On 21Oct2018 18:06, Nathaniel Smith <n...@pobox.com> wrote:
On Sun, Oct 21, 2018, 16:48 MRAB <pyt...@mrabarnett.plus.com> wrote:
On 2018-10-21 22:30, Antoine Pitrou wrote:
> Ah. This is the one statement that makes me favorable to this
> idea.
> When there is a single consumer, it's easy enough to send a sentinel.
> But when there are multiple consumers, suddenly you must send exactly
> the right number of sentinels (which means you also have to careful
> keep track of their number, which isn't always easy). There's some
> delicate code doing exactly that in concurrent.futures.
>
You don't need more than one sentinel. When a consumer sees the
sentinel, it just needs to put it back for the other consumers.
Yes, this is exactly what my own IterableQUeue does.
I'm not sure if this is an issue the way Queue is used in practice, but in
general you have to be careful with this kind of circular flow because if
your queue communicates backpressure (which it should) then circular flows
can deadlock.
Haven't come across this myself. A closeable queue doesn't seem circular
to me. The handling of the sentinel is internal to the IterableQueue, so
external users never see it.
Cheers,
Cameron Simpson <c...@cskk.id.au>
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