eliminate costly tricks to avoid TLS access for current locale state

the code being removed used atomics to track whether any threads might
be using a locale other than the current global locale, and whether
any threads might have abstract 8-bit (non-UTF-8) LC_CTYPE active, a
feature which was never committed (still pending). the motivations
were to support early execution prior to setup of the thread pointer,
to partially support systems (ancient kernels) where thread pointer
setup is not possible, and to avoid high performance cost on archs
where accessing the thread pointer may be very slow.

since commit 19a1fe670acb3ab9ead0fe31859ca7d4fe40dd54, the thread
pointer is always available, so these hacks are no longer needed.
removing them greatly simplifies the affected code.

diff --git a/src/internal/libc.h b/src/internal/libc.h
index 51ee1860cd305793ed912dfc8933eef0aa7b0684..212f0e8bd8ff8263aad8821bc87420a965b0b0cd 100644 (file)
--- a/src/internal/libc.h
+++ b/src/internal/libc.h
@@ -23,8 +23,6 @@ struct __libc {
        volatile int ofl_lock[2];
        size_t tls_size;
        size_t page_size;
-       volatile int uselocale_cnt;
-       volatile int bytelocale_cnt_minus_1;
        struct __locale_struct global_locale;
 };
 

diff --git a/src/internal/locale_impl.h b/src/internal/locale_impl.h
index 9142f0c278133b44e91c19ee1a1852cc056db52b..5aebbf68866a8241e0c6aa4c3b4498496c30d1cb 100644 (file)
--- a/src/internal/locale_impl.h
+++ b/src/internal/locale_impl.h
@@ -20,11 +20,9 @@ const char *__lctrans_cur(const char *);
 #define LCTRANS(msg, lc, loc) __lctrans(msg, (loc)->cat[(lc)-2])
 #define LCTRANS_CUR(msg) __lctrans_cur(msg)
 
-#define CURRENT_LOCALE \
-       (libc.uselocale_cnt ? __pthread_self()->locale : &libc.global_locale)
+#define CURRENT_LOCALE (__pthread_self()->locale)
 
-#define CURRENT_UTF8 \
-       (libc.bytelocale_cnt_minus_1<0 || __pthread_self()->locale->ctype_utf8)
+#define CURRENT_UTF8 (__pthread_self()->locale->ctype_utf8)
 
 #undef MB_CUR_MAX
 #define MB_CUR_MAX (CURRENT_UTF8 ? 4 : 1)

diff --git a/src/locale/setlocale.c b/src/locale/setlocale.c
index 8ea389a3c118d570cbc3a0eb54d03ba52df39bf2..d797f43fe8855c3393fb41b965eaefabb578542c 100644 (file)
--- a/src/locale/setlocale.c
+++ b/src/locale/setlocale.c
@@ -55,12 +55,7 @@ char *setlocale(int cat, const char *name)
                return buf;
        }
 
-       if (name) {
-               int adj = libc.global_locale.ctype_utf8;
-               __setlocalecat(&libc.global_locale, cat, name);
-               adj -= libc.global_locale.ctype_utf8;
-               if (adj) a_fetch_add(&libc.bytelocale_cnt_minus_1, adj);
-       }
+       if (name) __setlocalecat(&libc.global_locale, cat, name);
 
        switch (cat) {
        case LC_CTYPE:

diff --git a/src/locale/uselocale.c b/src/locale/uselocale.c
index 510679575944dd1cfe04589d3e2b1b9f547c60ba..b70a0c185fb616a85b566e5ca82c5c6bf8c44207 100644 (file)
--- a/src/locale/uselocale.c
+++ b/src/locale/uselocale.c
@@ -10,15 +10,7 @@ locale_t __uselocale(locale_t new)
 
        if (new == LC_GLOBAL_LOCALE) new = global;
 
-       if (new && new != old) {
-               int adj = 0;
-               if (new == global) a_dec(&libc.uselocale_cnt);
-               else if (!new->ctype_utf8) adj++;
-               if (old == global) a_inc(&libc.uselocale_cnt);
-               else if (!old->ctype_utf8) adj--;
-               a_fetch_add(&libc.bytelocale_cnt_minus_1, adj);
-               self->locale = new;
-       }
+       self->locale = new;
 
        return old == global ? LC_GLOBAL_LOCALE : old;
 }

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 4eb8b8881d2871ed27153a506594924a9a8f90bb..de72818d778a30ae7be178096ed52e50ac3451e5 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -67,12 +67,6 @@ _Noreturn void __pthread_exit(void *result)
                exit(0);
        }
 
-       if (self->locale != &libc.global_locale) {
-               a_dec(&libc.uselocale_cnt);
-               if (self->locale->ctype_utf8)
-                       a_dec(&libc.bytelocale_cnt_minus_1);
-       }
-
        /* Process robust list in userspace to handle non-pshared mutexes
         * and the detached thread case where the robust list head will
         * be invalid when the kernel would process it. */