摘自：https://www.cnblogs.com/zhoug2020/p/3951352.html

pthread_getpecific和pthread_setspecific实现同一个线程中不同函数间共享数据的一种很好的方式。

 

 1 /*
 2 
 3  * =====================================================================================
 4 
 5  *       Filename:  thead.c
 6 
 7  *    Description:  getspecific
 8 
 9  *        Created:  05/10/2011 12:09:43 AM
10 
11  * =====================================================================================
12 
13  */
14 
15 #include<stdio.h>
16 
17 #include<pthread.h>
18 
19 #include<string.h>
20 
21 pthread_key_t p_key;
22 
23  
24 
25 void func1()
26 
27 {
28 
29         int *tmp = (int*)pthread_getspecific(p_key);//同一线程内的各个函数间共享数据。
30 
31         printf("%d is runing in %s\n",*tmp,__func__);
32 
33  
34 
35 }
36 
37 void *thread_func(void *args)
38 
39 {
40 
41  
42 
43         pthread_setspecific(p_key,args);
44 
45  
46 
47         int *tmp = (int*)pthread_getspecific(p_key);//获得线程的私有空间
48 
49         printf("%d is runing in %s\n",*tmp,__func__);
50 
51  
52 
53         *tmp = (*tmp)*100;//修改私有变量的值
54 
55  
56 
57         func1();
58 
59  
60 
61         return (void*)0;
62 
63 }
64 
65 int main()
66 
67 {
68 
69         pthread_t pa, pb;
70 
71         int a=1;
72 
73         int b=2;
74 
75         pthread_key_create(&p_key,NULL);
76 
77         pthread_create(&pa, NULL,thread_func,&a);
78 
79         pthread_create(&pb, NULL,thread_func,&b);
80 
81         pthread_join(pa, NULL);
82 
83         pthread_join(pb, NULL);
84 
85         return 0;
86 
87 }
88 
89  

#gcc -lpthread  test.c -o test
# ./test 

2 is runing in thread_func
1 is runing in thread_func
100 is runing in func1
200 is runing in func1