rtprecv: ensure that stopping the rtp src task does not critical

When pad a released, then we were removing the pad from an internal
list. If the pad was not already deactivated, the deactiviation would
attempt to look for the pad in that list and panic if it was not there.

Fix by delaying removal of the pad from the list until after pad
deactivation occurs.

Also includes test.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1618>

net/rtp/src/rtpbin2/rtprecv.rs

@@ -119,12 +119,14 @@ impl futures::stream::Stream for JitterBufferStream {
                             if pending_item.is_some() {
                                 // but only after sending the previous pending item
                                 next_pending_item = Some(item);
-                                break
+                                break;
                             }
                         }
                         JitterBufferItem::Packet(ref packet) => {
                             match pending_item {
-                                Some(JitterBufferItem::Event(_) | JitterBufferItem::Query(_, _)) => unreachable!(),
+                                Some(
+                                    JitterBufferItem::Event(_) | JitterBufferItem::Query(_, _),
+                                ) => unreachable!(),
                                 Some(JitterBufferItem::Packet(pending_buffer)) => {
                                     let mut list = gst::BufferList::new();
                                     let list_mut = list.make_mut();
@@ -1862,6 +1864,7 @@ impl ElementImpl for RtpRecv {
         let mut state = self.state.lock().unwrap();
         let mut removed_pads = vec![];
         let mut removed_session_ids = vec![];
+        let mut removed_srcpads_session_ids = vec![];
         if let Some(&id) = state.pads_session_id_map.get(pad) {
             removed_pads.push(pad.clone());
             if let Some(session) = state.mut_session_by_id(id) {
@@ -1869,7 +1872,7 @@ impl ElementImpl for RtpRecv {
                     session.rtp_recv_sinkpad = None;
                     removed_pads.extend(session.rtp_recv_srcpads.iter().map(|r| r.pad.clone()));
                     session.recv_flow_combiner.lock().unwrap().clear();
-                    session.rtp_recv_srcpads.clear();
+                    removed_srcpads_session_ids.push(id);
                     session.recv_store.clear();
                 }
 
@@ -1882,6 +1885,10 @@ impl ElementImpl for RtpRecv {
                 }
             }
         }
+
+        for pad in removed_pads.iter() {
+            state.pads_session_id_map.remove(pad);
+        }
         drop(state);
 
         for pad in removed_pads.iter() {
@@ -1894,9 +1901,10 @@ impl ElementImpl for RtpRecv {
 
         {
             let mut state = self.state.lock().unwrap();
-
-            for pad in removed_pads.iter() {
-                state.pads_session_id_map.remove(pad);
+            for id in removed_srcpads_session_ids {
+                if let Some(session) = state.mut_session_by_id(id) {
+                    session.rtp_recv_srcpads.clear();
+                }
             }
             for id in removed_session_ids {
                 if let Some(session) = state.mut_session_by_id(id) {

net/rtp/tests/rtpbin2.rs

@@ -55,8 +55,11 @@ struct PacketInfo {
 }
 
 impl PacketInfo {
-    fn generate_buffer(&self) -> gst::Buffer {
-        generate_rtp_buffer(self.seq_no, self.rtp_ts, self.payload_len)
+    fn generate_buffer(&self, dts: Option<gst::ClockTime>) -> gst::Buffer {
+        let mut buf = generate_rtp_buffer(self.seq_no, self.rtp_ts, self.payload_len);
+        let buf_mut = buf.make_mut();
+        buf_mut.set_dts(dts);
+        buf
     }
 }
 
@@ -91,7 +94,7 @@ where
         let mut list = gst::BufferList::new();
         let list_mut = list.make_mut();
         for packet in packets {
-            list_mut.add(packet.generate_buffer());
+            list_mut.add(packet.generate_buffer(None));
         }
         let push_pad = h
             .element()
@@ -103,7 +106,7 @@ where
         push_pad.push_list(list).unwrap();
     } else {
         for packet in packets {
-            h.push(packet.generate_buffer()).unwrap();
+            h.push(packet.generate_buffer(None)).unwrap();
         }
     }
 }
@@ -183,7 +186,7 @@ fn test_send_benchmark() {
                 rtp_ts: i as u32,
                 payload_len: 8,
             }
-            .generate_buffer(),
+            .generate_buffer(None),
         )
     }
 
