aio_error.3

xen 3.2.2 源码

.TH aio_error 3 2002-09-12 "Linux 2.4" Linux AIO"
.SH NAME
aio_error \- Getting the Status of AIO Operations
.SH SYNOPSYS
.nf
.B #include <errno.h>
.sp
.br 
.B #include <aio.h>
.sp
.br
.BI "int aio_error (const struct aiocb *aiocbp)"
.fi
.SH DESCRIPTION
The function
.IR aio_error
determines the error state of the request described by the
.IR "struct aiocb"
variable pointed to by 
.I aiocbp
. 

When the operation is performed truly asynchronously (as with
.IR "aio_read"
and 
.IR "aio_write"
and with 
.IR "lio_listio"
when the mode is 
.IR "LIO_NOWAIT"
), one sometimes needs to know whether a
specific request already terminated and if so, what the result was.
When the sources are compiled with 
.IR "_FILE_OFFSET_BITS == 64"
this function is in fact 
.IR "aio_error64"
since the LFS interface transparently replaces the normal implementation.
.SH "RETURN VALUES"
If the request has not yet terminated the value returned is always
.IR "EINPROGRESS"
.  Once the request has terminated the value
.IR "aio_error"
returns is either 
.I 0
if the request completed successfully or it returns the value which would be stored in the
.IR "errno"
variable if the request would have been done using
.IR "read"
, 
.IR "write"
, or 
.IR "fsync"
.
.SH ERRORS
.TP
.IR "ENOSYS"
if it is not implemented.  It
could also return 
.TP
.IR "EINVAL"
if the 
.I aiocbp
parameter does not
refer to an asynchronous operation whose return status is not yet known.
.SH "SEE ALSO"
.BR aio(3),
.BR aio_cancel(3),
.BR aio_cancel64(3),
.BR aio_error64(3),
.BR aio_fsync(3),
.BR aio_fsync64(3),
.BR aio_init(3),
.BR aio_read(3),
.BR aio_read64(3),
.BR aio_return(3),
.BR aio_return64(3),
.BR aio_suspend(3),
.BR aio_suspend64(3),
.BR aio_write(3),
.BR aio_write64(3),
.BR errno(3),