Add some comment for the usage of MetaLockUtils

apache · Dec 3, 2020 · 17c0d45 · 17c0d45
1 parent 0df43a0
commit 17c0d45
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/common/util/MetaLockUtils.java b/fe/fe-core/src/main/java/org/apache/doris/common/util/MetaLockUtils.java
@@ -23,6 +23,11 @@
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
+/**
+ * MetaLockUtils is a helper class to lock and unlock all meta object in a list.
+ * In order to escape dead lock, meta object in list should be sorted in ascending
+ * order by id first, and then MetaLockUtils can lock them.
+ */
 public class MetaLockUtils {
 
     public static void readLockDatabases(List<Database> databaseList) {