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

//

//      clock.cxx

//

//      ISO C date and time implementation for clock()

//

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

//####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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//

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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

// License. However the source code for this file must still be made available

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

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):    jlarmour

// Contributors: jlarmour

// Date:         1999-03-05

// Purpose:      Provides an implementation of the ISO C function clock()

//               from ISO C section 7.12.2.1

// Description:  This file uses the kernel real time clock to determine

//               the complete running time of the system - since we only

//               have one task, even though there are perhaps multiple threads

//               that is still the running time of the "program"

// Usage:       

//

//####DESCRIPTIONEND####

//

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

// CONFIGURATION

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

#ifdef CYGSEM_LIBC_TIME_CLOCK_WORKING

# include <pkgconf/kernel.h> // Kernel config header

#endif

// INCLUDES

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

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

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

#include <time.h>                  // Header for all time-related functions

#ifdef CYGSEM_LIBC_TIME_CLOCK_WORKING

# include <cyg/kernel/clock.hxx>   // Kernel clock definitions

# include <cyg/kernel/clock.inl>   // Kernel clock inline functions

#endif

// TRACE

# if defined(CYGDBG_USE_TRACING) && defined(CYGNUM_LIBC_TIME_CLOCK_TRACE_LEVEL)

static int clock_trace = CYGNUM_LIBC_TIME_CLOCK_TRACE_LEVEL;

#  define TL1 (0 < clock_trace)

# else

#  define TL1 (0)

# endif

// FUNCTIONS

externC clock_t

clock( void )

{

    CYG_REPORT_FUNCNAMETYPE( "clock", "returning clock tick %d" );

    CYG_REPORT_FUNCARGVOID();

#ifdef CYGSEM_LIBC_TIME_CLOCK_WORKING

    cyg_tick_count curr_clock;            // kernel clock value

    Cyg_Clock::cyg_resolution resolution; // kernel clock resolution

    clock_t clocks;

    unsigned long long temp;

    CYG_TRACE0( TL1, "getting clock resolution" );

    // get the resolution

    resolution = Cyg_Clock::real_time_clock->get_resolution();

    CYG_TRACE2( TL1, "got resolution dividend %d divisor %d. Getting "

                "clock value", resolution.dividend, resolution.divisor );

    // get the value

    curr_clock = Cyg_Clock::real_time_clock->current_value();

    CYG_TRACE1( TL1, "got clock value %d", curr_clock );

    // scale the value so that clock()/CLOCKS_PER_SEC works

    // We use an unsigned long long to avoid overflow as the dividend

    // and divisors tend to be huge

    temp = (1000000000 / CLOCKS_PER_SEC);

    temp *= resolution.divisor;

    temp = (unsigned long long)curr_clock * resolution.dividend / temp;

    clocks = (clock_t)temp;

    CYG_REPORT_RETVAL( clocks );

    return clocks;

#else // i.e. ifndef CYGSEM_LIBC_TIME_CLOCK_WORKING

    CYG_REPORT_RETVAL( -1 );

    return (clock_t) -1;

#endif

} // clock()

// EOF clock.cxx