Feature/add lock anno

[LXPWing]

What this PR does:
#112
add comments to lock related code

[mosn-community-bot]

Hi @LXPWing, welcome to mosn community, Please sign Contributor License Agreement!

After you signed CLA, we will automatically sync the status of this pull request in 3 minutes.

[seeflood]

Thanks for your contribution!
Please sign the cla so that we can merge this pr

[LXPWing]

I have signed the CLA, but it shows here that I have not signed the CLA,What can I do to fix it?

[seeflood]

Sorry for the inconvenience :(
Now the bot seems back to normal

[codecov]

Codecov Report

Merging #290 (5ccf3e2) into main (b3a9740) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #290   +/-   ##
=======================================
  Coverage   56.73%   56.73%           
=======================================
  Files          48       48           
  Lines        2057     2057           
=======================================
  Hits         1167     1167           
  Misses        768      768           
  Partials      122      122           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b3a9740...5ccf3e2. Read the comment docs.

[seeflood]

LGTM

[seeflood]

Thanks again for your help,and welcome to the Layotto community!