fix rtc over tcp crash when stop rtc publish.

@see https://github.com/ossrs/srs/issues/4220

trunk/src/app/srs_app_rtc_network.cpp

@@ -713,10 +713,12 @@ SrsRtcTcpConn::SrsRtcTcpConn(ISrsProtocolReadWriter* skt, std::string cip, int p
     delta_->set_io(skt_, skt_);
     session_ = NULL;
     pkt_ = new char[SRS_RTC_TCP_PACKET_MAX];
+    _srs_rtc_manager->subscribe(this);
 }
 
 SrsRtcTcpConn::~SrsRtcTcpConn()
 {
+    _srs_rtc_manager->unsubscribe(this);
     srs_freepa(pkt_);
     srs_freep(delta_);
     srs_freep(skt_);
@@ -808,6 +810,23 @@ srs_error_t SrsRtcTcpConn::cycle()
     return srs_success;
 }
 
+void SrsRtcTcpConn::on_before_dispose(ISrsResource* c)
+{
+    SrsRtcConnection* session = dynamic_cast<SrsRtcConnection*>(c);
+    if (session && session == session_) {
+        if (session_->tcp()->is_establelished()) {
+            session_->tcp()->set_state(SrsRtcNetworkStateClosed);
+            session_->expire();
+        }
+
+        session_ = NULL;
+    }
+}
+
+void SrsRtcTcpConn::on_disposing(ISrsResource* c)
+{
+}
+
 srs_error_t SrsRtcTcpConn::do_cycle()
 {
     srs_error_t err = srs_success;

trunk/src/app/srs_app_rtc_network.hpp

@@ -232,7 +232,7 @@ public:
 };
 
 // For WebRTC over TCP.
-class SrsRtcTcpConn : public ISrsConnection, public ISrsCoroutineHandler, public ISrsExecutorHandler
+class SrsRtcTcpConn : public ISrsConnection, public ISrsCoroutineHandler, public ISrsExecutorHandler, public ISrsDisposingHandler
 {
 private:
     // Because session references to this object, so we should directly use the session ptr.
@@ -277,6 +277,10 @@ public:
 // Interface ISrsCoroutineHandler
 public:
     virtual srs_error_t cycle();
+// Interface ISrsDisposingHandler
+public:
+    virtual void on_before_dispose(ISrsResource* c);
+    virtual void on_disposing(ISrsResource* c);
 private:
     virtual srs_error_t do_cycle();
     srs_error_t handshake();