ms_wrklst.c

一个用在mips体系结构中的操作系统

/*
 * Copyright (C) 1996-1998 by the Board of Trustees
 *    of Leland Stanford Junior University.
 * 
 * This file is part of the SimOS distribution. 
 * See LICENSE file for terms of the license. 
 *
 */


	/*
	 *  ms_wrklst.c  -  Implement the worklist mechanism for the
	 *		    simulator.
	 *
	 *	The worklist mechanism is designed to handle instructions
	 *	that take multiple cycles to complete, such as floating
	 *	point operations, or cache accesses.  These instructions
	 *	are handled by locking their destination register, and then
	 *	scheduling their completion for the appropriate cycle.
	 *
	 *	Jim Bennett
	 *	1993, 1994
	 */

#include <stdlib.h>
#include "ms.h"

#ifndef INLINE

void Add_to_worklist(struct s_cpu_state *st, int inc,
		void (*func)(void *st, void *a2),
		void *argument2)
	{
	WorkList *wd_w, *wd_wlp;
	int	wd_c;

	wd_w = st->free_head;
	if (wd_w == NULL)
		{
		fprintf (stderr, "Out of work items!!\r\n");
		ms_break (st, NULL, "ERR");
		}
	st->free_head = wd_w->next;
	wd_c = st->work_cycle+(inc);
	wd_wlp = st->work_tail;
	if (wd_wlp == NULL)
		{
		wd_w->next = NULL;
		st->work_head = wd_w;
		st->work_tail = wd_w;
		}
	else if (wd_c < wd_wlp->cycle)
		{
		wd_wlp = st->work_head;
		if (wd_c < wd_wlp->cycle)
			{
			wd_w->next = wd_wlp;
			st->work_head = wd_w;
			}
		else
			{
			for (; wd_wlp->next->cycle < wd_c;
					wd_wlp = wd_wlp->next);
			wd_w->next = wd_wlp->next;
			wd_wlp->next = wd_w;
			}
		}
	else
		{
		wd_w->next = NULL;
		wd_wlp->next = wd_w;
		st->work_tail = wd_w;
		}
	wd_w->cycle = wd_c;
	wd_w->f = func;
	wd_w->arg2 = argument2;
	}
#endif