libs/posix: Implemented new locale functions

Implemented the missing POSIX functions in <locale.h>:
newlocale, duplocale, uselocale, and freelocale, and also
provided missing type definitions for <locale.h>.

Implemented missing POSIX locale-based function variants.

Modified LocaleBackend so that it could support thread-local
locales.

Some glibc-like locale-related variables supporting
ctype and printf family of functions have also been updated
to reflect the thread-local variables present in the latest
glibc sources.

As there have been some modifications to global symbols
in libroot, libroot_stubs.c has been regenerated.

Bug: #17168
Change-Id: Ibf296c58c47d42d1d1dfb2ce64042442f2679431
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5351
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>

headers/posix/ctype.h

@@ -6,6 +6,9 @@
 #define _CTYPE_H
 
 
+#include <locale_t.h>
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -27,6 +30,22 @@ int toascii(int);
 int tolower(int);
 int toupper(int);
 
+
+int isalnum_l(int, locale_t);
+int isalpha_l(int, locale_t);
+int isblank_l(int, locale_t);
+int iscntrl_l(int, locale_t);
+int isdigit_l(int, locale_t);
+int isgraph_l(int, locale_t);
+int islower_l(int, locale_t);
+int isprint_l(int, locale_t);
+int ispunct_l(int, locale_t);
+int isspace_l(int, locale_t);
+int isupper_l(int, locale_t);
+int isxdigit_l(int, locale_t);
+int tolower_l(int, locale_t);
+int toupper_l(int, locale_t);
+
 enum {
 	_ISblank = 0x0001,		/* blank */
 	_IScntrl = 0x0002,		/* control */
@@ -48,14 +67,19 @@ extern const unsigned short int *__ctype_b;
 extern const int *__ctype_tolower;
 extern const int *__ctype_toupper;
 
+extern const unsigned short int **__ctype_b_loc();
+extern const int **__ctype_tolower_loc();
+extern const int **__ctype_toupper_loc();
+
 #define __isctype(c, type) \
-	(__ctype_b[(int)(c)] & (unsigned short int)type)
+	((*__ctype_b_loc())[(int)(c)] & (unsigned short int)type)
+
+#define tolower(c) ((int)(*__ctype_tolower_loc())[(int)(c)])
+#define toupper(c) ((int)(*__ctype_toupper_loc())[(int)(c)])
 
 #define isascii(c) (((c) & ~0x7f) == 0)	/* ASCII characters have bit 8 cleared */
 #define toascii(c) ((c) & 0x7f)			/* Clear higher bits */
 
-#define tolower(c) ((int)__ctype_tolower[(int)(c)])
-#define toupper(c) ((int)__ctype_toupper[(int)(c)])
 #define _tolower(c)	tolower(c)
 #define _toupper(c)	toupper(c)
 

headers/posix/langinfo.h

@@ -145,6 +145,7 @@ enum {
 __BEGIN_DECLS
 
 extern char*	nl_langinfo(nl_item item);
+extern char*	nl_langinfo_l(nl_item item, locale_t locale);
 
 __END_DECLS
 

headers/posix/locale.h

@@ -6,6 +6,7 @@
 #define _LOCALE_H_
 
 
+#include <locale_t.h>
 #include <null.h>
 
 struct lconv {
@@ -48,6 +49,19 @@ struct lconv {
  */
 #define	LC_LAST		LC_MESSAGES
 
+#define LC_COLLATE_MASK		(1 << (LC_COLLATE - 1))
+#define LC_CTYPE_MASK		(1 << (LC_CTYPE - 1))
+#define LC_MONETARY_MASK	(1 << (LC_MONETARY - 1))
+#define LC_NUMERIC_MASK 	(1 << (LC_NUMERIC - 1))
+#define LC_TIME_MASK		(1 << (LC_TIME - 1))
+#define LC_MESSAGES_MASK	(1 << (LC_MESSAGES - 1))
+
+#define LC_ALL_MASK			(LC_COLLATE_MASK | LC_CTYPE_MASK | \
+							LC_MONETARY_MASK | LC_NUMERIC_MASK | \
+							LC_TIME_MASK | LC_MESSAGES_MASK)
+
+#define LC_GLOBAL_LOCALE ((locale_t)-1)
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -55,6 +69,11 @@ extern "C" {
 extern struct lconv *localeconv(void);
 extern char *setlocale(int category, const char *locale);
 
+extern locale_t duplocale(locale_t);
+extern void freelocale(locale_t);
+extern locale_t newlocale(int, const char *, locale_t);
+extern locale_t uselocale(locale_t);
+
 #ifdef __cplusplus
 }
 #endif

headers/posix/locale_t.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2022 Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _LOCALE_T_H_
+#define _LOCALE_T_H_
+
+
+typedef void* locale_t;
+
+
+#endif

headers/posix/monetary.h

@@ -6,7 +6,7 @@
 #define _MONETARY_H_
 
 
-#include <locale.h>
+#include <locale_t.h>
 #include <stddef.h>
 #include <sys/cdefs.h>
 #include <sys/types.h>
@@ -15,6 +15,7 @@
 __BEGIN_DECLS
 
 extern ssize_t strfmon(char* s, size_t maxsize, const char* format, ...);
+extern ssize_t strfmon_l(char* s, size_t maxsize, locale_t locale, const char* format, ...);
 
 __END_DECLS
 

headers/posix/string.h

@@ -6,6 +6,7 @@
 #define _STRING_H_
 
 
+#include <locale_t.h>
 #include <sys/types.h>
 
 
@@ -74,6 +75,11 @@ extern char		*strupr(char *string);
 
 extern const char	*strsignal(int signum);
 
+/* locale versions of string functions */
+extern int		strcoll_l(const char *string1, const char *string2, locale_t locale);
+extern char		*strerror_l(int errorCode, locale_t locale);
+extern size_t	strxfrm_l(char *string1, const char *string2, size_t length, locale_t locale);
+
 /* for compatibility, pull in functions declared in strings.h */
 #include <strings.h>
 

headers/posix/strings.h

@@ -6,6 +6,7 @@
 #define _STRINGS_H_
 
 
+#include <locale_t.h>
 #include <sys/types.h>
 
 
@@ -19,6 +20,10 @@ extern int		strcasecmp(const char *string1, const char *string2);
 extern int		strncasecmp(const char *string1, const char *string2,
 	size_t length);
 
+extern int		strcasecmp_l(const char *string1, const char *string2, locale_t locale);
+extern int		strncasecmp_l(const char *string1, const char *string2,
+	size_t length, locale_t locale);
+
 /* legacy compatibility -- might be removed one day */
 #define bcmp(a, b, length) memcmp((a), (b), (length))
 #define bcopy(source, dest, length) memmove((dest), (source), (length))

headers/posix/time.h

@@ -6,6 +6,7 @@
 #define _TIME_H_
 
 
+#include <locale_t.h>
 #include <sys/types.h>
 
 
@@ -92,6 +93,8 @@ extern struct tm	*localtime_r(const time_t *timer, struct tm *tm);
 extern int			nanosleep(const struct timespec *, struct timespec *);
 extern size_t		strftime(char *buffer, size_t maxSize, const char *format,
 						const struct tm *tm);
+extern size_t		strftime_l(char *buffer, size_t maxSize, const char *format,
+						const struct tm *tm, locale_t locale);
 extern char 		*strptime(const char *buf, const char *format, struct tm *tm);
 
 /* clock functions */

headers/posix/wchar.h

@@ -7,6 +7,7 @@
 
 
 #include <limits.h>
+#include <locale.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <time.h>
@@ -93,6 +94,7 @@ extern wchar_t	*wcpcpy(wchar_t *dest, const wchar_t *src);
 extern wchar_t	*wcpncpy(wchar_t *dest, const wchar_t *src, size_t srcLength);
 extern size_t   wcrtomb(char *dest, wchar_t wc, mbstate_t *mbState);
 extern int		wcscasecmp(const wchar_t *wcs1, const wchar_t *wcs2);
+extern int		wcscasecmp_l(const wchar_t *wcs1, const wchar_t *wcs2, locale_t locale);
 extern wchar_t	*wcscat(wchar_t *dest, const wchar_t *src);
 extern wchar_t	*wcschr(const wchar_t *wcs, wchar_t wc);
 #ifdef _GNU_SOURCE
@@ -100,6 +102,7 @@ extern wchar_t	*wcschrnul(const wchar_t *wcs, wchar_t wc);
 #endif
 extern int      wcscmp(const wchar_t *wcs1, const wchar_t *wcs2);
 extern int      wcscoll(const wchar_t *wcs1, const wchar_t *wcs2);
+extern int		wcscoll_l(const wchar_t *wcs1, const wchar_t *wcs2, locale_t locale);
 extern wchar_t	*wcscpy(wchar_t *dest, const wchar_t *src);
 extern size_t	wcscspn(const wchar_t *wcs, const wchar_t *reject);
 extern wchar_t	*wcsdup(const wchar_t *wcs);
@@ -110,6 +113,8 @@ extern size_t	wcslcpy(wchar_t *dest, const wchar_t *src, size_t maxLength);
 extern size_t	wcslen(const wchar_t *wcs);
 extern int		wcsncasecmp(const wchar_t *wcs1, const wchar_t *wcs2,
 					size_t maxLength);
+extern int		wcsncasecmp_l(const wchar_t *wcs1, const wchar_t *wcs2,
+					size_t maxLength, locale_t locale);
 extern wchar_t 	*wcsncat(wchar_t *dest, const wchar_t *src, size_t srcLength);
 extern int		wcsncmp(const wchar_t *wcs1, const wchar_t *wcs2,
 					size_t length);
@@ -136,6 +141,8 @@ extern unsigned long long	wcstoull(const wchar_t *wcs, wchar_t **endPtr,
 extern wchar_t	*wcswcs(const wchar_t *haystack, const wchar_t *needle);
 extern int		wcswidth(const wchar_t *wcs, size_t length);
 extern size_t	wcsxfrm(wchar_t *dest, const wchar_t *src, size_t destLength);
+extern size_t	wcsxfrm_l(wchar_t *dest, const wchar_t *src, size_t destLength,
+					locale_t locale);
 extern int		wctob(wint_t wc);
 extern int		wcwidth(wchar_t wc);
 extern wchar_t	*wmemchr(const wchar_t *wcs, wchar_t wc, size_t n);

headers/posix/wctype.h

@@ -6,6 +6,7 @@
 #define _WCTYPE_H_
 
 
+#include <locale.h>
 #include <wchar.h>
 
 typedef int wctrans_t;
@@ -36,6 +37,29 @@ extern wint_t	towupper(wint_t wc);
 extern wctrans_t wctrans(const char *charClass);
 extern wctype_t	wctype(const char *property);
 
+
+extern int		iswalnum_l(wint_t wc, locale_t locale);
+extern int		iswalpha_l(wint_t wc, locale_t locale);
+extern int		iswcntrl_l(wint_t wc, locale_t locale);
+extern int		iswctype_l(wint_t wc, wctype_t desc, locale_t locale);
+extern int		iswdigit_l(wint_t wc, locale_t locale);
+extern int		iswgraph_l(wint_t wc, locale_t locale);
+extern int		iswlower_l(wint_t wc, locale_t locale);
+extern int		iswprint_l(wint_t wc, locale_t locale);
+extern int		iswpunct_l(wint_t wc, locale_t locale);
+extern int		iswspace_l(wint_t wc, locale_t locale);
+extern int		iswupper_l(wint_t wc, locale_t locale);
+extern int		iswxdigit_l(wint_t wc, locale_t locale);
+
+extern int		iswblank_l(wint_t wc, locale_t locale);
+
+extern wint_t	towctrans_l(wint_t wc, wctrans_t transition, locale_t locale);
+extern wint_t	towlower_l(wint_t wc, locale_t locale);
+extern wint_t	towupper_l(wint_t wc, locale_t locale);
+
+extern wctrans_t wctrans_l(const char *charClass, locale_t locale);
+extern wctype_t	wctype_l(const char *property, locale_t locale);
+
 #ifdef __cplusplus
 }
 #endif

headers/private/libroot/locale/LocaleBackend.h

@@ -8,11 +8,11 @@
 
 #include <SupportDefs.h>
 
+#include <locale.h>
 #include <time.h>
 #include <wctype.h>
 
 
-struct lconv;
 struct lc_time_t;
 struct locale_data;		// glibc
 
@@ -22,29 +22,38 @@ namespace Libroot {
 
 
 struct LocaleCtypeDataBridge {
-	const unsigned short**	addrOfClassInfoTable;
-	const int**				addrOfToLowerTable;
-	const int**				addrOfToUpperTable;
+private:
+	const unsigned short*		localClassInfoTable;
+	const int*					localToLowerTable;
+	const int*					localToUpperTable;
 
-	const unsigned short*	posixClassInfo;
-	const int*				posixToLowerMap;
-	const int*				posixToUpperMap;
+public:
+	const unsigned short**		addrOfClassInfoTable;
+	const int**					addrOfToLowerTable;
+	const int**					addrOfToUpperTable;
 
-	LocaleCtypeDataBridge();
+	const unsigned short* const	posixClassInfo;
+	const int* const			posixToLowerMap;
+	const int* const			posixToUpperMap;
+
+	bool						isGlobal;
+
+	LocaleCtypeDataBridge(bool isGlobal);
 
 	void setMbCurMax(unsigned short mbCurMax);
+	void ApplyToCurrentThread();
 };
 
 
 struct LocaleMessagesDataBridge {
-	const char** posixLanginfo;
+	const char** const 	posixLanginfo;
 
