gpu: Add a class MeasurementTimers that measures wall, cpu and gpu time.

gpu/perftests/measurements.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gpu/perftests/measurements.h"
+
+#include "testing/perf/perf_test.h"
+
+namespace gpu {
+
+Measurement::Measurement() : name(), wall_time(), cpu_time(), gpu_time() {
+}
+Measurement::Measurement(const Measurement& m)
+    : name(m.name),
+      wall_time(m.wall_time),
+      cpu_time(m.cpu_time),
+      gpu_time(m.gpu_time) {
+}
+Measurement::Measurement(const std::string& name,
+                         const base::TimeDelta wall_time,
+                         const base::TimeDelta cpu_time,
+                         const base::TimeDelta gpu_time)
+    : name(name), wall_time(wall_time), cpu_time(cpu_time), gpu_time(gpu_time) {
+}
+
+void Measurement::PrintResult() const {
+  perf_test::PrintResult(name, "_wall", "", wall_time.InMillisecondsF(), "ms",
+                         true);
+  perf_test::PrintResult(name, "_cpu", "", cpu_time.InMillisecondsF(), "ms",
+                         true);
+  perf_test::PrintResult(name, "_gpu", "", gpu_time.InMillisecondsF(), "ms",
+                         true);
+}
+
+Measurement& Measurement::Increment(const Measurement& m) {
+  wall_time += m.wall_time;
+  cpu_time += m.cpu_time;
+  gpu_time += m.gpu_time;
+  return *this;
+}
+
+Measurement Measurement::Divide(int a) const {
+  return Measurement(name, wall_time / a, cpu_time / a, gpu_time / a);
+}
+
+Measurement::~Measurement() {
+}
+
+MeasurementTimers::MeasurementTimers()
+    : wall_timer_(), cpu_time_begin_(), cpu_time_() {
+  if (base::TimeTicks::IsThreadNowSupported()) {
+    cpu_time_begin_ = base::TimeTicks::ThreadNow();
+  }
+
+  glGenQueriesARB(2, gl_queries_);
+
+  glQueryCounter(gl_queries_[0], GL_TIMESTAMP);

[piman, 2015/01/30 21:12:04]

This only works with GL_ARB_timer_query, which is not available everywhere.
There is also GL_EXT_disjoint_timer_query which has some subtle differences. Or
it's possible that the platform has neither of those, and we can't directly get
GPU timestamps.

See the code in GPUTracer (in gpu/command_buffer/service/gpu_tracer.cc) which
attempts to deal with the differences.

It may be good to extract/reuse that part of the code?

[Daniele Castagna, 2015/02/03 04:12:59]

Makes sense. I already reached out to dyen@ and vmiura@. I'm trying to extract
the GPU timing related code from gpu_tracer. I'll update here as soon as I have
a cl for that.

[Daniele Castagna, 2015/02/06 22:52:00]

Still working with dyen@ on this: crrev.com/904743002.

[Daniele Castagna, 2015/02/13 21:17:42]

Done.

+  CHECK(glIsQueryARB(gl_queries_[0]));

[piman, 2015/01/30 21:12:04]

nit: DCHECK instead of CHECK (here and other places).

[Daniele Castagna, 2015/02/03 04:12:59]

Done.

+}
+
+void MeasurementTimers::Record() {
+  wall_time_ = wall_timer_.Elapsed();
+  if (base::TimeTicks::IsThreadNowSupported()) {
+    cpu_time_ = base::TimeTicks::ThreadNow() - cpu_time_begin_;
+  } else {
+    static bool logged_once = false;
+    LOG_IF(WARNING, !logged_once) << "ThreadNow not supported. :(";
+    logged_once = true;
+  }
+
+  glQueryCounter(gl_queries_[1], GL_TIMESTAMP);
+  CHECK(glIsQueryARB(gl_queries_[1]));
+}
+
+Measurement MeasurementTimers::GetAsMeasurement(const std::string& name) {
+  CHECK_NE(base::TimeDelta(), wall_time_);  // At least wall_time_ has been set.
+  GLint done = 0;
+  glGetQueryObjectivARB(gl_queries_[1], GL_QUERY_RESULT_AVAILABLE, &done);
+  CHECK_GT(done, 0);
+
+  GLuint64 gl_start = 0;
+  GLuint64 gl_end = 0;
+  glGetQueryObjectui64v(gl_queries_[0], GL_QUERY_RESULT, &gl_start);
+  glGetQueryObjectui64v(gl_queries_[1], GL_QUERY_RESULT, &gl_end);
+
+  int64 gpu_time = (gl_end - gl_start) / base::Time::kNanosecondsPerMicrosecond;
+  return Measurement(name, wall_time_, cpu_time_,
+                     base::TimeDelta::FromMicroseconds(gpu_time));
+}
+
+MeasurementTimers::~MeasurementTimers() {
+  glDeleteQueriesARB(2, gl_queries_);
+}
+
+}  // namespace gpu