POSIX [1] says about localeconv(): "The localeconv() function need not be thread-safe; however, localeconv() shall avoid data races with all other functions."
[1] https://pubs.opengroup.org/onlinepubs/9799919799/functions/localeconv.html It's not exactly clear to me what this means. What is relevant for library code is that one can call localeconv() and access the elements of the result, when no other thread calls setlocale() or the same thread does not call uselocale(). I'm adding a unit test for this property. It passes on all tested platforms (except that it is SKIPped on AIX 7.1 due to lack of locales for testing). 2025-04-12 Bruno Haible <br...@clisp.org> localeconv tests: Add multithread-safety test. * tests/test-localeconv-mt.c: New file, based on tests/test-nl_langinfo-mt.c. * modules/localeconv-tests (Files): Add it. (Depends-on): Add setlocale, thread, nanosleep. (Makefile.am): Arrange to compile and run test-localeconv-mt. diff --git a/modules/localeconv-tests b/modules/localeconv-tests index 621696a1e1..503f694688 100644 --- a/modules/localeconv-tests +++ b/modules/localeconv-tests @@ -1,12 +1,17 @@ Files: tests/test-localeconv.c +tests/test-localeconv-mt.c tests/signature.h tests/macros.h Depends-on: +setlocale +thread +nanosleep configure.ac: Makefile.am: -TESTS += test-localeconv -check_PROGRAMS += test-localeconv +TESTS += test-localeconv test-localeconv-mt +check_PROGRAMS += test-localeconv test-localeconv-mt +test_localeconv_mt_LDADD = $(LDADD) $(SETLOCALE_LIB) $(LIBMULTITHREAD) $(NANOSLEEP_LIB) ========================== tests/test-localeconv-mt.c ========================== /* Multithread-safety test for localeconv() (in the absence of setlocale() or uselocale() calls). Copyright (C) 2019-2025 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* Written by Bruno Haible <br...@clisp.org>, 2025. */ #include <config.h> /* Work around GCC bug 44511. */ #if _GL_GNUC_PREREQ (4, 3) # pragma GCC diagnostic ignored "-Wreturn-type" #endif #if USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS /* Specification. */ #include <locale.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> #include "glthread/thread.h" /* Some common locale names. */ #if defined _WIN32 && !defined __CYGWIN__ # define ENGLISH "English_United States" # define FRENCH "French_France" # define GERMAN "German_Germany" # define ENCODING ".1252" #else # define ENGLISH "en_US" # define FRENCH "fr_FR" # define GERMAN "de_DE" # if defined __sgi # define ENCODING ".ISO8859-15" # elif defined __hpux # define ENCODING ".utf8" # else # define ENCODING ".UTF-8" # endif #endif static const char LOCALE1[] = ENGLISH ENCODING; static const char LOCALE2[] = FRENCH ENCODING; static const char LOCALE3[] = GERMAN ENCODING; static char *expected1; static void * thread1_func (void *arg) { for (;;) { const char *value = localeconv () -> decimal_point; if (strcmp (expected1, value) != 0) { fprintf (stderr, "thread1 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static char *expected2; static void * thread2_func (void *arg) { for (;;) { const char *value = localeconv () -> thousands_sep; if (strcmp (expected2, value) != 0) { fprintf (stderr, "thread2 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static char *expected3; static void * thread3_func (void *arg) { for (;;) { const char *value = localeconv () -> mon_decimal_point; if (strcmp (expected3, value) != 0) { fprintf (stderr, "thread3 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static char *expected4; static void * thread4_func (void *arg) { for (;;) { const char *value = localeconv () -> mon_thousands_sep; if (strcmp (expected4, value) != 0) { fprintf (stderr, "thread4 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static char *expected5; static void * thread5_func (void *arg) { for (;;) { const char *value = localeconv () -> currency_symbol; if (strcmp (expected5, value) != 0) { fprintf (stderr, "thread5 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static char *expected6; static void * thread6_func (void *arg) { for (;;) { const char *value = localeconv () -> int_curr_symbol; if (strcmp (expected6, value) != 0) { fprintf (stderr, "thread6 disturbed by threadN!\n"); fflush (stderr); abort (); } } /*NOTREACHED*/ } static void * threadN_func (void *arg) { for (;;) { (void) localeconv () -> decimal_point; /* LC_NUMERIC */ /* locale -k decimal_point */ (void) localeconv () -> thousands_sep; /* LC_NUMERIC */ /* locale -k thousands_sep */ (void) localeconv () -> mon_decimal_point; /* LC_MONETARY */ /* locale -k mon_decimal_point */ (void) localeconv () -> mon_thousands_sep; /* LC_MONETARY */ /* locale -k mon_thousands_sep */ (void) localeconv () -> currency_symbol; /* LC_MONETARY */ /* locale -k currency_symbol */ (void) localeconv () -> int_curr_symbol; /* LC_MONETARY */ /* locale -k int_curr_symbol */ } /*NOTREACHED*/ } int main (int argc, char *argv[]) { if (setlocale (LC_ALL, LOCALE1) == NULL) { fprintf (stderr, "Skipping test: LOCALE1 not recognized\n"); return 77; } if (setlocale (LC_MONETARY, LOCALE2) == NULL) { fprintf (stderr, "Skipping test: LOCALE2 not recognized\n"); return 77; } if (setlocale (LC_NUMERIC, LOCALE3) == NULL) { fprintf (stderr, "Skipping test: LOCALE3 not recognized\n"); return 77; } expected1 = strdup (localeconv () -> decimal_point); expected2 = strdup (localeconv () -> thousands_sep); expected3 = strdup (localeconv () -> mon_decimal_point); expected4 = strdup (localeconv () -> mon_thousands_sep); expected5 = strdup (localeconv () -> currency_symbol); expected6 = strdup (localeconv () -> int_curr_symbol); /* Create the checker threads. */ gl_thread_create (thread1_func, NULL); gl_thread_create (thread2_func, NULL); gl_thread_create (thread3_func, NULL); gl_thread_create (thread4_func, NULL); gl_thread_create (thread5_func, NULL); gl_thread_create (thread6_func, NULL); /* Create the disturber thread. */ gl_thread_create (threadN_func, NULL); /* Let them run for 2 seconds. */ { struct timespec duration; duration.tv_sec = (argc > 1 ? atoi (argv[1]) : 2); duration.tv_nsec = 0; nanosleep (&duration, NULL); } return 0; } #else /* No multithreading available. */ #include <stdio.h> int main () { fputs ("Skipping test: multithreading not enabled\n", stderr); return 77; } #endif
