dix: Rework Enter/Leave semaphore system.

Instead of a simple counter, use bits to keep track of which device is where
etc. When device enters a window (or sets focus), the bit matching the device
is set, when it leaves again, it is unset. If there are 0 bits set, then
Leave/Enter/Focus events may be sent to the client.

Same theory as before, but this should get around the insanity with
Grab/Ungrab special cases. Those cases are basically untested though.

dix/devices.c

@@ -224,8 +224,7 @@ EnableDevice(DeviceIntPtr dev)
             if (dev->spriteInfo->spriteOwner)
             {
                 InitializeSprite(dev, WindowTable[0]);
-                ((FocusSemaphoresPtr)dixLookupPrivate(&(WindowTable[0])->devPrivates,
+                ENTER_LEAVE_SEMAPHORE_SET(WindowTable[0], dev);
-                    FocusPrivatesKey))->enterleave++;
             }
             else if ((other = NextFreePointerDevice()) == NULL)
             {

dix/events.c

@@ -4393,7 +4393,7 @@ EnterLeaveEvent(
     GrabPtr	        grab = mouse->deviceGrab.grab;
     GrabPtr	        devgrab = mouse->deviceGrab.grab;
     Mask		mask;
-    int*                inWindow; /* no of sprites inside pWin */
+    int                 inWindow; /* zero if no sprites are in window */
     Bool                sendevent = FALSE;
 
     deviceEnterNotify   *devEnterLeave;
@@ -4446,7 +4446,6 @@ EnterLeaveEvent(
              IsParent(focus, pWin)))
         event.u.enterLeave.flags |= ELFlagFocus;
 
-    inWindow = &((FocusSemaphoresPtr)dixLookupPrivate(&pWin->devPrivates, FocusPrivatesKey))->enterleave;
 
     /*
      * Sending multiple core enter/leave events to the same window confuse the
@@ -4472,16 +4471,15 @@ EnterLeaveEvent(
      * NotifyNonlinearVirtual to C and nothing to B.
      */
 
-    if (event.u.u.detail != NotifyVirtual &&
+    /* Clear bit for device, but don't worry about SDs. */
-            event.u.u.detail != NotifyNonlinearVirtual)
+    if (mouse->isMaster && type == LeaveNotify &&
-    {
+            (mode != NotifyVirtual && mode != NotifyNonlinearVirtual))
-        if (((*inWindow) == (LeaveNotify - type)))
+        ENTER_LEAVE_SEMAPHORE_UNSET(pWin, mouse);
-            sendevent = TRUE;
+
-    } else
+    inWindow = EnterLeaveSemaphoresIsset(pWin);
-    {
+
-        if (!(*inWindow))
+    if (!inWindow)
-            sendevent = TRUE;
+        sendevent = TRUE;
-    }
 
     if ((mask & filters[mouse->id][type]) && sendevent)
     {
@@ -4493,6 +4491,10 @@ EnterLeaveEvent(
                                   filters[mouse->id][type], NullGrab, 0);
     }
 
+    if (mouse->isMaster && type == EnterNotify &&
+            (mode != NotifyVirtual && mode != NotifyNonlinearVirtual))
+        ENTER_LEAVE_SEMAPHORE_SET(pWin, mouse);
+
     /* we don't have enough bytes, so we squash flags and mode into
        one byte, and use the last byte for the deviceid. */
     devEnterLeave = (deviceEnterNotify*)&event;
@@ -4582,25 +4584,6 @@ LeaveNotifies(DeviceIntPtr pDev,
     }
 }
 
-/* welcome to insanity */
-#define FOCUS_SEMAPHORE_MODIFY(win, field, mode, val) \
-{ \
-    FocusSemaphoresPtr sem;\
-    sem = (FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey); \
-    if (mode != NotifyGrab && mode != NotifyUngrab) { \
-        sem->field += val; \
-    } else if (mode == NotifyUngrab) { \
-        if (sem->field == 0 && val > 0) \
-            sem->field += val; \
-        else if (sem->field == 1 && val < 0) \
-            sem->field += val; \
-    } \
-}
-#define ENTER_LEAVE_SEMAPHORE_UP(win, mode)  \
-        FOCUS_SEMAPHORE_MODIFY(win, enterleave, mode, 1);
-
-#define ENTER_LEAVE_SEMAPHORE_DOWN(win, mode) \
-        FOCUS_SEMAPHORE_MODIFY(win, enterleave, mode,  -1);
 