 	LocaleMessagesDataBridge();
 };
 
 
 struct LocaleMonetaryDataBridge {
-	const struct lconv* posixLocaleConv;
+	const struct lconv* const posixLocaleConv;
 
 	LocaleMonetaryDataBridge();
 };
@@ -71,29 +80,42 @@ private:
 		values[6];
 	};
 	locale_data* originalGlibcLocale;
+	GlibcNumericLocale  		glibcNumericLocaleData;
 
 public:
-	const struct lconv* posixLocaleConv;
-	GlibcNumericLocale  glibcNumericLocale;
+	const struct lconv* const 	posixLocaleConv;
+	GlibcNumericLocale*  		glibcNumericLocale;
+	bool						isGlobal;
 
-	LocaleNumericDataBridge();
+	LocaleNumericDataBridge(bool isGlobal);
 	~LocaleNumericDataBridge();
+
+	void ApplyToCurrentThread();
 };
 
 
 struct LocaleTimeDataBridge {
-	const struct lc_time_t* posixLCTimeInfo;
+	const struct lc_time_t* const posixLCTimeInfo;
 
 	LocaleTimeDataBridge();
 };
 
 
 struct TimeConversionDataBridge {
+private:
+	int						localDaylight;
+	long					localTimezone;
+	char*					localTZName[2];
+	char					localTZName0[64];
+	char					localTZName1[64];
+
+public:
 	int*					addrOfDaylight;
 	long*					addrOfTimezone;
 	char**					addrOfTZName;
+	bool					isGlobal;
 
-	TimeConversionDataBridge();
+	TimeConversionDataBridge(bool isGlobal);
 };
 
 
@@ -104,9 +126,12 @@ struct LocaleDataBridge {
 	LocaleNumericDataBridge		numericDataBridge;
 	LocaleTimeDataBridge		timeDataBridge;
 	TimeConversionDataBridge	timeConversionDataBridge;
-	const char**				posixLanginfo;
+	const char** const			posixLanginfo;
+	bool						isGlobal;
 
-	LocaleDataBridge();
+	LocaleDataBridge(bool isGlobal);
+
+	void ApplyToCurrentThread();
 };
 
 
@@ -162,12 +187,25 @@ public:
 	virtual void				Initialize(LocaleDataBridge* dataBridge) = 0;
 
 	static	status_t			LoadBackend();
+	static  LocaleBackend*		CreateBackend();
+	static  void				DestroyBackend(LocaleBackend* instance);
 };
 
 
-extern LocaleBackend* gLocaleBackend;
+// The real struct behind locale_t
+struct LocaleBackendData {
+	int magic;
+	LocaleBackend* backend;
+	LocaleDataBridge* databridge;
+};
 
 
+LocaleBackendData* GetCurrentLocaleInfo();
+void SetCurrentLocaleInfo(LocaleBackendData* newLocale);
+LocaleBackend* GetCurrentLocaleBackend();
+extern LocaleBackend* gGlobalLocaleBackend;
+extern LocaleDataBridge gGlobalLocaleDataBridge;
+
 }	// namespace Libroot
 }	// namespace BPrivate
 

headers/private/libroot/locale/ThreadLocale.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#ifndef _THREAD_LOCALE_H
+#define _THREAD_LOCALE_H
+
+
+#include "LocaleBackend.h"
+
+
+namespace BPrivate {
+namespace Libroot {
+
+
+// This struct is taken from glibc's __locale_struct
+// from xlocale.h.
+// It will also be used by glibc so it should have the same
+// layout.
+struct GlibcLocaleStruct {
+    void *__locales[7]; /* 7 = __LC_LAST. */
+
+    const unsigned short int *__ctype_b;
+    const int *__ctype_tolower;
+    const int *__ctype_toupper;
+};
+
+
+// Taken from glibc's bits/locale.h
+// glibc uses different codes from our the native locale.h.
+// This should be the values used for the indexes
+// in GlibcLocaleStruct.
+enum {
+    GLIBC_LC_CTYPE = 0,
+    GLIBC_LC_NUMERIC = 1,
+    GLIBC_LC_TIME = 2,
+    GLIBC_LC_COLLATE = 3,
+    GLIBC_LC_MONETARY = 4,
+    GLIBC_LC_MESSAGES = 5,
+    GLIBC_LC_ALL = 6,
+};
+
+
+// The pointer in the TLS will point to this struct.
+struct ThreadLocale {
+    GlibcLocaleStruct   glibcLocaleStruct;
+    LocaleBackendData*  threadLocaleInfo;
+};
+
+
+ThreadLocale* GetCurrentThreadLocale();
+
+
+}	// namespace Libroot
+}	// namespace BPrivate
+
+
+#endif	// _THREAD_LOCALE_H

headers/private/libroot/time/timelocal.h

@@ -29,6 +29,7 @@
 #define	_TIMELOCAL_H_
 
 
+#include <locale.h>
 #include <sys/cdefs.h>
 
 
@@ -54,6 +55,7 @@ struct lc_time_t {
 
 __BEGIN_DECLS
 const struct lc_time_t* __get_current_time_locale(void);
+const struct lc_time_t* __get_time_locale(locale_t);
 __END_DECLS
 
 

headers/private/libroot/wchar_private.h

@@ -33,11 +33,15 @@ extern wchar_t	*__wcpcpy(wchar_t *dest, const wchar_t *src);
 extern wchar_t	*__wcpncpy(wchar_t *dest, const wchar_t *src, size_t srcLength);
 extern size_t   __wcrtomb(char *dest, wchar_t wc, mbstate_t *mbState);
 extern int		__wcscasecmp(const wchar_t *wcs1, const wchar_t *wcs2);
+extern int		__wcscasecmp_l(const wchar_t *wcs1, const wchar_t *wcs2,
+					locale_t locale);
 extern wchar_t	*__wcscat(wchar_t *dest, const wchar_t *src);
 extern wchar_t	*__wcschr(const wchar_t *wcs, wchar_t wc);
 extern wchar_t	*__wcschrnul(const wchar_t *wcs, wchar_t wc);
 extern int      __wcscmp(const wchar_t *wcs1, const wchar_t *wcs2);
 extern int      __wcscoll(const wchar_t *wcs1, const wchar_t *wcs2);
+extern int      __wcscoll_l(const wchar_t *wcs1, const wchar_t *wcs2,
+					locale_t locale);
 extern wchar_t	*__wcscpy(wchar_t *dest, const wchar_t *src);
 extern size_t	__wcscspn(const wchar_t *wcs, const wchar_t *reject);
 extern wchar_t	*__wcsdup(const wchar_t *wcs);
@@ -48,6 +52,8 @@ extern size_t	__wcslcpy(wchar_t *dest, const wchar_t *src, size_t maxLength);
 extern size_t	__wcslen(const wchar_t *wcs);
 extern int		__wcsncasecmp(const wchar_t *wcs1, const wchar_t *wcs2,
 					size_t maxLength);
+extern int		__wcsncasecmp_l(const wchar_t *wcs1, const wchar_t *wcs2,
+					size_t maxLength, locale_t locale);
 extern wchar_t 	*__wcsncat(wchar_t *dest, const wchar_t *src, size_t srcLength);
 extern int		__wcsncmp(const wchar_t *wcs1, const wchar_t *wcs2,
 					size_t length);
@@ -76,6 +82,8 @@ extern int		__wctomb(char *string, wchar_t wc);
 extern wchar_t	*__wcswcs(const wchar_t *haystack, const wchar_t *needle);
 extern int		__wcswidth(const wchar_t *wcs, size_t length);
 extern size_t	__wcsxfrm(wchar_t *dest, const wchar_t *src, size_t destLength);
+extern size_t	__wcsxfrm_l(wchar_t *dest, const wchar_t *src, size_t destLength,
+					locale_t locale);
 extern int		__wctob(wint_t wc);
 extern int		__wcwidth(wchar_t wc);
 extern wchar_t	*__wmemchr(const wchar_t *wcs, wchar_t wc, size_t n);

headers/private/system/tls.h

@@ -21,6 +21,7 @@ enum {
 	TLS_ON_EXIT_THREAD_SLOT,
 	TLS_USER_THREAD_SLOT,
 	TLS_DYNAMIC_THREAD_VECTOR,
+	TLS_LOCALE_SLOT,
 
 	// Note: these entries can safely be changed between
 	// releases; 3rd party code always calls tls_allocate()

src/libs/stdc++/legacy/Jamfile

@@ -21,7 +21,9 @@ for architectureObject in [ MultiArchSubDirSetup x86_gcc2 ] {
 			= [ FDirName $(HAIKU_TOP) src system libroot posix glibc ] ;
 		SYSHDRS =
 			$(SUBDIR)
+			[ FDirName $(glibcDir) ctype ]
 			[ FDirName $(glibcDir) libio ]
+			[ FDirName $(glibcDir) locale ]
 			[ FDirName $(glibcDir) stdlib ]
 			[ FDirName $(glibcDir) stdio-common ]
 			[ FDirName $(glibcDir) include ]

src/system/boot/Jamfile

@@ -306,6 +306,8 @@ for platform in [ MultiBootSubDirSetup ] {
 
 		BootMergeObject boot_libroot_$(platform:G=).o :
 			abs.c
+			ctype_loc.cpp
+			ctype_l.cpp
 			ctype.cpp
 			LocaleData.cpp
 			qsort.c

src/system/kernel/lib/Jamfile

@@ -64,6 +64,8 @@ KernelMergeObject kernel_lib_posix.o :
 	poll.cpp
 	utime.c
 	# locale
+	ctype_loc.cpp
+	ctype_l.cpp
 	ctype.cpp
 	localeconv.cpp
 	LocaleData.cpp

src/system/libroot/add-ons/icu/ICULocaleBackend.cpp

@@ -30,6 +30,13 @@ CreateInstance()
 }
 
 
+extern "C" void
+DestroyInstance(LocaleBackend* instance)
+{
+	delete instance;
+}
+
+
 ICULocaleBackend::ICULocaleBackend()
 	:
 	fThreadLocalStorageKey(_CreateThreadLocalStorageKey()),

src/system/libroot/add-ons/icu/ICUNumericData.cpp

@@ -34,9 +34,9 @@ ICUNumericData::ICUNumericData(pthread_key_t tlsKey, struct lconv& localeConv)
 void
 ICUNumericData::Initialize(LocaleNumericDataBridge* dataBridge)
 {
-	dataBridge->glibcNumericLocale.values[0].string = fDecimalPoint;
-	dataBridge->glibcNumericLocale.values[1].string = fThousandsSep;
-	dataBridge->glibcNumericLocale.values[2].string = fGrouping;
+	dataBridge->glibcNumericLocale->values[0].string = fDecimalPoint;
+	dataBridge->glibcNumericLocale->values[1].string = fThousandsSep;
+	dataBridge->glibcNumericLocale->values[2].string = fGrouping;
 	fDataBridge = dataBridge;
 }
 
@@ -62,13 +62,13 @@ ICUNumericData::SetTo(const Locale& locale, const char* posixLocaleName)
 		if (result == B_OK) {
 			result = _SetLocaleconvEntry(formatSymbols, fDecimalPoint,
 				DecimalFormatSymbols::kDecimalSeparatorSymbol);
-			fDataBridge->glibcNumericLocale.values[3].word
+			fDataBridge->glibcNumericLocale->values[3].word
 				= (unsigned int)fDecimalPoint[0];
 		}
 		if (result == B_OK) {
 			result = _SetLocaleconvEntry(formatSymbols, fThousandsSep,
 				DecimalFormatSymbols::kGroupingSeparatorSymbol);
-			fDataBridge->glibcNumericLocale.values[4].word
+			fDataBridge->glibcNumericLocale->values[4].word
 				= (unsigned int)fThousandsSep[0];
 		}
 		if (result == B_OK) {
@@ -104,9 +104,9 @@ ICUNumericData::SetToPosix()
 		strcpy(fDecimalPoint, fDataBridge->posixLocaleConv->decimal_point);
 		strcpy(fThousandsSep, fDataBridge->posixLocaleConv->thousands_sep);
 		strcpy(fGrouping, fDataBridge->posixLocaleConv->grouping);
-		fDataBridge->glibcNumericLocale.values[3].word
+		fDataBridge->glibcNumericLocale->values[3].word
 			= (unsigned int)fDecimalPoint[0];
-		fDataBridge->glibcNumericLocale.values[4].word
+		fDataBridge->glibcNumericLocale->values[4].word
 			= (unsigned int)fThousandsSep[0];
 	}
 

src/system/libroot/add-ons/icu/ICUTimeConversion.cpp

@@ -47,6 +47,7 @@ status_t
 ICUTimeConversion::TZSet(const char* timeZoneID, const char* tz)
 {
 	bool offsetHasBeenSet = false;
+	bool timeZoneIdMatches = false;
 
