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#ifndef CYGONCE_KERNEL_LOTTERY_HXX

#define CYGONCE_KERNEL_LOTTERY_HXX

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

//

//      lottery.hxx

//

//      Lottery scheduler class declarations

//

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

//####ECOSGPLCOPYRIGHTBEGIN####

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

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//

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

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//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):   nickg

// Contributors:        nickg

// Date:        1997-09-10

// Purpose:     Define lottery scheduler implementation

// Description: The classes defined here are used as base classes

//              by the common classes that define schedulers and thread

//              things. A lottery scheduler provides each thread with a

//              share of the processor based on the number of tickets that

//              it owns.

// Usage:       Included according to configuration by

//              

//

//####DESCRIPTIONEND####

//

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

#include 

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

// Customize the scheduler

#define CYGIMP_THREAD_PRIORITY  1       // Threads have changable priorities

#define CYG_THREAD_MIN_PRIORITY 1

#define CYG_THREAD_MAX_PRIORITY 0x7FFFFFFF

// set default scheduling info value for thread constructors.

#define CYG_SCHED_DEFAULT_INFO  CYG_THREAD_MAX_PRIORITY

#error Lottery Scheduler not yet complete, do not use!!!

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

// Thread queue implementation.

// This class provides the (scheduler specific) implementation of the

// thread queue class.

class Cyg_ThreadQueue_Implementation

{

    friend class Cyg_Scheduler_Implementation;

    friend class Cyg_SchedThread_Implementation;

    Cyg_Thread *queue;

protected:

    // API used by Cyg_ThreadQueue

                                        // Add thread to queue

    void                enqueue(Cyg_Thread *thread);

                                        // return first thread on queue

    Cyg_Thread          *highpri();

                                        // remove first thread on queue

    Cyg_Thread          *dequeue();

                                        // remove specified thread from queue

    void                remove(Cyg_Thread *thread);

                                        // test if queue is empty

    cyg_bool            empty();

    void                rotate();       // Rotate the queue

};

inline cyg_bool Cyg_ThreadQueue_Implementation::empty()

{

    return queue == NULL;

}

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

// This class contains the implementation details of the scheduler, and

// provides a standard API for accessing it.

class Cyg_Scheduler_Implementation

    : public Cyg_Scheduler_Base

{

    friend class Cyg_ThreadQueue_Implementation;

    friend class Cyg_SchedThread_Implementation;

    // All runnable threads are kept on a single run queue

    // in MRU order.

    Cyg_ThreadQueue_Implementation     run_queue;

    cyg_uint32  rand_seed;

    cyg_int32   total_tickets;

protected:

    Cyg_Scheduler_Implementation();     // Constructor

    // The following functions provide the scheduler implementation

    // interface to the Cyg_Scheduler class. These are protected

    // so that only the scheduler can call them.

    // choose a new thread

    Cyg_Thread  *schedule();

    // make thread schedulable

    void        add_thread(Cyg_Thread *thread);

    // make thread un-schedulable

    void        rem_thread(Cyg_Thread *thread);

    // register thread with scheduler

    void        register_thread(Cyg_Thread *thread);

    // deregister thread

    void        deregister_thread(Cyg_Thread *thread);

    // Test the given priority for uniqueness

    cyg_bool    unique( cyg_priority priority);

#ifdef CYGSEM_KERNEL_SCHED_TIMESLICE

    // If timeslicing is enbled, define a scheduler

    // entry point to do timeslicing. This will be

    // called from the RTC DSR.

protected:

    static cyg_count32         timeslice_count;

public:

    void timeslice();

    static void reset_timeslice_count();

#endif

};

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

// Cyg_Scheduler_Implementation inlines

#ifdef CYGSEM_KERNEL_SCHED_TIMESLICE

inline void Cyg_Scheduler_Implementation::reset_timeslice_count()

{

    timeslice_count = CYGNUM_KERNEL_SCHED_TIMESLICE_TICKS;

}

#endif

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

// Scheduler thread implementation.

// This class provides the implementation of the scheduler specific parts

// of each thread.

class Cyg_SchedThread_Implementation

{

    friend class Cyg_Scheduler_Implementation;

    friend class Cyg_ThreadQueue_Implementation;

    Cyg_Thread *next;                   // next thread in queue

    Cyg_Thread *prev;                   // previous thread in queue

    void insert( Cyg_Thread *thread );  // Insert thread in front of this

    void remove();                      // remove this from queue

protected:

    cyg_priority        priority;       // current thread priority == tickets held

    cyg_priority        compensation_tickets;   // sleep compensation

    Cyg_SchedThread_Implementation(CYG_ADDRWORD sched_info);

    void yield();                       // Yield CPU to next thread

};

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

#endif // ifndef CYGONCE_KERNEL_LOTTERY_HXX

// EOF lottery.hxx