The rewrite of the thread function does not change functionality much, most of it is only cleanup, minor bug fixing and documentation work. This patch also changes the send buffer size for a2dp sink to avoid lags after temporary connection drops, following the proof-of-concept patch posted by Dmitry Kalyanov. Bug-Link: https://bugs.freedesktop.org/show_bug.cgi?id=58746 --- src/modules/bluetooth/module-bluez5-device.c | 271 ++++++++++++++++++--------- 1 file changed, 178 insertions(+), 93 deletions(-) diff --git a/src/modules/bluetooth/module-bluez5-device.c b/src/modules/bluetooth/module-bluez5-device.c index 7970dda7..7e5f8900 100644 --- a/src/modules/bluetooth/module-bluez5-device.c +++ b/src/modules/bluetooth/module-bluez5-device.c @@ -56,7 +56,6 @@ PA_MODULE_LOAD_ONCE(false); PA_MODULE_USAGE("path=<device object path>" "autodetect_mtu=<boolean>"); -#define MAX_PLAYBACK_CATCH_UP_USEC (100 * PA_USEC_PER_MSEC) #define FIXED_LATENCY_PLAYBACK_A2DP (25 * PA_USEC_PER_MSEC) #define FIXED_LATENCY_PLAYBACK_SCO (125 * PA_USEC_PER_MSEC) #define FIXED_LATENCY_RECORD_A2DP (25 * PA_USEC_PER_MSEC) @@ -660,6 +659,34 @@ static int a2dp_process_push(struct userdata *u) { return ret; } +static void update_buffer_size(struct userdata *u) { + int old_bufsize; + socklen_t len = sizeof(int); + int ret; + + ret = getsockopt(u->stream_fd, SOL_SOCKET, SO_SNDBUF, &old_bufsize, &len); + if (ret == -1) { + pa_log_warn("Changing bluetooth buffer size: Failed to getsockopt(SO_SNDBUF): %s", pa_cstrerror(errno)); + } else { + int new_bufsize; + + /* Set send buffer size as small as possible. The minimum value is 1024 according to the + * socket man page. The data is written to the socket in chunks of write_buffer_size, + * so there should at least be room for two chunks in the buffer. Generally, write_buf_size + * is larger than 512. If not, use the next multiple of write_block_size which is larger + * than 1024. */ + new_bufsize = 2 * u->write_block_size; + if (new_bufsize < 1024) + new_bufsize = (1024 / u->write_block_size + 1) * u->write_block_size; + + ret = setsockopt(u->stream_fd, SOL_SOCKET, SO_SNDBUF, &new_bufsize, len); + if (ret == -1) + pa_log_warn("Changing bluetooth buffer size: Failed to change from %d to %d: %s", old_bufsize, new_bufsize, pa_cstrerror(errno)); + else + pa_log_info("Changing bluetooth buffer size: Changed from %d to %d", old_bufsize, new_bufsize); + } +} + /* Run from I/O thread */ static void a2dp_set_bitpool(struct userdata *u, uint8_t bitpool) { struct sbc_info *sbc_info; @@ -694,6 +721,15 @@ static void a2dp_set_bitpool(struct userdata *u, uint8_t bitpool) { pa_sink_set_max_request_within_thread(u->sink, u->write_block_size); pa_sink_set_fixed_latency_within_thread(u->sink, FIXED_LATENCY_PLAYBACK_A2DP + pa_bytes_to_usec(u->write_block_size, &u->sample_spec)); + + /* If there is still data in the memchunk, we have to discard it + * because the write_block_size may have changed. */ + if (u->write_memchunk.memblock) { + pa_memblock_unref(u->write_memchunk.memblock); + pa_memchunk_reset(&u->write_memchunk); + } + + update_buffer_size(u); } /* Run from I/O thread */ @@ -852,8 +888,10 @@ static void setup_stream(struct userdata *u) { pa_log_debug("Stream properly set up, we're ready to roll!"); - if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) + if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) { a2dp_set_bitpool(u, u->sbc_info.max_bitpool); + update_buffer_size(u); + } u->rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1); pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL); @@ -861,7 +899,7 @@ static void setup_stream(struct userdata *u) { pollfd->events = pollfd->revents = 0; u->read_index = u->write_index = 0; - u->started_at = 0; + u->started_at = pa_rtclock_now(); u->stream_setup_done = true; if (u->source) @@ -1407,12 +1445,32 @@ static int init_profile(struct userdata *u) { return r; } +static int write_block(struct userdata *u) { + int n_written; + + if (u->write_index <= 0) + u->started_at = pa_rtclock_now(); + + if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) { + if ((n_written = a2dp_process_render(u)) < 0) + return -1; + } else { + if ((n_written = sco_process_render(u)) < 0) + return -1; + } + + if (n_written == 0) + pa_log("Got EAGAIN on write() after POLLOUT, probably there is a temporary connection loss."); + + return n_written; +} + + /* I/O thread function */ static void thread_func(void *userdata) { struct userdata *u = userdata; - unsigned do_write = 0; - unsigned