Document safe cache invalidation in SqlTaskManager

trinodb · Jan 21, 2022 · 51f18a1 · 51f18a1
1 parent f2c3d1d
commit 51f18a1
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/core/trino-main/src/main/java/io/trino/execution/SqlTaskManager.java b/core/trino-main/src/main/java/io/trino/execution/SqlTaskManager.java
@@ -500,6 +500,8 @@ void removeOldTasks()
                     try {
                         DateTime endTime = taskInfo.getStats().getEndTime();
                         if (endTime != null && endTime.isBefore(oldestAllowedTask)) {
+                            // The removal here is concurrency safe with respect to any concurrent loads: the cache has no expiration,
+                            // the taskId is in the cache, so there mustn't be an ongoing load.
                             tasks.asMap().remove(taskId);
                         }
                     }