 
 /**
@@ -4620,33 +4603,27 @@ DoEnterLeaveEvents(DeviceIntPtr pDev,
 	return;
     if (IsParent(fromWin, toWin))
     {
-        ENTER_LEAVE_SEMAPHORE_DOWN(fromWin, mode);
         EnterLeaveEvent(pDev, LeaveNotify, mode, NotifyInferior, fromWin,
                         None);
         EnterNotifies(pDev, fromWin, toWin, mode,
                       NotifyVirtual);
-        ENTER_LEAVE_SEMAPHORE_UP(toWin, mode);
         EnterLeaveEvent(pDev, EnterNotify, mode, NotifyAncestor, toWin, None);
     }
     else if (IsParent(toWin, fromWin))
     {
-        ENTER_LEAVE_SEMAPHORE_DOWN(fromWin, mode);
 	EnterLeaveEvent(pDev, LeaveNotify, mode, NotifyAncestor, fromWin,
                         None);
 	LeaveNotifies(pDev, fromWin, toWin, mode, NotifyVirtual);
-        ENTER_LEAVE_SEMAPHORE_UP(toWin, mode);
 	EnterLeaveEvent(pDev, EnterNotify, mode, NotifyInferior, toWin, None);
     }
     else
     { /* neither fromWin nor toWin is descendent of the other */
 	WindowPtr common = CommonAncestor(toWin, fromWin);
 	/* common == NullWindow ==> different screens */
-        ENTER_LEAVE_SEMAPHORE_DOWN(fromWin, mode);
         EnterLeaveEvent(pDev, LeaveNotify, mode, NotifyNonlinear, fromWin,
                         None);
         LeaveNotifies(pDev, fromWin, common, mode, NotifyNonlinearVirtual);
 	EnterNotifies(pDev, common, toWin, mode, NotifyNonlinearVirtual);
-        ENTER_LEAVE_SEMAPHORE_UP(toWin, mode);
         EnterLeaveEvent(pDev, EnterNotify, mode, NotifyNonlinear, toWin,
                         None);
     }
@@ -4656,7 +4633,7 @@ static void
 FocusEvent(DeviceIntPtr dev, int type, int mode, int detail, WindowPtr pWin)
 {
     xEvent event;
-    int* numFoci; /* no of foci the window has already */
+    int numFoci; /* zero if no device has focus on window */
     Bool sendevent = FALSE;
 
     if (dev != inputInfo.keyboard)
@@ -4690,25 +4667,18 @@ FocusEvent(DeviceIntPtr dev, int type, int mode, int detail, WindowPtr pWin)
      * NotifyNonlinearVirtual to C and nothing to B.
      */
 
-    numFoci =
+    if (dev->isMaster && type == FocusOut &&
-        &((FocusSemaphoresPtr)dixLookupPrivate(&pWin->devPrivates,
+            (detail != NotifyVirtual &&
-                    FocusPrivatesKey))->focusinout;
+             detail != NotifyNonlinearVirtual &&
-    if (mode == NotifyGrab || mode == NotifyUngrab)
+             detail != NotifyPointer &&
+             detail != NotifyPointerRoot &&
+             detail != NotifyDetailNone))
+       FOCUS_SEMAPHORE_UNSET(pWin, dev);
+
+    numFoci = FocusSemaphoresIsset(pWin);
+
+    if (!numFoci)
         sendevent = TRUE;
-    else if (detail != NotifyVirtual &&
-            detail != NotifyNonlinearVirtual &&
-            detail != NotifyPointer &&
-            detail != NotifyPointerRoot &&
-            detail != NotifyDetailNone)
-    {
-        (type == FocusIn) ? (*numFoci)++ : (*numFoci)--;
-        if (((*numFoci) == (FocusOut - type)))
-            sendevent = TRUE;
-    } else
-    {
-        if (!(*numFoci))
-            sendevent = TRUE;
-    }
 
     if (sendevent)
     {
@@ -4733,6 +4703,14 @@ FocusEvent(DeviceIntPtr dev, int type, int mode, int detail, WindowPtr pWin)
                                         KeymapStateMask, NullGrab, 0);
         }
     }
+
+    if (dev->isMaster && type == FocusIn &&
+            (detail != NotifyVirtual &&
+             detail != NotifyNonlinearVirtual &&
+             detail != NotifyPointer &&
+             detail != NotifyPointerRoot &&
+             detail != NotifyDetailNone))
+        FOCUS_SEMAPHORE_SET(pWin, dev);
 }
 
  /*
@@ -6616,3 +6594,37 @@ ExtGrabDevice(ClientPtr client,
     return GrabSuccess;
 }
 
