Event system

kernel/src/events/mod.rs

@@ -1,12 +1,63 @@
+use core::mem::discriminant;
+
+use lazy_static::lazy_static;
+
+#[macro_use]
+mod types;
+use spin::Mutex;
+pub use types::*;
 
 
+const MAX_EVENT_LISTENERS: usize = 255;
 
-pub struct KernelEventHandler {
+lazy_static!(
+    pub static ref EVENTMAN: Mutex<EventManager> = Mutex::new(EventManager::new());
+);
 
 
+pub struct EventManager {
+    listeners: [Option<EventManagerEntry>; MAX_EVENT_LISTENERS],
+    listener_count: usize,
+}
+
+type EventListenerFunc = fn(ev: &Event) -> Result<(), ()>;
+pub struct EventManagerEntry {
+    pub func: EventListenerFunc,
+    pub typ: Event
+}
+
+
+const ARRAY_REPEAT_VALUE: Option<EventManagerEntry> = None;
+
+impl EventManager {
+    pub fn new() -> Self {
+        Self {
+            listeners: [ARRAY_REPEAT_VALUE; MAX_EVENT_LISTENERS],
+            listener_count: 0
+        }
+    }
+
+    pub fn dispatch(&self, ev: &Event){
+        for listener in &self.listeners {
+            if let Some(l) = listener {
+                if discriminant(ev) == discriminant(&l.typ) {
+                    // TODO: Do something with the result
+                    let _ = (l.func)(ev);
+                }
+            }
+        }
+    }
+
+    pub fn add_listener(&mut self, typ: Event, func: EventListenerFunc) {
+        self.listeners[self.listener_count] = Some(EventManagerEntry {
+            func, typ
+        })
+    }
+    
+    #[allow(dead_code)]
+    pub fn remove_listener(&mut self, _: &str) {
+        todo!()
+    }
+
 }
 
-impl KernelEventHandler {
-
-
-}

kernel/src/events/types.rs

@@ -0,0 +1,19 @@
+use pc_keyboard::DecodedKey;
+
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum Event {
+    TimerInterrupt(Option<usize>), // trash unused value
+    Ps2KeyPress(Option<DecodedKey>)
+}
+
+#[macro_export]
+macro_rules! get_event_value {
+    ($typ:pat, $ev:expr) => {
+        match $ev {
+            $typ(v) => v.unwrap(),
+            _ => panic!("Bad event value")
+        }
+    };
+}
+

kernel/src/interrupts/handlers/mod.rs

@@ -1,5 +1,5 @@
 use x86_64::structures::idt::{InterruptStackFrame, PageFaultErrorCode};
-use crate::interrupts::InterruptIndex;
+use crate::{events::EVENTMAN, interrupts::InterruptIndex};
 
 mod ps2_keyboard;
 
@@ -12,6 +12,7 @@ pub extern "x86-interrupt" fn breakpoint(sf: InterruptStackFrame){
 pub extern "x86-interrupt" fn timer_interrupt(_: InterruptStackFrame){
     //log::debug!("INT: TIMER\n{:#?}", sf);
     // print!(".");
+    EVENTMAN.lock().dispatch(&crate::events::Event::TimerInterrupt(None));
     unsafe {
         super::PICS.lock()
             .notify_end_of_interrupt(InterruptIndex::Timer as u8);

kernel/src/interrupts/handlers/ps2_keyboard.rs

@@ -1,6 +1,9 @@
+use pc_keyboard::DecodedKey;
 use x86_64::structures::idt::InterruptStackFrame;
 
-use crate::interrupts::PICS;
+use crate::{events::EVENTMAN, interrupts::PICS};
+
+pub struct Ps2KbPressEvent(DecodedKey);
 
 pub extern "x86-interrupt" fn ps2_kb_int(_sf: InterruptStackFrame){
     use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
@@ -20,12 +23,7 @@ pub extern "x86-interrupt" fn ps2_kb_int(_sf: InterruptStackFrame){
     let scancode: u8 = unsafe { port.read() };
     if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
         if let Some(key) = keyboard.process_keyevent(key_event) {
-            if false {
-                match key {
-                    DecodedKey::Unicode(character) => print!("{}", character),
-                    DecodedKey::RawKey(key) => print!("{:?}", key),
-                }
-            }
+            EVENTMAN.lock().dispatch(&crate::events::Event::Ps2KeyPress(Some(key)));
         }
     }
     unsafe {

kernel/src/interrupts/mod.rs

@@ -1,5 +1,6 @@
 use pic8259::ChainedPics;
-use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
+use x86_64::structures::idt::InterruptDescriptorTable;
+
 
 mod handlers;
 

kernel/src/lib.rs

@@ -1,17 +1,18 @@
 #![no_std]
 #![no_main]
 #![feature(abi_x86_interrupt)]
+#![feature(associated_type_defaults)]
 
