/*  * 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 <tos.h> static uvlong order = 0x0001020304050607ULL; static voidbe2vlong(vlong *to, uchar *f){	uchar *t, *o;	int i; 	t = (uchar*)to;	o = (uchar*)&order;	for(i = 0; i < sizeof order; i++)		t[o[i]] = f[i];} static int fd = -1;static struct {	int	pid;	int	fd;} fds[64]; vlongnsec(void){	uchar b[8];	vlong t;	int pid, i, f, tries; 	/*	 * Threaded programs may have multiple procs	 * with different fd tables, so we may need to open	 * /dev/bintime on a per-pid basis	 */ 	/* First, look if we've opened it for this particular pid */	if((pid = _tos->pid) == 0)		/* 9vx bug, perhaps? */		_tos->pid = pid = getpid();	do{		f = -1;		for(i = 0; i < nelem(fds); i++)			if(fds[i].pid == pid){				f = fds[i].fd;				break;			}		tries = 0;		if(f < 0){			/* If it's not open for this pid, try the global pid */			if(fd >= 0)				f = fd;			else{				/* must open */				if((f = open("/dev/bintime", OREAD|OCEXEC)) < 0)					return 0;				fd = f;				for(i = 0; i < nelem(fds); i++)					if(fds[i].pid == pid || fds[i].pid == 0){						fds[i].pid = pid;						fds[i].fd = f;						break;					}			}		}		if(pread(f, b, sizeof b, 0) == sizeof b){			be2vlong(&t, b);			return t;		}		close(f);		if(i < nelem(fds))			fds[i].fd = -1;	}while(tries++ == 0);	/* retry once */	USED(tries);	return 0;}