feat(domain): add ThreadTable with spawn, get, destroy, and process filtering

crates/domain/src/error.rs

@@ -15,4 +15,6 @@ pub enum KernelError {
     TooManyThreadsInProcess,
     TooManyProcesses,
     InvalidStateTransition(ThreadId),
+    InvalidThread(ThreadId),
+    TooManyThreads,
 }

crates/domain/src/thread/mod.rs

@@ -141,3 +141,66 @@ impl Thread {
         }
     }
 }
+
+pub const MAX_THREADS: usize = 256;
+
+pub struct ThreadTable {
+    threads: [Option<Thread>; MAX_THREADS],
+}
+
+impl ThreadTable {
+    pub fn new() -> Self {
+        Self {
+            threads: [const { None }; MAX_THREADS],
+        }
+    }
+
+    pub fn spawn(
+        &mut self,
+        process: ProcessId,
+        priority: Priority,
+        time_slice: TimeSlice,
+        core_affinity: Option<CoreId>,
+    ) -> Result<ThreadId, KernelError> {
+        let idx = self
+            .threads
+            .iter()
+            .position(|s| s.is_none())
+            .ok_or(KernelError::TooManyThreads)?;
+
+        let id = ThreadId::from_raw(idx as u16);
+        self.threads[idx] = Some(Thread::new(id, process, priority, time_slice, core_affinity));
+        Ok(id)
+    }
+
+    pub fn get(&self, id: ThreadId) -> Result<&Thread, KernelError> {
+        let idx = id.raw() as usize;
+        self.threads
+            .get(idx)
+            .and_then(|s| s.as_ref())
+            .ok_or(KernelError::InvalidThread(id))
+    }
+
+    pub fn get_mut(&mut self, id: ThreadId) -> Result<&mut Thread, KernelError> {
+        let idx = id.raw() as usize;
+        self.threads
+            .get_mut(idx)
+            .and_then(|s| s.as_mut())
+            .ok_or(KernelError::InvalidThread(id))
+    }
+
+    pub fn destroy(&mut self, id: ThreadId) -> Result<Thread, KernelError> {
+        let idx = id.raw() as usize;
+        self.threads
+            .get_mut(idx)
+            .and_then(|s| s.take())
+            .ok_or(KernelError::InvalidThread(id))
+    }
+
+    pub fn threads_for_process(&self, process: ProcessId) -> impl Iterator<Item = &Thread> {
+        self.threads
+            .iter()
+            .filter_map(|s| s.as_ref())
+            .filter(move |t| t.process() == process)
+    }
+}

crates/domain/src/thread/tests.rs

@@ -156,3 +156,58 @@ fn time_slice_mut_ticks() {
     let expired = t.time_slice_mut().tick();
     assert!(!expired);
 }
+
+// --- ThreadTable tests ---
+
+#[test]
+fn table_spawn_and_lookup() {
+    let mut table = ThreadTable::new();
+    let id = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    let t = table.get(id).unwrap();
+    assert_eq!(t.id(), id);
+    assert_eq!(t.process(), process(0));
+}
+
+#[test]
+fn table_spawn_returns_unique_ids() {
+    let mut table = ThreadTable::new();
+    let a = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    let b = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    assert_ne!(a, b);
+}
+
+#[test]
+fn table_destroy_then_get_fails() {
+    let mut table = ThreadTable::new();
+    let id = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    table.destroy(id).unwrap();
+    assert!(table.get(id).is_err());
+}
+
+#[test]
+fn table_threads_for_process_filters() {
+    let mut table = ThreadTable::new();
+    table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    table.spawn(process(1), prio(10), time_slice(), None).unwrap();
+    table.spawn(process(0), prio(5), time_slice(), None).unwrap();
+
+    let count = table.threads_for_process(process(0)).count();
+    assert_eq!(count, 2);
+}
+
+#[test]
+fn table_get_mut_allows_state_transition() {
+    let mut table = ThreadTable::new();
+    let id = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    table.get_mut(id).unwrap().set_running(core(0)).unwrap();
+    assert!(matches!(table.get(id).unwrap().state(), ThreadState::Running(_)));
+}
+
+#[test]
+fn table_destroy_reuses_slot() {
+    let mut table = ThreadTable::new();
+    let id = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    table.destroy(id).unwrap();
+    let new_id = table.spawn(process(0), prio(10), time_slice(), None).unwrap();
+    assert_eq!(id, new_id);
+}