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mirror of https://github.com/postgres/postgres.git synced 2025-06-26 12:21:12 +03:00

Change ProcSendSignal() to take pgprocno.

Instead of referring to target backends by pid, use pgprocno.  This
means that we don't have to scan the ProcArray and we can drop some
special case code for dealing with the startup process.

Discussion: https://postgr.es/m/CA%2BhUKGLYRyDaneEwz5Uya_OgFLMx5BgJfkQSD%3Dq9HmwsfRRb-w%40mail.gmail.com
Reviewed-by: Soumyadeep Chakraborty <soumyadeep2007@gmail.com>
Reviewed-by: Ashwin Agrawal <ashwinstar@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
This commit is contained in:
Thomas Munro
2021-12-16 12:40:15 +13:00
parent bbc227e951
commit a13db0e164
8 changed files with 23 additions and 64 deletions

View File

@ -1899,11 +1899,11 @@ UnpinBuffer(BufferDesc *buf, bool fixOwner)
BUF_STATE_GET_REFCOUNT(buf_state) == 1)
{
/* we just released the last pin other than the waiter's */
int wait_backend_pid = buf->wait_backend_pid;
int wait_backend_pgprocno = buf->wait_backend_pgprocno;
buf_state &= ~BM_PIN_COUNT_WAITER;
UnlockBufHdr(buf, buf_state);
ProcSendSignal(wait_backend_pid);
ProcSendSignal(wait_backend_pgprocno);
}
else
UnlockBufHdr(buf, buf_state);
@ -3980,7 +3980,7 @@ UnlockBuffers(void)
* got a cancel/die interrupt before getting the signal.
*/
if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
buf->wait_backend_pid == MyProcPid)
buf->wait_backend_pgprocno == MyProc->pgprocno)
buf_state &= ~BM_PIN_COUNT_WAITER;
UnlockBufHdr(buf, buf_state);
@ -4116,7 +4116,7 @@ LockBufferForCleanup(Buffer buffer)
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
elog(ERROR, "multiple backends attempting to wait for pincount 1");
}
bufHdr->wait_backend_pid = MyProcPid;
bufHdr->wait_backend_pgprocno = MyProc->pgprocno;
PinCountWaitBuf = bufHdr;
buf_state |= BM_PIN_COUNT_WAITER;
UnlockBufHdr(bufHdr, buf_state);
@ -4187,7 +4187,7 @@ LockBufferForCleanup(Buffer buffer)
*/
buf_state = LockBufHdr(bufHdr);
if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
bufHdr->wait_backend_pid == MyProcPid)
bufHdr->wait_backend_pgprocno == MyProc->pgprocno)
buf_state &= ~BM_PIN_COUNT_WAITER;
UnlockBufHdr(bufHdr, buf_state);