lio_listio(3) — Linux manual page


LIO_LISTIO(3)             Linux Programmer's Manual            LIO_LISTIO(3)

NAME         top

       lio_listio - initiate a list of I/O requests

SYNOPSIS         top

       #include <aio.h>

       int lio_listio(int mode, struct aiocb *const aiocb_list[],
                      int nitems, struct sigevent *sevp);

       Link with -lrt.

DESCRIPTION         top

       The lio_listio() function initiates the list of I/O operations
       described by the array aiocb_list.

       The mode operation has one of the following values:

              The call blocks until all operations are complete.  The sevp
              argument is ignored.

              The I/O operations are queued for processing and the call
              returns immediately.  When all of the I/O operations complete,
              asynchronous notification occurs, as specified by the sevp
              argument; see sigevent(7) for details.  If sevp is NULL, no
              asynchronous notification occurs.

       The aiocb_list argument is an array of pointers to aiocb structures
       that describe I/O operations.  These operations are executed in an
       unspecified order.  The nitems argument specifies the size of the
       array aiocb_list.  null pointers in aiocb_list are ignored.

       In each control block in aiocb_list, the aio_lio_opcode field
       specifies the I/O operation to be initiated, as follows:

              Initiate a read operation.  The operation is queued as for a
              call to aio_read(3) specifying this control block.

              Initiate a write operation.  The operation is queued as for a
              call to aio_write(3) specifying this control block.

              Ignore this control block.

       The remaining fields in each control block have the same meanings as
       for aio_read(3) and aio_write(3).  The aio_sigevent fields of each
       control block can be used to specify notifications for the individual
       I/O operations (see sigevent(7)).

RETURN VALUE         top

       If mode is LIO_NOWAIT, lio_listio() returns 0 if all I/O operations
       are successfully queued.  Otherwise, -1 is returned, and errno is set
       to indicate the error.

       If mode is LIO_WAIT, lio_listio() returns 0 when all of the I/O
       operations have completed successfully.  Otherwise, -1 is returned,
       and errno is set to indicate the error.

       The return status from lio_listio() provides information only about
       the call itself, not about the individual I/O operations.  One or
       more of the I/O operations may fail, but this does not prevent other
       operations completing.  The status of individual I/O operations in
       aiocb_list can be determined using aio_error(3).  When an operation
       has completed, its return status can be obtained using aio_return(3).
       Individual I/O operations can fail for the reasons described in
       aio_read(3) and aio_write(3).

ERRORS         top

       The lio_listio() function may fail for the following reasons:

       EAGAIN Out of resources.

       EAGAIN The number of I/O operations specified by nitems would cause
              the limit AIO_MAX to be exceeded.

       EINTR  mode was LIO_WAIT and a signal was caught before all I/O
              operations completed; see signal(7).  (This may even be one of
              the signals used for asynchronous I/O completion

       EINVAL mode is invalid, or nitems exceeds the limit AIO_LISTIO_MAX.

       EIO    One of more of the operations specified by aiocb_list failed.
              The application can check the status of each operation using

       If lio_listio() fails with the error EAGAIN, EINTR, or EIO, then some
       of the operations in aiocb_list may have been initiated.  If
       lio_listio() fails for any other reason, then none of the I/O
       operations has been initiated.

VERSIONS         top

       The lio_listio() function is available since glibc 2.1.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface    Attribute     Value   │
       │lio_listio() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008.

NOTES         top

       It is a good idea to zero out the control blocks before use.  The
       control blocks must not be changed while the I/O operations are in
       progress.  The buffer areas being read into or written from must not
       be accessed during the operations or undefined results may occur.
       The memory areas involved must remain valid.

       Simultaneous I/O operations specifying the same aiocb structure
       produce undefined results.

SEE ALSO         top

       aio_cancel(3), aio_error(3), aio_fsync(3), aio_return(3),
       aio_suspend(3), aio_write(3), aio(7)

COLOPHON         top

       This page is part of release 5.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

                                 2020-04-11                    LIO_LISTIO(3)

Pages that refer to this page: aio_cancel(3)aio_error(3)aio_fsync(3)aio_read(3)aio_return(3)aio_suspend(3)aio_write(3)gai_cancel(3)gai_error(3)gai_suspend(3)getaddrinfo_a(3)aio(7)sigevent(7)