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#ifndef CYGONCE_KERNEL_FLAG_HXX

#define CYGONCE_KERNEL_FLAG_HXX

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

//

//      flag.hxx

//

//      Flag object class declarations

//

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

//####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

// 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

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

//

// This exception does not invalidate any other reasons why a work based on

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

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

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

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

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):   hmt

// Contributors:        hmt

// Date:        1998-02-10

// Purpose:     Define Flag class interfaces

// Description: The classes defined here provide the APIs for flags.

// Usage:       #include 

//

//

//####DESCRIPTIONEND####

//

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

#include 

#include                      // assertion macros

#include                    // Cyg_Thread

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

// Flag object.  This class implements a queue of threads waiting for a

// boolean expression of the flag value (an integer) to become true; all

// relevant threads are awoken, not just the first.  A variant on this is

// the single-bit flag, which is implemented by means of default arguments.

#ifdef CYGIMP_FLAGS_16BIT

typedef cyg_uint16 Cyg_FlagValue;

#define CYG_FLAGS_SIZE 16

#endif

#ifdef CYGIMP_FLAGS_32BIT

typedef cyg_uint32 Cyg_FlagValue;

#define CYG_FLAGS_SIZE 32

#endif

#ifdef CYGIMP_FLAGS_64BIT

typedef cyg_uint64 Cyg_FlagValue;

#define CYG_FLAGS_SIZE 64

#endif

#ifndef CYG_FLAGS_SIZE

typedef cyg_uint32 Cyg_FlagValue;

#define CYG_FLAGS_SIZE 32

#endif

class Cyg_Flag

{

private:

    Cyg_FlagValue value;

    class FlagWaitInfo

    {

    public:

        Cyg_FlagValue   allmask;        // these are separate words to

        Cyg_FlagValue   anymask;        // save time in wakeup.

        Cyg_FlagValue   value_out;      // return the value that satisfied

        cyg_bool        do_clear;

        FlagWaitInfo() { value_out = 0; }

    };

    Cyg_ThreadQueue     queue;          // Queue of waiting threads

public:

    CYGDBG_DEFINE_CHECK_THIS

    Cyg_Flag( Cyg_FlagValue init = 0 ); // Constructor

    ~Cyg_Flag();                        // Destructor

    void

    setbits( Cyg_FlagValue arg = ~0 );  // -OR- the arg in

    // not inlined; this function awakens affected threads.

    void

    maskbits( Cyg_FlagValue arg = 0 );  // -AND- it in

    // this is not inlined because it needs to lock the scheduler;

    // it only really does value &= arg; nobody can be awoken in consequence.

    typedef cyg_uint8 WaitMode;

    // These values are chosen to map directly to uITRON for emulation

    // purposes:

    static const WaitMode AND = 0;      // all specified bits must be set

    static const WaitMode OR  = 2;      // any specified bit must be set

    static const WaitMode CLR = 1;      // clear value when satisfied

    static const WaitMode MASK= 3;      // might be useful

    // Wait for a match on our pattern, according to the flags given.

    // Return the matching value, or zero if interrupted.

    Cyg_FlagValue

    wait( Cyg_FlagValue pattern, WaitMode mode );

    // Wait for a match on our pattern, with an absolute timeout.

    // Return the matching value, or zero if timed out/interrupted.

    // (zero cannot match any pattern).

#ifdef CYGFUN_KERNEL_THREADS_TIMER

    Cyg_FlagValue

    wait( Cyg_FlagValue pattern, WaitMode mode,

          cyg_tick_count abs_timeout );

#endif

    // Test for a match on our pattern, according to the flags given.

    // Return the matching value if success, else zero.

    Cyg_FlagValue

    poll( Cyg_FlagValue pattern, WaitMode mode );

    inline Cyg_FlagValue

    peek()                              // Get current value

    {

        return value;                   // NOT atomic wrt threads

    }

    inline cyg_bool

    waiting()                           // Any threads waiting?

    {

        return !queue.empty();

    }

};

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

#endif // ifndef CYGONCE_KERNEL_FLAG_HXX

// EOF flag.hxx