devices: event_loop: delete hung-up events
When a file descriptor is returned from the poll context that has the
hungup flag set, it should no longer be polled. Remove it from both the
poll context and the map of handlers when hangup occurs.
Additionally, instead of stopping the whole event loop when an event
handler error occurs, just remove the failing event handler from the
watched set and continue. This should improve robustness of the USB
controller emulation.
BUG=chromium:1278424
TEST=Share USB device with Crostini via vmc, then physically unplug
Change-Id: Iccaae0ea24b43d0b5e593ca2fe4418eb3892300a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3335302
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
diff --git a/devices/src/utils/event_loop.rs b/devices/src/utils/event_loop.rs
index 2a11701..a8fed3a 100644
--- a/devices/src/utils/event_loop.rs
+++ b/devices/src/utils/event_loop.rs
@@ -99,39 +99,40 @@
}
};
for event in &events {
- if event.token().as_raw_descriptor() == stop_evt.as_raw_descriptor() {
+ let fd = event.token().as_raw_descriptor();
+ if fd == stop_evt.as_raw_descriptor() {
return;
+ }
+
+ let mut locked = fd_callbacks.lock();
+ let weak_handler = match locked.get(&fd) {
+ Some(cb) => cb.clone(),
+ None => {
+ warn!("callback for fd {} already removed", fd);
+ continue;
+ }
+ };
+
+ // If the file descriptor is hung up, remove it after calling the handler
+ // one final time.
+ let mut remove = event.hungup();
+
+ if let Some(handler) = weak_handler.upgrade() {
+ // Drop lock before triggering the event.
+ drop(locked);
+ if let Err(e) = handler.on_event() {
+ error!("removing event handler due to error: {:#}", e);
+ remove = true;
+ }
+ locked = fd_callbacks.lock();
} else {
- let fd = event.token().as_raw_descriptor();
- let mut locked = fd_callbacks.lock();
- let weak_handler = match locked.get(&fd) {
- Some(cb) => cb.clone(),
- None => {
- warn!("callback for fd {} already removed", fd);
- continue;
- }
- };
- match weak_handler.upgrade() {
- Some(handler) => {
- // Drop lock before triggering the event.
- drop(locked);
- match handler.on_event() {
- Ok(()) => {}
- Err(e) => {
- error!("event loop stopping due to handle event error: {:#}", e);
- fail_handle.fail();
- return;
- }
- };
- }
- // If the handler is already gone, we remove the fd.
- None => {
- let _ = poll_ctx.delete(&Descriptor(fd));
- if locked.remove(&fd).is_none() {
- error!("fail to remove handler for file descriptor {}", fd);
- }
- }
- };
+ // If the handler is already gone, we remove the fd.
+ remove = true;
+ }
+
+ if remove {
+ let _ = poll_ctx.delete(&event.token());
+ let _ = locked.remove(&fd);
}
}
}
