Add switching to next host:port to DTMD.

Author: kvap

contrib/pg_dtm/libdtm.c

@@ -113,12 +113,9 @@ static bool DtmConnect(DTMConn conn)
 
 	if (conn->host == NULL)
 	{
-		perror("unix socket not supported yet");
-		*(int*)0 = 0;
-		/*
 		// use a UNIX socket
 		struct sockaddr sock;
-		int len = offsetof(struct sockaddr, sa_data) + snprintf(sock.sa_data, sizeof(sock.sa_data), "%s/p%u", dtm_unix_sock_dir, port);
+		int len = offsetof(struct sockaddr, sa_data) + snprintf(sock.sa_data, sizeof(sock.sa_data), "%s/sh.unix", dtm_unix_sock_dir);
 		sock.sa_family = AF_UNIX;
 
 		sd = socket(AF_UNIX, SOCK_STREAM, 0);
@@ -137,7 +134,6 @@ static bool DtmConnect(DTMConn conn)
 		}
 		conn->sock = sd;
 		return (connected = true);
-		*/
 	}
 	else
 	{

contrib/pg_dtm/pg_dtm.c

@@ -948,27 +948,20 @@ Datum dtm_join_transaction(PG_FUNCTION_ARGS)
 
 void DtmBackgroundWorker(Datum arg)
 {
-	elog(ERROR, "unix socket not supported yet");
-	// FIXME: implement switching between multiple connections
-	*(int*)0 = 0;
-
-	/*
 	Shub shub;
 	ShubParams params;
 	char unix_sock_path[MAXPGPATH];
 
-	snprintf(unix_sock_path, sizeof(unix_sock_path), "%s/p%d", Unix_socket_directories, DtmPort);
+	snprintf(unix_sock_path, sizeof(unix_sock_path), "%s/sh.unix", Unix_socket_directories);
 
 	ShubInitParams(&params);
 
-	params.host = DtmHost;
-	params.port = DtmPort;
+	params.hosts = DtmServers;
 	params.file = unix_sock_path;
 	params.buffer_size = DtmBufferSize;
 
 	ShubInitialize(&shub, &params);
 	ShubLoop(&shub);
-	*/
 }
 
 static void ByteBufferAlloc(ByteBuffer* buf)