From 25fec76ea9b154c9e7269531641c32ec611f497a Mon Sep 17 00:00:00 2001
From: winlin <winlin@vip.126.com>
Date: Tue, 17 Mar 2020 12:33:08 +0800
Subject: [PATCH] For #1638, #307, switch to RTC session context cid for
 reusing UDP ports

---
 trunk/src/app/srs_app_rtc_conn.cpp | 24 ++++++++++++++++++++++--
 trunk/src/app/srs_app_rtc_conn.hpp |  7 ++++++-
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/trunk/src/app/srs_app_rtc_conn.cpp b/trunk/src/app/srs_app_rtc_conn.cpp
index 2361b721b..c3629db20 100644
--- a/trunk/src/app/srs_app_rtc_conn.cpp
+++ b/trunk/src/app/srs_app_rtc_conn.cpp
@@ -716,7 +716,7 @@ void SrsRtcSenderThread::send_and_free_messages(SrsSharedPtrMessage** msgs, int
     }
 }
 
-SrsRtcSession::SrsRtcSession(SrsServer* svr, SrsRtcServer* rtc_svr, const SrsRequest& req, const std::string& un)
+SrsRtcSession::SrsRtcSession(SrsServer* svr, SrsRtcServer* rtc_svr, const SrsRequest& req, const std::string& un, int context_id)
 {
     server = svr;
     rtc_server = rtc_svr;
@@ -730,6 +730,8 @@ SrsRtcSession::SrsRtcSession(SrsServer* svr, SrsRtcServer* rtc_svr, const SrsReq
 
     request = req;
     source = NULL;
+
+    cid = context_id;
 }
 
 SrsRtcSession::~SrsRtcSession()
@@ -742,6 +744,11 @@ SrsRtcSession::~SrsRtcSession()
     srs_freep(strd);
 }
 
+void SrsRtcSession::switch_to_context()
+{
+    _srs_context->set_id(cid);
+}
+
 srs_error_t SrsRtcSession::on_stun(SrsUdpMuxSocket* udp_mux_skt, SrsStunPacket* stun_req)
 {
     srs_error_t err = srs_success;
@@ -1215,7 +1222,8 @@ SrsRtcSession* SrsRtcServer::create_rtc_session(const SrsRequest& req, const Srs
             break;
     }
 
-    SrsRtcSession* session = new SrsRtcSession(server, this, req, username);
+    int cid = _srs_context->get_id();
+    SrsRtcSession* session = new SrsRtcSession(server, this, req, username, cid);
     map_username_session.insert(make_pair(username, session));
 
     local_sdp.set_ice_ufrag(local_ufrag);
@@ -1256,6 +1264,10 @@ srs_error_t SrsRtcServer::on_stun(SrsUdpMuxSocket* udp_mux_skt)
         return srs_error_new(ERROR_RTC_STUN, "can not find rtc_session, stun username=%s", username.c_str());
     }
 
+    // Now, we got the RTC session to handle the packet, switch to its context
+    // to make all logs write to the "correct" pid+cid.
+    rtc_session->switch_to_context();
+
     return rtc_session->on_stun(udp_mux_skt, &stun_req);
 }
 
@@ -1267,6 +1279,10 @@ srs_error_t SrsRtcServer::on_dtls(SrsUdpMuxSocket* udp_mux_skt)
         return srs_error_new(ERROR_RTC_DTLS, "can not find rtc session by peer_id=%s", udp_mux_skt->get_peer_id().c_str());
     }
 
+    // Now, we got the RTC session to handle the packet, switch to its context
+    // to make all logs write to the "correct" pid+cid.
+    rtc_session->switch_to_context();
+
     return rtc_session->on_dtls(udp_mux_skt);
 }
 
@@ -1280,6 +1296,10 @@ srs_error_t SrsRtcServer::on_rtp_or_rtcp(SrsUdpMuxSocket* udp_mux_skt)
         return srs_error_new(ERROR_RTC_RTP, "can not find rtc session by peer_id=%s", udp_mux_skt->get_peer_id().c_str());
     }
 
+    // Now, we got the RTC session to handle the packet, switch to its context
+    // to make all logs write to the "correct" pid+cid.
+    rtc_session->switch_to_context();
+
     if (is_rtcp(reinterpret_cast<const uint8_t*>(udp_mux_skt->data()), udp_mux_skt->size())) {
         err = rtc_session->on_rtcp(udp_mux_skt);
     } else {
diff --git a/trunk/src/app/srs_app_rtc_conn.hpp b/trunk/src/app/srs_app_rtc_conn.hpp
index 422e6ca9d..57914dd7d 100644
--- a/trunk/src/app/srs_app_rtc_conn.hpp
+++ b/trunk/src/app/srs_app_rtc_conn.hpp
@@ -194,11 +194,14 @@ private:
     std::string username;
     std::string peer_id;
     srs_utime_t last_stun_time;
+private:
+    // For each RTC session, we use a specified cid for debugging logs.
+    int cid;
 public:
     SrsRequest request;
     SrsSource* source;
 public:
-    SrsRtcSession(SrsServer* svr, SrsRtcServer* rtc_svr, const SrsRequest& req, const std::string& un);
+    SrsRtcSession(SrsServer* svr, SrsRtcServer* rtc_svr, const SrsRequest& req, const std::string& un, int context_id);
     virtual ~SrsRtcSession();
 public:
     SrsSdp* get_local_sdp() { return &local_sdp; }
@@ -214,6 +217,8 @@ public:
 
     std::string get_peer_id() const { return peer_id; }
     void set_peer_id(const std::string& id) { peer_id = id; }
+
+    void switch_to_context();
 public:
     srs_error_t on_stun(SrsUdpMuxSocket* udp_mux_skt, SrsStunPacket* stun_req);
     srs_error_t on_dtls(SrsUdpMuxSocket* udp_mux_skt);