Logo Search packages:      
Sourcecode: ksh version File versions  Download package

vmalloc.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2010 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * standalone mini vmalloc implementation
 * no resize, no free, no disciplines, no methods
 */

#include <ast.h>
#include <vmalloc.h>

Vmalloc_t*  Vmregion;

Vmalloc_t*
_vm_open(void)
{
      Vmalloc_t*  vp;

      if (vp = newof(0, Vmalloc_t, 1, 0))
      {
            vp->current = &vp->base;
            vp->data = vp->current->data;
            vp->size = sizeof(vp->current->data);
      }
      return vp;
}

int
_vm_close(register Vmalloc_t* vp)
{
      register Vmchunk_t*     cp;
      register Vmchunk_t*     np;

      if (!vp)
            return -1;
      np = vp->base.next;
      while (cp = np)
      {
            np = cp->next;
            free(cp);
      }
      free(vp);
      return 0;
}

void*
_vm_resize(register Vmalloc_t* vp, void* o, unsigned long size)
{
      char*       p;
      unsigned long     n;
      unsigned long     z;

      z = vp->last;
      vp->last = size;
      if (o && size < z)
            return o;
      if ((o ? (size - z) : size) > vp->size)
      {
            n = (size > sizeof(vp->current->data)) ? (size - sizeof(vp->current->data)) : 0;
            if (!(vp->current->next = newof(0, Vmchunk_t, 1, n)))
                  return 0;
            vp->current = vp->current->next;
            vp->data = vp->current->data;
            vp->size = n ? 0 : sizeof(vp->current->data);
            if (o)
            {
                  memcpy(vp->data, o, z);
                  o = (void*)vp->data;
            }
      }
      else if (o)
            size -= z;
      p = vp->data;
      size = roundof(size, VM_ALIGN);
      if (size >= vp->size)
            vp->size = 0;
      else
      {
            vp->size -= size;
            vp->data += size;
      }
      return p;
}

Generated by  Doxygen 1.6.0   Back to index