fix(stream): fix bug in checkpoint.

include/libs/stream/tstream.h

@@ -368,7 +368,7 @@ typedef struct SStreamMeta {
   TdThreadMutex backendMutex;
 
 //  uint64_t checkpointId;
-  int32_t  notCkptReadyTasks;
+  int32_t  chkptNotReadyTasks;
   SArray*  checkpointSaved;
   SArray*  checkpointInUse;
   int32_t  checkpointCap;

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

@@ -1523,6 +1523,12 @@ int32_t tqProcessStreamCheckPointSourceReq(STQ* pTq, int64_t sversion, char* pMs
   memcpy(pRpcMsg, (SRpcMsg*)pMsg, sizeof(SRpcMsg));
   taosArrayPush(pTask->pRpcMsgList, &pRpcMsg);
 
+  // todo: when generating checkpoint, no new tasks are allowed to add into current Vnode
+  // set the initial value for generating check point
+  taosWLockLatch(&pMeta->lock);
+  pMeta->chkptNotReadyTasks = taosArrayGetSize(pMeta->pTaskList);
+  taosWUnLockLatch(&pMeta->lock);
+
   streamProcessCheckpointSourceReq(pMeta, pTask, &req);
   streamMetaReleaseTask(pMeta, pTask);
   return code;

source/libs/stream/src/streamExec.c

@@ -536,8 +536,10 @@ int32_t streamTryExec(SStreamTask* pTask) {
       // check for all tasks, and do generate the vnode-wide checkpoint data.
       // todo extract method
       SStreamMeta* pMeta = pTask->pMeta;
-      int32_t remain = atomic_sub_fetch_32(&pMeta->notCkptReadyTasks, 1);
-      if (remain <= 0) {  // all tasks are in TASK_STATUS__CK_READY state
+      int32_t remain = atomic_sub_fetch_32(&pMeta->chkptNotReadyTasks, 1);
+      ASSERT(remain >= 0);
+
+      if (remain == 0) {  // all tasks are in TASK_STATUS__CK_READY state
         streamBackendDoCheckpoint(pMeta, pTask->checkpointingId);
       }