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 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, sig can be used to request  asynchronous  notification  when  all
       operations have completed.  If sig is NULL, no notification is sent.

       For SIGEV_KEVENT notifications, the posted kevent will contain:

       Member    Value
       ident     list
       filter    EVFILT_LIO
       udata     value stored in sig->sigev_value

       For  SIGEV_SIGNO  and  SIGEV_THREAD_ID  notifications, the information for the queued signal will include
       SI_ASYNCIO in the si_code field and the value stored in sig->sigev_value in the si_value field.

       For  SIGEV_THREAD  notifications,   the   value   stored   in   sig->sigev_value   is   passed   to   the
       sig->sigev_notify_function as described in sigevent(3).

       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 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.

       [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}.

       [EINVAL]           The asynchronous notification method in sig->sigev_notify is invalid or not supported.

       [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), sigevent(3), siginfo(3), aio(4)

STANDARDS

       The lio_listio() function is expected to conform to IEEE Std 1003.1-2001 (“POSIX.1”).

HISTORY

       The lio_listio() system call first appeared in FreeBSD 3.0.

Debian                                             Dec 7, 2019                                     LIO_LISTIO(2)