Example of StamedLock usage

CachingSupplier.java

import java.time.Duration;
import java.util.concurrent.locks.StampedLock;
import java.util.function.Supplier;

public class CachingSupplier<T> implements Supplier<T> {

    private final Supplier<T> targetSupplier;
    private final long cachingDurationNanos;
    private final StampedLock stampedLock = new StampedLock();

    private T cachedValue;
    private long lastSnapshotNanoTime;
    private boolean initialized;

    public CachingSupplier(Duration cachingDuration, Supplier<T> targetSupplier) {
        this.targetSupplier = targetSupplier;
        this.cachingDurationNanos = cachingDuration.toNanos();
    }

    @Override
    final public T get() {
        long nanoTime = System.nanoTime();

        long stamp = stampedLock.tryOptimisticRead();

        long lastSnapshotNanoTime = this.lastSnapshotNanoTime;
        T cachedValue = this.cachedValue;
        boolean initialized = this.initialized;

        if (stampedLock.validate(stamp)) {
            if (initialized && nanoTime - lastSnapshotNanoTime <= cachingDurationNanos) {
                // основной выигрышь сдесь, мы прошли по всем веткам не выполнив не одной записи
                return cachedValue;
            }
        }

        stamp = stampedLock.writeLock();
        try {
            nanoTime = System.nanoTime();

            if (this.initialized && nanoTime - this.lastSnapshotNanoTime <= cachingDurationNanos) {
                return this.cachedValue;
            }

            this.cachedValue = targetSupplier.get();
            this.initialized = true;
            this.lastSnapshotNanoTime = nanoTime;
            return this.cachedValue;
        } finally {
            stampedLock.unlockWrite(stamp);
        }
    }

}