From a56f70c340d4e5a88ba0800ad4115e53c5495e88 Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Sun, 2 Sep 2018 15:44:19 +0300
Subject: [PATCH] Safer init_openssl_threads.

GitOrigin-RevId: ecb7a2dbcf48aae55e611e7f95d0a1f0c4a8413d
---
 tdutils/td/utils/crypto.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tdutils/td/utils/crypto.cpp b/tdutils/td/utils/crypto.cpp
index edad176a..d7fe1815 100644
--- a/tdutils/td/utils/crypto.cpp
+++ b/tdutils/td/utils/crypto.cpp
@@ -32,6 +32,7 @@
 
 #include <algorithm>
 #include <cstring>
+#include <mutex>
 #include <utility>
 
 namespace td {
@@ -611,6 +612,8 @@ void openssl_locking_function(int mode, int n, const char *file, int line) {
 
 void init_openssl_threads() {
 #if OPENSSL_VERSION_NUMBER < 0x10100000L
+  static std::mutex init_mutex;
+  std::lock_guard<std::mutex> lock(init_mutex);
   if (CRYPTO_get_locking_callback() == nullptr) {
 #if OPENSSL_VERSION_NUMBER >= 0x10000000L
     CRYPTO_THREADID_set_callback(openssl_threadid_callback);