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#ifndef CYGONCE_KERNEL_CLOCK_HXX

#define CYGONCE_KERNEL_CLOCK_HXX

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

//

//      clock.hxx

//

//      Clock and Alarm class declaration(s)

//

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

//####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

// Software Foundation; either version 2 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// 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

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 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

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// in accordance with section (3) of the GNU General Public License.

//

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// this file might be covered by the GNU General Public License.

//

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// at http://sources.redhat.com/ecos/ecos-license/

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

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):   nickg

// Contributors:        nickg

// Date:        1997-09-09

// Purpose:     Define Clock and Alarm class interfaces

// Description: The classes defined here collectively implement the

//              internal API used to create, configure and manage Counters,

//              Clocks and Alarms.

// Usage:       #include 

//

//####DESCRIPTIONEND####

//

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

#include 

#include             // assertion macros

#include 

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

// Forward definitions and typedefs.

class Cyg_Alarm;

typedef void cyg_alarm_fn(Cyg_Alarm *alarm, CYG_ADDRWORD data);

typedef Cyg_CList_T Cyg_Alarm_List;

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

// Counter object.

class Cyg_Counter

{

    friend class Cyg_Alarm;

#if defined(CYGIMP_KERNEL_COUNTERS_SINGLE_LIST)

    Cyg_Alarm_List      alarm_list;     // Linear list of Alarms

#elif defined(CYGIMP_KERNEL_COUNTERS_MULTI_LIST)

    Cyg_Alarm_List      alarm_list[CYGNUM_KERNEL_COUNTERS_MULTI_LIST_SIZE];

#endif

    volatile cyg_tick_count counter;    // counter value

    cyg_uint32          increment;      // increment per tick

public:

    CYGDBG_DEFINE_CHECK_THIS

    Cyg_Counter(

        cyg_uint32      increment = 1

    );

    ~Cyg_Counter();

    // Return current value of counter

    cyg_tick_count current_value();

    // Return low and high halves of the

    // counter value.

    cyg_uint32 current_value_lo();

    cyg_uint32 current_value_hi();

    // Set the counter's current value

    void set_value( cyg_tick_count new_value);

    // Advance counter by some number of ticks

    void tick( cyg_uint32 ticks = 1);

    // Add an alarm to this counter

    void add_alarm( Cyg_Alarm *alarm );

    // Remove an alarm from this counter

    void rem_alarm( Cyg_Alarm *alarm );

};

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

// Clock class. This is derived from a Counter and defines extra

// features to support clock-like behaviour.

class Cyg_Clock

    : public Cyg_Counter

{

public:

    CYGDBG_DEFINE_CHECK_THIS

    // This structure allows a more accurate representation

    // of the resolution than a single integer would allow.

    // The resolution is defined as dividend/divisor nanoseconds

    // per tick.

    struct cyg_resolution {

        cyg_uint32  dividend;

        cyg_uint32  divisor;

    };

private:

    cyg_resolution      resolution;     // Current clock resolution

public:

    Cyg_Clock(                          // Create clock with given resolution

        cyg_resolution resolution

        );

    ~Cyg_Clock();                       // Destructor

    cyg_resolution get_resolution();    // Return current resolution

    void set_resolution(                // Set new resolution

        cyg_resolution resolution

        );

    // There is a need for converting from "other" ticks to clock ticks.

    // We will construct 4 numbers to do the conversion as:

    //   clock_ticks = (((otherticks*mul1)/div1)*mul2/div2)

    // with the values chosen to minimize the possibility of overflow.

    // Do the arithmetic in cyg_uint64s throughout.

    struct converter {

        cyg_uint64 mul1, div1, mul2, div2;

    };

    // There are two of these because the 4 numbers are different depending

    // on the direction of the conversion, to prevent loss of significance.

    // NB these relate to the resolution of the clock object they are

    // called against, not necessarily "the" system real time clock.

    void get_other_to_clock_converter( cyg_uint64 ns_per_other_tick,

                                       struct converter *pcc );

    void get_clock_to_other_converter( cyg_uint64 ns_per_other_tick,

                                       struct converter *pcc );

    // A utility to perform the conversion in the obvious way, with

    // rounding to nearest at each stage.  Static because it uses a

    // previously acquired converter.

    static cyg_tick_count convert( cyg_tick_count value,

                                   struct converter *pcc );

#ifdef CYGVAR_KERNEL_COUNTERS_CLOCK

    // There is a system supplied real time clock...

    static Cyg_Clock *real_time_clock;

#endif

};

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

// Alarm class. An alarm may be attached to a counter (or a clock) to be

// called when the trigger value is reached.

class Cyg_Alarm

#if defined(CYGIMP_KERNEL_COUNTERS_SINGLE_LIST) || defined(CYGIMP_KERNEL_COUNTERS_MULTI_LIST)

    : public Cyg_DNode_T

#endif

{

    friend class Cyg_Counter;

protected:

    Cyg_Counter         *counter;       // Attached to this counter/clock

    cyg_alarm_fn        *alarm;         // Call-back function

    CYG_ADDRWORD        data;           // Call-back data

    cyg_tick_count      trigger;        // Absolute trigger time

    cyg_tick_count      interval;       // Retrigger interval

    cyg_bool            enabled;        // True if enabled

    Cyg_Alarm();

    void synchronize( void );           // deal with times in the past,

                                        // make next alarm in synch.

public:

    CYGDBG_DEFINE_CHECK_THIS

    Cyg_Alarm                           // Constructor

    (

        Cyg_Counter     *counter,       // Attached to this counter

        cyg_alarm_fn    *alarm,         // Call-back function

        CYG_ADDRWORD    data            // Call-back data

        );

    ~Cyg_Alarm();                       // Destructor

    void initialize(                    // Initialize Alarm

        cyg_tick_count    trigger,      // Absolute trigger time

        cyg_tick_count    interval = 0  // Relative retrigger interval

        );

    void enable();                      // Ensure alarm enabled

    void disable();                     // Ensure alarm disabled

    void get_times(

        cyg_tick_count  *trigger,       // Next trigger time

        cyg_tick_count  *interval       // Current interval

        );

};

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

#endif // ifndef CYGONCE_KERNEL_CLOCK_HXX

// EOF clock.hxx