Add synthetic delay testing framework

base/debug/trace_event_synthetic_delay_unittest.cc

+// Copyright (c) 2014 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 "base/debug/trace_event_synthetic_delay.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace debug {
+namespace {
+
+const int kTargetDurationMs = 100;
+// Allow some leeway in timings to make it possible to run these tests with a
+// wall clock time source too.
+const int kShortDurationMs = 10;
+
+}  // namespace
+
+class TraceEventSyntheticDelayTest : public testing::Test,
+                                     public TraceEventSyntheticDelayClock {
+ public:
+  TraceEventSyntheticDelayTest() {}
+
+  // TraceEventSyntheticDelayClock implementation.
+  virtual base::TimeTicks Now() OVERRIDE {
+    AdvanceTime(base::TimeDelta::FromMilliseconds(kShortDurationMs / 10));
+    return now_;
+  }
+
+  TraceEventSyntheticDelay* ConfigureDelay(const char* name) {
+    TraceEventSyntheticDelay* delay = TraceEventSyntheticDelay::Lookup(name);
+    delay->SetClock(this);
+    delay->SetTargetDuration(
+        base::TimeDelta::FromMilliseconds(kTargetDurationMs));
+    return delay;
+  }
+
+  void AdvanceTime(base::TimeDelta delta) { now_ += delta; }
+
+  int TestFunction() {
+    base::TimeTicks start = Now();
+    { TRACE_EVENT_SYNTHETIC_DELAY("test.Delay"); }
+    return (Now() - start).InMilliseconds();
+  }
+
+  int AsyncTestFunctionActivate() {
+    base::TimeTicks start = Now();
+    { TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE("test.AsyncDelay"); }
+    return (Now() - start).InMilliseconds();
+  }
+
+  int AsyncTestFunctionApply() {
+    base::TimeTicks start = Now();
+    { TRACE_EVENT_SYNTHETIC_DELAY_APPLY("test.AsyncDelay"); }
+    return (Now() - start).InMilliseconds();
+  }
+
+ private:
+  base::TimeTicks now_;
+
+  DISALLOW_COPY_AND_ASSIGN(TraceEventSyntheticDelayTest);
+};
+
+TEST_F(TraceEventSyntheticDelayTest, StaticDelay) {
+  TraceEventSyntheticDelay* delay = ConfigureDelay("test.Delay");
+  delay->SetMode(TraceEventSyntheticDelay::STATIC);
+  EXPECT_GE(TestFunction(), kTargetDurationMs);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, OneShotDelay) {
+  TraceEventSyntheticDelay* delay = ConfigureDelay("test.Delay");
+  delay->SetMode(TraceEventSyntheticDelay::ONE_SHOT);
+  EXPECT_GE(TestFunction(), kTargetDurationMs);
+  EXPECT_LT(TestFunction(), kShortDurationMs);
+
+  delay->SetTargetDuration(
+      base::TimeDelta::FromMilliseconds(kTargetDurationMs));
+  EXPECT_GE(TestFunction(), kTargetDurationMs);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, AlternatingDelay) {
+  TraceEventSyntheticDelay* delay = ConfigureDelay("test.Delay");
+  delay->SetMode(TraceEventSyntheticDelay::ALTERNATING);
+  EXPECT_GE(TestFunction(), kTargetDurationMs);
+  EXPECT_LT(TestFunction(), kShortDurationMs);
+  EXPECT_GE(TestFunction(), kTargetDurationMs);
+  EXPECT_LT(TestFunction(), kShortDurationMs);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, AsyncDelay) {
+  ConfigureDelay("test.AsyncDelay");
+  EXPECT_LT(AsyncTestFunctionActivate(), kShortDurationMs);
+  EXPECT_GE(AsyncTestFunctionApply(), kTargetDurationMs / 2);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, AsyncDelayExceeded) {
+  ConfigureDelay("test.AsyncDelay");
+  EXPECT_LT(AsyncTestFunctionActivate(), kShortDurationMs);
+  AdvanceTime(base::TimeDelta::FromMilliseconds(kTargetDurationMs));
+  EXPECT_LT(AsyncTestFunctionApply(), kShortDurationMs);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, AsyncDelayNoActivation) {
+  ConfigureDelay("test.AsyncDelay");
+  EXPECT_LT(AsyncTestFunctionApply(), kShortDurationMs);
+}
+
+TEST_F(TraceEventSyntheticDelayTest, AsyncDelayMultipleActivations) {
+  ConfigureDelay("test.AsyncDelay");
+  EXPECT_LT(AsyncTestFunctionActivate(), kShortDurationMs);
+  AdvanceTime(base::TimeDelta::FromMilliseconds(kTargetDurationMs));
+  EXPECT_LT(AsyncTestFunctionActivate(), kShortDurationMs);
+  EXPECT_LT(AsyncTestFunctionApply(), kShortDurationMs);
+}
+
+}  // namespace debug
+}  // namespace base