Re: [Boost-users] [Thread] barrier destruction after wait() results in assertion

Peter Klotz writes:

Boost 1.37.0, Red Hat Enterprise Linux 5 x86_64, gcc 4.1:

The following simple test establishes a barrier with thread count 2.

One of the threads destroys the barrier after returning from wait(). This results in sporadic assertions from ~mutex().

I assume that this usage of barrier is not supported/allowed. One cannot assume that the barrier can be destroyed just because the corresponding thread returned from wait().

Is this conclusion correct?

You cannot destroy a barrier whilst a thread may be accessing it.

#include #include #include

boost::scoped_ptrboost::barrier barrier;

void f() { barrier->wait(); }

int main(void) { barrier.reset(new boost::barrier(2)); boost::thread thread(boost::bind(&f)); barrier->wait();

At this point, there is no guarantee that f() has started.

barrier.reset();

So this call may have just destroyed the barrier that f is about to wait on.

thread.join(); return 0; }

Anthony -- Anthony Williams Author of C++ Concurrency in Action | http://www.manning.com/williams Custom Software Development | http://www.justsoftwaresolutions.co.uk Just Software Solutions Ltd, Registered in England, Company Number 5478976. Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK