#include <u.h>
#include <libc.h>
#include <thread.h>

#include "girzu.h"

void
usage(void)
{
	fprint(2, "usage: %s\n", argv0);
	threadexitsall("usage");
}

WaitGroup wg;
Channel *data;
Channel *cancel;

void
eclose(Channel *c)
{
	assert(sendul(c, 0) == 1);
	assert(chanclose(c) >= 0);
}

void
proc(void*)
{
	ulong i;
	int rv;
	while((rv = recv(data, &i)) == 1){
		fprint(2, "proc: recv %lud\n", i);
		if(i == 5)
			eclose(cancel);
	}

	print("proc: exited rv=%d %d %d\n", rv, chanclosing(data), chanclosing(cancel));
	wgdone(&wg);
}

void
threadmain(int argc, char *argv[])
{
	ulong v;
	int rv;

	ARGBEGIN{
	default:
		usage();
	}ARGEND

	v = 0;

	data = chancreate(sizeof(ulong), 0);
	cancel = chancreate(sizeof(ulong), 0);

	Alt a[] = {
	[0]	{	data,	&v,		CHANSND	},
	[1]	{	cancel,	nil,	CHANRCV	},
	[2]	{	nil,	nil,	CHANEND	},
	};

	wginit(&wg, 1);

	threadcreate(proc, 0, 8192);

	for(;;){
		rv = alt(a);
		print("alt = %d\n", rv);
		switch(rv){
			case -1:
				sysfatal("alt: %r");
			case 0:
				v++;
				break;
			case 1:
				print("cancel %s\n", a[1].err);
				chanclose(data);
				a[0].op = CHANNOP;
				a[1].op = CHANNOP;
				a[2].op = CHANNOBLK;
				break;
			case 2:
				goto fin;
		}
	}
fin:

	wgwait(&wg);

	chanfree(data);
	chanfree(cancel);

	threadexitsall(nil);
}