io.netty.resolver.dns.RotationalDnsServerAddresses Maven / Gradle / Ivy
/*
* Copyright 2015 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.resolver.dns;
import java.net.InetSocketAddress;
import java.util.List;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
final class RotationalDnsServerAddresses extends DefaultDnsServerAddresses {
private static final AtomicIntegerFieldUpdater startIdxUpdater =
AtomicIntegerFieldUpdater.newUpdater(RotationalDnsServerAddresses.class, "startIdx");
@SuppressWarnings("UnusedDeclaration")
private volatile int startIdx;
RotationalDnsServerAddresses(List addresses) {
super("rotational", addresses);
}
@Override
public DnsServerAddressStream stream() {
for (;;) {
int curStartIdx = startIdx;
int nextStartIdx = curStartIdx + 1;
if (nextStartIdx >= addresses.size()) {
nextStartIdx = 0;
}
if (startIdxUpdater.compareAndSet(this, curStartIdx, nextStartIdx)) {
return new SequentialDnsServerAddressStream(addresses, curStartIdx);
}
}
}
}