Netty分布式高性能工具类同线程下回收对象解析

public static void main(String[] args){
    User user1 = RECYCLER.get();
    user1.recycle();
    User user2 = RECYCLER.get();
    user2.recycle();
    System.out.println(user1==user2);
}

static class User{
    private final Recycler.Handle<User> handle;
    public User(Recycler.Handle<User> handle){
        this.handle=handle;
    }
    public void recycle(){
        handle.recycle(this);
    }
}

public void recycle(Object object) {
    if (object != value) {
        throw new IllegalArgumentException("object does not belong to handle");
    }
    stack.push(this);
}

void push(DefaultHandle<?> item) {
    Thread currentThread = Thread.currentThread();
    if (thread == currentThread) {
        pushNow(item);
    } else {
        pushLater(item, currentThread);
    }
}

private void pushNow(DefaultHandle<?> item) {
    if ((item.recycleId | item.lastRecycledId) != 0) {
        throw new IllegalStateException("recycled already");
    }
    item.recycleId = item.lastRecycledId = OWN_THREAD_ID;
    int size = this.size;
    if (size >= maxCapacity || dropHandle(item)) {
        return;
    }
    if (size == elements.length) {
        elements = Arrays.copyOf(elements, min(size << 1, maxCapacity));
    }
    elements[size] = item;
    this.size = size + 1;
}

boolean dropHandle(DefaultHandle<?> handle) {
    if (!handle.hasBeenRecycled) {
        if ((++handleRecycleCount & ratioMask) != 0) {
            return true;
        }
        handle.hasBeenRecycled = true;
    }
    return false;
}