From f4ec8edea8a8396e1b744db9ea61de2c451bd15d Mon Sep 17 00:00:00 2001
From: Rasmus Munk Larsen <rmlarsen@google.com>
Date: Wed, 6 Mar 2019 11:52:04 -0800
Subject: [PATCH] Add macro EIGEN_AVOID_THREAD_LOCAL to make it possible to
 manually disable the use of thread_local.

---
 unsupported/Eigen/CXX11/src/ThreadPool/ThreadLocal.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/unsupported/Eigen/CXX11/src/ThreadPool/ThreadLocal.h b/unsupported/Eigen/CXX11/src/ThreadPool/ThreadLocal.h
index 7229839ac..696c2d03b 100644
--- a/unsupported/Eigen/CXX11/src/ThreadPool/ThreadLocal.h
+++ b/unsupported/Eigen/CXX11/src/ThreadPool/ThreadLocal.h
@@ -10,6 +10,14 @@
 #ifndef EIGEN_CXX11_THREADPOOL_THREAD_LOCAL_H
 #define EIGEN_CXX11_THREADPOOL_THREAD_LOCAL_H
 
+#ifdef EIGEN_AVOID_THREAD_LOCAL
+
+#ifdef EIGEN_THREAD_LOCAL
+#undef EIGEN_THREAD_LOCAL
+#endif
+
+#else
+
 #if EIGEN_MAX_CPP_VER >= 11 &&                         \
     ((EIGEN_COMP_GNUC && EIGEN_GNUC_AT_LEAST(4, 8)) || \
      __has_feature(cxx_thread_local)                || \
@@ -52,4 +60,6 @@
 #endif
 #endif  // defined(__ANDROID__) && defined(__clang__)
 
+#endif // EIGEN_AVOID_THREAD_LOCAL
+
 #endif  // EIGEN_CXX11_THREADPOOL_THREAD_LOCAL_H