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Diffstat (limited to 'unix/tclUnixTime.c')
| -rw-r--r-- | unix/tclUnixTime.c | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/unix/tclUnixTime.c b/unix/tclUnixTime.c new file mode 100644 index 0000000..926e8f4 --- /dev/null +++ b/unix/tclUnixTime.c @@ -0,0 +1,544 @@ +/* + * tclUnixTime.c -- + * + * Contains Unix specific versions of Tcl functions that obtain time + * values from the operating system. + * + * Copyright (c) 1995 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. + */ + +#include "tclInt.h" +#include <locale.h> +#if defined(TCL_WIDE_CLICKS) && defined(MAC_OSX_TCL) +#include <mach/mach_time.h> +#endif + +#define TM_YEAR_BASE 1900 +#define IsLeapYear(x) (((x)%4 == 0) && ((x)%100 != 0 || (x)%400 == 0)) + +/* + * TclpGetDate is coded to return a pointer to a 'struct tm'. For thread + * safety, this structure must be in thread-specific data. The 'tmKey' + * variable is the key to this buffer. + */ + +static Tcl_ThreadDataKey tmKey; +typedef struct ThreadSpecificData { + struct tm gmtime_buf; + struct tm localtime_buf; +} ThreadSpecificData; + +/* + * If we fall back on the thread-unsafe versions of gmtime and localtime, use + * this mutex to try to protect them. + */ + +TCL_DECLARE_MUTEX(tmMutex) + +static char *lastTZ = NULL; /* Holds the last setting of the TZ + * environment variable, or an empty string if + * the variable was not set. */ + +/* + * Static functions declared in this file. + */ + +static void SetTZIfNecessary(void); +static void CleanupMemory(ClientData clientData); +static void NativeScaleTime(Tcl_Time *timebuf, + ClientData clientData); +static void NativeGetTime(Tcl_Time *timebuf, + ClientData clientData); + +/* + * TIP #233 (Virtualized Time): Data for the time hooks, if any. + */ + +Tcl_GetTimeProc *tclGetTimeProcPtr = NativeGetTime; +Tcl_ScaleTimeProc *tclScaleTimeProcPtr = NativeScaleTime; +ClientData tclTimeClientData = NULL; + +/* + *---------------------------------------------------------------------- + * + * TclpGetSeconds -- + * + * This procedure returns the number of seconds from the epoch. On most + * Unix systems the epoch is Midnight Jan 1, 1970 GMT. + * + * Results: + * Number of seconds from the epoch. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +unsigned long +TclpGetSeconds(void) +{ + return time(NULL); +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetClicks -- + * + * This procedure returns a value that represents the highest resolution + * clock available on the system. There are no garantees on what the + * resolution will be. In Tcl we will call this value a "click". The + * start time is also system dependant. + * + * Results: + * Number of clicks from some start time. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +unsigned long +TclpGetClicks(void) +{ + unsigned long now; + +#ifdef NO_GETTOD + if (tclGetTimeProcPtr != NativeGetTime) { + Tcl_Time time; + + tclGetTimeProcPtr(&time, tclTimeClientData); + now = time.sec*1000000 + time.usec; + } else { + /* + * A semi-NativeGetTime, specialized to clicks. + */ + struct tms dummy; + + now = (unsigned long) times(&dummy); + } +#else + Tcl_Time time; + + tclGetTimeProcPtr(&time, tclTimeClientData); + now = time.sec*1000000 + time.usec; +#endif + + return now; +} +#ifdef TCL_WIDE_CLICKS + +/* + *---------------------------------------------------------------------- + * + * TclpGetWideClicks -- + * + * This procedure returns a WideInt value that represents the highest + * resolution clock available on the system. There are no garantees on + * what the resolution will be. In Tcl we will call this value a "click". + * The start time is also system dependant. + * + * Results: + * Number of WideInt clicks from some start time. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +Tcl_WideInt +TclpGetWideClicks(void) +{ + Tcl_WideInt now; + + if (tclGetTimeProcPtr != NativeGetTime) { + Tcl_Time time; + + tclGetTimeProcPtr(&time, tclTimeClientData); + now = (Tcl_WideInt) (time.sec*1000000 + time.usec); + } else { +#ifdef MAC_OSX_TCL + now = (Tcl_WideInt) (mach_absolute_time() & INT64_MAX); +#else +#error Wide high-resolution clicks not implemented on this platform +#endif + } + + return now; +} + +/* + *---------------------------------------------------------------------- + * + * TclpWideClicksToNanoseconds -- + * + * This procedure converts click values from the TclpGetWideClicks native + * resolution to nanosecond resolution. + * + * Results: + * Number of nanoseconds from some start time. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +double +TclpWideClicksToNanoseconds( + Tcl_WideInt clicks) +{ + double nsec; + + if (tclGetTimeProcPtr != NativeGetTime) { + nsec = clicks * 1000; + } else { +#ifdef MAC_OSX_TCL + static mach_timebase_info_data_t tb; + static uint64_t maxClicksForUInt64; + + if (!tb.denom) { + mach_timebase_info(&tb); + maxClicksForUInt64 = UINT64_MAX / tb.numer; + } + if ((uint64_t) clicks < maxClicksForUInt64) { + nsec = ((uint64_t) clicks) * tb.numer / tb.denom; + } else { + nsec = ((long double) (uint64_t) clicks) * tb.numer / tb.denom; + } +#else +#error Wide high-resolution clicks not implemented on this platform +#endif + } + + return nsec; +} +#endif /* TCL_WIDE_CLICKS */ + +/* + *---------------------------------------------------------------------- + * + * Tcl_GetTime -- + * + * Gets the current system time in seconds and microseconds since the + * beginning of the epoch: 00:00 UCT, January 1, 1970. + * + * This function is hooked, allowing users to specify their own virtual + * system time. + * + * Results: + * Returns the current time in timePtr. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_GetTime( + Tcl_Time *timePtr) /* Location to store time information. */ +{ + tclGetTimeProcPtr(timePtr, tclTimeClientData); +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetDate -- + * + * This function converts between seconds and struct tm. If useGMT is + * true, then the returned date will be in Greenwich Mean Time (GMT). + * Otherwise, it will be in the local time zone. + * + * Results: + * Returns a static tm structure. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +struct tm * +TclpGetDate( + const time_t *time, + int useGMT) +{ + if (useGMT) { + return TclpGmtime(time); + } else { + return TclpLocaltime(time); + } +} + +/* + *---------------------------------------------------------------------- + * + * TclpGmtime -- + * + * Wrapper around the 'gmtime' library function to make it thread safe. + * + * Results: + * Returns a pointer to a 'struct tm' in thread-specific data. + * + * Side effects: + * Invokes gmtime or gmtime_r as appropriate. + * + *---------------------------------------------------------------------- + */ + +struct tm * +TclpGmtime( + const time_t *timePtr) /* Pointer to the number of seconds since the + * local system's epoch */ +{ + /* + * Get a thread-local buffer to hold the returned time. + */ + + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tmKey); + +#ifdef HAVE_GMTIME_R + gmtime_r(timePtr, &tsdPtr->gmtime_buf); +#else + Tcl_MutexLock(&tmMutex); + memcpy(&tsdPtr->gmtime_buf, gmtime(timePtr), sizeof(struct tm)); + Tcl_MutexUnlock(&tmMutex); +#endif + + return &tsdPtr->gmtime_buf; +} + +/* + *---------------------------------------------------------------------- + * + * TclpLocaltime -- + * + * Wrapper around the 'localtime' library function to make it thread + * safe. + * + * Results: + * Returns a pointer to a 'struct tm' in thread-specific data. + * + * Side effects: + * Invokes localtime or localtime_r as appropriate. + * + *---------------------------------------------------------------------- + */ + +struct tm * +TclpLocaltime( + const time_t *timePtr) /* Pointer