Gavin Smith <gavinsmith0...@gmail.com> writes:
> It appears you can have thread-local variables with gcc using
> "__thread", for example, "static __thread const char *encoding". (I
> don't know about other compilers.) Would something like this work? As
> well as threads, updating the cached encoding when the encoding
> changes would be a problem.
If the overhead of a single setlocale call is acceptable, how about
using the return address of setlocale as a cache key and bypass the
later part?
Something like:
diff --git a/lib/localcharset.c b/lib/localcharset.c
index b4af28c..d0e10b9 100644
--- a/lib/localcharset.c
+++ b/lib/localcharset.c
@@ -491,6 +491,8 @@ locale_charset (void)
#elif defined WINDOWS_NATIVE
static char buf[2 + 10 + 1];
+ static __thread char *cached_codeset = NULL;
+ static __thread char *cached_locale = NULL;
/* The Windows API has a function returning the locale's codepage as
a number, but the value doesn't change according to what the
@@ -500,6 +502,9 @@ locale_charset (void)
char *current_locale = setlocale (LC_ALL, NULL);
char *pdot;
+ if (current_locale == cached_locale)
+ returned cached_codeset;
+
/* If they set different locales for different categories,
'setlocale' will return a semi-colon separated list of locale
values. To make sure we use the correct one, we choose LC_CTYPE. */
@@ -609,5 +614,12 @@ locale_charset (void)
codeset = "ASCII";
#endif
+#ifdef WINDOWS_NATIVE
+ /* Cache the current locale as well as the determined codeset, so we
+ can bypass the call to GetACP and alias lookup from the next time. */
+ cached_locale = current_locale;
+ cached_codeset = codeset;
+#endif
+
return codeset;
}
Regards,
--
Daiki Ueno
