feat(c++/multi-thread-programming): add lock queue/stack examples

c++/multi-thread-programming/ex24_lock_queue.cpp

@@ -0,0 +1,90 @@
+#include <iostream>
+#include <atomic>
+#include <queue>
+#include <mutex>
+#include <future>
+#include <thread>
+
+using namespace std;
+
+#define OUT
+
+template<typename T>
+class LockQueue
+{
+public:
+	LockQueue() { }
+
+	// 복사하지 못하도록 막음
+	LockQueue(const LockQueue&) = delete;
+	LockQueue& operator=(const LockQueue&) = delete;
+
+	void Push(T value)
+	{
+		lock_guard<mutex> lock(_mutex);
+		_queue.push(std::move(value));
+
+		_condVar.notify_one();
+	}
+
+	bool TryPop(T& value)
+	{
+		lock_guard<mutex> lock(_mutex);
+		if (_queue.empty())
+			return false;
+
+		value = std::move(_queue.front());
+		_queue.pop();
+		return true;
+	}
+
+	void WaitPop(T& value)
+	{
+		unique_lock<mutex> lock(_mutex);
+		_condVar.wait(lock, [this] { return _queue.empty() == false; });
+
+		value = std::move(_queue.front());
+		_queue.pop();
+	}
+
+private:
+	queue<T> _queue;
+	mutex _mutex;
+	condition_variable _condVar;
+};
+
+LockQueue<int> q;
+
+void Push()
+{
+	while (true)
+	{
+		int value = rand() % 100;
+		q.Push(value);
+
+		this_thread::sleep_for(chrono::milliseconds(10));
+	}
+}
+
+void Pop()
+{
+	while (true)
+	{
+		int data = 0;
+		if (q.TryPop(OUT data))
+			cout << data << endl;
+		// q.WaitPop(OUT data);
+		// cout << data << endl;
+	}
+}
+
+int main()
+{
+	thread t1(Push);
+	thread t2(Pop);
+	thread t3(Pop);
+
+	t1.join();
+	t2.join();
+	t3.join();
+}

c++/multi-thread-programming/ex24_lock_stack.cpp

@@ -0,0 +1,92 @@
+#include <iostream>
+#include <atomic>
+#include <stack>
+#include <mutex>
+#include <future>
+#include <thread>
+
+using namespace std;
+
+#define OUT
+
+template<typename T>
+class LockStack
+{
+public:
+	LockStack() { }
+
+	// 복사하지 못하도록 막음
+	LockStack(const LockStack&) = delete;
+	LockStack& operator=(const LockStack&) = delete;
+
+	void Push(T value)
+	{
+		lock_guard<mutex> lock(_mutex);
+		_stack.push(std::move(value));
+
+		_condVar.notify_one();
+	}
+
+	bool TryPop(T& value)
+	{
+		lock_guard<mutex> lock(_mutex);
+		// NOTE: Empty 함수 호출 후 Pop을 호출하는 구조가 아니라, 락을 잡고 Empty인지 체크 + Pop 시도까지 함께 진행.
+		if (_stack.empty())
+			return false;
+
+		value = std::move(_stack.top());
+		_stack.pop();
+		return true;
+	}
+
+	void WaitPop(T& value)
+	{
+		unique_lock<mutex> lock(_mutex);
+		// 비어있지 않은 경우(empty == false) 통과. 비어있는 동안에는 쓰레드를 대기 상태로 전환.
+		_condVar.wait(lock, [this] { return _stack.empty() == false; });
+
+		value = std::move(_stack.top());
+		_stack.pop();
+	}
+
+private:
+	stack<T> _stack;
+	mutex _mutex;
+	condition_variable _condVar;
+};
+
+LockStack<int> s;
+
+void Push()
+{
+	while (true)
+	{
+		int value = rand() % 100;
+		s.Push(value);
+
+		this_thread::sleep_for(chrono::milliseconds(10));
+	}
+}
+
+void Pop()
+{
+	while (true)
+	{
+		int data = 0;
+		if (s.TryPop(OUT data))
+			cout << data << endl;
+		// s.WaitPop(OUT data);
+		// cout << data << endl;
+	}
+}
+
+int main()
+{
+	thread t1(Push);
+	thread t2(Pop);
+	thread t3(Pop);
+
+	t1.join();
+	t2.join();
+	t3.join();
+}