to the number of seconds since the + * local system's epoch */ +{ + /* + * Get a thread-local buffer to hold the returned time. + */ + + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tmKey); + + SetTZIfNecessary(); +#ifdef HAVE_LOCALTIME_R + localtime_r(timePtr, &tsdPtr->localtime_buf); +#else + Tcl_MutexLock(&tmMutex); + memcpy(&tsdPtr->localtime_buf, localtime(timePtr), sizeof(struct tm)); + Tcl_MutexUnlock(&tmMutex); +#endif + + return &tsdPtr->localtime_buf; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetTimeProc -- + * + * TIP #233 (Virtualized Time): Registers two handlers for the + * virtualization of Tcl's access to time information. + * + * Results: + * None. + * + * Side effects: + * Remembers the handlers, alters core behaviour. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_SetTimeProc( + Tcl_GetTimeProc *getProc, + Tcl_ScaleTimeProc *scaleProc, + ClientData clientData) +{ + tclGetTimeProcPtr = getProc; + tclScaleTimeProcPtr = scaleProc; + tclTimeClientData = clientData; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_QueryTimeProc -- + * + * TIP #233 (Virtualized Time): Query which time handlers are registered. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_QueryTimeProc( + Tcl_GetTimeProc **getProc, + Tcl_ScaleTimeProc **scaleProc, + ClientData *clientData) +{ + if (getProc) { + *getProc = tclGetTimeProcPtr; + } + if (scaleProc) { + *scaleProc = tclScaleTimeProcPtr; + } + if (clientData) { + *clientData = tclTimeClientData; + } +} + +/* + *---------------------------------------------------------------------- + * + * NativeScaleTime -- + * + * TIP #233: Scale from virtual time to the real-time. For native scaling + * the relationship is 1:1 and nothing has to be done. + * + * Results: + * Scales the time in timePtr. + * + * Side effects: + * See above. + * + *---------------------------------------------------------------------- + */ + +static void +NativeScaleTime( + Tcl_Time *timePtr, + ClientData clientData) +{ + /* Native scale is 1:1. Nothing is done */ +} + +/* + *---------------------------------------------------------------------- + * + * 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: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +NativeGetTime( + Tcl_Time *timePtr, + ClientData clientData) +{ + struct timeval tv; + + (void) gettimeofday(&tv, NULL); + timePtr->sec = tv.tv_sec; + timePtr->usec = tv.tv_usec; +} +/* + *---------------------------------------------------------------------- + * + * SetTZIfNecessary -- + * + * Determines whether a call to 'tzset' is needed prior to the next call + * to 'localtime' or examination of the 'timezone' variable. + * + * Results: + * None. + * + * Side effects: + * If 'tzset' has never been called in the current process, or if the + * value of the environment variable TZ has changed since the last call + * to 'tzset', then 'tzset' is called again. + * + *---------------------------------------------------------------------- + */ + +static void +SetTZIfNecessary(void) +{ + const char *newTZ = getenv("TZ"); + + Tcl_MutexLock(&tmMutex); + if (newTZ == NULL) { + newTZ = ""; + } + if (lastTZ == NULL || strcmp(lastTZ, newTZ)) { + tzset(); + if (lastTZ == NULL) { + Tcl_CreateExitHandler(CleanupMemory, NULL); + } else { + ckfree(lastTZ); + } + lastTZ = ckalloc(strlen(newTZ) + 1); + strcpy(lastTZ, newTZ); + } + Tcl_MutexUnlock(&tmMutex); +} + +/* + *---------------------------------------------------------------------- + * + * CleanupMemory -- + * + * Releases the private copy of the TZ environment variable upon exit + * from Tcl. + * + * Results: + * None. + * + * Side effects: + * Frees allocated memory. + * + *---------------------------------------------------------------------- + */ + +static void +CleanupMemory( + ClientData ignored) +{ + ckfree(lastTZ); +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |