先看执行的结果：
1 主函数正在创建线程，... 2 线程1被创建 3 Thread1 : I'm thread 1th 4 线程2被创建 5 Thread2 : I'm thread 2nd 6 thread2 : number = 0 7 线程3被创建 8 主函数正在等待线程结束... 9 thread1 : number = 0 10 Thread3 : I'm thread 3nd 11 thread3 : number = 2 12 thread3 : number = 3 13 thread2 : number = 4 14 thread1 : number = 5 15 thread3 : number = 6 16 thread2 : number = 7 17 thread3 : number = 8 18 thread1 : number = 9 19 thread3 : number = 10 20 thread2 : number = 11 21 thread3 : number = 12 22 thread2 : number = 13 23 thread1 : number = 14 24 thread3 : number = 15 25 thread3 : number = 16 26 thread2 : number = 17 27 thread1 : number = 18 28 thread3 : number = 19 29 thread2 : number = 20 30 thread3 : number = 21 31 thread1 : number = 22 32 thread3 : number = 23 33 thread2 : number = 24 34 thread3 : number = 25 35 thread2 : number = 26 36 thread1 : number = 27 37 thread3 : number = 28 38 thread3 : number = 29 39 thread2 : number = 30 40 thread1 : number = 31 41 Thread3 :main函数在等我完成任务吗？ 42 Thread2 :main函数在等我完成任务吗？ 43 Thread1 :main函数在等我完成任务吗？ 44 线程1已经结束 45 线程2已经结束 46 线程3已经结束
代码如下：参考网上的，稍微修改了下：否则，不能编译和运行：
1 //fileName: threadSample.c
2 #include <pthread.h>
3 #include <stdio.h>
4 #include <sys/time.h>
5 #include <string.h>
6 #include <unistd.h> //添加的头文件
7 #define MAX 30
8
9 pthread_t thread[3]; //3个线程
10 pthread_mutex_t mut;
11 int number=0;
12 int i;
13
14 void *thread1(){
15 printf ("Thread1 : I'm thread 1th\n");
16 for (i = 0; i < MAX; i++)
17 {
18 printf("thread1 : number = %d\n",number);
19 pthread_mutex_lock(&mut);
20 number++;
21 pthread_mutex_unlock(&mut);
22 sleep(4);
23 }
24
25 printf("Thread1 :main函数在等我完成任务吗？\n");
26 pthread_exit(NULL);
27 }
28
29 void *thread2(){
30 printf("Thread2 : I'm thread 2nd\n");
31
32 for (i = 0; i < MAX; i++)
33 {
34 printf("thread2 : number = %d\n",number);
35 pthread_mutex_lock(&mut);
36 number++;
37 pthread_mutex_unlock(&mut);
38 sleep(3);
39 }
40
41 printf("Thread2 :main函数在等我完成任务吗？\n");
42 pthread_exit(NULL);
43 }
44
45 void *thread3(){
46 printf("Thread3 : I'm thread 3nd\n");
47
48 for (i = 0; i < MAX; i++)
49 {
50 printf("thread3 : number = %d\n",number);
51 pthread_mutex_lock(&mut);
52 number++;
53 pthread_mutex_unlock(&mut);
54 sleep(2);
55 }
56
57 printf("Thread3 :main函数在等我完成任务吗？\n");
58 pthread_exit(NULL);
59 }
60
61 void thread_create(void){ int temp;
62 memset(&thread, 0, sizeof(thread));
63 /*创建线程*/
64 if((temp = pthread_create(&thread[0], NULL, thread1, NULL)) != 0)
65 printf("线程1创建失败!\n");
66 else
67 printf("线程1被创建\n");
68
69 if((temp = pthread_create(&thread[1], NULL, thread2, NULL)) != 0)
70 printf("线程2创建失败");
71 else
72 printf("线程2被创建\n");
73
74 if((temp = pthread_create(&thread[2], NULL, thread3, NULL)) != 0)
75 printf("线程3创建失败");
76 else
77 printf("线程3被创建\n");
78 }
79
80 void thread_wait(void){
81 /*等待线程结束*/
82 if(thread[0] !=0){
83 pthread_join(thread[0],NULL);
84 printf("线程1已经结束\n");
85 }
86 if(thread[1] !=0){
87 pthread_join(thread[1],NULL);
88 printf("线程2已经结束\n");
89 }
90 if(thread[2] !=0){
91 pthread_join(thread[2],NULL);
92 printf("线程3已经结束\n");
93 }
94 }
95
96 int main()
97 {
98 /*用默认属性初始化互斥锁*/
99 pthread_mutex_init(&mut,NULL);
100
101 printf("主函数正在创建线程，...\n");
102 thread_create();
103 printf("主函数正在等待线程结束...\n");
104 thread_wait();
105
106 return 0;
107 }
再次执行结果为：
1 主函数正在创建线程，... 2 线程1被创建 3 Thread1 : I'm thread 1th 4 thread1 : number = 0 5 Thread2 : I'm thread 2nd 6 thread2 : number = 1 7 线程2被创建 8 线程3被创建 9 主函数正在等待线程结束... 10 Thread3 : I'm thread 3nd 11 thread3 : number = 2 12 thread3 : number = 3 13 thread2 : number = 4 14 thread1 : number = 5 15 thread3 : number = 6 16 thread2 : number = 7 17 thread3 : number = 8 18 thread1 : number = 9 19 thread3 : number = 10 20 thread2 : number = 11 21 thread3 : number = 12 22 thread1 : number = 13 23 thread2 : number = 14 24 thread3 : number = 15 25 thread3 : number = 16 26 thread2 : number = 17 27 thread1 : number = 18 28 thread3 : number = 19 29 thread2 : number = 20 30 thread3 : number = 21 31 thread1 : number = 22 32 thread3 : number = 23 33 thread2 : number = 24 34 thread3 : number = 25 35 thread1 : number = 26 36 thread2 : number = 27 37 thread3 : number = 28 38 thread3 : number = 29 39 thread2 : number = 30 40 thread1 : number = 31 41 Thread3 :main函数在等我完成任务吗？ 42 Thread2 :main函数在等我完成任务吗？ 43 Thread1 :main函数在等我完成任务吗？ 44 线程1已经结束 45 线程2已经结束 46 线程3已经结束
编译方法：gcc threadSample.c -o threadSample -lpthread
代码非常简单，请自行理解吧
来源：https://www.cnblogs.com/guochaoxxl/p/12584529.html