diff --git a/c11log.sln b/c11log.sln
new file mode 100644
index 00000000..582ead83
--- /dev/null
+++ b/c11log.sln
@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2013
+VisualStudioVersion = 12.0.21005.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "c11log", "c11log.vcxproj", "{BBFA8622-1945-4EB0-BAF4-473BE753ED24}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "test", "test\test.vcxproj", "{429A1E1E-6F89-4941-B4A7-7464CEA22587}"
+	ProjectSection(ProjectDependencies) = postProject
+		{BBFA8622-1945-4EB0-BAF4-473BE753ED24} = {BBFA8622-1945-4EB0-BAF4-473BE753ED24}
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Win32 = Debug|Win32
+		Release|Win32 = Release|Win32
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{BBFA8622-1945-4EB0-BAF4-473BE753ED24}.Debug|Win32.ActiveCfg = Debug|Win32
+		{BBFA8622-1945-4EB0-BAF4-473BE753ED24}.Debug|Win32.Build.0 = Debug|Win32
+		{BBFA8622-1945-4EB0-BAF4-473BE753ED24}.Release|Win32.ActiveCfg = Release|Win32
+		{BBFA8622-1945-4EB0-BAF4-473BE753ED24}.Release|Win32.Build.0 = Release|Win32
+		{429A1E1E-6F89-4941-B4A7-7464CEA22587}.Debug|Win32.ActiveCfg = Debug|Win32
+		{429A1E1E-6F89-4941-B4A7-7464CEA22587}.Debug|Win32.Build.0 = Debug|Win32
+		{429A1E1E-6F89-4941-B4A7-7464CEA22587}.Release|Win32.ActiveCfg = Release|Win32
+		{429A1E1E-6F89-4941-B4A7-7464CEA22587}.Release|Win32.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/c11log.v12.suo b/c11log.v12.suo
new file mode 100644
index 00000000..da81938b
Binary files /dev/null and b/c11log.v12.suo differ
diff --git a/include/c11log/details/blocking_queue.h b/include/c11log/details/blocking_queue.h
index 0859b98b..4a9cbb15 100644
--- a/include/c11log/details/blocking_queue.h
+++ b/include/c11log/details/blocking_queue.h
@@ -21,17 +21,16 @@ public:
     using size_type = typename queue_t::size_type;
     using clock = std::chrono::system_clock;
 
-    explicit blocking_queue(size_type max_size) :_max_size(max_size), _q()
+    explicit blocking_queue(size_type max_size) :max_size_(max_size), q_()
     {}
     blocking_queue(const blocking_queue&) = delete;
-    blocking_queue& operator=(const blocking_queue&) = delete;
-    blocking_queue& operator=(const blocking_queue&) volatile = delete;
+    blocking_queue& operator=(const blocking_queue&) = delete;    
     ~blocking_queue() = default;
 
     size_type size()
     {
-        std::lock_guard<std::mutex> lock(_mutex);
-        return _q.size();
+        std::lock_guard<std::mutex> lock(mutex_);
+        return q_.size();
     }
 
