Send event on thread death.

src/context/context.rs

@@ -25,6 +25,7 @@ use crate::syscall::error::{Error, Result, EAGAIN, ESRCH};
 
 use super::{
     empty_cr3,
+    file::FileDescription,
     memory::{AddrSpaceWrapper, GrantFileRef},
 };
 
@@ -120,6 +121,9 @@ pub struct Context {
     pub being_sigkilled: bool,
     pub fmap_ret: Option<Frame>,
 
+    // TODO: id can reappear after wraparound?
+    pub owner_proc_id: Option<NonZeroUsize>,
+
     // TODO: Temporary replacement for existing kernel logic, replace with capabilities!
     pub ens: SchemeNamespace,
     pub euid: u32,
@@ -145,9 +149,9 @@ pub struct SignalState {
 }
 
 impl Context {
-    pub fn new() -> Result<Context> {
+    pub fn new(owner_proc_id: Option<NonZeroUsize>) -> Result<Context> {
         static DEBUG_ID: AtomicU32 = AtomicU32::new(1);
-        let this = Context {
+        let this = Self {
             debug_id: DEBUG_ID.fetch_add(1, Ordering::Relaxed),
             sig: None,
             status: Status::HardBlocked {
@@ -172,6 +176,7 @@ impl Context {
             userspace: false,
             fmap_ret: None,
             being_sigkilled: false,
+            owner_proc_id,
 
             ens: 0.into(),
             euid: u32::MAX,

src/context/mod.rs

@@ -2,6 +2,8 @@
 //!
 //! For resources on contexts, please consult [wikipedia](https://en.wikipedia.org/wiki/Context_switch) and  [osdev](https://wiki.osdev.org/Context_Switching)
 
+use core::num::NonZeroUsize;
+
 use alloc::{borrow::Cow, collections::BTreeSet, sync::Arc};
 
 use spin::{RwLock, RwLockReadGuard, RwLockWriteGuard};
@@ -68,7 +70,8 @@ pub use self::arch::empty_cr3;
 static CONTEXTS: RwLock<BTreeSet<ContextRef>> = RwLock::new(BTreeSet::new());
 
 pub fn init() {
-    let mut context = Context::new().expect("failed to create kmain context");
+    let owner = None; // kmain not owned by any fd
+    let mut context = Context::new(owner).expect("failed to create kmain context");
     context.sched_affinity = LogicalCpuSet::empty();
     context.sched_affinity.atomic_set(crate::cpu_id());
     context.name = Cow::Borrowed("kmain");
@@ -140,11 +143,15 @@ impl PartialEq for ContextRef {
 impl Eq for ContextRef {}
 
 /// Spawn a context from a function.
-pub fn spawn(userspace_allowed: bool, func: extern "C" fn()) -> Result<Arc<RwSpinlock<Context>>> {
+pub fn spawn(
+    userspace_allowed: bool,
+    owner_proc_id: Option<NonZeroUsize>,
+    func: extern "C" fn(),
+) -> Result<Arc<RwSpinlock<Context>>> {
     let stack = Kstack::new()?;
 
-    let context_lock =
-        Arc::try_new(RwSpinlock::new(Context::new()?)).map_err(|_| Error::new(ENOMEM))?;
+    let context_lock = Arc::try_new(RwSpinlock::new(Context::new(owner_proc_id)?))
+        .map_err(|_| Error::new(ENOMEM))?;
 
     CONTEXTS
         .write()