From f28342c2caab42987e6761abeca84ba3147cddba Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <gardener@tensorflow.org>
Date: Wed, 18 Apr 2018 13:13:02 -0700
Subject: Prevent access to deallocated hash map upon exit().

PiperOrigin-RevId: 193404950
---
 tensorflow/core/lib/strings/numbers.cc | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

(limited to 'tensorflow/core/lib/strings/numbers.cc')

diff --git a/tensorflow/core/lib/strings/numbers.cc b/tensorflow/core/lib/strings/numbers.cc
index 8f34baa7de..c296daa95d 100644
--- a/tensorflow/core/lib/strings/numbers.cc
+++ b/tensorflow/core/lib/strings/numbers.cc
@@ -33,19 +33,26 @@ namespace tensorflow {
 
 namespace {
 
+template <typename T>
+const std::unordered_map<string, T>* GetSpecialNumsSingleton() {
+  static const std::unordered_map<string, T>* special_nums =
+      CHECK_NOTNULL((new const std::unordered_map<string, T>{
+          {"inf", std::numeric_limits<T>::infinity()},
+          {"+inf", std::numeric_limits<T>::infinity()},
+          {"-inf", -std::numeric_limits<T>::infinity()},
+          {"infinity", std::numeric_limits<T>::infinity()},
+          {"+infinity", std::numeric_limits<T>::infinity()},
+          {"-infinity", -std::numeric_limits<T>::infinity()},
+          {"nan", std::numeric_limits<T>::quiet_NaN()},
+          {"+nan", std::numeric_limits<T>::quiet_NaN()},
+          {"-nan", -std::numeric_limits<T>::quiet_NaN()},
+      }));
+  return special_nums;
+}
+
 template <typename T>
 T locale_independent_strtonum(const char* str, const char** endptr) {
-  static const std::unordered_map<string, T> special_nums = {
-      {"inf", std::numeric_limits<T>::infinity()},
-      {"+inf", std::numeric_limits<T>::infinity()},
-      {"-inf", -std::numeric_limits<T>::infinity()},
-      {"infinity", std::numeric_limits<T>::infinity()},
-      {"+infinity", std::numeric_limits<T>::infinity()},
-      {"-infinity", -std::numeric_limits<T>::infinity()},
-      {"nan", std::numeric_limits<T>::quiet_NaN()},
-      {"+nan", std::numeric_limits<T>::quiet_NaN()},
-      {"-nan", -std::numeric_limits<T>::quiet_NaN()},
-  };
+  auto special_nums = GetSpecialNumsSingleton<T>();
   std::stringstream s(str);
 
   // Check if str is one of the special numbers.
@@ -57,8 +64,8 @@ T locale_independent_strtonum(const char* str, const char** endptr) {
         std::tolower(special_num_str[i], std::locale::classic());
   }
 
-  auto entry = special_nums.find(special_num_str);
-  if (entry != special_nums.end()) {
+  auto entry = special_nums->find(special_num_str);
+  if (entry != special_nums->end()) {
     *endptr = str + (s.eof() ? static_cast<std::iostream::pos_type>(strlen(str))
                              : s.tellg());
     return entry->second;
-- 
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