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       io_getevents - read asynchronous I/O events from the completion queue


       #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.


       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, and is specified  as
       a relative timeout in a structure of the following form:

           struct timespec {
               time_t tv_sec;      /* seconds */
               long   tv_nsec;     /* nanoseconds [0 .. 999999999] */

       The  specified  time  will be rounded up to the system clock granularity and is guaranteed
       not to expire  early.

       Specifying timeout as NULL means block indefinitely until at least min_nr events have been


       On  success,  io_getevents() returns the number of events read.  This may be 0, or a value
       less than min_nr, if the timeout expired.  It may  also  be  a  nonzero  value  less  than
       min_nr, if the call was interrupted by a signal handler.

       For the failure return, see NOTES.


       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.


       The asynchronous I/O system calls first appeared in Linux 2.5.


       io_getevents()  is  Linux-specific and should not be used in programs that are intended to
       be portable.


       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.


       An invalid ctx_id may cause a segmentation fault instead of generating the error EINVAL.


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


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