diff --git a/example/example.cpp b/example/example.cpp
index c06d5a6d..462613a1 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -2,7 +2,7 @@
 //
 
 #include "c11log/logger.h"
-//#include "c11log/sinks/async_sink.h"
+#include "c11log/sinks/async_sink.h"
 #include "c11log/sinks/file_sinks.h"
 #include "c11log/sinks/console_sinks.h"
 
@@ -19,14 +19,12 @@ int main(int argc, char* argv[])
 {
 
     if(argc || argv) {};
-    const unsigned int howmany = 5000000;
+    const unsigned int howmany = argc <= 1 ? 1500000 :atoi(argv[1]);
 
     auto fsink = std::make_shared<sinks::rotating_file_sink>("log", "txt", 1024*1024*50 , 5, 0);
-    //auto fsink = std::make_shared<sinks::simple_file_sink>("simplelog", "txt");
     auto null_sink = std::make_shared<sinks::null_sink>();
 
-    logger cout_logger ("cout", {null_sink, sinks::stdout_sink()});
-
+    logger cout_logger ("cout", {sinks::stdout_sink()});
     cout_logger.info() << "Hello cout logger!";
 
     logger my_logger ("my_logger", {null_sink});
@@ -36,9 +34,8 @@ int main(int argc, char* argv[])
     auto start = system_clock::now();
     for(unsigned int i = 0; i < howmany ; i++)
         my_logger.info() << s;
-    //my_logger.info() << "Hello logger " << i;;
 
-    //async->shutdown(seconds(3));
+
     auto delta = system_clock::now() - start;
     auto delta_d = duration_cast<duration<double>> (delta).count();
     cout_logger.info() << "Total " << format(howmany);
diff --git a/include/c11log/common_types.h b/include/c11log/common_types.h
index 85ea8ba0..d4b1efea 100644
--- a/include/c11log/common_types.h
+++ b/include/c11log/common_types.h
@@ -25,14 +25,5 @@ inline const char* to_str(c11log::level::level_enum l)
 {
     return level_names[l];
 }
-}
-
-struct log_msg
-{
-	bufpair_t msg_buf;
-    log_clock::time_point msg_time;
-    std::size_t msg_header_size;
-    level::level_enum msg_level;
-};
-
-}
+} //level
+} //c11log
diff --git a/include/c11log/details/line_logger.h b/include/c11log/details/line_logger.h
index 04fadec4..fce5a933 100644
--- a/include/c11log/details/line_logger.h
+++ b/include/c11log/details/line_logger.h
@@ -72,7 +72,7 @@ public:
 
 private:
     logger* _callback_logger;
-    c11log::log_msg _log_msg;
+    log_msg _log_msg;
     details::stack_oss _oss;
     bool _enabled;
 
diff --git a/include/c11log/details/os.h b/include/c11log/details/os.h
index ab91284c..0e66950a 100644
--- a/include/c11log/details/os.h
+++ b/include/c11log/details/os.h
@@ -28,9 +28,6 @@ inline std::tm localtime()
     return localtime(now_t);
 }
 
-
-
-
 inline bool operator==(const std::tm& tm1, const std::tm& tm2)
 {
     return (tm1.tm_sec == tm2.tm_sec &&
diff --git a/include/c11log/details/stack_buf.h b/include/c11log/details/stack_buf.h
index f0774fb5..01d9d4f2 100644
--- a/include/c11log/details/stack_buf.h
+++ b/include/c11log/details/stack_buf.h
@@ -3,7 +3,7 @@
 #include <array>
 #include <vector>
 #include <algorithm>
-
+#include <cstring>
 
 // Fast memory storage
 // stores its contents on the stack when possible, in vector<char> otherwise
diff --git a/include/c11log/logger.h b/include/c11log/logger.h
index 4b303823..97b124b0 100644
--- a/include/c11log/logger.h
+++ b/include/c11log/logger.h
@@ -68,7 +68,7 @@ private:
     sinks_vector_t _sinks;
     std::atomic_int _logger_level;
 
-    void _log_it(const log_msg& msg);
+    void _log_it(const details::log_msg& msg);
 
 };
 
@@ -146,14 +146,13 @@ inline bool c11log::logger::should_log(c11log::level::level_enum level) const
     return level >= _logger_level.load();
 }
 
-inline void c11log::logger::_log_it(const log_msg& msg)
+inline void c11log::logger::_log_it(const details::log_msg& msg)
 {
     for (auto &sink : _sinks)
         sink->log(msg);
 }
 
 // Static factory function
-
 inline c11log::logger& c11log::get_logger(const std::string& name)
 {
     return *(c11log::details::factory::instance().get_logger(name));
diff --git a/include/c11log/sinks/async_sink.h b/include/c11log/sinks/async_sink.h
index 4eba5b2b..fb92733b 100644
--- a/include/c11log/sinks/async_sink.h
+++ b/include/c11log/sinks/async_sink.h
@@ -7,7 +7,10 @@
 #include "base_sink.h"
 #include "../logger.h"
 #include "../details/blocking_queue.h"
+#include "../details/log_msg.h"
 
