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-rw-r--r--src/backend/access/transam/xlog.c59
1 files changed, 35 insertions, 24 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 87ea03954bd..3bdd9a2ddd3 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -291,16 +291,15 @@ static bool doPageWrites;
*
* LogwrtRqst indicates a byte position that we need to write and/or fsync
* the log up to (all records before that point must be written or fsynced).
- * LogwrtResult indicates the byte positions we have already written/fsynced.
- * These structs are identical but are declared separately to indicate their
- * slightly different functions.
+ * The positions already written/fsynced are maintained in logWriteResult
+ * and logFlushResult.
*
- * To read XLogCtl->LogwrtResult, you must hold either info_lck or
- * WALWriteLock. To update it, you need to hold both locks. The point of
- * this arrangement is that the value can be examined by code that already
- * holds WALWriteLock without needing to grab info_lck as well. In addition
- * to the shared variable, each backend has a private copy of LogwrtResult,
- * which is updated when convenient.
+ * To read XLogCtl->logWriteResult or ->logFlushResult, you must hold either
+ * info_lck or WALWriteLock. To update them, you need to hold both locks.
+ * The point of this arrangement is that the value can be examined by code
+ * that already holds WALWriteLock without needing to grab info_lck as well.
+ * In addition to the shared variable, each backend has a private copy of
+ * both in LogwrtResult, which is updated when convenient.
*
* The request bookkeeping is simpler: there is a shared XLogCtl->LogwrtRqst
* (protected by info_lck), but we don't need to cache any copies of it.
@@ -478,7 +477,8 @@ typedef struct XLogCtlData
* Protected by info_lck and WALWriteLock (you must hold either lock to
* read it, but both to update)
*/
- XLogwrtResult LogwrtResult;
+ XLogRecPtr logWriteResult; /* last byte + 1 written out */
+ XLogRecPtr logFlushResult; /* last byte + 1 flushed */
/*
* Latest initialized page in the cache (last byte position + 1).
@@ -615,6 +615,15 @@ static int UsableBytesInSegment;
static XLogwrtResult LogwrtResult = {0, 0};
/*
+ * Update local copy of shared XLogCtl->log{Write,Flush}Result
+ */
+#define RefreshXLogWriteResult(_target) \
+ do { \
+ _target.Write = XLogCtl->logWriteResult; \
+ _target.Flush = XLogCtl->logFlushResult; \
+ } while (0)
+
+/*
* openLogFile is -1 or a kernel FD for an open log file segment.
* openLogSegNo identifies the segment, and openLogTLI the corresponding TLI.
* These variables are only used to write the XLOG, and so will normally refer
@@ -960,7 +969,7 @@ XLogInsertRecord(XLogRecData *rdata,
if (XLogCtl->LogwrtRqst.Write < EndPos)
XLogCtl->LogwrtRqst.Write = EndPos;
/* update local result copy while I have the chance */
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
}
@@ -1984,7 +1993,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
SpinLockAcquire(&XLogCtl->info_lck);
if (XLogCtl->LogwrtRqst.Write < OldPageRqstPtr)
XLogCtl->LogwrtRqst.Write = OldPageRqstPtr;
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
/*
@@ -2005,7 +2014,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
if (LogwrtResult.Write >= OldPageRqstPtr)
{
/* OK, someone wrote it already */
@@ -2289,7 +2298,7 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
/*
* Update local LogwrtResult (caller probably did this already, but...)
*/
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
/*
* Since successive pages in the xlog cache are consecutively allocated,
@@ -2549,7 +2558,8 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
*/
{
SpinLockAcquire(&XLogCtl->info_lck);
- XLogCtl->LogwrtResult = LogwrtResult;
+ XLogCtl->logWriteResult = LogwrtResult.Write;
+ XLogCtl->logFlushResult = LogwrtResult.Flush;
if (XLogCtl->LogwrtRqst.Write < LogwrtResult.Write)
XLogCtl->LogwrtRqst.Write = LogwrtResult.Write;
if (XLogCtl->LogwrtRqst.Flush < LogwrtResult.Flush)
@@ -2572,7 +2582,7 @@ XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN)
XLogRecPtr prevAsyncXactLSN;
SpinLockAcquire(&XLogCtl->info_lck);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
sleeping = XLogCtl->WalWriterSleeping;
prevAsyncXactLSN = XLogCtl->asyncXactLSN;
if (XLogCtl->asyncXactLSN < asyncXactLSN)
@@ -2784,7 +2794,7 @@ XLogFlush(XLogRecPtr record)
SpinLockAcquire(&XLogCtl->info_lck);
if (WriteRqstPtr < XLogCtl->LogwrtRqst.Write)
WriteRqstPtr = XLogCtl->LogwrtRqst.Write;
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
/* done already? */
@@ -2815,7 +2825,7 @@ XLogFlush(XLogRecPtr record)
}
/* Got the lock; recheck whether request is satisfied */
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
if (record <= LogwrtResult.Flush)
{
LWLockRelease(WALWriteLock);
@@ -2939,7 +2949,7 @@ XLogBackgroundFlush(void)
/* read LogwrtResult and update local state */
SpinLockAcquire(&XLogCtl->info_lck);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
WriteRqst = XLogCtl->LogwrtRqst;
SpinLockRelease(&XLogCtl->info_lck);
@@ -3027,7 +3037,7 @@ XLogBackgroundFlush(void)
/* now wait for any in-progress insertions to finish and get write lock */
WaitXLogInsertionsToFinish(WriteRqst.Write);
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
if (WriteRqst.Write > LogwrtResult.Write ||
WriteRqst.Flush > LogwrtResult.Flush)
{
@@ -3116,7 +3126,7 @@ XLogNeedsFlush(XLogRecPtr record)
/* read LogwrtResult and update local state */
SpinLockAcquire(&XLogCtl->info_lck);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
/* check again */
@@ -5953,7 +5963,8 @@ StartupXLOG(void)
LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
- XLogCtl->LogwrtResult = LogwrtResult;
+ XLogCtl->logWriteResult = LogwrtResult.Write;
+ XLogCtl->logFlushResult = LogwrtResult.Flush;
XLogCtl->LogwrtRqst.Write = EndOfLog;
XLogCtl->LogwrtRqst.Flush = EndOfLog;
@@ -6400,7 +6411,7 @@ GetFlushRecPtr(TimeLineID *insertTLI)
Assert(XLogCtl->SharedRecoveryState == RECOVERY_STATE_DONE);
SpinLockAcquire(&XLogCtl->info_lck);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
/*
@@ -9316,7 +9327,7 @@ XLogRecPtr
GetXLogWriteRecPtr(void)
{
SpinLockAcquire(&XLogCtl->info_lck);
- LogwrtResult = XLogCtl->LogwrtResult;
+ RefreshXLogWriteResult(LogwrtResult);
SpinLockRelease(&XLogCtl->info_lck);
return LogwrtResult.Write;
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-30 12:05:12 +0000