# define TIME64_TRACE3(format, var1, var2, var3) ((void)0)
#endif
+/* Set up the mutexes for this file. There are no races possible on
+ * non-threaded perls, nor platforms that naturally don't have them.
+ * Otherwise, we need to have mutexes. If we have reentrant versions of the
+ * functions below, they automatically will be substituted for the
+ * non-reentrant ones. That solves the problem of the buffers being trashed by
+ * another thread, but not of the environment or locale changing during their
+ * execution. To do that, we only need a read lock (which prevents writing by
+ * others). However, if we don't have re-entrant functions, we can gain some
+ * measure of thread-safety by using an exclusive lock during their execution.
+ * That will protect against any other use of the functions that use the
+ * mutexes, which all of core should be using. */
+#ifdef USE_REENTRANT_API /* This indicates a platform where we need reentrant
+ versions if have them */
+# ifdef PERL_REENTR_USING_LOCALTIME_R
+# define LOCALTIME_LOCK ENV_LOCALE_READ_LOCK
+# define LOCALTIME_UNLOCK ENV_LOCALE_READ_UNLOCK
+# else
+# define LOCALTIME_LOCK ENV_LOCALE_LOCK
+# define LOCALTIME_UNLOCK ENV_LOCALE_UNLOCK
+# endif
+# ifdef PERL_REENTR_USING_GMTIME_R
+# define GMTIME_LOCK ENV_LOCALE_READ_LOCK
+# define GMTIME_UNLOCK ENV_LOCALE_READ_UNLOCK
+# else
+# define GMTIME_LOCK ENV_LOCALE_LOCK
+# define GMTIME_UNLOCK ENV_LOCALE_UNLOCK
+# endif
+#else /* Reentrant not needed, so races not possible */
+# define LOCALTIME_LOCK NOOP
+# define LOCALTIME_UNLOCK NOOP
+# define GMTIME_LOCK NOOP
+# define GMTIME_UNLOCK NOOP
+#endif
+
static int S_is_exception_century(Year year)
{
const int is_exception = ((year % 100 == 0) && !(year % 400 == 0));
struct tm safe_date;
struct tm * result;
+ GMTIME_LOCK;
+
/* reentr.h will automatically replace this with a call to gmtime_r()
* when appropriate */
result = gmtime(&safe_time);
#else
/* Here, no gmtime_r() and is a threaded perl where the result can be
* overwritten by a call in another thread. Copy to a safe place,
- * hopefully before another gmtime can jump in and trash this
- * result. */
+ * hopefully before another gmtime that isn't using the mutexes can
+ * jump in and trash this result. */
memcpy(&safe_date, result, sizeof(safe_date));
result = &safe_date;
#endif
+ GMTIME_UNLOCK;
S_copy_little_tm_to_big_TM(result, p);
assert(S_check_tm(p));
p->tm_isdst = 0;
#ifdef HAS_TM_TM_ZONE
- p->tm_zone = (char *)"UTC";
+ p->tm_zone = "UTC";
#endif
v_tm_sec = (int)Perl_fmod(time, 60.0);
struct tm safe_date;
const struct tm * result;
struct TM gm_tm;
- Year orig_year;
+ Year orig_year = 0; /* initialise to avoid spurious compiler warning */
int month_diff;
const bool use_system = SHOULD_USE_SYSTEM_LOCALTIME(*time);
dTHX;
safe_time = (time_t)S_timegm64(&gm_tm);
}
+ LOCALTIME_LOCK;
+
/* reentr.h will automatically replace this with a call to localtime_r()
* when appropriate */
result = localtime(&safe_time);
- if( result == NULL ) {
+ if(UNLIKELY(result == NULL)) {
+ LOCALTIME_UNLOCK;
TIME64_TRACE1("localtime(%d) returned NULL\n", (int)safe_time);
return NULL;
}
/* Here, would be using localtime_r() if it could, meaning there isn't one,
* and is a threaded perl where the result can be overwritten by a call in
* another thread. Copy to a safe place, hopefully before another
- * localtime can jump in and trash this result. */
+ * localtime that isn't using the mutexes can jump in and trash this
+ * result. */
memcpy(&safe_date, result, sizeof(safe_date));
result = &safe_date;
#endif
+ LOCALTIME_UNLOCK;
+
S_copy_little_tm_to_big_TM(result, local_tm);
if (! use_system) {