aft.c: Silence scan-build warning.
[paraslash.git] / alsa_write.c
index 8e3688f..a4863a5 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
 #include <regex.h>
 #include <sys/types.h>
-#include <dirent.h>
 #include <alsa/asoundlib.h>
 #include <sys/time.h>
-#include <stdbool.h>
 
 #include "para.h"
 #include "fd.h"
 #include "alsa_write.cmdline.h"
 #include "error.h"
 
-/** always use 16 bit little endian */
-#define FORMAT SND_PCM_FORMAT_S16_LE
-
 /** Data specific to the alsa writer. */
 struct private_alsa_write_data {
        /** The alsa handle */
        snd_pcm_t *handle;
-       /** Determined and set by alsa_open(). */
-       int bytes_per_frame; /* TODO: Kill this after btr switch */
-       /** The approximate maximum buffer duration in us. */
-       unsigned buffer_time;
-       /* Number of frames that fit into the buffer. */
-       snd_pcm_uframes_t buffer_frames;
+       /** Determined and set by alsa_init(). */
+       int bytes_per_frame;
        /**
-        * The samplerate given by command line option or the decoder
+        * The sample rate given by command line option or the decoder
         * of the writer node group.
         */
-       unsigned samplerate;
+       unsigned sample_rate;
+       snd_pcm_format_t sample_format;
        /**
         * The number of channels, given by command line option or the
         * decoder of the writer node group.
         */
        unsigned channels;
+       struct timeval drain_barrier;
+       /* File descriptor for select(). */
+       int poll_fd;
 };
 
+static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf)
+{
+       switch (sf) {
+       case SF_S8: return SND_PCM_FORMAT_S8;
+       case SF_U8: return SND_PCM_FORMAT_U8;
+       case SF_S16_LE: return SND_PCM_FORMAT_S16_LE;
+       case SF_S16_BE: return SND_PCM_FORMAT_S16_BE;
+       case SF_U16_LE: return SND_PCM_FORMAT_U16_LE;
+       case SF_U16_BE: return SND_PCM_FORMAT_U16_BE;
+       default: return SND_PCM_FORMAT_S16_LE;
+       }
+}
+
 /* Install PCM software and hardware configuration. */
 static int alsa_init(struct private_alsa_write_data *pad,
                struct alsa_write_args_info *conf)
@@ -63,217 +71,149 @@ static int alsa_init(struct private_alsa_write_data *pad,
        snd_pcm_hw_params_t *hwparams;
        snd_pcm_sw_params_t *swparams;
        snd_pcm_uframes_t start_threshold, stop_threshold;
-       snd_pcm_uframes_t period_size;
-       int err;
+       snd_pcm_uframes_t buffer_size, period_size;
+       snd_output_t *log;
+       unsigned buffer_time;
+       int ret;
+       const char *msg;
 
