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author | Thomas Wouters <thomas@python.org> | 2006-04-21 10:40:58 (GMT) |
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committer | Thomas Wouters <thomas@python.org> | 2006-04-21 10:40:58 (GMT) |
commit | 49fd7fa4431da299196d74087df4a04f99f9c46f (patch) | |
tree | 35ace5fe78d3d52c7a9ab356ab9f6dbf8d4b71f4 /Doc/lib/libqueue.tex | |
parent | 9ada3d6e29d5165dadacbe6be07bcd35cfbef59d (diff) | |
download | cpython-49fd7fa4431da299196d74087df4a04f99f9c46f.zip cpython-49fd7fa4431da299196d74087df4a04f99f9c46f.tar.gz cpython-49fd7fa4431da299196d74087df4a04f99f9c46f.tar.bz2 |
Merge p3yk branch with the trunk up to revision 45595. This breaks a fair
number of tests, all because of the codecs/_multibytecodecs issue described
here (it's not a Py3K issue, just something Py3K discovers):
http://mail.python.org/pipermail/python-dev/2006-April/064051.html
Hye-Shik Chang promised to look for a fix, so no need to fix it here. The
tests that are expected to break are:
test_codecencodings_cn
test_codecencodings_hk
test_codecencodings_jp
test_codecencodings_kr
test_codecencodings_tw
test_codecs
test_multibytecodec
This merge fixes an actual test failure (test_weakref) in this branch,
though, so I believe merging is the right thing to do anyway.
Diffstat (limited to 'Doc/lib/libqueue.tex')
-rw-r--r-- | Doc/lib/libqueue.tex | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/Doc/lib/libqueue.tex b/Doc/lib/libqueue.tex index f1d892a..95ad47f 100644 --- a/Doc/lib/libqueue.tex +++ b/Doc/lib/libqueue.tex @@ -1,3 +1,4 @@ + \section{\module{Queue} --- A synchronized queue class} @@ -94,3 +95,51 @@ immediately available, else raise the \exception{Empty} exception \begin{methoddesc}{get_nowait}{} Equivalent to \code{get(False)}. \end{methoddesc} + +Two methods are offered to support tracking whether enqueued tasks have +been fully processed by daemon consumer threads. + +\begin{methoddesc}{task_done}{} +Indicate that a formerly enqueued task is complete. Used by queue consumer +threads. For each \method{get()} used to fetch a task, a subsequent call to +\method{task_done()} tells the queue that the processing on the task is complete. + +If a \method{join()} is currently blocking, it will resume when all items +have been processed (meaning that a \method{task_done()} call was received +for every item that had been \method{put()} into the queue). + +Raises a \exception{ValueError} if called more times than there were items +placed in the queue. +\versionadded{2.5} +\end{methoddesc} + +\begin{methoddesc}{join}{} +Blocks until all items in the queue have been gotten and processed. + +The count of unfinished tasks goes up whenever an item is added to the +queue. The count goes down whenever a consumer thread calls \method{task_done()} +to indicate that the item was retrieved and all work on it is complete. +When the count of unfinished tasks drops to zero, join() unblocks. +\versionadded{2.5} +\end{methoddesc} + +Example of how to wait for enqueued tasks to be completed: + +\begin{verbatim} + def worker(): + while True: + item = q.get() + do_work(item) + q.task_done() + + q = Queue() + for i in range(num_worker_threads): + t = Thread(target=worker) + t.setDaemon(True) + t.start() + + for item in source(): + q.put(item) + + q.join() # block until all tasks are done +\end{verbatim} |