* Events are still delivered after an IO object is deleted from epoll
@ 2015-12-07 3:40 Daniele Orlandi
0 siblings, 0 replies; 2+ messages in thread
From: Daniele Orlandi @ 2015-12-07 3:40 UTC (permalink / raw)
To: sleepy-penguin
Hello,
I have a classic event loop like this:
loop do
@actor_epoll.wait do |events, io|
receive(events, io)
end
end
In #receive, sometimes I close and remove an "io" object from the epoll
via #del (e.g. in a timerfd I close ad remove a socket)
However it appears that if there are queued events the block may still
be called afterwise.
Not a big deal, easily workaround-able, but you may want to give a look
at it.
Bye,
--
Daniele Orlandi
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Events are still delivered after an IO object is deleted from epoll
[not found] <5664FAC6.8040705@orlandi.com>
@ 2015-12-07 4:13 ` Eric Wong
0 siblings, 0 replies; 2+ messages in thread
From: Eric Wong @ 2015-12-07 4:13 UTC (permalink / raw)
To: Daniele Orlandi; +Cc: sleepy-penguin
Daniele Orlandi <daniele@orlandi.com> wrote:
> In #receive, sometimes I close and remove an "io" object from the epoll
> via #del (e.g. in a timerfd I close ad remove a socket)
>
> However it appears that if there are queued events the block may still
> be called afterwise.
>
> Not a big deal, easily workaround-able, but you may want to give a look
> at it.
That's because the default maxevents for wait; so the underlying
epoll_wait syscall is still retrieving 64 events at once into the Ruby
process.
Try passing 1 as the maxevents argument:
@actor_epoll.wait(1) do |events, io|
receive(events, io)
end
Retrieving more events into the kernel at once improves throughput
performance and benefits typical single-threaded event loops.
However, my typical usage is actually maxevents=1; but I'm a weirdo who
abuses epoll as a thread queue :)
Anyways, I've been thinking about revamping the API a bit;
so maybe this could return an array instead.
Thanks for the feedback!
^ permalink raw reply [flat|nested] 2+ messages in thread
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2015-12-07 3:40 Events are still delivered after an IO object is deleted from epoll Daniele Orlandi
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2015-12-07 4:13 ` Eric Wong
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