source: example/io/attach-end.c @ 830edc6

Last change on this file since 830edc6 was d1eb9c0, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Fixed typo

  • Property mode set to 100644
File size: 2.4 KB
Line 
1/*
2This is an example that uses io_uring with attach mode.
3It demonstrates the what happens if the original ring is deleted before the other.
4It uses liburing for simplicity.
5*/
6
7#include <stdio.h>
8#include <stdlib.h>
9#include <string.h>
10
11#include <errno.h>
12#include <fcntl.h>
13#include <unistd.h>
14
15#include <liburing.h>
16
17
18char buffer1[1024];
19char buffer2[1024];
20
21static void test_read(struct io_uring * ring, int fd) {
22        printf("Testing ring %d\n", ring->ring_fd);
23        struct io_uring_sqe * sqe = io_uring_get_sqe(ring);
24        io_uring_prep_read(sqe, fd, buffer2, 1024, 0);
25
26        io_uring_submit(ring);
27
28        struct io_uring_cqe *cqe;
29        int ret = io_uring_wait_cqe(ring, &cqe);
30        if( ret < 0) {
31                fprintf(stderr, "ioring wait failed: (%d) %s\n", -ret, strerror(-ret));
32                exit(EXIT_FAILURE);
33        }
34        io_uring_cqe_seen(ring, cqe);
35
36        ret = memcmp(buffer1, buffer2, 1024);
37        if(ret != 0) {
38                fprintf(stderr, "files are different!\n");
39                exit(EXIT_FAILURE);
40        }
41}
42
43int main() {
44        const char * path = __FILE__;
45
46        int fd = open(path, 0, O_RDONLY);
47        if( fd < 0) {
48                fprintf(stderr, "Can't open file: (%d) %s\n", errno, strerror(errno));
49                return 1;
50        }
51
52        int ret = read(fd, buffer1, 1024);
53        if( ret < 0 ) {
54                fprintf(stderr, "Can't read file: (%d) %s\n", errno, strerror(errno));
55                return 1;
56        }
57
58        struct io_uring first_ring;
59        io_uring_queue_init(8, &first_ring, 0);
60        printf("Created first ring: %d\n", first_ring.ring_fd);
61
62        test_read(&first_ring, fd);
63
64
65        struct io_uring second_ring;
66        struct io_uring_params p;
67        memset(&p, '\0', sizeof(struct io_uring_params));
68        p.flags |= IORING_SETUP_ATTACH_WQ;
69        p.wq_fd = first_ring.ring_fd;
70        io_uring_queue_init_params(8, &second_ring, &p);
71        printf("Attached second ring: %d\n", second_ring.ring_fd);
72
73        test_read(&second_ring, fd);
74
75        printf("Deleting first ring: %d\n", first_ring.ring_fd);
76        io_uring_queue_exit(&first_ring);
77
78        printf("Sleeping (for good measure)\n");
79
80        usleep( 1000000 );
81
82        test_read(&second_ring, fd);
83
84        struct io_uring third_ring;
85        memset(&p, '\0', sizeof(struct io_uring_params));
86        p.flags |= IORING_SETUP_ATTACH_WQ;
87        p.wq_fd = second_ring.ring_fd;
88        io_uring_queue_init_params(8, &third_ring, &p);
89        printf("Attached third ring: %d\n", third_ring.ring_fd);
90
91        test_read(&third_ring, fd);
92
93        printf("Deleting second ring: %d\n", second_ring.ring_fd);
94        io_uring_queue_exit(&second_ring);
95
96        printf("Sleeping (for good measure)\n");
97
98        usleep( 1000000 );
99
100        io_uring_queue_exit(&third_ring);
101
102        close(fd);
103
104        return 0;
105
106}
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