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Fix race condition in cmdio.LogString - #3868
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Make LogString write the string and newline in a single call to reduce the likelihood of interleaved output when called concurrently. Note: This fix assumes io.WriteString provides atomic writes for small messages, which is not guaranteed by the Go specification. Fixes flaky test from: https://github.com/databricks/cli/actions/runs/18995883239/job/54255615389
pietern
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| c := fromContext(ctx) | ||
| _, _ = io.WriteString(c.err, str) | ||
| _, _ = io.WriteString(c.err, "\n") | ||
| _, _ = io.WriteString(c.err, str+"\n") |
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Note: This fix assumes io.WriteString provides atomic writes for small messages, which is not guaranteed.
if it's not guaranteed should we add the lock back?
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There are other call sites where we write to the same output.
It deserves a better fix but that's more work than trying this out.
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18 failing tests:
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denik pushed a commit
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## Changes Make `LogString` write the string and newline in a single call to reduce the likelihood of interleaved output when called concurrently. This was atomic until #3818 where I removed the lock, assuming it wasn't necessary. Note: This fix assumes `io.WriteString` provides atomic writes for small messages, which is not guaranteed. ## Why Fixes flaky test from: https://github.com/databricks/cli/actions/runs/18995883239/job/54255615389
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Changes
Make
LogStringwrite the string and newline in a single call to reduce the likelihood of interleaved output when called concurrently. This was atomic until #3818 where I removed the lock, assuming it wasn't necessary.Note: This fix assumes
io.WriteStringprovides atomic writes for small messages, which is not guaranteed.Why
Fixes flaky test from: https://github.com/databricks/cli/actions/runs/18995883239/job/54255615389