Thread: Compile Public Domain Pocket PC C Program

  1. #1
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    Compile Public Domain Pocket PC C Program

    Hi,

    We are using a product called Superwaba at a Java Virtual Machine on Pocket PC. There is a limitation that we have just found that things (arrays and variables) are only allowed to be 65500 bytes, which isn't big enough for some of the things we need. The program is fully public domain, so there is the source there and I've found what to edit in the C but I just can get it to compile, I've tried VC++ 6, Embedded Visual C++ and something I found called Pelles C for Windows.

    For someone who knows what they are doing, I doubt it is more than an hours work, probably a lot less, so if you'd like a little quick job, post or PM me with a price and if it's fair and you have a good reputation on the board I will send the Paypal immediately.

    Thanks.

    Mike

  2. #2
    Frequently Quite Prolix dwks's Avatar
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    So, you basically want to take the SuperWaba Java virtual machine (which is written in C and interprets Java bytecode), and edit the source to allow objects with sizes larger than 65500 bytes?

    Okay. I'm guessing that the objects are limited to 65500 bytes because internally, something is stored in unsigned 16 bit variables. This means that the variables can hold values from 0 to 65535, inclusive. Perhaps the 35 extras are states of some sort, or perhaps they just wanted a round number for the limit.

    Anyway. If you change those unsigned 16 bit variables to (signed or unsigned) 32 bit variables, it might work. (There might be some other fiddling to do -- there usually is.)

    Why do you need such large variables anyway? You might want to re-think your programming strategy. Or maybe, if you don't need all of that data at once, you could use some sort of paging; write data that's not in use to the disk, and read it again when you need it. You can have extremely large amounts of data in this way. I'm pretty sure that Java even implements this natively. Search for Maps or paging or page files.

    I don't feel like converting it myself at the moment, especially since you've just posted one post and the board hasn't seen you since then. If you post again, explaining why you need variables that size, etc, I'm sure someone might consider it.

    Oh, and BTW, this board doesn't have a reputation system. It got disabled a while ago.
    dwk

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  3. #3
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    dwks,

    Thanks for the reply, it's appreciated.

    You're correct in your assumptions and to hear that the limit is there because of them being 16 bit variables is also good to know as I was hoping just to change the place which caught you trying to assign one which was too big but it sounds a lot worse than that and as such maybe beyond my VERY limted C knowledge.

    The reason for trying to assign such a large variable is that some of the Java is tryng to load a database index into memory (I didn't write this either). The reason why we chose to try to change the superwaba rather than the Java is because we are on a tight deadline and at that point I thought I only had to change one line and recompile, which in theory should have been easy and the way it works now in the Java works and actually isn't that slow. I will definately look into paging in Java that could maybe work for us.

    As for only one post and not back, this is a job for money post, I've also posted on Scriptlance I'm not a C programmer, so have nothing to add to the community or ask of it but I was hoping a very active C forum like this may have someone who would be able to do this job.

    Mike

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