Now I understand! Thank you both! Regards, -- Ricardo
On Mon, Dec 21, 2009 at 11:59 AM, Guillermo De Cesco <[email protected]>wrote: > Hi, > > That means that you have to implement your own memory management component > and define a parameterized interface that allows you to manage clients, so > in your application if a module needs dynamic memory its just connect to > this interface.Note that you will be allocating memory with your > implementation not malloc. > > -Bill > > > On Mon, Dec 21, 2009 at 7:15 AM, Ricardo . <[email protected]>wrote: > >> These give me a great help to understand these issues of dynamic memory, >> and for that thank you! I have just one more question: >> >> In "tinyos-programming.pdf" is said: "If your application requirements >> necessitate a >> dynamic memory pool, encapsulate it in a component and try to limit the >> set of users." -- This means that any code that uses dynamic memory should >> be done in a separate component? I see no relevance in this ... : S >> >> On Sun, Dec 20, 2009 at 9:37 PM, Faisal Aslam < >> [email protected]> wrote: >> >>> Dear Ricardo, >>> >>> > First of all thank you for your answer. >>> > >>> > Is slower because it has to find a contiguous space of memory large >>> enough >>> > to reserve, or is there another reason(s)? >>> >>> May be someone with more experience in C can give better reply on this. >>> However, it is slower for sure. It takes CPU cycle to manage memory, i.e. >>> to allocate and deallocate space. >>> >>> > If it is possible in all versions of TinyOS, why in some of the >>> literature >>> > says it is not possible? : S >>> >>> I do not know any literature that says it is not allowed to use dynamic >>> memory in TinyOS. One can write plan C code in TinyOS and C allows >>> dynamic >>> memory allocation in MSP430 and AVR microcontroller. I know it because we >>> have done that. >>> >>> best regards, >>> >>> -- >>> Faisal Aslam >>> >>> PhD Student >>> University of Freiburg >>> http://cone.informatik.uni-freiburg.de/people/aslam/ >>> > On Fri, Dec 18, 2009 at 5:38 PM, Faisal Aslam < >>> > [email protected]> wrote: >>> > >>> >> Dear Ricardo, >>> >> Here is my take on your questions. See inline. >>> >> >>> >> >>> >> Ricardo . wrote: >>> >> >>> >>> >>> >>> Dear all, >>> >>> >>> >>> I need your help to clear up a question: my application needs dynamic >>> >>> memory, and literature that I've found some say it is not possible, >>> >>> other >>> >>> say it's possible but it is not efficient. >>> >>> >>> >>> My questions are: >>> >>> >>> >>> 1 - Which version of TinyOS is possible to use dynamic memory? >>> >>> >>> >> In all the versions. You can write pure C code in TinyOS and all >>> >> compilers >>> >> I know support dynamic memory. >>> >> >>> >> 2 - Any mote supports dynamic memory? >>> >>> >>> >> All motes. >>> >> >>> >> 3 - What is the reason for dynamic memory is not efficient? >>> >>> 4 - Using dynamic memory greatly affects the efficiency, or is almost >>> >>> imperceptible? >>> >>> >>> >> The answer of both question 3 and 4 is as follows. Dynamic memory >>> means >>> >> that you cannot predict memory usage at compile time and could go out >>> of >>> >> memory easily. You have to deallocate memory yoursef carefully. There >>> >> are >>> >> more chances of complicated errors. The allocating and deallocating >>> >> memory >>> >> is slow process and your code will execute slower. The static memory >>> >> allocation is much more safer and faster. >>> >> You can also program your motes using Java. It has automatic garbage >>> >> collection and will give you "out of memory" error. It is usually >>> safer >>> >> to >>> >> use Java then C. Unlike C in Java you cannot have segmentation fault. >>> >> You >>> >> can use data structure like Vector that will grow dynamically etc. >>> >> >>> >> >>> >>> >>> >>> I wonder if anyone knows explain some of these issues (preferably all >>> >>> =)), >>> >>> or if anyone know of any literature where I can get answers. >>> >>> >>> >>> Thankyou very much, >>> >>> -- >>> >>> Ricardo >>> >>> >>> >> >>> >> -- >>> >> Faisal Aslam >>> >> >>> >> University of Freiburg >>> >> http://cone.informatik.uni-freiburg.de/people/aslam/ >>> >> >>> >> >>> > _______________________________________________ >>> > Tinyos-help mailing list >>> > [email protected] >>> > >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >>> >>> >>> >>> >> >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> > > > > -- > Ing. Guillermo De Cesco > Invenio Ingenieria srl. > tel: (54)2944 442119 > cel:(54)2944 15534750 > web: www.invenioing.com > Av. Pioneros 4163 Dpto 6. CP(R8402AMH) > San Carlos de Bariloche. > Rio Negro, Argentina. >
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