In earlier posts I reviewed three of the four winning submissions to the "Coding with TBB" contest that was launched at OSCON and which completed on August 31. In this post I look at the fourth winning entry, AJ Guillon's YetiSim.

YetiSim is:

Exception handling is one of the big improvements of C++ over C. C code that checks for erroneous or unusual conditions is littered with tests for those conditions, making programs harder to read. Worse yet, the programmer might forget to check one of those conditions. Exceptions eliminated most of those problems, albeit opened up the new issue of exception safety.

Unfortunately, exceptions as practiced in C++ tend to force sequential execution of code. Consider:

    float a[N];

    float b[N];

    ...

    for( int i=0; i<N; ++i )

Last week I showed how cache affinity support might be supported by the high-level algorithm templates. Here's what the low-level task interface might look like. There would be a new subclass of class task for tasks with affinity, called task_with_affinity.  As much as I would prefer to avoid subclassing here, we have to because introducing new virtual methods into class task would break binary compatibility of task's vtable.  Such is the price of graceful evolution.

The subclass adds a simple interface:

As promised in my last post, I took a closer look at the code changes and additions Vincent Tan made to multithread the par2cmdline utility using Threading Building Blocks.

TBB-threaded par2cmdline implementation notes