CC serialization perftests: more accurate "num runs in 2 seconds".

cc/ipc/cc_serialization_perftest.cc

 // Copyright 2013 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 <utility>
 
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "cc/ipc/cc_param_traits.h"
 #include "cc/ipc/compositor_frame.mojom.h"
@@ skipping 38 matching lines @@
     IPC::Message msg(1, 2, IPC::Message::PRIORITY_NORMAL);
     IPC::ParamTraits<CompositorFrame>::Write(&msg, frame);
     for (int i = 0; i < kNumWarmupRuns; ++i) {
       CompositorFrame compositor_frame;
       ReadMessage(&msg, &compositor_frame);
     }
 
     base::TimeTicks start = base::TimeTicks::Now();
     base::TimeTicks end =
         start + base::TimeDelta::FromMilliseconds(kTimeLimitMillis);
+    base::TimeTicks now = start;
     base::TimeDelta min_time;
     size_t count = 0;
     while (start < end) {
       for (int i = 0; i < kTimeCheckInterval; ++i) {
-        ++count;
         CompositorFrame compositor_frame;
         ReadMessage(&msg, &compositor_frame);
+        now = base::TimeTicks::Now();
+        // We don't count iterations after the end time.
+        if (now < end)
+          ++count;
       }
 
-      base::TimeTicks now = base::TimeTicks::Now();
       if (now - start < min_time || min_time.is_zero())
         min_time = now - start;
-      start = base::TimeTicks::Now();
+      start = now;
     }
 
     perf_test::PrintResult(
         "ParamTraits deserialization: min_frame_deserialization_time", "",
         test_name, min_time.InMillisecondsF() / kTimeCheckInterval * 1000, "us",
         true);
     perf_test::PrintResult("ParamTraits deserialization: num runs in 2 seconds",
                            "", test_name, count, "", true);
   }
 
   static void RunSerializationTestParamTraits(const std::string& test_name,
                                               const CompositorFrame& frame) {
     for (int i = 0; i < kNumWarmupRuns; ++i) {
       IPC::Message msg(1, 2, IPC::Message::PRIORITY_NORMAL);
       IPC::ParamTraits<CompositorFrame>::Write(&msg, frame);
     }
 
     base::TimeTicks start = base::TimeTicks::Now();
     base::TimeTicks end =
         start + base::TimeDelta::FromMilliseconds(kTimeLimitMillis);
+    base::TimeTicks now = start;
     base::TimeDelta min_time;
     size_t count = 0;
     while (start < end) {
       for (int i = 0; i < kTimeCheckInterval; ++i) {
         IPC::Message msg(1, 2, IPC::Message::PRIORITY_NORMAL);
         IPC::ParamTraits<CompositorFrame>::Write(&msg, frame);
-        ++count;
+        now = base::TimeTicks::Now();
+        // We don't count iterations after the end time.
+        if (now < end)
+          ++count;
       }
 
-      base::TimeTicks now = base::TimeTicks::Now();
       if (now - start < min_time || min_time.is_zero())
         min_time = now - start;
-      start = base::TimeTicks::Now();
+      start = now;
     }
 
     perf_test::PrintResult(
         "ParamTraits serialization: min_frame_serialization_time", "",
         test_name, min_time.InMillisecondsF() / kTimeCheckInterval * 1000, "us",
         true);
     perf_test::PrintResult("ParamTraits serialization: num runs in 2 seconds",
                            "", test_name, count, "", true);
   }
 
   static void RunDeserializationTestStructTraits(const std::string& test_name,
                                                  const CompositorFrame& frame) {
     mojo::Array<uint8_t> data = mojom::CompositorFrame::Serialize(&frame);
     DCHECK_GT(data.size(), 0u);
     for (int i = 0; i < kNumWarmupRuns; ++i) {
       CompositorFrame compositor_frame;
       mojom::CompositorFrame::Deserialize(data, &compositor_frame);
     }
 
     base::TimeTicks start = base::TimeTicks::Now();
     base::TimeTicks end =
         start + base::TimeDelta::FromMilliseconds(kTimeLimitMillis);
+    base::TimeTicks now = start;
     base::TimeDelta min_time;
     size_t count = 0;
     while (start < end) {
       for (int i = 0; i < kTimeCheckInterval; ++i) {
         CompositorFrame compositor_frame;
         mojom::CompositorFrame::Deserialize(data, &compositor_frame);
-        ++count;
+        now = base::TimeTicks::Now();
+        // We don't count iterations after the end time.
+        if (now < end)
+          ++count;
       }
 
-      base::TimeTicks now = base::TimeTicks::Now();
       if (now - start < min_time || min_time.is_zero())
         min_time = now - start;
-      start = base::TimeTicks::Now();
+      start = now;
     }
 
     perf_test::PrintResult(
         "StructTraits deserialization min_frame_deserialization_time", "",
         test_name, min_time.InMillisecondsF() / kTimeCheckInterval * 1000, "us",
         true);
     perf_test::PrintResult(
         "StructTraits deserialization: num runs in 2 seconds", "", test_name,
         count, "", true);
   }
 
   static void RunSerializationTestStructTraits(const std::string& test_name,
                                                const CompositorFrame& frame) {
     for (int i = 0; i < kNumWarmupRuns; ++i) {
       mojo::Array<uint8_t> data = mojom::CompositorFrame::Serialize(&frame);
       DCHECK_GT(data.size(), 0u);
     }
 
     base::TimeTicks start = base::TimeTicks::Now();
     base::TimeTicks end =
         start + base::TimeDelta::FromMilliseconds(kTimeLimitMillis);
+    base::TimeTicks now = start;
     base::TimeDelta min_time;
     size_t count = 0;
     while (start < end) {
       for (int i = 0; i < kTimeCheckInterval; ++i) {
         mojo::Array<uint8_t> data = mojom::CompositorFrame::Serialize(&frame);
         DCHECK_GT(data.size(), 0u);
-        ++count;
+        now = base::TimeTicks::Now();
+        // We don't count iterations after the end time.
+        if (now < end)
+          ++count;
       }
 
-      base::TimeTicks now = base::TimeTicks::Now();
       if (now - start < min_time || min_time.is_zero())
         min_time = now - start;
-      start = base::TimeTicks::Now();
+      start = now;
     }
 
     perf_test::PrintResult(
         "StructTraits serialization min_frame_serialization_time", "",
         test_name, min_time.InMillisecondsF() / kTimeCheckInterval * 1000, "us",
         true);
     perf_test::PrintResult("StructTraits serialization: num runs in 2 seconds",
                            "", test_name, count, "", true);
   }
 
@@ skipping 62 matching lines @@
                          UseSingleSharedQuadState::NO);
 }
 
 TEST_F(CCSerializationPerfTest, DelegatedFrame_ManyRenderPasses_1000_100) {
   RunCompositorFrameTest("DelegatedFrame_ManyRenderPasses_10000_100", 100, 1000,
                          UseSingleSharedQuadState::NO);
 }
 
 }  // namespace
 }  // namespace cc