1*4882a593SmuzhiyunFrom ef206e6b67526e9fc91f9515a1a1b65a5e755f14 Mon Sep 17 00:00:00 2001
2*4882a593SmuzhiyunFrom: Jeffy Chen <jeffy.chen@rock-chips.com>
3*4882a593SmuzhiyunDate: Fri, 26 Nov 2021 17:41:47 +0800
4*4882a593SmuzhiyunSubject: [PATCH 04/14] playbin2: Fix deadlock when hooking about-to-finish
5*4882a593Smuzhiyun signal
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunThe playbin2 will deactivate old group in drain_cb() for that, which
8*4882a593Smuzhiyunwould cause deadlock when other thread tries to notify pad-change at
9*4882a593Smuzhiyunthe same time.
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunSigned-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
12*4882a593Smuzhiyun---
13*4882a593Smuzhiyun gst/playback/gstplaybin2.c | 21 +++++++++++++++++++++
14*4882a593Smuzhiyun 1 file changed, 21 insertions(+)
15*4882a593Smuzhiyun
16*4882a593Smuzhiyundiff --git a/gst/playback/gstplaybin2.c b/gst/playback/gstplaybin2.c
17*4882a593Smuzhiyunindex 4098fb9..cbd8e08 100644
18*4882a593Smuzhiyun--- a/gst/playback/gstplaybin2.c
19*4882a593Smuzhiyun+++ b/gst/playback/gstplaybin2.c
20*4882a593Smuzhiyun@@ -389,6 +389,11 @@ G_STMT_START {                                          \
21*4882a593Smuzhiyun #define GST_PLAY_BIN_SHUTDOWN_UNLOCK(bin)         \
22*4882a593Smuzhiyun   GST_PLAY_BIN_DYN_UNLOCK (bin);                  \
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun+/* lock to protect drain callbacks */
25*4882a593Smuzhiyun+#define GST_PLAY_BIN_DRAIN_LOCK(bin)    g_mutex_lock (&(bin)->drain_lock)
26*4882a593Smuzhiyun+#define GST_PLAY_BIN_DRAIN_TRYLOCK(bin)    g_mutex_trylock (&(bin)->drain_lock)
27*4882a593Smuzhiyun+#define GST_PLAY_BIN_DRAIN_UNLOCK(bin)  g_mutex_unlock (&(bin)->drain_lock)
28*4882a593Smuzhiyun+
29*4882a593Smuzhiyun /**
30*4882a593Smuzhiyun  * GstPlayBin:
31*4882a593Smuzhiyun  *
32*4882a593Smuzhiyun@@ -431,6 +436,9 @@ struct _GstPlayBin
33*4882a593Smuzhiyun   gint shutdown;
34*4882a593Smuzhiyun   gboolean async_pending;       /* async-start has been emitted */
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun+  /* lock protecting draining */
37*4882a593Smuzhiyun+  GMutex drain_lock;
38*4882a593Smuzhiyun+
39*4882a593Smuzhiyun   GMutex elements_lock;
40*4882a593Smuzhiyun   guint32 elements_cookie;
41*4882a593Smuzhiyun   GList *elements;              /* factories we can use for selecting elements */
42*4882a593Smuzhiyun@@ -1537,6 +1545,7 @@ gst_play_bin_init (GstPlayBin * playbin)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun   g_rec_mutex_init (&playbin->lock);
45*4882a593Smuzhiyun   g_mutex_init (&playbin->dyn_lock);
46*4882a593Smuzhiyun+  g_mutex_init (&playbin->drain_lock);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun   /* assume we can create an input-selector */
49*4882a593Smuzhiyun   playbin->have_selector = TRUE;
50*4882a593Smuzhiyun@@ -1633,6 +1642,7 @@ gst_play_bin_finalize (GObject * object)
51*4882a593Smuzhiyun   g_list_free_full (playbin->contexts, (GDestroyNotify) gst_context_unref);
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun   g_rec_mutex_clear (&playbin->lock);
54*4882a593Smuzhiyun+  g_mutex_clear (&playbin->drain_lock);
55*4882a593Smuzhiyun   g_mutex_clear (&playbin->dyn_lock);
56*4882a593Smuzhiyun   g_mutex_clear (&playbin->elements_lock);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun@@ -3112,7 +3122,14 @@ combiner_active_pad_changed (GObject * combiner, GParamSpec * pspec,
59*4882a593Smuzhiyun   GstSourceCombine *combine = NULL;
60*4882a593Smuzhiyun   int i;
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun+  /* We got a pad-change after draining; no need to notify */
63*4882a593Smuzhiyun+  if (!GST_PLAY_BIN_DRAIN_TRYLOCK (playbin))
64*4882a593Smuzhiyun+    return;
65*4882a593Smuzhiyun+
66*4882a593Smuzhiyun   GST_PLAY_BIN_LOCK (playbin);
67*4882a593Smuzhiyun+
68*4882a593Smuzhiyun+  GST_PLAY_BIN_DRAIN_UNLOCK (playbin);
69*4882a593Smuzhiyun+
70*4882a593Smuzhiyun   group = get_group (playbin);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun   for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
73*4882a593Smuzhiyun@@ -3929,7 +3946,11 @@ drained_cb (GstElement * decodebin, GstSourceGroup * group)
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun   /* now activate the next group. If the app did not set a uri, this will
76*4882a593Smuzhiyun    * fail and we can do EOS */
77*4882a593Smuzhiyun+
78*4882a593Smuzhiyun+  GST_PLAY_BIN_DRAIN_LOCK (playbin);
79*4882a593Smuzhiyun   setup_next_source (playbin, GST_STATE_PAUSED);
80*4882a593Smuzhiyun+  GST_PLAY_BIN_DRAIN_UNLOCK (playbin);
81*4882a593Smuzhiyun+
82*4882a593Smuzhiyun   group->pending_about_to_finish = TRUE;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun--
86*4882a593Smuzhiyun2.20.1
87*4882a593Smuzhiyun
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