        PARA_INFO_LOG("opening %s\n", conf->device_arg);
-       err = snd_pcm_open(&pad->handle, conf->device_arg,
+       msg = "unable to open pcm";
+       ret = snd_pcm_open(&pad->handle, conf->device_arg,
                SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
-       if (err < 0)
-               return -E_PCM_OPEN;
-
+       if (ret < 0)
+               goto fail;
        snd_pcm_hw_params_alloca(&hwparams);
-       snd_pcm_sw_params_alloca(&swparams);
-       if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
-               return -E_BROKEN_CONF;
-       if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
-                       SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
-               return -E_ACCESS_TYPE;
-       if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
-               return -E_SAMPLE_FORMAT;
-       if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
-                       pad->channels) < 0)
-               return -E_CHANNEL_COUNT;
-       if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
-                       &pad->samplerate, NULL) < 0)
-               return -E_SET_RATE;
-       err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
-               &pad->buffer_time, NULL);
-       if (err < 0 || !pad->buffer_time)
-               return -E_GET_BUFFER_TIME;
-       PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
-       if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
-                       &pad->buffer_time, NULL) < 0)
-               return -E_SET_BUFFER_TIME;
-       if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
-               return -E_HW_PARAMS;
+       msg = "Broken alsa configuration";
+       ret = snd_pcm_hw_params_any(pad->handle, hwparams);
+       if (ret < 0)
+               goto fail;
+       msg = "access type not available";
+       ret = snd_pcm_hw_params_set_access(pad->handle, hwparams,
+               SND_PCM_ACCESS_RW_INTERLEAVED);
+       if (ret < 0)
+               goto fail;
+       msg = "sample format not available";
+       ret = snd_pcm_hw_params_set_format(pad->handle, hwparams,
+               pad->sample_format);
+       if (ret < 0)
+               goto fail;
+       msg = "channels count not available";
+       ret = snd_pcm_hw_params_set_channels(pad->handle, hwparams,
+               pad->channels);
+       if (ret < 0)
+               goto fail;
+       msg = "could not set sample rate";
+       ret = snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
+               &pad->sample_rate, NULL);
+       if (ret < 0)
+               goto fail;
+       msg = "unable to get buffer time";
+       ret = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time,
+               NULL);
+       if (ret < 0 || buffer_time == 0)
+               goto fail;
+       msg = "could not set buffer time";
+       ret = snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
+               &buffer_time, NULL);
+       if (ret < 0)
+               goto fail;
+       msg = "unable to install hw params";
+       ret = snd_pcm_hw_params(pad->handle, hwparams);
+       if (ret < 0)
+               goto fail;
        snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
-       snd_pcm_hw_params_get_buffer_size(hwparams, &pad->buffer_frames);
-       PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", pad->buffer_frames,
-               period_size);
-       if (period_size == pad->buffer_frames)
-               return -E_BAD_PERIOD;
+       snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
+       msg = "period size equals buffer size";
+       if (period_size == buffer_size)
+               goto fail;
+
+       /* software parameter setup */
+       snd_pcm_sw_params_alloca(&swparams);
        snd_pcm_sw_params_current(pad->handle, swparams);
        snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
-       if (pad->buffer_frames < 1)
+       if (buffer_size < 1)
                start_threshold = 1;
        else
-               start_threshold = PARA_MIN(pad->buffer_frames,
-                       (snd_pcm_uframes_t)pad->samplerate);
-       if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
-                       start_threshold) < 0)
-               return -E_START_THRESHOLD;
-       stop_threshold = pad->buffer_frames;
-       if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
-                       stop_threshold) < 0)
-               return -E_STOP_THRESHOLD;
-       if (snd_pcm_sw_params(pad->handle, swparams) < 0)
-               PARA_WARNING_LOG("unable to install sw params\n");
-       pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
-               * pad->channels / 8;
-       if (pad->bytes_per_frame <= 0)
-               return -E_PHYSICAL_WIDTH;
-       PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
-       if (snd_pcm_nonblock(pad->handle, 1))
-               PARA_ERROR_LOG("failed to set nonblock mode\n");
-       return 1;
-}
-
-/* Open an instance of the alsa writer. */
-static int alsa_open_nobtr(struct writer_node *wn)
-{
-       struct alsa_write_args_info *conf = wn->conf;
-       struct writer_node_group *wng = wn->wng;
-       struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
-
-       wn->private_data = pad;
-       if (!conf->samplerate_given && wng->samplerate)
-               pad->samplerate = *wng->samplerate;
-       else
-               pad->samplerate = conf->samplerate_arg;
-       if (!conf->channels_given && wng->channels)
-               pad->channels = *wng->channels;
-       else
-               pad->channels = conf->channels_arg;
-       PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
-       return 1;
-}
-
-static int alsa_open_btr(struct writer_node *wn)
-{
-       struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
-
-       wn->private_data = pad;
-       return 1;
-}
-static int alsa_open(struct writer_node *wn)
-{
-       if (wn->btrn)
-               return alsa_open_btr(wn);
-       return alsa_open_nobtr(wn);
-}
-
-static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
-{
-       struct private_alsa_write_data *pad = wn->private_data;
-       struct writer_node_group *wng = wn->wng;
-       struct timeval tv;
-       snd_pcm_sframes_t avail, underrun;
-
-       if (!pad->handle)
-               return 1;
-       if (wn->btrn) {
-               int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
-               if (ret == 0)
-                       return 1;
-               if (ret < 0) {
-                       underrun = 10;
-                       goto timeout;
+               start_threshold = PARA_MIN(buffer_size,
+                       (snd_pcm_uframes_t)pad->sample_rate);
+       msg = "could not set start threshold";
+       ret = snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
+               start_threshold);
+       if (ret < 0)
+               goto fail;
+       stop_threshold = buffer_size;
+       msg = "could not set stop threshold";
+       ret = snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
+               stop_threshold);
+       if (ret < 0)
+               goto fail;
+       msg = "unable to install sw params";
+       ret = snd_pcm_sw_params(pad->handle, swparams);
+       if (ret < 0)
+               goto fail;
+       msg = "unable to determine bytes per frame";
+       ret = snd_pcm_format_physical_width(pad->sample_format);
+       if (ret <= 0)
+               goto fail;
+       pad->bytes_per_frame = ret * pad->channels / 8;
+       msg = "failed to set alsa handle to nonblock mode";
+       ret = snd_pcm_nonblock(pad->handle, 1);
+       if (ret < 0)
+               goto fail;
+       ret = snd_output_buffer_open(&log);
+       if (ret == 0) {
+               char *buf;
+               PARA_INFO_LOG("dumping alsa configuration\n");
+               snd_pcm_dump(pad->handle, log);
+               snd_output_buffer_string(log, &buf);
+               for (;;) {
+                       char *p = strchr(buf, '\n');
+                       if (!p) /* omit last output line, it's empty */
+                               break;
+                       *p = '\0';
+                       PARA_INFO_LOG("%s\n", buf);
+                       buf = p + 1;
                }
-       } else {
-               if (*wng->loaded - wn->written < pad->bytes_per_frame)
-                       return 1;
+               snd_output_close(log);
        }
-       /*
-        * Data is available to be written to the alsa handle.  Compute number
-        * of milliseconds until next buffer underrun would occur.
-        *
-        * snd_pcm_avail_update() updates the current available count of
-        * samples for writing.  It is a light method to obtain current stream
-        * position, because it does not require the user <-> kernel context
-        * switch, but the value is less accurate, because ring buffer pointers
-        * are updated in kernel drivers only when an interrupt occurs.
-        */
-       avail = snd_pcm_avail_update(pad->handle);
-       if (avail < 0)
-               avail = 0;
-       underrun = (pad->buffer_frames - avail) * pad->buffer_time
-               / pad->buffer_frames / 1000;
-       if (underrun < 50)
-               underrun = 50;
-       underrun -= 50;
-timeout:
-       ms2tv(underrun, &tv);
-       if (tv_diff(&s->timeout, &tv, NULL) > 0)
-               s->timeout = tv;
-       //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
        return 1;
+fail:
+       if (ret < 0)
+               PARA_ERROR_LOG("%s: %s\n", msg, snd_strerror(-ret));
+       else
+               PARA_ERROR_LOG("%s\n", msg);
+       return -E_ALSA;
 }
 
