diff options
| author | Robin Gareus <robin@gareus.org> | 2017-04-09 04:04:57 +0200 |
|---|---|---|
| committer | Robin Gareus <robin@gareus.org> | 2017-04-09 05:03:19 +0200 |
| commit | 6968c9f909f429d3c79c5540df2a76fbc7054e31 (patch) | |
| tree | 2859cb44db04b5ac77bd5a640616601bcc8d73da /libs/backends | |
| parent | 65ff43d0a73bb0b08b9942932ece97edd79bc714 (diff) | |
Drain ALSA raw-midi buffers after 64 bytes
Very long sequence of *concurrent* events may otherwise be truncated
because the backend requests a buffer-size of 64 bytes via
snd_rawmidi_params_set_buffer_size().
Diffstat (limited to 'libs/backends')
| -rw-r--r-- | libs/backends/alsa/alsa_rawmidi.cc | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/libs/backends/alsa/alsa_rawmidi.cc b/libs/backends/alsa/alsa_rawmidi.cc index 0702c63158..8d2420a6cb 100644 --- a/libs/backends/alsa/alsa_rawmidi.cc +++ b/libs/backends/alsa/alsa_rawmidi.cc @@ -88,7 +88,7 @@ AlsaRawMidiIO::init (const char *device_name, const bool input) if (snd_rawmidi_params_set_avail_min (_device, params, 1)) { goto initerr; } - if ( snd_rawmidi_params_set_buffer_size (_device, params, 64)) { + if (snd_rawmidi_params_set_buffer_size (_device, params, 64)) { goto initerr; } if (snd_rawmidi_params_set_no_active_sensing (_device, params, 1)) { @@ -119,7 +119,7 @@ AlsaRawMidiOut::main_process_thread () { _running = true; pthread_mutex_lock (&_notify_mutex); - bool need_drain = false; + unsigned int need_drain = 0; while (_running) { bool have_data = false; struct MidiEventHeader h(0,0); @@ -146,9 +146,9 @@ AlsaRawMidiOut::main_process_thread () } if (!have_data) { - if (need_drain) { + if (need_drain > 0) { snd_rawmidi_drain (_device); - need_drain = false; + need_drain = 0; } pthread_cond_wait (&_notify_ready, &_notify_mutex); continue; @@ -156,9 +156,9 @@ AlsaRawMidiOut::main_process_thread () uint64_t now = g_get_monotonic_time(); while (h.time > now + 500) { - if (need_drain) { + if (need_drain > 0) { snd_rawmidi_drain (_device); - need_drain = false; + need_drain = 0; } else { select_sleep(h.time - now); } @@ -195,6 +195,14 @@ retry: ssize_t err = snd_rawmidi_write (_device, data, h.size); +#if 0 // DEBUG -- not rt-safe + printf("TX [%ld | %ld]", h.size, err); + for (size_t i = 0; i < h.size; ++i) { + printf (" %02x", data[i]); + } + printf ("\n"); +#endif + if ((err == -EAGAIN)) { snd_rawmidi_drain (_device); goto retry; @@ -213,7 +221,11 @@ retry: h.size -= err; goto retry; } - need_drain = true; + + if ((need_drain += h.size) >= 64) { + snd_rawmidi_drain (_device); + need_drain = 0; + } } pthread_mutex_unlock (&_notify_mutex); |