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From Neil Conway <...@cs.berkeley.edu>
Subject Re: Questions about apr_poll
Date Wed, 06 Jan 2010 23:07:01 GMT
Another minor point on a related subject: the documentation for
pollcb_create() states that the size parameter controls "The maximum
number of descriptors that a single _poll can return." This isn't true
for the poll(2) pollcb method, however: _add() returns APR_ENOMEM if
the number of active descriptors exceeds the initial size.


On Tue, Jan 5, 2010 at 12:16 AM, Neil Conway <nrc@cs.berkeley.edu> wrote:
> (1) The documentation for apr_pollset_create() states that the "size"
> parameter controls "The maximum number of descriptors that this
> pollset can hold." However, ancient history like
> http://www.mail-archive.com/dev@apr.apache.org/msg12876.html suggests
> that "size" now just controls the # of events that can be signalled by
> a single call to apr_pollset_poll().
> From glancing at the code, it seems that the select provider has a
> fixed limit on the pollset size, but kqueue, epoll and event port do
> not, for example. Is that accurate? Perhaps the apr_pollset
> documentation can be updated accordingly.
> (2) Is there a reason why apr_pollset_wakeup() was added, but there's
> no analogous apr_pollcb_wakeup()?
> Speaking of which, it might be good to document the high-level
> differences between apr_pollset and apr_pollcb -- without doing some
> digging, it is not at all clear how they differ, or why one might
> prefer one over the other.
> Thanks in advance for any advice,
> Neil

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