src/ipc/server.rs

use crate::callback::CallbackSubscription;
use crate::callback::SubscribableCallback;
use crate::syscalls;
use core::slice;

const DRIVER_NUMBER: usize = 0x10000;

mod ipc_commands {
    pub const REGISTER_SERVICE: usize = 0;
    pub const NOTIFY_CLIENT: usize = 1;
}

pub struct IpcServerCallback<CB> {
    callback: CB,
}

impl<CB> IpcServerCallback<CB> {
    pub fn new(callback: CB) -> Self {
        IpcServerCallback { callback }
    }
}

impl<CB: FnMut(usize, usize, &mut [u8])> SubscribableCallback for IpcServerCallback<CB> {
    fn call_rust(&mut self, arg0: usize, arg1: usize, arg2: usize) {
        // FIXME: This is unsafe because IpcServerCallback can be subscribed on any driver
        let mut v = unsafe { slice::from_raw_parts_mut(arg2 as *mut u8, arg1) };
        (self.callback)(arg0, arg1, &mut v);
    }
}

pub fn notify_client(pid: usize) {
    unsafe { syscalls::command(DRIVER_NUMBER, pid, ipc_commands::NOTIFY_CLIENT, 0) };
}

pub struct IpcServerDriver;

impl IpcServerDriver {
    pub fn start<CB>(callback: &mut IpcServerCallback<CB>) -> Result<CallbackSubscription, isize>
    where
        IpcServerCallback<CB>: SubscribableCallback,
    {
        syscalls::subscribe(DRIVER_NUMBER, ipc_commands::REGISTER_SERVICE, callback)
    }
}