tools/testing/selftests/alsa/global-timer.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This tool is used by the utimer test, and it allows us to
   4  * count the ticks of a global timer in a certain time frame
   5  * (which is set by `timeout` parameter).
   6  *
   7  * Author: Ivan Orlov <ivan.orlov0322@gmail.com>
   8  */
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <alsa/asoundlib.h>
  12 #include <time.h>
  13
  14 static int ticked;
  15 static void async_callback(snd_async_handler_t *ahandler)
  16 {
  17         ticked++;
  18 }
  19
  20 static char timer_name[64];
  21 static void bind_to_timer(int device, int subdevice, int timeout)
  22 {
  23         snd_timer_t *handle;
  24         snd_timer_params_t *params;
  25         snd_async_handler_t *ahandler;
  26
  27         time_t end;
  28
  29         sprintf(timer_name, "hw:CLASS=%d,SCLASS=%d,DEV=%d,SUBDEV=%d",
  30                 SND_TIMER_CLASS_GLOBAL, SND_TIMER_SCLASS_NONE,
  31                 device, subdevice);
  32
  33         snd_timer_params_alloca(&params);
  34
  35         if (snd_timer_open(&handle, timer_name, SND_TIMER_OPEN_NONBLOCK) < 0) {
  36                 perror("Can't open the timer");
  37                 exit(EXIT_FAILURE);
  38         }
  39
  40         snd_timer_params_set_auto_start(params, 1);
  41         snd_timer_params_set_ticks(params, 1);
  42         if (snd_timer_params(handle, params) < 0) {
  43                 perror("Can't set timer params");
  44                 exit(EXIT_FAILURE);
  45         }
  46
  47         if (snd_async_add_timer_handler(&ahandler, handle, async_callback, NULL) < 0) {
  48                 perror("Can't create a handler");
  49                 exit(EXIT_FAILURE);
  50         }
  51         end = time(NULL) + timeout;
  52         if (snd_timer_start(handle) < 0) {
  53                 perror("Failed to start the timer");
  54                 exit(EXIT_FAILURE);
  55         }
  56         printf("Timer has started\n");
  57         while (time(NULL) <= end) {
  58                 /*
  59                  * Waiting for the timeout to elapse. Can't use sleep here, as it gets
  60                  * constantly interrupted by the signal from the timer (SIGIO)
  61                  */
  62         }
  63         snd_timer_stop(handle);
  64         snd_timer_close(handle);
  65 }
  66
  67 int main(int argc, char *argv[])
  68 {
  69         int device, subdevice, timeout;
  70
  71         if (argc < 4) {
  72                 perror("Usage: %s <device> <subdevice> <timeout>");
  73                 return EXIT_FAILURE;
  74         }
  75
  76         setlinebuf(stdout);
  77
  78         device = atoi(argv[1]);
  79         subdevice = atoi(argv[2]);
  80         timeout = atoi(argv[3]);
  81
  82         bind_to_timer(device, subdevice, timeout);
  83
  84         printf("Total ticks count: %d\n", ticked);
  85
  86         return EXIT_SUCCESS;
  87 }