pupnp: don't block on futures on connectivity change

Change-Id: I4e05d780481c340e288fcbb56898f30fb40bf90c

src/upnp/protocol/pupnp/pupnp.cpp

@@ -171,8 +171,8 @@ PUPnP::PUPnP()
                     }
                     lk.lock();
 
-                    // Move back failed items to end of list
-                    dwnldlXmlList_.splice(dwnldlXmlList_.end(), xmlList);
+                    // Move back timed-out items to list
+                    dwnldlXmlList_.splice(dwnldlXmlList_.begin(), xmlList);
                     // Handle successful downloads
                     for (auto& item : finished) {
                         auto result = item.get();
@@ -181,6 +181,13 @@ PUPnP::PUPnP()
                         }
                     }
                 }
+                for (auto it = cancelXmlList_.begin(); it != cancelXmlList_.end();) {
+                    if (it->wait_for(std::chrono::seconds(0)) == std::future_status::ready) {
+                        it = cancelXmlList_.erase(it);
+                    } else {
+                        ++it;
+                    }
+                }
             }
         }
 
@@ -201,6 +208,7 @@ PUPnP::~PUPnP()
         validIgdList_.clear();
         cpDeviceList_.clear();
         dwnldlXmlList_.clear();
+        cancelXmlList_.clear();
     }
 
     // Notify thread to terminate. UpnpFinish function will get called.
@@ -217,7 +225,7 @@ PUPnP::clearIgds()
     std::lock_guard<std::mutex> lk(validIgdMutex_);
 
     // Clear all internal lists.
-    dwnldlXmlList_.clear();
+    cancelXmlList_.splice(cancelXmlList_.end(), dwnldlXmlList_);
     validIgdList_.clear();
     cpDeviceList_.clear();
 }

src/upnp/protocol/pupnp/pupnp.h

@@ -147,7 +147,8 @@ private:
 
     std::map<std::string, std::shared_ptr<IGD>> validIgdList_;  // Map of valid IGDs with their UDN (universal Id).
     std::set<std::string> cpDeviceList_;                        // Control point device list containing the device ID and device subscription event url.
-    std::list<std::future<pIGDInfo>> dwnldlXmlList_;      // List of shared_futures for blocking xml download function calls.
+    std::list<std::future<pIGDInfo>> dwnldlXmlList_;            // List of futures for blocking xml download function calls.
+    std::list<std::future<pIGDInfo>> cancelXmlList_;  // List of abandoned documents
 
     std::mutex ctrlptMutex_;                                    // Mutex for client handle protection.
     UpnpClient_Handle ctrlptHandle_ {-1};                       // Control point handle.