1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
class Simulator {
static void simulateWork() {
try {
Thread.sleep(3); // simulates work being done
} catch (InterruptedException ex) {
System.out.println(ex);
}
}
}
class Shared {
static final Map<String, int[]> cache = new HashMap<>();
}
class Producer {
protected int produce() {
Simulator.simulateWork();
return 1;
}
}
class Writer extends Producer implements Runnable {
public void run() {
int[] referenceToValue = Shared.cache.get("key");
for (int i = 0; i < referenceToValue.length; i++) {
// Update value in-place; sum will add up to length
referenceToValue[i] = produce();
}
}
}
class Consumer {
protected void consume(int[] value) {
int sum = Arrays.stream(value).sum();
if (sum != 0 && sum != value.length) {
throw new IllegalStateException("Partial sum: " + sum);
}
Simulator.simulateWork();
}
}
class Reader extends Consumer implements Runnable {
public void run() {
consume(Shared.cache.get("key"));
Press desired key combination and then press ENTER.
