synchronized boolean drop(Activity a) { boolean ret = activities_.remove(a); pending_.remove(a); tryAdvance_(); return ret;
public boolean drop() { boolean b = drop(aip_.getCurrentActivity()); if (!b) Runtime.getCurrentActivityInformation().getRegisteredClocks().remove(this); return b;
    synchronized boolean drop(Activity a) {        boolean ret = activities_.remove(a);        pending_.remove(a);        tryAdvance_();         return ret;            }