Remove almost all instances of "volatile" keyword.

As Tiffany pointed out in Bugzilla, volatile is not useful for thread safety:

https://software.intel.com/en-us/blogs/2007/11/30/volatile-almost-useless-for-multi-threaded-programming/

Some of these volatiles didn't need to be, some were otherwise protected by
spinlocks or mutexes, and some got moved over to SDL_atomic_t data, etc.

Fixes Bugzilla #3220.

3 files changed, 5 insertions, 5 deletions

diff --git a/src/haptic/windows/SDL_windowshaptic.c b/src/haptic/windows/SDL_windowshaptic.c
index 0c038fb1b9..c6bcba1f31 100644
--- a/src/haptic/windows/SDL_windowshaptic.c
+++ b/src/haptic/windows/SDL_windowshaptic.c
@@ -255,7 +255,7 @@ SDL_SYS_HapticQuit(void)
     for (hapticitem = SDL_haptics; hapticitem; hapticitem = hapticitem->next) {
         if ((hapticitem->hwdata->bXInputHaptic) && (hapticitem->hwdata->thread)) {
             /* we _have_ to stop the thread before we free the XInput DLL! */
-            hapticitem->hwdata->stopThread = 1;
+            SDL_AtomicSet(&hapticitem->hwdata->stopThread, 1);
             SDL_WaitThread(hapticitem->hwdata->thread, NULL);
             hapticitem->hwdata->thread = NULL;
         }
diff --git a/src/haptic/windows/SDL_windowshaptic_c.h b/src/haptic/windows/SDL_windowshaptic_c.h
index 89fdd2cb9c..f344264420 100644
--- a/src/haptic/windows/SDL_windowshaptic_c.h
+++ b/src/haptic/windows/SDL_windowshaptic_c.h
@@ -42,8 +42,8 @@ struct haptic_hwdata
     Uint8 userid; /* XInput userid index for this joystick */
     SDL_Thread *thread;
     SDL_mutex *mutex;
-    volatile Uint32 stopTicks;
-    volatile int stopThread;
+    Uint32 stopTicks;
+    SDL_atomic_t stopThread;
 };
 
 
diff --git a/src/haptic/windows/SDL_xinputhaptic.c b/src/haptic/windows/SDL_xinputhaptic.c
index a46ae5f97d..aefbabbdaa 100644
--- a/src/haptic/windows/SDL_xinputhaptic.c
+++ b/src/haptic/windows/SDL_xinputhaptic.c
@@ -146,7 +146,7 @@ SDL_RunXInputHaptic(void *arg)
 {
     struct haptic_hwdata *hwdata = (struct haptic_hwdata *) arg;
 
-    while (!hwdata->stopThread) {
+    while (!SDL_AtomicGet(&hwdata->stopThread)) {
         SDL_Delay(50);
         SDL_LockMutex(hwdata->mutex);
         /* If we're currently running and need to stop... */
@@ -261,7 +261,7 @@ SDL_XINPUT_HapticOpenFromJoystick(SDL_Haptic * haptic, SDL_Joystick * joystick)
 void
 SDL_XINPUT_HapticClose(SDL_Haptic * haptic)
 {
-    haptic->hwdata->stopThread = 1;
+    SDL_AtomicSet(&haptic->hwdata->stopThread, 1);
     SDL_WaitThread(haptic->hwdata->thread, NULL);
     SDL_DestroyMutex(haptic->hwdata->mutex);
 }