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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:

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

       LIO_NOWAIT  The I/O operations are queued for processing and the call returns
                   immediately.  When 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:

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

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

       LIO_NOP   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.

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

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

       EIO    One of more of the operations specified by aiocb_list failed.  The
              application can check the status of each operation using aio_return(3).

       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.

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 3.32 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can be found
       at http://www.kernel.org/doc/man-pages/.

                                      2010-10-20                        LIO_LISTIO(3)

HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface

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