// has methods for priority and without priority

import java.util.*;

import Scheduler.Scheduler;
import Scheduler.Guard;
import Scheduler.Process;

public class Readers_Writers {
	public static void main(String[] args) {

		RWController rwc = new RWController();
		Database d = new Database();

		Reader r1 = new Reader();
		Reader r2 = new Reader();
		Reader r3 = new Reader();
		Reader r4 = new Reader();
		Reader r5 = new Reader();

		Writer w1 = new Writer();
		Writer w2 = new Writer();
		Writer w3 = new Writer();
		Writer w4 = new Writer();
		Writer w5 = new Writer();

		Process[] arr = { rwc, d, r1, r2, r3, r4, r5, w1, w2, w3, w4, w5 };
		Scheduler s = new Scheduler(arr, true);
		s.start();
	}
}

class Database extends Process {

	private int data = 0;
	String state;

	public void run() {
		while (true) {

			send_or_receive_data("read", data, "write");
			state = chosen;
			if (chosen.equals("write")) {
				data = data + (int) get_data();
				System.out.println("Database write = " + data + "\n");
			}
		}
	}

}

// --------------Reader --------------------

class Reader extends Process {

	public void run() {
		for (int i = 0; i < 5; i++) {
			;
			send("request_read");
			receive("read");
			read();
			send("done_read");
		}
	}

	void read() {
		System.out.println("Database read = " + (int) get_data() + "\n");
	}
}

// ---------------- Writer  -------------------------------------

class Writer extends Process {

	public void run() {
		Random r = new Random();
		for (int i = 1; i < 6; i++) {
			try {
				Thread.sleep(250);
			} catch (Exception e) {
			}
			send("request_write");
			write(i);
			send("done_write");
		}
	}

	void write(int i) {
		send_data("write", i * 1000);
	}
}

// --------------- Readers-Writers Controller -------------------

class RWController extends Process {
	private String state;
	private int r = 0, w = 0, ww = 0, wr = 0;

	public void run() {
		schedule_without_priority();
	}

	public void schedule_without_priority() {
		while (true) {
			state = "init";
			receive("request_read", "request_write");
			state = chosen;
			switch (chosen) {
			case ("request_read"):
				r = 1;
				while (r != 0) {
					receive("request_read", "done_read");
					state = chosen;
					switch (chosen) {
					case ("request_read"):
						r++;
						break;
					case ("done_read"):
						r--;
						break;
					}
				}
				break;
			case ("request_write"):
				w = 1;
				receive("done_write");
				w = 0;
				state = "done_write";
			}
		}
	}

	int ww() {
		int t = num_waiting("send", "request_write");
		if (t != ww)
			ww = t;
		return ww;
	}

	int wr() {
		int t = num_waiting("send", "request_read");
		if (t != wr)
			wr = t;
		return wr;
	}