-static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
+static void alsa_write_pre_select(struct sched *s, struct task *t)
 {
+       struct pollfd pfd;
        struct writer_node *wn = container_of(t, struct writer_node, task);
-       alsa_write_pre_select(s, wn);
-}
-
-static void xrun(snd_pcm_t *handle)
-{
-       snd_pcm_status_t *status;
-       int ret;
-       struct timeval tv, diff;
+       struct private_alsa_write_data *pad = wn->private_data;
+       int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
 
-       snd_pcm_status_alloca(&status);
-       ret = snd_pcm_status(handle, status);
-       if (ret < 0)
+       if (pad)
+               pad->poll_fd = -1;
+       if (ret == 0)
                return;
-       if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
+       if (!pad) {
+               sched_min_delay(s);
                return;
-       snd_pcm_status_get_trigger_tstamp(status, &tv);
-       tv_diff(now, &tv, &diff);
-       PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
-}
-
-static int alsa_write_post_select(__a_unused struct sched *s,
-               struct writer_node *wn)
-{
-       struct private_alsa_write_data *pad = wn->private_data;
-       struct writer_node_group *wng = wn->wng;
-       size_t bytes = *wng->loaded - wn->written;
-       unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
-       snd_pcm_sframes_t ret, frames, avail;
-
-       if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
-               wn->written = *wng->loaded;
-               return *wng->input_error;
-       }
-       if (!bytes) /* no data available */
-               return 0;
-       if (!pad->handle) {
-               int err = alsa_init(pad, wn->conf);
-               if (err < 0)
-                       return err;
        }
-       frames = bytes / pad->bytes_per_frame;
-       if (!frames) /* less than a single frame available */
-               return 0;
-       avail = snd_pcm_avail_update(pad->handle);
-       if (avail <= 0)
-               return 0;
-       frames = PARA_MIN(frames, avail);
-       ret = snd_pcm_writei(pad->handle, data, frames);
-       if (ret >= 0) {
-               wn->written += ret * pad->bytes_per_frame;
-               return 1;
+       if (ret < 0) {
+               sched_request_barrier_or_min_delay(&pad->drain_barrier, s);
+               return;
        }
-       if (ret == -EPIPE) {
-               xrun(pad->handle);
-               snd_pcm_prepare(pad->handle);
-               return 0;
+       ret = snd_pcm_poll_descriptors(pad->handle, &pfd, 1);
+       if (ret < 0) {
+               PARA_ERROR_LOG("could not get alsa poll fd: %s\n",
+                       snd_strerror(-ret));
+               t->error = -E_ALSA;
+               return;
        }
-       PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
-       if (ret == -EAGAIN)
-               return 0;
-       return -E_ALSA_WRITE;
+       pad->poll_fd = pfd.fd;
+       para_fd_set(pfd.fd, &s->rfds, &s->max_fileno);
 }
 
