[alsa-devel] [PATCH] alsa-plugins: fix polling and recovering in alsa-jack plugin
Hello.
This patch fixes polling in alsa-to-jack plugin. It makes poll()+_poll_revents() return correct values whenever there's something to read/write.
Additionally jack_deactivate() code makes it survive snd_pcm_recover().
It works for the code example I posted before, aplay, arecord, mozilla, etc.
Comments and suggestions are welcome.
--- diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 7a8b24d..a39fea5 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -42,6 +42,7 @@ typedef struct { unsigned int num_ports; unsigned int hw_ptr; unsigned int sample_bits; + snd_pcm_uframes_t min_avail;
unsigned int channels; snd_pcm_channel_area_t *areas; @@ -50,6 +51,41 @@ typedef struct { jack_client_t *client; } snd_pcm_jack_t;
+static inline int poll_blocked(snd_pcm_ioplug_t *io) +{ + static char buf[65536]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + if (io->state == SND_PCM_STATE_RUNNING) + { + avail = snd_pcm_avail_update(io->pcm); + if (avail >= 0 && avail < jack->min_avail) + { + read(io->poll_fd, &buf, sizeof buf); + return 1; + } + } + + return 0; +} + +static inline int poll_unblocked(snd_pcm_ioplug_t *io) +{ + static char buf[1]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + avail = snd_pcm_avail_update(io->pcm); + if (avail < 0 || avail >= jack->min_avail) + { + write(jack->fd, &buf, 1); + return 1; + } + + return 0; +} + static void snd_pcm_jack_free(snd_pcm_jack_t *jack) { if (jack) { @@ -81,14 +117,10 @@ static int snd_pcm_jack_poll_revents(snd_pcm_ioplug_t *io, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) { - static char buf[1]; - assert(pfds && nfds == 1 && revents);
- read(pfds[0].fd, buf, 1); - *revents = pfds[0].revents & ~(POLLIN | POLLOUT); - if (pfds[0].revents & POLLIN) + if (pfds[0].revents & POLLIN && !poll_blocked(io)) *revents |= (io->stream == SND_PCM_STREAM_PLAYBACK) ? POLLOUT : POLLIN; return 0; } @@ -105,7 +137,6 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_jack_t *jack = io->private_data; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0; - static char buf[1]; unsigned int channel; for (channel = 0; channel < io->channels; channel++) { @@ -145,7 +176,7 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) xfer += frames; }
- write(jack->fd, buf, 1); /* for polling */ + poll_unblocked(io); /* unblock socket for polling if needed */
return 0; } @@ -154,9 +185,25 @@ static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; unsigned int i; + snd_pcm_sw_params_t *swparams; + int err;
jack->hw_ptr = 0;
+ jack->min_avail = io->period_size; + snd_pcm_sw_params_alloca(&swparams); + err = snd_pcm_sw_params_current(io->pcm, swparams); + if (err == 0) { + snd_pcm_sw_params_get_avail_min(swparams, &jack->min_avail); + } + + poll_unblocked(io); /* unblock socket for initial polling if needed */ + + if (jack->activated) { + jack_deactivate(jack->client); + jack->activated = 0; + } + if (jack->ports) return 0;
--
At Fri, 02 May 2014 22:46:33 +0400, Sergey wrote:
Hello.
This patch fixes polling in alsa-to-jack plugin. It makes poll()+_poll_revents() return correct values whenever there's something to read/write.
Additionally jack_deactivate() code makes it survive snd_pcm_recover().
It works for the code example I posted before, aplay, arecord, mozilla, etc.
Comments and suggestions are welcome.
Thanks for the patch. The basic idea looks good, but some suggestions below.
diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 7a8b24d..a39fea5 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -42,6 +42,7 @@ typedef struct { unsigned int num_ports; unsigned int hw_ptr; unsigned int sample_bits;
snd_pcm_uframes_t min_avail;
unsigned int channels; snd_pcm_channel_area_t *areas;
@@ -50,6 +51,41 @@ typedef struct { jack_client_t *client; } snd_pcm_jack_t;
+static inline int poll_blocked(snd_pcm_ioplug_t *io)
You don't need inline in general. Compilers should be smart enough nowadays.
