Revert "Tidy up locale thread safety in ECPG library."

This reverts commit 8e993bff5326b00ced137c837fce7cd1e0ecae14.

It causes various build failures on the buildfarm, to be investigated.

Discussion: https://postgr.es/m/CWZBBRR6YA8D.8EHMDRGLCKCD%40neon.tech

4 files changed, 0 insertions, 141 deletions

diff --git a/src/port/Makefile b/src/port/Makefile
index 3e51bf1bd65..f11896440d5 100644
--- a/src/port/Makefile
+++ b/src/port/Makefile
@@ -41,7 +41,6 @@ OBJS = \
 	bsearch_arg.o \
 	chklocale.o \
 	inet_net_ntop.o \
-	locale.o \
 	noblock.o \
 	path.o \
 	pg_bitutils.o \
diff --git a/src/port/locale.c b/src/port/locale.c
deleted file mode 100644
index b3d48628915..00000000000
--- a/src/port/locale.c
+++ /dev/null
@@ -1,84 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * locale.c
- *		Helper routines for thread-safe system locale usage.
- *
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  src/port/locale.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "c.h"
-
-#ifndef LC_C_LOCALE
-
-#ifndef WIN32
-#include <pthread.h>
-#else
-#include <synchapi.h>
-#endif
-
-/* A process-lifetime singleton, allocated on first need. */
-static locale_t c_locale;
-
-#ifndef WIN32
-static void
-init_c_locale_once(void)
-{
-	c_locale = newlocale(LC_ALL, "C", NULL);
-}
-#else
-static BOOL
-init_c_locale_once(PINIT_ONCE once, PVOID parameter, PVOID *context)
-{
-	c_locale = _create_locale(LC_ALL, "C");
-	return true;
-}
-#endif
-
-/*
- * Access a process-lifetime singleton locale_t object.  Use the macro
- * PG_C_LOCALE instead of calling this directly, as it can skip the function
- * call on some systems.
- */
-locale_t
-pg_get_c_locale(void)
-{
-	/*
-	 * Fast path if already initialized.  This assumes that we can read a
-	 * locale_t (in practice, a pointer) without tearing in a multi-threaded
-	 * program.
-	 */
-	if (c_locale != (locale_t) 0)
-		return c_locale;
-
-	/* Make a locale_t.  It will live until process exit. */
-	{
-#ifndef WIN32
-		static pthread_once_t once = PTHREAD_ONCE_INIT;
-
-		pthread_once(&once, init_c_locale_once);
-#else
-		static INIT_ONCE once;
-		InitOnceExecuteOnce(&once, init_c_locale_once, NULL, NULL);
-#endif
-	}
-
-	/*
-	 * It's possible that the allocation of the locale failed due to low
-	 * memory, and then (locale_t) 0 will be returned.  Users of PG_C_LOCALE
-	 * should defend against that by checking pg_ensure_c_locale() at a
-	 * convenient time, so that they can treat it as a simple constant after
-	 * that.
-	 */
-
-	return c_locale;
-}
-
-#endif							/* not LC_C_LOCALE */
diff --git a/src/port/meson.build b/src/port/meson.build
index 45954dd2808..cf7f07644b9 100644
--- a/src/port/meson.build
+++ b/src/port/meson.build
@@ -4,7 +4,6 @@ pgport_sources = [
   'bsearch_arg.c',
   'chklocale.c',
   'inet_net_ntop.c',
-  'locale.c',
   'noblock.c',
   'path.c',
   'pg_bitutils.c',
diff --git a/src/port/snprintf.c b/src/port/snprintf.c
index 376d5c906a0..f8f2018ea0c 100644
--- a/src/port/snprintf.c
+++ b/src/port/snprintf.c
@@ -109,36 +109,6 @@
 #undef	vprintf
 #undef	printf
 
-#if defined(FRONTEND)
-/*
- * Frontend code might be multi-threaded.  When calling the system snprintf()
- * for floats, we have to use either the non-standard snprintf_l() variant, or
- * save-and-restore the calling thread's locale using uselocale(), depending on
- * availability.
- */
-#if defined(HAVE_SNPRINTF_L)
-/* At least macOS and the BSDs have the snprintf_l() extension. */
-#define USE_SNPRINTF_L
-#elif defined(WIN32)
-/* Windows has a version with a different name and argument order. */
-#define snprintf_l(str, size, loc, format, ...) _snprintf_l(str, size, format, loc, __VA_ARGS__)
-#define USE_SNPRINTF_L
-#else
-/* We have to do a thread-safe save-and-restore around snprintf(). */
-#define NEED_USE_LOCALE
-#endif
-#else
-/*
- * Backend code doesn't need to worry about locales here, because LC_NUMERIC is
- * set to "C" in main() and doesn't change.  Plain old snprintf() is always OK
- * without uselocale().
- *
- * XXX If the backend were multithreaded, we would have to be 100% certain that
- * no one is calling setlocale() concurrently, even transiently, to be able to
- * keep this small optimization.
- */
-#endif
-
 /*
  * Info about where the formatted output is going.
  *
@@ -1250,9 +1220,6 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
 		 * according to == but not according to memcmp.
 		 */
 		static const double dzero = 0.0;
-#ifdef NEED_USE_LOCALE
-		locale_t	save_locale = uselocale(PG_C_LOCALE);
-#endif
 
 		if (adjust_sign((value < 0.0 ||
 						 (value == 0.0 &&
@@ -1274,11 +1241,7 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
 			fmt[2] = '*';
 			fmt[3] = type;
 			fmt[4] = '\0';
-#ifdef USE_SNPRINTF_L
-			vallen = snprintf_l(convert, sizeof(convert), PG_C_LOCALE, fmt, prec, value);
-#else
 			vallen = snprintf(convert, sizeof(convert), fmt, prec, value);
-#endif
 		}
 		else
 		{
@@ -1287,11 +1250,6 @@ fmtfloat(double value, char type, int forcesign, int leftjust,
 			fmt[2] = '\0';
 			vallen = snprintf(convert, sizeof(convert), fmt, value);
 		}
-
-#ifdef NEED_USE_LOCALE
-		uselocale(save_locale);
-#endif
-
 		if (vallen < 0)
 			goto fail;
 
@@ -1414,25 +1372,12 @@ pg_strfromd(char *str, size_t count, int precision, double value)
 		}
 		else
 		{
-#ifdef NEED_USE_LOCALE
-			locale_t	save_locale = uselocale(PG_C_LOCALE);
-#endif
-
 			fmt[0] = '%';
 			fmt[1] = '.';
 			fmt[2] = '*';
 			fmt[3] = 'g';
 			fmt[4] = '\0';
-#ifdef USE_SNPRINTF_L
-			vallen = snprintf_l(convert, sizeof(convert), PG_C_LOCALE, fmt, precision, value);
-#else
 			vallen = snprintf(convert, sizeof(convert), fmt, precision, value);
-#endif
-
-#ifdef NEED_USE_LOCALE
-			uselocale(save_locale);
-#endif
-
 			if (vallen < 0)
 			{
 				target.failed = true;