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.\" $FreeBSD: /repoman/r/ncvs/src/lib/libc/sys/aio_suspend.2,v 1.22 2004/12/23 23:45:25 keramida Exp $
.\"
.Dd May 17, 2010
.Dt AIO_SUSPEND 3
.Os
.Sh NAME
.Nm aio_suspend
.Nd suspend until asynchronous I/O operations or timeout complete (REALTIME)
.Sh LIBRARY
.Lb librt
.Sh SYNOPSIS
.In aio.h
.Ft int
.Fn aio_suspend "const struct aiocb * const list[]" "int nent" "const struct timespec * timeout"
.Sh DESCRIPTION
The
.Fn aio_suspend
system call suspends the calling process until at least one of the
specified asynchronous I/O requests have completed, a signal is
delivered, or the
.Fa struct timeout
(see
.Xr timespec 3 )
has passed.
.Pp
The
.Fa list
argument
is an array of
.Fa nent
pointers to asynchronous I/O requests.
Array members containing
.Dv NULL
pointers will be silently ignored.
.Pp
If
.Fa timeout
is not a
.Dv NULL
pointer, it specifies a maximum interval to suspend.
If
.Fa timeout
is a
.Dv NULL
pointer, the suspend blocks indefinitely.
To effect a poll, the
.Fa timeout
should point to a zero-value timespec structure.
.Sh RETURN VALUES
If one or more of the specified asynchronous I/O requests have
completed,
.Fn aio_suspend
returns 0.
Otherwise it returns \-1 and sets
.Va errno
to indicate the error, as enumerated below.
.Sh ERRORS
The
.Fn aio_suspend
system call will fail if:
.Bl -tag -width Er
.It Bq Er EAGAIN
The
.Fa timeout
expired before any I/O requests completed.
.It Bq Er EINTR
The suspend was interrupted by a signal.
.It Bq Er EINVAL
The
.Fa list
argument
contains more than
.Dv AIO_LISTIO_MAX
asynchronous I/O requests, or at least one of the requests is not
valid.
.El
.Sh SEE ALSO
.Xr aio 3 ,
.Xr timespec 3
.Sh STANDARDS
The
.Fn aio_suspend
system call
is expected to conform to the
.St -p1003.1-2001
standard.
.Sh HISTORY
The
.Fn aio_suspend
system call first appeared in
.Nx 5.0 .