1// SPDX-License-Identifier: LGPL-2.1+
2// Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org>
3#include <stdlib.h>
4#include <errno.h>
5#include <unistd.h>
6#include <signal.h>
7#include <sys/epoll.h>
8#include "mainloop.h"
9#include "log.h"
10
11static int epfd = -1;
12static sig_atomic_t exit_mainloop;
13
14struct mainloop_data {
15 mainloop_callback_t cb;
16 void *data;
17 int fd;
18};
19
20#define MAX_EVENTS 10
21
22int mainloop(unsigned int timeout)
23{
24 int i, nfds;
25 struct epoll_event events[MAX_EVENTS];
26 struct mainloop_data *md;
27
28 if (epfd < 0)
29 return -1;
30
31 for (;;) {
32
33 nfds = epoll_wait(epfd, events, MAX_EVENTS, timeout);
34
35 if (exit_mainloop || !nfds)
36 return 0;
37
38 if (nfds < 0) {
39 if (errno == EINTR)
40 continue;
41 return -1;
42 }
43
44 for (i = 0; i < nfds; i++) {
45 md = events[i].data.ptr;
46
47 if (md->cb(md->fd, md->data) > 0)
48 return 0;
49 }
50 }
51}
52
53int mainloop_add(int fd, mainloop_callback_t cb, void *data)
54{
55 struct epoll_event ev = {
56 .events = EPOLLIN,
57 };
58
59 struct mainloop_data *md;
60
61 md = malloc(sizeof(*md));
62 if (!md)
63 return -1;
64
65 md->data = data;
66 md->cb = cb;
67 md->fd = fd;
68
69 ev.data.ptr = md;
70
71 if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev) < 0) {
72 free(md);
73 return -1;
74 }
75
76 return 0;
77}
78
79int mainloop_del(int fd)
80{
81 if (epoll_ctl(epfd, EPOLL_CTL_DEL, fd, NULL) < 0)
82 return -1;
83
84 return 0;
85}
86
87int mainloop_init(void)
88{
89 epfd = epoll_create(2);
90 if (epfd < 0)
91 return -1;
92
93 return 0;
94}
95
96void mainloop_exit(void)
97{
98 exit_mainloop = 1;
99}
100
101void mainloop_fini(void)
102{
103 close(epfd);
104}
105

source code of linux/tools/thermal/lib/mainloop.c