LIO_LISTIO(2)

NAME
lio_listio - list directed I/O (REALTIME)

LIBRARY
libc

SYNOPSIS
#include <aio.h>
int
lio_listio(int mode, struct aiocb * const [] list, int nent, struct sigevent *sig);

DESCRIPTION
The lio_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(2).

LIO_NOP
    No operation.

LIO_WRITE
    Write data as if by a call to aio_write(2).

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; in particular, there is no guarantee that they will be executed in the order 0, 1, ..., nent-1.

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 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.

[EAGAIN]
    The request would cause the system-wide limit AIO_MAX to be exceeded.

[EINVAL]
    The mode argument is neither LIO_WAIT nor LIO_NOWAIT, or nent is greater than AIO_LISTIO_MAX.

[EINTR]
    A signal interrupted the system call before it could be completed.

[EIO]
    One or more requests failed.

In addition, the lio_listio() function may fail for any of the reasons listed for aio_read(2) and aio_write(2).

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(2).

SEE ALSO
aio_error(2), aio_read(2), aio_write(2), read(2), write(2), aio(4)

STANDARDS
The lio_listio() function is expected to conform to p1003.1-2001.