handle.set_device(device_->name());
    handle.set_container(rm->default_container());
    handle.set_name(name);
    TypeIndex type_index = TypeIndex::Make<Var>();
    handle.set_hash_code(type_index.hash_code());
    handle.set_maybe_type_name(type_index.name());

    Tensor* input = new Tensor(host_allocator_, DT_RESOURCE, TensorShape({}));
    input->scalar<ResourceHandle>()() = handle;
    tensors_.push_back(input);

    handle.set_device(device_->name());
    handle.set_container(rm->default_container());
    handle.set_name(name);
    TypeIndex type_index = TypeIndex::Make<Var>();
    handle.set_hash_code(type_index.hash_code());
    handle.set_maybe_type_name(type_index.name());

    Tensor* input = new Tensor(host_allocator_, DT_RESOURCE, TensorShape({}));
    input->scalar<ResourceHandle>()() = handle;
    tensors_.push_back(input);

 * This implementation also requires GC to track two separate objects (the {@code HashCode} object and its {@code byte[]}).
 * <p>
 * Because Gradle uses a lot of MD5 hashes, for 128-bit hashes we have a more efficient implementation.
 * {@link HashCode128} uses two longs to store the bits of the hash, and does not need to cache the {@link #hashCode()} either.

    bytesB[4] = (byte) 0xef;

    HashCode hashCodeA = HashCode.fromBytes(bytesA);
    HashCode hashCodeB = HashCode.fromBytes(bytesB);

    // They aren't equal...
    assertFalse(hashCodeA.equals(hashCodeB));

    // But they still have the same Object#hashCode() value.
    // Technically not a violation of the equals/hashCode contract, but...?
    assertEquals(hashCodeA.hashCode(), hashCodeB.hashCode());
  }

        HashCode hashCode = implementationHash != null
            ? implementationHash
            : calculateClassLoaderHash(classPath);
        ClassLoader classLoader = super.doCreateClassLoader(name, parent, classPath);
        hashCodes.put(classLoader, hashCode);
        return classLoader;
    }

    @Override

    for (HashCode hashCode : hashCodes) {
      byte[] nextBytes = hashCode.asBytes();
      checkArgument(
          nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
      for (int i = 0; i < nextBytes.length; i++) {
        resultBytes[i] = (byte) (resultBytes[i] * 37 ^ nextBytes[i]);
      }
    }
    return HashCode.fromBytesNoCopy(resultBytes);
  }

    for (HashCode hashCode : hashCodes) {
      byte[] nextBytes = hashCode.asBytes();
      checkArgument(
          nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
      for (int i = 0; i < nextBytes.length; i++) {
        resultBytes[i] = (byte) (resultBytes[i] * 37 ^ nextBytes[i]);
      }
    }
    return HashCode.fromBytesNoCopy(resultBytes);
  }

        expect:
        weakKey1 == weakKey2
    }

    def "hashCode of weakKey is system identity hashCode"() {
        Thing thing = new Thing("thing")
        WeakIdentityHashMap.WeakKey<Thing> weakKey = new WeakIdentityHashMap.WeakKey<>(thing)

        expect:
        weakKey.hashCode() == System.identityHashCode(thing)
    }

    class Thing {
        String name

import org.gradle.internal.hash.HashCode;

public class DefaultBuildCacheKey implements BuildCacheKeyInternal {
    private final HashCode hashCode;

    public DefaultBuildCacheKey(HashCode hashCode) {
        this.hashCode = hashCode;
    }

    @Override
    public String getHashCode() {
        return hashCode.toString();
    }

    @Override
    public HashCode getHashCodeInternal() {

package org.gradle.caching.internal;

import org.gradle.internal.hash.HashCode;

public class SimpleBuildCacheKey implements BuildCacheKeyInternal {
    private final HashCode hashCode;

    public SimpleBuildCacheKey(HashCode hashCode) {
        this.hashCode = hashCode;
    }

    @Override
    public HashCode getHashCodeInternal() {
        return hashCode;
    }

    @Override
    public String getHashCode() {