/test/timer.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include "../include/asoundlib.h"
 
void show_status(void *handle)
{
    int err;
    snd_timer_status_t *status;
    
    snd_timer_status_alloca(&status);
    if ((err = snd_timer_status(handle, status)) < 0) {
        fprintf(stderr, "timer status %i (%s)\n", err, snd_strerror(err));
        return;
    }
    printf("STATUS:\n");
    printf("  resolution = %li\n", snd_timer_status_get_resolution(status));
    printf("  lost = %li\n", snd_timer_status_get_lost(status));
    printf("  overrun = %li\n", snd_timer_status_get_overrun(status));
    printf("  queue = %li\n", snd_timer_status_get_queue(status));
}
 
void read_loop(void *handle, int master_ticks, int timeout)
{
    int count, err;
    struct pollfd *fds;
    snd_timer_read_t tr;
    
    count = snd_timer_poll_descriptors_count(handle);
    fds = calloc(count, sizeof(struct pollfd));
    if (fds == NULL) {
        fprintf(stderr, "malloc error\n");
        exit(EXIT_FAILURE);
    }
    while (master_ticks-- > 0) {
        if ((err = snd_timer_poll_descriptors(handle, fds, count)) < 0) {
            fprintf(stderr, "snd_timer_poll_descriptors error: %s\n", snd_strerror(err));
            exit(EXIT_FAILURE);
        }
        if ((err = poll(fds, count, timeout)) < 0) {
            fprintf(stderr, "poll error %i (%s)\n", err, strerror(err));
            exit(EXIT_FAILURE);
        }
        if (err == 0) {
            fprintf(stderr, "timer time out!!\n");
            exit(EXIT_FAILURE);
        }
        while (snd_timer_read(handle, &tr, sizeof(tr)) == sizeof(tr)) {
            printf("TIMER: resolution = %uns, ticks = %u\n",
                tr.resolution, tr.ticks);
        }
    }
    free(fds);
}
 
static void async_callback(snd_async_handler_t *ahandler)
{
    snd_timer_t *handle = snd_async_handler_get_timer(ahandler);
    int *acount = snd_async_handler_get_callback_private(ahandler);
    snd_timer_read_t tr;
    
    while (snd_timer_read(handle, &tr, sizeof(tr)) == sizeof(tr)) {
        printf("TIMER: resolution = %uns, ticks = %u\n",
            tr.resolution, tr.ticks);
    }
    (*acount)++;
}
 
int main(int argc, char *argv[])
{
    int idx, err;
    int class = SND_TIMER_CLASS_GLOBAL;
    int sclass = SND_TIMER_CLASS_NONE;
    int card = 0;
    int device = SND_TIMER_GLOBAL_SYSTEM;
    int subdevice = 0;
    int list = 0;
    int async = 0;
    int acount = 0;
    snd_timer_t *handle;
    snd_timer_id_t *id;
    snd_timer_info_t *info;
    snd_timer_params_t *params;
    char timername[64];
    snd_async_handler_t *ahandler;
 
    snd_timer_id_alloca(&id);
    snd_timer_info_alloca(&info);
    snd_timer_params_alloca(&params);
 
