fn poll()

in sdk/core/azure_core/src/task/standard_spawn.rs [39:78]
31 lines of code
4 McCabe index (conditional complexity)

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        let mut join_state = self.join_state.lock().map_err(|e| {
            debug!("Failed to lock join state: {}", e);
            Box::new(crate::Error::message(
                crate::error::ErrorKind::Other,
                format!("Thread panicked: {:?}", e),
            )) as Box<dyn std::error::Error + Send>
        })?;

        // Join handle is present, so we can check if the thread has finished
        // and take the handle if it has.
        // This is safe because we are holding the lock on the join state.
        // We can safely take the handle and join it without blocking.
        // This allows us to retrieve the terminal state of the thread.
        if join_state.thread_finished {
            // Thread is finished, so we can safely take the handle
            let Some(join_handle) = join_state.join_handle.take() else {
                // The join handle was already removed from the state, we know we're done.
                return Poll::Ready(Ok(()));
            };

            // Since we know the thread is finished, we can safely take the handle
            // and join it. This allows us to retrieve the terminal state of the thread.
            //
            // Technically this might block (because the `thread_finished` flag
            // is set before the thread *actually* finishes), but it should be negligible.
            match join_handle.join() {
                Ok(_) => Poll::Ready(Ok(())),
                Err(e) => Poll::Ready(Err(Box::new(crate::Error::message(
                    crate::error::ErrorKind::Other,
                    format!("Thread panicked: {:?}", e),
                )) as Box<dyn std::error::Error + Send>)),
            }
        } else {
            // Thread is still running, so we need to register the waker
            // for when it completes.
            join_state.waker = Some(cx.waker().clone());
            Poll::Pending
        }
    }