Question

I added openMp code to some serial code in a simulator applicaton, when I run a program that uses this application the program exits unexpectedly with the output "The thread Win32 Thread (0x1828) has exited with code 1 (0x1)", this happens in the parallel region where I added the OpenMp code, here s a code sample:

#pragma omp parallel for private (curr_proc_info, current_writer, method_h) shared (exceptionOccured) schedule(dynamic, 1) 
    for (i = 0 ; i < method_process_num ; i++)
    {
         current_writer = 0;
        // we need to add protection before we can dequeue a method from the methods queue,

        #pragma omp critical(dequeueMethod)  
        method_h = pop_runnable_method(curr_proc_info, current_writer);

        if(method_h !=0 && exceptionOccured == false){
            try {
            method_h->semantics();
            }
            catch( const sc_report& ex ) {
                ::std::cout << "
" << ex.what() << ::std::endl;
                m_error = true;
                exceptionOccured = true;  // we cannot jump outside the loop, so instead of return we use a flag and return somewhere else
            }

        }
    }

The scheduling was static before I made it dynamic, after I added dynamic with a chunk size of 1 the application proceeded a little further before it exited, can this be an indication of what is happening inside the parallel region? thanks

Answer 1

As I read it, and I m more of a Fortran programmer than C/C++, your private variable curr_proc_info is not declared (or defined ?) before it first appears in the call to pop_runnable_method. But private variables are undefined on entry to the parallel region.

I also think your sharing of exception_occurred is a little fishy since it suggests that an exception on any thread should be noticed by any thread, not just the thread in which it is noticed. Of course, that may be your intent.

Cheers

Mark

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