Significant cleanups in SysV IPC handling (shared mem and semaphores).

IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c.  TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.

1 files changed, 8 insertions, 24 deletions

diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index bee4f7e9219..0454ffc8486 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.72 2000/11/16 22:30:39 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.73 2000/11/28 23:27:57 tgl Exp $
  *
  *
  *-------------------------------------------------------------------------
@@ -45,7 +45,6 @@
 static void ReverifyMyDatabase(const char *name);
 static void InitCommunication(void);
 
-static IPCKey PostgresIpcKey;
 
 /*** InitPostgres support ***/
 
@@ -141,7 +140,7 @@ ReverifyMyDatabase(const char *name)
  * --------------------------------
  */
 static void
-InitCommunication()
+InitCommunication(void)
 {
 	/* ----------------
 	 *	initialize shared memory and semaphores appropriately.
@@ -151,26 +150,11 @@ InitCommunication()
 	{
 		/* ----------------
 		 *	we're running a postgres backend by itself with
-		 *	no front end or postmaster.
+		 *	no front end or postmaster.  Create private "shmem"
+		 *	and semaphores.  Setting MaxBackends = 16 is arbitrary.
 		 * ----------------
 		 */
-		char	   *ipc_key;	/* value of environment variable */
-		IPCKey		key;
-
-		ipc_key = getenv("IPC_KEY");
-
-		if (!PointerIsValid(ipc_key))
-		{
-			/* Normal standalone backend */
-			key = PrivateIPCKey;
-		}
-		else
-		{
-			/* Allow standalone's IPC key to be set */
-			key = atoi(ipc_key);
-		}
-		PostgresIpcKey = key;
-		AttachSharedMemoryAndSemaphores(key);
+		CreateSharedMemoryAndSemaphores(true, 16);
 	}
 }
 
@@ -295,7 +279,7 @@ InitPostgres(const char *dbname, const char *username)
 	/*
 	 * Set up my per-backend PROC struct in shared memory.
 	 */
-	InitProcess(PostgresIpcKey);
+	InitProcess();
 
 	/*
 	 * Initialize my entry in the shared-invalidation manager's array of
@@ -307,7 +291,7 @@ InitPostgres(const char *dbname, const char *username)
 	 */
 	MyBackendId = InvalidBackendId;
 
-	InitSharedInvalidationState();
+	InitBackendSharedInvalidationState();
 
 	if (MyBackendId > MAXBACKENDS || MyBackendId <= 0)
 		elog(FATAL, "cinit2: bad backend id %d", MyBackendId);
@@ -365,11 +349,11 @@ BaseInit(void)
 	 */
 	InitCommunication();
 	DebugFileOpen();
+
 	smgrinit();
 
 	EnablePortalManager();		/* memory for portal/transaction stuff */
 
 	/* initialize the local buffer manager */
 	InitLocalBuffer();
-
 }