thread usage

Signed-off-by: ericyuanhui <ericxu890302@gmail.com>

Author: ericyuanhui

Language/C_plus/thread/thread.cpp

@@ -0,0 +1,144 @@
+//g++ thread.cpp -pthread/-lpthread -std=c++11
+
+#include <iostream>       // std::cout
+#include <thread>         // std::thread, std::this_thread::sleep_for
+#include <chrono>         // std::chrono::seconds
+#include <array>
+#include <mutex>
+#include <atomic>
+
+using namespace std;
+
+const int N = 1000000000;
+int num = 0;
+mutex m;
+atomic_int ato_num{0};
+
+void run() {
+    for(int i=0; i<N; i++) {
+        /*m.lock();
+        num++;
+        m.unlock();*/
+        //ato_num++;
+        num++;
+    }
+}
+
+void pause_thread(int n) {
+    std::this_thread::sleep_for (std::chrono::seconds(n));
+    std::cout << "pause of " << n << " seconds ended\n";
+}
+
+void show(const char *str, const int id) {
+    std::cout << "thread=" << id+1 << " : " << str << std::endl;
+}
+
+void print() {
+    cout << "hello test!" << endl;
+}
+
+void fun1(int n)  //初始化构造函数
+{
+	cout << "Thread " << n << " executing\n";
+	n += 10;
+	this_thread::sleep_for(chrono::milliseconds(10));
+}
+
+void fun2(int & n) //拷贝构造函数
+{
+	cout << "Thread " << n << " executing\n";
+	n += 20;
+	this_thread::sleep_for(chrono::milliseconds(10));
+}
+
+int main() {
+    // join thread
+    std::cout << "Spawning 3 threads...\n";
+    std::thread t3(pause_thread, 3);
+    std::thread t1(pause_thread, 1);
+    std::thread t2(pause_thread, 2);
+    std::cout << "Done spawning threads. Now waiting for them to join:\n";
+    t1.join();
+    t2.join();
+    t3.join();
+    std::cout << "All threads joined!\n";
+    // thread detach
+    std::cout << "Spawning and detaching 3 threads...\n";
+    std::thread t4(pause_thread, 3);
+    std::thread t5(pause_thread, 1);
+    std::thread t6(pause_thread, 2);
+    t4.detach();
+    t5.detach();
+    t6.detach();
+    std::cout << "Done spawning threads.\n";
+
+    std::cout << "(the main thread will now pause for 5 seconds)\n";
+    //give the detached threads time to finish (but not guaranteed!):
+    pause_thread(5);
+
+    // thread joinable usage
+    std::cout << "thread joinable usage \n";
+    std::thread t;
+    std::cout << "before starting joinable: " << t.joinable() << "\n";
+    t = std::thread(pause_thread, 5);
+    std::cout << "after starting, joinable: " << t.joinable() << "\n";
+    t.join();
+    std::cout << "after join, joinable: " << t.joinable() << "\n";
+
+    // swap thread
+    std::thread t7(pause_thread, 10);
+    std::thread::id t7_id = t7.get_id();
+
+    std::thread t8(pause_thread, 20);
+    std::thread::id t8_id = t8.get_id();
+
+    std::cout << "t7 id: " << t7_id << "\n";
+    std::cout << "t8 id: " << t8_id << "\n";
+
+    swap(t7, t8);
+
+    std::cout << "t7 id: " << t7.get_id() << "\n";
+    std::cout << "t8 id: " << t8.get_id() << "\n";
+
+    t7.join();
+    t8.join();
+
+    // thread different thread input
+    int n = 0;
+    thread t11;               //t11不是一个thread
+    thread t12(fun1, n + 1);  //按照值传递
+    t12.join();
+    cout << "n=" << n << '\n';
+    n = 10;
+    thread t13(fun2, ref(n)); //引用
+    thread t14(move(t13));     //t14执行t13，t13不是thread
+    t14.join();
+    cout << "n=" << n << '\n';
+
+    array<thread, 3> thread_array = {thread(print), thread(print), thread(print)};
+    for(int i=0; i<3; i++) {
+        cout << thread_array[i].joinable() << endl;
+        thread_array[i].join();
+    }
+
+    //thread cpu number
+    auto cpu = thread::hardware_concurrency();
+    cout << "thread cpu num " << cpu << endl;
+
+    // mutex usage
+    clock_t start = clock();
+    thread t15(run);
+    //thread t16(run);
+    t15.join();
+    thread t16(run);
+    t16.join();
+    clock_t end = clock();
+    cout << "num = " << num << " time = " << end-start << " ms" << endl;
+    //cout << "ato num = " << ato_num << " time = " << end-start << " ms" << endl;
+
+
+
+    return 0;
+}
+
+