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

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