//bench/bw_svmsg.c
void
writer(int contfd, int msqid)
{
	int		ntowrite;

	for ( ; ; ) {
		Read(contfd, &ntowrite, sizeof(ntowrite));

		while (ntowrite > 0) {
			Msgsnd(msqid, buf, xfersize - sizeof(long), 0);
			ntowrite -= xfersize;
		}
	}
}

void
reader(int contfd, int msqid, int nbytes)
{
	ssize_t	n;

	Write(contfd, &nbytes, sizeof(nbytes));

	while ((nbytes > 0) &&
		   ( (n = Msgrcv(msqid, buf, xfersize - sizeof(long), 0, 0)) > 0)) {
		nbytes -= n + sizeof(long);
	}
}