@@ -231,7 +234,7 @@ fn test_send_list_benchmark() {
                 rtp_ts: i as u32,
                 payload_len: 8,
             }
-            .generate_buffer(),
+            .generate_buffer(None),
         );
     }
     let mut h = send_init();
@@ -330,12 +333,12 @@ where
         let mut list = gst::BufferList::new();
         let list_mut = list.make_mut();
         for packet in packets {
-            list_mut.add(packet.generate_buffer());
+            list_mut.add(packet.generate_buffer(None));
         }
         push_pad.push_list(list).unwrap();
     } else {
         for packet in packets {
-            push_pad.push(packet.generate_buffer()).unwrap();
+            push_pad.push(packet.generate_buffer(None)).unwrap();
         }
     }
 }
@@ -471,7 +474,8 @@ fn test_receive_flush() {
 fn test_receive_benchmark() {
     init();
     let clock = gst::SystemClock::obtain();
-    const N_PACKETS: usize = 1024 * 1024;
+    //const N_PACKETS: usize = 1024 * 1024;
+    const N_PACKETS: usize = 1024;
     let mut packets = Vec::with_capacity(N_PACKETS);
     for i in 0..N_PACKETS {
         packets.push(
@@ -480,7 +484,7 @@ fn test_receive_benchmark() {
                 rtp_ts: i as u32,
                 payload_len: 8,
             }
-            .generate_buffer(),
+            .generate_buffer(None),
         )
     }
 
@@ -554,7 +558,7 @@ fn test_receive_list_benchmark() {
                     rtp_ts: (p * N_PACKETS + i) as u32,
                     payload_len: 8,
                 }
-                .generate_buffer(),
+                .generate_buffer(None),
             );
         }
         lists.push(list);
@@ -574,7 +578,10 @@ fn test_receive_list_benchmark() {
             let buffer = inner.pull().unwrap();
             let mapped = buffer.map_readable().unwrap();
             let rtp = rtp_types::RtpPacket::parse(&mapped).unwrap();
-            assert_eq!(rtp.sequence_number(), ((p * N_PACKETS + i) % u16::MAX as usize) as u16);
+            assert_eq!(
+                rtp.sequence_number(),
+                ((p * N_PACKETS + i) % u16::MAX as usize) as u16
+            );
         }
     }
 
@@ -591,3 +598,66 @@ fn test_receive_list_benchmark() {
         pull_time.display()
     );
 }
+
+#[test]
+fn recv_release_sink_pad() {
+    init();
+
+    let id = next_element_counter();
+
+    let elem = gst::ElementFactory::make("rtprecv")
+        .property("rtp-id", id.to_string())
+        .build()
+        .unwrap();
+    elem.set_state(gst::State::Playing).unwrap();
+    let sinkpad = elem.request_pad_simple("rtp_sink_0").unwrap();
+    let stream_start = gst::event::StreamStart::new("random");
+    sinkpad.send_event(stream_start);
+    let caps = Caps::builder("application/x-rtp")
+        .field("media", "audio")
+        .field("payload", TEST_PT as i32)
+        .field("clock-rate", TEST_CLOCK_RATE as i32)
+        .field("encoding-name", "custom-test")
+        .build();
+    sinkpad.send_event(gst::event::Caps::new(&caps));
+    let segment = gst::FormattedSegment::<gst::ClockTime>::new();
+    sinkpad.send_event(gst::event::Segment::new(&segment));
+
+    let (sender, recv) = std::sync::mpsc::sync_channel(1);
+    elem.connect_pad_added({
+        let sender = sender.clone();
+        move |_elem, pad| {
+            let other_pad = gst::Pad::builder(gst::PadDirection::Sink)
+                .chain_function(|_pad, _parent, _buffer| Ok(gst::FlowSuccess::Ok))
+                .build();
+            other_pad.set_active(true).unwrap();
+            pad.link(&other_pad).unwrap();
+            sender.send(other_pad).unwrap();
+        }
+    });
+    // push two buffers to get past the rtpsource validation
+    sinkpad
+        .chain(
+            PacketInfo {
+                seq_no: 30,
+                rtp_ts: 10,
+                payload_len: 4,
+            }
+            .generate_buffer(Some(gst::ClockTime::from_mseconds(50))),
+        )
+        .unwrap();
+    sinkpad
+        .chain(
+            PacketInfo {
+                seq_no: 31,
+                rtp_ts: 10,
+                payload_len: 4,
+            }
+            .generate_buffer(Some(gst::ClockTime::from_mseconds(100))),
+        )
+        .unwrap();
+    let _other_pad = recv.recv().unwrap();
+
+    elem.release_request_pad(&sinkpad);
+    elem.set_state(gst::State::Null).unwrap();
+}