tracing: add hooks for gst_pad_chain() / gst_pad_chain_list()

This allows tracing buffers when they arrive in a pad instead of just
when they are pushed out of a pad.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2682>

subprojects/gstreamer/gst/gstpad.c

@@ -4390,6 +4390,12 @@ gst_pad_chain_data_unchecked (GstPad * pad, GstPadProbeType type, void *data)
   GstObject *parent;
   gboolean handled = FALSE;
 
+  if (type & GST_PAD_PROBE_TYPE_BUFFER_LIST) {
+    GST_TRACER_PAD_CHAIN_LIST_PRE (pad, data);
+  } else {
+    GST_TRACER_PAD_CHAIN_PRE (pad, data);
+  }
+
   GST_PAD_STREAM_LOCK (pad);
 
   GST_OBJECT_LOCK (pad);
@@ -4469,6 +4475,13 @@ gst_pad_chain_data_unchecked (GstPad * pad, GstPadProbeType type, void *data)
 
   GST_PAD_STREAM_UNLOCK (pad);
 
+out:
+  if (type & GST_PAD_PROBE_TYPE_BUFFER_LIST) {
+    GST_TRACER_PAD_CHAIN_LIST_POST (pad, ret);
+  } else {
+    GST_TRACER_PAD_CHAIN_POST (pad, ret);
+  }
+
   return ret;
 
   /* ERRORS */
@@ -4480,7 +4493,8 @@ flushing:
     GST_OBJECT_UNLOCK (pad);
     GST_PAD_STREAM_UNLOCK (pad);
     gst_mini_object_unref (GST_MINI_OBJECT_CAST (data));
-    return GST_FLOW_FLUSHING;
+    ret = GST_FLOW_FLUSHING;
+    goto out;
   }
 eos:
   {
@@ -4489,7 +4503,8 @@ eos:
     GST_OBJECT_UNLOCK (pad);
     GST_PAD_STREAM_UNLOCK (pad);
     gst_mini_object_unref (GST_MINI_OBJECT_CAST (data));
-    return GST_FLOW_EOS;
+    ret = GST_FLOW_EOS;
+    goto out;
   }
 wrong_mode:
   {
@@ -4499,7 +4514,8 @@ wrong_mode:
     GST_OBJECT_UNLOCK (pad);
     GST_PAD_STREAM_UNLOCK (pad);
     gst_mini_object_unref (GST_MINI_OBJECT_CAST (data));
-    return GST_FLOW_ERROR;
+    ret = GST_FLOW_ERROR;
+    goto out;
   }
 probe_handled:
   handled = TRUE;
@@ -4523,7 +4539,7 @@ probe_stopped:
     pad->ABI.abi.last_flowret = ret;
     GST_OBJECT_UNLOCK (pad);
     GST_PAD_STREAM_UNLOCK (pad);
-    return ret;
+    goto out;
   }
 no_parent:
   {
@@ -4532,7 +4548,8 @@ no_parent:
     gst_mini_object_unref (GST_MINI_OBJECT_CAST (data));
     GST_OBJECT_UNLOCK (pad);
     GST_PAD_STREAM_UNLOCK (pad);
-    return GST_FLOW_FLUSHING;
+    ret = GST_FLOW_FLUSHING;
+    goto out;
   }
 no_function:
   {
@@ -4542,7 +4559,8 @@ no_function:
     g_critical ("chain on pad %s:%s but it has no chainfunction",
         GST_DEBUG_PAD_NAME (pad));
     GST_PAD_STREAM_UNLOCK (pad);
-    return GST_FLOW_NOT_SUPPORTED;
+    ret = GST_FLOW_NOT_SUPPORTED;
+    goto out;
   }
 }
 

subprojects/gstreamer/gst/gsttracerutils.c

@@ -54,7 +54,9 @@ static const gchar *_quark_strings[] = {
   "element-change-state-pre", "element-change-state-post",
   "mini-object-created", "mini-object-destroyed", "object-created",
   "object-destroyed", "mini-object-reffed", "mini-object-unreffed",
-  "object-reffed", "object-unreffed", "plugin-feature-loaded"
+  "object-reffed", "object-unreffed", "plugin-feature-loaded",
+  "pad-chain-pre", "pad-chain-post", "pad-chain-list-pre",
+  "pad-chain-list-post",
 };
 
 GQuark _priv_gst_tracer_quark_table[GST_TRACER_QUARK_MAX];

subprojects/gstreamer/gst/gsttracerutils.h

@@ -80,6 +80,10 @@ typedef enum /*< skip >*/
   GST_TRACER_QUARK_HOOK_OBJECT_REFFED,
   GST_TRACER_QUARK_HOOK_OBJECT_UNREFFED,
   GST_TRACER_QUARK_HOOK_PLUGIN_FEATURE_LOADED,
+  GST_TRACER_QUARK_HOOK_PAD_CHAIN_PRE,
+  GST_TRACER_QUARK_HOOK_PAD_CHAIN_POST,
+  GST_TRACER_QUARK_HOOK_PAD_CHAIN_LIST_PRE,
+  GST_TRACER_QUARK_HOOK_PAD_CHAIN_LIST_POST,
   GST_TRACER_QUARK_MAX
 } GstTracerQuarkId;
 
@@ -722,6 +726,118 @@ typedef void (*GstTracerHookPluginFeatureLoaded) (GObject *self, GstClockTime ts
     GstTracerHookPluginFeatureLoaded, (GST_TRACER_ARGS, feature)); \
 }G_STMT_END
 
