database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-22 14:32:25 +03:00
Code Activity

Tidy up locale thread safety in ECPG library.

Browse Source 
Remove setlocale() and _configthreadlocal() as fallback strategy on
systems that don't have uselocale(), where ECPG tries to control
LC_NUMERIC formatting on input and output of floating point numbers.  It
was probably broken on some systems (NetBSD), and the code was also
quite messy and complicated, with obsolete configure tests (Windows).
It was also arguably broken, or at least had unstated environmental
requirements, if pgtypeslib code was called directly.

Instead, introduce PG_C_LOCALE to refer to the "C" locale as a locale_t
value.  It maps to the special constant LC_C_LOCALE when defined by libc
(macOS, NetBSD), or otherwise uses a process-lifetime locale_t that is
allocated on first use, just as ECPG previously did itself.  The new
replacement might be more widely useful.  Then change the float parsing
and printing code to pass that to _l() functions where appropriate.

Unfortunately the portability of those functions is a bit complicated.
First, many obvious and useful _l() functions are missing from POSIX,
though most standard libraries define some of them anyway.  Second,
although the thread-safe save/restore technique can be used to replace
the missing ones, Windows and NetBSD refused to implement standard
uselocale().  They might have a point: "wide scope" uselocale() is hard
to combine with other code and error-prone, especially in library code.
Luckily they have the  _l() functions we want so far anyway.  So we have
to be prepared for both ways of doing things:

1.  In ECPG, use strtod_l() for parsing, and supply a port.h replacement
using uselocale() over a limited scope if missing.

2.  Inside our own snprintf.c, use three different approaches to format
floats.  For frontend code, call libc's snprintf_l(), or wrap libc's
snprintf() in uselocale() if it's missing.  For backend code, snprintf.c
can keep assuming that the global locale's LC_NUMERIC is "C" and call
libc's snprintf() without change, for now.

(It might eventually be possible to call our in-tree Ryū routines to
display floats in snprintf.c, given the C-locale-always remit of our
in-tree snprintf(), but this patch doesn't risk changing anything that
complicated.)

Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Tristan Partin <tristan@partin.io>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/CWZBBRR6YA8D.8EHMDRGLCKCD%40neon.tech
This commit is contained in:
Peter Eisentraut
2025-03-28 16:15:57 +01:00
parent 2247281c47
commit 8e993bff53
18 changed files with 192 additions and 148 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
src/interfaces/ecpg/ecpglib/connect.c
View File

@@ -10,10 +10,6 @@
#include "ecpgtype.h"
#include "sqlca.h"
#ifdef HAVE_USELOCALE
locale_t ecpg_clocale = (locale_t) 0;
#endif
static pthread_mutex_t connections_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_key_t actual_connection_key;
static pthread_once_t actual_connection_key_once = PTHREAD_ONCE_INIT;
@@ -268,7 +264,7 @@ ECPGconnect(int lineno, int c, const char *name, const char *user, const char *p
const char **conn_keywords;
const char **conn_values;
if (sqlca == NULL)
if (sqlca == NULL || !pg_ensure_c_locale())
{
ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
@@ -483,39 +479,6 @@ ECPGconnect(int lineno, int c, const char *name, const char *user, const char *p
/* add connection to our list */
pthread_mutex_lock(&connections_mutex);
/*
* ... but first, make certain we have created ecpg_clocale. Rely on
* holding connections_mutex to ensure this is done by only one thread.
*/
#ifdef HAVE_USELOCALE
if (!ecpg_clocale)
{
ecpg_clocale = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
if (!ecpg_clocale)
{
pthread_mutex_unlock(&connections_mutex);
ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
if (host)
ecpg_free(host);
if (port)
ecpg_free(port);
if (options)
ecpg_free(options);
if (realname)
ecpg_free(realname);
if (dbname)
ecpg_free(dbname);
if (conn_keywords)
ecpg_free(conn_keywords);
if (conn_values)
ecpg_free(conn_values);
free(this);
return false;
}
}
#endif
if (connection_name != NULL)
this->name = ecpg_strdup(connection_name, lineno);
else

2
src/interfaces/ecpg/ecpglib/data.c
View File

@@ -466,7 +466,7 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
pval++;
if (!check_special_value(pval, &dres, &scan_length))
dres = strtod(pval, &scan_length);
dres = strtod_l(pval, &scan_length, PG_C_LOCALE);
if (isarray && *scan_length == '"')
scan_length++;

37
src/interfaces/ecpg/ecpglib/descriptor.c
View File

@@ -475,46 +475,9 @@ ECPGget_desc(int lineno, const char *desc_name, int index,...)
memset(&stmt, 0, sizeof stmt);
stmt.lineno = lineno;
/* Make sure we do NOT honor the locale for numeric input */
/* since the database gives the standard decimal point */
/* (see comments in execute.c) */
#ifdef HAVE_USELOCALE
/*
* To get here, the above PQnfields() test must have found nonzero
* fields. One needs a connection to create such a descriptor. (EXEC
* SQL SET DESCRIPTOR can populate the descriptor's "items", but it
* can't change the descriptor's PQnfields().) Any successful
* connection initializes ecpg_clocale.
*/
Assert(ecpg_clocale);
stmt.oldlocale = uselocale(ecpg_clocale);
#else
#ifdef WIN32
stmt.oldthreadlocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
#endif
stmt.oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
setlocale(LC_NUMERIC, "C");
#endif
/* desperate try to guess something sensible */
stmt.connection = ecpg_get_connection(NULL);
ecpg_store_result(ECPGresult, index, &stmt, &data_var);
#ifdef HAVE_USELOCALE
if (stmt.oldlocale != (locale_t) 0)
uselocale(stmt.oldlocale);
#else
if (stmt.oldlocale)
{
setlocale(LC_NUMERIC, stmt.oldlocale);
ecpg_free(stmt.oldlocale);
}
#ifdef WIN32
if (stmt.oldthreadlocale != -1)
_configthreadlocale(stmt.oldthreadlocale);
#endif
#endif
}
else if (data_var.ind_type != ECPGt_NO_INDICATOR && data_var.ind_pointer != NULL)

12
src/interfaces/ecpg/ecpglib/ecpglib_extern.h
View File

@@ -56,10 +56,6 @@ struct ECPGtype_information_cache
enum ARRAY_TYPE isarray;
};
#ifdef HAVE_USELOCALE
extern locale_t ecpg_clocale; /* LC_NUMERIC=C */
#endif
/* structure to store one statement */
struct statement
{
@@ -73,14 +69,6 @@ struct statement
bool questionmarks;
struct variable *inlist;
struct variable *outlist;
#ifdef HAVE_USELOCALE
locale_t oldlocale;
#else
char *oldlocale;
#ifdef WIN32
int oldthreadlocale;
#endif
#endif
int nparams;
char **paramvalues;
int *paramlengths;

53
src/interfaces/ecpg/ecpglib/execute.c
View File

@@ -101,9 +101,6 @@ free_statement(struct statement *stmt)
free_variable(stmt->outlist);
ecpg_free(stmt->command);
ecpg_free(stmt->name);
#ifndef HAVE_USELOCALE
ecpg_free(stmt->oldlocale);
#endif
ecpg_free(stmt);
}
@@ -1973,43 +1970,6 @@ ecpg_do_prologue(int lineno, const int compat, const int force_indicator,
if (stmt == NULL)
return false;
/*
* Make sure we do NOT honor the locale for numeric input/output since the
* database wants the standard decimal point. If available, use
* uselocale() for this because it's thread-safe. Windows doesn't have
* that, but it does have _configthreadlocale().
*/
#ifdef HAVE_USELOCALE
/*
* Since ecpg_init() succeeded, we have a connection. Any successful
* connection initializes ecpg_clocale.
*/
Assert(ecpg_clocale);
stmt->oldlocale = uselocale(ecpg_clocale);
if (stmt->oldlocale == (locale_t) 0)
{
ecpg_do_epilogue(stmt);
return false;
}
#else
#ifdef WIN32
stmt->oldthreadlocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
if (stmt->oldthreadlocale == -1)
{
ecpg_do_epilogue(stmt);
return false;
}
#endif
stmt->oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
if (stmt->oldlocale == NULL)
{
ecpg_do_epilogue(stmt);
return false;
}
setlocale(LC_NUMERIC, "C");
#endif
/*
* If statement type is ECPGst_prepnormal we are supposed to prepare the
* statement before executing them
@@ -2216,19 +2176,6 @@ ecpg_do_epilogue(struct statement *stmt)
if (stmt == NULL)
return;
#ifdef HAVE_USELOCALE
if (stmt->oldlocale != (locale_t) 0)
uselocale(stmt->oldlocale);
#else
if (stmt->oldlocale)
{
setlocale(LC_NUMERIC, stmt->oldlocale);
#ifdef WIN32
_configthreadlocale(stmt->oldthreadlocale);
#endif
}
#endif
free_statement(stmt);
}

6
src/interfaces/ecpg/pgtypeslib/dt_common.c
View File

@@ -1218,7 +1218,7 @@ DecodeNumber(int flen, char *str, int fmask,
return DecodeNumberField(flen, str, (fmask | DTK_DATE_M),
tmask, tm, fsec, is2digits);
*fsec = strtod(cp, &cp);
*fsec = strtod_l(cp, &cp, PG_C_LOCALE);
if (*cp != '\0')
return -1;
}
@@ -2030,7 +2030,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
{
double frac;
frac = strtod(cp, &cp);
frac = strtod_l(cp, &cp, PG_C_LOCALE);
if (*cp != '\0')
return -1;
*fsec = frac * 1000000;
@@ -2054,7 +2054,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
{
double time;
time = strtod(cp, &cp);
time = strtod_l(cp, &cp, PG_C_LOCALE);
if (*cp != '\0')
return -1;

4
src/interfaces/ecpg/pgtypeslib/interval.c
View File

@@ -60,7 +60,7 @@ ParseISO8601Number(const char *str, char **endptr, int *ipart, double *fpart)
if (!(isdigit((unsigned char) *str) || *str == '-' || *str == '.'))
return DTERR_BAD_FORMAT;
errno = 0;
val = strtod(str, endptr);
val = strtod_l(str, endptr, PG_C_LOCALE);
/* did we not see anything that looks like a double? */
if (*endptr == str || errno != 0)
return DTERR_BAD_FORMAT;
@@ -455,7 +455,7 @@ DecodeInterval(char **field, int *ftype, int nf, /* int range, */
else if (*cp == '.')
{
errno = 0;
fval = strtod(cp, &cp);
fval = strtod_l(cp, &cp, PG_C_LOCALE);
if (*cp != '\0' || errno != 0)
return DTERR_BAD_FORMAT;

2
src/interfaces/ecpg/pgtypeslib/numeric.c
View File

@@ -1455,7 +1455,7 @@ numericvar_to_double(numeric *var, double *dp)
* strtod does not reset errno to 0 in case of success.
*/
errno = 0;
val = strtod(tmp, &endptr);
val = strtod_l(tmp, &endptr, PG_C_LOCALE);
if (errno == ERANGE)
{
free(tmp);