[incubator-mxnet] branch v1.4.x updated: Backporting the fix to v1.4.x branch to prevent the crash in naive engine. (#15154)

[zh...@apache.org]

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zhasheng pushed a commit to branch v1.4.x
in repository https://gitbox.apache.org/repos/asf/incubator-mxnet.git


The following commit(s) were added to refs/heads/v1.4.x by this push:
     new b241c41  Backporting the fix to v1.4.x branch to prevent the crash in naive engine. (#15154)
b241c41 is described below

commit b241c41d66081d330fe08c81b6351cdd76234ec6
Author: Amol Lele <19...@users.noreply.github.com>
AuthorDate: Wed Jun 5 10:11:17 2019 -0700

    Backporting the fix to v1.4.x branch to prevent the crash in naive engine. (#15154)
---
 src/engine/naive_engine.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/engine/naive_engine.cc b/src/engine/naive_engine.cc
index 05b72d2..5472db4 100644
--- a/src/engine/naive_engine.cc
+++ b/src/engine/naive_engine.cc
@@ -62,6 +62,8 @@ class NaiveEngine final : public Engine {
   };
 
   NaiveEngine() {
+    objpool_opr_ref_ = common::ObjectPool<NaiveOpr>::_GetSharedRef();
+    objpool_var_ref_ = common::ObjectPool<NaiveVar>::_GetSharedRef();
   }
   // virtual destructor
   virtual ~NaiveEngine() {
@@ -220,6 +222,13 @@ class NaiveEngine final : public Engine {
   mshadow::Stream<cpu> cpu_stream_;
   // GPU streams
   std::vector<mshadow::Stream<gpu>*> streams_;
+  /*!
+ * \brief Holding a shared_ptr to the object pool to prevent it from being destructed too early
+ * See also #309 (https://github.com/dmlc/mxnet/issues/309) and similar fix in threaded_engine.h.
+ * Without this, segfaults seen on CentOS7 in test_operator_gpu.py:test_convolution_multiple_streams
+ */
+  std::shared_ptr<common::ObjectPool<NaiveOpr> > objpool_opr_ref_;
+  std::shared_ptr<common::ObjectPool<NaiveVar> > objpool_var_ref_;
 };  // class NaiveEngine
 
 Engine *CreateNaiveEngine() {