[tor-bugs] #21312 [Obfuscation/Snowflake]: snowflake-client is pegged at 100% cpu

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#21312: snowflake-client is pegged at 100% cpu
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 Reporter:  arlolra                |          Owner:  arlolra
     Type:  defect                 |         Status:  needs_review
 Priority:  High                   |      Milestone:
Component:  Obfuscation/Snowflake  |        Version:
 Severity:  Major                  |     Resolution:
 Keywords:                         |  Actual Points:
Parent ID:                         |         Points:
 Reviewer:                         |        Sponsor:
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Comment (by dcf):

 Replying to [comment:54 arlolra]:
 > I've added two updated patches which I guess are now the things to
 review and test here.  They supersede anything I posted above that isn't
 already merged.

 Thank you so much.

 I've started some proxy-go instances with the patches. The one on my
 desktop has seen a few opens and closes so far, and is still running. I'll
 make more graphs of restarts tomorrow, but so far it's looking good, one
 hour without any abnormal restarts.

 attachment:0001-Add-synchronization-to-manipulating-vectors.patch looks
 ok.

 About attachment:0001-Add-synchronization-around-destroying-
 dataChannels-a.patch:
  * `WebRTCPeer` uses the names `lock` and `once`, but `webRTCConn` uses
 the names `lk` and `do`. Is there a reason for the difference. I think I
 prefer the `lock` and `once` names.
  * I tried to work out what exact members the synchonization covers. I
 think it is:
    * `WebRTCPeer.lock` covers `transport` (a DataChannel).
    * `WebRTCPeer.once` covers `pc` (only destroying / setting to `nil`).
    * `webRTCConn.lk` covers `dc` (a DataChannel).
    * `webRTCConn.do` covers `pc` (only destroying).
   Do I have it right? I would like there to be comments by each of the
 declarations, stating what their responsibilities are.
  * Small typo: "since we'll otherwise we'll end up".

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21312#comment:55>
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