dlmalloc.hxx

eCos操作系统源码

#ifndef CYGONCE_MEMALLOC_DLMALLOC_HXX
#define CYGONCE_MEMALLOC_DLMALLOC_HXX

//==========================================================================
//
//      dlmalloc.hxx
//
//      Interface to the port of Doug Lea's malloc implementation
//
//==========================================================================
//####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):    jlarmour
// Contributors: 
// Date:         2000-06-18
// Purpose:      Define standard interface to Doug Lea's malloc implementation
// Description:  Doug Lea's malloc has been ported to eCos. This file provides
//               the interface between the implementation and the standard
//               memory allocator interface required by eCos
// Usage:        #include <cyg/memalloc/dlmalloc.hxx>
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================

// CONFIGURATION

#include <pkgconf/memalloc.h>

#ifdef CYGIMP_MEMALLOC_ALLOCATOR_DLMALLOC_THREADAWARE
# include <pkgconf/system.h>
# ifdef CYGPKG_KERNEL
#  include <pkgconf/kernel.h>
# endif
#endif

// when used as an implementation for malloc, we need the following
// to let the system know the name of the class
#define CYGCLS_MEMALLOC_MALLOC_IMPL Cyg_Mempool_dlmalloc

// if the implementation is all that's required, don't output anything else
#ifndef __MALLOC_IMPL_WANTED

// INCLUDES

#include <stddef.h>                      // size_t, ptrdiff_t
#include <cyg/infra/cyg_type.h>          // types
#ifdef CYGIMP_MEMALLOC_ALLOCATOR_DLMALLOC_THREADAWARE
# include <cyg/memalloc/mempolt2.hxx>    // kernel safe mempool template
#endif
#include <cyg/memalloc/dlmallocimpl.hxx> // dlmalloc implementation
#include <cyg/memalloc/common.hxx>       // Common memory allocator infra
#ifdef CYGFUN_KERNEL_THREADS_TIMER
# include <cyg/kernel/ktypes.h>          // cyg_tick_count
#endif


// TYPE DEFINITIONS


class Cyg_Mempool_dlmalloc
{
protected:
#ifdef CYGIMP_MEMALLOC_ALLOCATOR_DLMALLOC_THREADAWARE
    Cyg_Mempolt2<Cyg_Mempool_dlmalloc_Implementation> mypool;
#else
    Cyg_Mempool_dlmalloc_Implementation mypool;
#endif


public:
    // 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.
    Cyg_Mempool_dlmalloc( cyg_uint8 *base, cyg_int32 size, 
                          CYG_ADDRWORD argthru=0 )
        : mypool( base, size, argthru ) {}

    // Destructor
    ~Cyg_Mempool_dlmalloc() {}

    // get some memory; wait if none available
    // if we aren't configured to be thread-aware this is irrelevant
#ifdef CYGIMP_MEMALLOC_ALLOCATOR_DLMALLOC_THREADAWARE
    cyg_uint8 *
    alloc( cyg_int32 size ) { return mypool.alloc( size ); }
    
# ifdef CYGFUN_KERNEL_THREADS_TIMER
    // get some memory with a timeout
    cyg_uint8 *
    alloc( cyg_int32 size, cyg_tick_count delay_timeout ) {
        return mypool.alloc( size, delay_timeout );
    }
# endif
#endif

    // get some memory, return NULL if none available
    cyg_uint8 *
    try_alloc( cyg_int32 size ) { return mypool.try_alloc( 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 ) { 
        return mypool.resize_alloc( alloc_ptr, newsize, oldsize);
    }

    // free the memory back to the pool
    // returns true on success
    cyg_bool
    free( cyg_uint8 *ptr, cyg_int32 size=0 ) { return mypool.free(ptr, 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 ) {
        // set to 0 - if there's anything really waiting, it will be set to
        // 1 later
        status.waiting = 0;
        mypool.get_status( flags, status );
    }
};

#endif // ifndef __MALLOC_IMPL_WANTED

#endif // ifndef CYGONCE_MEMALLOC_DLMALLOC_HXX
// EOF dlmalloc.hxx