IO_GETEVENTS(2) Linux Programmer's Manual IO_GETEVENTS(2)NAMEio_getevents - read asynchronous I/O events from the completion queue
SYNOPSIS
#include <linux/aio_abi.h> /* Defines needed types */
#include <linux/time.h> /* Defines 'struct timespec' */
int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
struct io_event *events, struct timespec *timeout);
Note: There is no glibc wrapper for this system call; see NOTES.
DESCRIPTION
The io_getevents() system call attempts to read at least min_nr events
and up to nr events from the completion queue of the AIO context speci‐
fied by ctx_id. The timeout argument specifies the amount of time to
wait for events, where a NULL timeout waits until at least min_nr
events have been seen. Note that timeout is relative.
RETURN VALUE
On success, io_getevents() returns the number of events read: 0 if no
events are available, or less than min_nr if the timeout has elapsed.
For the failure return, see NOTES.
ERRORS
EFAULT Either events or timeout is an invalid pointer.
EINVAL ctx_id is invalid. min_nr is out of range or nr is out of
range.
EINTR Interrupted by a signal handler; see signal(7).
ENOSYS io_getevents() is not implemented on this architecture.
VERSIONS
The asynchronous I/O system calls first appeared in Linux 2.5.
CONFORMING TOio_getevents() is Linux-specific and should not be used in programs
that are intended to be portable.
NOTES
Glibc does not provide a wrapper function for this system call. You
could invoke it using syscall(2). But instead, you probably want to
use the io_getevents() wrapper function provided by libaio.
Note that the libaio wrapper function uses a different type (io_con‐
text_t) for the ctx_id argument. Note also that the libaio wrapper
does not follow the usual C library conventions for indicating errors:
on error it returns a negated error number (the negative of one of the
values listed in ERRORS). If the system call is invoked via
syscall(2), then the return value follows the usual conventions for
indicating an error: -1, with errno set to a (positive) value that
indicates the error.
BUGS
An invalid ctx_id may cause a segmentation fault instead of generating
the error EINVAL.
SEE ALSOio_cancel(2), io_destroy(2), io_setup(2), io_submit(2), aio(7), time(7)COLOPHON
This page is part of release 3.58 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/.
Linux 2013-04-08 IO_GETEVENTS(2)