mfiximpl.hxx

eCos操作系统源码

#ifndef CYGONCE_MEMALLOC_MFIXIMPL_HXX
#define CYGONCE_MEMALLOC_MFIXIMPL_HXX

//==========================================================================
//
//      mfiximpl.hxx
//
//      Memory pool with fixed block 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: jlarmour
// Date:         2000-06-12
// Purpose:      Define Mfiximpl class interface
// Description:  Inline class for constructing a fixed block allocator
// Usage:        #include <cyg/memalloc/mfiximpl.hxx>
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <cyg/infra/cyg_type.h>
#include <cyg/memalloc/common.hxx>     // Common memory allocator infra

class Cyg_Mempool_Fixed_Implementation {
protected:
    // these constructors are explicitly disallowed
    Cyg_Mempool_Fixed_Implementation() {};
//    Cyg_Mempool_Fixed_Implementation( Cyg_Mempool_Fixed_Implementation &ref )
//    {};
    Cyg_Mempool_Fixed_Implementation &
    operator=( Cyg_Mempool_Fixed_Implementation &ref )
    { return ref; };

    cyg_uint32 *bitmap;
    cyg_int32 maptop;
    cyg_uint8  *mempool;
    cyg_int32 numblocks;
    cyg_int32 freeblocks;
    cyg_int32 blocksize;
    cyg_int32 firstfree;
    cyg_uint8  *top;

public:
    // THIS is the public API of memory pools generally that can have the
    // kernel oriented thread-safe package layer atop.
    //
    // The kernel package is a template whose type parameter is one of
    // these.  That is the reason there are superfluous parameters here and
    // more genereralization than might be expected in a fixed block
    // allocator.

    // Constructor: gives the base and size of the arena in which memory is
    // to be carved out, note that management structures are taken from the
    // same arena.  The alloc_unit may be any other param in general; it
    // comes through from the outer constructor unchanged.
    Cyg_Mempool_Fixed_Implementation(
        cyg_uint8 *base,
        cyg_int32 size,
        CYG_ADDRWORD alloc_unit );

    // Destructor
    ~Cyg_Mempool_Fixed_Implementation();

    // get some memory; size is ignored in a fixed block allocator
    cyg_uint8 *try_alloc( cyg_int32 size );
    
    // supposedly resize existing allocation. This is defined in the
    // fixed block allocator purely for API consistency. It will return
    // an error (false) for all values, except for the blocksize
    // returns true on success
    cyg_uint8 *
    resize_alloc( cyg_uint8 *alloc_ptr, cyg_int32 newsize,
                  cyg_int32 *oldsize=NULL );

    // free the memory back to the pool; size ignored here
    cyg_bool free( cyg_uint8 *p, cyg_int32 size );

    // Get memory pool status
    // flags is a bitmask of requested fields to fill in. The flags are
    // defined in common.hxx
    void get_status( cyg_mempool_status_flag_t /* flags */,
                     Cyg_Mempool_Status & /* status */ );

};

#include <cyg/memalloc/mfiximpl.inl>

// -------------------------------------------------------------------------
#endif // ifndef CYGONCE_MEMALLOC_MFIXIMPL_HXX
// EOF mfiximpl.hxx