From abdc9e2ec665686e15af6bf208304be57146918a Mon Sep 17 00:00:00 2001
From: "Joshua Z. Zhang" <cheungchih@gmail.com>
Date: Fri, 3 Aug 2018 15:42:35 -0700
Subject: [PATCH] disable opencv threading for forked process (#12025)

---
 src/initialize.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/initialize.cc b/src/initialize.cc
index 1fd92628e9b2..342b0ee0141b 100644
--- a/src/initialize.cc
+++ b/src/initialize.cc
@@ -26,6 +26,9 @@
 #include <dmlc/logging.h>
 #include <mxnet/engine.h>
 #include "./engine/openmp.h"
+#if MXNET_USE_OPENCV
+#include <opencv2/opencv.hpp>
+#endif  // MXNET_USE_OPENCV
 
 namespace mxnet {
 #if MXNET_USE_SIGNAL_HANDLER && DMLC_LOG_STACK_TRACE
@@ -57,6 +60,9 @@ class LibraryInitializer {
         // Make children single threaded since they are typically workers
         dmlc::SetEnv("MXNET_CPU_WORKER_NTHREADS", 1);
         dmlc::SetEnv("OMP_NUM_THREADS", 1);
+#if MXNET_USE_OPENCV
+        cv::setNumThreads(0);  // disable opencv threading
+#endif  // MXNET_USE_OPENCV
         engine::OpenMP::Get()->set_enabled(false);
         Engine::Get()->Start();
       });