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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include <windows.h> | |
6 #include <mmsystem.h> | |
7 #include <process.h> | |
8 | |
9 #include <cmath> | |
10 #include <limits> | |
11 #include <vector> | |
12 | |
13 #include "base/threading/platform_thread.h" | |
14 #include "base/time/time.h" | |
15 #include "testing/gtest/include/gtest/gtest.h" | |
16 | |
17 using base::Time; | |
18 using base::TimeDelta; | |
19 using base::TimeTicks; | |
20 using base::TraceTicks; | |
21 | |
22 namespace { | |
23 | |
24 class MockTimeTicks : public TimeTicks { | |
25 public: | |
26 static DWORD Ticker() { | |
27 return static_cast<int>(InterlockedIncrement(&ticker_)); | |
28 } | |
29 | |
30 static void InstallTicker() { | |
31 old_tick_function_ = SetMockTickFunction(&Ticker); | |
32 ticker_ = -5; | |
33 } | |
34 | |
35 static void UninstallTicker() { | |
36 SetMockTickFunction(old_tick_function_); | |
37 } | |
38 | |
39 private: | |
40 static volatile LONG ticker_; | |
41 static TickFunctionType old_tick_function_; | |
42 }; | |
43 | |
44 volatile LONG MockTimeTicks::ticker_; | |
45 MockTimeTicks::TickFunctionType MockTimeTicks::old_tick_function_; | |
46 | |
47 HANDLE g_rollover_test_start; | |
48 | |
49 unsigned __stdcall RolloverTestThreadMain(void* param) { | |
50 int64 counter = reinterpret_cast<int64>(param); | |
51 DWORD rv = WaitForSingleObject(g_rollover_test_start, INFINITE); | |
52 EXPECT_EQ(rv, WAIT_OBJECT_0); | |
53 | |
54 TimeTicks last = TimeTicks::Now(); | |
55 for (int index = 0; index < counter; index++) { | |
56 TimeTicks now = TimeTicks::Now(); | |
57 int64 milliseconds = (now - last).InMilliseconds(); | |
58 // This is a tight loop; we could have looped faster than our | |
59 // measurements, so the time might be 0 millis. | |
60 EXPECT_GE(milliseconds, 0); | |
61 EXPECT_LT(milliseconds, 250); | |
62 last = now; | |
63 } | |
64 return 0; | |
65 } | |
66 | |
67 } // namespace | |
68 | |
69 TEST(TimeTicks, WinRollover) { | |
70 // The internal counter rolls over at ~49days. We'll use a mock | |
71 // timer to test this case. | |
72 // Basic test algorithm: | |
73 // 1) Set clock to rollover - N | |
74 // 2) Create N threads | |
75 // 3) Start the threads | |
76 // 4) Each thread loops through TimeTicks() N times | |
77 // 5) Each thread verifies integrity of result. | |
78 | |
79 const int kThreads = 8; | |
80 // Use int64 so we can cast into a void* without a compiler warning. | |
81 const int64 kChecks = 10; | |
82 | |
83 // It takes a lot of iterations to reproduce the bug! | |
84 // (See bug 1081395) | |
85 for (int loop = 0; loop < 4096; loop++) { | |
86 // Setup | |
87 MockTimeTicks::InstallTicker(); | |
88 g_rollover_test_start = CreateEvent(0, TRUE, FALSE, 0); | |
89 HANDLE threads[kThreads]; | |
90 | |
91 for (int index = 0; index < kThreads; index++) { | |
92 void* argument = reinterpret_cast<void*>(kChecks); | |
93 unsigned thread_id; | |
94 threads[index] = reinterpret_cast<HANDLE>( | |
95 _beginthreadex(NULL, 0, RolloverTestThreadMain, argument, 0, | |
96 &thread_id)); | |
97 EXPECT_NE((HANDLE)NULL, threads[index]); | |
98 } | |
99 | |
100 // Start! | |
101 SetEvent(g_rollover_test_start); | |
102 | |
103 // Wait for threads to finish | |
104 for (int index = 0; index < kThreads; index++) { | |
105 DWORD rv = WaitForSingleObject(threads[index], INFINITE); | |
106 EXPECT_EQ(rv, WAIT_OBJECT_0); | |
