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MADakukanov:
Dear B., thanks for exploring the possibility of MinGW port. I am glad you have made a good progress there. We have identified the problem with MinGW being use of _WIN32 to process compiler-specific portions of code, but have not yet put resources to improve it. If you contribute the patch, we will be glad to merge it back to TBB.
This is something I honestly don't understand. MinGW is GCC for Windows, that is, the most popular open source compiler for the most popular platform. And Intel treats it just as some kind of toy compiler, not worth the time or the work to support it. Intel, the biggest computing company, worth I don't know how many billion dollars, fails to recognize priorities and allocate resources to support what users keep asking. How long is it going to take before you finally decide that maybe MinGW is something Intel needs to support, instead of asking users with no clue of the TBB internals to port it and keep supporting it for you? There are things that users/volunteers can contribute, but major support should come from the main developers.
Look at Trolltech/Qt and their support for compilers and platforms. Smaller company than Intel for sure, with maybe more developers than TBB? OK, but Qt is a much much (much) larger project than TBB, with all the due respect, so things should even out on that, leaving the MinGW support problem on Intel/TBB's shoulders.
Pasquale
How could that __try/__finally block be fixed for MinGW in task.cpp? I'm sure that's the source of some of the crashes.
I discussed it with Arch Robison and we agreed the best thing is to change it over to RAII instead of __try/__finally. I.e. create a local object which destructor does the necessary cleanup.
How is it done on linux? What happens exactly if one of the threads throw an exception (linux/windows)? Does it propagate "out" from the thread?
On Linux (or more correctly, with POSIX threads) you could specify a cleanup handler with pthread_cleanup_{push,pop}.
Exception handling changed a lot in TBB 2.1, while the code in question dates probably back to 1.0. To keep it short, now we try to intercept exceptions in tasks executed by a worker thread, andpropagate those to the master thread that called a TBB algorithm. For safety reasons, however, I would stillkeep that old cleanup code.
As for the exception handling:
The problem is, MinGW doesn't have SEH at all (__try/__finally is noop), and because it's not posix, there are no cleanup handlers either. What could be the solution? What's exactly the RAII solution? Does that mean, that the exception is simply not catched at all?
In simple, RAII is the C++ technique to deal with the kind of problems that __finally is intended to help, i.e. to execute some code independently on whether an exception was caught or not. Read the Wikipedia article for RAIIto get acquainted with it. The idea is simple: put cleanup code into a destructor of an object in the scope of interest, and this destructor will be called. In the particular case, __try/__finally should be removed, a special class (probably local tothe worker_routine function) should be written in a way that its destructors does all required cleanup, and an object of this class should be created in the scope where __try/__finally had resided.
You might as well leave this exercise to us in the TBB team if you do not feel confident about what should be done. If I have little more time to implement it later I can post it here.
