线程处理函数pthread_cleanup_push / pthread_cleanup_pop

叁歲伎倆 2022-06-02 12:19 308阅读 0赞

####         **     线程处理函数pthread\_cleanup\_push / pthread\_cleanup\_pop** ####

线程可以安排它退出线程处理函数pthread\_cleanup\_push / pthread\_cleanup\_pop时需要调用的函数，这样的函数称为线程清理处理程序，线程可以建立多个清理处理程序。处理程序记录在栈中，也就是说它们的执行顺序与它们注册时的顺序相反。

pthread\_cleanup\_push来注册清理函数rtn,这个函数有一个参数arg。在以下三种情形之一发生时，注册的清理函数被执行：  
    1）调用pthread\_exit。  
    2）作为对取消线程请求(pthread\_cancel)的响应。  
    3）以非0参数调用pthread\_cleanup\_pop。  
注意：

1）如果线程只是由于简单的返回而终止的，则清除函数不会被调用。

2）如果pthread\_cleanup\_pop被传递0参数，则清除函数不会被调用，但是会清除处于栈顶的清理函数。

<table style="border-collapse:collapse; border-spacing:0px; max-width:100%; background-color:transparent; margin:auto 6.75pt"> 
 <tbody style=""> 
 <tr style="height:15.5pt"> 
 <td style="border-width:1pt; border-style:solid; border-color:windowtext; padding:0cm 5.4pt; background-color:transparent; width:96.05pt; height:15.5pt"> 名称： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; width:333.05pt; height:15.5pt; border-left-color:rgb(236,233,216); border-top:1pt solid windowtext; border-right:1pt solid windowtext"> pthread_cleanup_push / pthread_cleanup_pop </td> 
 </tr> 
 <tr style="height:14.75pt"> 
 <td style="border-bottom:1pt solid windowtext; border-left:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:96.05pt; height:14.75pt; border-right:1pt solid windowtext"> 功能： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:333.05pt; height:14.75pt; border-left-color:rgb(236,233,216); border-right:1pt solid windowtext"> 线程清理处理程序 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-bottom:1pt solid windowtext; border-left:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:96.05pt; height:15.5pt; border-right:1pt solid windowtext"> 头文件： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:333.05pt; height:15.5pt; border-left-color:rgb(236,233,216); border-right:1pt solid windowtext"> #include &lt;pthread.h&gt; </td> 
 </tr> 
 <tr style="height:12.1pt"> 
 <td style="border-bottom:1pt solid windowtext; border-left:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:96.05pt; height:12.1pt; border-right:1pt solid windowtext"> 函数原形： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:333.05pt; height:12.1pt; border-left-color:rgb(236,233,216); border-right:1pt solid windowtext"> void pthread_cleanup_push(void (*rtn)(void *)，void *arg); void pthread_cleanup_pop(int execute); </td> 
 </tr> 
 <tr style="height:10.95pt"> 
 <td style="border-bottom:1pt solid windowtext; border-left:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:96.05pt; height:10.95pt; border-right:1pt solid windowtext"> 参数： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:333.05pt; height:10.95pt; border-left-color:rgb(236,233,216); border-right:1pt solid windowtext"> rtn处理程序入口地址 arg传递给处理函数的参数 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-bottom:1pt solid windowtext; border-left:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:96.05pt; height:15.5pt; border-right:1pt solid windowtext"> 返回值： </td> 
 <td style="border-bottom:1pt solid windowtext; padding:0cm 5.4pt; background-color:transparent; border-top-color:rgb(236,233,216); width:333.05pt; height:15.5pt; border-left-color:rgb(236,233,216); border-right:1pt solid windowtext"> 无 </td> 
 </tr> 
 </tbody> 
</table>

\[cpp\]  [view plain][]  [copy][view plain]

1. \#include <stdio.h>    
2. \#include <stdlib.h>    
3. \#include <pthread.h>    
4. \#include <string.h>    
5.    
6. void cleanup(void \*arg)\{    
7.     printf("cleanup: %s/n",(char \*)arg);    
8. \}    
9.    
10. void \*thr\_fn1(void \*arg)\{    
11.     printf("thread 1 start/n");    
12.     pthread\_cleanup\_push(cleanup,"thread 1 first handler");    
13.     pthread\_cleanup\_push(cleanup,"thread 1 second handler");    
14.     printf("thread 1 push complete/n");    
15.     if(arg)    
16.         return ((void \*)1);    
17.     pthread\_cleanup\_pop(1);    
18.     pthread\_cleanup\_pop(1);    
19.     return ((void \*)1);    
20. \}    
21.    
22. void \*thr\_fn2(void \*arg)\{    
23.     printf("thread 2 start/n");    
24.     pthread\_cleanup\_push(cleanup,"thread 2 first handler");    
25.     pthread\_cleanup\_push(cleanup,"thread 2 second handler");    
26.     printf("thread 2 push complete/n");    
27.     if(arg)\{    
28.         pthread\_exit((void \*)2);    
29.     \}    
30.     pthread\_cleanup\_pop(0);  //取消第一个线程处理程序  
31.   
32.     pthread\_cleanup\_pop(0);  //取消第二个线程处理程序  
33.    
34.     pthread\_exit((void \*) 2);    
35. \}    
36.    
37. int main(void)\{    
38.     int err;    
39.     pthread\_t tid1,tid2;    
40.     void \*tret;    
41.    
42.     err = pthread\_create(&tid1,NULL,thr\_fn1,(void \*)1);    
43.     if( err != 0)\{    
44.         fprintf(stderr,"create thread1 failed: %s",strerror(err));    
45.         exit(1);    
46.     \}    
47.    
48.     err = pthread\_create(&tid2,NULL,thr\_fn2,(void \*)2);    
49.     if(err != 0)\{    
50.         fprintf(stderr,"create thread 2 failed: %s",strerror(err));    
51.         exit(1);    
52.     \}    
53.    
54.     err = pthread\_join(tid1,&tret);    
55.     if(err != 0)\{    
56.         fprintf(stderr,"thread1 join failed: %s",strerror(err));    
57.         exit(1);    
58.     \}    
59.     printf("thread 1 exit code %d/n",(int)tret);    
60.     err = pthread\_join(tid2,&tret);    
61.     if(err != 0)\{    
62.         fprintf(stderr,"thread2 join failed: %s",strerror(err));    
63.         exit(1);    
64.     \}    
65.     printf("thread 2 exit code %d/n",(int) tret);    
66.     exit(0);     
67. \}

补充一下: phtread\_cleanup\_push 与 phread\_cleanup\_pop要成对儿的出现，否则会报错！！

[view plain]: http://blog.csdn.net/mxgsgtc/article/details/11898993#