#include <u.h>#include <libc.h>#include <libg.h>#include <panel.h>#include "mothra.h" enum{	MAGIC		= 0xbada110c,	MAX2SIZE	= 32,	CUTOFF		= 12,}; typedef struct Bucket Bucket;struct Bucket{	int	size;	int	magic;	Bucket	*next;	int pad;	char	data[1];}; typedef struct Arena Arena;struct Arena{	int enter;	int exit;	Bucket	*btab[MAX2SIZE];	};static Arena arena; #define datoff		((int)((Bucket*)0)->data)#define nil		((void*)0) static void*nlmalloc(long size){	ulong next;	int pow, n;	Bucket *bp, *nbp; 	for(pow = 1; pow < MAX2SIZE; pow++) {		if(size <= (1<<pow))			goto good;	} 	return nil;good:	/* Allocate off this list */	bp = arena.btab[pow];	if(bp) {		arena.btab[pow] = bp->next; 		if(bp->magic != 0)			abort(); 		bp->magic = MAGIC;		return  bp->data;	}	size = sizeof(Bucket)+(1<<pow);	size += 7;	size &= ~7; 	if(pow < CUTOFF) {		n = (CUTOFF-pow)+2;		bp = sbrk(size*n);		if((int)bp < 0)			return nil; 		next = (ulong)bp+size;		nbp = (Bucket*)next;		arena.btab[pow] = nbp;		for(n -= 2; n; n--) {			next = (ulong)nbp+size;			nbp->next = (Bucket*)next;			nbp->size = pow;			nbp = nbp->next;		}		nbp->size = pow;	}	else {		bp = sbrk(size);		if((int)bp < 0)			return nil;	}			bp->size = pow;	bp->magic = MAGIC; 	return bp->data;}void mlock(void){	static int first = 1; 	if(first){		first=0;		switch(fork()){		case -1:			fprint(2, "malloc: can't make lock process!\n");			exits("no lock");		case 0:			for(;;){				rendezvous((ulong)&arena.enter, 1);				rendezvous((ulong)&arena.exit, 0);			}		}	}	do;while(rendezvous((ulong)&arena.enter, 0)!=1);}void munlock(void){	rendezvous((ulong)&arena.exit, 0);}void *malloc(long size){	void *v;	mlock();	v=nlmalloc(size);	munlock();	return v;}void*calloc(long n, long size){	void *p; 	n *= size;	p = malloc(n);	if(p)		memset(p, 0, n); 	return p;} static voidnlfree(void *ptr){	Bucket *bp, **l; 	if(ptr == nil)		return; 	/* Find the start of the structure */	bp = (Bucket*)((uint)ptr - datoff); 	if(bp->magic != MAGIC)		abort(); 	bp->magic = 0;	l = &arena.btab[bp->size];	bp->next = *l;	*l = bp;} voidfree(void *ptr){	mlock();	nlfree(ptr);	munlock();} static void*nlrealloc(void *ptr, long n){	void *new;	uint osize;	Bucket *bp; 	if(ptr == nil)		return nlmalloc(n); 	/* Find the start of the structure */	bp = (Bucket*)((uint)ptr - datoff); 	if(bp->magic != MAGIC)		abort(); 	/* enough space in this bucket */	osize = 1<<bp->size;	if(osize >= n && n > osize/2)		return ptr; 	new = nlmalloc(n);	if(new == nil)		return nil; 	memmove(new, ptr, osize < n ? osize : n);	nlfree(ptr); 	return new;} void *realloc(void *ptr, long size){	void *v;	mlock();	v=nlrealloc(ptr, size);	munlock();	return v;}