Commit 50d7d0c9 authored by Avishay Spitzer's avatar Avishay Spitzer Committed by Ilkka Ollakka
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Bug fix: HLS module does not block until data is available. As a result live...


Bug fix: HLS module does not block until data is available. As a result live streams may end unexpectedly in case of short playlists or slow connections. Problem was fixed by blocking on a condition variable in the "read" function in case data is not available until Download thread signals (when new data is available) or a timeout of 10 seconds is reached. Blocking is done with a timed wait in order to avoid deadlocks since the thread that calls read is also responsible for calling close.
Signed-off-by: Ilkka Ollakka's avatarIlkka Ollakka <ileoo@videolan.org>
parent a9498add
......@@ -135,6 +135,12 @@ struct stream_sys_t
int tries; /* times it was not changed */
} playlist;
struct hls_read_s
{
vlc_mutex_t lock_wait; /* used by read condition variable */
vlc_cond_t wait; /* some condition to wait on during read */
} read;
/* state */
bool b_cache; /* can cache files */
bool b_meta; /* meta playlist */
......@@ -1672,6 +1678,11 @@ static void* hls_Thread(void *p_this)
p_sys->download.segment++;
vlc_cond_signal(&p_sys->download.wait);
vlc_mutex_unlock(&p_sys->download.lock_wait);
// In case of a successful download signal the read thread that data is available
vlc_mutex_lock(&p_sys->read.lock_wait);
vlc_cond_signal(&p_sys->read.wait);
vlc_mutex_unlock(&p_sys->read.lock_wait);
}
vlc_restorecancel(canc);
......@@ -2029,6 +2040,9 @@ static int Open(vlc_object_t *p_this)
vlc_mutex_init(&p_sys->download.lock_wait);
vlc_cond_init(&p_sys->download.wait);
vlc_mutex_init(&p_sys->read.lock_wait);
vlc_cond_init(&p_sys->read.wait);
/* Initialize HLS live stream */
if (p_sys->b_live)
{
......@@ -2056,6 +2070,9 @@ fail_thread:
vlc_mutex_destroy(&p_sys->download.lock_wait);
vlc_cond_destroy(&p_sys->download.wait);
vlc_mutex_destroy(&p_sys->read.lock_wait);
vlc_cond_destroy(&p_sys->read.wait);
fail:
/* Free hls streams */
for (int i = 0; i < vlc_array_count(p_sys->hls_stream); i++)
......@@ -2096,6 +2113,9 @@ static void Close(vlc_object_t *p_this)
vlc_mutex_destroy(&p_sys->download.lock_wait);
vlc_cond_destroy(&p_sys->download.wait);
vlc_mutex_destroy(&p_sys->read.lock_wait);
vlc_cond_destroy(&p_sys->read.wait);
/* Free hls streams */
for (int i = 0; i < vlc_array_count(p_sys->hls_stream); i++)
{
......@@ -2284,13 +2304,55 @@ static int Read(stream_t *s, void *buffer, unsigned int i_read)
assert(p_sys->hls_stream);
if (p_sys->b_error)
return 0;
while (length == 0)
{
// In case an error occurred or the stream was closed return 0
if (p_sys->b_error || !vlc_object_alive(s))
return 0;
/* NOTE: buffer might be NULL if caller wants to skip data */
length = hls_Read(s, (uint8_t*) buffer, i_read);
if (length < 0)
return 0;
// Lock the mutex before trying to read to avoid a race condition with the download thread
vlc_mutex_lock(&p_sys->read.lock_wait);
/* NOTE: buffer might be NULL if caller wants to skip data */
length = hls_Read(s, (uint8_t*) buffer, i_read);
// An error has occurred in hls_Read
if (length < 0)
{
vlc_mutex_unlock(&p_sys->read.lock_wait);
return 0;
}
// There is no data available yet for the demuxer so we need to wait until reload and
// download operation are over.
// Download thread will signal once download is finished.
// A timed wait is used to avoid deadlock in case data never arrives since the thread
// running this read operation is also responsible for closing the stream
if (length == 0)
{
mtime_t start = mdate();
// Wait for 10 seconds
mtime_t timeout_limit = start + (10 * UINT64_C(1000000));
int res = vlc_cond_timedwait(&p_sys->read.wait, &p_sys->read.lock_wait, timeout_limit);
// Error - reached a timeout of 10 seconds without data arriving - kill the stream
if (res == ETIMEDOUT)
{
msg_Info(s, "timeout limit reached!");
vlc_mutex_unlock(&p_sys->read.lock_wait);
return 0;
}
else if (res == EINVAL)
return 0; // Error - lock is not locked so we can just return
}
vlc_mutex_unlock(&p_sys->read.lock_wait);
}
p_sys->playback.offset += length;
return length;
......
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