Merge pull request #205 from edave64/shorter_sleep

Use a condition_variable to abort waiting in the server scan thread

src/multiplayer_server_scanner.cpp

@@ -1,5 +1,6 @@
 #include "multiplayer_server_scanner.h"
 #include "io/http/request.h"
+using namespace std::chrono_literals;
 
 ServerScanner::ServerScanner(int version_number, int server_port)
 : server_port(server_port), version_number(version_number)
@@ -15,6 +16,7 @@ ServerScanner::~ServerScanner()
 
 void ServerScanner::scanMasterServer(string url)
 {
+    abort_wait.notify_all();
     if (master_server_scan_thread.joinable())
         return;
     LOG(INFO) << "Switching to master server scanning";
@@ -45,6 +47,7 @@ void ServerScanner::scanLocalNetwork()
 
     LOG(INFO) << "Switching to local server scanning";
     master_server_url = "";
+    abort_wait.notify_all();
     if (master_server_scan_thread.joinable())
     {
         master_server_scan_thread.join();
@@ -209,8 +212,16 @@ void ServerScanner::masterServerScanThread()
                 }
             }
         }
-
-        for(int n=0;n<10 && !isDestroyed() && master_server_url != ""; n++)
-            std::this_thread::sleep_for(std::chrono::duration<float>(1.f));
+
+        if (!isDestroyed() && master_server_url != "") {
+            std::mutex wait_mutex;
+            std::unique_lock<std::mutex> lk(wait_mutex);
+            abort_wait.wait_for(lk, 10s);
+        }
     }
 }
+
+void ServerScanner::destroy() {
+    PObject::destroy();
+    abort_wait.notify_all();
+}

src/multiplayer_server_scanner.h

@@ -5,6 +5,7 @@
 #include "multiplayer_server.h"
 #include <thread>
 #include <mutex>
+#include <condition_variable>
 
 
 //Class to find all servers that have the correct version number. Creates a big nice list.
@@ -32,6 +33,7 @@ class ServerScanner : public Updatable
     string master_server_url;
     std::mutex server_list_mutex;
     std::thread master_server_scan_thread;
+    std::condition_variable abort_wait;
 
     std::function<void(sp::io::network::Address, string)> newServerCallback;
     std::function<void(sp::io::network::Address)> removedServerCallback;
@@ -40,6 +42,8 @@ class ServerScanner : public Updatable
     ServerScanner(int version_number, int server_port = defaultServerPort);
     virtual ~ServerScanner();
 
+    virtual void destroy() override;
+
     virtual void update(float delta) override;
     void addCallbacks(std::function<void(sp::io::network::Address, string)> newServerCallback, std::function<void(sp::io::network::Address)> removedServerCallback);