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/* io_getevents.c
libaio Linux async I/O interface
Copyright 2002 Red Hat, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "libaio.h"
#include <errno.h>
#include <stdlib.h>
#include <time.h>
#include "syscall.h"
io_syscall5(int, __io_getevents_0_4, io_getevents, io_context_t, ctx, long, min_nr, long, nr, struct io_event *, events, struct timespec *, timeout)
#define AIO_RING_MAGIC 0xa10a10a1
/* Ben will hate me for this */
struct aio_ring {
unsigned id; /* kernel internal index number */
unsigned nr; /* number of io_events */
unsigned head;
unsigned tail;
unsigned magic;
unsigned compat_features;
unsigned incompat_features;
unsigned header_length; /* size of aio_ring */
};
int io_getevents(io_context_t ctx, long min_nr, long nr, struct io_event * events, struct timespec * timeout)
{
struct aio_ring *ring;
ring = (struct aio_ring*)ctx;
if (ring==NULL || ring->magic != AIO_RING_MAGIC)
goto do_syscall;
if (timeout!=NULL && timeout->tv_sec == 0 && timeout->tv_nsec == 0) {
if (ring->head == ring->tail)
return 0;
}
do_syscall:
return __io_getevents_0_4(ctx, min_nr, nr, events, timeout);
}
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