Fix inverted write() error check in profile exporter#501
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write() returns -1 on error, not 0. The previous check: - Missed all real errors (ENOSPC, EIO, EPIPE) - False-alarmed on legitimate 0-byte writes Also handle short writes with a loop, since write() may return less than the requested length. Fixes DataDog#498
xroche
marked this pull request as ready for review
February 27, 2026 20:12
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Minor linter fix required |
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closing in favour of #507 |
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What does this PR do?
Fix
write_profile()insrc/exporter/ddprof_exporter.ccwhich checkedwrite() == 0instead ofwrite() < 0.write()returns-1on error, not0. The previous check:The fix also handles short writes with a loop, since
write()may return less than the requested length.Motivation
Profile data was silently lost on disk errors, causing invisible profiling gaps with no diagnostic signal.
How to test the change?
Write to a full filesystem or a closed pipe — the error should now be detected and reported instead of silently ignored.
Classification
Fixes #498