NAME

       io_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 specified 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 TO

       io_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_context_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 genenerating the error EINVAL.

SEE ALSO

       io_cancel(2), io_destroy(2), io_setup(2), io_submit(2), aio(7), time(7)

COLOPHON

       This page is part of release 3.54 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/.