     // Push copy of item into the back of the queue. 
@@ -40,17 +39,17 @@ public:
     template<class Duration_Rep, class Duration_Period>
     bool push(const T& item, const std::chrono::duration<Duration_Rep, Duration_Period>& timeout)
     {
-        std::unique_lock<std::mutex> ul(_mutex);
-        if (_q.size() >= _max_size)
+        std::unique_lock<std::mutex> ul(mutex_);
+        if (q_.size() >= max_size_)
         {
-            if (!_item_popped_cond.wait_until(ul, clock::now() + timeout, [this]() { return this->_q.size() < this->_max_size; }))
+            if (!item_popped_cond_.wait_until(ul, clock::now() + timeout, [this]() { return this->q_.size() < this->max_size_; }))
                 return false;
         }
-        _q.push(item);
-        if (_q.size() <= 1)
+        q_.push(item);
+        if (q_.size() <= 1)
         {
             ul.unlock(); //So the notified thread will have better chance to accuire the lock immediatly..
-            _item_pushed_cond.notify_one();
+            item_pushed_cond_.notify_one();
         }
         return true;
     }
@@ -68,18 +67,18 @@ public:
     template<class Duration_Rep, class Duration_Period>
     bool pop(T& item, const std::chrono::duration<Duration_Rep, Duration_Period>& timeout)
     {
-        std::unique_lock<std::mutex> ul(_mutex);
-        if (_q.empty())
+        std::unique_lock<std::mutex> ul(mutex_);
+        if (q_.empty())
         {
-            if (!_item_pushed_cond.wait_until(ul, clock::now() + timeout, [this]() { return !this->_q.empty(); }))
+            if (!item_pushed_cond_.wait_until(ul, clock::now() + timeout, [this]() { return !this->q_.empty(); }))
                 return false;
         }
-        item = _q.front();
-        _q.pop();
-        if (_q.size() >= _max_size - 1)
+        item = q_.front();
+        q_.pop();
+        if (q_.size() >= max_size_ - 1)
         {
             ul.unlock(); //So the notified thread will have better chance to accuire the lock immediatly..
-            _item_popped_cond.notify_one();
+            item_popped_cond_.notify_one();
         }
         return true;
     }
@@ -91,12 +90,19 @@ public:
         while (!pop(item, std::chrono::hours::max()));
     }
 
+    // Clear the queue
+    void clear()
+    {
+        T item;
+        while (pop(item, std::chrono::milliseconds(0)));        
+    }
+
 private:
-    size_type _max_size;
-    std::queue<T> _q;
-    std::mutex _mutex;
-    std::condition_variable _item_pushed_cond;
-    std::condition_variable _item_popped_cond;
+    size_type max_size_;
+    std::queue<T> q_;
+    std::mutex mutex_;
+    std::condition_variable item_pushed_cond_;
+    std::condition_variable item_popped_cond_;
 };
 }
 }
\ No newline at end of file
diff --git a/include/c11log/logger.h b/include/c11log/logger.h
index 3105d82a..0ca87398 100644
--- a/include/c11log/logger.h
+++ b/include/c11log/logger.h
@@ -1,5 +1,7 @@
 #pragma once
 
+// Thread safe logger
+// Has log level and vector sinks which do the actual logging
 #include<vector>
 #include<memory>
 #include<mutex>
@@ -20,15 +22,13 @@ public:
     typedef std::shared_ptr<sinks::base_sink>  sink_ptr_t;
     typedef std::vector<sink_ptr_t> sinks_vector_t;
 
-    explicit logger(const std::string& name) : _logger_name(name),
-        _formatter(std::make_unique<formatters::default_formatter>())
+    explicit logger(const std::string& name) : logger_name_(name),
+        formatter_(std::make_unique<formatters::default_formatter>())
     {
-        _atomic_level.store(level::INFO);
+        atomic_level_.store(level::INFO);
     }
 
-    ~logger()
-    {
-    };
+    ~logger() = default;
 
     logger(const logger&) = delete;
     logger& operator=(const logger&) = delete;
@@ -53,30 +53,32 @@ private:
     friend details::line_logger;
 
 
-    std::string _logger_name = "";
-    std::unique_ptr<c11log::formatters::formatter> _formatter;
-    sinks_vector_t _sinks;
-    std::mutex _mutex;
-    std::atomic_int _atomic_level;
+    std::string logger_name_ = "";
+    std::unique_ptr<c11log::formatters::formatter> formatter_;
+    sinks_vector_t sinks_;
+    std::mutex mutex_;
+    std::atomic_int atomic_level_;
 
-    void _log_it(const std::string& msg);
+    void log_it_(const std::string& msg);
 
 };
 
 logger& get_logger(const std::string& name);
 }
 
-/*
-Logger inline impl
-*/
-
+//
+// Logger inline impl
+//
 inline c11log::details::line_logger c11log::logger::log(c11log::level::level_enum msg_level)
 {
 
