Repository navigation
Pass the tar error over a channel in 'mtree' - #425
Merged
Merged
Conversation
Walking a directory runs Tar in a goroutine writing into a pipe while UnTar reads it. UnTar can stop before the stream ends, a cancelled context being one way, and the main goroutine then read tarErr while the Tar goroutine was still assigning it. Send the error over a channel instead, and close the read end of the pipe first so Tar isn't left blocked writing into it and can be waited for. The command writes to the package's stdout writer, which is what lets it be tested at all; these are its first tests.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Walking a directory runs
Tarin a goroutine writing into a pipe whileUnTarreads it.UnTarcan stop before the stream ends — a cancelled context being one way — and the main goroutine then readtarErrwhile theTargoroutine was still assigning it. The equivalent intar.gois safe only becauseChunkStreamcannot return nil before the pipe writer closes.The error now goes over a channel, and the read end of the pipe is closed first so
Taris not left blocked writing into a pipe nobody reads, which is what makes waiting for it safe.mtreehad no tests, so this adds them for all three input kinds. The cancelled-context case reproduces the race:go test -racereportsDATA RACEon it before the change and passes twenty consecutive runs after. CI already runs the race detector over the package.The command writes to the package's
stdoutwriter rather thanos.Stdoutdirectly, which is what lets the output be checked at all.