[Piglit] [PATCH 7/9] Validate that OML Sync Control syncs to vblank.

Jamey Sharp jamey at minilop.net
Wed Apr 23 17:27:21 PDT 2014


From: TheoH <Theo0x48 at gmail.com>

The existing tests don't demonstrate a variety of implementation bugs
that we've observed in current drivers, so this is our attempt to
demonstrate those bugs.

Signed-off-by: Theo Hill <Theo0x48 at gmail.com>
Signed-off-by: Jamey Sharp <jamey at minilop.net>
---
 tests/all.py                                      |   9 +
 tests/spec/glx_oml_sync_control/CMakeLists.gl.txt |   1 +
 tests/spec/glx_oml_sync_control/timing.c          | 298 ++++++++++++++++++++++
 3 files changed, 308 insertions(+)
 create mode 100644 tests/spec/glx_oml_sync_control/timing.c

diff --git a/tests/all.py b/tests/all.py
index ccfa626..d610ce0 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -786,6 +786,15 @@ oml_sync_control['swapbuffersmsc-return swap_interval 0'] = PiglitTest(['glx-oml
 oml_sync_control['swapbuffersmsc-return swap_interval 1'] = PiglitTest(['glx-oml-sync-control-swapbuffersmsc-return', '1'])
 oml_sync_control['waitformsc'] = PiglitTest(['glx-oml-sync-control-waitformsc'])
 
+oml_sync_control_nonzeros = [
+    mode + [kind, period]
+    for mode in [[], ['-fullscreen'], ['-waitformsc']]
+    for kind in ['-divisor', '-msc-delta']
+    for period in ['1', '2']
+]
+for arg in [[], ['-fullscreen']] + oml_sync_control_nonzeros:
+    oml_sync_control[' '.join(['timing'] + arg)] = PiglitTest(['glx-oml-sync-control-timing'] + arg)
+
 mesa_query_renderer = {}
 glx['GLX_MESA_query_renderer'] = mesa_query_renderer
 mesa_query_renderer['coverage'] = concurrent_test('glx-query-renderer-coverage')
diff --git a/tests/spec/glx_oml_sync_control/CMakeLists.gl.txt b/tests/spec/glx_oml_sync_control/CMakeLists.gl.txt
index c299848..125e2a5 100644
--- a/tests/spec/glx_oml_sync_control/CMakeLists.gl.txt
+++ b/tests/spec/glx_oml_sync_control/CMakeLists.gl.txt
@@ -26,6 +26,7 @@ IF(PIGLIT_BUILD_GLX_TESTS)
 	piglit_add_executable (glx-oml-sync-control-swapbuffersmsc-divisor-zero swapbuffersmsc-divisor-zero.c common.c)
 	piglit_add_executable (glx-oml-sync-control-swapbuffersmsc-return swapbuffersmsc-return.c common.c)
 	piglit_add_executable (glx-oml-sync-control-waitformsc waitformsc.c common.c)
+	piglit_add_executable (glx-oml-sync-control-timing timing.c common.c)
 ENDIF(PIGLIT_BUILD_GLX_TESTS)
 
