Merge pull request #92 from JacobMao/master

fixed a bug which is cased by no threadsafe.

Author: JosephP91

include/curl_exception.h

@@ -32,6 +32,7 @@
 #include <utility>
 #include <vector>
 #include <algorithm>
+#include <mutex>
 #include <curl/curl.h>
 
 #include "curl_config.h"
@@ -74,6 +75,11 @@ namespace curl {
          * when an exception is thrown.
          */
         static curlcpp_traceback traceback;
+        
+        /**
+         * Locker for inserting traceback.
+         */
+         static std::mutex tracebackLocker;
     };
 
     // Implementation of print_traceback

src/curl_exception.cpp

@@ -11,9 +11,15 @@ using curl::curlcpp_traceback;
 // Need to define the traceback here to separate declaration from definition, or we'll get a linker error.
 curlcpp_traceback curl::curl_exception::traceback;
 
+std::mutex curl::curl_exception::tracebackLocker;
+
 // Constructor implementation. Every call will push into the calls stack the function name and the error occurred.
 curl_exception::curl_exception(const std::string &error, const std::string &fun_name) {
+    curl_exception::tracebackLocker.lock();
+
     curl_exception::traceback.insert(curl_exception::traceback.begin(),curlcpp_traceback_object(error,fun_name));
+
+    curl_exception::tracebackLocker.unlock();
 }
 
 // Implementation of destructor.