DESCRIPTION

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 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:

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

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

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

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

The lio_listio() function is available since glibc 2.1.

CONFORMING TO

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

NOTES

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

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