LIO_LISTIO
Section: Linux Programmer's Manual (3)
Updated: 2021-03-22
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NAME
lio_listio - initiate a list of I/O requests
SYNOPSIS
#include <aio.h>
int lio_listio(int mode, struct aiocb *restrict const aiocb_list[restrict],
int nitems, struct sigevent *restrict sevp);
Link with -lrt.
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:
- 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 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:
- 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
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:
- 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 notification.)
- 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
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
The
lio_listio()
function is available since glibc 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
Interface | Attribute | Value
|
lio_listio()
| Thread safety | MT-Safe
|
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)
COLOPHON
This page is part of release 5.11 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
https://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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Time: 06:22:44 GMT, May 09, 2021