+ * This .ready file is created out of order, notify archiver to perform + * a full directory scan to archive corresponding WAL file. + */ + StatusFilePath(archiveStatusPath, xlog, ".ready"); + if (stat(archiveStatusPath, &stat_buf) == 0) + PgArchEnableDirScan();
We may want to call PgArchWakeup() after setting the flag. + * Perform a full directory scan to identify the next log segment. There + * may be one of the following scenarios which may require us to perform a + * full directory scan. ... + * - The next anticipated log segment is not available. I wonder if we really need to perform a directory scan in this case. Unless there are other cases where the .ready files are created out of order, I think this just causes an unnecessary directory scan every time the archiver catches up. + * Flag to enable/disable directory scan. If this flag is set then it + * forces archiver to perform a full directory scan to get the next log + * segment. + */ + pg_atomic_flag dirScan; I personally don't think it's necessary to use an atomic here. A spinlock or LWLock would probably work just fine, as contention seems unlikely. If we use a lock, we also don't have to worry about memory barriers. Nathan