+{
- static char buf[65536];
- snd_pcm_sframes_t avail;
- snd_pcm_jack_t *jack = io->private_data;
- if (io->state == SND_PCM_STATE_RUNNING)
- {
Please follow the coding style in that file. The brace is placed in the same line as if ().
avail = snd_pcm_avail_update(io->pcm);if (avail >= 0 && avail < jack->min_avail){read(io->poll_fd, &buf, sizeof buf);
So, it's intended to clear all pending writes, right? If so, do reads in loop. Then you don't have to use such a big buffer. The size of 32 or such should be enough.
return 1;}- }
- return 0;
+}
+static inline int poll_unblocked(snd_pcm_ioplug_t *io)
The function names are a bit too ambiguous and hard to understand what they are really doing only from the names.
+{
- static char buf[1];
- snd_pcm_sframes_t avail;
- snd_pcm_jack_t *jack = io->private_data;
- avail = snd_pcm_avail_update(io->pcm);
- if (avail < 0 || avail >= jack->min_avail)
- {
write(jack->fd, &buf, 1);return 1;- }
- return 0;
+}
static void snd_pcm_jack_free(snd_pcm_jack_t *jack) { if (jack) { @@ -81,14 +117,10 @@ static int snd_pcm_jack_poll_revents(snd_pcm_ioplug_t *io, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) {
static char buf[1];
assert(pfds && nfds == 1 && revents);
read(pfds[0].fd, buf, 1);
*revents = pfds[0].revents & ~(POLLIN | POLLOUT);
if (pfds[0].revents & POLLIN)
- if (pfds[0].revents & POLLIN && !poll_blocked(io)) *revents |= (io->stream == SND_PCM_STREAM_PLAYBACK) ? POLLOUT : POLLIN; return 0;
} @@ -105,7 +137,6 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_jack_t *jack = io->private_data; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0;
static char buf[1]; unsigned int channel;
for (channel = 0; channel < io->channels; channel++) {
@@ -145,7 +176,7 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) xfer += frames; }
- write(jack->fd, buf, 1); /* for polling */
poll_unblocked(io); /* unblock socket for polling if needed */
return 0;
} @@ -154,9 +185,25 @@ static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; unsigned int i;
snd_pcm_sw_params_t *swparams;
int err;
jack->hw_ptr = 0;
jack->min_avail = io->period_size;
snd_pcm_sw_params_alloca(&swparams);
err = snd_pcm_sw_params_current(io->pcm, swparams);
if (err == 0) {
snd_pcm_sw_params_get_avail_min(swparams, &jack->min_avail);}
poll_unblocked(io); /* unblock socket for initial polling if needed */
Is this really needed?
- if (jack->activated) {
jack_deactivate(jack->client);jack->activated = 0;- }
This is same as just calling snd_pcm_jack_stop().
thanks,
Takashi
At Mon 05 May 2014 Takashi Iwai wrote:
This patch fixes polling in alsa-to-jack plugin. It makes poll()+_poll_revents() return correct values whenever there's something to read/write.
Additionally jack_deactivate() code makes it survive snd_pcm_recover().
It works for the code example I posted before, aplay, arecord, mozilla, etc.
Comments and suggestions are welcome.
Thanks for the patch. The basic idea looks good, but some suggestions below.
Thank you for your response and comments.
You don't need inline in general. Compilers should be smart enough nowadays.
Uninlined.
Please follow the coding style in that file. The brace is placed in the same line as if ().
Missed that, sorry. Fixed.
So, it's intended to clear all pending writes, right? If so, do reads in loop. Then you don't have to use such a big buffer. The size of 32 or such should be enough.
Done.
The function names are a bit too ambiguous and hard to understand what they are really doing only from the names.
How about pcm_poll_block() and pcm_poll_unblock()?
- poll_unblocked(io); /* unblock socket for initial polling if needed */
Is this really needed?
Playback pcm accepts writes since _prepare(), so poll() is unblocked there. Without it playback pcm gets poll() blocked by default and a code like: _open(); _set_params(); while (still_playing) { if (poll() > 0 && _revents() == 0 && revents&POLLOUT) _write(); } never starts writing.
- if (jack->activated) {
jack_deactivate(jack->client);jack->activated = 0;- }
This is same as just calling snd_pcm_jack_stop().
Right. To put snd_pcm_jack_stop() call in snd_pcm_jack_prepare() I have to move snd_pcm_jack_prepare() below snd_pcm_jack_stop(), that makes patch larger.
