Commit 92d3fc4883b8ea814fa14450157f6b75e01e40b8
2022-08-30T12:58:38
Fixed deadlock when shutting down the Windows joystick system
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diff --git a/src/joystick/SDL_joystick.c b/src/joystick/SDL_joystick.c
index cd41ca5..f9c09cf 100644
--- a/src/joystick/SDL_joystick.c
+++ b/src/joystick/SDL_joystick.c
@@ -130,6 +130,12 @@ SDL_JoysticksInitialized(void)
return SDL_joysticks_initialized;
}
+SDL_bool
+SDL_JoysticksQuitting(void)
+{
+ return SDL_joysticks_quitting;
+}
+
void
SDL_LockJoysticks(void)
{
@@ -159,18 +165,12 @@ SDL_UnlockJoysticks(void)
}
}
-static void
+void
SDL_AssertJoysticksLocked(void)
{
SDL_assert(SDL_joysticks_locked > 0);
}
-SDL_bool
-SDL_JoysticksQuitting(void)
-{
- return SDL_joysticks_quitting;
-}
-
/*
* Get the driver and device index for an API device index
* This should be called while the joystick lock is held, to prevent another thread from updating the list
diff --git a/src/joystick/SDL_joystick_c.h b/src/joystick/SDL_joystick_c.h
index 51112a6..82311a0 100644
--- a/src/joystick/SDL_joystick_c.h
+++ b/src/joystick/SDL_joystick_c.h
@@ -45,6 +45,9 @@ extern SDL_bool SDL_JoysticksInitialized(void);
/* Return whether the joystick system is shutting down */
extern SDL_bool SDL_JoysticksQuitting(void);
+/* Make sure we currently have the joysticks locked */
+extern void SDL_AssertJoysticksLocked(void);
+
/* Function to get the next available joystick instance ID */
extern SDL_JoystickID SDL_GetNextJoystickInstanceID(void);
diff --git a/src/joystick/windows/SDL_windowsjoystick.c b/src/joystick/windows/SDL_windowsjoystick.c
index 0b42ed6..a79e340 100644
--- a/src/joystick/windows/SDL_windowsjoystick.c
+++ b/src/joystick/windows/SDL_windowsjoystick.c
@@ -429,7 +429,12 @@ SDL_StopJoystickThread(void)
SDL_CondBroadcast(s_condJoystickThread); /* signal the joystick thread to quit */
SDL_UnlockMutex(s_mutexJoyStickEnum);
PostThreadMessage(SDL_GetThreadID(s_joystickThread), WM_QUIT, 0, 0);
+
+ /* Unlock joysticks while the joystick thread finishes processing messages */
+ SDL_AssertJoysticksLocked();
+ SDL_UnlockJoysticks();
SDL_WaitThread(s_joystickThread, NULL); /* wait for it to bugger off */
+ SDL_LockJoysticks();
SDL_DestroyCond(s_condJoystickThread);
s_condJoystickThread = NULL;