066d1e09a4
WHAT'S NEW with version 0.0.3:
- Fixed bug with sector sizes.
- Registers at program startup are now set correctly.
- Segment fixups for relocatable-segment internal entry points.
- Fixed bug in DOS PSP structure.
- Some resource loading is done.
- Added "return" ordinal type to build program.
- Added comment capability to build program.
93 lines
1.8 KiB
C
93 lines
1.8 KiB
C
static char RCSId[] = "$Id: heap.c,v 1.1 1993/06/29 15:55:18 root Exp $";
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static char Copyright[] = "Copyright Robert J. Amstadt, 1993";
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#include <stdio.h>
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#include <stdlib.h>
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#include "prototypes.h"
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typedef struct heap_mem_desc_s
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{
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struct heap_mem_desc_s *prev, *next;
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int length;
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} MDESC;
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MDESC *FreeList;
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/**********************************************************************
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* HEAP_LocalInit
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*/
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void
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HEAP_LocalInit(void *start, int length)
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{
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FreeList = (MDESC *) start;
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FreeList->prev = NULL;
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FreeList->next = NULL;
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FreeList->length = length - sizeof(MDESC);
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}
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/**********************************************************************
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* HEAP_LocalAlloc
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*/
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void *
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HEAP_LocalAlloc(int flags, int bytes)
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{
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MDESC *m, *m_new;
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#ifdef HEAP_DEBUG
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printf("LocalAlloc: flags %x, bytes %d, ", flags, bytes);
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#endif
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/*
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* Find free block big enough.
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*/
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for (m = FreeList; m != NULL; m = m->next)
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{
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if (m->length == bytes && m->length < bytes + 4 * sizeof(MDESC))
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{
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break;
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}
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else if (m->length > bytes)
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{
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m_new = m + (bytes / sizeof(MDESC)) + 2;
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if (m->prev == NULL)
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FreeList = m_new;
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else
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m->prev->next = m_new;
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if (m->next != NULL)
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m->next->prev = m_new;
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m_new->next = m->next;
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m_new->prev = m->prev;
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m_new->length = m->length - ((int) m_new - (int) m);
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m->length -= (m_new->length + sizeof(MDESC));
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#ifdef HEAP_DEBUG
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printf("Returning %x\n", (int) (m + 1));
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#endif
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return (void *) (m + 1);
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}
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}
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if (m != NULL)
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{
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if (m->prev == NULL)
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FreeList = m->next;
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else
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m->prev->next = m->next;
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if (m->next != NULL)
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m->next->prev = m->prev;
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#ifdef HEAP_DEBUG
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printf("Returning %x\n", (int) (m + 1));
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#endif
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return (void *) (m + 1);
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}
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#ifdef HEAP_DEBUG
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printf("Returning 0\n");
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#endif
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return 0;
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}
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