fix(stream): fix memory leak.

include/libs/stream/tstream.h

@@ -337,6 +337,7 @@ struct SStreamTask {
   SMsgCb*       pMsgCb;  // msg handle
   SStreamState* pState;  // state backend
   SArray*       pRspMsgList;
+  TdThreadMutex lock;
 
   // the followings attributes don't be serialized
   int32_t             notReadyTasks;

source/dnode/snode/src/snode.c

@@ -91,6 +91,7 @@ int32_t sndExpandTask(SSnode *pSnode, SStreamTask *pTask, int64_t ver) {
   pTask->exec.pExecutor = qCreateStreamExecTaskInfo(pTask->exec.qmsg, &handle, 0);
   ASSERT(pTask->exec.pExecutor);
 
+  taosThreadMutexInit(&pTask->lock, NULL);
   streamSetupScheduleTrigger(pTask);
 
   qDebug("snode:%d expand stream task on snode, s-task:%s, checkpoint ver:%" PRId64 " child id:%d, level:%d", SNODE_HANDLE,

source/dnode/vnode/src/tq/tq.c

@@ -921,6 +921,7 @@ int32_t tqExpandTask(STQ* pTq, SStreamTask* pTask, int64_t ver) {
     pTask->status.taskStatus = TASK_STATUS__NORMAL;
   }
 
+  taosThreadMutexInit(&pTask->lock, NULL);
   streamSetupScheduleTrigger(pTask);
 
   tqInfo("vgId:%d expand stream task, s-task:%s, checkpoint ver:%" PRId64

source/libs/stream/src/streamDispatch.c

@@ -691,10 +691,11 @@ int32_t streamAddEndScanHistoryMsg(SStreamTask* pTask, SRpcHandleInfo* pRpcInfo,
   initRpcMsg(&info.msg, 0, pBuf, sizeof(SMsgHead) + len);
   info.msg.info = *pRpcInfo;
 
-  // todo: fix race condition here
+  taosThreadMutexLock(&pTask->lock);
   if (pTask->pRspMsgList == NULL) {
     pTask->pRspMsgList = taosArrayInit(4, sizeof(SStreamContinueExecInfo));
   }
+  taosThreadMutexUnlock(&pTask->lock);
 
   taosArrayPush(pTask->pRspMsgList, &info);
 

source/libs/stream/src/streamTask.c

@@ -251,5 +251,10 @@ void tFreeStreamTask(SStreamTask* pTask) {
     tSimpleHashCleanup(pTask->pNameMap);
   }
 
+  if (pTask->pRspMsgList != NULL) {
+    pTask->pRspMsgList = taosArrayDestroy(pTask->pRspMsgList);
+  }
+
+  taosThreadMutexDestroy(&pTask->lock);
   taosMemoryFree(pTask);
 }