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// Copyright (c) 2006-2008 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 <windows.h>
#include <process.h>
#include "base/time.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace {
class MockTimeTicks : public TimeTicks {
public:
static DWORD Ticker() {
return static_cast<int>(InterlockedIncrement(&ticker_));
}
static void InstallTicker() {
old_tick_function_ = SetMockTickFunction(&Ticker);
ticker_ = -5;
}
static void UninstallTicker() {
SetMockTickFunction(old_tick_function_);
}
private:
static volatile LONG ticker_;
static TickFunctionType old_tick_function_;
};
volatile LONG MockTimeTicks::ticker_;
MockTimeTicks::TickFunctionType MockTimeTicks::old_tick_function_;
HANDLE g_rollover_test_start;
unsigned __stdcall RolloverTestThreadMain(void* param) {
int64 counter = reinterpret_cast<int64>(param);
DWORD rv = WaitForSingleObject(g_rollover_test_start, INFINITE);
EXPECT_EQ(rv, WAIT_OBJECT_0);
TimeTicks last = TimeTicks::Now();
for (int index = 0; index < counter; index++) {
TimeTicks now = TimeTicks::Now();
int64 milliseconds = (now - last).InMilliseconds();
EXPECT_GT(milliseconds, 0);
EXPECT_LT(milliseconds, 250);
last = now;
}
return 0;
}
} // namespace
TEST(TimeTicks, WinRollover) {
// The internal counter rolls over at ~49days. We'll use a mock
// timer to test this case.
// Basic test algorithm:
// 1) Set clock to rollover - N
// 2) Create N threads
// 3) Start the threads
// 4) Each thread loops through TimeTicks() N times
// 5) Each thread verifies integrity of result.
const int kThreads = 8;
// Use int64 so we can cast into a void* without a compiler warning.
const int64 kChecks = 10;
// It takes a lot of iterations to reproduce the bug!
// (See bug 1081395)
for (int loop = 0; loop < 4096; loop++) {
// Setup
MockTimeTicks::InstallTicker();
g_rollover_test_start = CreateEvent(0, TRUE, FALSE, 0);
HANDLE threads[kThreads];
for (int index = 0; index < kThreads; index++) {
void* argument = reinterpret_cast<void*>(kChecks);
unsigned thread_id;
threads[index] = reinterpret_cast<HANDLE>(
_beginthreadex(NULL, 0, RolloverTestThreadMain, argument, 0,
&thread_id));
EXPECT_NE((HANDLE)NULL, threads[index]);
}
// Start!
SetEvent(g_rollover_test_start);
// Wait for threads to finish
for (int index = 0; index < kThreads; index++) {
DWORD rv = WaitForSingleObject(threads[index], INFINITE);
EXPECT_EQ(rv, WAIT_OBJECT_0);
}
CloseHandle(g_rollover_test_start);
// Teardown
MockTimeTicks::UninstallTicker();
}
}
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