diff options
Diffstat (limited to 'unix/tclUnixTime.c')
| -rw-r--r-- | unix/tclUnixTime.c | 251 |
1 files changed, 162 insertions, 89 deletions
diff --git a/unix/tclUnixTime.c b/unix/tclUnixTime.c index 37c16bc..6def210 100644 --- a/unix/tclUnixTime.c +++ b/unix/tclUnixTime.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: tclUnixTime.c,v 1.20 2004/04/06 22:25:57 dgp Exp $ + * RCS: @(#) $Id: tclUnixTime.c,v 1.21 2004/05/14 21:43:29 kennykb Exp $ */ #include "tclInt.h" @@ -24,22 +24,27 @@ */ 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. */ -#if !defined(HAVE_GMTIME_R) || !defined(HAVE_LOCALTIME_R) TCL_DECLARE_MUTEX(tmMutex) -#endif -/* - * Forward declarations for procedures defined later in this file. - */ +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 struct tm *ThreadSafeGMTime _ANSI_ARGS_(( CONST time_t* )); -static struct tm *ThreadSafeLocalTime _ANSI_ARGS_(( CONST time_t* )); +static void SetTZIfNecessary _ANSI_ARGS_((void)); +static void CleanupMemory _ANSI_ARGS_((ClientData)); /* *----------------------------------------------------------------------------- @@ -128,18 +133,22 @@ TclpGetTimeZone (currentTime) unsigned long currentTime; { /* - * Determine how a timezone is obtained from "struct tm". If there is no - * time zone in this struct (very lame) then use the timezone variable. - * This is done in a way to make the timezone variable the method of last - * resort, as some systems have it in addition to a field in "struct tm". - * The gettimeofday system call can also be used to determine the time - * zone. + * We prefer first to use the time zone in "struct tm" if the + * structure contains such a member. Following that, we try + * to locate the external 'timezone' variable and use its value. + * If both of those methods fail, we attempt to convert a known + * time to local time and use the difference from UTC as the local + * time zone. In all cases, we need to undo any Daylight Saving Time + * adjustment. */ #if defined(HAVE_TM_TZADJ) # define TCL_GOT_TIMEZONE + + /* Struct tm contains tm_tzadj - that value may be used. */ + time_t curTime = (time_t) currentTime; - struct tm *timeDataPtr = ThreadSafeLocalTime(&curTime); + struct tm *timeDataPtr = TclpLocaltime(&curTime); int timeZone; timeZone = timeDataPtr->tm_tzadj / 60; @@ -148,12 +157,16 @@ TclpGetTimeZone (currentTime) } return timeZone; + #endif #if defined(HAVE_TM_GMTOFF) && !defined (TCL_GOT_TIMEZONE) # define TCL_GOT_TIMEZONE + + /* Struct tm contains tm_gmtoff - that value may be used. */ + time_t curTime = (time_t) currentTime; - struct tm *timeDataPtr = ThreadSafeLocalTime(&curTime); + struct tm *timeDataPtr = TclpLocaltime(&curTime); int timeZone; timeZone = -(timeDataPtr->tm_gmtoff / 60); @@ -162,46 +175,17 @@ TclpGetTimeZone (currentTime) } return timeZone; -#endif - -#if defined(USE_DELTA_FOR_TZ) -#define TCL_GOT_TIMEZONE 1 - /* - * This hack replaces using global var timezone or gettimeofday - * in situations where they are buggy such as on AIX when libbsd.a - * is linked in. - */ - int timeZone; - time_t tt; - struct tm *stm; - tt = 849268800L; /* 1996-11-29 12:00:00 GMT */ - stm = ThreadSafeLocalTime(&tt); /* eg 1996-11-29 6:00:00 CST6CDT */ - /* The calculation below assumes a max of +12 or -12 hours from GMT */ - timeZone = (12 - stm->tm_hour)*60 + (0 - stm->tm_min); - return timeZone; /* eg +360 for CST6CDT */ #endif - /* - * Must prefer timezone variable over gettimeofday, as gettimeofday does - * not return timezone information on many systems that have moved this - * information outside of the kernel. - */ - -#if defined(HAVE_TIMEZONE_VAR) && !defined (TCL_GOT_TIMEZONE) +#if defined(HAVE_TIMEZONE_VAR) && !defined(TCL_GOT_TIMEZONE) && !defined(USE_DELTA_FOR_TZ) # define TCL_GOT_TIMEZONE - static int setTZ = 0; -#ifdef TCL_THREADS - static Tcl_Mutex tzMutex; -#endif - int timeZone; - Tcl_MutexLock(&tzMutex); - if (!setTZ) { - tzset(); - setTZ = 1; - } - Tcl_MutexUnlock(&tzMutex); + int timeZone; + + /* The 'timezone' external var is present and may be used. */ + + SetTZIfNecessary(); /* * Note: this is not a typo in "timezone" below! See tzset @@ -209,30 +193,36 @@ TclpGetTimeZone (currentTime) */ timeZone = timezone / 60; - return timeZone; + #endif -#if !defined(NO_GETTOD) && !defined (TCL_GOT_TIMEZONE) -# define TCL_GOT_TIMEZONE - struct timeval tv; - struct timezone tz; - int timeZone; +#if !defined(TCL_GOT_TIMEZONE) +#define TCL_GOT_TIMEZONE 1 + /* + * Fallback - determine time zone with a