On 2020/12/17 11:04, Fujii Masao wrote:
Hi,
When the startup process needs to wait for recovery conflict on lock,
STANDBY_LOCK_TIMEOUT is enabled to interrupt ProcWaitForSignal()
if necessary. If this timeout happens, StandbyLockTimeoutHandler() is
called and this function does nothing as follows.
/*
* StandbyLockTimeoutHandler() will be called if STANDBY_LOCK_TIMEOUT is
exceeded.
* This doesn't need to do anything, simply waking up is enough.
*/
void
StandbyLockTimeoutHandler(void)
{
}
But if STANDBY_LOCK_TIMEOUT happens just before entering ProcWaitForSignal(),
the timeout fails to interrupt that wait. Also a signal sent by this timeout
doesn't interrupt poll() used in ProcWaitForSignal(), on all platforms.
So I think that StandbyLockTimeoutHandler() should do SetLatch(MyLatch)
so that the timeout can interrupt ProcWaitForSignal() even in those cases.
Thought?
Patch attached.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
diff --git a/src/backend/storage/ipc/standby.c
b/src/backend/storage/ipc/standby.c
index 92d9027776..b690c86637 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -620,11 +620,15 @@ StandbyTimeoutHandler(void)
/*
* StandbyLockTimeoutHandler() will be called if STANDBY_LOCK_TIMEOUT is
exceeded.
- * This doesn't need to do anything, simply waking up is enough.
+ * This doesn't set flag, simply waking up is enough.
*/
void
StandbyLockTimeoutHandler(void)
{
+ int save_errno = errno;
+
+ SetLatch(MyLatch);
+ errno = save_errno;
}
/*
