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.
00:07
I am going to require some kind of relative system for class files in their native KBF form. One main thing is I will need to have a relative addressed based on an absolute location. This way it is easier to share loaded KBFs and classes among multiple processes in the system. So rather than requiring multiple base class initialized forms, it can just use solely just the one instance which is mapped somewhere. This is so memory usage is reduced as much as possible and so unused classes may be removed from memory or from a process. If addressable and executable ROM space exists then there will never be a need to swap out since it would be rather pointless to begin with. Although the more classes in active memory, the less heap space is available for programs to use. So a major thing to think on is the object format in memory and in KBF. I will want them to be both the same so they can be directly mapped as needed, provided the architecture it targets is the same. So the main KBF will include a binary serialization of the FormClass type which exactly matches that of the running system. Then all objects are just mappings of that. This however would mean that the cache must be wiped when a new FormClass is used or if there are any architectural changes. However, such classes are compiled ahead of time cached results. Users should not be running around with KBF distribution as it is a volatile format that changes to suit the architecture it runs on. So the main importance of the KBF format will be directly accessible as an object class types and such. One main difficulty of this is how the class types and such will map in their BinaryName forms when they refer to types. I could use a String based hashmap but that would be very collidy depending on the classes used. Since KBFs are raw binaries which might be executed directly in ROM, the format and run-time in memory format of objects will need to handle such things. So perhaps the KBFs will instead contain a hopefully unique identifier of sort (hash) which maps to a table of information. There is another alternative. The FormClass information is a built raw set of information which points to other things. I can have a primitive set of objects used to refer to things. I must figure out a good system that is fast enough and is simple to use by the recompilation system. So I should write a utility which goes through a class file and determines the Java hash sums to see how viable things are collision wise with many many classes.
00:28
I wonder if direct buffers would apply to me since everything is in Java. I am thinking of arrays just being a size point, component type, and a pointer to the data of the array (which may be anywhere). The code I write could just treat direct and indirect buffers the same way, and they both can use a backing array since internally they look the same. The one main thing in my code however is detection for stuff such as loops which copy everything. That will need to be folded into a single instruction when it is found and generated with the correct bounds checking for the range. That it, if it is a simplistic copy operation. However, I can just skip detecting optimizations like that in the early stage. Why? Because it would be premature optimization. I have no idea how the dynarec will work since it is only partially complete in a way. So the first generation of native code generators will be a bit slow. Then in the future, me or someone else with a more advanced knowledge of compilers than my current self can write up a better system. And that is the point of all these code moves in recent times, so in the event such a thing would occur it can easily be planted in and used instead.
00:35
So for optimization, do not ruin my own code and just keep it in pure Java. The recompiler can handle optimization so that non-portable magical constructs are not required to be used.
16:24
Ok, so every class including inner classes will always refer to outer classes. The specified class is called C (may be this), and the outer class is zero then it is top level, an interface, a local, or an anonymous class.