoid system and you have only a signle time-out at a time (e.g. not nested). > import time, thread, sys > > thread_finished = "MAX RUN TIME EXCEEDED!" > > def abort (seconds): > start_time = time.time() > while ((time.time() - start_time) < seconds): > time.sleep(0.01) any reason for not using time.sleep(seconds) here? > print "script run time exceeded max_run_time of", seconds, "seconds." > raise thread_finished > return > > > def test(): > i = 0 > while (True): >time.sleep(1) >print "HELLO", i >i+=1 > > > def ftimed (func, seconds): > thread.start_new_thread (abort, (seconds,)) > > try: > func() > except thread_finished: > print "Timeout" > return > > ftimed (test, 30) > print "Script finished" -- Benjamin Niemann Email: pink at odahoda dot de WWW: http://pink.odahoda.de/ -- http://mail.python.org/mailman/listinfo/python-list
Is there a better way to implement this:
Hello: I wrote the code below (much irrelevant code removed). This doesn't quite work. What I wanted it to do was a) Execute function ftimed, which takes a function and a timeout in seconds. b) This will also execute function abort() as a thread. This function just runs for the specified number of seconds and returns. However, before it returns, throws an exception. c) If test() is still running when abort() is finished, ftimed() should catch the exception and return. It is catching the exception, however it continues running the function. Why does it continue and not return? What am I missing, or is there a better way to implement this (having ftimed() return when the abort-timer time is exceeded? import time, thread, sys thread_finished = "MAX RUN TIME EXCEEDED!" def abort (seconds): start_time = time.time() while ((time.time() - start_time) < seconds): time.sleep(0.01) print "script run time exceeded max_run_time of", seconds, "seconds." raise thread_finished return def test(): i = 0 while (True): time.sleep(1) print "HELLO", i i+=1 def ftimed (func, seconds): thread.start_new_thread (abort, (seconds,)) try: func() except thread_finished: print "Timeout" return ftimed (test, 30) print "Script finished" It presently generates the following output: $ python ./testthread.py HELLO 0 HELLO 1 HELLO 2 HELLO 3 HELLO 4 HELLO 5 HELLO 6 HELLO 7 HELLO 8 HELLO 9 HELLO 10 HELLO 11 HELLO 12 HELLO 13 HELLO 14 HELLO 15 HELLO 16 HELLO 17 HELLO 18 HELLO 19 HELLO 20 HELLO 21 HELLO 22 HELLO 23 HELLO 24 HELLO 25 HELLO 26 HELLO 27 HELLO 28 HELLO 29 script run time exceeded max_run_time of 30 seconds. Unhandled exception in thread started by Traceback (most recent call last): File "./testthread.py", line 10, in abort raise thread_finished MAX RUN TIME EXCEEDED! HELLO 30 HELLO 31 HELLO 32 Thanks in advance: Michael Yanowitz -- http://mail.python.org/mailman/listinfo/python-list
