getprio.c

来自「TCP-IP红宝书源代码」· C语言 代码 · 共 25 行

/* getprio.c - getprio */

#include <conf.h>
#include <kernel.h>
#include <proc.h>

/*------------------------------------------------------------------------
 * getprio -- return the scheduling priority of a given process
 *------------------------------------------------------------------------
 */
SYSCALL getprio(pid)
	int	pid;
{
	STATWORD ps;    
	struct	pentry	*pptr;

	disable(ps);
	if (isbadpid(pid) || (pptr = &proctab[pid])->pstate == PRFREE) {
		restore(ps);
		return(SYSERR);
	}
	restore(ps);
	return(pptr->pprio);
}