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

//

//      signgam.cxx

//

//      Support sign of the gamma*() functions in Math library

//

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

//####ECOSGPLCOPYRIGHTBEGIN####

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

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

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

//

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// You should have received a copy of the GNU General Public License along

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//

// 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

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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 stored sign

//              of the gamma*() functions in 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_GAMMA_FUNCTIONS

# 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_GAMMA_FUNCTIONS

int signgam = 0;

#else  // ifndef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

static Cyg_Mutex cyg_libm_signgam_thread_data_index_mutex;

static cyg_count32 cyg_libm_signgam_thread_data_index = CYGNUM_KERNEL_THREADS_DATA_MAX;

# if defined(CYGDBG_USE_TRACING) && \

     defined(CYGNUM_LIBM_SIGNGAM_TRACE_LEVEL)

static int libm_signgam_trace = CYGNUM_LIBM_SIGNGAM_TRACE_LEVEL;

#  define TL1 (0 < libm_signgam_trace )

# else

#  define TL1 (0)

# endif

#endif // ifndef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

// FUNCTIONS

#ifdef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

int *

cyg_libm_get_signgam_p( void )

{

    Cyg_Thread *self = Cyg_Thread::self();

    CYG_ADDRWORD *current_val_p;

    CYG_REPORT_FUNCNAMETYPE( "Cyg_libm_get_signgam_p", "&signgam is %08x" );

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

    // initialise the thread data index

    if (cyg_libm_signgam_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_signgam_thread_data_index_mutex.lock();

        if (cyg_libm_signgam_thread_data_index == CYGNUM_KERNEL_THREADS_DATA_MAX)

        {

            CYG_TRACE0( TL1, "Allocating index" );

            cyg_libm_signgam_thread_data_index = self->new_data_index();

        } // if

        cyg_libm_signgam_thread_data_index_mutex.unlock();

    } // if

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

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

    current_val_p = self->get_data_ptr( cyg_libm_signgam_thread_data_index );

    CYG_REPORT_RETVAL( current_val_p );

    return (int *) current_val_p;

} // cyg_libm_get_signgam_p()

#endif // ifdef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

#endif // ifdef CYGPKG_LIBM

// EOF signgam.cxx