 # vim: ft=cmake:
diff --git a/tests/spec/glx_oml_sync_control/timing.c b/tests/spec/glx_oml_sync_control/timing.c
new file mode 100644
index 0000000..decb352
--- /dev/null
+++ b/tests/spec/glx_oml_sync_control/timing.c
@@ -0,0 +1,298 @@
+/*
+ * Copyright © 2014 The TOVA Company
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/**
+ * \file timing.c
+ * Validates that OML Sync Control implementation actually syncs to vertical retrace
+ */
+
+#include "piglit-util-gl-common.h"
+#include "piglit-glx-util.h"
+#include "common.h"
+/*
+ * TODO: varying MSC deltas enumerated as arguments
+ * TODO: As a different test, create two drawables and verify they have independent SBC
+ */
+static bool fullscreen;
+static bool use_swapbuffers = true;
+static int64_t target_msc_delta;
+static int64_t divisor;
+static const int64_t msc_remainder = 0;
+static const unsigned int loops = 10;
+
+struct stats {
+	unsigned int n;
+	double mean;
+	double M2;
+};
+
+static void update_stats(struct stats *stats, double val) {
+	double delta = val - stats->mean;
+	stats->n += 1;
+	stats->mean += delta / stats->n;
+	stats->M2 += delta * (val - stats->mean);
+}
+
+static double get_stddev(struct stats *stats) {
+	return sqrt(stats->M2 / (stats->n - 1));
+}
+
+static enum piglit_result
+draw(Display *dpy)
+{
+	enum piglit_result result = PIGLIT_PASS;
+	int64_t last_ust = 0xd0, last_msc = 0xd0, last_sbc = 0xd0, last_timestamp = -1;
+	struct stats msc_wallclock_duration_stats = {};
+	struct stats msc_ust_duration_stats = {};
+	double expected_msc_wallclock_duration = 0.0;
+	int32_t rate_num, rate_den;
+	unsigned int i;
+
+	if (!glXGetSyncValuesOML(dpy, win, &last_ust, &last_msc, &last_sbc)) {
+		fprintf(stderr, "Initial glXGetSyncValuesOML failed\n");
+		return PIGLIT_FAIL;
+	}
+
+	/* Check that the window is fresh */
+	if (last_sbc != 0) {
+		fprintf(stderr, "Initial SBC for the window should be 0, was %" PRId64 "\n", last_sbc);
+	}
+
+	if (!glXGetMscRateOML(dpy, win, &rate_num, &rate_den)) {
+		fprintf(stderr, "glXGetMscRateOML failed, can't test MSC duration\n");
+	} else {
+		expected_msc_wallclock_duration = 1e6 * rate_den / rate_num;
+	}
+
+	for (i = 0; i < loops; i++) {
+		int64_t swapped_ust = 0xd0, swapped_msc = 0xd0, swapped_sbc = 0xd0;
+		int64_t new_ust = 0xd0, new_msc = 0xd0, new_sbc = 0xd0, new_timestamp;
+		int64_t expected_msc, target_sbc;
+		int64_t target_msc = 0;
+
+		if (target_msc_delta) {
+			target_msc = last_msc + target_msc_delta;
+		}
+
+		if (use_swapbuffers) {
+			glClearColor(0.0, 1.0, 0.0, 0.0);
+			glClear(GL_COLOR_BUFFER_BIT);
+			glFlush();
+
+			target_sbc = glXSwapBuffersMscOML(dpy, win, target_msc, divisor, msc_remainder);
+			if(target_sbc <= 0) {
+				fprintf(stderr, "glXSwapBuffersMscOML failed\n");
+				return PIGLIT_FAIL;
+			}
+                        /*ERROR: swapBuffersMsc calculates wrong target SBC (i.e. not current sbc + 1) */
+			if(target_sbc != last_sbc + 1) {
+				fprintf(stderr, "glXSwapBuffersMscOML calculated the wrong target sbc: expected %"PRId64" but got %"PRId64"\n", last_sbc + 1, target_sbc);
+				result = PIGLIT_FAIL;
+			}
+
+			if(!glXWaitForSbcOML(dpy, win, target_sbc, &swapped_ust, &swapped_msc, &swapped_sbc)) {
+				fprintf(stderr, "glXWaitForSbcOML failed\n");
+				result = PIGLIT_FAIL;
+			}
+		} else {
+			target_sbc = last_sbc;
+
+			if(!glXWaitForMscOML(dpy, win, target_msc, divisor, msc_remainder, &swapped_ust, &swapped_msc, &swapped_sbc)) {
+				fprintf(stderr, "glXWaitForSbcOML failed\n");
+				result = PIGLIT_FAIL;
+			}
+		}
+		new_timestamp = piglit_get_microseconds();
+
+		if (!glXGetSyncValuesOML(dpy, win, &new_ust, &new_msc, &new_sbc)) {
+			fprintf(stderr, "Follow-up glXGetSyncValuesOML failed\n");
+			return PIGLIT_FAIL;
+		}
+
+		/* ERROR: immediately after waitForMsc or waitForSbc, getSyncValues returns different ust/msc/sbc */
+		if (swapped_ust != new_ust) {
+			fprintf(stderr, "glXGetSyncValuesOML returned UST %"PRId64" but Wait returned %"PRId64"\n", new_ust, swapped_ust);
+			result = PIGLIT_FAIL;
+		}
+
+		if (swapped_msc != new_msc) {
+			fprintf(stderr, "glXGetSyncValuesOML returned MSC %"PRId64" but Wait returned %"PRId64"\n", new_msc, swapped_msc);
+			result = PIGLIT_FAIL;
+		}
+
+		if (swapped_sbc != new_sbc) {
+			fprintf(stderr, "glXGetSyncValuesOML returned SBC %"PRId64" but Wait returned %"PRId64"\n", new_sbc, swapped_sbc);
+			result = PIGLIT_FAIL;
+		}
+
+		if (new_msc > last_msc) {
+			int64_t delta_msc = new_msc - last_msc;
+			update_stats(&msc_ust_duration_stats, (new_ust - last_ust) / delta_msc);
+
+			if (last_timestamp >= 0) {
+				if (new_timestamp < 0) {
+					fprintf(stderr, "no monotonic clock available\n");
+				} else {
+					update_stats(&msc_wallclock_duration_stats, (new_timestamp - last_timestamp) / delta_msc);
+				}
+			}
+		}
+
