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//===========================================================================

//

//      mblen.cxx

//

//      ISO standard mblen() routine 

//

//===========================================================================

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//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     jjohnstn

// Contributors:  jjohnstn

// Date:          2000-11-01

// Purpose:       Provide ISO C mblen()

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//===========================================================================

//

// This code was based on newlib/libc/stdlib/mblen.c

// The following is modified from the original newlib description:

//

/*

FUNCTION

<<mblen>>---multibyte length function

INDEX

        mblen

ANSI_SYNOPSIS

        #include <stdlib.h>

        int mblen(const char *<[s]>, size_t <[n]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        int mblen(<[s]>, <[n]>)

        const char *<[s]>;

        size_t <[n]>;

DESCRIPTION

When CYGINT_LIBC_I18N_MB_REQUIRED is not defined, this is a minimal ANSI-conforming

implementation of <<mblen>>.  In this case, the

only ``multi-byte character sequences'' recognized are single bytes,

and thus <<1>> is returned unless <[s]> is the null pointer or

has a length of 0 or is the empty string.

When CYGINT_LIBC_I18N_MB_REQUIRED is defined, this routine calls the locale's LC_CTYPE mbtowc_fn to perform

the conversion, passing a state variable to allow state dependent

decoding.  The result is based on the locale setting which may

be restricted to a defined set of locales.

RETURNS

This implementation of <<mblen>> returns <<0>> if

<[s]> is <<NULL>> or the empty string; it returns <<1>> if not CYGINT_LIBC_I18N_MB_REQUIRED or

the character is a single-byte character; it returns <<-1>>

if the multi-byte character is invalid; otherwise it returns

the number of bytes in the multibyte character.

PORTABILITY

<<mblen>> is required in the ANSI C standard.  However, the precise

effects vary with the locale.

<<mblen>> requires no supporting OS subroutines.

*/

// CONFIGURATION

#include <pkgconf/libc_i18n.h>     // Configuration header

// INCLUDES

#include <cyg/infra/cyg_type.h>    // Common type definitions

#include <cyg/infra/cyg_trac.h>    // Tracing support

#include <cyg/infra/cyg_ass.h>     // Assertion support

#include <locale.h>

#include <stdlib.h>                // Header for this file

#include <string.h>                // strcmp definition

#include <stddef.h>                // size_t definition

#include "internal.h"              // __current_ctype_locale definition

#ifdef CYGSEM_LIBC_I18N_PER_THREAD_MB

# include <pkgconf/kernel.h>       // kernel configuration

# include <cyg/kernel/thread.hxx>  // per-thread data

# include <cyg/kernel/thread.inl>  // per-thread data

# include <cyg/kernel/mutex.hxx>   // mutexes

#endif /* CYGSEM_LIBC_I18N_PER_THREAD_MB */

// TRACE

#if defined(CYGDBG_USE_TRACING) && defined(CYGNUM_LIBC_I18N_MBLEN_TRACE_LEVEL)

static int mblen_trace = CYGNUM_LIBC_I18N_MBLEN_TRACE_LEVEL;

# define TL1 (0 < mblen_trace)

#else

# define TL1 (0)

#endif

// STATICS

#ifdef CYGINT_LIBC_I18N_MB_REQUIRED

# ifdef CYGSEM_LIBC_I18N_PER_THREAD_MB

static volatile cyg_ucount32 mblen_data_index=CYGNUM_KERNEL_THREADS_DATA_MAX;

static Cyg_Mutex mblen_data_mutex CYG_INIT_PRIORITY(LIBC);

# else

static int cyg_libc_mblen_last;

# endif

#endif

// FUNCTIONS

int

mblen ( const char *s, size_t n )

{

#ifdef CYGINT_LIBC_I18N_MB_REQUIRED

  int  *state;

#endif

  int   retval;

  CYG_REPORT_FUNCNAMETYPE( "mblen", "returning %d" );

  CYG_REPORT_FUNCARG2( "s=%08x, n=%ud", s, n );

  if (s != NULL)

    CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" );

#ifdef CYGINT_LIBC_I18N_MB_REQUIRED

#ifdef CYGSEM_LIBC_I18N_PER_THREAD_MB

  Cyg_Thread *self = Cyg_Thread::self();

  // Get a per-thread data slot if we haven't got one already

  // Do a simple test before locking and retrying test, as this is a

  // rare situation

  if (CYGNUM_KERNEL_THREADS_DATA_MAX==mblen_data_index) {

    mblen_data_mutex.lock();

    if (CYGNUM_KERNEL_THREADS_DATA_MAX==mblen_data_index) {

      // the kernel just throws an assert if this doesn't work

      // FIXME: Should use real CDL to pre-allocate a slot at compile

      // time to ensure there are enough slots

      mblen_data_index = self->new_data_index();

    }

    mblen_data_mutex.unlock();

  } // if

  // we have a valid index now

  state = (int *)self->get_data_ptr(mblen_data_index);

#else  /* not CYGSEM_LIBC_I18N_PER_THREAD_MB */

  state = &cyg_libc_mblen_last;

#endif /* not CYGSEM_LIBC_I18N_PER_THREAD_MB */

  CYG_TRACE2( TL1, "Retrieved mblen_last address %08x containing %d",

              state, *state );

  if (__current_ctype_locale->mbtowc_fn)

    {

      retval = __current_ctype_locale->mbtowc_fn (NULL, s, n, state);

      CYG_REPORT_RETVAL( retval );

      return retval;

    }

#endif /* CYGINT_LIBC_I18N_MB_REQUIRED */

  if (s == NULL || *s == '\0')

    retval = 0;

  else if (n == 0)

    retval = -1;

  else

    retval = 1;

  CYG_REPORT_RETVAL( retval );

  return retval;

} // mblen()

// EOF mblen.cxx