1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/boardsupport/emulator/emulatorbsp/specific/timer.cpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,176 @@
1.4 +// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +// wins\specific\timer.cpp
1.18 +//
1.19 +//
1.20 +
1.21 +#include "variant.h"
1.22 +
1.23 +#define KWinsTimerPanicCategory "WinsTimer"
1.24 +
1.25 +enum TWinsTimerPanic
1.26 + {
1.27 + EReleaseSemaphoreError = 1,
1.28 + ETimeSetEventError = 2
1.29 + };
1.30 +
1.31 +void PanicFromWinsTimer(TWinsTimerPanic aReason)
1.32 + {
1.33 + Kern::Fault(KWinsTimerPanicCategory, aReason);
1.34 + }
1.35 +
1.36 +
1.37 +
1.38 +inline Int64 FileTime2Milliseconds(const FILETIME& aFileTime)
1.39 + {return ((Int64(aFileTime.dwHighDateTime)<<32) + aFileTime.dwLowDateTime)/10000;}
1.40 +
1.41 +
1.42 +void CALLBACK WinsTimer::Tick(UINT, UINT, DWORD aPtr, DWORD, DWORD)
1.43 + {
1.44 +
1.45 + WinsTimer& timer=*(WinsTimer*)aPtr;
1.46 + if (!ReleaseSemaphore(timer.iSemaphore,1,NULL))
1.47 + {
1.48 + __ASSERT_ALWAYS((GetLastError() == ERROR_TOO_MANY_POSTS), PanicFromWinsTimer(EReleaseSemaphoreError));
1.49 + timeKillEvent(timer.iTimer);
1.50 + // If WinsTimer::EventThread() has run since the above call to
1.51 + // ReleaseSemaphore() (this has been observed to happen while
1.52 + // within the call to timeKillEvent()) then the semaphore may be
1.53 + // signallable again. If it is, restart the timer otherwise wait
1.54 + // for the event thread to restart it.
1.55 + if (ReleaseSemaphore(timer.iSemaphore,1,NULL))
1.56 + timer.Enable();
1.57 + else
1.58 + timer.iSuspend = timer.iMaxLagTicks;
1.59 + }
1.60 + }
1.61 +
1.62 +DWORD WINAPI WinsTimer::Thread(LPVOID aPtr)
1.63 + {
1.64 + static_cast<WinsTimer*>(aPtr)->EventThread(*(NTimerQ*)NTimerQ::TimerAddress());
1.65 + return 0;
1.66 + }
1.67 +
1.68 +void WinsTimer::EventThread(NTimerQ& aTimerQ)
1.69 + {
1.70 + for (;;)
1.71 + {
1.72 + WaitForSingleObject(iSemaphore,INFINITE);
1.73 + if (iSuspend > 0)
1.74 + {
1.75 + // Emulator interrupted/suspended for too long, MM-callback has been suspended
1.76 + //
1.77 + // Rather than try and catch up now, just discard the lost ticks - this improves
1.78 + // system behaviour particularly when debugging at the expense of losing sync
1.79 + // between the Windows clock and the emulator RTC.
1.80 + //
1.81 + while (--iSuspend > 0)
1.82 + WaitForSingleObject(iSemaphore, 0); // absorb all signals
1.83 + //
1.84 + // un-nobble once we are debugging
1.85 + if (iNobbleNanos && IsDebuggerPresent())
1.86 + iNobbleNanos = 0;
1.87 + //
1.88 + // now restart the timer callbacks
1.89 + Enable();
1.90 + //
1.91 + // don't deliver a tick until next callback
1.92 + continue;
1.93 + }
1.94 + if (iNobbleNanos && iIdleThread != NKern::CurrentThread())
1.95 + Kern::NanoWait(iNobbleNanos);
1.96 + StartOfInterrupt();
1.97 + iTime += iPeriod;
1.98 + if (!iStandby)
1.99 + aTimerQ.Tick();
1.100 + EndOfInterrupt();
1.101 + }
1.102 + }
1.103 +
1.104 +
1.105 +WinsTimer::WinsTimer()
1.106 + :iPeriod(0),iNobbleNanos(0),iMaxLagTicks(0),iSemaphore(NULL),iSuspend(0),iTime(0),iIdleThread(0)
1.107 + {}
1.108 +
1.109 +void WinsTimer::Init(TUint aPeriod)
1.110 + {
1.111 + // calculate the y2k offset in seconds from Win32 'zero' FILETIME
1.112 + // This initially synchronizes EPOC time with Windows time
1.113 + const SYSTEMTIME KSystemTimeY2K = {2000,1,0,1,0,0,0,0};
1.114 + FILETIME y2k, now;
1.115 + SystemTimeToFileTime(&KSystemTimeY2K,&y2k);
1.116 + GetSystemTimeAsFileTime(&now);
1.117 + iTime = FileTime2Milliseconds(now) - FileTime2Milliseconds(y2k);
1.118 +
1.119 + TIMECAPS caps;
1.120 + timeGetDevCaps(&caps,sizeof(caps));
1.121 +
1.122 + iPeriod = min(caps.wPeriodMax, max(caps.wPeriodMin, aPeriod));
1.123 + TUint resolution = max(caps.wPeriodMin, iPeriod/2);
1.124 + iMaxLagTicks = EMaxLag / iPeriod;
1.125 +
1.126 + // limit 'catch-up' for when Win32 gets too busy for us to fire timer events
1.127 + // making this too large causes delays when resuming from debug
1.128 + iSemaphore = CreateSemaphoreA(NULL, 0, iMaxLagTicks, NULL);
1.129 +
1.130 + timeBeginPeriod(resolution);
1.131 +
1.132 + CreateWin32Thread(EThreadEvent, &WinsTimer::Thread, this, ETrue);
1.133 + }
1.134 +
1.135 +void WinsTimer::Enable()
1.136 + {
1.137 + iTimer = timeSetEvent(iPeriod,0,&WinsTimer::Tick,DWORD(this),TIME_PERIODIC);
1.138 + __ASSERT_ALWAYS(iTimer != NULL, PanicFromWinsTimer(ETimeSetEventError));
1.139 + }
1.140 +
1.141 +TInt WinsTimer::SystemTime() const
1.142 +//
1.143 +// Return the time in seconds since y2k
1.144 +//
1.145 + {
1.146 + TInt irq = NKern::DisableAllInterrupts();
1.147 + Int64 time = iTime;
1.148 + NKern::RestoreInterrupts(irq);
1.149 + if (time < 0)
1.150 + time -= 999; // we want rounding to -infinity for the division
1.151 + return TInt(time/1000);
1.152 + }
1.153 +
1.154 +void WinsTimer::SetSystemTime(TInt aTime)
1.155 +//
1.156 +// Set the time in seconds since y2k
1.157 +//
1.158 + {
1.159 + Int64 time=aTime;
1.160 + time*=1000;
1.161 + TInt irq = NKern::DisableAllInterrupts();
1.162 + iTime = time;
1.163 + NKern::RestoreInterrupts(irq);
1.164 + }
1.165 +
1.166 +void WinsTimer::Standby()
1.167 + {
1.168 + iStandby = ETrue;
1.169 + }
1.170 +
1.171 +void WinsTimer::Wakeup()
1.172 + {
1.173 + iStandby = EFalse;
1.174 + // Busy wait for the next timer interrupt
1.175 + volatile Int64* t = &iTime;
1.176 + Int64 time = *t;
1.177 + while (time == *t)
1.178 + {}
1.179 + }
1.180 \ No newline at end of file