sweep_node uses 100% CPU if cable accidentally unplugged. - Githubissues

scanse / sweep-ros

Scanse Sweep ROS Driver and Node

MIT License

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sweep_node uses 100% CPU if cable accidentally unplugged. #11

Closed sevenbitbyte closed 7 years ago

sevenbitbyte commented 7 years ago

When unexpectedly unplugged the sweep_node consumes 100% of CPU cycles and reports no errors. Use on autonomous unmanned systems will require improved failure reporting. Ideally this can be done without spiking CPU usage as well. Finally I would like to achieve failure recovery, so I can just plug the sensor back in and it starts back up smoothly(assuming /dev path stays the same).

Repro steps:

Plugin sensor
Start a system monitor: htop
Start sweep_node roslaunch sweep_ros sweep.launch
Wait until scans are collected(1-5s): rostopic hz /pc2
Unplug sensor

Observed result

CPU usage goes from ~0.1% to over 90%
No error messages in /rosout or log files
Node stops publishing to /pc2 topic

Expected result

Error message indicating some form of sensor failure/read timeout
CPU usage unchanged

sevenbitbyte commented 7 years ago

Looks like the CPU spike culprit: https://github.com/scanse/sweep-sdk/blob/master/libsweep/src/unix/serial.cc#L332