2016/01/08

DISCLAIMER: These notes are from the defunct k8 project which precedes SquirrelJME. The notes for SquirrelJME start on 2016/02/26! The k8 project was effectively a Java SE 8 operating system and as such all of the notes are in the context of that scope. That project is no longer my goal as SquirrelJME is the spiritual successor to it.

07:26

Today I woke up early before the sun rise, which has yet to appear above the mountains and leafless trees for me. The clouds reflecting off the top are an interesting red. But a bright beam will be very noticable when it starts moving down on my walls.

07:41

Thinking about this, I currently operate with a patch. I believe what I should do instead is have a from which is any binary type and then a to which is a patch type.

07:55

That may result in faster getting a kernel compiled because I may not have to implment all of the patch stuff yet. Although on writing I will have to implement it all, so this is just a defer. However by not using a patch as a basis and having a target I can instead make processing a bit faster because then the constant pool and reference table will not require copying and such.

08:28

I can also have a single class which contains input and output along with the configuration used for dynamic recompilation.

08:30

The thing however, is what to call this new class.

08:33

It is not a configuration, but it stores one and has input and output. It is a result but it is also input. Perhaps a State could work, then I could also have a kind of flag indicating what the recompiler is doing if possible, or a progress meter (if supported). Then classes which call the dynamic recompiler code can be told how far along recompilation is.

08:50

Primaries might be a bad choice, but individual classes would be best.

15:53

Forgot about equals and hash code for all the references.

16:12

And for the constant pool entries also. Also realized that using a special tag type for null references I can now have references to null entries despite that probably not being very useful.

16:24

Also in the constant stuff, not using DescriptorClassName and instead using the derived DescriptorField will result in potentially less bugs because DescriptorBinaryName and DescriptorField do not compare.

17:20

This will be a problem with the way my patch stuff is setup:

net.multiphasicapps.k8.bin.patch.PatchCodeRef.getSlot
net.multiphasicapps.poit.std.StandardRISCTranslator.loadCodeRefPointer

I should probably just remove the getSlot because that can be tricky to implement.

17:27

I can use a cache of code references, assuming one does not modify a class while it is being recompiled, but that is undefined anyway.

17:32

I wonder if I should make a distinction with the native CPU size and the size of a pointer. That could complicate memory models and such however it would mean that for 64-bit systems I can use less memory because pointers would be 32-bit. 64-bit arithmetic would see a boost, however it would affect all software because it uses the same dynamic recompiler. For system calls however I would have to be able to handle that although there is a bunch of base stuff in Object's code that uses long regardless.

17:51

So right now I have two choices, I can keep all the compiled classes in memory or I can just store them to the disk and never reference them (so they eventually get garbage collected).

22:16

The KBF handling is going to have to be refactored because right now the code is really ugly. It may be possible for the data to be shared between the reader and the writer.