补上遗漏的TestSharedMutexBenchmark.cpp文件

Change-Id: I2129b6dc44dc4a5ce70001e2d878642bd740981a

Chapter03/code/TestSharedMutexBenchmark.cpp

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+/**
+ * std::shared_mutex与std::mutex的性能对比
+ * zhangyl 2016.11.10
+ */
+
+ //读线程数量
+#define READER_THREAD_COUNT  8
+//最大循环次数
+#define LOOP_COUNT           5000000
+
+#include <iostream>
+#include <mutex>  
+#include <shared_mutex>
+#include <thread>
+
+class shared_mutex_counter
+{
+public:
+	shared_mutex_counter() = default;
+	~shared_mutex_counter() = default;
+
+	//使用std::shared_mutex，同一时刻多个读线程可以同时访问value_值
+	unsigned int get() const
+	{
+		//注意：这里使用std::shared_lock
+		std::shared_lock<std::shared_mutex> lock(mutex_);
+		return value_;
+	}
+
+	//使用std::shared_mutex，同一个时刻仅有一个写线程可以修改value_值
+	void increment()
+	{
+		//注意：这里使用std::unique_lock
+		std::unique_lock<std::shared_mutex> lock(mutex_);
+		value_++;
+	}
+
+	//使用std::shared_mutex，同一个时刻仅有一个写线程可以重置value_值
+	void reset()
+	{
+		//注意：这里使用std::unique_lock
+		std::unique_lock<std::shared_mutex> lock(mutex_);
+		value_ = 0;
+	}
+
+private:
+	mutable std::shared_mutex   mutex_;
+	//value_是多个线程的共享资源
+	unsigned int                value_ = 0;
+};
+
+class mutex_counter
+{
+public:
+	mutex_counter() = default;
+	~mutex_counter() = default;
+
+	//使用std::mutex，同一时刻仅有一个线程可以访问value_的值
+	unsigned int get() const
+	{
+		std::unique_lock<std::mutex> lk(mutex_);
+		return value_;
+	}
+
+	//使用std::mutex，同一时刻仅有一个线程可以修改value_的值
+	void increment()
+	{
+		std::unique_lock<std::mutex> lk(mutex_);
+		value_++;
+	}
+
+private:
+	mutable std::mutex      mutex_;
+	//value_是多个线程的共享资源
+	unsigned int            value_ = 0;
+};
+
+//测试std::shared_mutex
+void test_shared_mutex()
+{
+	shared_mutex_counter counter;
+	int temp;
+
+	//写线程函数
+	auto writer = [&counter]() {
+		for (int i = 0; i < LOOP_COUNT; i++)
+		{
+			counter.increment();
+		}
+	};
+
+	//读线程函数
+	auto reader = [&counter, &temp]() {
+		for (int i = 0; i < LOOP_COUNT; i++)
+		{
+			temp = counter.get();
+		}
+	};
+
+	//存放读线程对象指针的数组
+	std::thread** tarray = new std::thread * [READER_THREAD_COUNT];
+
+	//记录起始时间
+	clock_t start = clock();
+
+	//创建READER_THREAD_COUNT个读线程
+	for (int i = 0; i < READER_THREAD_COUNT; i++)
+	{
+		tarray[i] = new std::thread(reader);
+	}
+
+	//创建一个写线程
+	std::thread tw(writer);
+
+	for (int i = 0; i < READER_THREAD_COUNT; i++)
+	{
+		tarray[i]->join();
+	}
+	tw.join();
+
+	//记录起始时间
+	clock_t end = clock();
+	printf("[test_shared_mutex]\n");
+	printf("thread count: %d\n", READER_THREAD_COUNT);
+	printf("result: %d cost: %dms temp: %d \n", counter.get(), end - start, temp);
+}
+
+//测试std::mutex
+void test_mutex()
+{
+	mutex_counter counter;
+
+	int temp;
+
+	//写线程函数
+	auto writer = [&counter]() {
+		for (int i = 0; i < LOOP_COUNT; i++)
+		{
+			counter.increment();
+		}
+	};
+
+	//读线程函数
+	auto reader = [&counter, &temp]() {
+		for (int i = 0; i < LOOP_COUNT; i++)
+		{
+			temp = counter.get();
+		}
+	};
+
+	//存放读线程对象指针的数组
+	std::thread** tarray = new std::thread * [READER_THREAD_COUNT];
+
+	//记录起始时间
+	clock_t start = clock();
+
+	//创建READER_THREAD_COUNT个读线程
+	for (int i = 0; i < READER_THREAD_COUNT; i++)
+	{
+		tarray[i] = new std::thread(reader);
+	}
+
+	//创建一个写线程
+	std::thread tw(writer);
+
+	for (int i = 0; i < READER_THREAD_COUNT; i++)
+	{
+		tarray[i]->join();
+	}
+	tw.join();
+
+	//记录结束时间
+	clock_t end = clock();
+	printf("[test_mutex]\n");
+	printf("thread count:%d\n", READER_THREAD_COUNT);
+	printf("result:%d cost:%dms temp:%d \n", counter.get(), end - start, temp);
+}
+
+int main()
+{
+	//为了排除测试程序的无关因素，测试时只开启一个  
+	test_mutex();
+	//test_shared_mutex();
+	return 0;
+}