static const char *rcsid = "$Id: sieve.c 6 2007-01-22 00:45:22Z drhanson $" "\n$Id: sieve.c 6 2007-01-22 00:45:22Z drhanson $";#include <stdio.h>#include <stdlib.h>#include "assert.h"#include "fmt.h"#include "thread.h"#include "chan.h"struct args {	Chan_T c;	int n, last;};int source(void *cl) {	struct args *p = cl;	int i = 2;	if (Chan_send(p->c, &i, sizeof i))		for (i = 3; Chan_send(p->c, &i, sizeof i); )			i += 2;	return EXIT_SUCCESS;}void filter(int primes[], Chan_T input, Chan_T output) {	int j, x;	for (;;) {		Chan_receive(input, &x, sizeof x);		for (j = 0; primes[j] != 0 && x%primes[j] != 0; j++)			;		if (primes[j] == 0)			 if (Chan_send(output, &x, sizeof x) == 0)				break;	}	Chan_receive(input, &x, 0);}int sink(void *cl) {	struct args *p = cl;	Chan_T input = p->c;	int i = 0, j, x, primes[256];	primes[0] = 0;	for (;;) {		Chan_receive(input, &x, sizeof x); 		for (j = 0; primes[j] != 0 && x%primes[j] != 0; j++)			;		if (primes[j] == 0) {			if (x > p->last)				break;			Fmt_print(" %d", x);			primes[i++] = x;			primes[i] = 0;			if (i == p->n)				{					p->c = Chan_new();					Thread_new(sink, p, sizeof *p, NULL);					filter(primes, input, p->c);					return EXIT_SUCCESS;				}		}	}	Fmt_print("\n");	Chan_receive(input, &x, 0); 	return EXIT_SUCCESS;}int main(int argc, char *argv[]) {	struct args args;	Thread_init(1, NULL);	args.c = Chan_new();	Thread_new(source, &args, sizeof args, NULL);	args.n    = argc > 2 ? atoi(argv[2]) : 5;	args.last = argc > 1 ? atoi(argv[1]) : 1000;	Thread_new(sink,   &args, sizeof args, NULL);	Thread_exit(EXIT_SUCCESS);	return EXIT_SUCCESS;}