!451 use forkserver multiprocess context to avoid forking child process with...

!451 use forkserver multiprocess context to avoid forking child process with locked stream resource(eg stdout)
Merge pull request !451 from wenkai/wk5_fix_log_stream_flush_stuck

mindinsight/utils/computing_resource_mgr.py

@@ -16,6 +16,7 @@
 import fractions
 import math
 import threading
+import multiprocessing
 from concurrent import futures
 
 from mindinsight.utils.log import utils_logger as logger
@@ -23,6 +24,9 @@ from mindinsight.utils.constant import GeneralErrors
 from mindinsight.utils.exceptions import MindInsightException
 
 
+_MP_CONTEXT = multiprocessing.get_context(method="forkserver")
+
+
 class ComputingResourceManager:
     """
     Manager for computing resources.
@@ -44,7 +48,7 @@ class ComputingResourceManager:
             for ind in range(self._executors_cnt)
         }
         self._remaining_executors = len(self._executors)
-        self._backend = futures.ProcessPoolExecutor(max_workers=max_processes_cnt)
+        self._backend = futures.ProcessPoolExecutor(max_workers=max_processes_cnt, mp_context=_MP_CONTEXT)
         logger.info("Initialized ComputingResourceManager with executors_cnt=%s, max_processes_cnt=%s.",
                     executors_cnt, max_processes_cnt)