Fix race when stopping chunks memcached client #4511
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We need to check again if we have been asked to quit before writing to the results chan. Also, the reader of that chan should not close it, because this can trigger a panic in a writer. The chan will be cleaned up by garbage- collection once all the readers and writers have exited on quit. Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
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rsteneteg
reviewed
Oct 1, 2021
pkg/chunk/cache/memcached.go
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| case <-c.quit: | ||
| return | ||
| default: | ||
| input.resultCh <- res |
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sending on the channel inside the default case seems that it could still block if it enters the default clause just before quit is closed.
Can we make it a case instead?
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Sorry was on vacation. Very good point; done.
Don't open another race where quit is closed just after we check it. Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
|
LGTM |
alvinlin123
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Oct 14, 2021
srijan55
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Nov 26, 2021
* Fix race when stopping chunks memcached client We need to check again if we have been asked to quit before writing to the results chan. Also, the reader of that chan should not close it, because this can trigger a panic in a writer. The chan will be cleaned up by garbage- collection once all the readers and writers have exited on quit. Signed-off-by: Bryan Boreham <bjboreham@gmail.com> * simplify select Don't open another race where quit is closed just after we check it. Signed-off-by: Bryan Boreham <bjboreham@gmail.com> Signed-off-by: Manish Kumar Gupta <manishkg@microsoft.com>
alvinlin123
pushed a commit
to ac1214/cortex
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Jan 14, 2022
* Fix race when stopping chunks memcached client We need to check again if we have been asked to quit before writing to the results chan. Also, the reader of that chan should not close it, because this can trigger a panic in a writer. The chan will be cleaned up by garbage- collection once all the readers and writers have exited on quit. Signed-off-by: Bryan Boreham <bjboreham@gmail.com> * simplify select Don't open another race where quit is closed just after we check it. Signed-off-by: Bryan Boreham <bjboreham@gmail.com> Signed-off-by: Alvin Lin <alvinlin@amazon.com>
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We need to check again if we have been asked to quit before writing to the results chan.
Also, the reader of that chan should not close it, because this can trigger a panic in a writer. The chan will be cleaned up by garbage-collection once all the readers and writers have exited on quit.
Which issue(s) this PR fixes:
Fixes #4508
Checklist
CHANGELOG.mdupdated