NAME
lio_listio —
list directed I/O (REALTIME)
LIBRARY
library “librt”
SYNOPSIS
#include
<aio.h>
int
lio_listio(int mode,
struct aiocb * const list[], int
nent, struct sigevent *sig);
DESCRIPTION
Thelio_listio()
function initiates a list of I/O requests with a single function call. The
list argument is an array of pointers to
aiocb structures describing each operation to perform,
with nent elements. NULL
elements are ignored.
The aio_lio_opcode field of each aiocb specifies the operation to be performed. The following operations are supported:
LIO_READ- Read data as if by a call to aio_read(3).
LIO_NOP- No operation.
LIO_WRITE- Write data as if by a call to aio_write(3).
If the mode argument is
LIO_WAIT,
lio_listio()
does not return until all the requested operations have been completed. If
mode is LIO_NOWAIT, the
requests are processed asynchronously, and the signal specified by
sig is sent when all operations have completed. If
sig is NULL, the calling
process is not notified of I/O completion.
The order in which the requests are carried out is not specified, and there is no guarantee that they will be executed sequentially.
RETURN VALUES
If mode is LIO_WAIT,
the lio_listio() function returns 0 if the
operations completed successfully, otherwise -1.
If mode is
LIO_NOWAIT, the lio_listio()
function returns 0 if the operations are successfully queued, otherwise
-1.
ERRORS
The lio_listio() function will fail
if:
- [
EAGAIN] - There are not enough resources to enqueue the requests; or the request
would cause the system-wide limit
AIO_MAXto be exceeded. - [
EINTR] - A signal interrupted the system call before it could be completed.
- [
EINVAL] - The mode argument is neither
LIO_WAITnorLIO_NOWAIT, or nent is greater thanAIO_LISTIO_MAX. - [
EIO] - One or more requests failed.
In addition, the lio_listio() function may
fail for any of the reasons listed for
aio_read(3) and
aio_write(3).
If lio_listio() succeeds, or fails with an
error code of EAGAIN, EINTR,
or EIO, some of the requests may have been
initiated. The caller should check the error status of each
aiocb structure individually by calling
aio_error(3).
SEE ALSO
STANDARDS
The lio_listio() function is expected to
conform to IEEE Std 1003.1-2001
(“POSIX.1”).