public class LongAdderTest {
public static void main(String[] args) {
System.out.println("LongAdder ...........");
for (int i = 0; i < 5; i++) {
addFunc(() -> new LongAdder(), adder -> adder.increment());
}
System.out.println("AtomicLong ...........");
for (int i = 0; i < 5; i++) {
addFunc(() -> new AtomicLong(), adder -> adder.getAndIncrement());
}
}
private static <T> void addFunc(Supplier<T> adderSupplier, Consumer<T> action) {
T adder = adderSupplier.get();
long start = System.nanoTime();
List<Thread> ts = new ArrayList<>();
// 40个线程,每人累加 50 万
for (int i = 0; i < 40; i++) {
ts.add(new Thread(() -> {
for (int j = 0; j < 500000; j++) {
action.accept(adder);
}
}));
}
ts.forEach(t -> t.start());
ts.forEach(t -> {
try {
t.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
});
long end = System.nanoTime();
System.out.println(adder + " cost:" + (end - start)/1000_000);
}
}