perf: Make xlib testing wait for the X server to finish rendering.

We do this by adding a new cairo_perf_timer_set_finalize function and
in the case of the xlib backend passing a callback to that function
that does a 1x1 XGetImage.

boilerplate/cairo-boilerplate.c

@@ -919,6 +919,17 @@ typedef struct _xlib_target_closure
     cairo_bool_t drawable_is_pixmap;
 } xlib_target_closure_t;
 
+static void
+boilerplate_xlib_wait_for_rendering (void *closure)
+{
+    xlib_target_closure_t *xtc = closure;
+    XImage *ximage;
+
+    ximage = XGetImage (xtc->dpy, xtc->drawable,
+			0, 0, 1, 1, AllPlanes, ZPixmap);
+    XDestroyImage (ximage);
+}
+
 /* For the xlib backend we distinguish between TEST and PERF mode in a
  * couple of ways.
  *
@@ -1478,9 +1489,11 @@ cairo_boilerplate_target_t targets[] =
 #endif
 #if CAIRO_HAS_XLIB_SURFACE
     { "xlib", CAIRO_SURFACE_TYPE_XLIB, CAIRO_CONTENT_COLOR_ALPHA, 0,
-      create_xlib_surface, cairo_surface_write_to_png, cleanup_xlib},
+      create_xlib_surface, cairo_surface_write_to_png, cleanup_xlib,
+      boilerplate_xlib_wait_for_rendering},
     { "xlib", CAIRO_SURFACE_TYPE_XLIB, CAIRO_CONTENT_COLOR, 0,
-      create_xlib_surface, cairo_surface_write_to_png, cleanup_xlib},
+      create_xlib_surface, cairo_surface_write_to_png, cleanup_xlib,
+      boilerplate_xlib_wait_for_rendering},
 #endif
 #if CAIRO_HAS_PS_SURFACE
     { "ps", CAIRO_SURFACE_TYPE_PS,

boilerplate/cairo-boilerplate.h

@@ -107,6 +107,9 @@ typedef cairo_status_t
 typedef void
 (*cairo_boilerplate_cleanup_t) (void *closure);
 
+typedef void
+(*cairo_boilerplate_wait_t) (void *closure);
+
 typedef struct _cairo_boilerplate_target
 {
     const char		       	       *name;
@@ -116,6 +119,7 @@ typedef struct _cairo_boilerplate_target
     cairo_boilerplate_create_surface_t	create_surface;
     cairo_boilerplate_write_to_png_t	write_to_png;
     cairo_boilerplate_cleanup_t		cleanup;
+    cairo_boilerplate_wait_t		wait_for_rendering;
     void			       *closure;
 } cairo_boilerplate_target_t;
 

perf/cairo-perf-posix.c

@@ -130,8 +130,20 @@ cairo_perf_timer_start (void) {
 #endif
 }
 
+static cairo_perf_timer_finalize_t cairo_perf_timer_finalize = NULL;
+static void *cairo_perf_timer_finalize_closure = NULL;
+void
+cairo_perf_timer_set_finalize (cairo_perf_timer_finalize_t	 finalize,
+			       void				*closure)
+{
+    cairo_perf_timer_finalize = finalize;
+    cairo_perf_timer_finalize_closure = closure;
+}
+
 void
 cairo_perf_timer_stop (void) {
+    if (cairo_perf_timer_finalize)
+	cairo_perf_timer_finalize (cairo_perf_timer_finalize_closure);
 #ifdef OIL_STAMP
     timer.stop = OIL_STAMP ();
 #else

perf/cairo-perf.c

@@ -162,6 +162,7 @@ main (int argc, char *argv[])
 						    size, size,
 						    CAIRO_BOILERPLATE_MODE_PERF,
 						    &target->closure);
+		cairo_perf_timer_set_finalize (target->wait_for_rendering, target->closure);
 		cr = cairo_create (surface);
 		for (k =0; k < cairo_perf_iterations; k++) {
 		    cairo_perf_yield ();

perf/cairo-perf.h

@@ -38,6 +38,13 @@ cairo_perf_timer_start (void);
 void
 cairo_perf_timer_stop (void);
 
+typedef void
+(*cairo_perf_timer_finalize_t) (void *closure);
+
+void
+cairo_perf_timer_set_finalize (cairo_perf_timer_finalize_t	 finalize,
+			       void				*closure);
+
 typedef uint64_t cairo_perf_ticks_t;
 
 cairo_perf_ticks_t