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