 	// The given TZ environment variable's content overrides the default
 	// system timezone.
@@ -55,8 +56,10 @@ ICUTimeConversion::TZSet(const char* timeZoneID, const char* tz)
 		// value is implementation specific, we expect a full timezone ID.
 		if (*tz == ':') {
 			// nothing to do if the given name matches the current timezone
-			if (strcasecmp(fTimeZoneID, tz + 1) == 0)
-				return B_OK;
+			if (strcasecmp(fTimeZoneID, tz + 1) == 0) {
+				timeZoneIdMatches = true;
+				goto done;
+			}
 
 			strlcpy(fTimeZoneID, tz + 1, sizeof(fTimeZoneID));
 		} else {
@@ -64,8 +67,10 @@ ICUTimeConversion::TZSet(const char* timeZoneID, const char* tz)
 			strlcpy(fTimeZoneID, tz, sizeof(fTimeZoneID));
 
 			// nothing to do if the given name matches the current timezone
-			if (strcasecmp(fTimeZoneID, fDataBridge->addrOfTZName[0]) == 0)
-				return B_OK;
+			if (strcasecmp(fTimeZoneID, fDataBridge->addrOfTZName[0]) == 0) {
+				timeZoneIdMatches = true;
+				goto done;
+			}
 
 			// parse TZ variable (only <std> and <offset> supported)
 			const char* tzNameEnd = tz;
@@ -88,12 +93,21 @@ ICUTimeConversion::TZSet(const char* timeZoneID, const char* tz)
 		}
 	} else {
 		// nothing to do if the given name matches the current timezone
-		if (strcasecmp(fTimeZoneID, timeZoneID) == 0)
-			return B_OK;
+		if (strcasecmp(fTimeZoneID, timeZoneID) == 0) {
+			timeZoneIdMatches = true;
+			goto done;
+		}
 
 		strlcpy(fTimeZoneID, timeZoneID, sizeof(fTimeZoneID));
 	}
 
+done:
+	// fTimeZone can still be NULL if we don't initialize it
+	// in the first TZSet, causing problems for future
+	// Localtime invocations.
+	if (fTimeZone != NULL && timeZoneIdMatches)
+		return B_OK;
+
 	delete fTimeZone;
 	fTimeZone = TimeZone::createTimeZone(fTimeZoneID);
 	if (fTimeZone == NULL)

src/system/libroot/posix/glibc/ctype/ctype.h

@@ -64,6 +64,11 @@ enum
 /* These are defined in ctype-info.c.
    The declarations here must match those in localeinfo.h.
 
+   In the thread-specific locale model (see `uselocale' in <locale.h>)
+   we cannot use global variables for these as was done in the past.
+   Instead, the following accessor functions return the address of
+   each variable, which is local to the current thread if multithreaded.
+
    These point into arrays of 384, so they can be indexed by any `unsigned
    char' value [0,255]; by EOF (-1); or by any `signed char' value
    [-128,-1).  ISO C requires that the ctype functions work for `unsigned
@@ -72,12 +77,12 @@ enum
    rather than `unsigned char's because tolower (EOF) must be EOF, which
    doesn't fit into an `unsigned char'.  But today more important is that
    the arrays are also used for multi-byte character sets.  */
-extern __const unsigned short int *__ctype_b;	/* Characteristics.  */
-extern __const __int32_t *__ctype_tolower; /* Case conversions.  */
-extern __const __int32_t *__ctype_toupper; /* Case conversions.  */
+extern __const unsigned short int **__ctype_b_loc (void); /* Characteristics. */
+extern __const __int32_t **__ctype_tolower_loc (void);    /* Case conversions. */
+extern __const __int32_t **__ctype_toupper_loc (void);    /* Case conversions. */
 
 #define	__isctype(c, type) \
-  (__ctype_b[(int) (c)] & (unsigned short int) type)
+  ((*__ctype_b_loc())[(int) (c)] & (unsigned short int) type)
 
 #define	__isascii(c)	(((c) & ~0x7f) == 0)	/* If C is a 7 bit value.  */
 #define	__toascii(c)	((c) & 0x7f)		/* Mask off high bits.  */
@@ -167,27 +172,27 @@ __exctype (_tolower);
 __extern_inline int
 tolower (int __c) __THROW
 {
-  return __c >= -128 && __c < 256 ? __ctype_tolower[__c] : __c;
+  return __c >= -128 && __c < 256 ? (*__ctype_tolower_loc())[__c] : __c;
 }
 
 __extern_inline int
 toupper (int __c) __THROW
 {
-  return __c >= -128 && __c < 256 ? __ctype_toupper[__c] : __c;
+  return __c >= -128 && __c < 256 ? (*__ctype_toupper_loc())[__c] : __c;
 }
 # endif
 
 # if __GNUC__ >= 2 && defined __OPTIMIZE__ && !defined __cplusplus
-#  define tolower(c) __tobody (c, tolower, __ctype_tolower, (c))
-#  define toupper(c) __tobody (c, toupper, __ctype_toupper, (c))
+#  define tolower(c) __tobody (c, tolower, (*__ctype_tolower_loc()), (c))
+#  define toupper(c) __tobody (c, toupper, (*__ctype_toupper_loc()), (c))
 # endif	/* Optimizing gcc */
 
 # if defined __USE_SVID || defined __USE_MISC || defined __USE_XOPEN
 #  define isascii(c)	__isascii (c)
 #  define toascii(c)	__toascii (c)
 
-#  define _tolower(c)	((int) __ctype_tolower[(int) (c)])
-#  define _toupper(c)	((int) __ctype_toupper[(int) (c)])
+#  define _tolower(c)	((int) (*__ctype_tolower_loc())[(int) (c)])
+#  define _toupper(c)	((int) (*__ctype_toupper_loc())[(int) (c)])
 # endif
 
 #endif /* Not __NO_CTYPE.  */

src/system/libroot/posix/glibc/extensions/Jamfile

@@ -10,6 +10,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include arch
 			generic ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include ;
+		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ctype ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc libio ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc locale ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ;

src/system/libroot/posix/glibc/locale/Jamfile

@@ -13,6 +13,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			generic ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc locale ;
+		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ctype ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ;
 
 		MergeObject <$(architecture)>posix_gnu_locale.o :
@@ -24,6 +25,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			C-time.c
 			C_name.c
 			coll-lookup.c
+			global-locale.c
 			lc-collate.c
 			lc-ctype.c
 			lc-messages.c

src/system/libroot/posix/glibc/locale/global-locale.c

@@ -0,0 +1,48 @@
+/* Locale object representing the global locale controlled by setlocale.
+   Copyright (C) 2002-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <locale.h>
+#include "localeinfo.h"
+
+#define DEFINE_CATEGORY(category, category_name, items, a) \
+extern struct locale_data _nl_C_##category;
+#include "categories.def"
+#undef        DEFINE_CATEGORY
+
+/* Defined in locale/C-ctype.c.  */
+extern const char _nl_C_LC_CTYPE_class[];
+extern const char _nl_C_LC_CTYPE_toupper[];
+extern const char _nl_C_LC_CTYPE_tolower[];
+
+/* Here we define the locale object maintained by setlocale.
+   The references in the initializer are weak, so the parts of
+   the structure that are never referred to will be zero.  */
+
+struct __locale_struct _nl_global_locale =
+  {
+    .__locales =
+    {
+#define DEFINE_CATEGORY(category, category_name, items, a) \
+      [category] = &_nl_C_##category,
+#include "categories.def"
+#undef        DEFINE_CATEGORY
+    },
+    .__ctype_b = (const unsigned short int *) _nl_C_LC_CTYPE_class + 128,
+    .__ctype_tolower = (const int *) _nl_C_LC_CTYPE_tolower + 128,
+    .__ctype_toupper = (const int *) _nl_C_LC_CTYPE_toupper + 128
+  };

src/system/libroot/posix/glibc/locale/lc-ctype.c

@@ -47,9 +47,9 @@ _nl_postload_ctype (void)
 
   offset = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_CLASS_OFFSET);
   for (cnt = 0; cnt < 12; cnt++)
-    __ctype32_wctype[cnt] = _nl_current_LC_CTYPE->values[offset + cnt].string;
+    __ctype32_wctype[cnt] = _nl_global_locale.__locales[LC_CTYPE]->values[offset + cnt].string;
 
   offset = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_OFFSET);
   for (cnt = 0; cnt < 2; cnt++)
-    __ctype32_wctrans[cnt] = _nl_current_LC_CTYPE->values[offset + cnt].string;
+    __ctype32_wctrans[cnt] = _nl_global_locale.__locales[LC_CTYPE]->values[offset + cnt].string;
 }

src/system/libroot/posix/glibc/locale/localeinfo.h

@@ -27,6 +27,11 @@
 #include <stdint.h>
 #include <sys/types.h>
 
+// __locale_struct
+#include <xlocale.h>
+// LC_* values
+#include <locale.h>
+
 /* This has to be changed whenever a new locale is defined.  */
 #define __LC_LAST	7
 
@@ -141,12 +146,6 @@ enum
   (((((const uint32_t *) (desc)) - 8)[(c) >> 5] >> ((c) & 0x1f)) & 1)
 
 
-/* For each category declare the variable for the current locale data.  */
-#define DEFINE_CATEGORY(category, category_name, items, a) \
-extern struct locale_data *_nl_current_##category;
-#include "categories.def"
-#undef	DEFINE_CATEGORY
-
 extern const char *const _nl_category_names[__LC_LAST];
 extern const size_t _nl_category_name_sizes[__LC_LAST];
 extern struct locale_data * *const _nl_current[__LC_LAST];
@@ -158,22 +157,33 @@ extern const char _nl_POSIX_name[];
 /* The standard codeset.  */
 extern const char _nl_C_codeset[];
 
+/* This is the internal locale_t object that holds the global locale
+   controlled by calls to setlocale.  A thread's TSD locale pointer
+   points to this when `uselocale (LC_GLOBAL_LOCALE)' is in effect.  */
+extern struct __locale_struct _nl_global_locale;
+
+extern struct __locale_struct* _nl_current_locale();
+#define _NL_CURRENT_LOCALE        (_nl_current_locale())
+
+/* Return a pointer to the current `struct __locale_data' for CATEGORY.  */
+#define _NL_CURRENT_DATA(category) \
+  (_NL_CURRENT_LOCALE->__locales[category])
+
 /* Extract the current CATEGORY locale's string for ITEM.  */
 #define _NL_CURRENT(category, item) \
-  (_nl_current_##category->values[_NL_ITEM_INDEX (item)].string)
+  (_NL_CURRENT_DATA (category)->values[_NL_ITEM_INDEX (item)].string)
 
 /* Extract the current CATEGORY locale's string for ITEM.  */
 #define _NL_CURRENT_WSTR(category, item) \
-  ((wchar_t *) (_nl_current_##category->values[_NL_ITEM_INDEX (item)].wstr))
+  ((wchar_t *) _NL_CURRENT_DATA (category)->values[_NL_ITEM_INDEX (item)].wstr)
 
 /* Extract the current CATEGORY locale's word for ITEM.  */
 #define _NL_CURRENT_WORD(category, item) \
-  (_nl_current_##category->values[_NL_ITEM_INDEX (item)].word)
+  ((uint32_t) _NL_CURRENT_DATA (category)->values[_NL_ITEM_INDEX (item)].word)
 
 /* This is used in lc-CATEGORY.c to define _nl_current_CATEGORY.  */
 #define _NL_CURRENT_DEFINE(category) \
-  extern struct locale_data _nl_C_##category; \
-  struct locale_data *_nl_current_##category = &_nl_C_##category
+  /* No per-category variable here. */
 
 /* Load the locale data for CATEGORY from the file specified by *NAME.
    If *NAME is "", use environment variables as specified by POSIX,

src/system/libroot/posix/glibc/misc/Jamfile

@@ -12,6 +12,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include arch
 			generic ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include ;
+		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ctype ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc libio ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc misc ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc locale ;

src/system/libroot/posix/glibc/stdio-common/Jamfile

@@ -14,6 +14,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			generic ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc stdio-common ;
+		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ctype ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc locale ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ;
 

src/system/libroot/posix/glibc/stdlib/Jamfile

@@ -12,6 +12,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include arch
 			generic ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc include ;
+		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ctype ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc locale ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc stdlib ;
 		SubDirSysHdrs $(HAIKU_TOP) src system libroot posix glibc ;

src/system/libroot/posix/locale/Jamfile

@@ -4,6 +4,7 @@ UsePrivateHeaders
 	[ FDirName libroot ]
 	[ FDirName libroot locale ]
 	[ FDirName libroot time ]
+	[ FDirName system ]
 	;
 
 local architectureObject ;
@@ -12,14 +13,23 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 		local architecture = $(TARGET_PACKAGING_ARCH) ;
 
 		MergeObject <$(architecture)>posix_locale.o :
+			ctype_l.cpp
 			ctype.cpp
 			LocaleBackend.cpp
 			LocaleData.cpp
 			LocaleDataBridge.cpp
+			LocaleInternal.cpp
+			locale_t.cpp
 			localeconv.cpp
 			nl_langinfo.cpp
 			setlocale.cpp
+			ThreadLocale.cpp
+			wctype_l.cpp
 			wctype.cpp
 			;
+
+		MergeObject <$(architecture)>ctype_loc.o :
+			ctype_loc.cpp
+			;
 	}
 }

src/system/libroot/posix/locale/LocaleBackend.cpp

@@ -10,37 +10,56 @@
 #include <pthread.h>
 #include <string.h>
 
+#include <ThreadLocale.h>
+
 
 namespace BPrivate {
 namespace Libroot {
 
 
-LocaleBackend* gLocaleBackend = NULL;
+LocaleBackend* gGlobalLocaleBackend = NULL;
+LocaleDataBridge gGlobalLocaleDataBridge = LocaleDataBridge(true);
+
+
+static void* sImageHandle = NULL;
+typedef LocaleBackend* (*create_instance_t)();
+typedef void (*destroy_instance_t)(LocaleBackend*);
+static create_instance_t sCreateInstanceFunc = NULL;
+static destroy_instance_t sDestroyInstanceFunc = NULL;
 
