Function writer_handler

vga_driver/src/main.rs:513–560

(
    writer: Arc<RwLock<Writer<Text80x25>>>,
    comm_handle: CommHandle)

}

fn writer_handler(
    writer: Arc<RwLock<Writer<Text80x25>>>,
    comm_handle: CommHandle) {

    loop {
        match syscalls::receive(&comm_handle) {
            Ok(syscalls::Message::Long(
                message::WRITE,
                MessageData::Value(length),
                MessageData::MemoryHandle(data_handle))) => {

                let data = data_handle.as_slice::<u8>(length as usize);
                writer.write().write_string(data);

                // Done, send reply
                syscalls::send(&comm_handle,
                               syscalls::Message::Short(
                                   message::OK, 0, 0));
            },
            Ok(syscalls::Message::Short(
                message::CHAR, ch, _)) => {

                let s : [u8; 1] = [ch as u8];
                writer.write().write_string(&s);
            },
            Ok(message) => {
                // Unknown message => Return error
                syscalls::send(&comm_handle,
                               syscalls::Message::Short(
                                   message::ERROR_UNKNOWN_MESSAGE, 0, 0));
            },
            Err(syscalls::SYSCALL_ERROR_RECV_BLOCKING) => {
                // Waiting for a message
                // => Send an error message
                syscalls::send(&STDIN,
                               Message::Short(
                                   message::ERROR, 0, 0));
                // Wait and try again
                syscalls::thread_yield();
            },
            Err(code) => {
                debug_println!("[vga] Receive error {}", code);
                // Wait and try again
                syscalls::thread_yield();
            }
        }
    }
}