 static void alsa_close(struct writer_node *wn)
@@ -281,20 +221,20 @@ static void alsa_close(struct writer_node *wn)
        struct private_alsa_write_data *pad = wn->private_data;
        PARA_INFO_LOG("closing writer node %p\n", wn);
 
-       if (pad->handle) {
-               /*
-                * It's OK to have a blocking operation here because we already
-                * made sure that the PCM output buffer is (nearly) empty.
-                */
-               snd_pcm_nonblock(pad->handle, 0);
-               snd_pcm_drain(pad->handle);
-               snd_pcm_close(pad->handle);
-               snd_config_update_free_global();
-       }
+       if (!pad)
+               return;
+       /*
+        * It's OK to have a blocking operation here because we already made
+        * sure that the PCM output buffer is (nearly) empty.
+        */
+       snd_pcm_nonblock(pad->handle, 0);
+       snd_pcm_drain(pad->handle);
+       snd_pcm_close(pad->handle);
+       snd_config_update_free_global();
        free(pad);
 }
 
-static void alsa_write_post_select_btr(__a_unused struct sched *s,
+static void alsa_write_post_select(__a_unused struct sched *s,
                struct task *t)
 {
        struct writer_node *wn = container_of(t, struct writer_node, task);
@@ -302,7 +242,7 @@ static void alsa_write_post_select_btr(__a_unused struct sched *s,
        struct btr_node *btrn = wn->btrn;
        char *data;
        size_t bytes;
-       snd_pcm_sframes_t frames, avail;
+       snd_pcm_sframes_t frames;
        int ret;
 
