全局變量,多線程操作不安全,可能會導致結果不安全

互斥鎖,操作很慢,但是結果正確

原子變量,操作很快,結果正確

代碼示例

 1 #include <Windows.h>
 2 #include <thread>
 3 #include <iostream>
 4 #include <tuple>
 5 using namespace std;
 6 
 7 void run()
 8 {
 9     MessageBox(0, L"hello", L"hello", 0);
10 }
11 
12 void runA(const wchar_t *s, const
 
 wchar_t *b)
13 {
14     MessageBox(0, s, b, 0);
15 }
16 
17 class myclass
18 {
19 public:
20     void operator()()//C++重載
21     {
22         MessageBox(0, L"hello", L"hello", 0);
23     }
24 };
25 
26 void main1()
27 {
28     thread t1[3]{ thread(run),thread(run),thread(run) };
29 
30     thread *p1 = new
 
 thread(run);
31     thread *p2 = new thread(run);
32 
33     thread *p(new thread[3]{ thread(run),thread(run),thread(run) });
34     //偽函數
35     thread t3[3]{ thread(myclass()),thread(myclass()) ,thread(myclass()) };
36     system("pause");
37 }
38 
39 void main()
40 {
41     //多線程帶參數
42     thread t1(runA, L"
 
木頭人1", L"HELLO");
43     thread t2(runA, L"木頭人1", L"HELLO");
44     thread t3(runA, L"木頭人1", L"HELLO");
45 
46     //tuple數組
47     char ch = ‘X‘;
48     short sh = 129;
49     int num = 1234;
50     char *p = "木頭人";
51     tuple<char, short, int, char *>mytuple(ch, sh, num, p);
52     auto i0 = get<0>(mytuple);
53     cout << i0 << endl;
54     auto i1 = get<1>(mytuple);
55     cout << i1 << endl;
56     auto i2 = get<2>(mytuple);
57     cout << i2 << endl;
58     auto i3 = get<3>(mytuple);
59     cout << i3 << endl;
60     cin.get();
61 }

3.原子變量