WiimoteScannerBackend: Allow StopThreads to request that any Wiimote searching stops

Used by WiimoteScannerDarwin to know when to exit its runloop.

Source/Core/Core/HW/WiimoteReal/IOAndroid.h

@@ -48,6 +48,7 @@ public:
   bool IsReady() const override { return true; }
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override;
   void Update() override {}
+  void RequestStopSearching() override {}
 };
 }  // namespace WiimoteReal
 

Source/Core/Core/HW/WiimoteReal/IODummy.h

@@ -16,5 +16,6 @@ public:
   bool IsReady() const override { return false; }
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override {}
   void Update() override {}
+  void RequestStopSearching() override {}
 };
 }  // namespace WiimoteReal

Source/Core/Core/HW/WiimoteReal/IOLinux.h

@@ -47,6 +47,7 @@ public:
   bool IsReady() const override;
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override;
   void Update() override {}  // not needed on Linux
+  void RequestStopSearching() override {} // not needed on Linux
 private:
   int m_device_id;
   int m_device_sock;

Source/Core/Core/HW/WiimoteReal/IOWin.h

@@ -52,6 +52,7 @@ public:
   bool IsReady() const override;
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override;
   void Update() override;
+  void RequestStopSearching() override {}
 };
 }  // namespace WiimoteReal
 

Source/Core/Core/HW/WiimoteReal/IOdarwin.h

@@ -24,6 +24,7 @@ public:
   bool IsReady() const override;
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override;
   void Update() override {}  // not needed
+  void RequestStopSearching() override { m_stop_scanning = true; }
 private:
   IOBluetoothHostController* m_host_controller;
   bool m_stop_scanning = false;

Source/Core/Core/HW/WiimoteReal/IOhidapi.h

@@ -39,6 +39,7 @@ public:
   bool IsReady() const override;
   void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) override;
   void Update() override {}  // not needed for hidapi
+  void RequestStopSearching() override {} // not needed for hidapi
 };
 }  // namespace WiimoteReal
 

Source/Core/Core/HW/WiimoteReal/WiimoteReal.cpp

@@ -545,6 +545,12 @@ void WiimoteScanner::StopThread()
   if (m_scan_thread_running.TestAndClear())
   {
     SetScanMode(WiimoteScanMode::DO_NOT_SCAN);
+    
+    for (const auto& backend : m_backends)
+    {
+      backend->RequestStopSearching();
+    }
+    
     m_scan_thread.join();
   }
 }

Source/Core/Core/HW/WiimoteReal/WiimoteReal.h

@@ -1,4 +1,4 @@
-// Copyright 2008 Dolphin Emulator Project
+// Copyright 2008 Dolphin Emulator Project
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
@@ -155,6 +155,8 @@ public:
   virtual void FindWiimotes(std::vector<Wiimote*>&, Wiimote*&) = 0;
   // function called when not looking for more Wiimotes
   virtual void Update() = 0;
+  // requests the backend to stop scanning if FindWiimotes is blocking
+  virtual void RequestStopSearching() = 0;
 };
 
 enum class WiimoteScanMode