[QC-403] Protect pendingInfoRegions from concurrent access (#4371)

Author: knopers8

Framework/Core/include/Framework/DataProcessingDevice.h

@@ -28,6 +28,7 @@
 #include <fairmq/FairMQParts.h>
 
 #include <memory>
+#include <mutex>
 
 namespace o2::framework
 {
@@ -129,6 +130,7 @@ class DataProcessingDevice : public FairMQDevice
   uint64_t mBeginIterationTimestamp = 0;             /// The timestamp of when the current ConditionalRun was started
   DataProcessingStats mStats;                        /// Stats about the actual data processing.
   std::vector<FairMQRegionInfo> mPendingRegionInfos; /// A list of the region infos not yet notified.
+  std::mutex mRegionInfoMutex;
   enum TerminationPolicy mErrorPolicy = TerminationPolicy::WAIT; /// What to do when an error arises
   bool mWasActive = false;                                       /// Whether or not the device was active at last iteration.
 };

Framework/Core/src/DataProcessingDevice.cxx

@@ -274,7 +274,8 @@ void on_signal_callback(uv_signal_t* handle, int signum)
 void DataProcessingDevice::InitTask()
 {
   for (auto& channel : fChannels) {
-    channel.second.at(0).Transport()->SubscribeToRegionEvents([& pendingRegionInfos = mPendingRegionInfos](FairMQRegionInfo info) {
+    channel.second.at(0).Transport()->SubscribeToRegionEvents([& pendingRegionInfos = mPendingRegionInfos, &regionInfoMutex = mRegionInfoMutex](FairMQRegionInfo info) {
+      std::lock_guard<std::mutex> lock(regionInfoMutex);
       LOG(debug) << ">>> Region info event" << info.event;
       LOG(debug) << "id: " << info.id;
       LOG(debug) << "ptr: " << info.ptr;