Apologies for the issue, I was getting output from the 2 processes, and their threads, and I was focused on only 1 process.
Please ignore, On 13 February 2014 14:33, MM <finjulh...@gmail.com> wrote: > Hello, > > I am running a MPI application on a single host, with a dual quadcore with > hyperthreading on. (16 OS-visible processors), but just in debug mode > (msvc2010) 32bit, with 2 mpi processes only. > > mpirun -mca btl_tcp_if_exclude lo -np 1 prog1.exe : -np 1 prog2.exe > > . when progr1.exe has 1 thread (mpi never initialized), everything works > fine. > . when progr2.exe has 2 threads (1 thread with no call to mpi functions, > and a second thread where mpi is initialized, through a default ctor of > boost::mpi::environment, I think thos means just a call to MPI_Initialize() > ), ompi_info gives "Threading support: No" > > 1. I start prog1, create addition thread boost::thread that handles MPI > calls. > 2. proceed to a point where both thread1 and threadMPI, not concurrently, > call a function f(). > f() initializes a global const std::string* X=null, to a static, this X is > visible from both threads. > > In fact, it appears at a certain point during a boost::mpi::broadcast, > within threadMPI, boost::mpi calls MPI_Isend (point_to_point.cpp: 53), > during this Isend, a 3rd thread (not threadMPI) is created and causes a > call to f() which doesn't see X as !=nullptr. > > I can see this while debugging with msvc, and stepping into MPI_Isend (i > don't have the sources for it). At that moment, suddenly a new thread is > created, and a call to f() is made. > > This all sounds quite nightmarish. > > I understand I haven't presented any specific code to receive an accurate > answer, but any help is appreciated. > > Regards, > > MM >
