diff options
Diffstat (limited to 'time/tzset.c')
| -rw-r--r-- | time/tzset.c | 65 |
1 files changed, 39 insertions, 26 deletions
diff --git a/time/tzset.c b/time/tzset.c index 954cec2e87..6a9ebe1f82 100644 --- a/time/tzset.c +++ b/time/tzset.c @@ -74,7 +74,7 @@ static tz_rule tz_rules[2]; static int compute_change __P ((tz_rule *rule, int year)); -int __tzset_run = 0; +static char *old_tz = NULL; /* Interpret the TZ envariable. */ void @@ -85,6 +85,20 @@ __tzset () unsigned short int hh, mm, ss; unsigned short int whichrule; + /* Examine the TZ environment variable. */ + tz = getenv ("TZ"); + + /* A leading colon means "implementation defined syntax". + We ignore the colon and always use the same algorithm: + try a data file, and if none exists parse the 1003.1 syntax. */ + if (tz && *tz == ':') + ++tz; + + /* Check whether the value changes since the last run. */ + if (old_tz != NULL && tz != NULL && strcmp (tz, old_tz) == 0) + /* No change, simply return. */ + return; + /* Free old storage. */ if (tz_rules[0].name != NULL && *tz_rules[0].name != '\0') { @@ -98,22 +112,15 @@ __tzset () tz_rules[1].name = NULL; } - /* Examine the TZ environment variable. */ - tz = getenv ("TZ"); - - /* A leading colon means "implementation defined syntax". - We ignore the colon and always use the same algorithm: - try a data file, and if none exists parse the 1003.1 syntax. */ - if (tz && *tz == ':') - ++tz; + /* Save the value of `tz'. */ + if (old_tz != NULL) + free (old_tz); + old_tz = tz ? __strdup (tz) : NULL; /* Try to read a data file. */ __tzfile_read (tz); if (__use_tzfile) - { - __tzset_run = 1; - return; - } + return; /* No data file found. Default to UTC if nothing specified. */ @@ -121,10 +128,10 @@ __tzset () { static const char UTC[] = "UTC"; size_t len = sizeof UTC; - tz_rules[0].name = (char *) malloc(len); + tz_rules[0].name = (char *) malloc (len); if (tz_rules[0].name == NULL) return; - tz_rules[1].name = (char *) malloc(len); + tz_rules[1].name = (char *) malloc (len); if (tz_rules[1].name == NULL) return; memcpy ((void *) tz_rules[0].name, UTC, len); @@ -136,7 +143,6 @@ __tzset () tz_rules[0].offset = tz_rules[1].offset = 0L; tz_rules[0].change = tz_rules[1].change = (time_t) -1; tz_rules[0].computed_for = tz_rules[1].computed_for = 0; - __tzset_run = 1; return; } @@ -147,8 +153,12 @@ __tzset () /* Get the standard timezone name. */ tz_rules[0].name = (char *) malloc (strlen (tz) + 1); if (tz_rules[0].name == NULL) - /* Don't set __tzset_run so we will try again. */ - return; + { + /* Clear the old tz name so we will try again. */ + free (old_tz); + old_tz = NULL; + return; + } if (sscanf(tz, "%[^0-9,+-]", tz_rules[0].name) != 1 || (l = strlen(tz_rules[0].name)) < 3) @@ -257,7 +267,8 @@ __tzset () tz_rules[0].offset, tz_rules[1].offset); if (__use_tzfile) { - __tzset_run = 1; + free (old_tz); + old_tz = NULL; return; } } @@ -353,8 +364,6 @@ __tzset () tzr->computed_for = -1; } - - __tzset_run = 1; } /* Maximum length of a timezone name. __tz_compute keeps this up to date @@ -365,8 +374,7 @@ size_t __tzname_cur_max; long int __tzname_max () { - if (! __tzset_run) - __tzset (); + __tzset (); return __tzname_cur_max; } @@ -450,7 +458,7 @@ compute_change (rule, year) /* T is now the Epoch-relative time of 0:00:00 GMT on the day we want. Just add the time of day and local offset from GMT, and we're done. */ - rule->change = t + rule->offset + rule->secs; + rule->change = t - rule->offset + rule->secs; rule->computed_for = year; return 1; } @@ -464,8 +472,7 @@ __tz_compute (timer, tm) time_t timer; const struct tm *tm; { - if (! __tzset_run) - __tzset (); + __tzset (); if (! compute_change (&tz_rules[0], 1900 + tm->tm_year) || ! compute_change (&tz_rules[1], 1900 + tm->tm_year)) @@ -504,6 +511,12 @@ weak_function tzset (void) { __libc_lock_lock (__tzset_lock); + __tzset (); + + /* Set `tzname'. */ + __tzname[0] = (char *) tz_rules[0].name; + __tzname[1] = (char *) tz_rules[1].name; + __libc_lock_unlock (__tzset_lock); } |