[boost] [thread] Exception based timed locks

Subject: [boost] [thread] Exception based timed locks
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2009-01-19 19:03:28

Hi,

I've read recently about timed locks throwing an exception when there is a timeout.
What do you think about this behaviour?
Could the thread library provide both?

Next follows a piece of code without exceptions

    while (polling) {
        t=now()+100;
        boost::unique_lock<boost::mutex> l1(m1, t);
        if (l1.has_lock() {
            boost::unique_lock<boost::mutex> l2(m2, t);
            if (l2.has_lock() {
                boost::unique_lock<boost::mutex> l3(m3, t);
                if (l2.has_lock() {
                    foo();
                    polling = false;
                } else execute_on_failed(); 
            } else execute_on_failed(); 
        } else execute_on_failed(); 
    }

and now with exceptions

    while (polling)
        try {
            t=now()+100;
            boost::exception_unique_lock<boost::mutex> l1(m1, t);
            boost::exception_unique_lock<boost::mutex> l2(m2, t);
            boost::exception_unique_lock<boost::mutex> l3(m3, t);
            foo();
            polling = false;
        } catch (timeout_exception& ex) {execute_on_failed(); }

What do you think about a try_lock_until, try_lock_for functions

    while (polling)
        try {
            boost::try_lock_for(100, m1, m2, m3);
            foo();
            polling = false;
        } catch (timeout_exception& ex) {execute_on_failed(); }

Best,
Vicente