_configthreadlocale

Article
12/18/2017

The latest version of this topic can be found at _configthreadlocale.

Configures per-thread locale options.

Syntax

int _configthreadlocale(  
   int type  
);

Parameters

type
The option to set. One of the options listed in the following table.

Return Value

The previous per-thread locale status (_DISABLE_PER_THREAD_LOCALE or _ENABLE_PER_THREAD_LOCALE), or -1 on failure.

Remarks

The _configurethreadlocale function is used to control the use of thread-specific locales. Use one of these options to specify or determine the per-thread locale status:

_ENABLE_PER_THREAD_LOCALE
Make the current thread use a thread-specific locale. Subsequent calls to setlocale in this thread affect only the thread's own locale.

_DISABLE_PER_THREAD_LOCALE
Make the current thread use the global locale. Subsequent calls to setlocale in this thread affect other threads using the global locale.

0
Retrieves the current setting for this particular thread.

These functions affect the behavior of setlocale, _tsetlocale, _wsetlocale, _beginthread, and _beginthreadex. If another method is used to create threads, the locale settings have no effect on those threads.

When per-thread locale is disabled, any subsequent call to setlocale or _wsetlocale changes the locale of all threads. When per-thread locale is enabled, setlocale or _wsetlocale only affects the current thread's locale.

If you use _configurethreadlocale to enable a per-thread locale, we recommend that you call setlocale or _wsetlocale to set the preferred locale in that thread immediately afterward.

If type is not one of the values listed in the table, this function invokes the invalid parameter handler, as described in Parameter Validation. If execution is allowed to continue, this function sets errno to EINVAL and returns -1.

Requirements

Routine	Required header
`_configthreadlocale`	<locale.h>

Example

// crt_configthreadlocale.cpp  
//   
// This program demonstrates the use of _configthreadlocale when  
// using two independent threads.  
//  
// Compile by using: cl /EHsc /W4 crt_configthreadlocale.cpp 
  
#include <locale.h>  
#include <mbctype.h>  
#include <process.h>  
#include <windows.h>  
#include <stdio.h>  
#include <time.h>  
  
#define BUFF_SIZE 100  
  
// Retrieve the date and time in the current  
// locale's format.  
int get_time(unsigned char* str)  
{  
    __time64_t  ltime;  
    struct tm   thetime;  
  
    // Retieve the time  
    _time64(&ltime);  
    _gmtime64_s(&thetime, &ltime);  
  
    // Format the current time structure into a string  
    // using %#x is the long date representation,  
    // appropriate to the current locale  
    if (!strftime((char *)str, BUFF_SIZE, "%#x",   
                  (const struct tm*)&thetime))  
    {  
        printf("strftime failed!\n");  
        return -1;  
    }  
    return 0;  
}  
  
// This thread sets its locale to German  
// and prints the time.  
unsigned __stdcall SecondThreadFunc( void* /*pArguments*/ )  
{  
    unsigned char str[BUFF_SIZE];  
  
    _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);  

    // Set the thread code page  
    _setmbcp(_MB_CP_ANSI);  
  
    // Set the thread locale  
    printf("The thread locale is now set to %s.\n",  
           setlocale(LC_ALL, "German"));  
  
    // Retrieve the time string from the helper function  
    if (get_time(str) == 0)  
    {  
        printf("The time in German locale is: '%s'\n", str);  
    }  
  
    _endthreadex( 0 );  
    return 0;  
}   
  
// The main thread spawns a second thread (above) and then  
// sets the locale to English and prints the time.  
int main()  
{   
    HANDLE          hThread;  
    unsigned        threadID;  
    unsigned char   str[BUFF_SIZE];  
  
    // Enable per-thread locale causes all subsequent locale   
    // setting changes in this thread to only affect this thread.  
    _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);  
  
    // Retrieve the time string from the helper function  
    printf("The thread locale is now set to %s.\n",  
           setlocale(LC_ALL, "English"));  
  
    // Create the second thread.  
    hThread = (HANDLE)_beginthreadex( NULL, 0, &SecondThreadFunc,  
                                      NULL, 0, &threadID );  
  
    if (get_time(str) == 0)  
    {  
        // Retrieve the time string from the helper function  
        printf("The time in English locale is: '%s'\n\n", str);  
    }  
  
    // Wait for the created thread to finish.  
    WaitForSingleObject( hThread, INFINITE );  
  
    // Destroy the thread object.  
    CloseHandle( hThread );  
}

The thread locale is now set to English_United States.1252.  
The time in English locale is: 'Wednesday, May 12, 2004'  
  
The thread locale is now set to German_Germany.1252.  
The time in German locale is: 'Mittwoch, 12. Mai 2004'

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