io_uring: add timeout_external

src/io_uring/ops/timeout_external.rs

@@ -0,0 +1,98 @@
+use {
+    crate::{
+        io_uring::{
+            ops::timeout::timespec64,
+            sys::{io_uring_sqe, IORING_OP_TIMEOUT, IORING_TIMEOUT_ABS},
+            IoUring, IoUringData, IoUringError, IoUringTaskId, Task,
+        },
+        utils::oserror::OsError,
+    },
+    std::{cell::Cell, rc::Rc},
+    uapi::c,
+};
+
+pub trait TimeoutCallback {
+    fn completed(self: Rc<Self>, res: Result<(), OsError>, data: u64);
+}
+
+pub struct PendingTimeout {
+    data: Rc<IoUringData>,
+    shared: Rc<TimeoutExternalTaskShared>,
+    id: IoUringTaskId,
+}
+
+impl Drop for PendingTimeout {
+    fn drop(&mut self) {
+        if self.shared.id.get() != self.id {
+            return;
+        }
+        self.shared.callback.take();
+        self.data.cancel_task(self.id);
+    }
+}
+
+#[derive(Default)]
+struct TimeoutExternalTaskShared {
+    id: Cell<IoUringTaskId>,
+    callback: Cell<Option<Rc<dyn TimeoutCallback>>>,
+}
+
+#[derive(Default)]
+pub struct TimeoutExternalTask {
+    timespec: timespec64,
+    shared: Rc<TimeoutExternalTaskShared>,
+    data: u64,
+}
+
+impl IoUring {
+    #[expect(dead_code)]
+    pub fn timeout_external(
+        &self,
+        timeout_nsec: u64,
+        callback: Rc<dyn TimeoutCallback>,
+        data: u64,
+    ) -> Result<PendingTimeout, IoUringError> {
+        self.ring.check_destroyed()?;
+        let mut pw = self.ring.cached_timeouts_external.pop().unwrap_or_default();
+        pw.shared.id.set(self.ring.id_raw());
+        pw.shared.callback.set(Some(callback));
+        pw.timespec = timespec64 {
+            tv_sec: (timeout_nsec / 1_000_000_000) as _,
+            tv_nsec: (timeout_nsec % 1_000_000_000) as _,
+        };
+        pw.data = data;
+        let pending = PendingTimeout {
+            data: self.ring.clone(),
+            shared: pw.shared.clone(),
+            id: pw.shared.id.get(),
+        };
+        self.ring.schedule(pw);
+        Ok(pending)
+    }
+}
+
+unsafe impl Task for TimeoutExternalTask {
+    fn id(&self) -> IoUringTaskId {
+        self.shared.id.get()
+    }
+
+    fn complete(self: Box<Self>, ring: &IoUringData, res: i32) {
+        if let Some(pr) = self.shared.callback.take() {
+            let res = if res == -c::ETIME {
+                Ok(())
+            } else {
+                map_err!(res).map(drop)
+            };
+            pr.completed(res, self.data);
+        }
+        ring.cached_timeouts_external.push(self);
+    }
+
+    fn encode(&self, sqe: &mut io_uring_sqe) {
+        sqe.opcode = IORING_OP_TIMEOUT;
+        sqe.u2.addr = &self.timespec as *const _ as _;
+        sqe.len = 1;
+        sqe.u3.timeout_flags = IORING_TIMEOUT_ABS;
+        sqe.u1.off = 0;
+    }
+}