ready, err := p.blockUntilWaitable()
	if err != nil {
		return nil, err
	}
	if ready {
		// Mark the process done now, before the call to Wait4,
		// so that Process.pidSignal will not send a signal.
		p.pidDeactivate(statusDone)
		// Acquire a write lock on sigMu to wait for any
		// active call to the signal method to complete.
		p.sigMu.Lock()
		p.sigMu.Unlock()
	}

	var (
		status syscall.WaitStatus

	if err != nil {
		return nil, NewSyscallError("wait", err)
	}

	p.pidDeactivate(statusDone)
	ps = &ProcessState{
		pid:    waitmsg.Pid,
		status: &waitmsg,
	}
	return ps, nil
}

func (p *Process) release() error {
	p.Pid = -1

	// Just mark the PID unusable.
	p.pidDeactivate(statusReleased)

	// no need for a finalizer anymore
	runtime.SetFinalizer(p, nil)
	return nil
}