Patch updated and ready for more comments.
--- diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 7a8b24d..837e15c 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -42,6 +42,7 @@ typedef struct { unsigned int num_ports; unsigned int hw_ptr; unsigned int sample_bits; + snd_pcm_uframes_t min_avail;
unsigned int channels; snd_pcm_channel_area_t *areas; @@ -50,6 +51,38 @@ typedef struct { jack_client_t *client; } snd_pcm_jack_t;
+static int pcm_poll_block(snd_pcm_ioplug_t *io) +{ + static char buf[32]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + if (io->state == SND_PCM_STATE_RUNNING) { + avail = snd_pcm_avail_update(io->pcm); + if (avail >= 0 && avail < jack->min_avail) { + while (read(io->poll_fd, &buf, sizeof(buf)) == sizeof(buf)); + return 1; + } + } + + return 0; +} + +static int pcm_poll_unblock(snd_pcm_ioplug_t *io) +{ + static char buf[1]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + avail = snd_pcm_avail_update(io->pcm); + if (avail < 0 || avail >= jack->min_avail) { + write(jack->fd, &buf, 1); + return 1; + } + + return 0; +} + static void snd_pcm_jack_free(snd_pcm_jack_t *jack) { if (jack) { @@ -81,14 +114,10 @@ static int snd_pcm_jack_poll_revents(snd_pcm_ioplug_t *io, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) { - static char buf[1]; - assert(pfds && nfds == 1 && revents);
- read(pfds[0].fd, buf, 1); - *revents = pfds[0].revents & ~(POLLIN | POLLOUT); - if (pfds[0].revents & POLLIN) + if (pfds[0].revents & POLLIN && !pcm_poll_block(io)) *revents |= (io->stream == SND_PCM_STREAM_PLAYBACK) ? POLLOUT : POLLIN; return 0; } @@ -105,7 +134,6 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_jack_t *jack = io->private_data; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0; - static char buf[1]; unsigned int channel; for (channel = 0; channel < io->channels; channel++) { @@ -145,44 +173,11 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) xfer += frames; }
- write(jack->fd, buf, 1); /* for polling */ + pcm_poll_unblock(io); /* unblock socket for polling if needed */
return 0; }
-static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) -{ - snd_pcm_jack_t *jack = io->private_data; - unsigned int i; - - jack->hw_ptr = 0; - - if (jack->ports) - return 0; - - jack->ports = calloc(io->channels, sizeof(jack_port_t*)); - - for (i = 0; i < io->channels; i++) { - char port_name[32]; - if (io->stream == SND_PCM_STREAM_PLAYBACK) { - - sprintf(port_name, "out_%03d", i); - jack->ports[i] = jack_port_register(jack->client, port_name, - JACK_DEFAULT_AUDIO_TYPE, - JackPortIsOutput, 0); - } else { - sprintf(port_name, "in_%03d", i); - jack->ports[i] = jack_port_register(jack->client, port_name, - JACK_DEFAULT_AUDIO_TYPE, - JackPortIsInput, 0); - } - } - - jack_set_process_callback(jack->client, - (JackProcessCallback)snd_pcm_jack_process_cb, io); - return 0; -} - static int snd_pcm_jack_start(snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; @@ -233,6 +228,54 @@ static int snd_pcm_jack_stop(snd_pcm_ioplug_t *io) return 0; }
+static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) +{ + snd_pcm_jack_t *jack = io->private_data; + unsigned int i; + snd_pcm_sw_params_t *swparams; + int err; + + jack->hw_ptr = 0; + + jack->min_avail = io->period_size; + snd_pcm_sw_params_alloca(&swparams); + err = snd_pcm_sw_params_current(io->pcm, swparams); + if (err == 0) { + snd_pcm_sw_params_get_avail_min(swparams, &jack->min_avail); + } + + /* deactivate jack connections if this is XRUN recovery */ + snd_pcm_jack_stop(io); + + /* playback pcm initially accepts writes, poll must be unblocked */ + pcm_poll_unblock(io); + + if (jack->ports) + return 0; + + jack->ports = calloc(io->channels, sizeof(jack_port_t*)); + + for (i = 0; i < io->channels; i++) { + char port_name[32]; + if (io->stream == SND_PCM_STREAM_PLAYBACK) { + + sprintf(port_name, "out_%03d", i); + jack->ports[i] = jack_port_register(jack->client, port_name, + JACK_DEFAULT_AUDIO_TYPE, + JackPortIsOutput, 0); + } else { + sprintf(port_name, "in_%03d", i); + jack->ports[i] = jack_port_register(jack->client, port_name, + JACK_DEFAULT_AUDIO_TYPE, + JackPortIsInput, 0); + } + } + + jack_set_process_callback(jack->client, + (JackProcessCallback)snd_pcm_jack_process_cb, io); + return 0; +} + static snd_pcm_ioplug_callback_t jack_pcm_callback = { .close = snd_pcm_jack_close, .start = snd_pcm_jack_start, --
At Fri, 09 May 2014 04:00:50 +0400, Sergey wrote:
At Mon 05 May 2014 Takashi Iwai wrote:
This patch fixes polling in alsa-to-jack plugin. It makes poll()+_poll_revents() return correct values whenever there's something to read/write.
