The async queue default policy has been to trigger an async overflow error when the async queue overflows. The new default policy is to ignore async queue overflows.

The async queue plays an important role in how UI events are processed on Unix. Sometimes so many events come in at once that the async queue runs out of space and can not add more entries. This results in the runtime error “Async Queue has overflowed” that displays a debugger. Generally, developers simply close the debugger and continue with what they were doing.

The async queue was undersized, which we have changed for 9.1. But additionally, we added a new default policy that async overflows are ignored by default.

While this is the new default policy, it is customizable and the section below describes how to restore the old behavior if you are making use of the async queue in your application and dropping events is not an option.

In the future, we will be building a more elastic async queue that can adapt to the situation.

To restore the old behavior of triggering an async overflow error, execute the following code on startup of your application.