1 http://blog.163.com/xychenbaihu@yeah/blog/static/1322296552013373236132/
2
3 https://www.cnblogs.com/wzjhoutai/p/6838104.html
4
5
6
7
8
9 #include<stdio.h>
10 #include<string.h>
11 #include<stdlib.h>
12 #include<pthread.h>
13
14 int count = 0;
15 void *func_cas(void*arg)
16 {
17 int i=0;
18 int temp = 0;
19
20 for(i = 0;i < 20000;i++)
21 {
22 while(1)
23 {
24 temp = count;
25 if(__sync_bool_compare_and_swap(&count, temp, temp+1))
26 break;
27 }
28
29 }
30 }
31
32 void *func(void*arg)
33 {
34 int i=0;
35
36 for(i = 0;i < 20000;i++)
37 {
38 count++;
39 }
40 }
41
42
43 int main()
44 {
45 pthread_t id[10];
46 int i=0;
47 for(i=0 ;i< sizeof(id)/sizeof(id[0]);i++)
48 {
49 pthread_create(&id[i],NULL,func_cas,NULL);
50 }
51
52 for(i=0 ;i< sizeof(id)/sizeof(id[0]);i++)
53 {
54 pthread_join(id[i],NULL);
55 }
56
57 printf("count = %d\n",count);
58
59 count = 0;
60
61 for(i=0 ;i< sizeof(id)/sizeof(id[0]);i++)
62 {
63 pthread_create(&id[i],NULL,func,NULL);
64 }
65
66 for(i=0 ;i< sizeof(id)/sizeof(id[0]);i++)
67 {
68 pthread_join(id[i],NULL);
69 }
70 printf("\ncount = %d\n",count);
71 }
72
73
74
