fix hang

Signed-off-by: Tim Vaillancourt <tim@timvaillancourt.com>

Author: timvaillancourt

go/vt/vtorc/logic/tablet_discovery.go

@@ -99,10 +99,10 @@ func hasShardInKeyRanges(shard string, keyRanges []*topodatapb.KeyRange) (bool,
 // getKeyspaceShardsToWatch converts the input clustersToWatch into a list of individual keyspace/shards.
 func getKeyspaceShardsToWatch() ([]*topo.KeyspaceShard, error) {
 	var keyspaceShards []*topo.KeyspaceShard
-	keyspaceWatchKeyRanges := make(map[string][]*topodatapb.KeyRange)
+	keyspaceWatchKeyRanges := make(map[string][]*topodatapb.KeyRange, 0)
 	for _, clusterToWatch := range clustersToWatch {
 		var err error
-		var keyRange *topodatapb.KeyRange
+		keyRange := &topodatapb.KeyRange{}
 		keyspace := clusterToWatch
 		if strings.Contains(clusterToWatch, "/") {
 			var shard string
@@ -143,11 +143,11 @@ func getKeyspaceShardsToWatch() ([]*topo.KeyspaceShard, error) {
 					log.Errorf("Failed to parse key ranges for shard %q: %+v", s, err)
 				} else if found {
 					keyspaceShardsMu.Lock()
-					defer keyspaceShardsMu.Unlock()
 					keyspaceShards = append(keyspaceShards, &topo.KeyspaceShard{
 						Keyspace: keyspace,
 						Shard:    s,
 					})
+					keyspaceShardsMu.Unlock()
 				}
 			}
 			return nil
@@ -157,10 +157,6 @@ func getKeyspaceShardsToWatch() ([]*topo.KeyspaceShard, error) {
 		return nil, err
 	}
 
-	slices.SortStableFunc(keyspaceShards, func(a, b *topo.KeyspaceShard) int {
-		return strings.Compare(a.String(), b.String())
-	})
-
 	return keyspaceShards, nil
 }
 

go/vt/vtorc/logic/tablet_discovery_test.go

@@ -19,6 +19,8 @@ package logic
 import (
 	"context"
 	"fmt"
+	"slices"
+	"strings"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -396,6 +398,13 @@ func TestGetKeyspaceShardsToWatch(t *testing.T) {
 			clustersToWatch = testcase.clusters
 			res, err := getKeyspaceShardsToWatch()
 
+			slices.SortStableFunc(res, func(a, b *topo.KeyspaceShard) int {
+				return strings.Compare(a.String(), b.String())
+			})
+			slices.SortStableFunc(testcase.expected, func(a, b *topo.KeyspaceShard) int {
+				return strings.Compare(a.String(), b.String())
+			})
+
 			assert.NoError(t, err)
 			assert.ElementsMatch(t, testcase.expected, res)
 		})