diff options
| -rw-r--r-- | src/backend/access/transam/xlog.c | 25 | ||||
| -rw-r--r-- | src/backend/storage/ipc/sinvaladt.c | 41 | ||||
| -rw-r--r-- | src/include/storage/sinvaladt.h | 1 |
3 files changed, 67 insertions, 0 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 7654ad76de1..f1a795bba9f 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -70,6 +70,7 @@ #include "storage/proc.h" #include "storage/procarray.h" #include "storage/reinit.h" +#include "storage/sinvaladt.h" #include "storage/smgr.h" #include "storage/spin.h" #include "storage/sync.h" @@ -8020,6 +8021,30 @@ StartupXLOG(void) } /* + * Invalidate all sinval-managed caches before READ WRITE transactions + * begin. The xl_heap_inplace WAL record doesn't store sufficient data + * for invalidations. The commit record, if any, has the invalidations. + * However, the inplace update is permanent, whether or not we reach a + * commit record. Fortunately, read-only transactions tolerate caches not + * reflecting the latest inplace updates. Read-only transactions + * experience the notable inplace updates as follows: + * + * - relhasindex=true affects readers only after the CREATE INDEX + * transaction commit makes an index fully available to them. + * + * - datconnlimit=DATCONNLIMIT_INVALID_DB affects readers only at + * InitPostgres() time, and that read does not use a cache. + * + * - relfrozenxid, datfrozenxid, relminmxid, and datminmxid have no effect + * on readers. + * + * Hence, hot standby queries (all READ ONLY) function correctly without + * the missing invalidations. This avoided changing the WAL format in + * back branches. + */ + SIResetAll(); + + /* * Preallocate additional log files, if wanted. */ PreallocXlogFiles(EndOfLog); diff --git a/src/backend/storage/ipc/sinvaladt.c b/src/backend/storage/ipc/sinvaladt.c index 946bd8e3cb5..f0e2fb96ea3 100644 --- a/src/backend/storage/ipc/sinvaladt.c +++ b/src/backend/storage/ipc/sinvaladt.c @@ -748,6 +748,47 @@ SICleanupQueue(bool callerHasWriteLock, int minFree) } } +/* + * SIResetAll + * Mark all active backends as "reset" + * + * Use this when we don't know what needs to be invalidated. It's a + * cluster-wide InvalidateSystemCaches(). This was a back-branch-only remedy + * to avoid a WAL format change. + * + * The implementation is like SICleanupQueue(false, MAXNUMMESSAGES + 1), with + * one addition. SICleanupQueue() assumes minFree << MAXNUMMESSAGES, so it + * assumes hasMessages==true for any backend it resets. We're resetting even + * fully-caught-up backends, so we set hasMessages. + */ +void +SIResetAll(void) +{ + SISeg *segP = shmInvalBuffer; + int i; + + LWLockAcquire(SInvalWriteLock, LW_EXCLUSIVE); + LWLockAcquire(SInvalReadLock, LW_EXCLUSIVE); + + for (i = 0; i < segP->lastBackend; i++) + { + ProcState *stateP = &segP->procState[i]; + + if (stateP->procPid == 0 || stateP->sendOnly) + continue; + + /* Consuming the reset will update "nextMsgNum" and "signaled". */ + stateP->resetState = true; + stateP->hasMessages = true; + } + + segP->minMsgNum = segP->maxMsgNum; + segP->nextThreshold = CLEANUP_MIN; + + LWLockRelease(SInvalReadLock); + LWLockRelease(SInvalWriteLock); +} + /* * GetNextLocalTransactionId --- allocate a new LocalTransactionId diff --git a/src/include/storage/sinvaladt.h b/src/include/storage/sinvaladt.h index 14148bf8201..07d229a5cb2 100644 --- a/src/include/storage/sinvaladt.h +++ b/src/include/storage/sinvaladt.h @@ -37,6 +37,7 @@ extern void BackendIdGetTransactionIds(int backendID, TransactionId *xid, Transa extern void SIInsertDataEntries(const SharedInvalidationMessage *data, int n); extern int SIGetDataEntries(SharedInvalidationMessage *data, int datasize); extern void SICleanupQueue(bool callerHasWriteLock, int minFree); +extern void SIResetAll(void); extern LocalTransactionId GetNextLocalTransactionId(void); |