 
-static LocaleDataBridge sLocaleDataBridge;
 static pthread_once_t sBackendInitOnce = PTHREAD_ONCE_INIT;
+static pthread_once_t sFunctionsInitOnce = PTHREAD_ONCE_INIT;
+
+
+static void
+LoadFunctions()
+{
+	sImageHandle = dlopen("libroot-addon-icu.so", RTLD_LAZY);
+	if (sImageHandle == NULL)
+		return;
+
+	sCreateInstanceFunc = (create_instance_t)dlsym(sImageHandle, "CreateInstance");
+	sDestroyInstanceFunc = (destroy_instance_t)dlsym(sImageHandle, "DestroyInstance");
+
+	if ((sCreateInstanceFunc == NULL) || (sDestroyInstanceFunc == NULL)) {
+		dlclose(sImageHandle);
+		return;
+	}
+}
 
 
 static void
 LoadBackend()
 {
-	void* imageHandle = dlopen("libroot-addon-icu.so", RTLD_LAZY);
-	if (imageHandle == NULL)
-		return;
-
-	typedef LocaleBackend* (*symbolType)();
-	symbolType createInstanceFunc
-		= (symbolType)dlsym(imageHandle, "CreateInstance");
-	if (createInstanceFunc == NULL) {
-		dlclose(imageHandle);
-		return;
+	gGlobalLocaleBackend = LocaleBackend::CreateBackend();
+	if (gGlobalLocaleBackend != NULL) {
+		gGlobalLocaleBackend->Initialize(&gGlobalLocaleDataBridge);
 	}
-
-	gLocaleBackend = createInstanceFunc();
 }
 
 
+
 LocaleBackend::LocaleBackend()
 {
 }
@@ -54,15 +73,60 @@ LocaleBackend::~LocaleBackend()
 status_t
 LocaleBackend::LoadBackend()
 {
-	if (gLocaleBackend == NULL) {
+	if (gGlobalLocaleBackend == NULL) {
 		pthread_once(&sBackendInitOnce, &BPrivate::Libroot::LoadBackend);
-		if (gLocaleBackend != NULL)
-			gLocaleBackend->Initialize(&sLocaleDataBridge);
 	}
 
-	return gLocaleBackend != NULL ? B_OK : B_ERROR;
+	return gGlobalLocaleBackend != NULL ? B_OK : B_ERROR;
 }
 
 
+LocaleBackend*
+LocaleBackend::CreateBackend()
+{
+	if (sCreateInstanceFunc == NULL) {
+		pthread_once(&sFunctionsInitOnce, &BPrivate::Libroot::LoadFunctions);
+	}
+
+	if (sCreateInstanceFunc != NULL) {
+		LocaleBackend* backend = sCreateInstanceFunc();
+		return backend;
+	}
+
+	return NULL;
+}
+
+
+void
+LocaleBackend::DestroyBackend(LocaleBackend* instance)
+{
+	if (sDestroyInstanceFunc != NULL) {
+		sDestroyInstanceFunc(instance);
+	}
+}
+
+
+LocaleBackendData* GetCurrentLocaleInfo()
+{
+	return GetCurrentThreadLocale()->threadLocaleInfo;
+}
+
+
+void
+SetCurrentLocaleInfo(LocaleBackendData* newLocale)
+{
+	GetCurrentThreadLocale()->threadLocaleInfo = newLocale;
+}
+
+
+LocaleBackend* GetCurrentLocaleBackend()
+{
+	LocaleBackendData* info = GetCurrentThreadLocale()->threadLocaleInfo;
+	if (info != NULL && info->backend != NULL) {
+		return info->backend;
+	}
+	return gGlobalLocaleBackend;
+}
+
 }	// namespace Libroot
 }	// namespace BPrivate

src/system/libroot/posix/locale/LocaleDataBridge.cpp

@@ -15,24 +15,45 @@
 #include <PosixLanginfo.h>
 #include <PosixLCTimeInfo.h>
 #include <PosixLocaleConv.h>
+#include <ThreadLocale.h>
 
 
-extern locale_data* _nl_current_LC_NUMERIC;
+extern const unsigned short* __ctype_b;
+extern const int* __ctype_tolower;
+extern const int* __ctype_toupper;
 
 
 namespace BPrivate {
 namespace Libroot {
 
 
-LocaleCtypeDataBridge::LocaleCtypeDataBridge()
+extern "C" GlibcLocaleStruct* _nl_current_locale();
+extern "C" GlibcLocaleStruct _nl_global_locale;
+#define _NL_CURRENT_DATA(category) \
+	((locale_data*&)(_nl_current_locale()->__locales[category]))
+#define _NL_GLOBAL_DATA(category) \
+	((locale_data*&)(_nl_global_locale.__locales[category]))
+
+
+LocaleCtypeDataBridge::LocaleCtypeDataBridge(bool isGlobal)
 	:
-	addrOfClassInfoTable(&__ctype_b),
-	addrOfToLowerTable(&__ctype_tolower),
-	addrOfToUpperTable(&__ctype_toupper),
+	localClassInfoTable(__ctype_b),
+	localToLowerTable(__ctype_tolower),
+	localToUpperTable(__ctype_toupper),
 	posixClassInfo(gPosixClassInfo),
 	posixToLowerMap(gPosixToLowerMap),
-	posixToUpperMap(gPosixToUpperMap)
+	posixToUpperMap(gPosixToUpperMap),
+	isGlobal(isGlobal)
 {
+	if (isGlobal) {
+		addrOfClassInfoTable = &__ctype_b;
+		addrOfToLowerTable = &__ctype_tolower;
+		addrOfToUpperTable = &__ctype_toupper;
+	} else {
+		addrOfClassInfoTable = &localClassInfoTable;
+		addrOfToLowerTable = &localToLowerTable;
+		addrOfToUpperTable = &localToUpperTable;
+	}
 }
 
 
@@ -42,6 +63,15 @@ void LocaleCtypeDataBridge::setMbCurMax(unsigned short mbCurMax)
 }
 
 
+void
+LocaleCtypeDataBridge::ApplyToCurrentThread()
+{
+	*__ctype_b_loc() = *addrOfClassInfoTable;
+	*__ctype_tolower_loc() = *addrOfToLowerTable;
+	*__ctype_toupper_loc() = *addrOfToUpperTable;
+}
+
+
 LocaleMessagesDataBridge::LocaleMessagesDataBridge()
 	:
 	posixLanginfo(gPosixLanginfo)
@@ -56,20 +86,36 @@ LocaleMonetaryDataBridge::LocaleMonetaryDataBridge()
 }
 
 
-LocaleNumericDataBridge::LocaleNumericDataBridge()
+LocaleNumericDataBridge::LocaleNumericDataBridge(bool isGlobal)
 	:
-	originalGlibcLocale(_nl_current_LC_NUMERIC),
-	posixLocaleConv(&gPosixLocaleConv)
+	posixLocaleConv(&gPosixLocaleConv),
+	glibcNumericLocale(&glibcNumericLocaleData)
 {
-	memcpy(&glibcNumericLocale, _nl_current_LC_NUMERIC,
-		sizeof(glibcNumericLocale));
-	_nl_current_LC_NUMERIC = (locale_data*)&glibcNumericLocale;
+
+	memcpy(glibcNumericLocale, _NL_GLOBAL_DATA(GLIBC_LC_NUMERIC),
+		sizeof(GlibcNumericLocale));
+
+	if (isGlobal) {
+		originalGlibcLocale = _NL_GLOBAL_DATA(GLIBC_LC_NUMERIC);
+		_NL_GLOBAL_DATA(GLIBC_LC_NUMERIC) = (locale_data*)glibcNumericLocale;
+	}
 }
 
 
 LocaleNumericDataBridge::~LocaleNumericDataBridge()
 {
-	_nl_current_LC_NUMERIC = originalGlibcLocale;
+	if (isGlobal) {
+		_NL_GLOBAL_DATA(GLIBC_LC_NUMERIC) = originalGlibcLocale;
+	} else if (_NL_CURRENT_DATA(GLIBC_LC_NUMERIC) == (locale_data*)glibcNumericLocale) {
+		_NL_CURRENT_DATA(GLIBC_LC_NUMERIC) = _NL_GLOBAL_DATA(GLIBC_LC_NUMERIC);
+	}
+}
+
+
+void
+LocaleNumericDataBridge::ApplyToCurrentThread()
+{
+	_NL_CURRENT_DATA(GLIBC_LC_NUMERIC) = (locale_data*)glibcNumericLocale;
 }
 
 
@@ -80,19 +126,50 @@ LocaleTimeDataBridge::LocaleTimeDataBridge()
 }
 
 
-TimeConversionDataBridge::TimeConversionDataBridge()
+TimeConversionDataBridge::TimeConversionDataBridge(bool isGlobal)
 	:
-	addrOfDaylight(&daylight),
-	addrOfTimezone(&timezone),
-	addrOfTZName(tzname)
+	localDaylight(daylight),
+	localTimezone(timezone),
+	isGlobal(isGlobal)
+{
+	if (isGlobal) {
+		addrOfDaylight = &daylight;
+		addrOfTimezone = &timezone;
+		addrOfTZName = tzname;
+	} else {
+		addrOfDaylight = &localDaylight;
+		addrOfTimezone = &localTimezone;
+		addrOfTZName = localTZName;
+		addrOfTZName[0] = localTZName0;
+		addrOfTZName[1] = localTZName1;
+		strlcpy(localTZName0, tzname[0], sizeof(localTZName0));
+		strlcpy(localTZName1, tzname[1], sizeof(localTZName1));
+	}
+}
+
+
+LocaleDataBridge::LocaleDataBridge(bool isGlobal)
+	:
+	ctypeDataBridge(isGlobal),
+	numericDataBridge(isGlobal),
+	timeConversionDataBridge(isGlobal),
+	posixLanginfo(gPosixLanginfo),
+	isGlobal(isGlobal)
 {
 }
 
 
-LocaleDataBridge::LocaleDataBridge()
-	:
-	posixLanginfo(gPosixLanginfo)
+void
+LocaleDataBridge::ApplyToCurrentThread()
 {
+	ctypeDataBridge.ApplyToCurrentThread();
+	numericDataBridge.ApplyToCurrentThread();
+	// While timeConverstionDataBridge stores read-write variables,
+	// these variables are global (by POSIX definition). Furthermore,
+	// none of the backends seem to access these variables
+	// directly. The values are set in the bridge mostly for
+	// synchronization purposes. Therefore, don't call
+	// ApplyToCurrentThread for this object.
 }
 
 

src/system/libroot/posix/locale/LocaleInternal.cpp

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2004-2007, Axel Dörfler, axeld@pinc-software.de
+ * Copyright 2010, Oliver Tappe, zooey@hirschkaefer.de
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include "LocaleInternal.h"
+
+#include <locale.h>
+#include <stdlib.h>
+#include <strings.h>
+
+#include <Debug.h>
+
+
+namespace BPrivate {
+namespace Libroot {
+
+
+status_t
+GetLocalesFromEnvironment(int category, const char** locales)
+{
+	if (category > LC_LAST) {
+		return B_BAD_VALUE;
+	}
+
+	const char* locale = getenv("LC_ALL");
+	if (locale != NULL && *locale != '\0')
+		locales[category] = locale;
+	else {
+		// the order of the names must match the one specified in locale.h
+		const char* const categoryNames[] = {
+			"LC_ALL",
+			"LC_COLLATE",
+			"LC_CTYPE",
+			"LC_MONETARY",
+			"LC_NUMERIC",
+			"LC_TIME",
+			"LC_MESSAGES"
+		};
+
+		STATIC_ASSERT(B_COUNT_OF(categoryNames) == LC_LAST + 1);
+
+		int from, to;
+		if (category == LC_ALL) {
+			// we need to check each real category if all of them should be set
+			from = 1;
+			to = LC_LAST;
+		} else
+			from = to = category;
+		bool haveDifferentLocales = false;
+		locale = NULL;
+		for (int lc = from; lc <= to; lc++) {
+			const char* lastLocale = locale;
+			locale = getenv(categoryNames[lc]);
+			if (locale == NULL || *locale == '\0')
+				locale = getenv("LANG");
+			if (locale == NULL || *locale == '\0')
+				locale = "POSIX";
+			locales[lc] = locale;
+			if (lastLocale != NULL && strcasecmp(locale, lastLocale) != 0)
+				haveDifferentLocales = true;
+		}
+		if (!haveDifferentLocales) {
+			// we can set all locales at once
+			locales[LC_ALL] = locale;
+		}
+	}
+
+	return B_OK;
+}
+
+}	// namespace Libroot
+}	// namespace BPrivate

src/system/libroot/posix/locale/LocaleInternal.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2004-2007, Axel Dörfler, axeld@pinc-software.de
+ * Copyright 2010, Oliver Tappe, zooey@hirschkaefer.de
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <SupportDefs.h>
+
+
+#define LOCALE_T_MAGIC 'LOCA'
+
+
+namespace BPrivate {
+namespace Libroot {
+
+
+status_t GetLocalesFromEnvironment(int category, const char** locales);
+
+}	// namespace Libroot
+}	// namespace BPrivate

