tools/thermal/lib/mainloop.c

   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
  11 static int epfd = -1;
  12 static sig_atomic_t exit_mainloop;
  13
  14 struct mainloop_data {
  15         mainloop_callback_t cb;
  16         void *data;
  17         int fd;
  18 };
  19
  20 #define MAX_EVENTS 10
  21
  22 int 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
  53 int 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
  79 int 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
  87 int mainloop_init(void)
  88 {
  89         epfd = epoll_create(2);
  90         if (epfd < 0)
  91                 return -1;
  92
  93         return 0;
  94 }
  95
  96 void mainloop_exit(void)
  97 {
  98         exit_mainloop = 1;
  99 }
 100
 101 void mainloop_fini(void)
 102 {
 103         close(epfd);
 104 }