* See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.testing.GcFinalization.awaitClear;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;

import com.google.common.annotations.GwtIncompatible;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.testing.GcFinalization.awaitClear;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;

import com.google.common.annotations.GwtIncompatible;

 *   WeakReference<Foo> weakRef = new WeakReference<>(x);
 *   // ... use x ...
 *   x = null; // Hint to the JIT that x is stack-unreachable
 *   return weakRef;
 * }
 * public void testFooLeak() {
 *   GcFinalization.awaitClear(fooWeakRef());
 * }
 * }
 *
 * <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.
 *

 *   WeakReference<Foo> weakRef = new WeakReference<>(x);
 *   // ... use x ...
 *   x = null; // Hint to the JIT that x is stack-unreachable
 *   return weakRef;
 * }
 * public void testFooLeak() {
 *   GcFinalization.awaitClear(fooWeakRef());
 * }
 * }
 *
 * <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.
 *

    assertTrue(future.isDone());
    assertTrue(future.isCancelled());
  }

  public void testAwaitClear() {
    WeakReference<Object> ref = createWeakReference();
    GcFinalization.awaitClear(ref);
    assertThat(ref.get()).isNull();
  }

  private WeakReference<Object> createWeakReference() {
    return new WeakReference<>(new Object());
  }

    assertTrue(future.isDone());
    assertTrue(future.isCancelled());
  }

  public void testAwaitClear() {
    WeakReference<Object> ref = createWeakReference();
    GcFinalization.awaitClear(ref);
    assertThat(ref.get()).isNull();
  }

  private WeakReference<Object> createWeakReference() {
    return new WeakReference<>(new Object());
  }

    assertThat(sepStopwatchA.get()).isNotNull();
    // Clear all references to the Stopwatch and wait for it to be gc'd.
    sepStopwatchA.set(null);
    GcFinalization.awaitClear(sepStopwatchRef.get());
    // Return a weak reference to the parallel ClassLoader. This is the reference that should
    // eventually become clear if there are no other references to the ClassLoader.

    WeakReference<MyInt> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);
    assertThat(pool.intern(not)).isSameInstanceAs(not);
  }

  private static final class MyInt {
    private final int i;

    MyInt(int i) {
      this.i = i;
    }

    @Override

    WeakReference<MyInt> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);
    assertThat(pool.intern(not)).isSameInstanceAs(not);
  }

  private static final class MyInt {
    private final int i;

    MyInt(int i) {
      this.i = i;
    }

    @Override

          @Override
          public Object computeNext() {
            return new Object();
          }
        };
    WeakReference<Object> ref = doNextAndGetWeakReference(itr);
    GcFinalization.awaitClear(ref);
  }

  @GwtIncompatible // weak references
  private WeakReference<Object> doNextAndGetWeakReference(Iterator<Object> itr) {
    return new WeakReference<>(itr.next());
  }