+/**
+ * GstTracerHookPadChainPre:
+ * @self: the tracer instance
+ * @ts: the current timestamp
+ * @pad: the pad
+ * @buffer: the buffer
+ *
+ * Pre-hook for gst_pad_chain() named "pad-chain-pre".
+ *
+ * Since: 1.22
+ */
+typedef void (*GstTracerHookPadChainPre) (GObject *self, GstClockTime ts,
+    GstPad *pad, GstBuffer *buffer);
+
+/**
+ * GST_TRACER_PAD_CHAIN_PRE:
+ * @pad: a %GstPad
+ * @buffer: a %GstBuffer
+ *
+ * Dispatches the "pad-chain-pre" hook.
+ *
+ * Since: 1.22
+ */
+#define GST_TRACER_PAD_CHAIN_PRE(pad, buffer) G_STMT_START{ \
+  GST_TRACER_DISPATCH(GST_TRACER_QUARK(HOOK_PAD_CHAIN_PRE), \
+    GstTracerHookPadChainPre, (GST_TRACER_ARGS, pad, buffer)); \
+}G_STMT_END
+
+/**
+ * GstTracerHookPadChainPost:
+ * @self: the tracer instance
+ * @ts: the current timestamp
+ * @pad: the pad
+ * @res: the result of gst_pad_chain()
+ *
+ * Post-hook for gst_pad_chain() named "pad-chain-post".
+ *
+ * Since: 1.22
+ */
+typedef void (*GstTracerHookPadChainPost) (GObject * self, GstClockTime ts,
+    GstPad *pad, GstFlowReturn res);
+
+/**
+ * GST_TRACER_PAD_CHAIN_POST:
+ * @pad: a %GstPad
+ * @res: a %GstFlowReturn
+ *
+ * Dispatches the "pad-chain-post" hook.
+ *
+ * Since: 1.22
+ */
+#define GST_TRACER_PAD_CHAIN_POST(pad, res) G_STMT_START{ \
+  GST_TRACER_DISPATCH(GST_TRACER_QUARK(HOOK_PAD_CHAIN_POST), \
+    GstTracerHookPadChainPost, (GST_TRACER_ARGS, pad, res)); \
+}G_STMT_END
+
+/**
+ * GstTracerHookPadChainListPre:
+ * @self: the tracer instance
+ * @ts: the current timestamp
+ * @pad: the pad
+ * @list: the buffer-list
+ *
+ * Pre-hook for gst_pad_chain_list() named "pad-chain-list-pre".
+ *
+ * Since: 1.22
+ */
+typedef void (*GstTracerHookPadChainListPre) (GObject *self, GstClockTime ts,
+    GstPad *pad, GstBufferList *list);
+
+/**
+ * GST_TRACER_PAD_CHAIN_LIST_PRE:
+ * @pad: a %GstPad
+ * @list: a %GstBufferList
+ *
+ * Dispatches the "pad-chain-list-pre" hook.
+ *
+ * Since: 1.22
+ */
+#define GST_TRACER_PAD_CHAIN_LIST_PRE(pad, list) G_STMT_START{ \
+  GST_TRACER_DISPATCH(GST_TRACER_QUARK(HOOK_PAD_CHAIN_LIST_PRE), \
+    GstTracerHookPadChainListPre, (GST_TRACER_ARGS, pad, list)); \
+}G_STMT_END
+
+/**
+ * GstTracerHookPadChainListPost:
+ * @self: the tracer instance
+ * @ts: the current timestamp
+ * @pad: the pad
+ * @res: the result of gst_pad_chain_list()
+ *
+ * Post-hook for gst_pad_chain_list() named "pad-chain-list-post".
+ *
+ * Since: 1.22
+ */
+typedef void (*GstTracerHookPadChainListPost) (GObject *self, GstClockTime ts,
+    GstPad *pad,
+    GstFlowReturn res);
+
+/**
+ * GST_TRACER_PAD_CHAIN_LIST_POST:
+ * @pad: a %GstPad
+ * @res: a %GstFlowReturn
+ *
+ * Dispatches the "pad-chain-list-post" hook.
+ *
+ * Since: 1.22
+ */
+#define GST_TRACER_PAD_CHAIN_LIST_POST(pad, res) G_STMT_START{ \
+  GST_TRACER_DISPATCH(GST_TRACER_QUARK(HOOK_PAD_CHAIN_LIST_POST), \
+    GstTracerHookPadChainListPost, (GST_TRACER_ARGS, pad, res)); \
+}G_STMT_END
 
 #else /* !GST_DISABLE_GST_TRACER_HOOKS */
 
@@ -772,6 +888,10 @@ _priv_gst_tracing_deinit (void)
 #define GST_TRACER_OBJECT_REFFED(object, new_refcount)
 #define GST_TRACER_OBJECT_UNREFFED(object, new_refcount)
 #define GST_TRACER_PLUGIN_FEATURE_LOADED(feature)
+#define GST_TRACER_PAD_CHAIN_PRE(pad, buffer)
+#define GST_TRACER_PAD_CHAIN_POST(pad, res)
+#define GST_TRACER_PAD_CHAIN_LIST_PRE(pad, list)
+#define GST_TRACER_PAD_CHAIN_LIST_POST(pad, res)
 
 #endif /* GST_DISABLE_GST_TRACER_HOOKS */