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Date: Wed, 20 Oct 2004 16:04:27 -0400
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Thread-Topic: aio_connect ?
Thread-Index: AcS23mDylHHulLbjStybFNXDu4AmLAAAZkQw
From: "Christopher M. Sedore" <cmsedore@maxwell.syr.edu>
To: "Igor Sysoev" <is@rambler-co.ru>,
	"Ronald F. Guilmette" <rfg@monkeys.com>
cc: freebsd-net@freebsd.org
Subject: RE: aio_connect ?
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=20

> From: owner-freebsd-net@freebsd.org=20
> [mailto:owner-freebsd-net@freebsd.org] On Behalf Of Igor Sysoev
> Subject: Re: aio_connect ?
>=20

[...]

> While the developing my server nginx, I found the POSIX aio_*=20
> operations
> uncomfortable. I do not mean a different programming style, I mean
> the aio_read() and aio_write() drawbacks - they have no scatter-gather
> capabilities (aio_readv/aio_writev) and they require too many=20
> syscalls.
> E.g, the reading requires
> *) 3 syscalls for ready data: aio_read(), aio_error(), aio_return()
> *) 5 syscalls for non-ready data: aio_read(), aio_error(),
>    waiting for notification, then aio_error(), aio_return(),
>    or if timeout occuired - aio_cancel(), aio_error().
>=20

This is why I added aio_waitcomplete().  It reduces both cases to two
syscalls.

-Chris=20