Addition of server status flags

Addition of dcb role API

core/dcb.c

@@ -509,3 +509,15 @@ va_list	args;
 	buf->end = GWBUF_DATA(buf) + strlen(GWBUF_DATA(buf)) + 1;
 	dcb->func.write(dcb, buf);
 }
+
+/**
+ * Determine the role that a DCB plays within a session.
+ *
+ * @param dcb
+ * @return Non-zero if the DCB is the client of the session
+ */
+int
+dcb_isclient(DCB *dcb)
+{
+	return (dcb->session && dcb == dcb->session->client);
+}

core/depend.mk

@@ -68,7 +68,8 @@ gateway.o: gateway.c ../include/gw.h /usr/include/stdio.h \
  ../include/thread.h /usr/include/pthread.h /usr/include/sched.h \
  /usr/include/bits/sched.h /usr/include/bits/setjmp.h ../include/buffer.h \
  ../include/mysql_protocol.h ../include/dcb.h ../include/service.h \
- ../include/server.h ../include/session.h
+ ../include/server.h ../include/session.h ../include/modules.h \
+ ../include/poll.h
 gateway_mysql_protocol.o: gateway_mysql_protocol.c ../include/gw.h \
  /usr/include/stdio.h /usr/include/features.h /usr/include/sys/cdefs.h \
  /usr/include/bits/wordsize.h /usr/include/gnu/stubs.h \
@@ -350,9 +351,9 @@ server.o: server.c /usr/include/stdio.h /usr/include/features.h \
  /usr/include/bits/time.h /usr/include/sys/sysmacros.h \
  /usr/include/bits/pthreadtypes.h /usr/include/alloca.h \
  /usr/include/string.h /usr/include/xlocale.h ../include/session.h \
- ../include/server.h ../include/spinlock.h ../include/thread.h \
- /usr/include/pthread.h /usr/include/sched.h /usr/include/bits/sched.h \
- /usr/include/bits/setjmp.h ../include/dcb.h ../include/buffer.h
+ ../include/server.h ../include/dcb.h ../include/spinlock.h \
+ ../include/thread.h /usr/include/pthread.h /usr/include/sched.h \
+ /usr/include/bits/sched.h /usr/include/bits/setjmp.h ../include/buffer.h
 poll.o: poll.c /usr/include/stdio.h /usr/include/features.h \
  /usr/include/sys/cdefs.h /usr/include/bits/wordsize.h \
  /usr/include/gnu/stubs.h /usr/include/gnu/stubs-64.h \

core/gateway.c

@@ -38,8 +38,8 @@
 #include <server.h>
 #include <dcb.h>
 #include <session.h>
-
-void myfree(void** pp) { free(*pp); *pp = NULL; }
+#include <modules.h>
+#include <poll.h>
 
 /* basic signal handling */
 static void sighup_handler (int i) {
@@ -167,7 +167,6 @@ main(int argc, char **argv)
 {
 int			daemon_mode = 1;
 sigset_t		sigset;
-int			nfds;
 int			n;
 unsigned short		port = 4406;
 SERVICE			*service1, *service2;
@@ -249,8 +248,6 @@ SERVER			*server1, *server2, *server3;
 	serviceStart(service1);
 	serviceStart(service2);
 
-	fprintf(stderr, ">> GATEWAY poll maxevents is %i\n", MAX_EVENTS);
-
 	while (1)
 	{
 		poll();

core/server.c

@@ -59,6 +59,7 @@ SERVER 	*server;
 	server->protocol = strdup(protocol);
 	server->port = port;
 	memset(&server->stats, sizeof(SERVER_STATS), 0);
+	server->status = 0;
 	server->nextdb = NULL;
 
 	spinlock_acquire(&server_spin);
@@ -165,3 +166,29 @@ SERVER	*ptr;
 	}
 	spinlock_release(&server_spin);
 }
+
+/**
+ * Convert a set of  server status flags to a string, the returned
+ * string has been malloc'd and must be free'd by the caller
+ *
+ * @param SERVER The server to return the status of
+ * @return A string representation of the status flags
+ */
+char *
+server_status(SERVER *server)
+{
+char	*status = NULL;
+
+	if ((status = (char *)malloc(200)) == NULL)
+		return NULL;
+	status[0] = 0;
+	if (server->status & SERVER_RUNNING)
+		strcat(status, "Running, ");
+	else
+		strcat(status, "Down, ");
+	if (server->status & SERVER_MASTER)
+		strcat(status, "Master");
+	else
+		strcat(status, "Slave");
+	return status;
+}

core/session.c

@@ -66,9 +66,16 @@ SESSION 	*session;
 	session->state = SESSION_STATE_ALLOC;
 	client->session = session;
 
-	// this will prevent the connect()  backends via connect_dcb() for listening socket
+	/*
+	 * Only create a router session if we are not the listening 
+	 * DCB. Creating a router session may create a connection to a
+	 * backend server, depending upon the router module implementation
+	 * and should be avoided for the listener session
+	 */
 	if (client->state != DCB_STATE_LISTENING)
+	{
 		session->router_session = service->router->newSession(service->router_instance, session);
+	}
 
 	spinlock_acquire(&session_spin);
 	session->next = allSessions;

include/dcb.h

@@ -142,5 +142,6 @@ extern void		dprintAllDCBs(DCB *);		/* Debug to print all DCB in the system */
 extern void		dprintDCB(DCB *, DCB *);	/* Debug to print a DCB in the system */
 extern const char 	*gw_dcb_state2string(int);	/* DCB state to string */
 extern void		dcb_printf(DCB *, const char *, ...);	/* DCB version of printf */
+extern int		dcb_isclient(DCB *);
 
 #endif

include/gw.h

@@ -19,7 +19,6 @@
 
 #include <stdbool.h>
 
-#define MAX_EVENTS 1000000
 #define EXIT_FAILURE 1
 
 // network buffer is 32K

include/server.h

@@ -29,6 +29,7 @@
  *
  * Date		Who		Description
  * 14/06/13	Mark Riddoch	Initial implementation
+ * 21/06/13	Mark Riddoch	Addition of server status flags
  *
  * @endverbatim
  */
@@ -51,14 +52,20 @@ typedef struct server {
 	char		*name;		/**< Server name/IP address*/
 	unsigned short	port;		/**< Port to listen on */
 	char		*protocol;	/**< Protocol module to use */
+	unsigned int	status;		/**< Status flag bitmap for the server */
 	SERVER_STATS	stats;		/**< The server statistics */
 	struct	server	*next;		/**< Next server */
-	struct	server	*nextdb;	/**< Next server in lsit attached to a service */
+	struct	server	*nextdb;	/**< Next server in list attached to a service */
 } SERVER;
 
+#define	SERVER_RUNNING	0x0001		/**<< The server is up and running */
+#define SERVER_MASTER	0x0002		/**<< The server is a master, i.e. can handle writes */
+
+
 extern SERVER	*server_alloc(char *, char *, unsigned short);
 extern int	server_free(SERVER *);
 extern void	printServer(SERVER *);
 extern void	printAllServers();
 extern void	dprintAllServers(DCB *);
+extern char	*server_status(SERVER *);
 #endif