src/system/libroot/posix/locale/ThreadLocale.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <ctype.h>
+
+#include <tls.h>
+#include <kernel/OS.h>
+#include <ThreadLocale.h>
+
+
+// From glibc's localeinfo.h
+extern BPrivate::Libroot::GlibcLocaleStruct _nl_global_locale;
+
+
+namespace BPrivate {
+namespace Libroot {
+
+
+static void DestroyThreadLocale(void* ptr)
+{
+	ThreadLocale* threadLocale = (ThreadLocale*)ptr;
+	delete threadLocale;
+}
+
+
+ThreadLocale*
+GetCurrentThreadLocale()
+{
+	ThreadLocale* threadLocale = (ThreadLocale*)tls_get(TLS_LOCALE_SLOT);
+	if (threadLocale == NULL) {
+		threadLocale = new ThreadLocale();
+		threadLocale->glibcLocaleStruct = _nl_global_locale;
+		threadLocale->threadLocaleInfo = NULL;
+		on_exit_thread(DestroyThreadLocale, threadLocale);
+		tls_set(TLS_LOCALE_SLOT, threadLocale);
+	}
+	return threadLocale;
+}
+
+
+// Exported so that glibc could also use.
+extern "C" GlibcLocaleStruct*
+_nl_current_locale()
+{
+	return &GetCurrentThreadLocale()->glibcLocaleStruct;
+}
+
+
+extern "C" const unsigned short**
+__ctype_b_loc()
+{
+	return &GetCurrentThreadLocale()->glibcLocaleStruct.__ctype_b;
+}
+
+
+extern "C" const int**
+__ctype_tolower_loc()
+{
+	return &GetCurrentThreadLocale()->glibcLocaleStruct.__ctype_tolower;
+}
+
+
+extern "C" const int**
+__ctype_toupper_loc()
+{
+	return &GetCurrentThreadLocale()->glibcLocaleStruct.__ctype_toupper;
+}
+
+
+}	// namespace Libroot
+}	// namespace BPrivate

src/system/libroot/posix/locale/ctype.cpp

@@ -44,7 +44,7 @@ int
 isalnum(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & (_ISupper | _ISlower | _ISdigit);
+		return (*__ctype_b_loc())[c] & (_ISupper | _ISlower | _ISdigit);
 
 	return 0;
 }
@@ -54,7 +54,7 @@ int
 isalpha(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & (_ISupper | _ISlower);
+		return (*__ctype_b_loc())[c] & (_ISupper | _ISlower);
 
 	return 0;
 }
@@ -72,7 +72,7 @@ int
 isblank(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISblank;
+		return (*__ctype_b_loc())[c] & _ISblank;
 
 	return 0;
 }
@@ -82,7 +82,7 @@ int
 iscntrl(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _IScntrl;
+		return (*__ctype_b_loc())[c] & _IScntrl;
 
 	return 0;
 }
@@ -92,7 +92,7 @@ int
 isdigit(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISdigit;
+		return (*__ctype_b_loc())[c] & _ISdigit;
 
 	return 0;
 }
@@ -102,7 +102,7 @@ int
 isgraph(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISgraph;
+		return (*__ctype_b_loc())[c] & _ISgraph;
 
 	return 0;
 }
@@ -112,7 +112,7 @@ int
 islower(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISlower;
+		return (*__ctype_b_loc())[c] & _ISlower;
 
 	return 0;
 }
@@ -122,7 +122,7 @@ int
 isprint(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISprint;
+		return (*__ctype_b_loc())[c] & _ISprint;
 
 	return 0;
 }
@@ -132,7 +132,7 @@ int
 ispunct(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISpunct;
+		return (*__ctype_b_loc())[c] & _ISpunct;
 
 	return 0;
 }
@@ -142,7 +142,7 @@ int
 isspace(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISspace;
+		return (*__ctype_b_loc())[c] & _ISspace;
 
 	return 0;
 }
@@ -152,7 +152,7 @@ int
 isupper(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISupper;
+		return (*__ctype_b_loc())[c] & _ISupper;
 
 	return 0;
 }
@@ -162,7 +162,7 @@ int
 isxdigit(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_b[c] & _ISxdigit;
+		return (*__ctype_b_loc())[c] & _ISxdigit;
 
 	return 0;
 }
@@ -180,7 +180,7 @@ int
 tolower(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_tolower[c];
+		return (*__ctype_tolower_loc())[c];
 
 	return c;
 }
@@ -190,7 +190,7 @@ int
 toupper(int c)
 {
 	if (c >= -128 && c < 256)
-		return __ctype_toupper[c];
+		return (*__ctype_toupper_loc())[c];
 
 	return c;
 }

src/system/libroot/posix/locale/ctype_l.cpp

@@ -0,0 +1,202 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <ctype.h>
+#include <locale.h>
+
+#include <LocaleBackend.h>
+#include <PosixCtype.h>
+
+
+namespace BPrivate {
+namespace Libroot {
+
+
+// A NULL databridge means that the object represents the POSIX locale.
+static const unsigned short*
+GetClassInfoTable(locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+
+	if (locale->databridge == NULL) {
+		return &gPosixClassInfo[128];
+	}
+	return *locale->databridge->ctypeDataBridge.addrOfClassInfoTable;
+}
+
+
+static const int*
+GetToUpperTable(locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+
+	if (locale->databridge == NULL) {
+		return &gPosixToUpperMap[128];
+	}
+	return *locale->databridge->ctypeDataBridge.addrOfToUpperTable;
+}
+
+
+static const int*
+GetToLowerTable(locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+
+	if (locale->databridge == NULL) {
+		return &gPosixToLowerMap[128];
+	}
+	return *locale->databridge->ctypeDataBridge.addrOfToLowerTable;
+}
+
+
+extern "C" {
+
+
+int
+isalnum_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & (_ISupper | _ISlower | _ISdigit);
+
+	return 0;
+}
+
+
+int
+isalpha_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & (_ISupper | _ISlower);
+
+	return 0;
+}
+
+
+int
+isblank_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISblank;
+
+	return 0;
+}
+
+
+int
+iscntrl_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _IScntrl;
+
+	return 0;
+}
+
+
+int
+isdigit_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISdigit;
+
+	return 0;
+}
+
+
+int
+isgraph_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISgraph;
+
+	return 0;
+}
+
+
+int
+islower_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISlower;
+
+	return 0;
+}
+
+
+int
+isprint_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISprint;
+
+	return 0;
+}
+
+
+int
+ispunct_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISpunct;
+
+	return 0;
+}
+
+
+int
+isspace_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISspace;
+
+	return 0;
+}
+
+
+int
+isupper_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISupper;
+
+	return 0;
+}
+
+
+int
+isxdigit_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetClassInfoTable(l)[c] & _ISxdigit;
+
+	return 0;
+}
+
+
+int
+tolower_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetToLowerTable(l)[c];
+
+	return c;
+}
+
+
+int
+toupper_l(int c, locale_t l)
+{
+	if (c >= -128 && c < 256)
+		return GetToUpperTable(l)[c];
+
+	return c;
+}
+
+
+}
+
+
+}	// namespace Libroot
+}	// namespace BPrivate

src/system/libroot/posix/locale/ctype_loc.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <ctype.h>
+
+
+// These functions are intended for scenarios where we cannot
+// link to the whole libroot and access pthread functions;
+// for example, when we're in the bootloader, kernel or the
+// runtime_loader.
+
+extern "C" const unsigned short**
+__ctype_b_loc()
+{
+	return &__ctype_b;
+}
+
+
+extern "C" const int**
+__ctype_tolower_loc()
+{
+	return &__ctype_tolower;
+}
+
+
+extern "C" const int**
+__ctype_toupper_loc()
+{
+	return &__ctype_toupper;
+}

src/system/libroot/posix/locale/locale_t.cpp

@@ -0,0 +1,238 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <new>
+#include <errno.h>
+#include <locale.h>
+#include <strings.h>
+
+#include <ErrnoMaintainer.h>
+
+#include "LocaleBackend.h"
+#include "LocaleInternal.h"
+
+
+using BPrivate::Libroot::gGlobalLocaleBackend;
+using BPrivate::Libroot::gGlobalLocaleDataBridge;
+using BPrivate::Libroot::GetCurrentLocaleInfo;
+using BPrivate::Libroot::GetLocalesFromEnvironment;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
+using BPrivate::Libroot::LocaleDataBridge;
+
+
+extern "C" locale_t
+duplocale(locale_t l)
+{
+    LocaleBackendData* locObj = (LocaleBackendData*)l;
+
+    LocaleBackendData* newObj = new (std::nothrow) LocaleBackendData;
+    if (newObj == NULL) {
+        errno = ENOMEM;
+        return (locale_t)0;
+    }
+
+    LocaleBackend* backend = (l == LC_GLOBAL_LOCALE) ?
+        gGlobalLocaleBackend : (LocaleBackend*)locObj->backend;
+
+    if (backend == NULL) {
+        newObj->backend = NULL;
+        return (locale_t)newObj;
+    }
+
+    // Check if everything is set to "C" or "POSIX",
+    // and avoid making a backend.
+    const char* localeDescription = backend->SetLocale(LC_ALL, NULL);
+
+    if ((strcasecmp(localeDescription, "POSIX") == 0)
+        || (strcasecmp(localeDescription, "C") == 0)) {
+        newObj->backend = NULL;
+        return (locale_t)newObj;
+    }
+
+    BPrivate::ErrnoMaintainer errnoMaintainer;
+
+    LocaleBackend*& newBackend = newObj->backend;
+    LocaleDataBridge*& newDataBridge = newObj->databridge;
+    newBackend = LocaleBackend::CreateBackend();
+
+    if (newBackend == NULL) {
+        errno = ENOMEM;
+        delete newObj;
+        return (locale_t)0;
+    }
+
+    newDataBridge = new (std::nothrow) LocaleDataBridge(false);
+
+    if (newDataBridge == NULL) {
+        errno = ENOMEM;
+        delete newBackend;
+        delete newObj;
+        return (locale_t)0;
+    }
+
+    newBackend->Initialize(newDataBridge);
+
+    // Skipping LC_ALL. Asking for LC_ALL would force the backend
+    // to query each other value once, anyway.
+    for (int lc = 1; lc <= LC_LAST; ++lc) {
+        newBackend->SetLocale(lc, backend->SetLocale(lc, NULL));
+    }
+
+    return (locale_t)newObj;
+}
+
+
+extern "C" void
+freelocale(locale_t l)
+{
+    LocaleBackendData* locobj = (LocaleBackendData*)l;
+
+    if (locobj->backend) {
+        LocaleBackend::DestroyBackend(locobj->backend);
+        LocaleDataBridge* databridge = locobj->databridge;
+        delete databridge;
+    }
+    delete locobj;
+}
+
+
+extern "C" locale_t
+newlocale(int category_mask, const char* locale, locale_t base)
+{
+	if (((category_mask | LC_ALL_MASK) != LC_ALL_MASK) || (locale == NULL)) {
+		errno = EINVAL;
+		return (locale_t)0;
+	}
+
+	bool newObject = false;
+	LocaleBackendData* localeObject = (LocaleBackendData*)base;
+
+	if (localeObject == NULL) {
+		localeObject = new (std::nothrow) LocaleBackendData;
+		if (localeObject == NULL) {
+			errno = ENOMEM;
+			return (locale_t)0;
+		}
+		localeObject->magic = LOCALE_T_MAGIC;
+		localeObject->backend = NULL;
+		localeObject->databridge = NULL;
+
+		newObject = true;
+	}
+
+	LocaleBackend*& backend = localeObject->backend;
+	LocaleDataBridge*& databridge = localeObject->databridge;
+
+	const char* locales[LC_LAST + 1];
+	for (int lc = 0; lc <= LC_LAST; lc++)
+		locales[lc] = NULL;
+
+	if (*locale == '\0') {
+		if (category_mask == LC_ALL_MASK) {
+			GetLocalesFromEnvironment(LC_ALL, locales);
+		} else {
+			for (int lc = 1; lc <= LC_LAST; ++lc) {
+				if (category_mask & (1 << (lc - 1))) {
+					GetLocalesFromEnvironment(lc, locales);
+				}
+			}
+		}
+	} else {
+		if (category_mask == LC_ALL_MASK) {
+			locales[LC_ALL] = locale;
+		}
+		for (int lc = 1; lc <= LC_LAST; ++lc) {
+			if (category_mask & (1 << (lc - 1))) {
+				locales[lc] = locale;
+			}
+		}
+	}
+
+	if (backend == NULL) {
+		// for any locale other than POSIX/C, we try to activate the ICU
+		// backend
+		bool needBackend = false;
+		for (int lc = 0; lc <= LC_LAST; lc++) {
+			if (locales[lc] != NULL && strcasecmp(locales[lc], "POSIX") != 0
+					&& strcasecmp(locales[lc], "C") != 0) {
+				needBackend = true;
+				break;
+			}
+		}
+		if (needBackend) {
+			backend = LocaleBackend::CreateBackend();
+			if (backend == NULL) {
+				errno = ENOMEM;
+				if (newObject) {
+					delete localeObject;
+				}
+				return (locale_t)0;
+			}
+			databridge = new (std::nothrow) LocaleDataBridge(false);
+			if (databridge == NULL) {
+				errno = ENOMEM;
+				delete backend;
+				if (newObject) {
+					delete localeObject;
+				}
+				return (locale_t)0;
+			}
+			backend->Initialize(databridge);
+		}
+	}
+
+	BPrivate::ErrnoMaintainer errnoMaintainer;
+
+	if (backend != NULL) {
+		for (int lc = 0; lc <= LC_LAST; lc++) {
+			if (locales[lc] != NULL) {
+				locale = backend->SetLocale(lc, locales[lc]);
+				if (lc == LC_ALL) {
+					// skip the rest, LC_ALL overrides
+					break;
+				}
+			}
+		}
+	}
+
+	return (locale_t)localeObject;
+}
+
+
+extern "C" locale_t
+uselocale(locale_t newLoc)
+{
+    locale_t oldLoc = (locale_t)GetCurrentLocaleInfo();
+    if (oldLoc == NULL) {
+        oldLoc = LC_GLOBAL_LOCALE;
+    }
+
+    if (newLoc != (locale_t)0) {
+        // Avoid expensive TLS reads with a local variable.
+        locale_t appliedLoc = oldLoc;
+
+        if (newLoc == LC_GLOBAL_LOCALE) {
+            appliedLoc = NULL;
+        } else {
+            if (((LocaleBackendData*)newLoc)->magic != LOCALE_T_MAGIC) {
+                errno = EINVAL;
+                return (locale_t)0;
+            }
+            appliedLoc = newLoc;
+        }
+
+        SetCurrentLocaleInfo((LocaleBackendData*)appliedLoc);
+
+        if (appliedLoc != NULL) {
+            ((LocaleBackendData*)appliedLoc)->databridge->ApplyToCurrentThread();
+        } else {
+            gGlobalLocaleDataBridge.ApplyToCurrentThread();
+        }
+    }
+
+    return oldLoc;
+}

