mempolt2.hxx

eCos操作系统源码

#ifndef CYGONCE_MEMALLOC_MEMPOLT2_HXX
#define CYGONCE_MEMALLOC_MEMPOLT2_HXX

//==========================================================================
//
//      mempolt2.hxx
//
//      Mempolt2 (Memory pool template) 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 Mempolt2 class interface
// Description:  The class defined here provides the APIs for thread-safe,
//               kernel-savvy memory managers; make a class with the
//               underlying allocator as the template parameter.
// Usage:        #include <cyg/memalloc/mempolt2.hxx>
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================

// It is assumed that implementations using this file have already mandated
// that the kernel is present. So we just go ahead and use it

#include <pkgconf/memalloc.h>
#include <cyg/kernel/ktypes.h>
#include <cyg/infra/cyg_ass.h>         // assertion macros
#include <cyg/kernel/thread.hxx>
#include <cyg/memalloc/common.hxx>     // Common memory allocator infra

template <class T>
class Cyg_Mempolt2
{
private:
    T pool;                             // underlying memory manager
    Cyg_ThreadQueue queue;              // queue of waiting threads

    class Mempolt2WaitInfo {
    private:
        Mempolt2WaitInfo() {}
    public:
        cyg_int32 size;
        cyg_uint8 *addr;
        Mempolt2WaitInfo( cyg_int32 allocsize )
        { size = allocsize; addr = 0; }
    };

public:

    Cyg_Mempolt2(
        cyg_uint8 *base,
        cyg_int32 size,
        CYG_ADDRWORD arg_thru );        // Constructor
    ~Cyg_Mempolt2();                    // Destructor
        
    // get some memory; wait if none available; return NULL if failed
    // due to interrupt
    cyg_uint8 *alloc( cyg_int32 size );
    
#ifdef CYGFUN_KERNEL_THREADS_TIMER
    // get some memory with a timeout; return NULL if failed
    // due to interrupt or timeout
    cyg_uint8 *alloc( cyg_int32 size, cyg_tick_count abs_timeout );
#endif

    // get some memory, return NULL if none available
    cyg_uint8 *try_alloc( cyg_int32 size );
    
    // resize existing allocation, if oldsize is non-NULL, previous
    // allocation size is placed into it. If previous size not available,
    // it is set to 0. NB previous allocation size may have been rounded up.
    // Occasionally the allocation can be adjusted *backwards* as well as,
    // or instead of forwards, therefore the address of the resized
    // allocation is returned, or NULL if no resizing was possible.
    // Note that this differs from ::realloc() in that no attempt is
    // made to call malloc() if resizing is not possible - that is left
    // to higher layers. The data is copied from old to new though.
    // The effects of alloc_ptr==NULL or newsize==0 are undefined
    cyg_uint8 *
    resize_alloc( cyg_uint8 *alloc_ptr, cyg_int32 newsize,
                  cyg_int32 *oldsize );

    // free the memory back to the pool
    // returns true on success
    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 );

    CYGDBG_DEFINE_CHECK_THIS
    
};

#include <cyg/memalloc/mempolt2.inl>

// -------------------------------------------------------------------------
#endif // ifndef CYGONCE_MEMALLOC_MEMPOLT2_HXX
// EOF mempolt2.hxx