+/*
+ * @return Zero if no device is currently in window, non-zero otherwise.
+ */
+int
+EnterLeaveSemaphoresIsset(WindowPtr win)
+{
+    FocusSemaphoresPtr sem;
+    int set = 0;
+    int i;
+
+    sem = (FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey);
+    for (i = 0; i < (MAX_DEVICES + 7)/8; i++)
+        set += sem->enterleave[i];
+
+    return set;
+}
+
+/*
+ * @return Zero if no devices has focus on the window, non-zero otherwise.
+ */
+int
+FocusSemaphoresIsset(WindowPtr win)
+{
+    FocusSemaphoresPtr sem;
+    int set = 0;
+    int i;
+
+    sem = (FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey);
+    for (i = 0; i < (MAX_DEVICES + 7)/8; i++)
+        set += sem->focusinout[i];
+
+    return set;
+}
+

dix/window.c

@@ -366,6 +366,7 @@ CreateRootWindow(ScreenPtr pScreen)
     WindowPtr	pWin;
     BoxRec	box;
     PixmapFormatRec *format;
+    FocusSemaphoresPtr sem;
 
     pWin = (WindowPtr)xalloc(sizeof(WindowRec));
     if (!pWin)
@@ -484,6 +485,7 @@ CreateRootWindow(ScreenPtr pScreen)
 		
     if (disableSaveUnders)
 	pScreen->saveUnderSupport = NotUseful;
+
     return TRUE;
 }
 

include/input.h

@@ -80,6 +80,39 @@ SOFTWARE.
 #define RevertToFollowKeyboard	3
 #endif
 
+/* Used for enter/leave and focus in/out semaphores */
+#define SEMAPHORE_FIELD_SET(win, dev, field) \
+{ \
+    FocusSemaphoresPtr sem; \
+    sem = (FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey); \
+    sem->field[dev->id/8] |= (1 << (dev->id % 8)); \
+}
+
+#define SEMAPHORE_FIELD_UNSET(win, dev, field) \
+{ \
+    FocusSemaphoresPtr sem; \
+    sem = (FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey); \
+    sem->field[dev->id/8] &= ~(1 << (dev->id % 8)); \
+}
+
+#define ENTER_LEAVE_SEMAPHORE_SET(win, dev) \
+        SEMAPHORE_FIELD_SET(win, dev, enterleave);
+
+#define ENTER_LEAVE_SEMAPHORE_UNSET(win, dev) \
+        SEMAPHORE_FIELD_UNSET(win, dev, enterleave);
+
+#define ENTER_LEAVE_SEMAPHORE_ISSET(win, dev) \
+    ((FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey))->enterleave[dev->id/8] & (1 << (dev->id % 8))
+
+#define FOCUS_SEMAPHORE_SET(win, dev) \
+        SEMAPHORE_FIELD_SET(win, dev, focusinout);
+
+#define FOCUS_SEMAPHORE_UNSET(win, dev) \
+        SEMAPHORE_FIELD_UNSET(win, dev, focusinout);
+
+#define FOCUS_SEMAPHORE_ISSET(win, dev) \
+    ((FocusSemaphoresPtr)dixLookupPrivate(&win->devPrivates, FocusPrivatesKey))->focusinout[dev->id/8] & (1 << (dev->id % 8))
+
 typedef unsigned long Leds;
 typedef struct _OtherClients *OtherClientsPtr;
 typedef struct _InputClients *InputClientsPtr;
@@ -488,6 +521,8 @@ extern void DeepCopyDeviceClasses(DeviceIntPtr from,
 extern void FreeDeviceClass(int type, pointer* class);
 extern void FreeFeedbackClass(int type, pointer* class);
 extern void FreeAllDeviceClasses(ClassesPtr classes);
+extern int EnterLeaveSemaphoresIsset(WindowPtr win);
+extern int FocusSemaphoresIsset(WindowPtr win);
 
 /* Window/device based access control */
 extern Bool ACRegisterClient(ClientPtr client);

include/windowstr.h

@@ -59,6 +59,7 @@ SOFTWARE.
 #include "miscstruct.h"
 #include <X11/Xprotostr.h>
 #include "opaque.h"
+#include "inputstr.h"
 
 #define GuaranteeNothing	0
 #define GuaranteeVisBack	1
@@ -257,11 +258,14 @@ extern ScreenSaverStuffRec savedScreenInfo[MAXSCREENS];
 extern DevPrivateKey FocusPrivatesKey;
 
 /* Used to maintain semantics of core protocol for Enter/LeaveNotifies and
- * FocusIn/Out events for multiple pointers/keyboards. 
+ * FocusIn/Out events for multiple pointers/keyboards.
- */ 
+ *
+ * Each device ID corresponds to one bit. If set, the device is in the
+ * window/has focus.
+ */
 typedef struct _FocusSemaphores {
-    int                 enterleave;
+    char                enterleave[(MAX_DEVICES + 7)/8];
-    int                 focusinout;
+    char                focusinout[(MAX_DEVICES + 7)/8];
 } FocusSemaphoresRec, *FocusSemaphoresPtr;
 
 /*