GEEKING

GameChat/Utils/Clock.cpp

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+//// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
+//// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
+//// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
+//// PARTICULAR PURPOSE.
+////
+//// Copyright (c) Microsoft Corporation. All rights reserved
+#include "pch.h"
+#include "Clock.h"
+
+#if TV_API
+
+namespace Microsoft {
+namespace Xbox {
+namespace GameChat {
+
+Clock::Clock() : 
+    m_heartbeats(0)
+{
+    m_timerFrequency.QuadPart = 0;
+    m_timerStart.QuadPart = 0;
+    m_countPerPeriod.QuadPart = 0;
+}
+
+void Clock::Initialize( UINT uPeriodMS )
+{
+    if (!QueryPerformanceFrequency(&m_timerFrequency))
+    {
+        assert(false); 
+    }
+
+    SetInterval(uPeriodMS);
+}
+
+void Clock::SetInterval( UINT uPeriodMS )
+{
+    m_countPerPeriod.QuadPart = ( m_timerFrequency.QuadPart * uPeriodMS ) / c_uOneSecondInMS;
+}
+
+void Clock::SleepUntilNextHeartbeat()
+{
+    LARGE_INTEGER timeOfNextHeartbeat = GetNextHeartbeat();
+    LARGE_INTEGER timeNow;
+
+    m_heartbeats++; // so that the next one will be 20ms (or whatever) later...
+
+    if (!QueryPerformanceCounter(&timeNow))
+    {
+        assert(false); 
+    }
+
+    LONGLONG timeDelta = timeOfNextHeartbeat.QuadPart - timeNow.QuadPart;
+
+    if ( timeDelta > 0 )
+    {
+        LONGLONG numberOfMilliSecondsSinceLast = c_uOneSecondInMS * timeDelta / m_timerFrequency.QuadPart;
+        WCHAR text[200] = {0};
+        swprintf_s( text, L"I Slept: %I64d", numberOfMilliSecondsSinceLast );
+        OutputDebugString( text );
+        DWORD dwSleepTime = static_cast<DWORD>(numberOfMilliSecondsSinceLast);
+        Sleep( dwSleepTime );
+    }
+}
+
+DWORD Clock::WaitForEventsOrHeartbeat( HANDLE hObject, HANDLE hObject2 )
+{
+    LARGE_INTEGER liExpected = GetNextHeartbeat();
+    LARGE_INTEGER liNow;
+
+    m_heartbeats++; // so that the next one will be 20ms (or whatever) later...
+
+    if (!QueryPerformanceCounter(&liNow))
+    {
+        assert(false); 
+    }
+
+    LONGLONG llDiff = liExpected.QuadPart - liNow.QuadPart;
+
+    HANDLE aObjects[2];
+    aObjects[0] = hObject;
+    aObjects[1] = hObject2;
+
+    if ( llDiff > 0 )
+    {
+        DWORD dwSleepTime = static_cast<DWORD>(c_uOneSecondInMS * llDiff / m_timerFrequency.QuadPart);
+        return ::WaitForMultipleObjectsEx( 2, aObjects, false, dwSleepTime, false );
+    }
+
+    // we're already late, no need to wait, but we still need to test the object
+    return ::WaitForMultipleObjectsEx( 2, aObjects, false, 0, false );
+}
+
+LARGE_INTEGER Clock::GetNextHeartbeat()
+{
+    LARGE_INTEGER timeExpected;
+
+    // Update Start
+    if ( m_timerStart.QuadPart == 0 )
+    {
+        if (!QueryPerformanceCounter( &m_timerStart ))
+        {
+            assert(false); 
+        }
+        m_heartbeats = 1; // we are on the very first heartbeat
+    }
+
+    timeExpected.QuadPart = m_timerStart.QuadPart + (m_countPerPeriod.QuadPart * m_heartbeats);
+    return timeExpected;
+}
+
+}}}
+
+#endif