memory.c

类PASCAL语言的编译器,LINUX环境的,我没试过是否正确.

#ifdef RCS
static char rcsid[]="$Id: memory.c,v 1.2 1994/01/24 09:36:46 start Exp $";
#endif
/******************************************************************************
 *                               FREXXWARE
 * ----------------------------------------------------------------------------
 *
 * Project: Frexx C Preprocessor
 * $Source: /home/user/start/cpp/RCS/memory.c,v $
 * $Revision: 1.2 $
 * $Date: 1994/01/24 09:36:46 $
 * $Author: start $
 * $State: Exp $
 * $Locker:  $
 *
 * ----------------------------------------------------------------------------
 * $Log: memory.c,v $
 * Revision 1.2  1994/01/24  09:36:46  start
 * Made it run with OS9 properly.
 *
 * Revision 1.1  1993/11/03  09:13:08  start
 * Initial revision
 *
 *
 *****************************************************************************/

#include <string.h>
#include <stdlib.h>
#if defined(OS9)
#include <types.h>
#elif defined(UNIX)
#include <sys/types.h>
#elif defined(AMIGA)
#include <exec/types.h>
#include <proto/exec.h>
#endif

#include <stdio.h>

#include "memory.h"
#ifdef DEBUG
int mem;
int maxmem;
int malloc_count=0;
#endif

/*
 * We have two mallockey pointers because we have two different kinds of
 * Malloc()s! One for each execution and one for each fplInit().
 */
static struct MemInfo *MallocKey=NULL;

void *Realloc(void *ptr, int size)
{
  struct MemInfo *point;
  void *new;
  /* `point' points to the MemInfo structure: */
  point=(struct MemInfo *)((char *)ptr-sizeof(struct MemInfo));
 
  if(size<=point->size)
    /*
     * To increase performance, don't care about reallocing
     * to smaller sizes!
     */
    return(ptr);
  new=Malloc(size); /* allocate new storage */
  if(!new)
    return(NULL); /* fail! */
  
  memcpy(new, ptr, point->size); /* copy contents */

  Free(ptr); /* free old area */

  return(new); /* return new pointer */
}


void *Malloc(int size)
{
  char *alloc;
  struct MemInfo *point;

#ifdef DEBUG
  size+=MEMORY_COOKIE; /* add extra bytes after the block! */
#endif

#ifdef AMIGA
  alloc=(char *)AllocMem(size+sizeof(struct MemInfo), 0L);
#elif defined(UNIX)
  alloc=(char *)malloc(size+sizeof(struct MemInfo));
#endif

  if(!alloc)
    return(NULL);

  point=(struct MemInfo *)alloc;
  point->prev=MallocKey;	 /* previous */
  point->next=NULL;		 /* next */
  point->size=size;		 /* size */
#ifdef DEBUG
  malloc_count++;
  mem+=size+sizeof(struct MemInfo);
  if(mem>maxmem)
    maxmem=mem;

  memset((void *)((char *)point+sizeof(struct MemInfo)), 0xbb, size);
#endif
  if(MallocKey)
    point->prev->next=point;

  MallocKey = (void *)point;

  alloc = ((char *)point+sizeof(struct MemInfo));
  return ((void *)alloc);
}

void Free(void *ptr)
{
  struct MemInfo *point;
  /* `point' points to the MemInfo structure: */
  point=(struct MemInfo *)((char *)ptr-sizeof(struct MemInfo));

  if(MallocKey==point) {
    /* if this is the last Malloc, set `last' to `prev' */
    MallocKey=point->prev;
    if(MallocKey)
      MallocKey->next=NULL;
  } else {
    /* point the previous' `next' to our `next', and our next `previous'
       to our `previous'. Unlink us from the chain */
    if(point->prev)
      /* only if we aren't the _first_ Malloc() ! */
      point->prev->next=point->next;
    if(point->next)
      /* only if there is a next! */
      point->next->prev=point->prev;
  }
#ifdef DEBUG
  mem-=point->size+sizeof(struct MemInfo);

  CheckMem(ptr);
#endif

#ifdef AMIGA  
  FreeMem(point, point->size+sizeof(struct MemInfo));
#elif UNIX
  free(point);
#endif
}

#ifdef DEBUG
void CheckMem(void *ptr)
{
  int i;
  int b=0;
  struct MemInfo *point;
  /* `point' points to the MemInfo structure: */
  point=(struct MemInfo *)((char *)ptr-sizeof(struct MemInfo));
  for(i=0;i<MEMORY_COOKIE; i++)
    if(*((unsigned char *)point+sizeof(struct MemInfo)+i+point->size-MEMORY_COOKIE)!= 0xbb)
      b++;

  if(b) {
#if defined(UNIX)
    fprintf(stderr, "Memory violation: malloc(%d) was abused %d bytes!\n",
	    point->size-MEMORY_COOKIE-sizeof(struct MemInfo), b);
#elif defined(AMIGA)
    /* ERROR */;
#endif
  }
}
#endif

void FreeAll(void)
{
  struct MemInfo *point;
  void *prev;

  if(!MallocKey)
    return;
  do {
    point=MallocKey;
    /* `point' points to the MemInfo structure! */

    prev=(void *)point->prev;

#ifdef DEBUG
    mem-=point->size+sizeof(struct MemInfo);
#endif
#ifdef AMIGA
    FreeMem(MallocKey, point->size+sizeof(struct MemInfo));
#elif UNIX
    free((char *)MallocKey);
#endif
  } while(MallocKey=prev);
}