Why doesn't this give a Unhandled Memory Exception
BlitzMax Forums/BlitzMax Programming/Why doesn't this give a Unhandled Memory Exception
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I've allocated 1000000 bytes but Im able to access 3471 bytes more than what I allocated :/Global pMemory:Byte Ptr = MemAlloc(1000000) pMemory[0] = 255 pMemory[1003471] = 255 Print pMemory[1003471] |
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| Haven't you simply put the byte address of the first byte allocated into a byte ptr. The byte ptr can point anywhere you want from there. |
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| You won't se a problem as long as the pointed memory isn't protected. In this case you will run into a segmentation fault or "reasonless" crash. MemAlloc is not controlled by the GC and thus does not raise the normal exceptions, sorry. (there was a MemAlloc version that was GC handled, don't know if it still exists) |
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| (there was a MemAlloc version that was GC handled, don't know if it still exists) Was called GCMalloc, it was removed. Better to just use banks now, since they're practically the same thing only with a public interface. |
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| Why is it still printing the correct value? And if you change the two 1003471's to 1003472's it gives a Unhandled Memory Exception. |
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| Because it's unprotected memory that you're writing to, and unless another process changes it within the incredibly small amount of time between the few instructions for those two lines it will still be the same value when you print it. As for incrementing the pointer, that probably means you're writing to protected memory. |
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| That makes sense, Thanks. |
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