 again:
@@ -312,86 +252,87 @@ again:
                return;
        btr_merge(btrn, wn->min_iqs);
        bytes = btr_next_buffer(btrn, &data);
-       if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
+       if (ret < 0 || bytes < wn->min_iqs) { /* eof */
                assert(btr_no_parent(btrn));
-               ret = -E_ALSA_EOF;
-               if (!pad->handle)
+               ret = -E_WRITE_COMMON_EOF;
+               if (!pad)
                        goto err;
                /* wait until pending frames are played */
-               avail = snd_pcm_avail_update(pad->handle);
-               if (avail + 1000 > pad->buffer_frames)
+               if (pad->drain_barrier.tv_sec == 0) {
+                       PARA_DEBUG_LOG("waiting for device to drain\n");
+                       tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000),
+                               &pad->drain_barrier);
+                       return;
+               }
+               if (tv_diff(now, &pad->drain_barrier, NULL) > 0)
                        goto err;
-               PARA_DEBUG_LOG("waiting for device to drain\n");
                return;
        }
-       if (!pad->handle) {
-               struct alsa_write_args_info *conf = wn->conf;
+       if (!pad) {
+               int32_t val;
+
                if (bytes == 0) /* no data available */
                        return;
-               /* defaults */
-               pad->samplerate = conf->samplerate_arg;
-               pad->channels = conf->channels_arg;
-               if (!conf->samplerate_given) { /* config option trumps btr_exec */
-                       int32_t rate;
-                       ret = get_btr_samplerate(btrn, &rate);
-                       if (ret < 0)
-                               goto err;
-                       pad->samplerate = rate;
-               }
-               if (!conf->channels_given) {
-                       int32_t ch;
-                       ret = get_btr_channels(btrn, &ch);
-                       if (ret < 0)
-                               goto err;
-                       pad->channels = ch;
-               }
-               PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
-               ret = 1;
+               pad = para_calloc(sizeof(*pad));
+               get_btr_sample_rate(btrn, &val);
+               pad->sample_rate = val;
+               get_btr_channels(btrn, &val);
+               pad->channels = val;
+               get_btr_sample_format(btrn, &val);
+               pad->sample_format = get_alsa_pcm_format(val);
+
+               PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels,
+                       pad->sample_rate);
                ret = alsa_init(pad, wn->conf);
-               if (ret < 0)
+               if (ret < 0) {
+                       free(pad);
                        goto err;
+               }
+               wn->private_data = pad;
                wn->min_iqs = pad->bytes_per_frame;
+               goto again;
        }
-       frames = bytes / pad->bytes_per_frame;
-       avail = snd_pcm_avail_update(pad->handle);
-       if (avail <= 0)
+       if (pad->poll_fd < 0 || !FD_ISSET(pad->poll_fd, &s->rfds))
                return;
-       frames = PARA_MIN(frames, avail);
-       //PARA_CRIT_LOG("writing %ld frames\n", frames);
+       frames = bytes / pad->bytes_per_frame;
        frames = snd_pcm_writei(pad->handle, data, frames);
-       if (frames >= 0) {
+       if (frames == 0 || frames == -EAGAIN) {
+               /*
+                * The alsa poll fd was ready for IO but we failed to write to
+                * the alsa handle. This means another event is pending. We
+                * don't care about that but we have to dispatch the event in
+                * order to avoid a busy loop. So we simply read from the poll
+                * fd.
+                */
+               char buf[100];
+               if (read(pad->poll_fd, buf, 100))
+                       do_nothing;
+               return;
+       }
+       if (frames > 0) {
                btr_consume(btrn, frames * pad->bytes_per_frame);
                goto again;
        }
        if (frames == -EPIPE) {
-               xrun(pad->handle);
+               PARA_WARNING_LOG("underrun (tried to write %zu bytes)\n", bytes);
                snd_pcm_prepare(pad->handle);
                return;
        }
-       PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
-       if (frames == -EAGAIN)
-               return;
-       ret = -E_ALSA_WRITE;
+       PARA_ERROR_LOG("alsa write error: %s\n", snd_strerror(-frames));
+       ret = -E_ALSA;
 err:
        assert(ret < 0);
+       btr_remove_node(btrn);
        t->error = ret;
 }
 
-__malloc static void *alsa_parse_config(const char *options)
+__malloc static void *alsa_parse_config_or_die(const char *options)
 {
-       int ret;
-       struct alsa_write_args_info *conf
-               = para_calloc(sizeof(struct alsa_write_args_info));
+       struct alsa_write_args_info *conf = para_calloc(sizeof(*conf));
 
-       PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
-       ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
-       if (ret)
-               goto err_out;
-       PARA_INFO_LOG("help given: %d\n", conf->help_given);
+       /* exits on errors */
+       alsa_cmdline_parser_string(options, conf, "alsa_write");
        return conf;
-err_out:
-       free(conf);
-       return NULL;
 }
 
 static void alsa_free_config(void *conf)
@@ -404,20 +345,17 @@ static void alsa_free_config(void *conf)
  *
  * \param w Pointer to the writer to initialize.
  *
- * \sa \ref struct writer.
+ * \sa struct \ref writer.
  */
 void alsa_write_init(struct writer *w)
 {
        struct alsa_write_args_info dummy;
 
        alsa_cmdline_parser_init(&dummy);
-       w->open = alsa_open;
        w->close = alsa_close;
        w->pre_select = alsa_write_pre_select;
-       w->pre_select_btr = alsa_write_pre_select_btr;
        w->post_select = alsa_write_post_select;
-       w->post_select_btr = alsa_write_post_select_btr;
-       w->parse_config = alsa_parse_config;
+       w->parse_config_or_die = alsa_parse_config_or_die;
        w->shutdown = NULL; /* nothing to do */
        w->free_config = alsa_free_config;
        w->help = (struct ggo_help) {