dix: Reallocate touchpoint buffer at input event time [v2]

Now that input is threaded, malloc can be used at event time to resize
the touchpoint buffer as needed.x

v2: Remove "Need to grow the queue means dropping events."
    from comment as it no longer applies. (Peter Hutterer)

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

dix/touch.c

@@ -42,9 +42,6 @@
 
 #define TOUCH_HISTORY_SIZE 100
 
-/* If a touch queue resize is needed, the device id's bit is set. */
-static unsigned char resize_waiting[(MAXDEVICES + 7) / 8];
-
 /**
  * Some documentation about touch points:
  * The driver submits touch events with it's own (unique) touch point ID.
@@ -74,31 +71,14 @@ static unsigned char resize_waiting[(MAXDEVICES + 7) / 8];
  * @return Always True. If we fail to grow we probably will topple over soon
  * anyway and re-executing this won't help.
  */
+
 static Bool
-TouchResizeQueue(ClientPtr client, void *closure)
+TouchResizeQueue(DeviceIntPtr dev)
 {
-    int i;
-
-    input_lock();
-
-    /* first two ids are reserved */
-    for (i = 2; i < MAXDEVICES; i++) {
-        DeviceIntPtr dev;
     DDXTouchPointInfoPtr tmp;
     size_t size;
 
-        if (!BitIsOn(resize_waiting, i))
+    /* Grow sufficiently so we don't need to do it often */
-            continue;
-
-        ClearBit(resize_waiting, i);
-
-        /* device may have disappeared by now */
-        dixLookupDevice(&dev, i, serverClient, DixWriteAccess);
-        if (!dev)
-            continue;
-
-        /* Need to grow the queue means dropping events. Grow sufficiently so we
-         * don't need to do it often */
     size = dev->last.num_touches + dev->last.num_touches / 2 + 1;
 
     tmp = reallocarray(dev->last.touches, size, sizeof(*dev->last.touches));
@@ -109,12 +89,9 @@ TouchResizeQueue(ClientPtr client, void *closure)
         for (j = dev->last.num_touches; j < size; j++)
             TouchInitDDXTouchPoint(dev, &dev->last.touches[j]);
         dev->last.num_touches = size;
-        }
-
-    }
-    input_unlock();
-
         return TRUE;
+    }
+    return FALSE;
 }
 
 /**
@@ -172,6 +149,7 @@ TouchBeginDDXTouch(DeviceIntPtr dev, uint32_t ddx_id)
     if (TouchFindByDDXID(dev, ddx_id, FALSE))
         return NULL;
 
+    for (;;) {
         for (i = 0; i < dev->last.num_touches; i++) {
             /* Only emulate pointer events on the first touch */
             if (dev->last.touches[i].active)
@@ -182,6 +160,11 @@ TouchBeginDDXTouch(DeviceIntPtr dev, uint32_t ddx_id)
             if (!emulate_pointer && ti)
                 break;
         }
+        if (ti)
+            break;
+        if (!TouchResizeQueue(dev))
+            break;
+    }
 
     if (ti) {
         int client_id;
@@ -194,21 +177,8 @@ TouchBeginDDXTouch(DeviceIntPtr dev, uint32_t ddx_id)
             next_client_id = 1;
         ti->client_id = client_id;
         ti->emulate_pointer = emulate_pointer;
+    }
     return ti;
-    }
-
-    /* If we get here, then we've run out of touches and we need to drop the
-     * event (we're inside the SIGIO handler here) schedule a WorkProc to
-     * grow the queue for us for next time. */
-    ErrorFSigSafe("%s: not enough space for touch events (max %u touchpoints). "
-                  "Dropping this event.\n", dev->name, dev->last.num_touches);
-
-    if (!BitIsOn(resize_waiting, dev->id)) {
-        SetBit(resize_waiting, dev->id);
-        QueueWorkProc(TouchResizeQueue, serverClient, NULL);
-    }
-
-    return NULL;
 }
 
 void