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/*
* Simple app that demonstrates how to setup an io_uring interface,
* submit and complete IO against it, and then tear it down.
*
* gcc -Wall -O2 -D_GNU_SOURCE -o io_uring-test io_uring-test.c -luring
*/
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "liburing.h"
#define QD 4
int main(int argc, char *argv[])
{
struct io_uring ring;
int i, fd, ret, pending, done;
struct io_uring_sqe *sqe;
struct io_uring_cqe *cqe;
struct iovec *iovecs;
off_t offset;
void *buf;
if (argc < 2) {
printf("%s: file\n", argv[0]);
return 1;
}
ret = io_uring_queue_init(QD, &ring, 0);
if (ret < 0) {
fprintf(stderr, "queue_init: %s\n", strerror(-ret));
return 1;
}
fd = open(argv[1], O_RDONLY | O_DIRECT);
if (fd < 0) {
perror("open");
return 1;
}
iovecs = calloc(QD, sizeof(struct iovec));
for (i = 0; i < QD; i++) {
if (posix_memalign(&buf, 4096, 4096))
return 1;
iovecs[i].iov_base = buf;
iovecs[i].iov_len = 4096;
}
offset = 0;
i = 0;
do {
sqe = io_uring_get_sqe(&ring);
if (!sqe)
break;
io_uring_prep_readv(sqe, fd, &iovecs[i], 1, offset);
offset += iovecs[i].iov_len;
i++;
} while (1);
ret = io_uring_submit(&ring);
if (ret < 0) {
fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret));
return 1;
}
done = 0;
pending = ret;
for (i = 0; i < pending; i++) {
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret < 0) {
fprintf(stderr, "io_uring_wait_cqe: %s\n", strerror(-ret));
return 1;
}
done++;
ret = 0;
if (cqe->res != 4096) {
fprintf(stderr, "ret=%d, wanted 4096\n", cqe->res);
ret = 1;
}
io_uring_cqe_seen(&ring, cqe);
if (ret)
break;
}
printf("Submitted=%d, completed=%d\n", pending, done);
close(fd);
io_uring_queue_exit(&ring);
return 0;
}
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