src/system/libroot/posix/locale/localeconv.cpp

@@ -11,8 +11,12 @@
 #include <PosixLocaleConv.h>
 
 #ifndef _KERNEL_MODE
+#include <locale.h>
 #include "LocaleBackend.h"
-using BPrivate::Libroot::gLocaleBackend;
+
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 #endif
 
 
@@ -20,9 +24,25 @@ extern "C" struct lconv*
 localeconv(void)
 {
 #ifndef _KERNEL_MODE
-	if (gLocaleBackend)
-		return const_cast<lconv*>(gLocaleBackend->LocaleConv());
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+	if (backend != NULL)
+		return const_cast<lconv*>(backend->LocaleConv());
 #endif
 
 	return &BPrivate::Libroot::gPosixLocaleConv;
 }
+
+
+#ifndef _KERNEL_MODE
+extern "C" struct lconv*
+localeconv_l(locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL)
+		return const_cast<lconv*>(backend->LocaleConv());
+
+	return &BPrivate::Libroot::gPosixLocaleConv;
+}
+#endif

src/system/libroot/posix/locale/nl_langinfo.cpp

@@ -11,8 +11,10 @@
 #include <PosixLanginfo.h>
 
 
-using BPrivate::Libroot::gLocaleBackend;
 using BPrivate::Libroot::gPosixLanginfo;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" char*
@@ -21,8 +23,23 @@ nl_langinfo(nl_item item)
 	if (item < 0 || item >= _NL_LANGINFO_LAST)
 		return const_cast<char*>("");
 
-	if (gLocaleBackend != NULL)
-		return const_cast<char*>(gLocaleBackend->GetLanginfo(item));
+	if (GetCurrentLocaleBackend() != NULL)
+		return const_cast<char*>(GetCurrentLocaleBackend()->GetLanginfo(item));
+
+	return const_cast<char*>(gPosixLanginfo[item]);
+}
+
+
+extern "C" char*
+nl_langinfo_l(nl_item item, locale_t locale)
+{
+	if (item < 0 || item >= _NL_LANGINFO_LAST)
+		return const_cast<char*>("");
+
+	LocaleBackend* backend = ((LocaleBackendData*)locale)->backend;
+
+	if (backend != NULL)
+		return const_cast<char*>(backend->GetLanginfo(item));
 
 	return const_cast<char*>(gPosixLanginfo[item]);
 }

src/system/libroot/posix/locale/setlocale.cpp

@@ -7,65 +7,19 @@
 
 #include <ctype.h>
 #include <locale.h>
-#include <stdlib.h>
 #include <strings.h>
 
 #include <ErrnoMaintainer.h>
 
 #include "LocaleBackend.h"
+#include "LocaleInternal.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::gGlobalLocaleBackend;
+using BPrivate::Libroot::GetLocalesFromEnvironment;
 using BPrivate::Libroot::LocaleBackend;
 
 
-static status_t
-GetLocalesFromEnvironment(int category, const char** locales)
-{
-	const char* locale = getenv("LC_ALL");
-	if (locale && *locale)
-		locales[category] = locale;
-	else {
-		// the order of the names must match the one specified in locale.h
-		const char* categoryNames[] = {
-			"LC_ALL",
-			"LC_COLLATE",
-			"LC_CTYPE",
-			"LC_MONETARY",
-			"LC_NUMERIC",
-			"LC_TIME",
-			"LC_MESSAGES"
-		};
-		int from, to;
-		if (category == LC_ALL) {
-			// we need to check each real category if all of them should be set
-			from = 1;
-			to = LC_LAST;
-		} else
-			from = to = category;
-		bool haveDifferentLocales = false;
-		locale = NULL;
-		for (int lc = from; lc <= to; lc++) {
-			const char* lastLocale = locale;
-			locale = getenv(categoryNames[lc]);
-			if (!locale || *locale == '\0')
-				locale = getenv("LANG");
-			if (!locale || *locale == '\0')
-				locale = "POSIX";
-			locales[lc] = locale;
-			if (lastLocale && strcasecmp(locale, lastLocale) != 0)
-				haveDifferentLocales = true;
-		}
-		if (!haveDifferentLocales) {
-			// we can set all locales at once
-			locales[LC_ALL] = locale;
-		}
-	}
-
-	return B_OK;
-}
-
-
 extern "C" char*
 setlocale(int category, const char* locale)
 {
@@ -76,8 +30,8 @@ setlocale(int category, const char* locale)
 
 	if (locale == NULL) {
 		// query the locale of the given category
-		if (gLocaleBackend != NULL)
-			return const_cast<char*>(gLocaleBackend->SetLocale(category, NULL));
+		if (gGlobalLocaleBackend != NULL)
+			return const_cast<char*>(gGlobalLocaleBackend->SetLocale(category, NULL));
 		else
 			return const_cast<char*>("POSIX");
 	}
@@ -93,7 +47,7 @@ setlocale(int category, const char* locale)
 	else
 		locales[category] = locale;
 
-	if (!gLocaleBackend) {
+	if (gGlobalLocaleBackend == NULL) {
 		// for any locale other than POSIX/C, we try to activate the ICU
 		// backend
 		bool needBackend = false;
@@ -108,17 +62,17 @@ setlocale(int category, const char* locale)
 			return NULL;
 	}
 
-	if (gLocaleBackend != NULL) {
+	if (gGlobalLocaleBackend != NULL) {
 		for (int lc = 0; lc <= LC_LAST; lc++) {
 			if (locales[lc] != NULL) {
-				locale = gLocaleBackend->SetLocale(lc, locales[lc]);
+				locale = gGlobalLocaleBackend->SetLocale(lc, locales[lc]);
 				if (lc == LC_ALL) {
 					// skip the rest, LC_ALL overrides
 					return const_cast<char*>(locale);
 				}
 			}
 		}
-		return const_cast<char*>(gLocaleBackend->SetLocale(category, NULL));
+		return const_cast<char*>(gGlobalLocaleBackend->SetLocale(category, NULL));
 	}
 
 	return const_cast<char*>("POSIX");

src/system/libroot/posix/locale/wctype.cpp

@@ -13,7 +13,9 @@
 #include "LocaleBackend.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+
 
 /*
  * In many of the following functions, we make use of the fact that with
@@ -26,13 +28,15 @@ using BPrivate::Libroot::gLocaleBackend;
 int
 iswctype(wint_t wc, wctype_t charClass)
 {
-	if (gLocaleBackend == NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend == NULL) {
 		if (wc < 0 || wc > 127)
 			return 0;
 		return __isctype(wc, charClass);
 	}
 
-	return gLocaleBackend->IsWCType(wc, charClass);
+	return backend->IsWCType(wc, charClass);
 }
 
 
@@ -123,14 +127,16 @@ iswxdigit(wint_t wc)
 wint_t
 towlower(wint_t wc)
 {
-	if (gLocaleBackend == NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend == NULL) {
 		if (wc < 0 || wc > 127)
 			return wc;
 		return tolower(wc);
 	}
 
 	wint_t result = wc;
-	gLocaleBackend->ToWCTrans(wc, _ISlower, result);
+	backend->ToWCTrans(wc, _ISlower, result);
 
 	return result;
 }
@@ -139,14 +145,16 @@ towlower(wint_t wc)
 wint_t
 towupper(wint_t wc)
 {
-	if (gLocaleBackend == NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend == NULL) {
 		if (wc < 0 || wc > 127)
 			return wc;
 		return toupper(wc);
 	}
 
 	wint_t result = wc;
-	gLocaleBackend->ToWCTrans(wc, _ISupper, result);
+	backend->ToWCTrans(wc, _ISupper, result);
 
 	return result;
 }
@@ -155,7 +163,9 @@ towupper(wint_t wc)
 wint_t
 towctrans(wint_t wc, wctrans_t transition)
 {
-	if (gLocaleBackend == NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend == NULL) {
 		if (transition == _ISlower)
 			return tolower(wc);
 		if (transition == _ISupper)
@@ -166,7 +176,7 @@ towctrans(wint_t wc, wctrans_t transition)
 	}
 
 	wint_t result = wc;
-	status_t status = gLocaleBackend->ToWCTrans(wc, transition, result);
+	status_t status = backend->ToWCTrans(wc, transition, result);
 	if (status != B_OK)
 		__set_errno(EINVAL);
 

src/system/libroot/posix/locale/wctype_l.cpp

@@ -0,0 +1,236 @@
+/*
+ * Copyright 2022, Trung Nguyen, trungnt282910@gmail.com
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+
+#include <ctype.h>
+#include <errno.h>
+#include <locale.h>
+#include <string.h>
+#include <wctype.h>
+
+#include <errno_private.h>
+
+#include "LocaleBackend.h"
+
+
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
+
+
+int
+iswctype_l(wint_t wc, wctype_t charClass, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend == NULL) {
+		if (wc < 0 || wc > 127)
+			return 0;
+		return __isctype(wc, charClass);
+	}
+
+	return backend->IsWCType(wc, charClass);
+}
+
+
+int
+iswalnum_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISalnum, locale);
+}
+
+
+int
+iswalpha_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISalpha, locale);
+}
+
+
+int
+iswblank_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISblank, locale);
+}
+
+
+int
+iswcntrl_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _IScntrl, locale);
+}
+
+
+int
+iswdigit_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISdigit, locale);
+}
+
+
+int
+iswgraph_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISgraph, locale);
+}
+
+
+int
+iswlower_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISlower, locale);
+}
+
+
+int
+iswprint_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISprint, locale);
+}
+
+
+int
+iswpunct_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISpunct, locale);
+}
+
+
+int
+iswspace_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISspace, locale);
+}
+
+
+int
+iswupper_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISupper, locale);
+}
+
+
+int
+iswxdigit_l(wint_t wc, locale_t locale)
+{
+	return iswctype_l(wc, _ISxdigit, locale);
+}
+
+
+wint_t
+towlower_l(wint_t wc, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend == NULL) {
+		if (wc < 0 || wc > 127)
+			return wc;
+		return tolower(wc);
+	}
+
+	wint_t result = wc;
+	backend->ToWCTrans(wc, _ISlower, result);
+
+	return result;
+}
+
+
+wint_t
+towupper_l(wint_t wc, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend == NULL) {
+		if (wc < 0 || wc > 127)
+			return wc;
+		return toupper(wc);
+	}
+
+	wint_t result = wc;
+	backend->ToWCTrans(wc, _ISupper, result);
+
+	return result;
+}
+
+
+wint_t
+towctrans_l(wint_t wc, wctrans_t transition, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend == NULL) {
+		if (transition == _ISlower)
+			return tolower(wc);
+		if (transition == _ISupper)
+			return toupper(wc);
+
+		__set_errno(EINVAL);
+		return wc;
+	}
+
+	wint_t result = wc;
+	status_t status = backend->ToWCTrans(wc, transition, result);
+	if (status != B_OK)
+		__set_errno(EINVAL);
+
+	return result;
+}
+
+
+wctrans_t
+wctrans_l(const char *charClass, locale_t locale)
+{
+	(void)locale;
+
+	if (charClass != NULL) {
+		// we do not know any locale-specific character classes
+		if (strcmp(charClass, "tolower") == 0)
+			return _ISlower;
+		if (strcmp(charClass, "toupper") == 0)
+			return _ISupper;
+	}
+
+	__set_errno(EINVAL);
+	return 0;
+}
+
+
+wctype_t
+wctype_l(const char *property, locale_t locale)
+{
+	(void)locale;
+
+	// currently, we do not support any locale-specific properties
+	if (strcmp(property, "alnum") == 0)
+		return _ISalnum;
+	if (strcmp(property, "alpha") == 0)
+		return _ISalpha;
+	if (strcmp(property, "blank") == 0)
+		return _ISblank;
+	if (strcmp(property, "cntrl") == 0)
+		return _IScntrl;
+	if (strcmp(property, "digit") == 0)
+		return _ISdigit;
+	if (strcmp(property, "graph") == 0)
+		return _ISgraph;
+	if (strcmp(property, "lower") == 0)
+		return _ISlower;
+	if (strcmp(property, "print") == 0)
+		return _ISprint;
+	if (strcmp(property, "punct") == 0)
+		return _ISpunct;
+	if (strcmp(property, "space") == 0)
+		return _ISspace;
+	if (strcmp(property, "upper") == 0)
+		return _ISupper;
+	if (strcmp(property, "xdigit") == 0)
+		return _ISxdigit;
+
+	return 0;
+}

src/system/libroot/posix/stdlib/strfmon.c

@@ -89,19 +89,39 @@
 } while (0)
 
