Cause ShutdownPostgres to do a normal transaction abort during backend

exit, instead of trying to take shortcuts.  Introduce some additional
shutdown callback routines to eliminate kluges like having ProcKill
be responsible for shutting down the buffer manager.  Ensure that the
order of operations during shutdown is predictable and what you would
expect given the module layering.

1 files changed, 23 insertions, 3 deletions

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 4fb16eb6145..4633ddef464 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/buffer/bufmgr.c,v 1.190 2005/08/02 20:52:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/buffer/bufmgr.c,v 1.191 2005/08/08 03:11:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,6 +45,7 @@
 #include "storage/buf_internals.h"
 #include "storage/bufmgr.h"
 #include "storage/bufpage.h"
+#include "storage/ipc.h"
 #include "storage/proc.h"
 #include "storage/smgr.h"
 #include "utils/relcache.h"
@@ -93,6 +94,7 @@ static void buffer_write_error_callback(void *arg);
 static BufferDesc *BufferAlloc(Relation reln, BlockNumber blockNum,
 			bool *foundPtr);
 static void FlushBuffer(BufferDesc *buf, SMgrRelation reln);
+static void AtProcExit_Buffers(int code, Datum arg);
 static void write_buffer(Buffer buffer, bool unpin);
 
 
@@ -1080,10 +1082,25 @@ AtEOXact_Buffers(bool isCommit)
 }
 
 /*
- * Ensure we have released all shared-buffer locks and pins during backend exit
+ * InitBufferPoolBackend --- second-stage initialization of a new backend
+ *
+ * This is called after we have acquired a PGPROC and so can safely get
+ * LWLocks.  We don't currently need to do anything at this stage ...
+ * except register a shmem-exit callback.  AtProcExit_Buffers needs LWLock
+ * access, and thereby has to be called at the corresponding phase of
+ * backend shutdown.
  */
 void
-AtProcExit_Buffers(void)
+InitBufferPoolBackend(void)
+{
+	on_shmem_exit(AtProcExit_Buffers, 0);
+}
+
+/*
+ * Ensure we have released all shared-buffer locks and pins during backend exit
+ */
+static void
+AtProcExit_Buffers(int code, Datum arg)
 {
 	int			i;
 
@@ -1105,6 +1122,9 @@ AtProcExit_Buffers(void)
 			Assert(PrivateRefCount[i] == 0);
 		}
 	}
+
+	/* localbuf.c needs a chance too */
+	AtProcExit_LocalBuffers();
 }
 
 /*