Method LockGuardBase

src/bvar/utils/lock_timer.h:195–198

    DISALLOW_COPY_AND_ASSIGN(LockGuardBase);
public:
    LockGuardBase(Mutex& m)
        : _timer(m), _lock_guard(m.mutex()) {
        _timer.timer.stop();
    }
private:
    // This trick makes the recoding happens after the destructor of _lock_guard
    struct TimerAndMutex {