107 // Since using _beginthreadex() (as opposed to _beginthread), | |
108 // an explicit CloseHandle() is supposed to be called. | |
109 CloseHandle(threads[index]); | |
110 } | |
111 | |
112 CloseHandle(g_rollover_test_start); | |
113 | |
114 // Teardown | |
115 MockTimeTicks::UninstallTicker(); | |
116 } | |
117 } | |
118 | |
119 TEST(TimeTicks, SubMillisecondTimers) { | |
120 // IsHighResolution() is false on some systems. Since the product still works | |
121 // even if it's false, it makes this entire test questionable. | |
122 if (!TimeTicks::IsHighResolution()) | |
123 return; | |
124 | |
125 const int kRetries = 1000; | |
126 bool saw_submillisecond_timer = false; | |
127 | |
128 // Run kRetries attempts to see a sub-millisecond timer. | |
129 for (int index = 0; index < kRetries; index++) { | |
130 TimeTicks last_time = TimeTicks::Now(); | |
131 TimeDelta delta; | |
132 // Spin until the clock has detected a change. | |
133 do { | |
134 delta = TimeTicks::Now() - last_time; | |
135 } while (delta.InMicroseconds() == 0); | |
136 if (delta.InMicroseconds() < 1000) { | |
137 saw_submillisecond_timer = true; | |
138 break; | |
139 } | |
140 } | |
141 EXPECT_TRUE(saw_submillisecond_timer); | |
142 } | |
143 | |
144 TEST(TimeTicks, TimeGetTimeCaps) { | |
145 // Test some basic assumptions that we expect about how timeGetDevCaps works. | |
146 | |
147 TIMECAPS caps; | |
148 MMRESULT status = timeGetDevCaps(&caps, sizeof(caps)); | |
149 EXPECT_EQ(TIMERR_NOERROR, status); | |
150 if (status != TIMERR_NOERROR) { | |
151 printf("Could not get timeGetDevCaps\n"); | |
152 return; | |
153 } | |
154 | |
155 EXPECT_GE(static_cast<int>(caps.wPeriodMin), 1); | |
156 EXPECT_GT(static_cast<int>(caps.wPeriodMax), 1); | |
157 EXPECT_GE(static_cast<int>(caps.wPeriodMin), 1); | |
158 EXPECT_GT(static_cast<int>(caps.wPeriodMax), 1); | |
159 printf("timeGetTime range is %d to %dms\n", caps.wPeriodMin, | |
160 caps.wPeriodMax); | |
161 } | |
162 | |
163 TEST(TimeTicks, QueryPerformanceFrequency) { | |
164 // Test some basic assumptions that we expect about QPC. | |
165 | |
166 LARGE_INTEGER frequency; | |
167 BOOL rv = QueryPerformanceFrequency(&frequency); | |
168 EXPECT_EQ(TRUE, rv); | |
169 EXPECT_GT(frequency.QuadPart, 1000000); // Expect at least 1MHz | |
170 printf("QueryPerformanceFrequency is %5.2fMHz\n", | |
171 frequency.QuadPart / 1000000.0); | |
172 } | |
173 | |
174 TEST(TimeTicks, TimerPerformance) { | |
175 // Verify that various timer mechanisms can always complete quickly. | |
176 // Note: This is a somewhat arbitrary test. | |
177 const int kLoops = 10000; | |
178 | |
179 typedef TimeTicks (*TestFunc)(); | |
180 struct TestCase { | |
181 TestFunc func; | |
182 const char *description; | |
183 }; | |
184 // Cheating a bit here: assumes sizeof(TimeTicks) == sizeof(Time) | |
185 // in order to create a single test case list. | |
186 COMPILE_ASSERT(sizeof(TimeTicks) == sizeof(Time), | |
187 test_only_works_with_same_sizes); | |
188 TestCase cases[] = { | |
189 { reinterpret_cast<TestFunc>(&Time::Now), "Time::Now" }, | |
190 { &TimeTicks::Now, "TimeTicks::Now" }, | |
191 { reinterpret_cast<TestFunc>(&TraceTicks::Now), "TraceTicks::Now" }, | |
192 { NULL, "" } | |
193 }; | |
194 | |
195 int test_case = 0; | |
196 while (cases[test_case].func) { | |
197 TimeTicks start = TimeTicks::Now(); | |
198 for (int index = 0; index < kLoops; index++) | |
199 cases[test_case].func(); | |
