[Boost-users] boost::thread waiting problem

From: Ovanes Markarian (om_boost_at_[hidden])
Date: 2005-08-29 19:42:12

Hello,

I have the following scenario:
Evaluate String Stream until a certain string is found or a time has occured. The string
evaluation is made not in a single function, but using a stream iterator and later an evaluator of
the retrieved data.

I have an iterator class as function object where a
boost::shared_ptr<boost::timed_mutex> mutex;
member is defined. It has 2 functions:
operator()() which is a worker function of the time_out thread and an iteratorion function.

Now I start when entered for the first time the iteration function the time_out thread. The
time_out thread should block until the time_out elapses or the another function has found the
desired string from the stream.

my code looks like:

operator()()
{
        boost::timed_mutex::scoped_timed_lock lock(*mutex, true);

        boost::condition c;

        boost::xtime	xt;
        boost::xtime_get(&xt, boost::TIME_UTC);

        xt.sec +=20;

        c.timed_wait(lock, xt);
}

My approach was to use the mutex object for syncronization. I assumed that it is locked as long as
c.timed_wait(...) is waiting.

So I try to lock this object in the other thread. If the mutex object can not be locked the worker
thread is still waiting, otherwise time_out elapsed.

>From the Rationale section of the thread docs I heavily understand which locking strategy is used
for timed_mutex. Can someone point me to a the correct place with documentation and say if this
approach will work or I should consider a redesign?

With Kind Regards,

Ovanes Markarian