Commit e86f494317e81820ea6d72caecf1134a9c3c2061

Sam Lantinga 2023-02-16T09:50:04

Hold the joystick lock while opening the HID device on non-Android platforms On Windows the main thread can be enumerating DirectInput devices while the Windows.Gaming.Input thread is calling back with a new controller available, and in this case HIDAPI_IsDevicePresent() returned false since the controller initialization hadn't completed yet, creating a duplicate controller. Fixes https://github.com/libsdl-org/SDL/issues/7304 (cherry picked from commit ece8a7bb8e2dae9cb53115980cea9ef1213a0160)

diff --git a/src/joystick/hidapi/SDL_hidapijoystick.c b/src/joystick/hidapi/SDL_hidapijoystick.c
index 47300bc..e7d2b91 100644
--- a/src/joystick/hidapi/SDL_hidapijoystick.c
+++ b/src/joystick/hidapi/SDL_hidapijoystick.c
@@ -380,44 +380,65 @@ static void HIDAPI_SetupDeviceDriver(SDL_HIDAPI_Device *device, SDL_bool *remove
     if (HIDAPI_GetDeviceDriver(device)) {
         /* We might have a device driver for this device, try opening it and see */
         if (device->num_children == 0) {
+            SDL_hid_device *dev;
+
+            /* Wait a little bit for the device to initialize */
+            SDL_Delay(10);
+
+#ifdef __ANDROID__
             /* On Android we need to leave joysticks unlocked because it calls
              * out to the main thread for permissions and the main thread can
              * be in the process of handling controller input.
              *
              * See https://github.com/libsdl-org/SDL/issues/6347 for details
              */
-            int lock_count = 0;
-            SDL_HIDAPI_Device *curr;
-            SDL_hid_device *dev;
-            char *path = SDL_strdup(device->path);
+            {
+                SDL_HIDAPI_Device *curr;
+                int lock_count = 0;
+                char *path = SDL_strdup(device->path);
 
-            /* Wait a little bit for the device to initialize */
-            SDL_Delay(10);
+                /* Wait a little bit for the device to initialize */
+                SDL_Delay(10);
 
-            SDL_AssertJoysticksLocked();
-            while (SDL_JoysticksLocked()) {
-                ++lock_count;
-                SDL_UnlockJoysticks();
-            }
+                SDL_AssertJoysticksLocked();
+                while (SDL_JoysticksLocked()) {
+                    ++lock_count;
+                    SDL_UnlockJoysticks();
+                }
 
-            dev = SDL_hid_open_path(path, 0);
+                dev = SDL_hid_open_path(path, 0);
 
-            while (lock_count > 0) {
-                --lock_count;
-                SDL_LockJoysticks();
-            }
-            SDL_free(path);
+                while (lock_count > 0) {
+                    --lock_count;
+                    SDL_LockJoysticks();
+                }
+                SDL_free(path);
 
-            /* Make sure the device didn't get removed while opening the HID path */
-            for (curr = SDL_HIDAPI_devices; curr && curr != device; curr = curr->next) {
-            }
-            if (curr == NULL) {
-                *removed = SDL_TRUE;
-                if (dev) {
-                    SDL_hid_close(dev);
+                /* Make sure the device didn't get removed while opening the HID path */
+                for (curr = SDL_HIDAPI_devices; curr && curr != device; curr = curr->next) {
+                    continue;
+                }
+                if (curr == NULL) {
+                    *removed = SDL_TRUE;
+                    if (dev) {
+                        SDL_hid_close(dev);
+                    }
+                    return;
                 }
-                return;
             }
+#else
+            /* On other platforms we want to keep the lock so other threads wait for
+             * us to finish opening the controller before checking to see whether the
+             * HIDAPI driver is handling the device.
+             *
+             * On Windows, for example, the main thread can be enumerating DirectInput
+             * devices while the Windows.Gaming.Input thread is calling back with a new
+             * controller available.
+             *
+             * See https://github.com/libsdl-org/SDL/issues/7304 for details.
+             */
+            dev = SDL_hid_open_path(device->path, 0);
+#endif
 
             if (dev == NULL) {
                 SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,