splice.2: EAGAIN can occur when called on nonblocking file descriptors

[thirdparty/man-pages.git] / man3 / aio_return.3

.\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl)
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.TH AIO_RETURN 3 2017-09-15  "" "Linux Programmer's Manual"
.SH NAME
aio_return \- get return status of asynchronous I/O operation
.SH SYNOPSIS
.B "#include <aio.h>"
.PP
.BI "ssize_t aio_return(struct aiocb *" aiocbp );
.PP
Link with \fI\-lrt\fP.
.SH DESCRIPTION
The
.BR aio_return ()
function returns the final return status for the asynchronous I/O request
with control block pointed to by
.IR aiocbp .
(See
.BR aio (7)
for a description of the
.I aiocb
structure.)
.PP
This function should be called only once for any given request, after
.BR aio_error (3)
returns something other than
.BR EINPROGRESS .
.SH RETURN VALUE
If the asynchronous I/O operation has completed, this function returns
the value that would have been returned in case of a synchronous
.BR read (2),
.BR write (2),
.BR fsync (2)
or
.BR fdatasync (2),
call.
On error, \-1 is returned, and \fIerrno\fP is set appropriately.
.PP
If the asynchronous I/O operation has not yet completed,
the return value and effect of
.BR aio_return ()
are undefined.
.SH ERRORS
.TP
.B EINVAL
.I aiocbp
does not point at a control block for an asynchronous I/O request
of which the return status has not been retrieved yet.
.TP
.B ENOSYS
.BR aio_return ()
is not implemented.
.SH VERSIONS
The
.BR aio_return ()
function is available since glibc 2.1.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR aio_return ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
.SH EXAMPLE
See
.BR aio (7).
.SH SEE ALSO
.BR aio_cancel (3),
.BR aio_error (3),
.BR aio_fsync (3),
.BR aio_read (3),
.BR aio_suspend (3),
.BR aio_write (3),
.BR lio_listio (3),
.BR aio (7)