* only meant as a utility for developers that want to employ the model builder outside of the Maven build system, Maven
 * plugins should always acquire model builder instances via dependency injection. Developers might want to subclass
 * this factory to provide custom implementations for some of the components used by the model builder.
 *

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

This lock guards internal state of each connection. This lock is never held for blocking operations. That means that we acquire the lock, read or write a few fields and release the lock. No I/O and no application-layer callbacks.

#### Http2Stream

    void contextAccessor() {
        assertSame(ctx, transport.getContext());
    }

    @Test
    @DisplayName("acquire returns same instance")
    void acquireReturnsSameInstance() {
        SmbTransportImpl acquired = transport.acquire();
        assertSame(transport, acquired);
        transport.close(); // release once
    }

    @Test

///

### `startup` and `shutdown` together { #startup-and-shutdown-together }

There's a high chance that the logic for your *startup* and *shutdown* is connected, you might want to start something and then finish it, acquire a resource and then release it, etc.

Doing that in separated functions that don't share logic or variables together is more difficult as you would need to store values in global variables or similar tricks.

   * cancelled without a call to {@code cancel}, such as by calling {@code
   * setFuture(cancelledFuture)}.
   *
   * <p>Beware of completing a future while holding a lock. Its listeners may do slow work or
   * acquire other locks, risking deadlocks.
   */
  @CanIgnoreReturnValue
  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    @RetainedLocalRef Object localValue = value();
    boolean rValue = false;

// it is similar to LockedOpenFile with with syscall.LOCK_EX
// mode but along with syscall.LOCK_NB such that the function
// doesn't wait forever but instead returns if it cannot
// acquire a write lock.
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	var lockType uint32 = lockFileFailImmediately | lockFileExclusiveLock
	if flag == syscall.O_RDONLY {

    } finally {
      if (!satisfied) {
        leave();
      }
    }
  }

  /**
   * Enters this monitor when the guard is satisfied. Blocks at most the given time, including both
   * the time to acquire the lock and the time to wait for the guard to be satisfied, and may be
   * interrupted.
   *
   * @return whether the monitor was entered, which guarantees that the guard is now satisfied

	for i := range nodes {
		clnts = append(clnts, newClient(nodes[i].URL))
	}

	ds = &Dsync{
		GetLockers: func() ([]NetLocker, string) { return clnts, uuid.New().String() },
		Timeouts: Timeouts{
			Acquire:         testDrwMutexAcquireTimeout,
			RefreshCall:     testDrwMutexRefreshCallTimeout,
			UnlockCall:      testDrwMutexUnlockCallTimeout,
			ForceUnlockCall: testDrwMutexForceUnlockCallTimeout,
		},
	}

    /**
     * Acquires a reference to this transport, incrementing the usage count.
     *
     * @return session increased usage count
     */
    public Transport acquire() {
        final long usage = this.usageCount.incrementAndGet();
        if (log.isTraceEnabled()) {
            log.trace("Acquire transport " + usage + " " + this);
        }
        return this;

  Striped64() {}

  /** CASes the base field. */
  final boolean casBase(long cmp, long val) {
    return UNSAFE.compareAndSwapLong(this, BASE_OFFSET, cmp, val);
  }

  /** CASes the busy field from 0 to 1 to acquire lock. */
  final boolean casBusy() {
    return UNSAFE.compareAndSwapInt(this, BUSY_OFFSET, 0, 1);
  }

  /**
   * Computes the function of current and new value. Subclasses should open-code this update