From fe20eb715e781fcfe758641d2973d68cfe1c561f Mon Sep 17 00:00:00 2001
From: selim <selim@fastmail.fm>
Date: Sun, 14 Sep 2014 09:03:40 +0400
Subject: [PATCH] =?UTF-8?q?=D0=94=D0=BE=D0=B1=D0=B0=D0=B2=D0=BB=D0=B5?=
 =?UTF-8?q?=D0=BD=20=D0=B1=D0=B0=D0=B7=D0=BE=D0=B2=D1=8B=D0=B9=20=D0=B2?=
 =?UTF-8?q?=D0=B0=D1=80=D0=B8=D0=B0=D0=BD=D1=82=20=D0=BF=D1=83=D0=BB=D0=B0?=
 =?UTF-8?q?=20=D0=BF=D0=BE=D1=82=D0=BE=D0=BA=D0=BE=D0=B2?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 include/threadpool.h                 | 41 +++++++++++++++++++++++++++
 msvc/cpputil/cpputil.vcxproj         |  2 ++
 msvc/cpputil/cpputil.vcxproj.filters |  6 ++++
 src/threadpool.cpp                   | 42 ++++++++++++++++++++++++++++
 4 files changed, 91 insertions(+)
 create mode 100644 include/threadpool.h
 create mode 100644 src/threadpool.cpp

diff --git a/include/threadpool.h b/include/threadpool.h
new file mode 100644
index 0000000..0645885
--- /dev/null
+++ b/include/threadpool.h
@@ -0,0 +1,41 @@
+#ifndef _THREADPOOL_H_
+#define _THREADPOOL_H_
+
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+#include <functional>
+#include <queue>
+#include <vector>
+#include <future>
+
+class threadpool
+{
+private:
+	std::size_t _concurrency;
+	std::queue<std::function<void()>> _queue;
+	std::mutex _mutex;
+	std::condition_variable _cv;
+	std::vector<std::thread> _workers;
+	bool _enabled;
+
+public:
+	threadpool();
+	threadpool(std::size_t concurrency);
+	~threadpool();
+
+	template <typename R> std::future<R> add_task(std::function<R()> func)
+	{
+		std::lock_guard<std::mutex> lock(_mutex);
+		std::packaged_task<R()> pt(func);
+		std::future<R> fut = pt.get_future();
+		_queue.push([&pt]{ pt(); });
+		_cv.notify_all();
+		return fut;
+	}
+
+private:
+	void worker_func();
+};
+
+#endif // _THREADPOOL_H_
diff --git a/msvc/cpputil/cpputil.vcxproj b/msvc/cpputil/cpputil.vcxproj
index bcf3baa..40070fc 100644
--- a/msvc/cpputil/cpputil.vcxproj
+++ b/msvc/cpputil/cpputil.vcxproj
@@ -78,12 +78,14 @@
   <ItemGroup>
     <ClCompile Include="..\..\src\logger.cpp" />
     <ClCompile Include="..\..\src\log_queue.cpp" />
+    <ClCompile Include="..\..\src\threadpool.cpp" />
     <ClCompile Include="..\..\src\ustring.cpp" />
     <ClCompile Include="..\..\src\utf.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\include\logger.h" />
     <ClInclude Include="..\..\include\log_queue.h" />
+    <ClInclude Include="..\..\include\threadpool.h" />
     <ClInclude Include="..\..\include\ustring.h" />
     <ClInclude Include="..\..\include\utf.h" />
   </ItemGroup>
diff --git a/msvc/cpputil/cpputil.vcxproj.filters b/msvc/cpputil/cpputil.vcxproj.filters
index 23af821..e94e4e2 100644
--- a/msvc/cpputil/cpputil.vcxproj.filters
+++ b/msvc/cpputil/cpputil.vcxproj.filters
@@ -30,6 +30,9 @@
     <ClCompile Include="..\..\src\utf.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\threadpool.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\include\log_queue.h">
@@ -44,5 +47,8 @@
     <ClInclude Include="..\..\include\utf.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\threadpool.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/threadpool.cpp b/src/threadpool.cpp
new file mode 100644
index 0000000..f58cb22
--- /dev/null
+++ b/src/threadpool.cpp
@@ -0,0 +1,42 @@
+#include "threadpool.h"
+
+threadpool::threadpool() : threadpool(std::thread::hardware_concurrency())
+{
+}
+
+threadpool::threadpool(std::size_t concurrency) : _concurrency(concurrency), _enabled(true)
+{
+	for (std::size_t i = 0; i < _concurrency; ++i)
+	{
+		_workers.push_back(std::thread(&threadpool::worker_func, this));
+	}
+}
+
+threadpool::~threadpool()
+{
+	_enabled = false;
+	_cv.notify_all();
+	for (std::size_t i = 0; i < _workers.size(); ++i)
+	{
+		_workers[i].join();
+	}
+}
+
+void threadpool::worker_func()
+{
+	while (_enabled)
+	{
+		std::unique_lock<std::mutex> lock(_mutex);
+		_cv.wait(lock, [this] { return (!_queue.empty() || !_enabled); });
+
+		if (_queue.empty() && !_enabled)
+			return;
+
+		auto func = _queue.front();
+		_queue.pop();
+
+		lock.unlock();
+
+		func();
+	}
+}