pending_read_bytes = 0; - bool writable = false; + unsigned blocks_to_write = 0; + unsigned bytes_to_write = 0; pa_assert(u); pa_assert(u->transport); @@ -1432,9 +1490,13 @@ static void thread_func(void *userdata) { struct pollfd *pollfd; int ret; bool disable_timer = true; + bool writable = false; + bool have_source = u->source ? PA_SOURCE_IS_LINKED(u->source->thread_info.state) : false; + bool have_sink = u->sink ? PA_SINK_IS_LINKED(u->sink->thread_info.state) : false; pollfd = u->rtpoll_item ? pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL) : NULL; + /* Check for stream error or close */ if (pollfd && (pollfd->revents & ~(POLLOUT|POLLIN))) { pa_log_info("FD error: %s%s%s%s", pollfd->revents & POLLERR ? "POLLERR " :"", @@ -1445,147 +1507,170 @@ static void thread_func(void *userdata) { if (pollfd->revents & POLLHUP) { pollfd = NULL; teardown_stream(u); - do_write = 0; - pending_read_bytes = 0; + blocks_to_write = 0; + bytes_to_write = 0; writable = false; pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), BLUETOOTH_MESSAGE_STREAM_FD_HUP, NULL, 0, NULL, NULL); } else goto fail; } - if (u->source && PA_SOURCE_IS_LINKED(u->source->thread_info.state)) { + /* If there is a pollfd, the stream is set up and we need to do something */ + if (pollfd) { - /* We should send two blocks to the device before we expect - * a response. */ + /* Handle source if present */ + if (have_source) { - if (u->write_index == 0 && u->read_index <= 0) - do_write = 2; + /* We should send two blocks to the device before we expect a response. */ + if (u->write_index == 0 && u->read_index <= 0) + blocks_to_write = 2; - if (pollfd && (pollfd->revents & POLLIN)) { - int n_read; + /* If we got woken up by POLLIN let's do some reading */ + if (pollfd->revents & POLLIN) { + int n_read; - if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SOURCE) - n_read = a2dp_process_push(u); - else - n_read = sco_process_push(u); + if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SOURCE) + n_read = a2dp_process_push(u); + else + n_read = sco_process_push(u); - if (n_read < 0) - goto fail; + if (n_read < 0) + goto fail; - if (n_read > 0) { - /* We just read something, so we are supposed to write something, too */ - pending_read_bytes += n_read; - do_write += pending_read_bytes / u->write_block_size; - pending_read_bytes = pending_read_bytes % u->write_block_size; + if (n_read > 0) { + /* We just read something, so we are supposed to write something, too */ + bytes_to_write += n_read; + blocks_to_write += bytes_to_write / u->write_block_size; + bytes_to_write = bytes_to_write % u->write_block_size; + } } } - } - if (u->sink && PA_SINK_IS_LINKED(u->sink->thread_info.state)) { + /* Handle sink if present */ + if (have_sink) { - if (PA_UNLIKELY(u->sink->thread_info.rewind_requested)) - pa_sink_process_rewind(u->sink, 0); + /* Process rewinds */ + if (PA_UNLIKELY(u->sink->thread_info.rewind_requested)) + pa_sink_process_rewind(u->sink, 0); - if (pollfd) { + /* Test if the stream is writable */ if (pollfd->revents & POLLOUT) writable = true; - if ((!u->source || !PA_SOURCE_IS_LINKED(u->source->thread_info.state)) && do_write <= 0 && writable) { + /* If we have a source, we let the source determine the timing + * for the sink */ + if (have_source) { + + if (writable && blocks_to_write > 0) { + int result; + + if ((result = write_block(u)) < 0) + goto fail; + + blocks_to_write -= result; + writable = false; + } + + /* There is no source, we have to use the system clock for timing */ + } else { + bool have_written = false; pa_usec_t time_passed; pa_usec_t audio_sent; - /* Hmm, there is no input stream we could synchronize - * to. So let's do things by time */ - time_passed = pa_rtclock_now() - u->started_at; audio_sent = pa_bytes_to_usec(u->write_index, &u->sample_spec); + /* A new block needs to be sent. */ if (audio_sent <= time_passed) { - pa_usec_t audio_to_send = time_passed - audio_sent; + size_t bytes_to_send = pa_usec_to_bytes(time_passed - audio_sent, &u->sample_spec); - /* Never try to catch up for more than 100ms */ - if (u->write_index > 0 && audio_to_send > MAX_PLAYBACK_CATCH_UP_USEC) { - pa_usec_t skip_usec; + /* There are more than two blocks that need to be written. + * We cannot catch up, therefore discard everything older + * than two block sizes. */ + if (bytes_to_send > 2 * u->write_block_size) { uint64_t skip_bytes; + pa_memchunk tmp; + size_t mempool_max_block_size = pa_mempool_block_size_max(u->core->mempool); + pa_usec_t