+		/* ERROR: non-monotonicity in ust/msc */
+		if (new_ust < last_ust) {
+			fprintf(stderr, "non-monotonic UST went backward by %"PRId64"\n", last_ust - new_ust);
+			result = PIGLIT_FAIL;
+		}
+
+		if (new_msc < last_msc) {
+			fprintf(stderr, "non-monotonic MSC went backward by %"PRId64"\n", last_msc - new_msc);
+			result = PIGLIT_FAIL;
+		}
+
+		/* ERROR: waitForSbc returns on the wrong SBC or waitForMsc changes SBC */
+		if (new_sbc != target_sbc) {
+			fprintf(stderr, "Wait should have returned at SBC %"PRId64" but returned at %"PRId64"\n", target_sbc, new_sbc);
+			result = PIGLIT_FAIL;
+		}
+
+		/* ERROR: Wake up MSC too early */
+		/* WARNING: MSC is late. Technically being late is allowed by the spec */
+		expected_msc = target_msc;
+		if (divisor) {
+			/* If there is a divisor, the expected MSC is the next MSC after last_msc such that MSC % divisor == remainder */
+			int64_t last_remainder = last_msc % divisor;
+			expected_msc = last_msc - last_remainder + msc_remainder;
+			if (expected_msc <= last_msc)
+				expected_msc += divisor;
+		} else if (!target_msc) {
+			expected_msc = last_msc + 1;
+		}
+
+		if (new_msc < expected_msc) {
+			fprintf(stderr, "woke up %"PRId64" MSCs early\n", expected_msc - new_msc);
+			result = PIGLIT_FAIL;
+		}
+
+		if (new_msc > expected_msc) {
+			fprintf(stderr, "woke up %"PRId64" MSCs later than expected\n", new_msc - expected_msc);
+		}
+
+		/* ERROR: if divisor is non-0 and MSC % divisor != remainder */
+		if (divisor && new_msc % divisor != msc_remainder) {
+			fprintf(stderr, "woke up at wrong MSC remainder %"PRId64", not requested remainder %"PRId64"\n", new_msc % divisor, msc_remainder);
+			result = PIGLIT_FAIL;
+		}
+
+		last_ust = new_ust;
+		last_msc = new_msc;
+		last_sbc = new_sbc;
+		last_timestamp = new_timestamp;
+	}
+
+	/*
+	 * WARNING: ust inconsistent with delta msc (ust is only guaranteed to be monotnic)
+	 * ERROR: delta msc/delta wallclock time inconsistent
+	 *  - std dev too high (indicates periodicity)
+	 *  - mean isn't consistent with getMscRate (indicates correct period)
+	 */
+	if (msc_ust_duration_stats.n < 2) {
+		fprintf(stderr, "Not enough UST timing samples\n");
+	} else if (expected_msc_wallclock_duration > 0.0) {
+		double apparent_ust_rate = msc_ust_duration_stats.mean / expected_msc_wallclock_duration;
+		if (get_stddev(&msc_ust_duration_stats) / apparent_ust_rate > 100) {
+			fprintf(stderr, "UST duration per MSC is surprisingly variable (stddev %f USTs), but then it only has to be monotonic\n", get_stddev(&msc_ust_duration_stats));
+		}
+	}
+
+	if (msc_wallclock_duration_stats.n < 2) {
+		fprintf(stderr, "Not enough wallclock timing samples\n");
+	} else if (get_stddev(&msc_wallclock_duration_stats) > 1000) {
+		fprintf(stderr, "Wallclock time between MSCs has stddev > 1ms (%fus), driver is probably not syncing to vblank\n",
+			get_stddev(&msc_wallclock_duration_stats));
+		result = PIGLIT_FAIL;
+	} else if (expected_msc_wallclock_duration > 0.0) {
+		if (fabs(expected_msc_wallclock_duration - msc_wallclock_duration_stats.mean) > 50) {
+			fprintf(stderr, "Wallclock time between MSCs %fus does not match glXGetMscRateOML %f\n", msc_wallclock_duration_stats.mean, expected_msc_wallclock_duration);
+			result = PIGLIT_FAIL;
+		}
+	}
+
+	return result;
+}
+
+static unsigned int
+parse_num_arg(int argc, char **argv, int j)
+{
+	char *ptr;
+	unsigned int val;
+
+	if (j >= argc) {
+		fprintf(stderr, "%s requires an argument\n", argv[j - 1]);
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	val = strtoul(argv[j], &ptr, 0);
+	if (!val || *ptr != '\0') {
+		fprintf(stderr, "%s requires an argument\n", argv[j - 1]);
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	return val;
+}
+
+int
+main(int argc, char **argv)
+{
+	int j;
+	for (j = 1; j < argc; j++) {
+		if (!strcmp(argv[j], "-fullscreen")) {
+			fullscreen = true;
+		} else if (!strcmp(argv[j], "-waitformsc")) {
+			use_swapbuffers = false;
+		} else if (!strcmp(argv[j], "-divisor")) {
+			j++;
+			divisor = parse_num_arg(argc, argv, j);
+		} else if (!strcmp(argv[j], "-msc-delta")) {
+			j++;
+			target_msc_delta = parse_num_arg(argc, argv, j);
+		} else {
+			fprintf(stderr, "unsupported option %s\n", argv[j]);
+			piglit_report_result(PIGLIT_FAIL);
+		}
+	}
+
+	if (divisor && target_msc_delta) {
+		fprintf(stderr, "this test doesn't support using both -divisor and -msc-delta\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	if (!use_swapbuffers && !divisor && !target_msc_delta) {
+		fprintf(stderr, "when using -waitformsc, this test requires either -divisor or -msc-delta\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	piglit_automatic = true;
+	piglit_oml_sync_control_test_run(fullscreen, draw);
+
+	return 0;
+}
-- 
1.8.5.3



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