[pango] Improve test-pangocairo-threads

[Behdad Esfahbod <behdad src gnome org>]

commit 080c1eaf78e0d4eff2c81720a750845bad47c709
Author: Behdad Esfahbod <behdad behdad org>
Date:   Fri Jan 4 00:38:17 2013 -0600

    Improve test-pangocairo-threads
    
    Can be run standalone now, compares the output of all threads and fails
    if they mismatch.

 tests/test-pangocairo-threads.c |   62 ++++++++++++++++++++++++++++++--------
 1 files changed, 49 insertions(+), 13 deletions(-)
---
diff --git a/tests/test-pangocairo-threads.c b/tests/test-pangocairo-threads.c
index 97d5dfe..6242839 100644
--- a/tests/test-pangocairo-threads.c
+++ b/tests/test-pangocairo-threads.c
@@ -1,18 +1,27 @@
 #include <stdlib.h>
+#include <string.h>
 #include <pango/pango.h>
 #include <pango/pangocairo.h>
 
+#define WIDTH 100
+#define HEIGHT 100
 const char *text = "The quick brown fox jumped over the lazy dog!";
 int num_iters = 100;
 
 GMutex mutex;
 
+static cairo_surface_t *
+create_surface (void)
+{
+  return cairo_image_surface_create (CAIRO_FORMAT_A8, WIDTH, HEIGHT);
+}
+
 static PangoLayout *
 create_layout (cairo_t *cr)
 {
   PangoLayout *layout = pango_cairo_create_layout (cr);
   pango_layout_set_text (layout, text, -1);
-  pango_layout_set_width (layout, 100 * PANGO_SCALE);
+  pango_layout_set_width (layout, WIDTH * PANGO_SCALE);
   return layout;
 }
 
@@ -33,12 +42,10 @@ draw (cairo_t *cr, PangoLayout *layout)
 static gpointer
 thread_func (gpointer data)
 {
-  int num = GPOINTER_TO_INT (data);
-  int i;
-  char *filename;
+  cairo_surface_t *surface = data;
   PangoLayout *layout;
+  int i;
 
-  cairo_surface_t *surface = cairo_image_surface_create (CAIRO_FORMAT_A8, 100, 100);
   cairo_t *cr = cairo_create (surface);
 
   layout = create_layout (cr);
@@ -49,10 +56,6 @@ thread_func (gpointer data)
   for (i = 0; i < num_iters; i++)
     draw (cr, layout);
 
-  filename = g_strdup_printf ("%d.png", num);
-  cairo_surface_write_to_png (surface, filename);
-  g_free (filename);
-
   return 0;
 }
 
@@ -62,6 +65,7 @@ main (int argc, char **argv)
   int num_threads = 2;
   int i;
   GPtrArray *threads = g_ptr_array_new ();
+  GPtrArray *surfaces = g_ptr_array_new ();
 
   if (argc > 1)
     num_threads = atoi (argv[1]);
@@ -71,10 +75,14 @@ main (int argc, char **argv)
   g_mutex_lock (&mutex);
 
   for (i = 0; i < num_threads; i++)
-    g_ptr_array_add (threads,
-		     g_thread_new (g_strdup_printf ("%d", i + 1),
-				   thread_func,
-				   GINT_TO_POINTER (i+1)));
+    {
+      cairo_surface_t *surface = create_surface ();
+      g_ptr_array_add (surfaces, surface);
+      g_ptr_array_add (threads,
+		       g_thread_new (g_strdup_printf ("%d", i),
+				     thread_func,
+				     surface));
+    }
 
   /* Let them loose! */
   g_mutex_unlock (&mutex);
@@ -82,5 +90,33 @@ main (int argc, char **argv)
   for (i = 0; i < num_threads; i++)
     g_thread_join (g_ptr_array_index (threads, i));
 
+  /* Now, draw a reference image and check results. */
+  {
+    cairo_surface_t *ref_surface = create_surface ();
+    cairo_t *cr = cairo_create (ref_surface);
+    PangoLayout *layout = create_layout (cr);
+    unsigned char *ref_data = cairo_image_surface_get_data (ref_surface);
+    unsigned int len = WIDTH * HEIGHT;
+
+    draw (cr, layout);
+
+    /* cairo_surface_write_to_png (ref_surface, "test-pangocairo-threads-reference.png"); */
+
+    g_assert (WIDTH == cairo_format_stride_for_width (CAIRO_FORMAT_A8, WIDTH));
+
+    for (i = 0; i < num_threads; i++)
+      {
+	cairo_surface_t *surface = g_ptr_array_index (surfaces, i);
+	unsigned char *data = cairo_image_surface_get_data (surface);
+	if (memcmp (ref_data, data, len))
+	  {
+	    fprintf (stderr, "image for thread %d different from reference image.\n", i);
+	    cairo_surface_write_to_png (ref_surface, "test-pangocairo-threads-reference.png");
+	    cairo_surface_write_to_png (surface, "test-pangocairo-threads-failed.png");
+	    return 1;
+	  }
+      }
+  }
+
   return 0;
 }