OSDev.org

mmiikkee12 wrote:OK, so I've pretty much decided that I can't do my own kernel, it's just too much work for one person. (I used to have 2 other developers, but they ran off and created a separate project with different (and somewhat pointless imo) goals.) However, I'd still like to do some kind of OS work, so does anyone need a developer? Here's what I'd like an OS to have for me to join it:
- Not aiming for compatibility with other major OSes - if I want to run Linux apps, why not just run Linux?
- A GUI-based OS - I have a graphics card, I'd like to use it (and I don't mean a bunch of terminals/command prompt windows floating around on a desktop with nothing resembling a menu.) Note that I don't mean you already have to have a working GUI, but "completely text-based interface" shouldn't be anywhere in your list of goals.
- Should be open to new ideas - I won't try to force all of my design ideas onto your OS, but if I see something that could be implemented better chances are I'll say something.
- Must be x86 or x86-64, and written in C or C++ (I prefer C++).
- Must be compileable on x86 Linux with standard GNU tools.

(If the above seems overly aggressive, it wasn't meant to be. I just don't want to contribute to a project I don't like

I'm thinking of downgrading my kernel to C from C++.

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MessiahAndrw wrote:I can't point to functions within C++ classes making vtables practically useless.

It's sometimes hard to define what should go into a struct and what should go into a class.

And the overhead of calling a function is much lower than calling functions between classes since you don't have the overhead of saving and changing the class states (although in reality this is only a few extra instructions).

Against C++:
I can't point to functions within C++ classes making vtables practically useless. I know I can use interfaces but only if I know the function I want to be called (and it's parameters and make it's the same function in every class) and inherit from the interface. Mostly used for IRCs and timer events.

Against C++:
It's sometimes hard to define what should go into a struct and what should go into a class.

For C++:
... Inheritance is a god send (devices and drivers all inherit from a base device ...

For now I'll probably stick with C++.

The more I move out of the kernel the simpler the kernel core becomes making C (and representing processes and devices as simple memory structures) seem feasible again. And the overhead of calling a function is much lower than calling functions between classes since you don't have the overhead of saving and changing the class states (although in reality this is only a few extra instructions).

typedef struct
{
    int pid;
    ...
} process_t;

void kill_process(process_t *p, int signal);

some_process.kill(signal);

Process::kill(&some_process, signal);

mmiikkee12 wrote:OK, so I've pretty much decided that I can't do my own kernel, it's just too much work for one person. (I used to have 2 other developers, but they ran off and created a separate project with different (and somewhat pointless imo) goals.) However, I'd still like to do some kind of OS work, so does anyone need a developer? Here's what I'd like an OS to have for me to join it:
- Not aiming for compatibility with other major OSes - if I want to run Linux apps, why not just run Linux?
- A GUI-based OS - I have a graphics card, I'd like to use it (and I don't mean a bunch of terminals/command prompt windows floating around on a desktop with nothing resembling a menu.) Note that I don't mean you already have to have a working GUI, but "completely text-based interface" shouldn't be anywhere in your list of goals.
- Should be open to new ideas - I won't try to force all of my design ideas onto your OS, but if I see something that could be implemented better chances are I'll say something.
- Must be x86 or x86-64, and written in C or C++ (I prefer C++).
- Must be compileable on x86 Linux with standard GNU tools.

(If the above seems overly aggressive, it wasn't meant to be. I just don't want to contribute to a project I don't like

mmiikkee12 wrote:

Against C++:
It's sometimes hard to define what should go into a struct and what should go into a class.

My general rule: if it has to be in a specific order, use a struct. If not, use a class. (I know it doesn't matter, but it helps me think.)

Wave wrote:

mmiikkee12 wrote:

Against C++:
It's sometimes hard to define what should go into a struct and what should go into a class.

My general rule: if it has to be in a specific order, use a struct. If not, use a class. (I know it doesn't matter, but it helps me think.)

If it has functions as members it goes into a class. If it doesn't you probably have functions outside it to manipulate its member variables. If you have that, move those functions inside the struct and make it a class.

That was one of my original plans when I switched to C++. But then I started thinking... how would you do that without having a monolithic, non-modular kernel? Unless you can think of a way to load classes/objects from files.

Fate wrote:Also, one would need to keep in mind the extra overhead method calls into those objects would have.......