    idx = 1;
    while (idx < argc) {
        if (!strncmp(argv[idx], "class=", 5)) {
            class = atoi(argv[idx]+6);
        } else if (!strncmp(argv[idx], "sclass=", 6)) {
            sclass = atoi(argv[idx]+7);
        } else if (!strncmp(argv[idx], "card=", 5)) {
            card = atoi(argv[idx]+5);
        } else if (!strncmp(argv[idx], "device=", 7)) {
            device = atoi(argv[idx]+7);
        } else if (!strncmp(argv[idx], "subdevice=", 10)) {
            subdevice = atoi(argv[idx]+10);
        } else if (!strcmp(argv[idx], "list")) {
            list = 1;
        } else if (!strcmp(argv[idx], "async")) {
            async = 1;
        }
        idx++;
    }
    if (class == SND_TIMER_CLASS_SLAVE && sclass == SND_TIMER_SCLASS_NONE) {
        fprintf(stderr, "slave class is not set\n");
        exit(EXIT_FAILURE);
    }
    if (list) {
        snd_timer_query_t *qhandle;
        if ((err = snd_timer_query_open(&qhandle, "hw", 0)) < 0) {
            fprintf(stderr, "snd_timer_query_open error: %s\n", snd_strerror(err));
            exit(EXIT_FAILURE);
        }
        snd_timer_id_set_class(id, SND_TIMER_CLASS_NONE);
        while (1) {
            if ((err = snd_timer_query_next_device(qhandle, id)) < 0) {
                fprintf(stderr, "timer next device error: %s\n", snd_strerror(err));
                break;
            }
            if (snd_timer_id_get_class(id) < 0)
                break;
            printf("Timer device: class %i, sclass %i, card %i, device %i, subdevice %i\n",
                    snd_timer_id_get_class(id),
                    snd_timer_id_get_sclass(id),
                    snd_timer_id_get_card(id),
                    snd_timer_id_get_device(id),
                    snd_timer_id_get_subdevice(id));
        }
        snd_timer_query_close(qhandle);
        exit(EXIT_SUCCESS);
    }
    sprintf(timername, "hw:CLASS=%i,SCLASS=%i,CARD=%i,DEV=%i,SUBDEV=%i", class, sclass, card, device, subdevice);
    if ((err = snd_timer_open(&handle, timername, SND_TIMER_OPEN_NONBLOCK))<0) {
        fprintf(stderr, "timer open %i (%s)\n", err, snd_strerror(err));
        exit(EXIT_FAILURE);
    }
    printf("Using timer class %i, slave class %i, card %i, device %i, subdevice %i\n", class, sclass, card, device, subdevice);
    if ((err = snd_timer_info(handle, info)) < 0) {
        fprintf(stderr, "timer info %i (%s)\n", err, snd_strerror(err));
        exit(0);
    }
    printf("Timer info:\n");
    printf("  slave = %s\n", snd_timer_info_is_slave(info) ? "yes" : "no");
    printf("  card = %i\n", snd_timer_info_get_card(info));
    printf("  id = '%s'\n", snd_timer_info_get_id(info));
    printf("  name = '%s'\n", snd_timer_info_get_name(info));
    printf("  average resolution = %li\n", snd_timer_info_get_resolution(info));
    snd_timer_params_set_auto_start(params, 1);
    if (!snd_timer_info_is_slave(info)) {
        snd_timer_params_set_ticks(params, (1000000000 / snd_timer_info_get_resolution(info)) / 50); /* 50Hz */
        if (snd_timer_params_get_ticks(params) < 1)
            snd_timer_params_set_ticks(params, 1);
        printf("Using %li tick(s)\n", snd_timer_params_get_ticks(params));
    } else {
        snd_timer_params_set_ticks(params, 1);
    }
    if ((err = snd_timer_params(handle, params)) < 0) {
        fprintf(stderr, "timer params %i (%s)\n", err, snd_strerror(err));
        exit(0);
    }
    show_status(handle);
    if (async) {
        err = snd_async_add_timer_handler(&ahandler, handle, async_callback, &acount);
        if (err < 0) {
            fprintf(stderr, "unable to add async handler %i (%s)\n", err, snd_strerror(err));
            exit(EXIT_FAILURE);
        }
    }
    if ((err = snd_timer_start(handle)) < 0) {
        fprintf(stderr, "timer start %i (%s)\n", err, snd_strerror(err));
        exit(EXIT_FAILURE);
    }
    if (async) {
        /* because all other work is done in the signal handler,
           suspend the process */
        while (acount < 25)
            sleep(1);
        snd_timer_stop(handle);
    } else {
        read_loop(handle, 25, snd_timer_info_is_slave(info) ? 10000 : 25);
    }
    show_status(handle);
    snd_timer_close(handle);
    printf("Done\n");
    return EXIT_SUCCESS;
}