diff options
Diffstat (limited to 'src/tests/alsa-time-test.c')
| -rw-r--r-- | src/tests/alsa-time-test.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/tests/alsa-time-test.c b/src/tests/alsa-time-test.c new file mode 100644 index 0000000..dff95bb --- /dev/null +++ b/src/tests/alsa-time-test.c @@ -0,0 +1,251 @@ +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <assert.h> +#include <inttypes.h> +#include <time.h> +#include <unistd.h> +#include <pthread.h> + +#include <alsa/asoundlib.h> + +#define SAMPLE_RATE 44100 +#define CHANNELS 2 + +static uint64_t timespec_us(const struct timespec *ts) { + return + ts->tv_sec * 1000000LLU + + ts->tv_nsec / 1000LLU; +} + +int main(int argc, char *argv[]) { + const char *dev; + int r, cap, count = 0; + snd_pcm_hw_params_t *hwparams; + snd_pcm_sw_params_t *swparams; + snd_pcm_status_t *status; + snd_pcm_t *pcm; + unsigned rate = SAMPLE_RATE; + unsigned periods = 2; + snd_pcm_uframes_t boundary, buffer_size = SAMPLE_RATE/10; /* 100s */ + int dir = 1; + int fillrate; + struct timespec start, last_timestamp = { 0, 0 }; + uint64_t start_us, last_us = 0; + snd_pcm_sframes_t last_avail = 0, last_delay = 0; + struct pollfd *pollfds; + int n_pollfd; + int64_t sample_count = 0; + uint16_t *samples; + struct sched_param sp; + + r = -1; +#ifdef _POSIX_PRIORITY_SCHEDULING + sp.sched_priority = 5; + r = pthread_setschedparam(pthread_self(), SCHED_RR, &sp); +#endif + if (r) + printf("Could not get RT prio. :(\n"); + + snd_pcm_hw_params_alloca(&hwparams); + snd_pcm_sw_params_alloca(&swparams); + snd_pcm_status_alloca(&status); + + r = clock_gettime(CLOCK_MONOTONIC, &start); + assert(r == 0); + + start_us = timespec_us(&start); + + dev = argc > 1 ? argv[1] : "front:0"; + cap = argc > 2 ? atoi(argv[2]) : 0; + fillrate = argc > 3 ? atoi(argv[3]) : 1; + assert(fillrate > 0); + + samples = calloc(fillrate, CHANNELS*sizeof(uint16_t)); + assert(samples); + + if (cap == 0) + r = snd_pcm_open(&pcm, dev, SND_PCM_STREAM_PLAYBACK, 0); + else + r = snd_pcm_open(&pcm, dev, SND_PCM_STREAM_CAPTURE, 0); + assert(r == 0); + + r = snd_pcm_hw_params_any(pcm, hwparams); + assert(r == 0); + + r = snd_pcm_hw_params_set_rate_resample(pcm, hwparams, 0); + assert(r == 0); + + r = snd_pcm_hw_params_set_access(pcm, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED); + assert(r == 0); + + r = snd_pcm_hw_params_set_format(pcm, hwparams, SND_PCM_FORMAT_S16_LE); + assert(r == 0); + + r = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, NULL); + assert(r == 0); + + r = snd_pcm_hw_params_set_channels(pcm, hwparams, CHANNELS); + assert(r == 0); + + r = snd_pcm_hw_params_set_periods_integer(pcm, hwparams); + assert(r == 0); + + r = snd_pcm_hw_params_set_periods_near(pcm, hwparams, &periods, &dir); + assert(r == 0); + + r = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, &buffer_size); + assert(r == 0); + + r = snd_pcm_hw_params(pcm, hwparams); + assert(r == 0); + + r = snd_pcm_hw_params_current(pcm, hwparams); + assert(r == 0); + + r = snd_pcm_sw_params_current(pcm, swparams); + assert(r == 0); + + if (cap == 0) + r = snd_pcm_sw_params_set_avail_min(pcm, swparams, 1); + else + r = snd_pcm_sw_params_set_avail_min(pcm, swparams, 0); + assert(r == 0); + + r = snd_pcm_sw_params_set_period_event(pcm, swparams, 0); + assert(r == 0); + + r = snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size); + assert(r == 0); + r = snd_pcm_sw_params_set_start_threshold(pcm, swparams, buffer_size - (buffer_size % fillrate)); + assert(r == 0); + + r = snd_pcm_sw_params_get_boundary(swparams, &boundary); + assert(r == 0); + r = snd_pcm_sw_params_set_stop_threshold(pcm, swparams, boundary); + assert(r == 0); + + r = snd_pcm_sw_params_set_tstamp_mode(pcm, swparams, SND_PCM_TSTAMP_ENABLE); + assert(r == 0); + + r = snd_pcm_sw_params(pcm, swparams); + assert(r == 0); + + r = snd_pcm_sw_params_current(pcm, swparams); + assert(r == 0); + +/* assert(snd_pcm_hw_params_is_monotonic(hwparams) > 0); */ + + n_pollfd = snd_pcm_poll_descriptors_count(pcm); + assert(n_pollfd > 0); + + pollfds = malloc(sizeof(struct pollfd) * n_pollfd); + assert(pollfds); + + r = snd_pcm_poll_descriptors(pcm, pollfds, n_pollfd); + assert(r == n_pollfd); + + printf("Starting. Buffer size is %u frames\n", (unsigned int) buffer_size); + + if (cap) { + r = snd_pcm_start(pcm); + assert(r == 0); + } + + for (;;) { + snd_pcm_sframes_t avail, delay; + struct timespec now, timestamp; + unsigned short revents; + int handled = 0; + uint64_t now_us, timestamp_us; + snd_pcm_state_t state; + unsigned long long pos; + + r = poll(pollfds, n_pollfd, 0); + assert(r >= 0); + + r = snd_pcm_poll_descriptors_revents(pcm, pollfds, n_pollfd, &revents); + assert(r == 0); + + if (cap == 0) + assert((revents & ~POLLOUT) == 0); + else + assert((revents & ~POLLIN) == 0); + + avail = snd_pcm_avail(pcm); + assert(avail >= 0); + + r = snd_pcm_status(pcm, status); + assert(r == 0); + + /* This assertion fails from time to time. ALSA seems to be broken */ +/* assert(avail == (snd_pcm_sframes_t) snd_pcm_status_get_avail(status)); */ +/* printf("%lu %lu\n", (unsigned long) avail, (unsigned long) snd_pcm_status_get_avail(status)); */ + + snd_pcm_status_get_htstamp(status, ×tamp); + delay = snd_pcm_status_get_delay(status); + state = snd_pcm_status_get_state(status); + + r = clock_gettime(CLOCK_MONOTONIC, &now); + assert(r == 0); + + assert(!revents || avail > 0); + + if ((!cap && (avail >= fillrate)) || (cap && (unsigned)avail >= buffer_size)) { + snd_pcm_sframes_t sframes; + + if (cap == 0) + sframes = snd_pcm_writei(pcm, samples, fillrate); + else + sframes = snd_pcm_readi(pcm, samples, fillrate); + assert(sframes == fillrate); + + handled = fillrate; + sample_count += fillrate; + } + + if (!handled && + memcmp(×tamp, &last_timestamp, sizeof(timestamp)) == 0 && + avail == last_avail && + delay == last_delay) { + /* This is boring */ + continue; + } + + now_us = timespec_us(&now); + timestamp_us = timespec_us(×tamp); + + if (cap == 0) + pos = (unsigned long long) ((sample_count - handled - delay) * 1000000LU / SAMPLE_RATE); + else + pos = (unsigned long long) ((sample_count - handled + delay) * 1000000LU / SAMPLE_RATE); + + if (count++ % 50 == 0) + printf("Elapsed\tCPU\tALSA\tPos\tSamples\tavail\tdelay\trevents\thandled\tstate\n"); + + printf("%llu\t%llu\t%llu\t%llu\t%llu\t%li\t%li\t%i\t%i\t%i\n", + (unsigned long long) (now_us - last_us), + (unsigned long long) (now_us - start_us), + (unsigned long long) (timestamp_us ? timestamp_us - start_us : 0), + pos, + (unsigned long long) sample_count, + (signed long) avail, + (signed long) delay, + revents, + handled, + state); + + if (cap == 0) + /** When this assert is hit, most likely something bad + * happened, i.e. the avail jumped suddenly. */ + assert((unsigned) avail <= buffer_size); + + last_avail = avail; + last_delay = delay; + last_timestamp = timestamp; + last_us = now_us; + } + + return 0; +} |