fix for non-threadsafe use of localtime fixes #347

changelog.md

@@ -32,6 +32,7 @@ HEAD
   header. Thank you Max Dmitrichenko for reporting and a patch.
 - Bug: use of `std::put_time` is now guarded by a general 11 flag rather than
   a chrono flag. Thank you Max Dmitrichenko for reporting.
+- Bug: Fixes non-thread safe use of std::localtime. #347 #383
 - Compatibility: Adjust usage of std::min to be more compatible with systems
   that define a min(...) macro.
 - Compatibility: Removes unused parameters from all library, test, and example

websocketpp/common/time.hpp

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2014, Peter Thorson. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the WebSocket++ Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef WEBSOCKETPP_COMMON_TIME_HPP
+#define WEBSOCKETPP_COMMON_TIME_HPP
+
+#include <time.h>
+
+namespace websocketpp {
+namespace lib {
+
+// Code in this header was inspired by the following article and includes some
+// code from the related project g2log. The g2log code is public domain licensed
+// http://kjellkod.wordpress.com/2013/01/22/exploring-c11-part-2-localtime-and-time-again/
+
+/// Thread safe cross platform localtime
+inline std::tm localtime(std::time_t const & time) {
+    std::tm tm_snapshot;
+#if (defined(WIN32) || defined(_WIN32) || defined(__WIN32__))
+    localtime_s(&tm_snapshot, &time); 
+#else
+    localtime_r(&time, &tm_snapshot); // POSIX  
+#endif
+    return tm_snapshot;
+}
+
+} // lib
+} // websocketpp
+
+#endif // WEBSOCKETPP_COMMON_TIME_HPP

websocketpp/logger/basic.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Peter Thorson. All rights reserved.
+ * Copyright (c) 2014, Peter Thorson. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -46,6 +46,7 @@
 
 #include <websocketpp/common/cpp11.hpp>
 #include <websocketpp/common/stdint.hpp>
+#include <websocketpp/common/time.hpp>
 #include <websocketpp/logger/levels.hpp>
 
 namespace websocketpp {
@@ -132,13 +133,13 @@ private:
     // TODO: find a workaround for this or make this format user settable
     static std::ostream & timestamp(std::ostream & os) {
         std::time_t t = std::time(NULL);
-        std::tm* lt = std::localtime(&t);
-            return os << std::put_time(lt,"%Y-%m-%d %H:%M:%S");
+        std::tm lt = lib::localtime(t);
         #ifdef _WEBSOCKETPP_PUTTIME_
+            return os << std::put_time(&lt,"%Y-%m-%d %H:%M:%S");
         #else // Falls back to strftime, which requires a temporary copy of the string.
             char buffer[20];
-            std::strftime(buffer,sizeof(buffer),"%Y-%m-%d %H:%M:%S",lt);
-            return os << buffer;
+            size_t result = std::strftime(buffer,sizeof(buffer),"%Y-%m-%d %H:%M:%S",&lt);
+            return os << (result == 0 ? "Unknown" : buffer);
         #endif
     }