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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 "../src/liburing.h"
int main(int argc, char *argv[])
{
struct io_uring_params p;
struct io_uring_sq sq;
struct io_uring_cq cq;
int i, fd, ring_fd, ret, pending, done;
struct io_uring_iocb *iocb;
struct io_uring_event *ev;
off_t offset;
void *buf;
if (argc < 2) {
printf("%s: file\n", argv[0]);
return 1;
}
memset(&p, 0, sizeof(p));
p.flags = IORING_SETUP_IOPOLL;
ring_fd = io_uring_queue_init(4, &p, NULL, &sq, &cq);
if (ring_fd < 0) {
fprintf(stderr, "queue_init: %s\n", strerror(-ring_fd));
return 1;
}
fd = open(argv[1], O_RDONLY | O_DIRECT);
if (fd < 0) {
perror("open");
return 1;
}
if (posix_memalign(&buf, 4096, 4096))
return 1;
offset = 0;
do {
iocb = io_uring_get_iocb(&sq);
if (!iocb)
break;
iocb->opcode = IORING_OP_READ;
iocb->flags = 0;
iocb->ioprio = 0;
iocb->fd = fd;
iocb->off = offset;
iocb->addr = buf;
iocb->len = 4096;
offset += 4096;
} while (1);
ret = io_uring_submit(ring_fd, &sq);
if (ret < 0) {
fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret));
return 1;
}
done = 0;
pending = ret;
for (i = 0; i < pending; i++) {
ev = NULL;
ret = io_uring_get_completion(ring_fd, &cq, &ev);
if (ret < 0) {
fprintf(stderr, "io_uring_get_completion: %s\n", strerror(-ret));
return 1;
}
done++;
if (ev->res != 4096) {
fprintf(stderr, "ret=%d, wanted 4096\n", ev->res);
return 1;
}
}
printf("Submitted=%d, completed=%d\n", pending, done);
close(fd);
io_uring_queue_exit(ring_fd, &sq, &cq);
return 0;
}
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