 
-static void __setup_vars(int, char *, char *, char *, char **);
-static int __calc_left_pad(int, char *);
-static char *__format_grouped_double(double, int *, int, int, int);
+extern struct lconv* localeconv_l(locale_t);
+
+static ssize_t __strfmon(char*, size_t, struct lconv*, const char*, va_list ap);
+static void __setup_vars(int, struct lconv*, char *, char *, char *, char **);
+static int __calc_left_pad(int, struct lconv*, char *);
+static char *__format_grouped_double(double, struct lconv*, int *, int, int, int);
 
 
 ssize_t
-strfmon(char *s, size_t maxsize, const char *format,
-    ...)
+strfmon(char *s, size_t maxsize, const char *format, ...)
+{
+	va_list ap;
+	struct lconv* lc = localeconv();
+	va_start(ap, format);
+	return __strfmon(s, maxsize, lc, format, ap);
+}
+
+
+ssize_t
+strfmon_l(char *s, size_t maxsize, locale_t locale, const char *format, ...)
+{
+	va_list ap;
+	struct lconv* lc = localeconv_l(locale);
+	va_start(ap, format);
+	return __strfmon(s, maxsize, lc, format, ap);
+}
+
+
+static ssize_t
+__strfmon(char *s, size_t maxsize, struct lconv* lc, const char *format, va_list ap)
 {
-	va_list			ap;
 	char 			*dst;		/* output destination pointer */
 	const char 		*fmt;		/* current format poistion pointer */
-	struct lconv 	*lc;		/* pointer to lconv structure */
 	char			*asciivalue;	/* formatted double pointer */
 
 	int		flags;		/* formatting options */
@@ -122,9 +142,6 @@ strfmon(char *s, size_t maxsize, const char *format,
 	char	*tmpptr;	/* temporary vars */
 	int		sverrno;
 
-	va_start(ap, format);
-
-	lc = localeconv();
 	dst = s;
 	fmt = format;
 	asciivalue = NULL;
@@ -253,22 +270,22 @@ strfmon(char *s, size_t maxsize, const char *format,
 
 		/* fill left_prec with amount of padding chars */
 		if (left_prec >= 0) {
-			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
-				currency_symbol) - __calc_left_pad(flags, currency_symbol);
+			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE), lc,
+				currency_symbol) - __calc_left_pad(flags, lc, currency_symbol);
 			if (pad_size < 0)
 				pad_size = 0;
 		}
 
 		if (asciivalue != NULL)
 			free(asciivalue);
-		asciivalue = __format_grouped_double(value, &flags, left_prec,
+		asciivalue = __format_grouped_double(value, lc, &flags, left_prec,
 			right_prec, pad_char);
 		if (asciivalue == NULL)
 			goto end_error;		/* errno already set     */
 								/* to ENOMEM by malloc() */
 
 		/* set some variables for later use */
-		__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
+		__setup_vars(flags, lc, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
 
 		/*
 		 * Description of some LC_MONETARY's values:
@@ -405,11 +422,9 @@ end_error:
 
 
 static void
-__setup_vars(int flags, char *cs_precedes, char *sep_by_space, char *sign_posn,
+__setup_vars(int flags, struct lconv* lc, char *cs_precedes, char *sep_by_space, char *sign_posn,
 	char **signstr)
 {
-	struct lconv *lc = localeconv();
-
 	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
 		*cs_precedes = lc->int_n_cs_precedes;
 		*sep_by_space = lc->int_n_sep_by_space;
@@ -443,12 +458,12 @@ __setup_vars(int flags, char *cs_precedes, char *sep_by_space, char *sign_posn,
 
 
 static int
-__calc_left_pad(int flags, char *cur_symb)
+__calc_left_pad(int flags, struct lconv* lc, char *cur_symb)
 {
 	char cs_precedes, sep_by_space, sign_posn, *signstr;
 	int left_chars = 0;
 
-	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
+	__setup_vars(flags, lc, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
 
 	if (cs_precedes != 0) {
 		left_chars += strlen(cur_symb);
@@ -495,7 +510,7 @@ get_groups(int size, char *grouping)
 
 /* convert double to ASCII */
 static char *
-__format_grouped_double(double value, int *flags, int left_prec, int right_prec,
+__format_grouped_double(double value, struct lconv* lc, int *flags, int left_prec, int right_prec,
 	int pad_char)
 {
 	char	*rslt;
@@ -508,7 +523,6 @@ __format_grouped_double(double value, int *flags, int left_prec, int right_prec,
 
 	int		padded;
 
-	struct lconv	*lc = localeconv();
 	char	*grouping;
 	char	decimal_point;
 	char	thousands_sep;

src/system/libroot/posix/string/strcasecmp.c

@@ -68,3 +68,35 @@ strncasecmp(const char *s1, const char *s2, size_t n)
 	return 0;
 }
 
+
+int
+strcasecmp_l(const char *s1, const char *s2, locale_t locale)
+{
+	const u_char *us1 = (const u_char *)s1;
+	const u_char *us2 = (const u_char *)s2;
+
+	while (tolower_l(*us1, locale) == tolower_l(*us2++, locale)) {
+		if (*us1++ == '\0')
+			return 0;
+	}
+
+	return tolower_l(*us1, locale) - tolower_l(*--us2, locale);
+}
+
+
+int
+strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t locale)
+{
+	if (n != 0) {
+		const u_char *us1 = (const u_char *)s1;
+		const u_char *us2 = (const u_char *)s2;
+
+		do {
+			if (tolower_l(*us1, locale) != tolower_l(*us2++, locale))
+				return tolower_l(*us1, locale) - tolower_l(*--us2, locale);
+			if (*us1++ == '\0')
+				break;
+		} while (--n != 0);
+	}
+	return 0;
+}

src/system/libroot/posix/string/strcoll.cpp

@@ -11,15 +11,39 @@
 #include "LocaleBackend.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" int
 strcoll(const char *a, const char *b)
 {
-	if (gLocaleBackend != NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		int result = 0;
-		status_t status = gLocaleBackend->Strcoll(a, b, result);
+		status_t status = backend->Strcoll(a, b, result);
+
+		if (status != B_OK)
+			__set_errno(EINVAL);
+
+		return result;
+	}
+
+	return strcmp(a, b);
+}
+
+
+extern "C" int
+strcoll_l(const char *a, const char *b, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL) {
+		int result = 0;
+		status_t status = backend->Strcoll(a, b, result);
 
 		if (status != B_OK)
 			__set_errno(EINVAL);

src/system/libroot/posix/string/strerror.c

@@ -583,3 +583,11 @@ strerror_r(int error, char *buffer, size_t bufferSize)
 		// TODO: could return ERANGE if buffer is too small
 }
 
+
+char *
+strerror_l(int error, locale_t locale)
+{
+	// Don't have error messages in other locales yet.
+	(void)locale;
+	return strerror(error);
+}

src/system/libroot/posix/string/strxfrm.cpp

@@ -11,15 +11,39 @@
 #include "LocaleBackend.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" size_t
 strxfrm(char *out, const char *in, size_t size)
 {
-	if (gLocaleBackend != NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		size_t outSize = 0;
-		status_t status =  gLocaleBackend->Strxfrm(out, in, size, outSize);
+		status_t status = backend->Strxfrm(out, in, size, outSize);
+
+		if (status != B_OK)
+			__set_errno(EINVAL);
+
+		return outSize;
+	}
+
+	return strlcpy(out, in, size);
+}
+
+
+extern "C" size_t
+strxfrm_l(char *out, const char *in, size_t size, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL) {
+		size_t outSize = 0;
+		status_t status = backend->Strxfrm(out, in, size, outSize);
 
 		if (status != B_OK)
 			__set_errno(EINVAL);

src/system/libroot/posix/time/localtime.cpp

@@ -17,7 +17,7 @@
 #include "LocaleBackend.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
 using BPrivate::Libroot::LocaleBackend;
 
 
@@ -43,13 +43,13 @@ extern "C" time_t __timegm_fallback(struct tm* tmp);
 extern "C" void
 tzset(void)
 {
-	if (gLocaleBackend == NULL && LocaleBackend::LoadBackend() != B_OK)
+	if (GetCurrentLocaleBackend() == NULL && LocaleBackend::LoadBackend() != B_OK)
 		return;
 
 	char timeZoneID[B_FILE_NAME_LENGTH] = { "GMT" };
 	_kern_get_timezone(NULL, timeZoneID, sizeof(timeZoneID));
 
-	gLocaleBackend->TZSet(timeZoneID, getenv("TZ"));
+	GetCurrentLocaleBackend()->TZSet(timeZoneID, getenv("TZ"));
 }
 
 
@@ -71,8 +71,11 @@ localtime_r(const time_t* inTime, struct tm* tmOut)
 	}
 
 	tzset();
-	if (gLocaleBackend != NULL) {
-		status_t status = gLocaleBackend->Localtime(inTime, tmOut);
+
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
+		status_t status = backend->Localtime(inTime, tmOut);
 
 		if (status != B_OK)
 			__set_errno(EOVERFLOW);
@@ -104,8 +107,11 @@ gmtime_r(const time_t* inTime, struct tm* tmOut)
 	}
 
 	tzset();
-	if (gLocaleBackend != NULL) {
-		status_t status = gLocaleBackend->Gmtime(inTime, tmOut);
+
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
+		status_t status = backend->Gmtime(inTime, tmOut);
 
 		if (status != B_OK)
 			__set_errno(EOVERFLOW);
@@ -128,9 +134,12 @@ mktime(struct tm* inTm)
 	}
 
 	tzset();
-	if (gLocaleBackend != NULL) {
+
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		time_t timeOut;
-		status_t status = gLocaleBackend->Mktime(inTm, timeOut);
+		status_t status = backend->Mktime(inTm, timeOut);
 
 		if (status != B_OK) {
 			__set_errno(EOVERFLOW);
@@ -154,9 +163,12 @@ timegm(struct tm* inTm)
 		return -1;
 	}
 	tzset();
-	if (gLocaleBackend != NULL) {
+
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		time_t timeOut;
-		status_t status = gLocaleBackend->Timegm(inTm, timeOut);
+		status_t status = backend->Timegm(inTm, timeOut);
 
 		if (status != B_OK) {
 			__set_errno(EOVERFLOW);

src/system/libroot/posix/time/strftime.c

@@ -38,13 +38,13 @@ static const char	sccsid[] = "@(#)strftime.c	5.4 (Berkeley) 3/14/89";
 #include "locale.h"
 #include "timelocal.h"
 
-#define Locale __get_current_time_locale()
-
 static char *	_add P((const char *, char *, const char *));
 static char *	_conv P((int, const char *, char *, const char *));
 static char *	_fmt P((const char *, const struct tm *, char *, const char *,
-			int *));
+			int *, const struct lc_time_t*));
 static char *	_yconv P((int, int, int, int, char *, const char *));
+static size_t __strftime(char * const, const size_t, const char * const,
+	const struct tm * const, const struct lc_time_t*);
 
 extern char *	tzname[];
 
@@ -60,18 +60,32 @@ extern char *	tzname[];
 #define NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
 
 size_t
-strftime(s, maxsize, format, t)
+strftime(char* const s, const size_t maxsize, const char* const format, const struct tm* const t)
+{
+	return __strftime(s, maxsize, format, t, __get_current_time_locale());
+}
+
+size_t
+strftime_l(char* const s, const size_t maxsize, const char* const format, const struct tm* const t,
+	locale_t locale)
+{
+	return __strftime(s, maxsize, format, t, __get_time_locale(locale));
+}
+
+static size_t
+__strftime(s, maxsize, format, t, locale)
 char * const		s;
 const size_t		maxsize;
 const char * const	format;
 const struct tm * const	t;
+const struct lc_time_t* locale;
 {
 	char *	p;
 	int	warn;
 
 	tzset();
 	warn = IN_NONE;
-	p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn);
+	p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, locale);
 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
 	if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
 		(void) fprintf(stderr, "\n");
@@ -95,12 +109,13 @@ const struct tm * const	t;
 }
 
 static char *
-_fmt(format, t, pt, ptlim, warnp)
+_fmt(format, t, pt, ptlim, warnp, Locale)
 const char *		format;
 const struct tm * const	t;
 char *			pt;
 const char * const	ptlim;
 int *			warnp;
+const struct lc_time_t* Locale;
 {
 	for ( ; *format; ++format) {
 		if (*format == '%') {
@@ -152,13 +167,13 @@ label:
 				{
 				int warn2 = IN_SOME;
 
