fix for #666: network issues for one device impacts data gathering of…

[marcb-dame]

network issues for one device impacts data gathering of all devices. Fixes #666

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PR Checklist

Please check if your PR fulfills the following requirements:

• I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• I am not introducing a new dependency (add notes below if you are)
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Testing Instructions

You need to have a (mock) device with network issue causing timeouts (for example, say 10s timeout). And a second device without network issues which you are gathering data from frequently, say 1s

New Dependency Instructions (If applicable)

[cloudxxx8]

LGTM

[cloudxxx8]

the code change looks good to me, but please modify the commit message and PR title to meet sematic PR check

fix: avoid single conn blocking other device conn

Also, please sign your commit to meet DCO check

[sansmoraxz]

Wouldn't it be better to convert this into RWMutex and use RLock here?