!6287 fix exit core dump

Merge pull request !6287 from kisnwang/fix-exit-core-dump

mindspore/ccsrc/backend/session/executor.cc

@@ -91,6 +91,8 @@ Executor::Executor(const std::string &device_name, uint32_t device_id) {
   worker_ = std::make_shared<std::thread>(&Executor::WorkerLoop, this);
 }
 
+Executor::~Executor() { WorkerJoin(); }
+
 void Executor::CheckException() {
   if (exception_ptr_ != nullptr) {
     auto exception_ptr = exception_ptr_;
@@ -100,8 +102,15 @@ void Executor::CheckException() {
 }
 
 void Executor::WorkerJoin() {
-  StopWorker();
-  worker_->join();
+  if (worker_->joinable()) {
+    {
+      std::unique_lock<std::mutex> lock(task_mutex_);
+      auto task = std::make_shared<ExitTask>();
+      ready_tasks_.push(task);
+      task_cond_var_.notify_all();
+    }
+    worker_->join();
+  }
 }
 
 void Executor::WorkerLoop() {
@@ -282,13 +291,6 @@ bool Executor::DestroyCommGroup(const std::string &group_name) {
   return task->result_;
 }
 
-void Executor::StopWorker() {
-  std::unique_lock<std::mutex> lock(task_mutex_);
-  auto task = std::make_shared<ExitTask>();
-  ready_tasks_.push(task);
-  task_cond_var_.notify_all();
-}
-
 void Executor::OnWorkerExit() {
   if (device_name_ == kAscendDevice) {
     device::KernelRuntimeManager::Instance().ReleaseKernelRuntime(kAscendDevice, device_id_);

mindspore/ccsrc/backend/session/executor.h

@@ -146,7 +146,7 @@ class ExitTask : public Task {
 class Executor {
  public:
   Executor(const std::string &device_name, uint32_t device_id);
-  ~Executor() = default;
+  ~Executor();
   void WorkerLoop();
   void WorkerJoin();
   GraphId CompileGraphAsync(const SessionPtr &session, const AnfNodePtrList &lst, const AnfNodePtrList &outputs);
@@ -168,7 +168,6 @@ class Executor {
   std::vector<std::shared_ptr<RunGraphTask>> GetNewReadyTasks();
   bool IsAllInputsReady(const std::vector<tensor::TensorPtr> &inputs);
   void CheckException();
-  void StopWorker();
   void OnWorkerExit();
 
   uint32_t device_id_;