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uridownloader: Simplify locking to fix deadlocks

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Use object lock to protect variables from concurrent access and
use download_lock to only allow one download running
This commit is contained in:
Thiago Santos 2013-07-02 23:16:59 -03:00
parent 0a88daaf8e
commit cd26bd51a1
1 changed files with 26 additions and 24 deletions
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50
gst-libs/gst/uridownloader/gsturidownloader.c
View file

@ -39,7 +39,8 @@ struct _GstUriDownloaderPrivate
GstPad *pad;
GTimeVal *timeout;
GstFragment *download;
GMutex lock;
GMutex download_lock; /* used to restrict to one download only */
GCond cond;
gboolean cancelled;
};
@ -99,7 +100,7 @@ gst_uri_downloader_init (GstUriDownloader * downloader)
/* Create a bus to handle error and warning message from the source element */
downloader->priv->bus = gst_bus_new ();
g_mutex_init (&downloader->priv->lock);
g_mutex_init (&downloader->priv->download_lock);
g_cond_init (&downloader->priv->cond);
}
@ -136,7 +137,7 @@ gst_uri_downloader_finalize (GObject * object)
{
GstUriDownloader *downloader = GST_URI_DOWNLOADER (object);
g_mutex_clear (&downloader->priv->lock);
g_mutex_clear (&downloader->priv->download_lock);
g_cond_clear (&downloader->priv->cond);
G_OBJECT_CLASS (gst_uri_downloader_parent_class)->finalize (object);
@ -166,14 +167,10 @@ gst_uri_downloader_sink_event (GstPad * pad, GstObject * parent,
downloader->priv->download->completed = TRUE;
downloader->priv->download->download_stop_time =
gst_util_get_timestamp ();
GST_OBJECT_UNLOCK (downloader);
GST_DEBUG_OBJECT (downloader, "Signaling chain funtion");
g_mutex_lock (&downloader->priv->lock);
g_cond_signal (&downloader->priv->cond);
g_mutex_unlock (&downloader->priv->lock);
} else {
GST_OBJECT_UNLOCK (downloader);
}
GST_OBJECT_UNLOCK (downloader);
gst_event_unref (event);
break;
}
@ -267,21 +264,15 @@ gst_uri_downloader_stop (GstUriDownloader * downloader)
urisrc = downloader->priv->urisrc;
downloader->priv->urisrc = NULL;
/* unlock so it doesn't block on chain function while changing state */
g_mutex_unlock (&downloader->priv->lock);
GST_DEBUG_OBJECT (downloader, "Stopping source element %s",
GST_ELEMENT_NAME (urisrc));
/* set the element state to NULL */
gst_bus_set_flushing (downloader->priv->bus, TRUE);
gst_element_set_state (urisrc, GST_STATE_NULL);
gst_element_get_state (urisrc, NULL, NULL, GST_CLOCK_TIME_NONE);
gst_element_set_bus (urisrc, NULL);
gst_object_unref (urisrc);
/* caller expects the mutex to be locked */
g_mutex_lock (&downloader->priv->lock);
gst_bus_set_flushing (downloader->priv->bus, TRUE);
}
void
@ -303,21 +294,18 @@ gst_uri_downloader_cancel (GstUriDownloader * downloader)
g_object_unref (downloader->priv->download);
downloader->priv->download = NULL;
downloader->priv->cancelled = TRUE;
GST_OBJECT_UNLOCK (downloader);
GST_DEBUG_OBJECT (downloader, "Signaling chain funtion");
g_mutex_lock (&downloader->priv->lock);
g_cond_signal (&downloader->priv->cond);
g_mutex_unlock (&downloader->priv->lock);
} else {
gboolean cancelled;
cancelled = downloader->priv->cancelled;
downloader->priv->cancelled = TRUE;
GST_OBJECT_UNLOCK (downloader);
if (cancelled)
GST_DEBUG_OBJECT (downloader,
"Trying to cancell a download that was alredy cancelled");
}
GST_OBJECT_UNLOCK (downloader);
}
static gboolean
@ -390,8 +378,9 @@ gst_uri_downloader_fetch_uri_with_range (GstUriDownloader * downloader,
GstStateChangeReturn ret;
GstFragment *download = NULL;
g_mutex_lock (&downloader->priv->lock);
g_mutex_lock (&downloader->priv->download_lock);
GST_OBJECT_LOCK (downloader);
if (downloader->priv->cancelled) {
goto quit;
}
@ -402,31 +391,45 @@ gst_uri_downloader_fetch_uri_with_range (GstUriDownloader * downloader,
}
gst_bus_set_flushing (downloader->priv->bus, FALSE);
GST_OBJECT_UNLOCK (downloader);
ret = gst_element_set_state (downloader->priv->urisrc, GST_STATE_READY);
GST_OBJECT_LOCK (downloader);
if (ret == GST_STATE_CHANGE_FAILURE) {
goto quit;
}
/* might have been cancelled because of failures in state change */
if (downloader->priv->cancelled) {
goto quit;
}
if (!gst_uri_downloader_set_range (downloader, range_start, range_end)) {
GST_WARNING_OBJECT (downloader, "Failed to set range");
goto quit;
}
downloader->priv->download = gst_fragment_new ();
GST_OBJECT_UNLOCK (downloader);
ret = gst_element_set_state (downloader->priv->urisrc, GST_STATE_PLAYING);
GST_OBJECT_LOCK (downloader);
if (ret == GST_STATE_CHANGE_FAILURE) {
g_object_unref (downloader->priv->download);
downloader->priv->download = NULL;
goto quit;
}
/* might have been cancelled because of failures in state change */
if (downloader->priv->cancelled) {
goto quit;
}
/* wait until:
* - the download succeed (EOS in the src pad)
* - the download failed (Error message on the fetcher bus)
* - the download was canceled
*/
GST_DEBUG_OBJECT (downloader, "Waiting to fetch the URI %s", uri);
g_cond_wait (&downloader->priv->cond, &downloader->priv->lock);
g_cond_wait (&downloader->priv->cond, GST_OBJECT_GET_LOCK (downloader));
if (downloader->priv->cancelled) {
if (downloader->priv->download) {
@ -436,10 +439,8 @@ gst_uri_downloader_fetch_uri_with_range (GstUriDownloader * downloader,
goto quit;
}
GST_OBJECT_LOCK (downloader);
download = downloader->priv->download;
downloader->priv->download = NULL;
GST_OBJECT_UNLOCK (downloader);
if (download != NULL)
GST_INFO_OBJECT (downloader, "URI fetched successfully");
@ -449,7 +450,8 @@ gst_uri_downloader_fetch_uri_with_range (GstUriDownloader * downloader,
quit:
{
gst_uri_downloader_stop (downloader);
g_mutex_unlock (&downloader->priv->lock);
GST_OBJECT_UNLOCK (downloader);
g_mutex_unlock (&downloader->priv->download_lock);
return download;
}
}