200 TimeTicks stop = TimeTicks::Now(); | |
201 // Turning off the check for acceptible delays. Without this check, | |
202 // the test really doesn't do much other than measure. But the | |
203 // measurements are still useful for testing timers on various platforms. | |
204 // The reason to remove the check is because the tests run on many | |
205 // buildbots, some of which are VMs. These machines can run horribly | |
206 // slow, and there is really no value for checking against a max timer. | |
207 //const int kMaxTime = 35; // Maximum acceptible milliseconds for test. | |
208 //EXPECT_LT((stop - start).InMilliseconds(), kMaxTime); | |
209 printf("%s: %1.2fus per call\n", cases[test_case].description, | |
210 (stop - start).InMillisecondsF() * 1000 / kLoops); | |
211 test_case++; | |
212 } | |
213 } | |
214 | |
215 TEST(TimeTicks, FromQPCValue) { | |
216 if (!TimeTicks::IsHighResolution()) | |
217 return; | |
218 | |
219 LARGE_INTEGER frequency; | |
220 ASSERT_TRUE(QueryPerformanceFrequency(&frequency)); | |
221 const int64 ticks_per_second = frequency.QuadPart; | |
222 ASSERT_GT(ticks_per_second, 0); | |
223 | |
224 // Generate the tick values to convert, advancing the tick count by varying | |
225 // amounts. These values will ensure that both the fast and overflow-safe | |
226 // conversion logic in FromQPCValue() is tested, and across the entire range | |
227 // of possible QPC tick values. | |
228 std::vector<int64> test_cases; | |
229 test_cases.push_back(0); | |
230 const int kNumAdvancements = 100; | |
231 int64 ticks = 0; | |
232 int64 ticks_increment = 10; | |
233 for (int i = 0; i < kNumAdvancements; ++i) { | |
234 test_cases.push_back(ticks); | |
235 ticks += ticks_increment; | |
236 ticks_increment = ticks_increment * 6 / 5; | |
237 } | |
238 test_cases.push_back(Time::kQPCOverflowThreshold - 1); | |
239 test_cases.push_back(Time::kQPCOverflowThreshold); | |
240 test_cases.push_back(Time::kQPCOverflowThreshold + 1); | |
241 ticks = Time::kQPCOverflowThreshold + 10; | |
242 ticks_increment = 10; | |
243 for (int i = 0; i < kNumAdvancements; ++i) { | |
244 test_cases.push_back(ticks); | |
245 ticks += ticks_increment; | |
246 ticks_increment = ticks_increment * 6 / 5; | |
247 } | |
248 test_cases.push_back(std::numeric_limits<int64>::max()); | |
249 | |
250 // Test that the conversions using FromQPCValue() match those computed here | |
251 // using simple floating-point arithmetic. The floating-point math provides | |
252 // enough precision to confirm the implementation is correct to the | |
253 // microsecond for all |test_cases| (though it would be insufficient to | |
254 // confirm many "very large" tick values which are not being tested here). | |
255 for (int64 ticks : test_cases) { | |
256 const double expected_microseconds_since_origin = | |
257 (static_cast<double>(ticks) * Time::kMicrosecondsPerSecond) / | |
258 ticks_per_second; | |
259 const TimeTicks converted_value = TimeTicks::FromQPCValue(ticks); | |
260 const double converted_microseconds_since_origin = | |
261 static_cast<double>((converted_value - TimeTicks()).InMicroseconds()); | |
262 EXPECT_NEAR(expected_microseconds_since_origin, | |
263 converted_microseconds_since_origin, | |
264 1.0) | |
265 << "ticks=" << ticks << ", to be converted via logic path: " | |
266 << (ticks < Time::kQPCOverflowThreshold ? "FAST" : "SAFE"); | |
267 } | |
268 } | |
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