From e43cc9c9024957dcc7f160f6abe7be218667dfa2 Mon Sep 17 00:00:00 2001 From: Siarhei Siamashka Date: Thu, 5 Sep 2013 08:07:52 +0300 Subject: [PATCH] test: safeguard the scaling-bench test against COW The calloc call from pixman_image_create_bits may still rely on http://en.wikipedia.org/wiki/Copy-on-write Explicitly initializing the destination image results in a more predictable behaviour. V2: - allocate 16 bytes aligned buffer with aligned stride instead of delegating this to pixman_image_create_bits - use memset for the allocated buffer instead of pixman solid fill - repeat tests 3 times and select best results in order to filter out even more measurement noise --- test/scaling-bench.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/test/scaling-bench.c b/test/scaling-bench.c index b39adef..365e798 100644 --- a/test/scaling-bench.c +++ b/test/scaling-bench.c @@ -3,6 +3,7 @@ #define SOURCE_WIDTH 320 #define SOURCE_HEIGHT 240 +#define TEST_REPEATS 3 static pixman_image_t * make_source (void) @@ -39,30 +40,40 @@ main () "time per pixel / ns"); for (scale = 0.1; scale < 10.005; scale += 0.01) { + int i; int dest_width = SOURCE_WIDTH * scale + 0.5; int dest_height = SOURCE_HEIGHT * scale + 0.5; + int dest_byte_stride = (dest_width * 4 + 15) & ~15; pixman_fixed_t s = (1 / scale) * 65536.0 + 0.5; pixman_transform_t transform; pixman_image_t *dest; - double t1, t2; + double t1, t2, t = -1; + uint32_t *dest_buf = aligned_malloc (16, dest_byte_stride * dest_height); + memset (dest_buf, 0, dest_byte_stride * dest_height); pixman_transform_init_scale (&transform, s, s); pixman_image_set_transform (src, &transform); dest = pixman_image_create_bits ( - PIXMAN_a8r8g8b8, dest_width, dest_height, NULL, -1); + PIXMAN_a8r8g8b8, dest_width, dest_height, dest_buf, dest_byte_stride); + + for (i = 0; i < TEST_REPEATS; i++) + { + t1 = gettime(); + pixman_image_composite ( + PIXMAN_OP_OVER, src, NULL, dest, + scale, scale, 0, 0, 0, 0, dest_width, dest_height); + t2 = gettime(); + if (t < 0 || t2 - t1 < t) + t = t2 - t1; + } - t1 = gettime(); - pixman_image_composite ( - PIXMAN_OP_OVER, src, NULL, dest, - scale, scale, 0, 0, 0, 0, dest_width, dest_height); - t2 = gettime(); - printf ("%6.2f : %4dx%-4d => %4dx%-4d : %12.4f : %12.4f\n", scale, SOURCE_WIDTH, SOURCE_HEIGHT, dest_width, dest_height, - (t2 - t1) * 1000, ((t2 - t1) / (dest_width * dest_height)) * 1000000000); + t * 1000, (t / (dest_width * dest_height)) * 1000000000); pixman_image_unref (dest); + free (dest_buf); } return 0; -- 2.7.4