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

//

//      compatmode.cxx

//

//      Compatibility mode setting for Math library

//

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

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos 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

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// 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

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// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

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// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):   jlarmour

// Contributors:  jlarmour

// Date:        1998-02-13

// Purpose:     

// Description: Contains the accessor functions to get and set the standards

//              compatibility mode of the Math library

// Usage:       

//

//####DESCRIPTIONEND####

//

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

// CONFIGURATION

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

// Include the Math library?

#ifdef CYGPKG_LIBM

// INCLUDES

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

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

#include <math.h>                  // Main header for math library

#ifdef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

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

# include <cyg/kernel/thread.hxx>   // Kernel thread header

# include <cyg/kernel/thread.inl>   // and its associated inlines

# include <cyg/kernel/mutex.hxx>    // We need mutexes too

#endif

// GLOBAL VARIABLES

#ifndef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

# ifdef CYGSEM_LIBM_COMPAT_IEEE_ONLY

Cyg_libm_compat_t cygvar_libm_compat_mode = CYGNUM_LIBM_COMPAT_IEEE;

# else

Cyg_libm_compat_t cygvar_libm_compat_mode = CYGNUM_LIBM_COMPAT_DEFAULT;

# endif

#else  // ifndef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

static Cyg_Mutex cyg_libm_mode_thread_data_index_mutex;

static cyg_count32 cyg_libm_mode_thread_data_index = CYGNUM_KERNEL_THREADS_DATA_MAX;

# if defined(CYGDBG_USE_TRACING) && \

     defined(CYGNUM_LIBM_COMPATMODE_TRACE_LEVEL)

static int libm_compatmode_trace = CYGNUM_LIBM_COMPATMODE_TRACE_LEVEL;

#  define TL1 (0 < libm_compatmode_trace )

# else

#  define TL1 (0)

# endif

// FUNCTIONS

Cyg_libm_compat_t

cyg_libm_get_compat_mode( void )

{

    Cyg_Thread *self = Cyg_Thread::self();

    CYG_ADDRWORD current_val;

    CYG_REPORT_FUNCNAMETYPE( "Cyg_libm_get_compat_mode", "mode is %d" );

    // First check if this is the first thread to get here, and if so,

    // initialise the thread data index

    if (cyg_libm_mode_thread_data_index == CYGNUM_KERNEL_THREADS_DATA_MAX)

    {

        CYG_TRACE0( TL1, "Index unset, locking mutex to allocate" );

        // Lock mutex and then check again - less overhead for normal

        // execution path

        cyg_libm_mode_thread_data_index_mutex.lock();

        if (cyg_libm_mode_thread_data_index == CYGNUM_KERNEL_THREADS_DATA_MAX)

        {

            CYG_TRACE0( TL1, "Allocating index" );

            cyg_libm_mode_thread_data_index = self->new_data_index();

        } // if

        cyg_libm_mode_thread_data_index_mutex.unlock();

        self->set_data( cyg_libm_mode_thread_data_index,

                        CYGNUM_LIBM_COMPAT_DEFAULT );

        // But if we've gone through this, then we know what the mode is!

        CYG_REPORT_RETVAL( CYGNUM_LIBM_COMPAT_DEFAULT );

        return CYGNUM_LIBM_COMPAT_DEFAULT;

    } // if

    CYG_TRACE0( TL1, "Index set, now fetching per-thread data" );

    // If we're here, then the index is set up

    current_val = self->get_data( cyg_libm_mode_thread_data_index );

    // If its at the "default" setting, then return the default

    if (current_val == CYGNUM_LIBM_COMPAT_UNINIT)

    {

        CYG_REPORT_RETVAL( CYGNUM_LIBM_COMPAT_DEFAULT );

        return CYGNUM_LIBM_COMPAT_DEFAULT;

    } // if

    CYG_REPORT_RETVAL( current_val );

    return (Cyg_libm_compat_t) current_val;

} // cyg_libm_get_compat_mode()

Cyg_libm_compat_t

cyg_libm_set_compat_mode( Cyg_libm_compat_t new_mode )

{

    Cyg_Thread *self = Cyg_Thread::self();

    CYG_ADDRWORD current_val;

    CYG_REPORT_FUNCNAMETYPE( "Cyg_libm_set_compat_mode", "old mode was %d" );

    CYG_REPORT_FUNCARG1DV( new_mode );

    // First check if this is the first thread to get here, and if so,

    // initialise the thread data index

    if (cyg_libm_mode_thread_data_index == CYGNUM_KERNEL_THREADS_DATA_MAX)

    {

        CYG_TRACE0( TL1, "Index unset, locking mutex to allocate" );

        // Lock mutex and then check again - less overhead for normal

        // execution path

        cyg_libm_mode_thread_data_index_mutex.lock();

        if (cyg_libm_mode_thread_data_index == CYGNUM_KERNEL_THREADS_DATA_MAX)

        {

            CYG_TRACE0( TL1, "Allocating index" );

            cyg_libm_mode_thread_data_index = self->new_data_index();

        } // if

        cyg_libm_mode_thread_data_index_mutex.unlock();

        self->set_data( cyg_libm_mode_thread_data_index,

                        new_mode );

        // But if we've gone through this, then we know what the old mode was!

        CYG_REPORT_RETVAL( CYGNUM_LIBM_COMPAT_UNINIT );

        return CYGNUM_LIBM_COMPAT_UNINIT;

    } // if

    // If we're here, then the index is set up

    CYG_TRACE0( TL1, "Index set, now fetching per-thread data" );

    current_val = self->get_data( cyg_libm_mode_thread_data_index );

    self->set_data( cyg_libm_mode_thread_data_index,

                    new_mode );

    CYG_REPORT_RETVAL( current_val );

    return (Cyg_libm_compat_t) current_val;

} // cyg_libm_set_compat_mode()

#endif // ifdef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

#endif // ifdef CYGPKG_LIBM

// EOF compatmode.cxx