From 897a895d323799ca66db1b20a04e6d34ddc07045 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 8 Feb 2001 00:35:10 +0000
Subject: [PATCH] When launching a child backend, take care to close file
 descriptors for any other client connections that may exist (which would only
 happen if another client is currently in the authentication cycle).  This
 avoids wastage of open descriptors in a child.  It might also explain
 peculiar behaviors like not closing connections when expected, since the
 kernel will probably not signal EOF as long as some other backend is randomly
 holding open a reference to the connection, even if the client went away long
 since ...

---
 src/backend/postmaster/postmaster.c | 70 ++++++++++++++++++++++-------
 1 file changed, 53 insertions(+), 17 deletions(-)

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 98fff8b6af..763f482608 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 1.204 2001/01/27 00:05:31 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.205 2001/02/08 00:35:10 tgl Exp $
  *
  * NOTES
  *
@@ -202,6 +202,7 @@ extern void GetRedoRecPtr(void);
 static void pmdaemonize(int argc, char *argv[]);
 static Port *ConnCreate(int serverFd);
 static void ConnFree(Port *port);
+static void ClosePostmasterPorts(Port *myConn);
 static void reset_shared(unsigned short port);
 static void SIGHUP_handler(SIGNAL_ARGS);
 static void pmdie(SIGNAL_ARGS);
@@ -1285,6 +1286,51 @@ ConnFree(Port *conn)
 	free(conn);
 }
 
+/*
+ * ClosePostmasterPorts -- close all the postmaster's open sockets
+ *
+ * This is called during child process startup to release file descriptors
+ * that are not needed by that child process.  All descriptors other than
+ * the one for myConn (if it's not null) are closed.
+ *
+ * Note that closing the child's descriptor does not destroy the client
+ * connection prematurely, since the parent (postmaster) process still
+ * has the socket open.
+ */
+static void
+ClosePostmasterPorts(Port *myConn)
+{
+	Dlelem	   *curr;
+
+	/* Close the listen sockets */
+	if (NetServer)
+		StreamClose(ServerSock_INET);
+	ServerSock_INET = INVALID_SOCK;
+#ifdef HAVE_UNIX_SOCKETS
+	StreamClose(ServerSock_UNIX);
+	ServerSock_UNIX = INVALID_SOCK;
+#endif
+
+	/* Close any sockets for other clients, and release memory too */
+	curr = DLGetHead(PortList);
+
+	while (curr)
+	{
+		Port	   *port = (Port *) DLE_VAL(curr);
+		Dlelem	   *next = DLGetSucc(curr);
+
+		if (port != myConn)
+		{
+			StreamClose(port->sock);
+			DLRemove(curr);
+			ConnFree(port);
+			DLFreeElem(curr);
+		}
+
+		curr = next;
+	}
+}
+
 
 /*
  * reset_shared -- reset shared memory and semaphores
@@ -1918,21 +1964,15 @@ DoBackend(Port *port)
 	 * Signal handlers setting is moved to tcop/postgres...
 	 */
 
-	/* Close the postmaster sockets */
-	if (NetServer)
-		StreamClose(ServerSock_INET);
-	ServerSock_INET = INVALID_SOCK;
-#ifdef HAVE_UNIX_SOCKETS
-	StreamClose(ServerSock_UNIX);
-	ServerSock_UNIX = INVALID_SOCK;
-#endif
-
 	/* Save port etc. for ps status */
 	MyProcPort = port;
 
 	/* Reset MyProcPid to new backend's pid */
 	MyProcPid = getpid();
 
+	/* Close the postmaster's other sockets */
+	ClosePostmasterPorts(port);
+
 	/*
 	 * Don't want backend to be able to see the postmaster random number
 	 * generator state.  We have to clobber the static random_seed *and*
@@ -2225,13 +2265,9 @@ SSDataBase(int xlop)
 		/* Lose the postmaster's on-exit routines and port connections */
 		on_exit_reset();
 
-		if (NetServer)
-			StreamClose(ServerSock_INET);
-		ServerSock_INET = INVALID_SOCK;
-#ifdef HAVE_UNIX_SOCKETS
-		StreamClose(ServerSock_UNIX);
-		ServerSock_UNIX = INVALID_SOCK;
-#endif
+		/* Close the postmaster's sockets */
+		ClosePostmasterPorts(NULL);
+
 
 		av[ac++] = "postgres";
 
-- 
2.40.0