-    if (msg_level >= _atomic_level.load()) {
-        std::lock_guard<std::mutex> lock(_mutex);
+    if (msg_level >= atomic_level_.load())
+    {
+        std::lock_guard<std::mutex> lock(mutex_);
         return details::line_logger(this, msg_level);
-    } else {
+    } 
+    else
+    {
         return details::line_logger(nullptr);
     }
 
@@ -105,56 +107,57 @@ inline c11log::details::line_logger c11log::logger::fatal()
 
 inline void c11log::logger::set_name(const std::string& name)
 {
-    std::lock_guard<std::mutex> lock(_mutex);
-    _logger_name = name;
+    std::lock_guard<std::mutex> lock(mutex_);
+    logger_name_ = name;
 }
 
 inline const std::string& c11log::logger::get_name()
 {
-    std::lock_guard<std::mutex> lock(_mutex);
-    return _logger_name;
+    std::lock_guard<std::mutex> lock(mutex_);
+    return logger_name_;
 }
 
 inline void c11log::logger::add_sink(sink_ptr_t sink_ptr)
 {
-    std::lock_guard<std::mutex> lock(_mutex);
-    _sinks.push_back(sink_ptr);
+    std::lock_guard<std::mutex> lock(mutex_);
+    sinks_.push_back(sink_ptr);
 }
 
 inline void c11log::logger::remove_sink(sink_ptr_t sink_ptr)
 {
-    std::lock_guard<std::mutex> lock(_mutex);
-    _sinks.erase(std::remove(_sinks.begin(), _sinks.end(), sink_ptr), _sinks.end());
+    std::lock_guard<std::mutex> lock(mutex_);
+    sinks_.erase(std::remove(sinks_.begin(), sinks_.end(), sink_ptr), sinks_.end());
 }
 
 inline void c11log::logger::set_formatter(std::unique_ptr<formatters::formatter> formatter)
 {
-    std::lock_guard<std::mutex> lock(_mutex);
-    _formatter = std::move(formatter);
+    std::lock_guard<std::mutex> lock(mutex_);
+    formatter_ = std::move(formatter);
 }
 
 inline void c11log::logger::set_level(c11log::level::level_enum level)
 {
-    _atomic_level.store(level);
+    atomic_level_.store(level);
 }
 
 inline c11log::level::level_enum c11log::logger::get_level() const
 {
-    return static_cast<c11log::level::level_enum>(_atomic_level.load());
+    return static_cast<c11log::level::level_enum>(atomic_level_.load());
 }
 
 inline bool c11log::logger::should_log(c11log::level::level_enum level) const
 {
-    return level >= _atomic_level.load();
+    return level >= atomic_level_.load();
 }
-inline void c11log::logger::_log_it(const std::string& msg)
+inline void c11log::logger::log_it_(const std::string& msg)
 {
-    level::level_enum level = static_cast<level::level_enum>(_atomic_level.load());
-    std::lock_guard<std::mutex> lock(_mutex);
-    for (auto &sink : _sinks)
+    level::level_enum level = static_cast<level::level_enum>(atomic_level_.load());
+    std::lock_guard<std::mutex> lock(mutex_);
+    for (auto &sink : sinks_)
         sink->log(msg, level);
 }
 
+// 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 8f95c6c5..5d9a9138 100644
--- a/include/c11log/sinks/async_sink.h
+++ b/include/c11log/sinks/async_sink.h
@@ -1,55 +1,98 @@
 #pragma once
-#include <mutex>
-#include <queue>
-#include <thread>
-#include <iostream>
 