Additionally jack_deactivate() code makes it survive snd_pcm_recover().
It works for the code example I posted before, aplay, arecord, mozilla, etc.
Comments and suggestions are welcome.
Thanks for the patch. The basic idea looks good, but some suggestions below.
Thank you for your response and comments.
You don't need inline in general. Compilers should be smart enough nowadays.
Uninlined.
Please follow the coding style in that file. The brace is placed in the same line as if ().
Missed that, sorry. Fixed.
So, it's intended to clear all pending writes, right? If so, do reads in loop. Then you don't have to use such a big buffer. The size of 32 or such should be enough.
Done.
The function names are a bit too ambiguous and hard to understand what they are really doing only from the names.
How about pcm_poll_block() and pcm_poll_unblock()?
A bit better, but not really. You can give a comment to each function to explain what they do. Then you might find better names while explaining functionality to yourself.
- poll_unblocked(io); /* unblock socket for initial polling if needed */
Is this really needed?
Playback pcm accepts writes since _prepare(), so poll() is unblocked there. Without it playback pcm gets poll() blocked by default and a code like: _open(); _set_params(); while (still_playing) { if (poll() > 0 && _revents() == 0 && revents&POLLOUT) _write(); } never starts writing.
Then do it only for the playback. For capture, the poll shouldn't return at prepare state.
- if (jack->activated) {
jack_deactivate(jack->client);jack->activated = 0;- }
This is same as just calling snd_pcm_jack_stop().
Right. To put snd_pcm_jack_stop() call in snd_pcm_jack_prepare() I have to move snd_pcm_jack_prepare() below snd_pcm_jack_stop(), that makes patch larger.
You can declare a function.
thanks,
Takashi
Patch updated and ready for more comments.
diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 7a8b24d..837e15c 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -42,6 +42,7 @@ typedef struct { unsigned int num_ports; unsigned int hw_ptr; unsigned int sample_bits;
snd_pcm_uframes_t min_avail;
unsigned int channels; snd_pcm_channel_area_t *areas;
@@ -50,6 +51,38 @@ typedef struct { jack_client_t *client; } snd_pcm_jack_t;
+static int pcm_poll_block(snd_pcm_ioplug_t *io) +{
- static char buf[32];
- snd_pcm_sframes_t avail;
- snd_pcm_jack_t *jack = io->private_data;
- if (io->state == SND_PCM_STATE_RUNNING) {
avail = snd_pcm_avail_update(io->pcm);if (avail >= 0 && avail < jack->min_avail) {while (read(io->poll_fd, &buf, sizeof(buf)) == sizeof(buf));return 1;}- }
- return 0;
+}
+static int pcm_poll_unblock(snd_pcm_ioplug_t *io) +{
- static char buf[1];
- snd_pcm_sframes_t avail;
- snd_pcm_jack_t *jack = io->private_data;
- avail = snd_pcm_avail_update(io->pcm);
- if (avail < 0 || avail >= jack->min_avail) {
write(jack->fd, &buf, 1);return 1;- }
- return 0;
+}
static void snd_pcm_jack_free(snd_pcm_jack_t *jack) { if (jack) { @@ -81,14 +114,10 @@ static int snd_pcm_jack_poll_revents(snd_pcm_ioplug_t *io, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) {
static char buf[1];
assert(pfds && nfds == 1 && revents);
read(pfds[0].fd, buf, 1);
*revents = pfds[0].revents & ~(POLLIN | POLLOUT);
if (pfds[0].revents & POLLIN)
- if (pfds[0].revents & POLLIN && !pcm_poll_block(io)) *revents |= (io->stream == SND_PCM_STREAM_PLAYBACK) ? POLLOUT : POLLIN; return 0;
} @@ -105,7 +134,6 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_jack_t *jack = io->private_data; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0;
