diff options
Diffstat (limited to 'src/backend/storage/ipc/standby.c')
| -rw-r--r-- | src/backend/storage/ipc/standby.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c index 39a30c00f7a..5877a60715f 100644 --- a/src/backend/storage/ipc/standby.c +++ b/src/backend/storage/ipc/standby.c @@ -540,12 +540,34 @@ void ResolveRecoveryConflictWithLock(LOCKTAG locktag, bool logging_conflict) { TimestampTz ltime; + TimestampTz now; Assert(InHotStandby); ltime = GetStandbyLimitTime(); + now = GetCurrentTimestamp(); - if (GetCurrentTimestamp() >= ltime && ltime != 0) + /* + * Update waitStart if first time through after the startup process + * started waiting for the lock. It should not be updated every time + * ResolveRecoveryConflictWithLock() is called during the wait. + * + * Use the current time obtained for comparison with ltime as waitStart + * (i.e., the time when this process started waiting for the lock). Since + * getting the current time newly can cause overhead, we reuse the + * already-obtained time to avoid that overhead. + * + * Note that waitStart is updated without holding the lock table's + * partition lock, to avoid the overhead by additional lock acquisition. + * This can cause "waitstart" in pg_locks to become NULL for a very short + * period of time after the wait started even though "granted" is false. + * This is OK in practice because we can assume that users are likely to + * look at "waitstart" when waiting for the lock for a long time. + */ + if (pg_atomic_read_u64(&MyProc->waitStart) == 0) + pg_atomic_write_u64(&MyProc->waitStart, now); + + if (now >= ltime && ltime != 0) { /* * We're already behind, so clear a path as quickly as possible. |