mu2 := lockedfile.MutexAt(mu.Path)
	t.Logf("mu2 := MutexAt(mu.Path)")

	wait := mustBlock(t, "mu2.Lock()", func() {
		unlock2, err := mu2.Lock()
		if err != nil {
			t.Errorf("mu2.Lock: %v", err)
			return
		}
		t.Logf("unlock2, _ := mu2.Lock()")
		t.Logf("unlock2()")
		unlock2()
	})

	t.Logf("unlock()")
	unlock()
	wait(t)
}

func TestReadWaitsForLock(t *testing.T) {
	t.Parallel()

			if w.waiting == w.running {
				// All done.
				w.wait.Broadcast()
				w.mu.Unlock()
				return
			}
			w.wait.Wait()
			w.waiting--
		}

		// Pick something to do at random,
		// to eliminate pathological contention
		// in case items added at about the same time
		// are most likely to contend.
		i := rand.Intn(len(w.todo))
		item := w.todo[i]
		w.todo[i] = w.todo[len(w.todo)-1]
		w.todo = w.todo[:len(w.todo)-1]

      }
      barrier.await(); // release the threads!
      barrier.await(); // wait for them all to complete
      assertEquals(1, task.get().intValue());
      assertEquals(1, counter.get());
    }
    executor.shutdown();
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait
  public void testToString() throws Exception {
    final CountDownLatch enterLatch = new CountDownLatch(1);

        } catch (final ExecutionException e) {
            // no thing to do
        }

        long elapsed = (System.nanoTime() - time) / 1000000;
        long wait = waittime * (numTasks - 1);
        assertTrue(elapsed + " >= " + wait, elapsed + 1L >= wait);
    }

    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, TimeUnit.SECONDS));

		},
		func(s *script.State, args ...string) (script.WaitFunc, error) {
			b := work.NewBuilder(s.Getwd())
			wait, err := cmdExec.Run(s, append(b.GccCmd(".", ""), args...)...)
			if err != nil {
				return wait, err
			}
			waitAndClean := func(s *script.State) (stdout, stderr string, err error) {
				stdout, stderr, err = wait(s)
				if closeErr := b.Close(); err == nil {
					err = closeErr
				}
				return stdout, stderr, err
			}

      }
      barrier.await(); // release the threads!
      barrier.await(); // wait for them all to complete
      assertEquals(1, task.get().intValue());
      assertEquals(1, counter.get());
    }
    executor.shutdown();
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait
  public void testToString() throws Exception {
    final CountDownLatch enterLatch = new CountDownLatch(1);

    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, TimeUnit.SECONDS));

    }
    return new ListenableFutureAdapter<>(future, executor);
  }

  /**
   * An adapter to turn a {@link Future} into a {@link ListenableFuture}. This will wait on the
   * future to finish, and when it completes, run the listeners. This implementation will wait on
   * the source future indefinitely, so if the source future never completes, the adapter will never
   * complete either.
   *

				t.Log(strings.TrimSuffix(log.String(), "\n"))
			}
		}()

		if testing.Verbose() {
			// Add the environment to the start of the script log.
			wait, err := script.Env().Run(s)
			if err != nil {
				t.Fatal(err)
			}
			if wait != nil {
				stdout, stderr, err := wait(s)
				if err != nil {
					t.Fatalf("env: %v\n%s", err, stderr)
				}
				if len(stdout) > 0 {
					s.Logf("%s\n", stdout)
				}
			}
		}