+
+using namespace std;
 namespace c11log
 {
 namespace sinks
@@ -16,7 +19,9 @@ namespace sinks
 class async_sink : public base_sink
 {
 public:
-    using size_type = c11log::details::blocking_queue<std::string>::size_type;
+
+    using queue_t = c11log::details::blocking_queue<std::shared_ptr<details::log_msg>>;
+    using size_type = queue_t::size_type;
 
     explicit async_sink(const size_type max_queue_size);
     ~async_sink();
@@ -28,13 +33,13 @@ public:
 
 
 protected:
-    void _sink_it(const bufpair_t& msg) override;
+    void _sink_it(const details::log_msg& msg) override;
     void _thread_loop();
 
 private:
     c11log::logger::sinks_vector_t _sinks;
     std::atomic<bool> _active;
-    c11log::details::blocking_queue<std::string> _q;
+    queue_t _q;
     std::thread _back_thread;
     //Clear all remaining messages(if any), stop the _back_thread and join it
     void _shutdown();
@@ -46,7 +51,7 @@ private:
 // async_sink class implementation
 ///////////////////////////////////////////////////////////////////////////////
 
-inline c11log::sinks::async_sink::async_sink(const std::size_t max_queue_size)
+inline c11log::sinks::async_sink::async_sink(const size_type max_queue_size)
     :_sinks(),
      _active(true),
      _q(max_queue_size),
@@ -57,27 +62,33 @@ inline c11log::sinks::async_sink::~async_sink()
 {
     _shutdown();
 }
-inline void c11log::sinks::async_sink::_sink_it(const bufpair_t& msg)
+inline void c11log::sinks::async_sink::_sink_it(const details::log_msg& msg)
 {
-    std::string s {msg.first, msg.first+msg.second};
-    _q.push(s);
+    //re allocate on the heap the (stack based) message
+    auto new_msg = new details::log_msg();
+    *new_msg = msg;
+    auto msg_size = msg.msg_buf.second;
+    char *buf = new char[msg_size];
+    std::memcpy(buf, msg.msg_buf.first, msg_size);
+    new_msg->msg_buf = bufpair_t(buf, msg_size);
+    auto new_shared = std::shared_ptr<details::log_msg>(new_msg, [](details::log_msg* msg_to_delete)
+    {
+        delete []msg_to_delete->msg_buf.first;
+    });
+    _q.push(new_shared);
 }
 
 inline void c11log::sinks::async_sink::_thread_loop()
 {
     static std::chrono::seconds  pop_timeout { 1 };
-    std::string msg;
-
     while (_active)
     {
+        std::shared_ptr<details::log_msg> msg;
         if (_q.pop(msg, pop_timeout))
         {
-            bufpair_t buf(msg.data(), msg.size());
             for (auto &sink : _sinks)
             {
-                sink->log(buf, level::INFO);
-                if (!_active)
-                    return;
+                sink->log(*msg);
             }
         }
     }
diff --git a/include/c11log/sinks/base_sink.h b/include/c11log/sinks/base_sink.h
index b5e4a93d..b2a6b9f0 100644
--- a/include/c11log/sinks/base_sink.h
+++ b/include/c11log/sinks/base_sink.h
@@ -5,6 +5,7 @@
 
 #include "../formatter.h"
 #include "../common_types.h"
+#include "../details/log_msg.h"
 
 namespace c11log
 {
@@ -19,7 +20,7 @@ public:
     base_sink(const base_sink&) = delete;
     base_sink& operator=(const base_sink&) = delete;
 
-    void log(const log_msg& msg)
+    void log(const details::log_msg& msg)
     {
         if (_enabled)
         {
@@ -38,14 +39,14 @@ public:
     }
 
 protected:
-    virtual void _sink_it(const log_msg& msg) = 0;
+    virtual void _sink_it(const details::log_msg& msg) = 0;
     std::atomic<bool> _enabled;
 };
 
 class null_sink:public base_sink
 {
 protected:
-    void _sink_it(const log_msg&) override
+    void _sink_it(const details::log_msg&) override
     {
     }
 };
diff --git a/include/c11log/sinks/console_sinks.h b/include/c11log/sinks/console_sinks.h
index a8a45af8..86830207 100644
--- a/include/c11log/sinks/console_sinks.h
+++ b/include/c11log/sinks/console_sinks.h
@@ -19,7 +19,7 @@ public:
     virtual ~console_sink() = default;
 
 protected:
-    virtual void _sink_it(const log_msg& msg) override
+    virtual void _sink_it(const details::log_msg& msg) override
     {
         std::lock_guard<std::mutex> lock(_mutex);
         _ostream.write(msg.msg_buf.first, msg.msg_buf.second);
diff --git a/include/c11log/sinks/file_sinks.h b/include/c11log/sinks/file_sinks.h
index 1d227fb5..0b345321 100644
--- a/include/c11log/sinks/file_sinks.h
+++ b/include/c11log/sinks/file_sinks.h
@@ -6,6 +6,7 @@
 #include <mutex>
 #include "base_sink.h"
 #include "../details/flush_helper.h"
+#include "../details/blocking_queue.h"
 
 namespace c11log
 {
@@ -27,7 +28,7 @@ public:
     {
     }
 protected:
-    void _sink_it(const log_msg& msg) override
+    void _sink_it(const details::log_msg& msg) override
     {
         std::lock_guard<std::mutex> lock(_mutex);
         _flush_helper.write(msg.msg_buf, _ofstream);
@@ -60,7 +61,7 @@ public:
     }
 
 protected:
-    void _sink_it(const log_msg& msg) override
+    void _sink_it(const details::log_msg& msg) override
     {
         std::lock_guard<std::mutex> lock(_mutex);
 
@@ -134,7 +135,7 @@ public:
     }
 
 protected:
-    void _sink_it(const log_msg& msg) override
+    void _sink_it(const details::log_msg& msg) override
     {
         std::lock_guard<std::mutex> lock(_mutex);
         if (std::chrono::system_clock::now() >= _midnight_tp)