-#include "../logger.h"
+#include <thread>
+#include <chrono>
+#include <mutex>
+#include <atomic>
+
 #include "base_sink.h"
+#include "../logger.h"
+#include "../details/blocking_queue.h"
+
 namespace c11log {
 namespace sinks {
-class async_sink : base_sink {
-    enum class fullq_policy {
-        BLOCK=0,
-        DROP_MSG
-    };
+class async_sink : public base_sink {
+    
 public:
-    async_sink(std::size_t max_queue_size, fullq_policy q_policy) :_fullq_policy(q_policy), _back_thread(&_thread_loop)
-    {
-
-    }
-protected:
-    void _sink_it(const std::string& msg) override
-    {
-        _msgs_mutex.unlock();
-        _msgs.push(msg);
-    }
-    void _thread_loop()
-    {
-        while (_active) {
-            _msgs_mutex.lock();
-            std::string &msg = _msgs.front();
-            _msgs.pop();
-            _msgs_mutex.unlock();
-            std::cout << "Popped: " << msg << std::endl;
-        }
-    }
-
-private:
-    c11log::logger::sinks_vector_t _sinks;
-    fullq_policy _fullq_policy;
-    std::queue<std::string> _msgs;
-    std::thread _back_thread;
-    bool _active = true;
-    std::mutex _msgs_mutex;
-
-
+    using size_type = c11log::details::blocking_queue<std::string>::size_type;    
+    explicit async_sink(const std::size_t max_queue_size, const std::chrono::seconds& timeout = std::chrono::seconds::max());        
+    ~async_sink();
+    void add_sink(logger::sink_ptr_t sink);
+    void remove_sink(logger::sink_ptr_t sink_ptr);    
+    
 
+protected:    
+    void sink_it_(const std::string& msg) override;
+    void thread_loop_();
+    
+private:    
+    c11log::logger::sinks_vector_t sinks_;
+    bool active_ = true;    
+    const std::chrono::seconds timeout_;
+    c11log::details::blocking_queue<std::string> q_;
+    std::thread back_thread_; 
+    void shutdown_();
 };
 }
 }
 
-void c11log::sinks::async_sink::_sink_it(const std::string& msg)
-{
+//
+// async_sink inline impl
+//
+
+inline c11log::sinks::async_sink::async_sink(const std::size_t max_queue_size, const std::chrono::seconds& timeout)
+    :q_(max_queue_size),
+    timeout_(timeout),
+    back_thread_(&async_sink::thread_loop_, this)
+{}
+
+inline c11log::sinks::async_sink::~async_sink()
+{
+    shutdown_();
+}
+inline void c11log::sinks::async_sink::sink_it_(const std::string& msg)
+{
+    q_.push(msg, timeout_);
+}
+
+inline void c11log::sinks::async_sink::thread_loop_()
+{   
+    std::string msg;
+    while (active_) 
+    {        
+        if (q_.pop(msg, timeout_))
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            for (auto &sink : sinks_)
+            {
+                if (active_)
+                    sink->log(msg, _level);
+                else
+                    break;
+            }
+        }
+    }
+}
+
+inline void c11log::sinks::async_sink::add_sink(logger::sink_ptr_t sink)
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    sinks_.push_back(sink);
+}
+
+inline void c11log::sinks::async_sink::remove_sink(logger::sink_ptr_t sink_ptr)
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    sinks_.erase(std::remove(sinks_.begin(), sinks_.end(), sink_ptr), sinks_.end());
+}
+
+inline void c11log::sinks::async_sink::shutdown_()
+{
+    {        
+        std::lock_guard<std::mutex> lock(mutex_);
+        active_ = false;        
+    }
+    q_.clear();
+    back_thread_.join();
+}
 
-}
\ No newline at end of file
diff --git a/include/c11log/sinks/base_sink.h b/include/c11log/sinks/base_sink.h
index 87349972..bf444729 100644
--- a/include/c11log/sinks/base_sink.h
+++ b/include/c11log/sinks/base_sink.h
@@ -1,4 +1,5 @@
 #pragma once
+
 #include<string>
 #include<memory>
 #include<mutex>
@@ -10,40 +11,38 @@ namespace c11log {
 namespace sinks {
 class base_sink {
 public:
-    base_sink()
-    {}
+    base_sink() = default;    
     base_sink(level::level_enum l):_level(l)
     {};
-    virtual ~base_sink()
-    {};
-
+    virtual ~base_sink() = default;
+    
     base_sink(const base_sink&) = delete;
     base_sink& operator=(const base_sink&) = delete;
 
