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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2025-11-18 09:50:12 +0200 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2025-11-18 09:50:12 +0200 |
| commit | 75e82b2f5a6f5de6b42dbd9ea73be5ff36a931b1 (patch) | |
| tree | 5afe5c07b0e2872574b8ae0bf30b63ce989ab409 /src/include/access/xlogwait.h | |
| parent | 694b4ab33b24dfe1f9cc00fbbd5326f0feadee4a (diff) | |
Optimize shared memory usage for WaitLSNProcInfo
We need separate pairing heaps for different WaitLSNType's, because there
might be waiters for different LSN's at the same time. However, one process
can wait only for one type of LSN at a time. So, no need for inHeap
and heapNode fields to be arrays.
Discussion: https://postgr.es/m/CAPpHfdsBR-7sDtXFJ1qpJtKiohfGoj%3DvqzKVjWxtWsWidx7G_A%40mail.gmail.com
Author: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Diffstat (limited to 'src/include/access/xlogwait.h')
| -rw-r--r-- | src/include/access/xlogwait.h | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/include/access/xlogwait.h b/src/include/access/xlogwait.h index f43e481c3b9..e607441d618 100644 --- a/src/include/access/xlogwait.h +++ b/src/include/access/xlogwait.h @@ -50,14 +50,20 @@ typedef struct WaitLSNProcInfo /* LSN, which this process is waiting for */ XLogRecPtr waitLSN; + /* The type of LSN to wait */ + WaitLSNType lsnType; + /* Process to wake up once the waitLSN is reached */ ProcNumber procno; - /* Heap membership flags for LSN types */ - bool inHeap[WAIT_LSN_TYPE_COUNT]; + /* + * Heap membership flag. A process can wait for only one LSN type at a + * time, so a single flag suffices (tracked by the lsnType field). + */ + bool inHeap; - /* Heap nodes for LSN types */ - pairingheap_node heapNode[WAIT_LSN_TYPE_COUNT]; + /* Pairing heap node for the waiters' heap (one per process) */ + pairingheap_node heapNode; } WaitLSNProcInfo; /* |