GEEKING

Microsoft.Xbox.Samples.NetworkMesh/Utils/Clock.h

@@ -0,0 +1,119 @@
+#pragma once
+
+#include <synchapi.h>
+
+class Clock
+{
+public:
+    Clock() : m_heartbeats(0), m_wakeUps(0)
+    {
+        m_timerFrequency.QuadPart = 0;
+        m_timerStart.QuadPart = 0;
+        m_countPerPeriod.QuadPart = 0;
+    }
+
+    ~Clock()
+    {
+    }
+
+    void Initialize( UINT uPeriodMS )
+    {
+        if (!QueryPerformanceFrequency(&m_timerFrequency))
+        {
+            assert(false); 
+        }
+
+        SetInterval(uPeriodMS);
+    }
+
+    void SetInterval( UINT uPeriodMS )
+    {
+        m_countPerPeriod.QuadPart = ( m_timerFrequency.QuadPart * uPeriodMS ) / c_uOneSecondInMS;
+    }
+
+    void 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: %lld", numberOfMilliSecondsSinceLast );
+            OutputDebugString( text );
+            DWORD dwSleepTime = static_cast<DWORD>(numberOfMilliSecondsSinceLast);
+            Sleep( dwSleepTime );
+        }
+    }
+
+    DWORD WaitForEventsOrHeartbeat(HANDLE hObject, HANDLE hObject2)
+    {
+        LARGE_INTEGER liExpected = GetNextHeartbeat();
+        LARGE_INTEGER liNow;
+
+        m_wakeUps = 0;
+        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);
+            m_wakeUps++;
+
+            return ::WaitForMultipleObjectsEx( 2, aObjects, false, dwSleepTime, FALSE );
+        }
+
+        // we're already late, no need to wait, but we still need to test the object
+        m_wakeUps++;
+        return ::WaitForMultipleObjectsEx( 2, aObjects, false, 0, FALSE );
+    }
+
+    UINT m_wakeUps;
+private:
+    static const UINT c_uOneSecondInMS = 1000;
+    UINT m_heartbeats;
+
+
+    LARGE_INTEGER m_timerFrequency;
+    LARGE_INTEGER m_timerStart;
+    LARGE_INTEGER m_countPerPeriod;
+
+    LARGE_INTEGER 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;
+    }
+};
+