static char buf[1]; unsigned int channel;
for (channel = 0; channel < io->channels; channel++) {
@@ -145,44 +173,11 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) xfer += frames; }
- write(jack->fd, buf, 1); /* for polling */
pcm_poll_unblock(io); /* unblock socket for polling if needed */
return 0;
}
-static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) -{
- snd_pcm_jack_t *jack = io->private_data;
- unsigned int i;
- jack->hw_ptr = 0;
- if (jack->ports)
return 0;- jack->ports = calloc(io->channels, sizeof(jack_port_t*));
- for (i = 0; i < io->channels; i++) {
char port_name[32];if (io->stream == SND_PCM_STREAM_PLAYBACK) {sprintf(port_name, "out_%03d", i);jack->ports[i] = jack_port_register(jack->client, port_name,JACK_DEFAULT_AUDIO_TYPE,JackPortIsOutput, 0);} else {sprintf(port_name, "in_%03d", i);jack->ports[i] = jack_port_register(jack->client, port_name,JACK_DEFAULT_AUDIO_TYPE,JackPortIsInput, 0);}- }
- jack_set_process_callback(jack->client,
(JackProcessCallback)snd_pcm_jack_process_cb, io);- return 0;
-}
static int snd_pcm_jack_start(snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; @@ -233,6 +228,54 @@ static int snd_pcm_jack_stop(snd_pcm_ioplug_t *io) return 0; }
+static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) +{
- snd_pcm_jack_t *jack = io->private_data;
- unsigned int i;
- snd_pcm_sw_params_t *swparams;
- int err;
- jack->hw_ptr = 0;
- jack->min_avail = io->period_size;
- snd_pcm_sw_params_alloca(&swparams);
- err = snd_pcm_sw_params_current(io->pcm, swparams);
- if (err == 0) {
snd_pcm_sw_params_get_avail_min(swparams, &jack->min_avail);- }
- /* deactivate jack connections if this is XRUN recovery */
- snd_pcm_jack_stop(io);
- /* playback pcm initially accepts writes, poll must be unblocked */
- pcm_poll_unblock(io);
- if (jack->ports)
return 0;- jack->ports = calloc(io->channels, sizeof(jack_port_t*));
- for (i = 0; i < io->channels; i++) {
char port_name[32];if (io->stream == SND_PCM_STREAM_PLAYBACK) {sprintf(port_name, "out_%03d", i);jack->ports[i] = jack_port_register(jack->client, port_name,JACK_DEFAULT_AUDIO_TYPE,JackPortIsOutput, 0);} else {sprintf(port_name, "in_%03d", i);jack->ports[i] = jack_port_register(jack->client, port_name,JACK_DEFAULT_AUDIO_TYPE,JackPortIsInput, 0);}- }
- jack_set_process_callback(jack->client,
(JackProcessCallback)snd_pcm_jack_process_cb, io);- return 0;
+}
static snd_pcm_ioplug_callback_t jack_pcm_callback = { .close = snd_pcm_jack_close, .start = snd_pcm_jack_start, -- _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Fri 09 May 2014 Takashi Iwai wrote:
This patch fixes polling in alsa-to-jack plugin. It makes poll()+_poll_revents() return correct values whenever there's something to read/write.
Additionally jack_deactivate() code makes it survive snd_pcm_recover().
It works for the code example I posted before, aplay, arecord, mozilla, etc.
Comments and suggestions are welcome.
The function names are a bit too ambiguous and hard to understand what they are really doing only from the names.
How about pcm_poll_block() and pcm_poll_unblock()?
A bit better, but not really. You can give a comment to each function to explain what they do. Then you might find better names while explaining functionality to yourself.
pcm_poll_block() function blocks pcm polling if pcm is not ready to send data (capture pcm) or receive data (playback pcm). And pcm_poll_unblock() unblocks poll() if pcm is ready to send/receive data. But block_poll_if_pcm_not_ready() looks too cumbersome. Maybe pcm_poll_block_check() and pcm_poll_unblock_check()?
