state: store compositor pid

src/compositor.rs

@@ -199,7 +199,8 @@ fn start_compositor2(
     test_future: Option<TestFuture>,
     caps_thread: Option<PrCapsThread>,
 ) -> Result<(), CompositorError> {
-    log::info!("pid = {}", uapi::getpid());
+    let pid = uapi::getpid();
+    log::info!("pid = {pid}");
     log::info!("version = {VERSION}");
     if did_elevate_scheduler() {
         log::info!("Running with elevated scheduler: SCHED_RR");
@@ -224,6 +225,7 @@ fn start_compositor2(
     let crit_ids = Rc::new(CritMatcherIds::default());
     let eventfd_cache = EventfdCache::new(&ring, &engine);
     let state = Rc::new(State {
+        pid,
         kb_ctx,
         backend: CloneCell::new(Rc::new(DummyBackend)),
         forker: Default::default(),

src/state.rs

@@ -145,10 +145,12 @@ use {
         time::Duration,
     },
     thiserror::Error,
-    uapi::OwnedFd,
+    uapi::{OwnedFd, c},
 };
 
 pub struct State {
+    #[expect(dead_code)]
+    pub pid: c::pid_t,
     pub kb_ctx: KbvmContext,
     pub backend: CloneCell<Rc<dyn Backend>>,
     pub forker: CloneCell<Option<Rc<ForkerProxy>>>,