Method ScopedLockHead

thread/thread.cpp:1676–1677

    {
        thread* _th;
        ScopedLockHead(waitq* waitq) :
            _th(indirect_lock(&waitq->q.th)) { }
        operator thread*()   { return _th; }
        thread* operator->() { return _th; }
        ~ScopedLockHead()    { if (_th) _th->lock.unlock(); }