!12192 terminate tbe process pool in separate thread, kill child of fork in 310 model converter

From: @zhoufeng54
Reviewed-by: @xu-yfei,@kisnwang
Signed-off-by: @xu-yfei

mindspore/_extends/parallel_compile/tbe_compiler/tbe_process.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 # ============================================================================
 """tbe process"""
+import threading
 import traceback
 import multiprocessing
 import subprocess
@@ -137,11 +138,16 @@ class TbeProcess:
             res = "TBEException", "ERROR: [MS_BUILD_PROCESS_NUM] type should be a int num, but got :" + process_num
         return res
 
+    def close_pool(self):
+        self.__pool.terminate()
+        self.__pool.join()
+        del self.__pool
+
     def exit(self):
         if self.__pool is not None:
-            self.__pool.terminate()
-            self.__pool.join()
-            del self.__pool
+            stop_thread = threading.Thread(target=self.close_pool)
+            stop_thread.daemon = True
+            stop_thread.start()
 
     def start_compile_op(self, op_json):
         """

mindspore/ccsrc/cxx_api/model/model_converter_utils/multi_process.cc

@@ -65,13 +65,30 @@ Status MultiProcess::MainProcess(ProcessFuncCall parent_process, ProcessFuncCall
   if (pid == 0) {
     ChildProcess(child_process);
     shared_memory.Detach();
-    MS_LOG_INFO << "Model converter: child process exit";
-    exit(0);
+    MS_LOG_INFO << "Model converter: child process sleep waiting for exit signal.";
+    while (1) {
+      // waiting for signal
+    }
   } else {  // parent process
     ret = ParentProcess(parent_process);
     shared_memory.Detach();
-    int status;
-    wait(&status);
+
+    MS_LOG_INFO << "Model converter: parent process kills child of fork.";
+    (void)kill(pid, SIGKILL);
+    constexpr uint32_t kMaxLoopCount = 5;
+    bool child_exited = false;
+    for (uint32_t i = 0; i < kMaxLoopCount; ++i) {
+      int status;
+      if (waitpid(pid, &status, WNOHANG) == pid) {
+        MS_LOG(INFO) << "Child process " << pid << " exits success.";
+        child_exited = true;
+        break;
+      }
+      sleep(1);
+    }
+    if (!child_exited) {
+      MS_LOG(WARNING) << "Child process " << pid << " has been killed but waitpid failed.";
+    }
     shared_memory.Destroy();
   }
   return ret;