iankelling.org Git - evhz/blob - evhz.c

   1 #include <string.h>
   2 #include <stdio.h>
   3 #include <linux/input.h>
   4 #include <fcntl.h>
   5 #include <signal.h>
   6
   7 #define EVENTS 50
   8 #define HZ_LIST 64
   9
  10 typedef struct event_s {
  11         int fd;
  12         int hz[HZ_LIST];
  13         int count;
  14         double prvtime;
  15 } event_t;
  16
  17 int quit = 0;
  18
  19 void sigint() {
  20         signal(SIGINT, sigint);
  21         quit = 1;
  22 }
  23
  24 int main(int argc, char **argv) {
  25         int i;
  26         event_t events[EVENTS];
  27
  28         signal(SIGINT, sigint);
  29
  30         printf("Press CTRL-C to exit.\n\n");
  31
  32         memset(events, 0, sizeof(events));
  33
  34         for(i = 0; i < EVENTS; i++) {
  35                 char device[18];
  36
  37                 sprintf(device, "/dev/input/event%i", i);
  38                 events[i].fd = open(device, O_RDONLY);
  39
  40                 if(events[i].fd != -1) {
  41                         char name[128];
  42                         ioctl(events[i].fd, EVIOCGNAME(sizeof(name)), name);
  43                         printf("event%i: %s\n", i, name);
  44                 }
  45         }
  46
  47         while(!quit) {
  48                 fd_set set;
  49
  50                 FD_ZERO(&set);
  51
  52                 for(i = 0; i < EVENTS; i++) {
  53                         if(events[i].fd != -1) {
  54                                 FD_SET(events[i].fd, &set);
  55                         }
  56                 }
  57
  58                 if(select(FD_SETSIZE, &set, NULL, NULL, NULL) > 0) {
  59                         int bytes;
  60                         struct input_event event;
  61
  62                         for(i = 0; i < EVENTS; i++) {
  63                                 if(events[i].fd == -1) {
  64                                         continue;
  65                                 }
  66
  67                                 if(!FD_ISSET(events[i].fd, &set)) {
  68                                         continue;
  69                                 }
  70
  71                                 bytes = read(events[i].fd, &event, sizeof(event));
  72
  73                                 if(bytes != sizeof(event)) {
  74                                         continue;
  75                                 }
  76
  77                                 if(event.type == EV_REL) {
  78                                         double time;
  79                                         int hz;
  80
  81                                         time = event.time.tv_sec * 1000 + event.time.tv_usec / 1000;
  82                                         hz = 1000 / (time - events[i].prvtime);
  83
  84                                         if(hz > 0) {
  85                                                 int avghz;
  86                                                 int j;
  87
  88                                                 events[i].count++;
  89                                                 events[i].hz[events[i].count & (HZ_LIST - 1)] = hz;
  90
  91                                                 avghz = 0;
  92
  93                                                 for(j = 0; j < HZ_LIST; j++) {
  94                                                         avghz += events[i].hz[j];
  95                                                 }
  96
  97                                                 avghz /= (events[i].count > HZ_LIST) ? HZ_LIST : events[i].count;
  98
  99                                                 printf("event%i: latest hz = %i (average hz = %i)\n", i, hz, avghz);
 100                                         }
 101
 102                                         events[i].prvtime = time;
 103                                 }
 104                         }
 105                 }
 106         }
 107
 108         for(i = 0; i < EVENTS; i++) {
 109                 if(events[i].fd != -1) {
 110                         close(events[i].fd);
 111                 }
 112         }
 113 }