1 /*
2 * Copyright (c) 2020 Linaro Limited
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 *
6 * This sample application is roughly based on the sample code in Linux
7 * manpage for eventfd().
8 */
9 #include <sys/eventfd.h>
10 #include <unistd.h>
11 #include <stdlib.h>
12 #include <stdio.h>
13 #include <stdint.h>
14
15 #define fatal(msg) \
16 do { perror(msg); exit(EXIT_FAILURE); } while (0)
17
18 /* As Zephyr doesn't provide command-line args, emulate them. */
19 char *input_argv[] = {"argv0", "1", "2", "3", "4"};
20
21 int efd;
22 int g_argc;
23 char **g_argv;
24
writer(void)25 void writer(void)
26 {
27 int j;
28 uint64_t u;
29 ssize_t s;
30
31 for (j = 1; j < g_argc; j++) {
32 printf("Writing %s to efd\n", g_argv[j]);
33 u = strtoull(g_argv[j], NULL, 0);
34 s = write(efd, &u, sizeof(uint64_t));
35 if (s != sizeof(uint64_t)) {
36 fatal("write");
37 }
38 }
39 printf("Completed write loop\n");
40 }
41
reader(void)42 void reader(void)
43 {
44 uint64_t u;
45 ssize_t s;
46
47 sleep(1);
48
49 printf("About to read\n");
50 s = read(efd, &u, sizeof(uint64_t));
51 if (s != sizeof(uint64_t)) {
52 fatal("read");
53 }
54 printf("Read %llu (0x%llx) from efd\n",
55 (unsigned long long)u, (unsigned long long)u);
56 }
57
main(int argc,char * argv[])58 int main(int argc, char *argv[])
59 {
60 argv = input_argv;
61 argc = sizeof(input_argv) / sizeof(input_argv[0]);
62
63 if (argc < 2) {
64 fprintf(stderr, "Usage: %s <num>...\n", argv[0]);
65 exit(EXIT_FAILURE);
66 }
67
68 g_argc = argc;
69 g_argv = argv;
70
71 efd = eventfd(0, 0);
72 if (efd == -1) {
73 fatal("eventfd");
74 }
75
76 writer();
77 reader();
78
79 printf("Finished\n");
80
81 return 0;
82 }
83
