import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import javax.annotation.CheckForNull;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee

    assertNull(spec.initialCapacity);
    assertNull(spec.maximumSize);
    assertNull(spec.maximumWeight);
    assertNull(spec.concurrencyLevel);
    assertNull(spec.keyStrength);
    assertEquals(Strength.SOFT, spec.valueStrength);
    assertNull(spec.writeExpirationTimeUnit);
    assertNull(spec.accessExpirationTimeUnit);
    assertCacheBuilderEquivalence(CacheBuilder.newBuilder().softValues(), CacheBuilder.from(spec));
  }

    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.of(STRONG, Strength.WEAK, Strength.SOFT));
  }

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();
    return Iterables.transform(
        factory.buildAllPermutations(),

import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import javax.annotation.CheckForNull;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee

        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {
          Object canonical = entry.getKey();
          if (canonical != null) { // only matters if weak/soft keys are used
            // The compiler would know this is safe if not for our use of raw types (see above).
            @SuppressWarnings("unchecked")
            E result = (E) canonical;
            return result;

    return this;
  }

  CacheBuilderFactory withKeyStrengths(Set<Strength> keyStrengths) {
    this.keyStrengths = Sets.newLinkedHashSet(keyStrengths);
    Preconditions.checkArgument(!this.keyStrengths.contains(Strength.SOFT));
    return this;
  }

  CacheBuilderFactory withValueStrengths(Set<Strength> valueStrengths) {
    this.valueStrengths = Sets.newLinkedHashSet(valueStrengths);
    return this;
  }

        buildContext.getResult().addException(t);
        buildContext.getResult().addBuildSummary(new BuildFailure(mavenProject, buildEndTime - buildStartTime, t));

        // notify listeners about "soft" project build failures only
        if (t instanceof Exception && !(t instanceof RuntimeException)) {
            eventCatapult.fire(ExecutionEvent.Type.ProjectFailed, currentSession, null, (Exception) t);
        }

          .put("concurrencyLevel", new ConcurrencyLevelParser())
          .put("weakKeys", new KeyStrengthParser(Strength.WEAK))
          .put("softValues", new ValueStrengthParser(Strength.SOFT))
          .put("weakValues", new ValueStrengthParser(Strength.WEAK))
          .put("recordStats", new RecordStatsParser())
          .put("expireAfterAccess", new AccessDurationParser())

 * }
 * public void testFooLeak() {
 *   GcFinalization.awaitClear(fooWeakRef());
 * }
 * }</pre>
 *
 * <p>This class cannot currently be used to test soft references, since this class does not try to
 * create the memory pressure required to cause soft references to be cleared.
 *
 * <p>This class only provides testing utilities. It is not designed for direct use in production or
 * for benchmarking.
 *

    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.of(STRONG, Strength.WEAK, Strength.SOFT));
  }

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();
    return Iterables.transform(
        factory.buildAllPermutations(),