diff options
Diffstat (limited to 'win/tclWinTime.c')
-rw-r--r-- | win/tclWinTime.c | 271 |
1 files changed, 232 insertions, 39 deletions
diff --git a/win/tclWinTime.c b/win/tclWinTime.c index 2ea9e86..e1aff48 100644 --- a/win/tclWinTime.c +++ b/win/tclWinTime.c @@ -110,6 +110,17 @@ static TimeInfo timeInfo = { }; /* + * Scale to convert wide click values from the TclpGetWideClicks native + * resolution to microsecond resolution and back. + */ +static struct { + int initialized; /* 1 if initialized, 0 otherwise */ + int perfCounter; /* 1 if performance counter usable for wide clicks */ + double microsecsScale; /* Denominator scale between clock / microsecs */ +} wideClick = {0, 0.0}; + + +/* * Declarations for functions defined later in this file. */ @@ -123,6 +134,7 @@ static Tcl_WideInt AccumulateSample(Tcl_WideInt perfCounter, Tcl_WideUInt fileTime); static void NativeScaleTime(Tcl_Time* timebuf, ClientData clientData); +static Tcl_WideInt NativeGetMicroseconds(void); static void NativeGetTime(Tcl_Time* timebuf, ClientData clientData); @@ -154,10 +166,19 @@ ClientData tclTimeClientData = NULL; unsigned long TclpGetSeconds(void) { - Tcl_Time t; + Tcl_WideInt usecSincePosixEpoch; - tclGetTimeProcPtr(&t, tclTimeClientData); /* Tcl_GetTime inlined. */ - return t.sec; + /* Try to use high resolution timer */ + if ( tclGetTimeProcPtr == NativeGetTime + && (usecSincePosixEpoch = NativeGetMicroseconds()) + ) { + return usecSincePosixEpoch / 1000000; + } else { + Tcl_Time t; + + tclGetTimeProcPtr(&t, tclTimeClientData); /* Tcl_GetTime inlined. */ + return t.sec; + } } /* @@ -182,19 +203,147 @@ TclpGetSeconds(void) unsigned long TclpGetClicks(void) { - /* - * Use the Tcl_GetTime abstraction to get the time in microseconds, as - * nearly as we can, and return it. - */ + Tcl_WideInt usecSincePosixEpoch; + + /* Try to use high resolution timer */ + if ( tclGetTimeProcPtr == NativeGetTime + && (usecSincePosixEpoch = NativeGetMicroseconds()) + ) { + return (unsigned long)usecSincePosixEpoch; + } else { + /* + * Use the Tcl_GetTime abstraction to get the time in microseconds, as + * nearly as we can, and return it. + */ + + Tcl_Time now; /* Current Tcl time */ + + tclGetTimeProcPtr(&now, tclTimeClientData); /* Tcl_GetTime inlined */ + return (unsigned long)(now.sec * 1000000) + now.usec; + } +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetWideClicks -- + * + * This procedure returns a WideInt value that represents the highest + * resolution clock in microseconds available on the system. + * + * Results: + * Number of microseconds (from some start time). + * + * Side effects: + * This should be used for time-delta resp. for measurement purposes + * only, because on some platforms can return microseconds from some + * start time (not from the epoch). + * + *---------------------------------------------------------------------- + */ + +Tcl_WideInt +TclpGetWideClicks(void) +{ + LARGE_INTEGER curCounter; + + if (!wideClick.initialized) { + LARGE_INTEGER perfCounterFreq; + + /* + * The frequency of the performance counter is fixed at system boot and + * is consistent across all processors. Therefore, the frequency need + * only be queried upon application initialization. + */ + if (QueryPerformanceFrequency(&perfCounterFreq)) { + wideClick.perfCounter = 1; + wideClick.microsecsScale = 1000000.0 / perfCounterFreq.QuadPart; + } else { + /* fallback using microseconds */ + wideClick.perfCounter = 0; + wideClick.microsecsScale = 1; + } + + wideClick.initialized = 1; + } + if (wideClick.perfCounter) { + if (QueryPerformanceCounter(&curCounter)) { + return (Tcl_WideInt)curCounter.QuadPart; + } + /* fallback using microseconds */ + wideClick.perfCounter = 0; + wideClick.microsecsScale = 1; + return TclpGetMicroseconds(); + } else { + return TclpGetMicroseconds(); + } +} + +/* + *---------------------------------------------------------------------- + * + * TclpWideClickInMicrosec -- + * + * This procedure return scale to convert wide click values from the + * TclpGetWideClicks native resolution to microsecond resolution + * and back. + * + * Results: + * 1 click in microseconds as double. