alloc.c

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#ifndef __SYSTEM
#include "routix/system.h"
#endif
#include <routix/kstdio.h>
#include "routix/paging.h"
#include "routix/kalloc.h"
#include "routix/debug.h"

volatile int num_mallocs = 0;
volatile int num_frees = 0;

unsigned int umalloc_alloc = 0, umalloc_free = 0;
unsigned int file_alloc = 0, file_free = 0;

void free (void *);

addr_t *_inicio,*_fin,*_sp;

/* Funciones relacionadas con malloc */

typedef long Align;

typedef union header {
    struct {
        union header *ptr;
        unsigned size;
    } s;
    Align x;
} Header;

//typedef union header Header;

static Header base;
static Header *freep=NULL;

Header *morecore(void);

void *malloc (unsigned nbytes)
{
        cli();
    Header *p, *prevp;
    unsigned nunits;
    nunits = (nbytes + sizeof(Header)-1) / sizeof(Header) +1;
    if ((prevp = freep)==NULL)     {
                base.s.ptr = freep = prevp = &base;
                base.s.size = 0;
    }

    for ( p=prevp->s.ptr ;   ;  prevp=p , p=p->s.ptr)     {
        if (p->s.size >= nunits) {
                    if (p->s.size == nunits)
                                prevp->s.ptr = p->s.ptr;
                    else        {
                                p->s.size -= nunits;
                                p += p->s.size;
                                p->s.size = nunits;
                }
                    freep = prevp;
/*TEMP*/        num_mallocs++;
                        sti();
                    return (p+1);
                }
                else if (p==freep) {
                if ( (p = morecore()) == NULL ) {
                        sti();
                                return NULL;
                        }
                }
    }
        sti();
        return NULL;
}



volatile word morecores=0;

Header *morecore(void)
{
    Header *up;

    up = (Header *) kmalloc_page();
    if (up == NULL)     {
        return NULL;
    }

        morecores++;
    
    up->s.size= PAGINA_SIZE / sizeof(Header);
    free ( (void *) (up+1));
    return freep;
}



void free (void *ap)
{
        cli();
    Header *bp, *p;

    bp = (Header *) ap - 1;
    for (p=freep; ! (bp > p && bp < p->s.ptr) ; p=p->s.ptr)
        if ( (p >= p->s.ptr)  &&  (bp > p || bp < p->s.ptr))
                    break;
    if ( (bp + bp->s.size) == p->s.ptr) {
                bp->s.size += p->s.ptr->s.size;
                bp->s.ptr = p->s.ptr->s.ptr;
    }
    else bp->s.ptr = p->s.ptr;

    if ( (p+p->s.size) == bp)   {
                p->s.size += bp->s.size;
                p->s.ptr = bp->s.ptr;
    }
    else p->s.ptr = bp;

    freep = p;    

        num_frees++;
        sti();
}

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