refactor DoRefreshRemoteHandles a bit to get rid of compiler warnings

As written originally, the branching confused the compiler enough to
emit warning about using uninitialized allOids variable. Refactor the
code a bit to make it clear that's not really possible, and also move
a number of variable declarations from the function scope to a block
level.

Note: I think the function would deserve more documentation - both
about the intent in general, and about the meaning of the return
value ('res' is quite unclear name).

diff --git a/src/backend/pgxc/pool/pgxcnode.c b/src/backend/pgxc/pool/pgxcnode.c
index 40d718c52d3511409e31f1f449dc39c3ab7f4a27..cc5df6963e0a74a253d9e3bef19178fa2f0a9103 100644 (file)
--- a/src/backend/pgxc/pool/pgxcnode.c
+++ b/src/backend/pgxc/pool/pgxcnode.c
@@ -2884,12 +2884,8 @@ static bool
 DoRefreshRemoteHandles(void)
 {
        List                    *altered = NIL, *deleted = NIL, *added = NIL;
-       List                    *shmoids = NIL;
-       Oid                             *coOids, *dnOids, *allOids, nodeoid;
-       int                             numDNodes;
-       int                             i, numCoords, total_nodes;
-       NodeDefinition  *nodeDef;
-       PGXCNodeHandle  *handle;
+       Oid                             *coOids, *dnOids;
+       int                             numCoords, numDNodes, total_nodes;
        bool                    res = true;
 
        HandlesRefreshPending = false;
@@ -2899,107 +2895,114 @@ DoRefreshRemoteHandles(void)
        total_nodes = numCoords + numDNodes;
        if (total_nodes > 0)
        {
-               allOids = (Oid *)palloc(total_nodes * sizeof(Oid));
+               int             i;
+               List   *shmoids = NIL;
+               Oid        *allOids = (Oid *)palloc(total_nodes * sizeof(Oid));
 
-               for (i = 0; i < numCoords; i++)
-                       allOids[i] = coOids[i];
+               /* build array with Oids of all nodes (coordinators first) */
+               memcpy(allOids, coOids, numCoords * sizeof(Oid));
+               memcpy(allOids + numCoords, dnOids, numDNodes * sizeof(Oid));
 
-               for (i = 0; i + numCoords < total_nodes; i++)
-                       allOids[i + numCoords] = dnOids[i];
-       }
+               LWLockAcquire(NodeTableLock, LW_SHARED);
 
-       LWLockAcquire(NodeTableLock, LW_SHARED);
-       for (i = 0; i < total_nodes; i++)
-       {
-               int nid;
-               Oid nodeoid;
-               char ntype = PGXC_NODE_NONE;
+               for (i = 0; i < total_nodes; i++)
+               {
+                       NodeDefinition  *nodeDef;
+                       PGXCNodeHandle  *handle;
 
-               nodeoid = allOids[i];
-               shmoids = lappend_oid(shmoids, nodeoid);
+                       int nid;
+                       Oid nodeoid;
+                       char ntype = PGXC_NODE_NONE;
 
-               nodeDef = PgxcNodeGetDefinition(nodeoid);
-               /*
-                * identify an entry with this nodeoid. If found
-                * compare the name/host/port entries. If the name is
-                * same and other info is different, it's an ALTER.
-                * If the local entry does not exist in the shmem, it's
-                * a DELETE. If the entry from shmem does not exist
-                * locally, it's an ADDITION
-                */
-               nid = PGXCNodeGetNodeId(nodeoid, &ntype);
-
-               if (nid == -1)
-               {
-                       /* a new node has been added to the shmem */
-                       added = lappend_oid(added, nodeoid);
-                       elog(LOG, "Node added: name (%s) host (%s) port (%d)",
-                                NameStr(nodeDef->nodename), NameStr(nodeDef->nodehost),
-                                nodeDef->nodeport);
-               }
-               else
-               {
-                       if (ntype == PGXC_NODE_COORDINATOR)
-                               handle = &co_handles[nid];
-                       else if (ntype == PGXC_NODE_DATANODE)
-                               handle = &dn_handles[nid];
-                       else
-                               elog(ERROR, "Node with non-existent node type!");
+                       nodeoid = allOids[i];
+                       shmoids = lappend_oid(shmoids, nodeoid);
 
