Проясните, пожалуйста. "Жарим" процессор или я чего-то не понял?

...\Microsoft Visual Studio 14.0\VC\crt\src\stl\primitives.h

    class stl_critical_section_vista final : public stl_critical_section_interface
    {
    public:
        stl_critical_section_vista()
        {
            __crtInitializeCriticalSectionEx(&_M_critical_section, 4000, 0);
        }
        ...
        virtual bool try_lock() override
        {
            return TryEnterCriticalSection(&_M_critical_section) != 0;
        }
        virtual bool try_lock_for(unsigned int) override
        {
            // STL will call try_lock_for once again if this call will not succeed
            return stl_critical_section_vista::try_lock();
        }
        ...
    private:
        CRITICAL_SECTION _M_critical_section;
    };

    class stl_critical_section_win7 final : public stl_critical_section_interface
    {
    public:
        ...
        virtual bool try_lock() override
        {
            return __crtTryAcquireSRWLockExclusive(&m_srw_lock) != 0;
        }
        virtual bool try_lock_for(unsigned int) override
        {
            // STL will call try_lock_for once again if this call will not succeed
            return stl_critical_section_win7::try_lock();
        }
        ...
    private:
        SRWLOCK m_srw_lock;
    };

...\Microsoft Visual Studio 14.0\VC\crt\src\stl\mutex.c

static int mtx_do_lock(_Mtx_t mtx, const xtime *target)
{
    ...
    /* check timeout */
    xtime now;
    xtime_get(&now, TIME_UTC);
    while (now.sec < target->sec
        || now.sec == target->sec && now.nsec < target->nsec)
    {    /* time has not expired */
        if (mtx->thread_id == static_cast<long>(GetCurrentThreadId())
            || mtx->_get_cs()->try_lock_for(_Xtime_diff_to_millis2(target, &now)))
        {    /* stop waiting */
            res = WAIT_OBJECT_0;
            break;
        }
        else
            res = WAIT_TIMEOUT;

        xtime_get(&now, TIME_UTC);
    }
    ...
}

Всё. Сам понял. Вопрос снимается.