 | | Re: threads - bug in the firmware? —Mike McFarlane
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| | | Hi again I have now totally stripped down my code to a minimum and I am still having problems with the code hanging up. I can see nowhere where there can be a fault. I am a long way from being an expert, but is it possible there is a bug in the (...) (23 years ago, 16-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | Re: threads - bug in the firmware? —Eric Swalens
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| | | | | (...) As pointed by Albert Huang, you cannot call kill() with an "invalid" pid. Actually, the comment above kill() in tm.c says: //! kill a process /*! \param pid must be valid process ID, or undefined behaviour will result! The function updates (...) (23 years ago, 16-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | Re: threads - bug in the firmware? —Michael Obenland
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| | | | Hi Mike, your problem is not because of an error in legOS. But what you do is that you start your subroutines and then you leave main()! Leaving main means that all your allocated memory is freed. The following will do the job: ---...--- cut here (...) (23 years ago, 17-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: threads - bug in the firmware? —Mike McFarlane
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| | | | | ;-) That worked a treat, thanks Michael. (thanks for the other little corrections in the code too). mike (...) Mike, (...) your subroutines and then you leave main()! Leaving main means (...) memory is freed. The following will do the job: (...) (...) (23 years ago, 17-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: threads - bug in the firmware? —Ross Crawford
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| | | | | (...) Note also since bumper_task() is an infinite loop, and you never use pid1, you could save one thread by doing this: int main(int argc, char *argv[]) { pid2 = execi (&left_task, 0, NULL, PRIO_NORMAL+2, DEFAULT_STACK_SIZE); pid3 = execi (...) (23 years ago, 17-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | | Re: threads - bug in the firmware? —Mike McFarlane
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| | | | | | Hi Ross (...) you (...) What are the advantages and disadvantages of this method as opposed to the one I used? mike (23 years ago, 18-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | | | Re: threads - bug in the firmware? —Ross Crawford
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| | | | | | (...) Advantage: Less memory used (each thread needs a block of memory in the kernel, I'm at work & can't remember the struct name off hand). In the case under discussion, this doesn't make much difference, but in a large project, memory use can (...) (23 years ago, 21-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: threads - bug in the firmware? —Michael Ash
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| | | | (...) I would strongly suggest changing this to while(1) msleep(bignumber);. Otherwise you're hogging the processor doing nothing important, which could do bad things to any compute-intensive tasks you may have going. It'll also use slightly less (...) (23 years ago, 18-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | More on threads —Michael Obenland
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| | | | (...) Of course you are right. I think it is a bad programming style not to give your program the ability to terminate but to run in an endless loop. But what is the penalty for this bad style? I've done some investigations and here are the results: (...) (23 years ago, 18-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: More on threads —Mike McFarlane
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| | | | (...) ability to terminate but to run in an endless loop. But This is not true of an embedded system though which will have to run 'forever'. (...) priority of NORMAL+4. So, the (...) any time slice at all. NO time slice or just a very small chunk (...) (23 years ago, 19-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: More on threads —Michael Obenland
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| | | | (...) Digging through tm.c gave me the impression, that main will indeed get no time slice. So I wrote another test program: ---...--- #include <conio.h> #include <unistd.h> pid_t worker; int work_task(int argc, char *argv[]); int main() { int i; i (...) (23 years ago, 19-Jan-02, to lugnet.robotics.rcx.legos)
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| | | | | | Re: More on threads —Michael Ash
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| | | | (...) I recall that legOS's priority model is pretty rigid. If a thread with a higher priority never yields, threads with lower priority will never get any time. When I write legOS programs, I generally just have everything run at PRIO_NORMAL. That (...) (23 years ago, 19-Jan-02, to lugnet.robotics.rcx.legos)
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