java.util.concurrent.atomic.AtomicInteger#lazySet()源码实例Demo

/**
 * get returns the last value lazySet in same thread
 */
public void testGetLazySet() {
    AtomicInteger ai = new AtomicInteger(1);
    assertEquals(1, ai.get());
    ai.lazySet(2);
    assertEquals(2, ai.get());
    ai.lazySet(-3);
    assertEquals(-3, ai.get());
}
 

/**
 * get returns the last value lazySet in same thread
 */
public void testGetLazySet() {
    AtomicInteger ai = new AtomicInteger(1);
    assertEquals(1, ai.get());
    ai.lazySet(2);
    assertEquals(2, ai.get());
    ai.lazySet(-3);
    assertEquals(-3, ai.get());
}
 

@Test
public void testAtomic() {
    AtomicInteger atomicInteger = new AtomicInteger(10);

    Assertions.assertThat(atomicInteger.decrementAndGet()).isEqualTo(9); // first decrement and then get
    Assertions.assertThat(atomicInteger.getAndDecrement()).isEqualTo(9); // first get and then decrement
    Assertions.assertThat(atomicInteger.incrementAndGet()).isEqualTo(9); // first increment and then get
    Assertions.assertThat(atomicInteger.getAndIncrement()).isEqualTo(9); // first get and then increment
    Assertions.assertThat(atomicInteger.get()).isEqualTo(10); // just get
    atomicInteger.set(12); // just set
    Assertions.assertThat(atomicInteger.getAndSet(11)).isEqualTo(12); // first get and then set
    Assertions.assertThat(atomicInteger.floatValue()).isEqualTo(11); // is equal
    Assertions.assertThat(atomicInteger.accumulateAndGet(50, (x, y) -> 2 * x + y)).isEqualTo(72);
    // IntBinaryOperator (x, y) -> z . Two times value inside 11 + supplied 50
    atomicInteger.set(5);
    Assertions.assertThat(atomicInteger.updateAndGet(x -> x * 3)).isEqualTo(15);
    // IntUnaryOperator x -> y . Three times value inside 5
    Assertions.assertThat(atomicInteger.addAndGet(6)).isEqualTo(21); // add and get

    atomicInteger.set(5); // initialize
    Assertions.assertThat(atomicInteger.compareAndSet(6, 10)).isFalse(); // will not update 6 != 5
    Assertions.assertThat(atomicInteger.compareAndSet(5, 11)).isTrue(); // will update case prev is 5
    Assertions.assertThat(atomicInteger.weakCompareAndSet(11, 12)).isTrue();
    // ! implementation is same as compareAndSet
    atomicInteger.lazySet(10);
    Assertions.assertThat(atomicInteger.get()).isEqualTo(10);

    AtomicBoolean atomicBoolean = new AtomicBoolean(); // default value=false, getAndSet, [weak]compareAndSet/ [lazy]set
    Assertions.assertThat(atomicBoolean.get()).isFalse();

    AtomicLong atomicLong = new AtomicLong(); // default value=0
    //

    AtomicReference<String> reference = new AtomicReference<>("hello");
}
 

public void sendTrain(final int trainNo) {
    final AtomicInteger stationIndex = train[trainNo].stationIndex;
    stationIndex.lazySet(stationIndex.get() + 1);
}