Tests are passing! YAY!

Former-commit-id: e300f753c58fc542267536cd90c1a6b970d83539

src/config.c

@@ -857,6 +857,10 @@ void loadServerConfigFromString(char *config) {
                 server.fActiveReplica = CONFIG_DEFAULT_ACTIVE_REPLICA;
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"multi-master") && argc == 2){
+            if ((server.enable_multimaster = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
         } else {
             err = "Bad directive or wrong number of arguments"; goto loaderr;
         }
@@ -1336,6 +1340,8 @@ void configSetCommand(client *c) {
       "loglevel",server.verbosity,loglevel_enum) {
     } config_set_enum_field(
       "maxmemory-policy",server.maxmemory_policy,maxmemory_policy_enum) {
+    } config_set_bool_field(
+       "multi-master", server.enable_multimaster) {
     } config_set_enum_field(
       "appendfsync",server.aof_fsync,aof_fsync_enum) {
 
@@ -2378,6 +2384,7 @@ int rewriteConfig(char *path) {
     rewriteConfigYesNoOption(state,"replica-lazy-flush",server.repl_slave_lazy_flush,CONFIG_DEFAULT_SLAVE_LAZY_FLUSH);
     rewriteConfigYesNoOption(state,"dynamic-hz",server.dynamic_hz,CONFIG_DEFAULT_DYNAMIC_HZ);
     rewriteConfigYesNoOption(state,"active-replica",server.fActiveReplica,CONFIG_DEFAULT_ACTIVE_REPLICA);
+    rewriteConfigYesNoOption(state,"multi-master",server.enable_multimaster,CONFIG_DEFAULT_ENABLE_MULTIMASTER);
 
     /* Rewrite Sentinel config if in Sentinel mode. */
     if (server.sentinel_mode) rewriteConfigSentinelOption(state);

src/replication.cpp

@@ -1231,6 +1231,7 @@ void replicationEmptyDbCallback(void *privdata) {
  * performed, this function materializes the master client we store
  * at server.master, starting from the specified file descriptor. */
 void replicationCreateMasterClient(redisMaster *mi, int fd, int dbid) {
+    serverAssert(mi->master == nullptr);
     mi->master = createClient(fd, serverTL - server.rgthreadvar);
     mi->master->flags |= CLIENT_MASTER;
     mi->master->authenticated = 1;
@@ -1248,8 +1249,6 @@ void replicationCreateMasterClient(redisMaster *mi, int fd, int dbid) {
     if (mi->master->reploff == -1)
         mi->master->flags |= CLIENT_PRE_PSYNC;
     if (dbid != -1) selectDb(mi->master,dbid);
-
-    listAddNodeTail(server.masters, mi);
 }
 
 /* This function will try to re-enable the AOF file after the
@@ -2163,9 +2162,29 @@ int cancelReplicationHandshake(redisMaster *mi) {
 
 /* Set replication to the specified master address and port. */
 struct redisMaster *replicationAddMaster(char *ip, int port) {
-    redisMaster *mi = (redisMaster*)zcalloc(sizeof(redisMaster), MALLOC_LOCAL);
-    initMasterInfo(mi);
-    int was_master = mi->masterhost == NULL;
+    // pre-reqs: We must not already have a replica in the list with the same tuple
+    listIter li;
+    listNode *ln;
+    listRewind(server.masters, &li);
+    while ((ln = listNext(&li)))
+    {
+        redisMaster *miCheck = (redisMaster*)listNodeValue(ln);
+        serverAssert(strcasecmp(miCheck->masterhost, ip) || miCheck->masterport != port);
+    }
+
+    // Pre-req satisfied, lets continue
+    int was_master = listLength(server.masters) == 0;
+    redisMaster *mi = nullptr;
+    if (!server.enable_multimaster && listLength(server.masters)) {
+        serverAssert(listLength(server.masters) == 1);
+        mi = (redisMaster*)listNodeValue(listFirst(server.masters));
+    }
+    else
+    {
+        mi = (redisMaster*)zcalloc(sizeof(redisMaster), MALLOC_LOCAL);
+        initMasterInfo(mi);
+        listAddNodeTail(server.masters, mi);
+    }
 
     sdsfree(mi->masterhost);
     mi->masterhost = sdsnew(ip);
@@ -2186,14 +2205,14 @@ struct redisMaster *replicationAddMaster(char *ip, int port) {
      * our own parameters, to later PSYNC with the new master. */
     if (was_master) replicationCacheMasterUsingMyself(mi);
     mi->repl_state = REPL_STATE_CONNECT;
-    listAddNodeTail(server.masters, mi);
     return mi;
 }
 
 /* Cancel replication, setting the instance as a master itself. */
 void replicationUnsetMaster(redisMaster *mi) {
-    if (mi->masterhost == NULL) return; /* Nothing to do. */
+    serverAssert(mi->masterhost != NULL);
     sdsfree(mi->masterhost);
+    
     mi->masterhost = NULL;
     /* When a slave is turned into a master, the current replication ID
      * (that was inherited from the master at synchronization time) is
@@ -2226,6 +2245,10 @@ void replicationUnsetMaster(redisMaster *mi) {
      * starting from now. Otherwise the backlog will be freed after a
      * failover if slaves do not connect immediately. */
     server.repl_no_slaves_since = server.unixtime;
+
+    listNode *ln = listSearchKey(server.masters, mi);
+    serverAssert(ln != nullptr);
+    listDelNode(server.masters, ln);
 }
 
 /* This function is called when the slave lose the connection with the
@@ -2252,12 +2275,9 @@ void replicaofCommand(client *c) {
     if (!strcasecmp((const char*)ptrFromObj(c->argv[1]),"no") &&
         !strcasecmp((const char*)ptrFromObj(c->argv[2]),"one")) {
         if (listLength(server.masters)) {
-            listIter li;
-            listNode *ln;
-            listRewind(server.masters, &li);
-            while ((ln = listNext(&li)))
+            while (listLength(server.masters))
             {
-                replicationUnsetMaster((redisMaster*)listNodeValue(ln));
+                replicationUnsetMaster((redisMaster*)listNodeValue(listFirst(server.masters)));
             }
             sds client = catClientInfoString(sdsempty(),c);
             serverLog(LL_NOTICE,"MASTER MODE enabled (user request from '%s')",

src/server.cpp

@@ -2279,6 +2279,9 @@ void initServerConfig(void) {
     server.runid[CONFIG_RUN_ID_SIZE] = '\0';
     changeReplicationId();
     clearReplicationId2();
+    server.clients = listCreate();
+    server.slaves = listCreate();
+    server.monitors = listCreate();
     server.timezone = getTimeZone(); /* Initialized by tzset(). */
     server.configfile = NULL;
     server.executable = NULL;
@@ -2397,6 +2400,7 @@ void initServerConfig(void) {
 
     /* Replication related */
     server.masters = listCreate();
+    server.enable_multimaster = CONFIG_DEFAULT_ENABLE_MULTIMASTER;
     server.repl_syncio_timeout = CONFIG_REPL_SYNCIO_TIMEOUT;
     server.repl_serve_stale_data = CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA;
     server.repl_slave_ro = CONFIG_DEFAULT_SLAVE_READ_ONLY;
@@ -2858,11 +2862,8 @@ void initServer(void) {
     server.hz = server.config_hz;
     server.pid = getpid();
     server.current_client = NULL;
-    server.clients = listCreate();
     server.clients_index = raxNew();
     server.clients_to_close = listCreate();
-    server.slaves = listCreate();
-    server.monitors = listCreate();
     server.slaveseldb = -1; /* Force to emit the first SELECT command. */
     server.ready_keys = listCreate();
     server.clients_waiting_acks = listCreate();

src/server.h

@@ -188,6 +188,7 @@ extern "C" {
 #define CONFIG_DEFAULT_THREAD_AFFINITY 0
 
 #define CONFIG_DEFAULT_ACTIVE_REPLICA 0
+#define CONFIG_DEFAULT_ENABLE_MULTIMASTER 0
 
 #define ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP 20 /* Loopkups per loop. */
 #define ACTIVE_EXPIRE_CYCLE_FAST_DURATION 1000 /* Microseconds */
@@ -1326,6 +1327,7 @@ struct redisServer {
     int repl_diskless_sync_delay;   /* Delay to start a diskless repl BGSAVE. */
     /* Replication (slave) */
     list *masters;
+    int enable_multimaster; 
     int repl_timeout;               /* Timeout after N seconds of master idle */
     int repl_syncio_timeout; /* Timeout for synchronous I/O calls */
     int repl_disable_tcp_nodelay;   /* Disable TCP_NODELAY after SYNC? */

tests/support/util.tcl

@@ -48,7 +48,7 @@ proc warnings_from_file {filename} {
 
 # Return value for INFO property
 proc status {r property} {
-    if {[regexp "\r\n$property:(.*?)\r\n" [{*}$r info] _ value]} {
+    if {[regexp "\r\n(\t*?)$property:(.*?)\r\n" [{*}$r info] _ __ value]} {
         set _ $value
     }
 }