faster X11 server polling (b1236a9 + 6988d58)

xpra/x11/bindings/wait_for_x_server.pyx

@@ -26,15 +26,18 @@ cdef extern from "X11/Xlib.h":
 def wait_for_x_server(display_name, int timeout):
     cdef Display * d
     cdef char* name
+    if display_name is not None:
+        name = display_name
+    else:
+        name = NULL
+    t = 100
     cdef double start = monotonic_time()
-    name = display_name
-    first_time = True
-    while first_time or (monotonic_time() - start) < timeout:
-        if not first_time:
-            sleep(0.2)
-        first_time = False
+    while (monotonic_time() - start) < timeout:
         d = XOpenDisplay(name)
         if d is not NULL:
             XCloseDisplay(d)
             return
+        if t>0:
+            sleep(t/1000)
+            t = t//2
     raise RuntimeError("could not connect to X server on display '%s' after %i seconds" % (bytestostr(display_name), timeout))