Failed init services when running device_container_node in a two core computer

[POtaoPereiraRosen]

Describe the bug Failed init services when running device_container_node in a two core computer

To Reproduce When launching device_container_node (canopen_core/launch/canopen.launch.py)

• in a two core computer
• with two motor nodes
• when calling the init service of these two nodes simultaneously Then:
• both services fail (after a timeout of 5 seconds, they return success=false)
• the publishers of the topic joint_states, for both motors, do not publish any data for 5 seconds (after the call of the init services)

Expected behavior This behaviour does not exist when device_container_node is launched in a virtual machine with 8 processors. But our target platform is a computer with 2 cores, and there the faulty behaviour (described above) occurs. The faulty behaviour also occurs, in a virtual machine setup with 2 processors.

Setup:

• Device: Virtual machine with 2 processors or a computer with two cores
• OS: Ubuntu 22
• ROS-Distro: Humble

[hellantos]

@POtaoPereiraRosen this could be because three threads are necessary for this. Does it work if you initialise sequencially?

[POtaoPereiraRosen]

@ipa-cmh Yes, when starting sequentially, it works (i.e., if I wait for the reply of the init-service of motor 1, and then call the init-service of motor 2, then it works). In your question, you referred to the need of three threads: I am guessing you meant hardware-threads/cores/CPUs/processors. Out of curiosity, why are three cores required?

[hellantos]

One thread runs the canopen loop, an one per driver.