commit eab3e3a
Author: Mikhail Teterin <mi@aldan.algebra.com>
Date: Tue Dec 16 19:34:02 2014 -0800
Bug 1130155 - Avoid assert failures when consuming only part of buffer.
---
media/libcubeb/src/cubeb_alsa.c | 112 ++++++++++++++++++++++++++++++----------
1 file changed, 85 insertions(+), 27 deletions(-)
diff --git media/libcubeb/src/cubeb_alsa.c media/libcubeb/src/cubeb_alsa.c
index 9bbc129..e72944a 100644
--- media/libcubeb/src/cubeb_alsa.c
+++ media/libcubeb/src/cubeb_alsa.c
@@ -14,6 +14,8 @@
#include <limits.h>
#include <dlfcn.h>
#include <poll.h>
+#include <stdlib.h>
+#include <stdio.h>
#include <unistd.h>
#include <alsa/asoundlib.h>
#include "cubeb/cubeb.h"
@@ -45,6 +47,7 @@ MAKE_TYPEDEF(snd_pcm_avail_update);
MAKE_TYPEDEF(snd_pcm_close);
MAKE_TYPEDEF(snd_pcm_delay);
MAKE_TYPEDEF(snd_pcm_drain);
+MAKE_TYPEDEF(snd_pcm_forward);
MAKE_TYPEDEF(snd_pcm_frames_to_bytes);
MAKE_TYPEDEF(snd_pcm_get_params);
/* snd_pcm_hw_params_alloca is actually a macro */
@@ -305,32 +308,35 @@ alsa_refill_stream(cubeb_stream * stm)
long got;
void * p;
int draining;
+ unsigned pipefailures, againfailures;
draining = 0;
pthread_mutex_lock(&stm->mutex);
- r = WRAP(snd_pcm_poll_descriptors_revents)(stm->pcm, stm->fds, stm->nfds, &revents);
- if (r < 0 || revents != POLLOUT) {
- /* This should be a stream error; it makes no sense for poll(2) to wake
- for this stream and then have the stream report that it's not ready.
- Unfortunately, this does happen, so just bail out and try again. */
- pthread_mutex_unlock(&stm->mutex);
- return RUNNING;
- }
+ for (pipefailures = 0;;) {
+ r = WRAP(snd_pcm_poll_descriptors_revents)(stm->pcm, stm->fds, stm->nfds, &revents);
+ if (r < 0 || revents != POLLOUT ||
+ (avail = WRAP(snd_pcm_avail_update)(stm->pcm)) == 0) {
+ /* This should be a stream error; it makes no sense for poll(2) to wake
+ for this stream and then have the stream report that it's not ready.
+ Unfortunately, this does happen, so just bail out and try again. */
+ pthread_mutex_unlock(&stm->mutex);
+ return RUNNING;
+ }
- avail = WRAP(snd_pcm_avail_update)(stm->pcm);
- if (avail == -EPIPE) {
+ if (avail > 0)
+ break;
+ if (pipefailures++ > 11) {
+ fprintf(stderr, "%s: repeated failures from snd_pcm_avail_update, "
+ "giving up\n", __func__);
+ pthread_mutex_unlock(&stm->mutex);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ return ERROR;
+ }
WRAP(snd_pcm_recover)(stm->pcm, avail, 1);
- avail = WRAP(snd_pcm_avail_update)(stm->pcm);
- }
-
- /* Failed to recover from an xrun, this stream must be broken. */
- if (avail < 0) {
- pthread_mutex_unlock(&stm->mutex);
- stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
- return ERROR;
}
+ pipefailures = againfailures = 0;
/* This should never happen. */
if ((unsigned int) avail > stm->buffer_size) {
@@ -359,10 +365,11 @@ alsa_refill_stream(cubeb_stream * stm)
if (got < 0) {
pthread_mutex_unlock(&stm->mutex);
stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ free(p);
return ERROR;
}
if (got > 0) {
- snd_pcm_sframes_t wrote;
+ snd_pcm_sframes_t wrote, towrite = got;
if (stm->params.format == CUBEB_SAMPLE_FLOAT32NE) {
float * b = (float *) p;
@@ -375,14 +382,62 @@ alsa_refill_stream(cubeb_stream * stm)
b[i] *= stm->volume;
}
}
- wrote = WRAP(snd_pcm_writei)(stm->pcm, p, got);
- if (wrote == -EPIPE) {
- WRAP(snd_pcm_recover)(stm->pcm, wrote, 1);
- wrote = WRAP(snd_pcm_writei)(stm->pcm, p, got);
+ for (;;) {
+ wrote = WRAP(snd_pcm_writei)(stm->pcm, p,
+ towrite > avail ? avail : towrite);
+ switch(wrote) {
+ case -EPIPE:
+ if (pipefailures++ > 3) {
+ fprintf(stderr, "%s: Too many underflows, giving up\n", __func__);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ pthread_mutex_unlock(&stm->mutex);
+ free(p);
+ return ERROR;
+ }
+ WRAP(snd_pcm_recover)(stm->pcm, wrote, 1);
+ continue;
+ case -EAGAIN:
+ if (againfailures++ > 3) {
+ fprintf(stderr, "%s: Too many -EAGAIN errors from snd_pcm_writei, "
+ "giving up\n", __func__);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ pthread_mutex_unlock(&stm->mutex);
+ free(p);
+ return ERROR;
+ }
+ continue;
+ case -EBADFD:
+ fprintf(stderr, "%s: snc_pcm_writei returned -%s, giving up\n",
+ __func__, "EBADFD");
+ free(p);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ pthread_mutex_unlock(&stm->mutex);
+ return ERROR;
+ }
+ if (wrote < 0) {
+ fprintf(stderr, "%s: snc_pcm_writei returned unexpected error %lld, "
+ "giving up\n", __func__, (long long)wrote);
+ free(p);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ pthread_mutex_unlock(&stm->mutex);
+ return ERROR;
+ }
+ pipefailures = againfailures = 0;
+ stm->write_position += wrote;
+ gettimeofday(&stm->last_activity, NULL);
+ if (wrote > towrite) {
+ fprintf(stderr, "%s: snc_pcm_writei wrote %lld frames, which was more "
+ "than we requested (%lld). This should not happen, giving up\n",
+ __func__, (long long)wrote, (long long)towrite);
+ free(p);
+ stm->state_callback(stm, stm->user_ptr, CUBEB_STATE_ERROR);
+ pthread_mutex_unlock(&stm->mutex);
+ return ERROR;
+ }
+ if (towrite == wrote)
+ break;
+ towrite -= wrote;
}
- assert(wrote >= 0 && wrote == got);
- stm->write_position += wrote;
- gettimeofday(&stm->last_activity, NULL);
}
if (got != avail) {
long buffer_fill = stm->buffer_size - (avail - got);
@@ -1177,7 +1232,10 @@ alsa_stream_get_position(cubeb_stream * stm, uint64_t * position)
return CUBEB_OK;
}
- assert(delay >= 0);
+ if (delay < 0) {
+ WRAP(snd_pcm_forward)(stm->pcm, -delay);
+ delay = 0;
+ }
*position = 0;
if (stm->write_position >= (snd_pcm_uframes_t) delay) {