     void log(const std::string &msg, level::level_enum level)
     {
         if (level >= _level) {
-            std::lock_guard<std::mutex> lock(_mutex);
+            std::lock_guard<std::mutex> lock(mutex_);
             if (level >= _level)
-                _sink_it(msg);
+                sink_it_(msg);
         }
     };
 
     void set_level(level::level_enum level)
     {
-        std::lock_guard<std::mutex> lock(_mutex);
+        std::lock_guard<std::mutex> lock(mutex_);
         _level = level;
     }
 
 protected:
-    virtual void _sink_it(const std::string& msg) = 0;
+    virtual void sink_it_(const std::string& msg) = 0;
     level::level_enum _level = level::INFO;
-    std::mutex _mutex;
+    std::mutex mutex_;
 };
 
 class null_sink:public base_sink {
 protected:
-    void _sink_it(const std::string& msg) override
+    void sink_it_(const std::string& msg) override
     {}
 };
 }
diff --git a/include/c11log/sinks/file_sinks.h b/include/c11log/sinks/file_sinks.h
index bd729c42..a8edf5c0 100644
--- a/include/c11log/sinks/file_sinks.h
+++ b/include/c11log/sinks/file_sinks.h
@@ -1,4 +1,5 @@
 #pragma once
+
 #include <fstream>
 #include  <iomanip>
 
@@ -22,7 +23,7 @@ public:
         _ofstream.open(oss.str(), std::ofstream::app);
     }
 protected:
-    void _sink_it(const std::string& msg) override
+    void sink_it_(const std::string& msg) override
     {
         _ofstream << msg;
         _ofstream.flush();
@@ -43,7 +44,7 @@ public:
     virtual ~rotating_file_sink_base()
     {}
 protected:
-    virtual void _sink_it(const std::string& msg) override
+    virtual void sink_it_(const std::string& msg) override
     {
         if (_should_rotate())
             _rotate();
@@ -69,10 +70,10 @@ public:
     }
 
 protected:
-    virtual void _sink_it(const std::string& msg) override
+    virtual void sink_it_(const std::string& msg) override
     {
         _current_size += msg.length();
-        rotating_file_sink_base::_sink_it(msg);
+        rotating_file_sink_base::sink_it_(msg);
     }
 
     bool _should_rotate() const override
diff --git a/include/c11log/sinks/stdout_sinks.h b/include/c11log/sinks/stdout_sinks.h
index 8f6b3e37..1ec0d7c5 100644
--- a/include/c11log/sinks/stdout_sinks.h
+++ b/include/c11log/sinks/stdout_sinks.h
@@ -1,41 +1,38 @@
+#pragma once
 
 #include <iostream>
 #include "base_sink.h"
 
 namespace c11log
 {
-	namespace sinks
+namespace sinks
+{
+class ostream_sink: public base_sink
+{
+public:
+	ostream_sink(std::ostream& os):_ostream(os) {}
+    virtual ~ostream_sink() = default;
+
+protected:
+	virtual void sink_it_(const std::string& msg) override
 	{
-		class ostream_sink:public base_sink
-		{
-		public:
-			ostream_sink(std::ostream& os):_ostream(os)
-			{}
-
-			virtual ~ostream_sink()
-			{}
-
-		protected:
-			virtual void _sink_it(const std::string& msg)
-			{
-				_ostream << msg;
-			}
-			std::ostream& _ostream;
-
-		};
-
-		class stdout_sink:public ostream_sink
-		{
-		public:
-			stdout_sink():ostream_sink(std::cout)
-			{}
-		};
-
-		class stderr_sink:public ostream_sink
-		{
-		public:
-			stderr_sink():ostream_sink(std::cerr)
-			{}
-		};
+		_ostream << msg;
 	}
+
+	std::ostream& _ostream;
+};
+
+class stdout_sink:public ostream_sink
+{
+public:
+    stdout_sink():ostream_sink(std::cout) {}
+};
+
+class stderr_sink:public ostream_sink
+{
+public:
+    stderr_sink():ostream_sink(std::cerr) {}
+	
+};
+}
 }
\ No newline at end of file
diff --git a/src/line_logger.cpp b/src/line_logger.cpp
index f1b984ec..77c8708c 100644
--- a/src/line_logger.cpp
+++ b/src/line_logger.cpp
@@ -5,7 +5,7 @@ c11log::details::line_logger::line_logger(logger* callback_logger, level::level_
     _callback_logger(callback_logger)
 {
     if (callback_logger) {
-        callback_logger->_formatter->format_header(callback_logger->_logger_name,
+        callback_logger->formatter_->format_header(callback_logger->logger_name_,
                 msg_level,
                 c11log::formatters::timepoint::clock::now(),
                 _oss);
@@ -16,6 +16,6 @@ c11log::details::line_logger::~line_logger()
 {
     if (_callback_logger) {
         _oss << '\n';
-        _callback_logger->_log_it(_oss.str_ref());
+        _callback_logger->log_it_(_oss.str_ref());
     }
 }
\ No newline at end of file
diff --git a/test/stdafx.cpp b/test/stdafx.cpp
new file mode 100644
index 00000000..ab6cf716
--- /dev/null
+++ b/test/stdafx.cpp
@@ -0,0 +1,8 @@
+// stdafx.cpp : source file that includes just the standard includes
+// test.pch will be the pre-compiled header
+// stdafx.obj will contain the pre-compiled type information
+
+#include "stdafx.h"
+
+// TODO: reference any additional headers you need in STDAFX.H
+// and not in this file
diff --git a/test/stdafx.h b/test/stdafx.h
new file mode 100644
index 00000000..da4e7055
--- /dev/null
+++ b/test/stdafx.h
@@ -0,0 +1,16 @@
+// stdafx.h : include file for standard system include files,
+// or project specific include files that are used frequently, but
+// are changed infrequently
+//
+
+#pragma once
+
+#include <thread>
+#include <iostream>
+#include <chrono>
+
+#include "utils.h"
+#include "../include/c11log/logger.h"
+#include "../include/c11log/sinks/async_sink.h"
+#include "../include/c11log/sinks/stdout_sinks.h"
+#include "../include/c11log/sinks/file_sinks.h"
diff --git a/test/test.cpp b/test/test.cpp
new file mode 100644
index 00000000..d6ec4839
--- /dev/null
+++ b/test/test.cpp
@@ -0,0 +1,24 @@
+// test.cpp : Defines the entry point for the console application.
+//
+
+#include "stdafx.h"
+
+
+void fn();
+int main(int argc, char* argv[])
+{
+
+    c11log::logger logger("test");
+
+    auto sink = std::make_shared<c11log::sinks::stdout_sink>();
+    auto async = std::make_shared<c11log::sinks::async_sink>(100);
+    async->add_sink(sink);
+    logger.add_sink(async);
+    logger.info() << "Hello logger!";
+    utils::run(std::chrono::seconds(10), fn);
+    return 0;
+}
+
+static void fn()
+{}
+
diff --git a/test/utils.h b/test/utils.h
new file mode 100644
index 00000000..c9b56b18
--- /dev/null
+++ b/test/utils.h
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <functional>
+#include <chrono>
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <locale>
+
+namespace utils
+{
+
+template<typename T>
+std::string format(const T& value)
+{
+    static std::locale loc("");
+    std::stringstream ss;
+    ss.imbue(loc);
+    ss << value;
+    return ss.str();
+}
+
+inline void run(const std::chrono::milliseconds &duration, const std::function<void() >& fn)
+{
+    using namespace std::chrono;
+    typedef steady_clock the_clock;
+    size_t counter = 0;
+    seconds print_interval(1);
+    auto start_time = the_clock::now();
+    auto lastPrintTime = start_time;
+    while (true)
+    {
+        fn();
+        ++counter;
+        auto now = the_clock::now();
+        if (now - start_time >= duration)
+            break;
+        auto p = now - lastPrintTime;
+        if (now - lastPrintTime >= print_interval)
+        {
+            std::cout << format(counter) << " per sec" << std::endl;
+            counter = 0;
+            lastPrintTime = the_clock::now();
+        }
+    }
+}
+}
\ No newline at end of file