Protect access to the taskid to deal with different threads. #403
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The requests can be made on one thread, but the expire on another thread. tsan flagged this potential race, so add the needed guards so the access is as safe as possible given the system api's required usage.
mwyman
reviewed
Oct 6, 2020
| @synchronized(self) { | ||
| if (bgTaskID == self.backgroundTaskIdentifier) { | ||
| if (localTaskID == self.backgroundTaskIdentifier) { |
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Is there utility to this check anymore, given that guardedTaskID is set inside the @synchronized(self) block below and read in an @synchronized(self) block above?
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Yes, if there is a race with starting a retry, then we'll already be on to the new taskid, so when the first one's expire fires, we don't want to break the connection to the new one, just clean up the old one by ending it.
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The requests can be made on one thread, but the expire on another thread.
tsan flagged this potential race, so add the needed guards so the access
is as safe as possible given the system api's required usage.