Analog input devices cause Mumble to lag/freeze

[Krzmbrzl]

Description

If Mumble is running on a computer that has an analog input device (such as a Joystick, Racing pedals or similar), it will just completely freeze up or at least get very laggy.

CPU usage in such cases spikes as well.

Steps to reproduce

1. Start Mumble
2. Connect analog input device

Mumble version

1.4 and newer

Mumble component

Client

OS

Windows

Reproducible?

Yes

Additional information

It seems like this issue is more or less directly correlated to the switch towards RawInput on Windows (#6602). The assumed cause for the freeze is that the analog input device is just continuously generating input events, which Mumble receives and posts into the Qt event queue. However, the events are sent faster than Qt's event queue (and the respective handlers we have attached to it) can process. This leads to a congested event queue that in turn leads to a laggy application. Meanwhile the program is extremely busy discarding irrelevant input events, consuming a lot of CPU time while doing so.

Related issues:

• Freezing with Simracing Pedals #6642
• 1.4.230 UI hangs/unresponsive #5631
• High Power usage causing serious lag #6054

Also related:

• https://forums.mumble.info/topic/14467-14-conflict-with-flight-control-rudder-pedals/

Relevant log output

No response

Screenshots

No response