Playback pcm accepts writes since _prepare(), so poll() is unblocked there.
Then do it only for the playback. For capture, the poll shouldn't return at prepare state.
I thought that socket is created empty, so poll() is blocked by default. But you're right, I forgot about XRUN recovery, when _prepare() can be called with unblocked poll. It could be blocked by the next _poll_revents(), but it's probably better to have it explicitly blocked in _prepare(). I modified _block function and added its call to _prepare().
Right. To put snd_pcm_jack_stop() call in snd_pcm_jack_prepare() I have to move snd_pcm_jack_prepare() below snd_pcm_jack_stop(), that makes patch larger.
You can declare a function.
Done.
Patch updated.
--- diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 7a8b24d..36fbdc9 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -42,6 +42,7 @@ typedef struct { unsigned int num_ports; unsigned int hw_ptr; unsigned int sample_bits; + snd_pcm_uframes_t min_avail;
unsigned int channels; snd_pcm_channel_area_t *areas; @@ -50,6 +51,41 @@ typedef struct { jack_client_t *client; } snd_pcm_jack_t;
+static int snd_pcm_jack_stop(snd_pcm_ioplug_t *io); + +static int pcm_poll_block_check(snd_pcm_ioplug_t *io) +{ + static char buf[32]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + if (io->state == SND_PCM_STATE_RUNNING || + (io->state == SND_PCM_STATE_PREPARED && io->stream == SND_PCM_STREAM_CAPTURE)) { + avail = snd_pcm_avail_update(io->pcm); + if (avail >= 0 && avail < jack->min_avail) { + while (read(io->poll_fd, &buf, sizeof(buf)) == sizeof(buf)); + return 1; + } + } + + return 0; +} + +static int pcm_poll_unblock_check(snd_pcm_ioplug_t *io) +{ + static char buf[1]; + snd_pcm_sframes_t avail; + snd_pcm_jack_t *jack = io->private_data; + + avail = snd_pcm_avail_update(io->pcm); + if (avail < 0 || avail >= jack->min_avail) { + write(jack->fd, &buf, 1); + return 1; + } + + return 0; +} + static void snd_pcm_jack_free(snd_pcm_jack_t *jack) { if (jack) { @@ -81,14 +117,10 @@ static int snd_pcm_jack_poll_revents(snd_pcm_ioplug_t *io, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) { - static char buf[1]; - assert(pfds && nfds == 1 && revents);
- read(pfds[0].fd, buf, 1); - *revents = pfds[0].revents & ~(POLLIN | POLLOUT); - if (pfds[0].revents & POLLIN) + if (pfds[0].revents & POLLIN && !pcm_poll_block_check(io)) *revents |= (io->stream == SND_PCM_STREAM_PLAYBACK) ? POLLOUT : POLLIN; return 0; } @@ -105,7 +137,6 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_jack_t *jack = io->private_data; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0; - static char buf[1]; unsigned int channel; for (channel = 0; channel < io->channels; channel++) { @@ -145,7 +176,7 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) xfer += frames; }
- write(jack->fd, buf, 1); /* for polling */ + pcm_poll_unblock_check(io); /* unblock socket for polling if needed */
return 0; } @@ -154,9 +185,26 @@ static int snd_pcm_jack_prepare(snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; unsigned int i; + snd_pcm_sw_params_t *swparams; + int err;
jack->hw_ptr = 0;
+ jack->min_avail = io->period_size; + snd_pcm_sw_params_alloca(&swparams); + err = snd_pcm_sw_params_current(io->pcm, swparams); + if (err == 0) { + snd_pcm_sw_params_get_avail_min(swparams, &jack->min_avail); + } + + /* deactivate jack connections if this is XRUN recovery */ + snd_pcm_jack_stop(io); + + if (io->stream == SND_PCM_STREAM_PLAYBACK) + pcm_poll_unblock_check(io); /* playback pcm initially accepts writes */ + else + pcm_poll_block_check(io); /* block capture pcm if that's XRUN recovery */ + if (jack->ports) return 0;
--
participants (2)
-
Sergey -
Takashi Iwai