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/*
* Linux AIO request queue
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "ioq.h"
void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs)
{
int rc;
ioq->fd = fd;
ioq->max_reqs = max_reqs;
memset(&ioq->io_ctx, 0, sizeof ioq->io_ctx);
rc = io_setup(max_reqs, &ioq->io_ctx);
if (rc != 0) {
fprintf(stderr, "ioq io_setup failed %d\n", rc);
exit(1);
}
rc = event_notifier_init(&ioq->io_notifier, 0);
if (rc != 0) {
fprintf(stderr, "ioq io event notifier creation failed %d\n", rc);
exit(1);
}
ioq->freelist = g_malloc0(sizeof ioq->freelist[0] * max_reqs);
ioq->freelist_idx = 0;
ioq->queue = g_malloc0(sizeof ioq->queue[0] * max_reqs);
ioq->queue_idx = 0;
}
void ioq_cleanup(IOQueue *ioq)
{
g_free(ioq->freelist);
g_free(ioq->queue);
event_notifier_cleanup(&ioq->io_notifier);
io_destroy(ioq->io_ctx);
}
EventNotifier *ioq_get_notifier(IOQueue *ioq)
{
return &ioq->io_notifier;
}
struct iocb *ioq_get_iocb(IOQueue *ioq)
{
/* Underflow cannot happen since ioq is sized for max_reqs */
assert(ioq->freelist_idx != 0);
struct iocb *iocb = ioq->freelist[--ioq->freelist_idx];
ioq->queue[ioq->queue_idx++] = iocb;
return iocb;
}
void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb)
{
/* Overflow cannot happen since ioq is sized for max_reqs */
assert(ioq->freelist_idx != ioq->max_reqs);
ioq->freelist[ioq->freelist_idx++] = iocb;
}
struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
unsigned int count, long long offset)
{
struct iocb *iocb = ioq_get_iocb(ioq);
if (read) {
io_prep_preadv(iocb, ioq->fd, iov, count, offset);
} else {
io_prep_pwritev(iocb, ioq->fd, iov, count, offset);
}
io_set_eventfd(iocb, event_notifier_get_fd(&ioq->io_notifier));
return iocb;
}
int ioq_submit(IOQueue *ioq)
{
int rc = io_submit(ioq->io_ctx, ioq->queue_idx, ioq->queue);
ioq->queue_idx = 0; /* reset */
return rc;
}
int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
void *opaque)
{
struct io_event events[ioq->max_reqs];
int nevents, i;
do {
nevents = io_getevents(ioq->io_ctx, 0, ioq->max_reqs, events, NULL);
} while (nevents < 0 && errno == EINTR);
if (nevents < 0) {
return nevents;
}
for (i = 0; i < nevents; i++) {
ssize_t ret = ((uint64_t)events[i].res2 << 32) | events[i].res;
completion(events[i].obj, ret, opaque);
ioq_put_iocb(ioq, events[i].obj);
}
return nevents;
}
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