known reference time. + */ - gettimeofday(&tv, &tz); - timeZone = tz.tz_minuteswest; - if (tz.tz_dsttime) { - timeZone += 60; + int timeZone; + time_t tt; + struct tm *stm; + tt = 849268800L; /* 1996-11-29 12:00:00 GMT */ + stm = TclpLocaltime(&tt); /* eg 1996-11-29 6:00:00 CST6CDT */ + /* The calculation below assumes a max of +12 or -12 hours from GMT */ + timeZone = (12 - stm->tm_hour)*60 + (0 - stm->tm_min); + if ( stm -> tm_isdst ) { + timeZone += 60; } - - return timeZone; + return timeZone; /* eg +360 for CST6CDT */ #endif #ifndef TCL_GOT_TIMEZONE /* * Cause compile error, we don't know how to get timezone. */ - error: autoconf did not figure out how to determine the timezone. + +#error autoconf did not figure out how to determine the timezone. + #endif } @@ -290,9 +280,9 @@ TclpGetDate(time, useGMT) int useGMT; { if (useGMT) { - return ThreadSafeGMTime(time); + return TclpGmtime(time); } else { - return ThreadSafeLocalTime(time); + return TclpLocaltime(time); } } @@ -354,7 +344,7 @@ TclpStrftime(s, maxsize, format, t, useGMT) /* *---------------------------------------------------------------------- * - * ThreadSafeGMTime -- + * TclpGmtime -- * * Wrapper around the 'gmtime' library function to make it thread * safe. @@ -368,33 +358,42 @@ TclpStrftime(s, maxsize, format, t, useGMT) *---------------------------------------------------------------------- */ -static struct tm * -ThreadSafeGMTime(timePtr) +struct tm * +TclpGmtime( timePtr ) CONST time_t *timePtr; /* Pointer to the number of seconds - * since the local system's epoch - */ + * since the local system's epoch */ { /* * Get a thread-local buffer to hold the returned time. */ - struct tm *tmPtr = (struct tm *) - Tcl_GetThreadData(&tmKey, sizeof(struct tm)); + ThreadSpecificData *tsdPtr = TCL_TSD_INIT( &tmKey ); #ifdef HAVE_GMTIME_R - gmtime_r(timePtr, tmPtr); + gmtime_r(timePtr, &( tsdPtr->gmtime_buf )); #else - Tcl_MutexLock(&tmMutex); - memcpy((VOID *) tmPtr, (VOID *) gmtime(timePtr), sizeof(struct tm)); - Tcl_MutexUnlock(&tmMutex); + Tcl_MutexLock( &tmMutex ); + memcpy( (VOID *) &( tsdPtr->gmtime_buf ), + (VOID *) gmtime( timePtr ), + sizeof( struct tm ) ); + Tcl_MutexUnlock( &tmMutex ); #endif - return tmPtr; + return &( tsdPtr->gmtime_buf ); +} +/* + * Forwarder for obsolete item in Stubs + */ +struct tm* +TclpGmtime_unix( timePtr ) + CONST time_t* timePtr; +{ + return TclpGmtime( timePtr ); } /* *---------------------------------------------------------------------- * - * ThreadSafeLocalTime -- + * TclpLocaltime -- * * Wrapper around the 'localtime' library function to make it thread * safe. @@ -408,25 +407,99 @@ ThreadSafeGMTime(timePtr) *---------------------------------------------------------------------- */ -static struct tm * -ThreadSafeLocalTime(timePtr) +struct tm * +TclpLocaltime(timePtr) CONST time_t *timePtr; /* Pointer to the number of seconds - * since the local system's epoch - */ + * since the local system's epoch */ { /* * Get a thread-local buffer to hold the returned time. */ - struct tm *tmPtr = (struct tm *) - Tcl_GetThreadData(&tmKey, sizeof(struct tm)); + ThreadSpecificData *tsdPtr = TCL_TSD_INIT( &tmKey ); + SetTZIfNecessary(); #ifdef HAVE_LOCALTIME_R - localtime_r(timePtr, tmPtr); + localtime_r( timePtr, &( tsdPtr->localtime_buf ) ); #else + Tcl_MutexLock( &tmMutex ); + memcpy( (VOID *) &( tsdPtr -> localtime_buf ), + (VOID *) localtime( timePtr ), + sizeof( struct tm ) ); + Tcl_MutexUnlock( &tmMutex ); +#endif + return &( tsdPtr->localtime_buf ); +} +/* + * Forwarder for obsolete item in Stubs + */ +struct tm* +TclpLocaltime_unix( timePtr ) + CONST time_t* timePtr; +{ + return TclpLocaltime( timePtr ); +} + +/* + *---------------------------------------------------------------------- + * + * 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() { + + CONST char* newTZ = getenv( "TZ" ); Tcl_MutexLock(&tmMutex); - memcpy((VOID *) tmPtr, (VOID *) localtime(timePtr), sizeof(struct tm)); + if ( newTZ == NULL ) { + newTZ = ""; + } + if ( lastTZ == NULL || strcmp( lastTZ, newTZ ) ) { + tzset(); + if ( lastTZ == NULL ) { + Tcl_CreateExitHandler( CleanupMemory, (ClientData) NULL ); + } else { + Tcl_Free( lastTZ ); + } + lastTZ = Tcl_Alloc( strlen( newTZ ) + 1 ); + strcpy( lastTZ, newTZ ); + } Tcl_MutexUnlock(&tmMutex); -#endif - return tmPtr; + +} + +/* + *---------------------------------------------------------------------- + * + * 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 ) +{ + Tcl_Free( lastTZ ); } |