diff --git a/c11logtest/c11logtest/c11logtest.vcxproj b/c11logtest/c11logtest/c11logtest.vcxproj
index a28d09cf..c827e71e 100644
--- a/c11logtest/c11logtest/c11logtest.vcxproj
+++ b/c11logtest/c11logtest/c11logtest.vcxproj
@@ -84,7 +84,7 @@
     <Text Include="ReadMe.txt" />
   </ItemGroup>
   <ItemGroup>
-    <ClInclude Include="..\..\include\c11log\common_types.h" />
+    <ClInclude Include="..\..\include\c11log\common.h" />
     <ClInclude Include="..\..\include\c11log\details\blocking_queue.h" />
     <ClInclude Include="..\..\include\c11log\details\factory.h" />
     <ClInclude Include="..\..\include\c11log\details\fast_oss.h" />
diff --git a/c11logtest/c11logtest/c11logtest.vcxproj.filters b/c11logtest/c11logtest/c11logtest.vcxproj.filters
index 9ee71f3d..4b803831 100644
--- a/c11logtest/c11logtest/c11logtest.vcxproj.filters
+++ b/c11logtest/c11logtest/c11logtest.vcxproj.filters
@@ -33,9 +33,6 @@
     <ClInclude Include="targetver.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\c11log\common_types.h">
-      <Filter>Header Files\c11log</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\c11log\formatter.h">
       <Filter>Header Files\c11log</Filter>
     </ClInclude>
@@ -90,6 +87,9 @@
     <ClInclude Include="..\..\include\c11log\sinks\stdout_sinks.h">
       <Filter>Header Files\c11log\sinks</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\c11log\common.h">
+      <Filter>Header Files\c11log</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">
diff --git a/example/example.cpp b/example/example.cpp
index 6401c5d7..b17e4873 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -20,14 +20,14 @@ int main(int argc, char* argv[])
 
     const unsigned int howmany = argc <= 1 ? 10000 : atoi(argv[1]);
 
-    logger cout_logger("example", std::make_shared<sinks::stderr_sink_st>());
+    logger cout_logger("example", std::make_shared<sinks::stderr_sink_mt>());
     cout_logger.info() << "Hello logger";
 
     //auto nullsink = std::make_shared<sinks::null_sink<std::mutex>>();
-    //auto nullsink = std::make_shared<sinks::null_sink<details::null_mutex>>();
-    auto fsink = std::make_shared<sinks::rotating_file_sink_mt>("log", "txt", 1024*1024*50 , 5, 1);
-    //auto as = std::make_shared<sinks::async_sink>(1000);
-    //as->add_sink(fsink);
+    auto nullsink = std::make_shared<sinks::null_sink<details::null_mutex>>();
+    auto fsink = std::make_shared<sinks::rotating_file_sink_st>("log", "txt", 1024*1024*50 , 5, 10);
+    auto as = std::make_shared<sinks::async_sink>(1000);
+
 
     logger my_logger("my_logger", fsink);
 
@@ -36,7 +36,7 @@ int main(int argc, char* argv[])
     for (unsigned int i = 1; i <= howmany; ++i)
         my_logger.info() << "Hello logger: msg #" << i;
 
-    //as->shutdown(std::chrono::milliseconds(15000));
+
     auto delta = system_clock::now() - start;
     auto delta_d = duration_cast<duration<double>> (delta).count();
 
diff --git a/include/c11log/common_types.h b/include/c11log/common_types.h
deleted file mode 100644
index 527996bd..00000000
--- a/include/c11log/common_types.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#pragma once
-
-#include <chrono>
-
-namespace c11log
-{
-
-typedef std::chrono::system_clock log_clock;
-
-namespace level
-{
-typedef enum
-{
-    TRACE,
-    DEBUG,
-    INFO,
-    WARNING,
-    ERROR,
-    CRITICAL,
-    FATAL,
-    NONE = 99
-} level_enum;
-
-static const char* level_names[] { "trace", "debug", "info", "warning", "error", "critical", "fatal" };
-inline const char* to_str(c11log::level::level_enum l)
-{
-    return level_names[l];
-}
-} //level
-} //c11log
diff --git a/include/c11log/details/line_logger.h b/include/c11log/details/line_logger.h
index f0a53885..9c866b55 100644
--- a/include/c11log/details/line_logger.h
+++ b/include/c11log/details/line_logger.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #include <sstream>
-#include "../common_types.h"
+#include "../common.h"
 #include "../logger.h"
 #include "fast_oss.h"
 
diff --git a/include/c11log/details/log_msg.h b/include/c11log/details/log_msg.h
index bed7f414..b8920a0f 100644
--- a/include/c11log/details/log_msg.h
+++ b/include/c11log/details/log_msg.h
@@ -1,6 +1,7 @@
 #pragma once
 
-#include "../common_types.h"
+#include <chrono>
+#include "../common.h"
 
 namespace c11log
 {
@@ -16,7 +17,6 @@ struct log_msg
         raw(),
         formatted() {}
 
-
     log_msg(const log_msg& other):
         logger_name(other.logger_name),
         level(other.level),
diff --git a/include/c11log/formatter.h b/include/c11log/formatter.h
index 955d7237..ae77201a 100644
--- a/include/c11log/formatter.h
+++ b/include/c11log/formatter.h
@@ -8,7 +8,7 @@
 #include <cstring>
 #include <sstream>
 
-#include "common_types.h"
+#include "common.h"
 #include "details/os.h"
 #include "details/log_msg.h"
 #include "details/fast_oss.h"
diff --git a/include/c11log/logger.h b/include/c11log/logger.h
index ac0179a9..1b70866c 100644
--- a/include/c11log/logger.h
+++ b/include/c11log/logger.h
@@ -8,8 +8,7 @@
 #include <sstream>
 
 #include "sinks/base_sink.h"
-#include "common_types.h"
-
+#include "common.h"
 
 
 
diff --git a/include/c11log/sinks/async_sink.h b/include/c11log/sinks/async_sink.h
index cedb31ee..9648fc0d 100644
--- a/include/c11log/sinks/async_sink.h
+++ b/include/c11log/sinks/async_sink.h
@@ -8,6 +8,7 @@
 #include "base_sink.h"
 #include "../logger.h"
 #include "../details/blocking_queue.h"
+#include "../details/null_mutex.h"
 #include "../details/log_msg.h"
 
 #include<iostream>
@@ -17,8 +18,7 @@ namespace c11log
 namespace sinks
 {
 
-template<class Mutex>
-class async_sink : public base_sink<Mutex>
+class async_sink : public base_sink<details::null_mutex>
 {
 public:
     using q_type = details::blocking_queue<details::log_msg>;
@@ -26,7 +26,6 @@ public:
     explicit async_sink(const q_type::size_type max_queue_size);
 
     //Stop logging and join the back thread
-    // TODO: limit with timeout of the join and kill it afterwards?
     ~async_sink();
     void add_sink(logger::sink_ptr sink);
     void remove_sink(logger::sink_ptr sink_ptr);
@@ -46,7 +45,7 @@ private:
     std::thread _back_thread;
     //Clear all remaining messages(if any), stop the _back_thread and join it
     void _shutdown();
-    std::mutex _shutdown_mutex;
+    std::mutex _mutex;
 };
 }
 }
@@ -54,30 +53,26 @@ private:
 ///////////////////////////////////////////////////////////////////////////////
 // async_sink class implementation
 ///////////////////////////////////////////////////////////////////////////////
-template<class Mutex>
-inline c11log::sinks::async_sink<Mutex>::async_sink(const q_type::size_type max_queue_size)
+inline c11log::sinks::async_sink::async_sink(const q_type::size_type max_queue_size)
     :_sinks(),
      _active(true),
      _q(max_queue_size),
      _back_thread(&async_sink::_thread_loop, this)
 {}
 
-template<class Mutex>
-inline c11log::sinks::async_sink<Mutex>::~async_sink()
+inline c11log::sinks::async_sink::~async_sink()
 {
     _shutdown();
 }
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::_sink_it(const details::log_msg& msg)
+inline void c11log::sinks::async_sink::_sink_it(const details::log_msg& msg)
 {
     if(!_active || msg.formatted.empty())
         return;
     _q.push(msg);
 }
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::_thread_loop()
+inline void c11log::sinks::async_sink::_thread_loop()
 {
     static std::chrono::seconds  pop_timeout { 1 };
     while (_active)
@@ -95,27 +90,27 @@ inline void c11log::sinks::async_sink<Mutex>::_thread_loop()
     }
 }
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::add_sink(logger::sink_ptr sink)
+inline void c11log::sinks::async_sink::add_sink(logger::sink_ptr sink)
 {
+    std::lock_guard<std::mutex> guard(_mutex);
     _sinks.push_back(sink);
 }
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::remove_sink(logger::sink_ptr sink)
+
+inline void c11log::sinks::async_sink::remove_sink(logger::sink_ptr sink)
 {
+    std::lock_guard<std::mutex> guard(_mutex);
     _sinks.erase(std::remove(_sinks.begin(), _sinks.end(), sink), _sinks.end());
 }
-/*
-template<class Mutex>
-inline c11log::sinks::async_sink::q_type& c11log::sinks::async_sink<Mutex>::q()
+
+
+inline c11log::sinks::async_sink::q_type& c11log::sinks::async_sink::q()
 {
     return _q;
-}*/
+}
 
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::shutdown(const std::chrono::milliseconds& timeout)
+inline void c11log::sinks::async_sink::shutdown(const std::chrono::milliseconds& timeout)
 {
     if(timeout > std::chrono::milliseconds::zero())
     {
@@ -129,10 +124,9 @@ inline void c11log::sinks::async_sink<Mutex>::shutdown(const std::chrono::millis
 }
 
 
-template<class Mutex>
-inline void c11log::sinks::async_sink<Mutex>::_shutdown()
+inline void c11log::sinks::async_sink::_shutdown()
 {
-    std::lock_guard<std::mutex> guard(_shutdown_mutex);
+    std::lock_guard<std::mutex> guard(_mutex);
     if(_active)
     {
         _active = false;
diff --git a/include/c11log/sinks/base_sink.h b/include/c11log/sinks/base_sink.h
index f880bc23..4b583ddb 100644
--- a/include/c11log/sinks/base_sink.h
+++ b/include/c11log/sinks/base_sink.h
@@ -5,7 +5,7 @@
 #include<atomic>
 #include "isink.h"
 #include "../formatter.h"
-#include "../common_types.h"
+#include "../common.h"
 #include "../details/log_msg.h"
 
 
@@ -23,7 +23,7 @@ public:
     base_sink(const base_sink&) = delete;
     base_sink& operator=(const base_sink&) = delete;
 
-    void log(const details::log_msg& msg)
+    void log(const details::log_msg& msg) override
     {
         if (_enabled)
         {
@@ -32,12 +32,12 @@ public:
         }
     };
 
-    void enable(bool enabled)
+    void enable(bool enabled) override
     {
         _enabled = enabled;
     }
 
-    bool is_enabled()
+    bool is_enabled() override
     {
         return _enabled.load();
     }
@@ -48,8 +48,5 @@ protected:
     std::atomic<bool> _enabled;
 
 };
-
-
-
 }
 }
diff --git a/include/c11log/sinks/file_sinks.h b/include/c11log/sinks/file_sinks.h
index bcbb55bc..9eade65c 100644
--- a/include/c11log/sinks/file_sinks.h
+++ b/include/c11log/sinks/file_sinks.h
@@ -87,12 +87,10 @@ private:
     }
 
 
-    // Rotate old files:
+    // Rotate files:
     // log.txt -> log.1.txt
-    // log.n-1.txt -> log.n.txt
-    // log.n-2.txt -> log.n-1.txt
-    // log.n-3.txt ->..
-    // log.n.txt -> log.txt
+    // ..
+    // log.n.txt -> log.n+1.txt
 
 
     void _rotate()
diff --git a/include/c11log/sinks/ostream_sink.h b/include/c11log/sinks/ostream_sink.h
index 9f603d69..507e343b 100644
--- a/include/c11log/sinks/ostream_sink.h
+++ b/include/c11log/sinks/ostream_sink.h
@@ -26,7 +26,6 @@ protected:
     {
         _ostream << msg.formatted;
     }
-
     std::ostream& _ostream;
 };