Centralize SDL input subsystem ownership for hotplug recovery

2026-02-12 07:57:41 -07:00 · 2026-02-12 07:57:41 -07:00 · d174341b6d
commit d174341b6d
parent e94f0c5990
7 changed files with 315 additions and 117 deletions
--- a/app/streaming/input/sdlinputsubsystems.cpp
+++ b/app/streaming/input/sdlinputsubsystems.cpp
@ -0,0 +1,191 @@
+#include "streaming/input/sdlinputsubsystems.h"
+
+#include "settings/mappingmanager.h"
+
+namespace {
+
+int s_JoystickRefs = 0;
+int s_GameControllerRefs = 0;
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+int s_HapticRefs = 0;
+#endif
+
+bool retainSubsystem(Uint32 subsystem, int& refs, const char* subsystemName, const char* ownerTag)
+{
+    if (refs == 0 && SDL_InitSubSystem(subsystem) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to initialize %s subsystem for %s: %s",
+                     subsystemName,
+                     ownerTag,
+                     SDL_GetError());
+        return false;
+    }
+
+    refs++;
+    return true;
+}
+
+void releaseSubsystem(Uint32 subsystem, int& refs, const char* subsystemName, const char* ownerTag)
+{
+    if (refs <= 0) {
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "Ignoring unbalanced release of %s subsystem for %s",
+                    subsystemName,
+                    ownerTag);
+        refs = 0;
+        return;
+    }
+
+    refs--;
+    if (refs == 0) {
+        SDL_QuitSubSystem(subsystem);
+    }
+}
+
+}
+
+namespace SdlInputSubsystems {
+
+bool acquire(const char* ownerTag, const LeaseOptions& options)
+{
+    bool acquiredJoystick = false;
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    bool acquiredGameController = false;
+    bool acquiredHaptic = false;
+#endif
+
+    if (options.joystick) {
+        if (!retainSubsystem(SDL_INIT_JOYSTICK, s_JoystickRefs, "joystick", ownerTag)) {
+            return false;
+        }
+        acquiredJoystick = true;
+    }
+
+    if (options.gameController) {
+        if (!retainSubsystem(SDL_INIT_GAMECONTROLLER, s_GameControllerRefs, "gamecontroller", ownerTag)) {
+            if (acquiredJoystick) {
+                releaseSubsystem(SDL_INIT_JOYSTICK, s_JoystickRefs, "joystick", ownerTag);
+            }
+            return false;
+        }
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+        acquiredGameController = true;
+#endif
+    }
+
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    if (options.haptic) {
+        if (!retainSubsystem(SDL_INIT_HAPTIC, s_HapticRefs, "haptic", ownerTag)) {
+            if (acquiredGameController) {
+                releaseSubsystem(SDL_INIT_GAMECONTROLLER, s_GameControllerRefs, "gamecontroller", ownerTag);
+            }
+            if (acquiredJoystick) {
+                releaseSubsystem(SDL_INIT_JOYSTICK, s_JoystickRefs, "joystick", ownerTag);
+            }
+            return false;
+        }
+        acquiredHaptic = true;
+    }
+#endif
+
+    if (options.applyMappings) {
+        MappingManager mappingManager;
+        mappingManager.applyMappings();
+    }
+
+    if (options.flushControllerDeviceEvents) {
+        SDL_FlushEvent(SDL_CONTROLLERDEVICEADDED);
+        SDL_FlushEvent(SDL_CONTROLLERDEVICEREMOVED);
+    }
+
+    return true;
+}
+
+void release(const char* ownerTag, const LeaseOptions& options)
+{
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    if (options.haptic) {
+        releaseSubsystem(SDL_INIT_HAPTIC, s_HapticRefs, "haptic", ownerTag);
+    }
+#endif
+
+    if (options.gameController) {
+        releaseSubsystem(SDL_INIT_GAMECONTROLLER, s_GameControllerRefs, "gamecontroller", ownerTag);
+    }
+
+    if (options.joystick) {
+        releaseSubsystem(SDL_INIT_JOYSTICK, s_JoystickRefs, "joystick", ownerTag);
+    }
+}
+
+bool hasExclusiveGamepadOwnership()
+{
+    if (s_JoystickRefs != 1 || s_GameControllerRefs != 1) {
+        return false;
+    }
+
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    if (s_HapticRefs != 1) {
+        return false;
+    }
+#endif
+
+    return true;
+}
+
+bool reenumerateGamepadSubsystems(const char* ownerTag)
+{
+    if (!hasExclusiveGamepadOwnership()) {
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "Skipping subsystem re-enumeration for %s due to shared ownership (joystick=%d gamecontroller=%d)",
+                    ownerTag,
+                    s_JoystickRefs,
+                    s_GameControllerRefs);
+        return false;
+    }
+
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    SDL_QuitSubSystem(SDL_INIT_HAPTIC);
+#endif
+    SDL_QuitSubSystem(SDL_INIT_GAMECONTROLLER);
+    SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
+
+    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to reinitialize joystick subsystem for %s: %s",
+                     ownerTag,
+                     SDL_GetError());
+        return false;
+    }
+
+    if (SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to reinitialize gamecontroller subsystem for %s: %s",
+                     ownerTag,
+                     SDL_GetError());
+        return false;
+    }
+
+#if !SDL_VERSION_ATLEAST(2, 0, 9)
+    if (SDL_InitSubSystem(SDL_INIT_HAPTIC) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to reinitialize haptic subsystem for %s: %s",
+                     ownerTag,
+                     SDL_GetError());
+        return false;
+    }
+#endif
+
+    MappingManager mappingManager;
+    mappingManager.applyMappings();
+
+    SDL_JoystickUpdate();
+    SDL_GameControllerUpdate();
+
+    SDL_FlushEvents(SDL_JOYDEVICEADDED, SDL_JOYDEVICEREMOVED);
+    SDL_FlushEvents(SDL_CONTROLLERDEVICEADDED, SDL_CONTROLLERDEVICEREMAPPED);
+
+    return true;
+}
+
+}