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-rw-r--r--unix/tclUnixTime.c251
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 );
}