The join() method is all about waiting for all the tasks to be done. If you
don't care whether the tasks have actually finished, you can periodically poll
the unfinished task count:
stop = time() + timeout
while q.unfinished_tasks and time() < stop:
sleep(1)
This loop will exist either when the tasks are done or when the timeout period
has elapsed.
Raymond
> On Thursday, June 17, 2010 5:52 PM pacopyc wrote:
> Hi, I am trying to work with threads and I need your help. This is
> code:
>
> from threading import Thread
> from Queue import Queue
> import time
> import random
>
> def test_fun (k,q,t):
> time.sleep(t)
> print "hello world from thread " + str(q.get()) + " (sleep time =
> " + str(t) + " sec.)"
> q.task_done()
>
> queue = Queue()
> for i in range (1,10):
> queue.put(i)
> for j in range(queue.qsize()):
> num = random.randint(1,30)
> worker = Thread(target=test_fun, args=(j,queue,num))
> worker.setDaemon(True)
> worker.start()
> queue.join()
>
>
> Execution:
>
> hello world from thread 1 (sleep time = 5 sec.)
> hello world from thread 2 (sleep time = 5 sec.)
> hello world from thread 3 (sleep time = 6 sec.)
> hello world from thread 4 (sleep time = 8 sec.)
> hello world from thread 5 (sleep time = 10 sec.)
> hello world from thread 6 (sleep time = 13 sec.)
> hello world from thread 7 (sleep time = 18 sec.)
> hello world from thread 8 (sleep time = 19 sec.)
> hello world from thread 9 (sleep time = 20 sec.)
>
> Some questions for you:
>
> 1) Why order is always the same (thread 1, thread 2, thread 3 ....
> thread 9) and also seconds are always increasing? I do not understand.
> 2) I'd like to decide a max time for each thread. If max time = 7 sec.
> I want to print only threads with sleep time <= 7 sec. How can I do?
> Can you modify my code?
>
> Thank you very much
>> On Thursday, June 17, 2010 7:04 PM MRAB wrote:
>> pacopyc wrote:
>>
>> 1)
>>
>> First it puts the numbers 1..9 into 'queue', then it starts 9 threads,
>> giving each a number 'num'.
>>
>> Each thread waits for 'num' seconds ('t' in the thread).
>>
>> The thread with the lowest value of 'num' wakes first, gets the first
>> entry from 'queue' (the value 1), and therefore prints "thread 1".
>>
>> The thread with the second-lowest value of 'num' wakes next, gets the
>> second entry from 'queue' (the value 2), and therefore prints "thread
>> 2".
>>
>> And so on.
>>
>> 2)
>>
>> If a thread is given a value of 'num' of more than a maximum, that
>> thread should not print its output, but it should still get the entry
>> from the queue (assuming that you want it to still behave the same
>> otherwise).
>>> On Friday, June 18, 2010 5:45 PM pacopyc wrote:
>>> =3D
>>> .
>>>
>>> Ok, the problem is that I want fix a time max for each thread. For
>>> example run 10 threads (each can terminate its work in 10 sec. max
>>> fixed time) and wait them. If they finish its work in < 10 sec. (for
>>> example 2 sec.) very good ... go on immediately (do not wait
>>> unnecessary time), but if a thread use more than 10 sec. stop wait (I
>>> kill it) .... when all threads have finished their work or when they
>>> have used all their available time (10 sec.) the program must go on
>>> (do not wait).
>>>> On Friday, June 18, 2010 6:27 PM MRAB wrote:
>>>> pacopyc wrote:
>>>> [snip]
>>>>
>>>> it is not possible to kill a thread. If you want a thread to have a
>>>> maximum time, the thread must check occasionally how long it has been
>>>> running and terminate if necessary.
>>>>
>>>> Another programming language (Java) originally had the ability to kill
>>>> threads, but that was later deprecated because it caused problems due to
>>>> not knowing what the thread was doing when it was killed (it might have
>>>> been in the middle of updating something at the time, for example,
>>>> leaving the system in an inconsistent state).
>>>>> On Friday, June 18, 2010 6:58 PM pacopyc wrote:
>>>>> Ok, I understand. But is possible fix max wait time (for example 60
>>>>> sec.) in main thread and check queue for task done and at the same
>>>>> time the remaining time. When all task have done or wait time has
>>>>> expired main thread go on. Is it possible? Can you write code?
>>>>> Thank you very much.
>>>>>> On Friday, June 18, 2010 7:45 PM MRAB wrote:
>>>>>> pacopyc wrote:
>>>>>>
>>>>>> The documentation says that queue.join() cannot have a timeout, so you
>>>>>> might have to think of another way to achieve the same effect.
>>>>>>
>>>>>> You could, for example, have a results queue into which a thread puts
>>>>>> something to indicate when it has finished, and then use the .get method
>>>>>> on it in the main thread (the .get method can have a timeout).
>>>>>> Submitted via EggHeadCafe - Software Developer Portal of Choice
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>>>>>> http://www.eggheadcafe.com/tutorials/aspnet/7fbc7a01-5d30-4cd3-b373-51d4a0e1afa8/custom-favorites-web-site-with-mongodb-and-norm.aspx
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