Input: Improve Controller Interface devices threading

This specific issue was already addressed by https://github.com/dolphin-emu/dolphin/pull/11635
though I felt like there was something more we could do, and wasn't too happy with the
likelihood of devices update calls being skipped (due to `m_devices_population_mutex` being locked).

1 files changed, 9 insertions, 2 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/CoreDevice.h b/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
index a2176637ab..1667b42a00 100644
--- a/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
+++ b/Source/Core/InputCommon/ControllerInterface/CoreDevice.h
@@ -36,6 +36,12 @@ constexpr ControlState BATTERY_INPUT_MAX_VALUE = 100.0;
 
 namespace Core
 {
+enum class DeviceRemoval
+{
+  Remove,
+  Keep,
+};
+
 class Device
 {
 public:
@@ -118,7 +124,7 @@ public:
   virtual std::string GetName() const = 0;
   virtual std::string GetSource() const = 0;
   std::string GetQualifiedName() const;
-  virtual void UpdateInput() {}
+  virtual DeviceRemoval UpdateInput() { return DeviceRemoval::Keep; }
 
   // May be overridden to implement hotplug removal.
   // Currently handled on a per-backend basis but this could change.
@@ -242,7 +248,8 @@ public:
   std::recursive_mutex& GetDevicesMutex() const { return m_devices_mutex; }
 
 protected:
-  // Exclusively needed when reading/writing "m_devices"
+  // Exclusively needed when reading/writing the "m_devices" array.
+  // Not needed when individually readring/writing a single device ptr.
   mutable std::recursive_mutex m_devices_mutex;
   std::vector<std::shared_ptr<Device>> m_devices;
 };