/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <bin.h> enum{	StructAlign = sizeof(union {vlong vl; double d; ulong p; void *v;				struct{vlong v;}vs; struct{double d;}ds; struct{ulong p;}ss; struct{void *v;}xs;})}; enum{	BinSize	= 8*1024}; struct Bin{	Bin	*next;	ulong	total;			/* total bytes allocated in can->next */	uintptr	pos;	uintptr	end;	uintptr	v;			/* last value allocated */	uchar	body[BinSize];}; /* * allocator which allows an entire set to be freed at one time */static Bin*mkbin(Bin *bin, ulong size){	Bin *b; 	size = ((size << 1) + (BinSize - 1)) & ~(BinSize - 1);	b = malloc(sizeof(Bin) + size - BinSize);	if(b == nil)		return nil;	b->next = bin;	b->total = 0;	if(bin != nil)		b->total = bin->total + bin->pos - (uintptr)bin->body;	b->pos = (uintptr)b->body;	b->end = b->pos + size;	return b;} void*binalloc(Bin **bin, ulong size, int zero){	Bin *b;	uintptr p; 	if(size == 0)		size = 1;	b = *bin;	if(b == nil){		b = mkbin(nil, size);		if(b == nil)			return nil;		*bin = b;	}	p = b->pos;	p = (p + (StructAlign - 1)) & ~(StructAlign - 1);	if(p + size > b->end){		b = mkbin(b, size);		if(b == nil)			return nil;		*bin = b;		p = b->pos;	}	b->pos = p + size;	b->v = p;	if(zero)		memset((void*)p, 0, size);	return (void*)p;} void*bingrow(Bin **bin, void *op, ulong osize, ulong size, int zero){	Bin *b;	void *np;	uintptr p; 	p = (uintptr)op;	b = *bin;	if(b != nil && p == b->v && p + size <= b->end){		b->pos = p + size;		if(zero)			memset((char*)p + osize, 0, size - osize);		return op;	}	np = binalloc(bin, size, zero);	if(np == nil)		return nil;	memmove(np, op, osize);	return np;} voidbinfree(Bin **bin){	Bin *last; 	while(*bin != nil){		last = *bin;		*bin = (*bin)->next;		last->pos = (uintptr)last->body;		free(last);	}}