1 files changed, 10 insertions, 87 deletions

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 3b2eb95d4fc..9fa4ebb3689 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.193 2000/11/27 04:03:20 inoue Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.194 2000/11/28 23:27:55 tgl Exp $
  *
  * NOTES
  *
@@ -118,26 +118,6 @@ char * UnixSocketDir;
 char * Virtual_host;
 
 /*
- * This is a sequence number that indicates how many times we've had to
- * throw away the shared memory and start over because we doubted its
- * integrity.	It starts off at zero and is incremented every time we
- * start over.  We use this to ensure that we use a new IPC shared memory
- * key for the new shared memory segment in case the old segment isn't
- * entirely gone yet.
- *
- * The sequence actually cycles back to 0 after 9, so pathologically there
- * could be an IPC failure if 10 sets of backends are all stuck and won't
- * release IPC resources.
- */
-static short shmem_seq = 0;
-
-/*
- * This is the base IPC shared memory key.  Other keys are generated by
- * adding to this.
- */
-static IpcMemoryKey ipc_key;
-
-/*
  * MaxBackends is the actual limit on the number of backends we will
  * start. The default is established by configure, but it can be
  * readjusted from 1..MAXBACKENDS with the postmaster -N switch. Note
@@ -1292,39 +1272,6 @@ ConnFree(Port *conn)
 	free(conn);
 }
 
-/*
- * get_host_port -- return a pseudo port number (16 bits)
- * derived from the primary IP address of Virtual_host.
- */
-static unsigned short
-get_host_port(void)
-{
-	static unsigned short hostPort = 0;
-
-	if (hostPort == 0)
-	{
-		SockAddr	saddr;
-		struct hostent *hp;
-
-		hp = gethostbyname(Virtual_host);
-		if ((hp == NULL) || (hp->h_addrtype != AF_INET))
-		{
-			char msg[1024];
-			snprintf(msg, sizeof(msg),
-				 "FATAL: get_host_port: gethostbyname(%s) failed\n",
-				 Virtual_host);
-			fputs(msg, stderr);
-			pqdebug("%s", msg);
-			exit(1);
-		}
-		memmove((char *) &(saddr.in.sin_addr),
-			(char *) hp->h_addr,
-			hp->h_length);
-		hostPort = ntohl(saddr.in.sin_addr.s_addr) & 0xFFFF;
-	}
-
-	return hostPort;
-}
 
 /*
  * reset_shared -- reset shared memory and semaphores
@@ -1333,40 +1280,16 @@ static void
 reset_shared(unsigned short port)
 {
 	/*
-	 * A typical ipc_key is 5432001, which is port 5432, sequence
-	 * number 0, and 01 as the index in IPCKeyGetBufferMemoryKey().
-	 * The 32-bit INT_MAX is 2147483 6 47.
-	 *
-	 * The default algorithm for calculating the IPC keys assumes that all
-	 * instances of postmaster on a given host are listening on different
-	 * ports.  In order to work (prevent shared memory collisions) if you
-	 * run multiple PostgreSQL instances on the same port and different IP
-	 * addresses on a host, we change the algorithm if you give postmaster
-	 * the -h option, or set PGHOST, to a value other than the internal
-	 * default.
-	 *
-	 * If Virtual_host is set, then we generate the IPC keys using the
-	 * last two octets of the IP address instead of the port number.
-	 * This algorithm assumes that no one will run multiple PostgreSQL
-	 * instances on one host using two IP addresses that have the same two
-	 * last octets in different class C networks.  If anyone does, it
-	 * would be rare.
-	 *
-	 * So, if you use -h or PGHOST, don't try to run two instances of
-	 * PostgreSQL on the same IP address but different ports.  If you
-	 * don't use them, then you must use different ports (via -p or
-	 * PGPORT).  And, of course, don't try to use both approaches on one
-	 * host.
+	 * Reset assignment of shared mem and semaphore IPC keys.
+	 * Doing this means that in normal cases we'll assign the same keys
+	 * on each "cycle of life", and thereby avoid leaving dead IPC objects
+	 * floating around if the postmaster crashes and is restarted.
 	 */
-
-	if (Virtual_host[0] != '\0')
-		port = get_host_port();
-
-	ipc_key = port * 1000 + shmem_seq * 100;
-	CreateSharedMemoryAndSemaphores(ipc_key, MaxBackends);
-	shmem_seq += 1;
-	if (shmem_seq >= 10)
-		shmem_seq -= 10;
+	IpcInitKeyAssignment(port);
+	/*
+	 * Create or re-create shared memory and semaphores.
+	 */
+	CreateSharedMemoryAndSemaphores(false, MaxBackends);
 }