-				pt = _fmt(Locale->c_fmt, t, pt, ptlim, warnp);
+				pt = _fmt(Locale->c_fmt, t, pt, ptlim, warnp, Locale);
 				if (warn2 > *warnp)
 					*warnp = warn2;
 				}
 				continue;
 			case 'D':
-				pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
+				pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'd':
 				pt = _conv(t->tm_mday, "%02d", pt, ptlim);
@@ -179,7 +194,7 @@ label:
 				pt = _conv(t->tm_mday, "%2d", pt, ptlim);
 				continue;
 			case 'F':
-				pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
+				pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'H':
 				pt = _conv(t->tm_hour, "%02d", pt, ptlim);
@@ -243,10 +258,10 @@ label:
 					pt, ptlim);
 				continue;
 			case 'R':
-				pt = _fmt("%H:%M", t, pt, ptlim, warnp);
+				pt = _fmt("%H:%M", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'r':
-				pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
+				pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'S':
 				pt = _conv(t->tm_sec, "%02d", pt, ptlim);
@@ -269,7 +284,7 @@ label:
 				}
 				continue;
 			case 'T':
-				pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
+				pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 't':
 				pt = _add("\t", pt, ptlim);
@@ -384,7 +399,7 @@ label:
 				** "date as dd-bbb-YYYY"
 				** (ado, 1993-05-24)
 				*/
-				pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
+				pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'W':
 				pt = _conv((t->tm_yday + DAYSPERWEEK -
@@ -397,13 +412,13 @@ label:
 				pt = _conv(t->tm_wday, "%d", pt, ptlim);
 				continue;
 			case 'X':
-				pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
+				pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp, Locale);
 				continue;
 			case 'x':
 				{
 				int	warn2 = IN_SOME;
 
-				pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
+				pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2, Locale);
 				if (warn2 == IN_ALL)
 					warn2 = IN_THIS;
 				if (warn2 > *warnp)
@@ -489,7 +504,7 @@ label:
 				continue;
 			case '+':
 				pt = _fmt(Locale->date_fmt, t, pt, ptlim,
-					warnp);
+					warnp, Locale);
 				continue;
 			case '%':
 			/*

src/system/libroot/posix/time/timelocal.cpp

@@ -12,14 +12,29 @@
 #include "PosixLCTimeInfo.h"
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" const lc_time_t*
 __get_current_time_locale(void)
 {
-	if (gLocaleBackend)
-		return gLocaleBackend->LCTimeInfo();
+	if (GetCurrentLocaleBackend() != NULL)
+		return GetCurrentLocaleBackend()->LCTimeInfo();
+
+	return &BPrivate::Libroot::gPosixLCTimeInfo;
+}
+
+
+extern "C" const lc_time_t*
+__get_time_locale(locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL)
+		return backend->LCTimeInfo();
 
 	return &BPrivate::Libroot::gPosixLCTimeInfo;
 }

src/system/libroot/posix/wchar/mbrtowc.cpp

@@ -20,7 +20,8 @@
 #endif
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
 
 
 extern "C" size_t
@@ -34,7 +35,9 @@ __mbrtowc(wchar_t* pwc, const char* s, size_t n, mbstate_t* ps)
 	if (s == NULL)
 		return __mbrtowc(NULL, "", 1, ps);
 
-	if (gLocaleBackend == NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend == NULL) {
 		if (*s == '\0') {
 			memset(ps, 0, sizeof(mbstate_t));
 
@@ -63,8 +66,7 @@ __mbrtowc(wchar_t* pwc, const char* s, size_t n, mbstate_t* ps)
 	}
 
 	size_t lengthUsed;
-	status_t status
-		= gLocaleBackend->MultibyteToWchar(pwc, s, n, ps, lengthUsed);
+	status_t status = backend->MultibyteToWchar(pwc, s, n, ps, lengthUsed);
 
 	if (status == B_BAD_INDEX)
 		return (size_t)-2;

src/system/libroot/posix/wchar/mbsrtowcs.cpp

@@ -20,22 +20,25 @@
 #endif
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
 
 
 extern "C" size_t
 __mbsnrtowcs(wchar_t* dst, const char** src, size_t nmc, size_t len,
 	mbstate_t* ps)
 {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
 	TRACE(("mbsnrtowcs(%p, %p, %lu, %lu) - lb:%p\n", dst, *src, nmc, len,
-		gLocaleBackend));
+		backend));
 
 	if (ps == NULL) {
 		static mbstate_t internalMbState;
 		ps = &internalMbState;
 	}
 
-	if (gLocaleBackend == NULL) {
+	if (backend == NULL) {
 		/*
 		 * The POSIX locale is active. Since the POSIX locale only contains
 		 * chars 0-127 and those ASCII chars are compatible with the UTF32
@@ -82,7 +85,7 @@ __mbsnrtowcs(wchar_t* dst, const char** src, size_t nmc, size_t len,
 	}
 
 	size_t result = 0;
-	status_t status = gLocaleBackend->MultibyteStringToWchar(dst, len, src, nmc,
+	status_t status = backend->MultibyteStringToWchar(dst, len, src, nmc,
 		ps, result);
 
 	if (status == B_BAD_DATA) {
@@ -112,7 +115,8 @@ __mbsrtowcs(wchar_t* dst, const char** src, size_t len, mbstate_t* ps)
 		ps = &internalMbState;
 	}
 
-	size_t srcLen = gLocaleBackend == NULL ? strlen(*src) + 1 : (size_t)-1;
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+	size_t srcLen = backend == NULL ? strlen(*src) + 1 : (size_t)-1;
 
 	return __mbsnrtowcs(dst, src, srcLen, len, ps);
 }

src/system/libroot/posix/wchar/wcrtomb.cpp

@@ -20,12 +20,15 @@
 #endif
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
 
 
 extern "C" size_t
 __wcrtomb(char* s, wchar_t wc, mbstate_t* ps)
 {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
 	if (ps == NULL) {
 		static mbstate_t internalMbState;
 		ps = &internalMbState;
@@ -34,7 +37,7 @@ __wcrtomb(char* s, wchar_t wc, mbstate_t* ps)
 	if (s == NULL)
 		wc = 0;
 
-	if (gLocaleBackend == NULL) {
+	if (backend == NULL) {
 		/*
 		 * The POSIX locale is active. Since the POSIX locale only contains
 		 * chars 0-127 and those ASCII chars are compatible with the UTF32
@@ -54,7 +57,7 @@ __wcrtomb(char* s, wchar_t wc, mbstate_t* ps)
 	}
 
 	size_t lengthUsed;
-	status_t status = gLocaleBackend->WcharToMultibyte(s, wc, ps, lengthUsed);
+	status_t status = backend->WcharToMultibyte(s, wc, ps, lengthUsed);
 
 	if (status == B_BAD_INDEX)
 		return (size_t)-2;

src/system/libroot/posix/wchar/wcscasecmp.c

@@ -27,3 +27,22 @@ __wcscasecmp(const wchar_t* wcs1, const wchar_t* wcs2)
 
 
 B_DEFINE_WEAK_ALIAS(__wcscasecmp, wcscasecmp);
+
+
+int
+__wcscasecmp_l(const wchar_t* wcs1, const wchar_t* wcs2, locale_t locale)
+{
+	int cmp;
+
+	for (;;) {
+		cmp = towlower_l(*wcs1, locale) - towlower_l(*wcs2++, locale);
+
+		if (cmp != 0 || *wcs1++ == L'\0')
+			break;
+	}
+
+	return cmp;
+}
+
+
+B_DEFINE_WEAK_ALIAS(__wcscasecmp_l, wcscasecmp_l);

src/system/libroot/posix/wchar/wcscoll.cpp

@@ -8,15 +8,19 @@
 #include <wchar_private.h>
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" int
 __wcscoll(const wchar_t* wcs1, const wchar_t* wcs2)
 {
-	if (gLocaleBackend != NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		int result = 0;
-		status_t status = gLocaleBackend->Wcscoll(wcs1, wcs2, result);
+		status_t status = backend->Wcscoll(wcs1, wcs2, result);
 
 		if (status != B_OK)
 			__set_errno(EINVAL);
@@ -29,3 +33,26 @@ __wcscoll(const wchar_t* wcs1, const wchar_t* wcs2)
 
 
 B_DEFINE_WEAK_ALIAS(__wcscoll, wcscoll);
+
+
+extern "C" int
+__wcscoll_l(const wchar_t* wcs1, const wchar_t* wcs2, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL) {
+		int result = 0;
+		status_t status = backend->Wcscoll(wcs1, wcs2, result);
+
+		if (status != B_OK)
+			__set_errno(EINVAL);
+
+		return result;
+	}
+
+	return wcscmp(wcs1, wcs2);
+}
+
+
+B_DEFINE_WEAK_ALIAS(__wcscoll_l, wcscoll_l);

src/system/libroot/posix/wchar/wcsncasecmp.c

@@ -27,3 +27,24 @@ __wcsncasecmp(const wchar_t* wcs1, const wchar_t* wcs2, size_t count)
 
 
 B_DEFINE_WEAK_ALIAS(__wcsncasecmp, wcsncasecmp);
+
+
+int
+__wcsncasecmp_l(const wchar_t* wcs1, const wchar_t* wcs2, size_t count, locale_t locale)
+{
+	int cmp = 0;
+
+	while (count-- > 0) {
+		cmp = towlower_l(*wcs1, locale) - towlower_l(*wcs2++, locale);
+			/* note: won't overflow, since our wchar_t is guaranteed to never
+			   have the highest bit set */
+
+		if (cmp != 0 || *wcs1++ == L'\0')
+			break;
+	}
+
+	return cmp;
+}
+
+
+B_DEFINE_WEAK_ALIAS(__wcsncasecmp_l, wcsncasecmp_l);

src/system/libroot/posix/wchar/wcsrtombs.cpp

@@ -21,22 +21,25 @@
 #endif
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
 
 
 extern "C" size_t
 __wcsnrtombs(char* dst, const wchar_t** src, size_t nwc, size_t len,
 	mbstate_t* ps)
 {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
 	TRACE(("wcsnrtombs(%p, %p, %lu, %lu) - lb:%p\n", dst, *src, nwc, len,
-		gLocaleBackend));
+		backend));
 
 	if (ps == NULL) {
 		static mbstate_t internalMbState;
 		ps = &internalMbState;
 	}
 
-	if (gLocaleBackend == NULL) {
+	if (backend == NULL) {
 		/*
 		 * The POSIX locale is active. Since the POSIX locale only contains
 		 * chars 0-127 and those ASCII chars are compatible with the UTF32
@@ -83,7 +86,7 @@ __wcsnrtombs(char* dst, const wchar_t** src, size_t nwc, size_t len,
 	}
 
 	size_t result = 0;
-	status_t status = gLocaleBackend->WcharStringToMultibyte(dst, len, src, nwc,
+	status_t status = backend->WcharStringToMultibyte(dst, len, src, nwc,
 		ps, result);
 
 	if (status == B_BAD_DATA) {

src/system/libroot/posix/wchar/wcsxfrm.cpp

@@ -10,15 +10,19 @@
 #include <wchar_private.h>
 
 
-using BPrivate::Libroot::gLocaleBackend;
+using BPrivate::Libroot::GetCurrentLocaleBackend;
+using BPrivate::Libroot::LocaleBackend;
+using BPrivate::Libroot::LocaleBackendData;
 
 
 extern "C" size_t
 __wcsxfrm(wchar_t* dest, const wchar_t* src, size_t destSize)
 {
-	if (gLocaleBackend != NULL) {
+	LocaleBackend* backend = GetCurrentLocaleBackend();
+
+	if (backend != NULL) {
 		size_t outSize = 0;
-		status_t status = gLocaleBackend->Wcsxfrm(dest, src, destSize, outSize);
+		status_t status = backend->Wcsxfrm(dest, src, destSize, outSize);
 
 		if (status != B_OK)
 			__set_errno(EINVAL);
@@ -31,3 +35,26 @@ __wcsxfrm(wchar_t* dest, const wchar_t* src, size_t destSize)
 
 
 B_DEFINE_WEAK_ALIAS(__wcsxfrm, wcsxfrm);
+
+
+extern "C" size_t
+__wcsxfrm_l(wchar_t* dest, const wchar_t* src, size_t destSize, locale_t l)
+{
+	LocaleBackendData* locale = (LocaleBackendData*)l;
+	LocaleBackend* backend = locale->backend;
+
+	if (backend != NULL) {
+		size_t outSize = 0;
+		status_t status = backend->Wcsxfrm(dest, src, destSize, outSize);
+
+		if (status != B_OK)
+			__set_errno(EINVAL);
+
+		return outSize;
+	}
+
+	return wcslcpy(dest, src, destSize);
+}
+
+
+B_DEFINE_WEAK_ALIAS(__wcsxfrm_l, wcsxfrm_l);

src/system/runtime_loader/Jamfile

@@ -51,6 +51,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			<src!system!libroot!posix!$(architecture)>fcntl.o
 
 			<src!system!libroot!posix!locale!$(architecture)>ctype.o
+			<src!system!libroot!posix!locale!$(architecture)>ctype_loc.o
 			<src!system!libroot!posix!locale!$(architecture)>LocaleData.o
 
 			<src!system!libroot!posix!string!$(architecture)>memchr.o