From d61a6cf4dc1d13fdfaea1f7b998c02f632d6e955 Mon Sep 17 00:00:00 2001
From: Aaro Altonen <aaro.altonen@tuni.fi>
Date: Wed, 18 Nov 2020 08:39:53 +0200
Subject: [PATCH] Protect access to create_stream() with a mutex

Multiple threads may access create_stream() for the same session
simultaneously which can cause problems if the access is not protected.
---
 include/session.hh | 3 +++
 src/session.cc     | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/include/session.hh b/include/session.hh
index b5cfec6..e72ca32 100644
--- a/include/session.hh
+++ b/include/session.hh
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mutex>
 #include <string>
 #include <vector>
 
@@ -47,5 +48,7 @@ namespace uvg_rtp {
 
             /* All media streams of this session */
             std::unordered_map<uint32_t, uvg_rtp::media_stream *> streams_;
+
+            std::mutex session_mtx_;
     };
 };
diff --git a/src/session.cc b/src/session.cc
index 1859883..c4c6399 100644
--- a/src/session.cc
+++ b/src/session.cc
@@ -30,6 +30,8 @@ uvg_rtp::session::~session()
 
 uvg_rtp::media_stream *uvg_rtp::session::create_stream(int r_port, int s_port, rtp_format_t fmt, int flags)
 {
+    std::lock_guard<std::mutex> m(session_mtx_);
+
     uvg_rtp::media_stream *stream = nullptr;
 
     if (flags & RCE_SYSTEM_CALL_DISPATCHER) {