/*
* Copyright DataStax, Inc.
*
* Licensed 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
*
* http://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 com.datastax.oss.driver.internal.core.time;
import com.datastax.oss.driver.api.core.context.DriverContext;
import com.datastax.oss.driver.internal.core.context.InternalDriverContext;
import com.datastax.oss.driver.shaded.guava.common.annotations.VisibleForTesting;
import java.util.concurrent.atomic.AtomicLong;
import net.jcip.annotations.ThreadSafe;
A timestamp generator that guarantees monotonically increasing timestamps across all client
threads, and logs warnings when timestamps drift in the future.
To activate this generator, modify the advanced.timestamp-generator
section in the driver configuration, for example:
datastax-java-driver {
advanced.timestamp-generator {
class = AtomicTimestampGenerator
drift-warning {
threshold = 1 second
interval = 10 seconds
}
force-java-clock = false
}
}
See reference.conf
(in the manual or core driver JAR) for more details. /**
* A timestamp generator that guarantees monotonically increasing timestamps across all client
* threads, and logs warnings when timestamps drift in the future.
*
* <p>To activate this generator, modify the {@code advanced.timestamp-generator} section in the
* driver configuration, for example:
*
* <pre>
* datastax-java-driver {
* advanced.timestamp-generator {
* class = AtomicTimestampGenerator
* drift-warning {
* threshold = 1 second
* interval = 10 seconds
* }
* force-java-clock = false
* }
* }
* </pre>
*
* See {@code reference.conf} (in the manual or core driver JAR) for more details.
*/
@ThreadSafe
public class AtomicTimestampGenerator extends MonotonicTimestampGenerator {
private AtomicLong lastRef = new AtomicLong(0);
public AtomicTimestampGenerator(DriverContext context) {
super(context);
}
@VisibleForTesting
AtomicTimestampGenerator(Clock clock, InternalDriverContext context) {
super(clock, context);
}
@Override
public long next() {
while (true) {
long last = lastRef.get();
long next = computeNext(last);
if (lastRef.compareAndSet(last, next)) {
return next;
}
}
}
}