diff options
Diffstat (limited to 'win')
| -rw-r--r-- | win/tclWinTime.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/win/tclWinTime.c b/win/tclWinTime.c index 70ab93d..63da982 100644 --- a/win/tclWinTime.c +++ b/win/tclWinTime.c @@ -9,7 +9,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclWinTime.c,v 1.13 2003/01/27 02:19:57 mdejong Exp $ + * RCS: @(#) $Id: tclWinTime.c,v 1.14 2003/02/14 22:16:27 kennykb Exp $ */ #include "tclWinInt.h" @@ -252,6 +252,10 @@ Tcl_GetTime(timePtr) struct timeb t; + int useFtime = 1; /* Flag == TRUE if we need to fall back + * on ftime rather than using the perf + * counter */ + /* Initialize static storage on the first trip through. */ /* @@ -360,22 +364,34 @@ Tcl_GetTime(timePtr) EnterCriticalSection( &timeInfo.cs ); QueryPerformanceCounter( &curCounter ); - curFileTime = timeInfo.lastFileTime.QuadPart - + ( ( curCounter.QuadPart - timeInfo.lastCounter.QuadPart ) - * 10000000 / timeInfo.curCounterFreq.QuadPart ); - timeInfo.lastFileTime.QuadPart = curFileTime; - timeInfo.lastCounter.QuadPart = curCounter.QuadPart; - usecSincePosixEpoch = ( curFileTime - posixEpoch.QuadPart ) / 10; - timePtr->sec = (time_t) ( usecSincePosixEpoch / 1000000 ); - timePtr->usec = (unsigned long ) ( usecSincePosixEpoch % 1000000 ); - - LeaveCriticalSection( &timeInfo.cs ); + /* + * If it appears to be more than 1.1 seconds since the last trip + * through the calibration loop, the performance counter may + * have jumped. Discard it. See MSDN Knowledge Base article + * Q274323 for a description of the hardware problem that makes + * this test necessary. + */ + if ( curCounter.QuadPart - timeInfo.lastPerfCounter + < 11 * timeInfo.estPerfCounterFreq / 10 ) { + + curFileTime = timeInfo.lastFileTime.QuadPart + + ( ( curCounter.QuadPart - timeInfo.lastCounter.QuadPart ) + * 10000000 / timeInfo.curCounterFreq.QuadPart ); + timeInfo.lastFileTime.QuadPart = curFileTime; + timeInfo.lastCounter.QuadPart = curCounter.QuadPart; + usecSincePosixEpoch = ( curFileTime - posixEpoch.QuadPart ) / 10; + timePtr->sec = (time_t) ( usecSincePosixEpoch / 1000000 ); + timePtr->usec = (unsigned long ) ( usecSincePosixEpoch % 1000000 ); + useFtime = 0; + } + LeaveCriticalSection( &timeInfo.cs ); + } - } else { + if ( useFtime ) { /* High resolution timer is not available. Just use ftime */ - + ftime(&t); timePtr->sec = t.time; timePtr->usec = t.millitm * 1000; |