skip_usec; - skip_usec = audio_to_send - MAX_PLAYBACK_CATCH_UP_USEC; - skip_bytes = pa_usec_to_bytes(skip_usec, &u->sample_spec); + skip_bytes = bytes_to_send - 2 * u->write_block_size; + skip_usec = pa_bytes_to_usec(skip_bytes, &u->sample_spec); - if (skip_bytes > 0) { - pa_memchunk tmp; + pa_log_warn("Skipping %llu us (= %llu bytes) in audio stream", + (unsigned long long) skip_usec, + (unsigned long long) skip_bytes); - pa_log_warn("Skipping %llu us (= %llu bytes) in audio stream", - (unsigned long long) skip_usec, - (unsigned long long) skip_bytes); + while (skip_bytes > 0) { + size_t bytes_to_render; - pa_sink_render_full(u->sink, skip_bytes, &tmp); - pa_memblock_unref(tmp.memblock); - u->write_index += skip_bytes; + if (skip_bytes > mempool_max_block_size) + bytes_to_render = mempool_max_block_size; + else + bytes_to_render = skip_bytes; - if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) - a2dp_reduce_bitpool(u); + pa_sink_render_full(u->sink, bytes_to_render, &tmp); + pa_memblock_unref(tmp.memblock); + u->write_index += bytes_to_render; + skip_bytes -= bytes_to_render; } + + if (u->write_index > 0 && u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) + a2dp_reduce_bitpool(u); } - do_write = 1; - pending_read_bytes = 0; + blocks_to_write = 1; } - } - - if (writable && do_write > 0) { - int n_written; - if (u->write_index <= 0) - u->started_at = pa_rtclock_now(); + /* If the stream is writable, send some data if necessary */ + if (writable && blocks_to_write > 0) { + int result; - if (u->profile == PA_BLUETOOTH_PROFILE_A2DP_SINK) { - if ((n_written = a2dp_process_render(u)) < 0) - goto fail; - } else { - if ((n_written = sco_process_render(u)) < 0) + if ((result = write_block(u)) < 0) goto fail; - } - - if (n_written == 0) - pa_log("Broken kernel: we got EAGAIN on write() after POLLOUT!"); - do_write -= n_written; - writable = false; - } + blocks_to_write -= result; + writable = false; + have_written = true; + } - if ((!u->source || !PA_SOURCE_IS_LINKED(u->source->thread_info.state)) && do_write <= 0) { - pa_usec_t sleep_for; - pa_usec_t time_passed, next_write_at; - - if (writable) { - /* Hmm, there is no input stream we could synchronize - * to. So let's estimate when we need to wake up the latest */ - time_passed = pa_rtclock_now() - u->started_at; - next_write_at = pa_bytes_to_usec(u->write_index, &u->sample_spec); - sleep_for = time_passed < next_write_at ? next_write_at - time_passed : 0; - /* pa_log("Sleeping for %lu; time passed %lu, next write at %lu", (unsigned long) sleep_for, (unsigned long) time_passed, (unsigned long)next_write_at); */ - } else - /* drop stream every 500 ms */ - sleep_for = PA_USEC_PER_MSEC * 500; - - pa_rtpoll_set_timer_relative(u->rtpoll, sleep_for); - disable_timer = false; + /* If nothing was written during this iteration, either the stream + * is not writable or there was no write pending. Set up a timer that + * will wake up the thread when the next data needs to be written. */ + if (!have_written) { + pa_usec_t sleep_for; + pa_usec_t next_write_at; + + if (writable) { + /* There was no write pending on this iteration of the loop. + * Let's estimate when we need to wake up next */ + next_write_at = pa_bytes_to_usec(u->write_index, &u->sample_spec); + sleep_for = time_passed < next_write_at ? next_write_at - time_passed : 0; + /* pa_log("Sleeping for %lu; time passed %lu, next write at %lu", (unsigned long) sleep_for, (unsigned long) time_passed, (unsigned long)next_write_at); */ + } else + /* We could not write because the stream was not ready. Let's try + * again in 500 ms and drop audio if we still can't write. The + * thread will also be woken up when we can write again. */ + sleep_for = PA_USEC_PER_MSEC * 500; + + pa_rtpoll_set_timer_relative(u->rtpoll, sleep_for); + disable_timer = false; + } } } + + /* Set events to wake up the thread */ + pollfd->events = (short) (((have_sink && !writable) ? POLLOUT : 0) | (have_source ? POLLIN : 0)); + } if (disable_timer) pa_rtpoll_set_timer_disabled(u->rtpoll); - /* Hmm, nothing to do. Let's sleep */ - if (pollfd) - pollfd->events = (short) (((u->sink && PA_SINK_IS_LINKED(u->sink->thread_info.state) && !writable) ? POLLOUT : 0) | - (u->source && PA_SOURCE_IS_LINKED(u->source->thread_info.state) ? POLLIN : 0)); - if ((ret = pa_rtpoll_run(u->rtpoll)) < 0) { pa_log_debug("pa_rtpoll_run failed with: %d", ret); goto fail; } + if (ret == 0) { pa_log_debug("IO thread shutdown requested, stopping cleanly"); transport_release(u); -- 2.14.1