-use multiboot2::BootInformationHeader;
-use x86_64::registers::control::Cr3;
+use events::EVENTMAN;
 
-use crate::mem::FrameAllocator;
+use crate::events::Event;
 
 #[macro_use]
 mod logger;
 mod interrupts;
 mod gdt;
 mod utils;
+#[macro_use]
 mod events;
 mod mem;
 
@@ -24,15 +25,16 @@ extern "C" fn kmain(mb2_info_addr: usize) -> ! {
     gdt::init();
     interrupts::init_idt();
     let mem_info = mem::MemInfo::load(mb2_info_addr);
-    let mut alloc = mem::area_frame_alloc::AreaFrameAllocator::new(mem_info);
-    
-    for i in 0.. {
-    if let None = alloc.allocate_frame() {
-        println!("allocated {} frames", i);
-        break;
-    }
-}
+    let mut _alloc = mem::area_frame_alloc::AreaFrameAllocator::new(mem_info);
     
+    EVENTMAN.lock().add_listener(events::Event::Ps2KeyPress(None), |k| {
+        let Event::Ps2KeyPress(v) = k else {panic!()};
+
+        log::debug!("Keypress event received! ({:?})", v.unwrap());
+        Ok(())
+    });
+
+
     // let (level_4_page_table, _) = Cr3::read();
     // println!("Level 4 page table at: {:?}", level_4_page_table.start_address());
 

kernel/src/mem/area_frame_alloc.rs

@@ -1,5 +1,3 @@
-use core::slice::Iter;
-
 use super::{Frame, FrameAllocator, MemInfo, MemoryAreaIter};
 use multiboot2::MemoryArea;
 

kernel/src/mem/mod.rs

@@ -1,6 +1,6 @@
-use core::{alloc::{GlobalAlloc, Layout}, ops::Deref};
+use core::alloc::{GlobalAlloc, Layout};
 
-use multiboot2::{BootInformation, BootInformationHeader, MemoryArea, MemoryAreaType, MemoryMapTag, TagTrait};
+use multiboot2::{BootInformationHeader, MemoryArea, MemoryAreaType, MemoryMapTag, TagTrait};
 
 pub mod area_frame_alloc;
 
@@ -8,8 +8,8 @@ pub mod area_frame_alloc;
 static GLOBAL_ALLOCATOR: DummyAlloc = DummyAlloc;
 pub struct DummyAlloc;
 unsafe impl GlobalAlloc for DummyAlloc {
-    unsafe fn alloc(&self, layout: Layout) -> *mut u8 { 0 as *mut u8 }
-    unsafe fn dealloc(&self, ptr: *mut u8, _: Layout) {}
+    unsafe fn alloc(&self, _: Layout) -> *mut u8 { 0 as *mut u8 }
+    unsafe fn dealloc(&self, _ptr: *mut u8, _: Layout) {}
 }
 
 pub const PAGE_SIZE: usize = 4096;
@@ -26,6 +26,7 @@ impl Frame {
     }
 }
 
+#[allow(dead_code)]
 pub trait FrameAllocator {
     fn allocate_frame(&mut self) -> Option<Frame>;
     fn deallocate_frame(&mut self, frame: Frame);
@@ -83,7 +84,7 @@ impl MemInfo {
         let boot_info = unsafe {
             multiboot2::BootInformation::load(mb_ptr as *const BootInformationHeader).unwrap()
         };
-        let mmap_tag = boot_info.memory_map_tag().unwrap().clone();
+        let mmap_tag = boot_info.memory_map_tag().unwrap();
 
         // log::debug!("Memory areas:");
         // for area in mmap_tag.memory_areas() {