Hans_ wrote:
In theory it's all possible simply because we know that humans can do it.
I think that's one of the factors that is driving me on.
bloodline wrote:
In an MP OS, one would define that the pointer returned by AllocMem() is for the use of the calling task only.
In AmigaOS the pointer returned by AllocMem() is free for any task to use, this is defined behaviour.
Okay, so Amiga software expects to be able to use pointers defined by other Amiga software. So there is almost a pool of memory pointers. Can we put these memory pointers in an OS controlled environment and control which programs we'd like to use these pointers?
In the place of the pointers in the application code we put a 'port' to the shared pointer area. When a program then wants to access the data or instruction in memory a request to the OS goes to through that port. The OS then uses the pointer itself, and the outcome of this action is stored in a 'quarantine' area in memory. The OS then tries to determine (based on past experience and/or user preference) whether that data should be given to the application.
Way I see it, if a program causes a computer to crash, we should be able to determine when it crashed, and what was the last value (data or instruction) to be passed for processing, right? If we can do this, we have options when it comes to crash protection (which is the main benefit of MP IMO), as long as we catch the value before it is passed for execution (or maybe before storage in its designated memory location).
Or maybe we don't have those options... can you give me typical low level examples of what causes a computer to crash?
Hans_ wrote:
What exactly is wrong with allowing old software to be fully-allocated in shared-memory and run in a sand-box?
I want to see the AmigaOS 3.1 API succeed as much as possible as I see it as a bridge between different Amiga-based OSs. A sandbox is okay, but it would split the community again as there would be a new 'native' API. AROS is in the unique position to bring the Amiga world together, and I don't want to see it lose that.
Hans_ wrote:
Henry is suggesting getting the compiler to insert the MEMF_SHARED flag (and/or whatever else woulld be used) whenever it's necessary. The problem is that finding out when it's necessary is incredibly complex.
Correct, I'm advocating making memory private by default. The 'finding out when sharing is neccessary' task I am trying to pass to humans.
bloodline wrote:
He needs to understand that the messages and message passing are not the problem, it's the contents that's the problem.
So I would prefer it if we could keep a examples as simple as possible.
bloodline, I appreciate your approach here. I agree it is best to keep the information you are all giving me as simple as possible, I do feel like I am slowly getting my head around the larger issues here, thank you for your patience (and everyone elses). The thing is I'm finding this discussion rather interesting, and as I'm getting more information it's throwing up more questions and possibilities in my head. Please forgive/understand my curiosity!
