[AsyncFileHandler] insure good synchronization for 'fRecordBuffer' #70
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PatrickTasse
requested changes
Jun 4, 2025
| private volatile boolean fIsEnabled = true; | ||
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| private List<LogRecord> fRecordBuffer = new ArrayList<>(fMaxSize); | ||
| private volatile List<LogRecord> fRecordBuffer = new ArrayList<>(fMaxSize); |
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The record buffer is already used with synchronization, except the empty check in the timer thread. This check could be moved to the flush() method and then all read and write accesses would always be synchronized.
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I agree - I will update the PR
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This field is accessed by various threads, whenever logging is happening. All accesses are synchronized except the empty check in timer thread, done before calling flush(). Once in a while, the record buffer is flushed to the writer queue and a new, empty buffer is created and assigned to "fRecordBuffer". If that happens just before the timer task does its empty check, that thread might still see the old buffer, and then the call to flush() might result in adding an empty buffer to the queue. To avoid that, the empty check has been moved inside the synchronized flush() function. Also, for explicitness sake, mark field fFileHandler as final. It's already used as such, and is only set in the constructor, but this makes it explicit. Signed-off-by: Marc Dumais <[email protected]>
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PatrickTasse
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bhufmann
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What it does
This field is accessed by various threads, whenever logging is happening. All accesses are synchronized except the empty check in timer thread, done before calling flush().
Once in a while, the record buffer is flushed to the writer queue and a new, empty buffer is created and assigned to "fRecordBuffer". If that happens just before the timer task does its empty check, that thread might still see the old buffer, and then the call to flush() might result in adding an empty buffer to the queue. To avoid that, the empty check has been moved inside the synchronized flush() function.
Also, for explicitness's sake, mark field fFileHandler as final. It's already used as such, and is only set in the constructor, but this makes it explicit.
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