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lio_listio(2)

NAME

     lio_listio -- list directed I/O (REALTIME)

LIBRARY

     Standard C Library (libc, -lc)

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 struc-
     tures 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 per-
     formed.  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 par-
     ticular, 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 opera-
     tions 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.

     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 IEEE Std 1003.1-2001
     (``POSIX.1'').

FreeBSD 5.4		       January 12, 2003 		   FreeBSD 5.4

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