Re: [Boost-users] Valgrind errors with ASIO

Subject: Re: [Boost-users] Valgrind errors with ASIO
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2013-09-30 02:20:06

On 9/30/2013 5:41 PM, Quoth Bo Jensen:
> I am calling it ala like this :
>
>      /* Create new tasks */
>      basistasks_[workerid] =
> boost::make_shared<boost::packaged_task<BasisSelectRet>
>  >(boost::bind(&CallBasisSelection,&worker,boost::ref(io_error_[workerid])));

What is "worker" here?  Could it become invalid before the join completes?

Also note that when passing it to a different thread it's safer to allow 
the shared_ptr to be copied rather than being passed by reference, 
although this probably isn't related to your current problem.

>    /* Helper function */
>    BasisSelectRet CallBasisSelection(TreeWorker
>    *worker,
>
> boost::shared_ptr<ExceptionTransfer> &error)
>    {
>      BasisSelectRet ret = BasisSelectRetOk;
>
>      try
>      {
>        worker->BasisSelection();
>      }
>      catch( ... )
>      {
>        error->SetException(boost::current_exception());
>      }
>
>      return ret;
>    }

You probably shouldn't be catching exceptions here.  packaged_task will 
do that for you anyway, and as it stands I think there's a slim chance 
of a broken_promise exception that will bypass this code, so you'd need 
to catch where you're accessing the futures anyway.  (If your number of 
jobs is larger than your number of threads.)