+                       nodeDef = PgxcNodeGetDefinition(nodeoid);
                        /*
-                        * compare name, host, port to see if this node
-                        * has been ALTERed
+                        * identify an entry with this nodeoid. If found
+                        * compare the name/host/port entries. If the name is
+                        * same and other info is different, it's an ALTER.
+                        * If the local entry does not exist in the shmem, it's
+                        * a DELETE. If the entry from shmem does not exist
+                        * locally, it's an ADDITION
                         */
-                       if (strncmp(handle->nodename, NameStr(nodeDef->nodename), NAMEDATALEN)
-                               != 0 ||
-                               strncmp(handle->nodehost, NameStr(nodeDef->nodehost), NAMEDATALEN)
-                               != 0 ||
-                               handle->nodeport != nodeDef->nodeport)
+                       nid = PGXCNodeGetNodeId(nodeoid, &ntype);
+
+                       if (nid == -1)
                        {
-                               elog(LOG, "Node altered: old name (%s) old host (%s) old port (%d)"
-                                               " new name (%s) new host (%s) new port (%d)",
-                                        handle->nodename, handle->nodehost, handle->nodeport,
+                               /* a new node has been added to the shmem */
+                               added = lappend_oid(added, nodeoid);
+                               elog(LOG, "Node added: name (%s) host (%s) port (%d)",
                                         NameStr(nodeDef->nodename), NameStr(nodeDef->nodehost),
                                         nodeDef->nodeport);
-                               altered = lappend_oid(altered, nodeoid);
                        }
-                       /* else do nothing */
+                       else
+                       {
+                               if (ntype == PGXC_NODE_COORDINATOR)
+                                       handle = &co_handles[nid];
+                               else if (ntype == PGXC_NODE_DATANODE)
+                                       handle = &dn_handles[nid];
+                               else
+                                       elog(ERROR, "Node with non-existent node type!");
+
+                               /*
+                                * compare name, host, port to see if this node
+                                * has been ALTERed
+                                */
+                               if (strncmp(handle->nodename, NameStr(nodeDef->nodename), NAMEDATALEN) != 0 ||
+                                       strncmp(handle->nodehost, NameStr(nodeDef->nodehost), NAMEDATALEN) != 0 ||
+                                       handle->nodeport != nodeDef->nodeport)
+                               {
+                                       elog(LOG, "Node altered: old name (%s) old host (%s) old port (%d)"
+                                                       " new name (%s) new host (%s) new port (%d)",
+                                                handle->nodename, handle->nodehost, handle->nodeport,
+                                                NameStr(nodeDef->nodename), NameStr(nodeDef->nodehost),
+                                                nodeDef->nodeport);
+                                       altered = lappend_oid(altered, nodeoid);
+                               }
+                               /* else do nothing */
+                       }
+                       pfree(nodeDef);
                }
-               pfree(nodeDef);
-       }
 
-       /*
-        * Any entry in backend area but not in shmem means that it has
-        * been deleted
-        */
-       for (i = 0; i < NumCoords; i++)
-       {
-               handle = &co_handles[i];
-               nodeoid = handle->nodeoid;
-               if (!list_member_oid(shmoids, nodeoid))
+               /*
+                * Any entry in backend area but not in shmem means that it has
+                * been deleted
+                */
+               for (i = 0; i < NumCoords; i++)
                {
-                       deleted = lappend_oid(deleted, nodeoid);
-                       elog(LOG, "Node deleted: name (%s) host (%s) port (%d)",
-                                handle->nodename, handle->nodehost, handle->nodeport);
+                       PGXCNodeHandle  *handle = &co_handles[i];
+                       Oid nodeoid = handle->nodeoid;
+
+                       if (!list_member_oid(shmoids, nodeoid))
+                       {
+                               deleted = lappend_oid(deleted, nodeoid);
+                               elog(LOG, "Node deleted: name (%s) host (%s) port (%d)",
+                                        handle->nodename, handle->nodehost, handle->nodeport);
+                       }
                }
-       }
-       for (i = 0; i < NumDataNodes; i++)
-       {
-               handle = &dn_handles[i];
-               nodeoid = handle->nodeoid;
-               if (!list_member_oid(shmoids, nodeoid))
+
+               for (i = 0; i < NumDataNodes; i++)
                {
-                       deleted = lappend_oid(deleted, nodeoid);
-                       elog(LOG, "Node deleted: name (%s) host (%s) port (%d)",
-                                handle->nodename, handle->nodehost, handle->nodeport);
+                       PGXCNodeHandle  *handle = &dn_handles[i];
+                       Oid nodeoid = handle->nodeoid;
+
+                       if (!list_member_oid(shmoids, nodeoid))
+                       {
+                               deleted = lappend_oid(deleted, nodeoid);
+                               elog(LOG, "Node deleted: name (%s) host (%s) port (%d)",
+                                        handle->nodename, handle->nodehost, handle->nodeport);
+                       }
                }
-       }
-       LWLockRelease(NodeTableLock);
 
-       /* Release palloc'ed memory */
-       pfree(coOids);
-       pfree(dnOids);
-       pfree(allOids);
+               LWLockRelease(NodeTableLock);
+
+               /* Release palloc'ed memory */
+               pfree(coOids);
+               pfree(dnOids);
+               pfree(allOids);
+               list_free(shmoids);
+       }
 
        if (deleted != NIL || added != NIL)
        {
@@ -3015,10 +3018,10 @@ DoRefreshRemoteHandles(void)
        else
                PgxcNodeRefreshBackendHandlesShmem(altered);
 
-       list_free(shmoids);
        list_free(altered);
        list_free(added);
        list_free(deleted);
+
        return res;
 }