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +double +TclpWideClickInMicrosec(void) +{ + if (!wideClick.initialized) { + (void)TclpGetWideClicks(); /* initialize */ + } + return wideClick.microsecsScale; +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetMicroseconds -- + * + * This procedure returns a WideInt value that represents the highest + * resolution clock in microseconds available on the system. + * + * Results: + * Number of microseconds (from the epoch). + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ - Tcl_Time now; /* Current Tcl time */ - unsigned long retval; /* Value to return */ +Tcl_WideInt +TclpGetMicroseconds(void) +{ + Tcl_WideInt usecSincePosixEpoch; - tclGetTimeProcPtr(&now, tclTimeClientData); /* Tcl_GetTime inlined */ + /* Try to use high resolution timer */ + if ( tclGetTimeProcPtr == NativeGetTime + && (usecSincePosixEpoch = NativeGetMicroseconds()) + ) { + return usecSincePosixEpoch; + } else { + /* + * Use the Tcl_GetTime abstraction to get the time in microseconds, as + * nearly as we can, and return it. + */ - retval = (now.sec * 1000000) + now.usec; - return retval; + Tcl_Time now; + tclGetTimeProcPtr(&now, tclTimeClientData); /* Tcl_GetTime inlined */ + return (((Tcl_WideInt)now.sec) * 1000000) + now.usec; + } } /* @@ -223,7 +372,17 @@ void Tcl_GetTime( Tcl_Time *timePtr) /* Location to store time information. */ { - tclGetTimeProcPtr(timePtr, tclTimeClientData); + Tcl_WideInt usecSincePosixEpoch; + + /* Try to use high resolution timer */ + if ( tclGetTimeProcPtr == NativeGetTime + && (usecSincePosixEpoch = NativeGetMicroseconds()) + ) { + timePtr->sec = (long) (usecSincePosixEpoch / 1000000); + timePtr->usec = (unsigned long) (usecSincePosixEpoch % 1000000); + } else { + tclGetTimeProcPtr(timePtr, tclTimeClientData); + } } /* @@ -256,13 +415,14 @@ NativeScaleTime( /* *---------------------------------------------------------------------- * - * NativeGetTime -- + * NativeGetMicroseconds -- * - * TIP #233: Gets the current system time in seconds and microseconds - * since the beginning of the epoch: 00:00 UCT, January 1, 1970. + * Gets the current system time in microseconds since the beginning + * of the epoch: 00:00 UCT, January 1, 1970. * * Results: - * Returns the current time in timePtr. + * Returns the wide integer with number of microseconds from the epoch, or + * 0 if high resolution timer is not available. * * Side effects: * On the first call, initializes a set of static variables to keep track @@ -275,13 +435,12 @@ NativeScaleTime( *---------------------------------------------------------------------- */ -static void -NativeGetTime( - Tcl_Time *timePtr, - ClientData clientData) +static Tcl_WideInt +NativeGetMicroseconds(void) { - struct _timeb t; - + static LARGE_INTEGER posixEpoch; + /* Posix epoch expressed as 100-ns ticks since + * the windows epoch. */ /* * Initialize static storage on the first trip through. * @@ -292,6 +451,10 @@ NativeGetTime( if (!timeInfo.initialized) { TclpInitLock(); if (!timeInfo.initialized) { + + posixEpoch.LowPart = 0xD53E8000; + posixEpoch.HighPart = 0x019DB1DE; + timeInfo.perfCounterAvailable = QueryPerformanceFrequency(&timeInfo.nominalFreq); @@ -404,15 +567,9 @@ NativeGetTime( /* Current performance counter. */ Tcl_WideInt curFileTime;/* Current estimated time, expressed as 100-ns * ticks since the Windows epoch. */ - static LARGE_INTEGER posixEpoch; - /* Posix epoch expressed as 100-ns ticks since - * the windows epoch. */ Tcl_WideInt usecSincePosixEpoch; /* Current microseconds since Posix epoch. */ - posixEpoch.LowPart = 0xD53E8000; - posixEpoch.HighPart = 0x019DB1DE; - QueryPerformanceCounter(&curCounter); /* @@ -432,9 +589,7 @@ NativeGetTime( if (curCounter.QuadPart <= perfCounterLastCall.QuadPart) { usecSincePosixEpoch = (fileTimeLastCall.QuadPart - posixEpoch.QuadPart) / 10; - timePtr->sec = (long) (usecSincePosixEpoch / 1000000); - timePtr->usec = (unsigned long) (usecSincePosixEpoch % 1000000); - return; + return usecSincePosixEpoch; } /* @@ -455,19 +610,57 @@ NativeGetTime( * 10000000 / curCounterFreq.QuadPart); usecSincePosixEpoch = (curFileTime - posixEpoch.QuadPart) / 10; - timePtr->sec = (long) (usecSincePosixEpoch / 1000000); - timePtr->usec = (unsigned long) (usecSincePosixEpoch % 1000000); - return; + return usecSincePosixEpoch; } } /* - * High resolution timer is not available. Just use ftime. + * High resolution timer is not available. */ + return 0; +} + +/* + *---------------------------------------------------------------------- + * + * NativeGetTime -- + * + * TIP #233: Gets the current system time in seconds and microseconds + * since the beginning of the epoch: 00:00 UCT, January 1, 1970. + * + * Results: + * Returns the current time in timePtr. + * + * Side effects: + * See NativeGetMicroseconds for more information. + * + *---------------------------------------------------------------------- + */ + +static void +NativeGetTime( + Tcl_Time *timePtr, + ClientData clientData) +{ + Tcl_WideInt usecSincePosixEpoch; - _ftime(&t); - timePtr->sec = (long)t.time; - timePtr->usec = t.millitm * 1000; + /* + * Try to use high resolution timer. + */ + if ( (usecSincePosixEpoch = NativeGetMicroseconds()) ) { + timePtr->sec = (long) (usecSincePosixEpoch / 1000000); + timePtr->usec = (unsigned long) (usecSincePosixEpoch % 1000000); + } else { + /* + * High resolution timer is not available. Just use ftime. + */ + + struct _timeb t; + + _ftime(&t); + timePtr->sec = (long)t.time; + timePtr->usec = t.millitm * 1000; + } } /* |