From 241f8b3d2e733c7ba7420edb5923e44c4c1b5e05 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Tue, 14 May 2024 18:05:13 +0800
Subject: [PATCH] fix(tsdb): fix deadlock when stopping reader.

---
 source/libs/executor/src/executor.c | 17 ++++++++++-------
 source/libs/stream/src/streamMeta.c |  2 ++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/source/libs/executor/src/executor.c b/source/libs/executor/src/executor.c
index 29f667cb66..2f360044c9 100644
--- a/source/libs/executor/src/executor.c
+++ b/source/libs/executor/src/executor.c
@@ -824,14 +824,17 @@ int32_t qKillTask(qTaskInfo_t tinfo, int32_t rspCode) {
   qDebug("%s sync killed execTask", GET_TASKID(pTaskInfo));
   setTaskKilled(pTaskInfo, TSDB_CODE_TSC_QUERY_KILLED);
 
-  taosWLockLatch(&pTaskInfo->lock);
-  while (qTaskIsExecuting(pTaskInfo)) {
-    taosMsleep(10);
+  while(1) {
+    taosWLockLatch(&pTaskInfo->lock);
+    if (qTaskIsExecuting(pTaskInfo)) { // let's wait for 100 ms and try again
+      taosWUnLockLatch(&pTaskInfo->lock);
+      taosMsleep(100);
+    } else { // not running now
+      pTaskInfo->code = rspCode;
+      taosWUnLockLatch(&pTaskInfo->lock);
+      return TSDB_CODE_SUCCESS;
+    }
   }
-  pTaskInfo->code = rspCode;
-  taosWUnLockLatch(&pTaskInfo->lock);
-
-  return TSDB_CODE_SUCCESS;
 }
 
 bool qTaskIsExecuting(qTaskInfo_t qinfo) {
diff --git a/source/libs/stream/src/streamMeta.c b/source/libs/stream/src/streamMeta.c
index 4fa9b2c66f..0aace1cb5b 100644
--- a/source/libs/stream/src/streamMeta.c
+++ b/source/libs/stream/src/streamMeta.c
@@ -1631,6 +1631,8 @@ int32_t streamMetaAddFailedTask(SStreamMeta* pMeta, int64_t streamId, int32_t ta
       streamMetaAddTaskLaunchResult(pMeta, hId.streamId, hId.taskId, startTs, now, false);
     }
   } else {
+    streamMetaRUnLock(pMeta);
+
     stError("failed to locate the stream task:0x%" PRIx64 "-0x%x (vgId:%d), it may have been destroyed or stopped",
             streamId, taskId, pMeta->vgId);
     code = TSDB_CODE_STREAM_TASK_NOT_EXIST;