/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;
}

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