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[Linux]关于sigprocmask函数的讨论 

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <string.h>
 4 #include <unistd.h>
 5 #include <signal.h>
 6 #include <assert.h>
 7 
 8 void printSignal()
 9 {
10     sigset_t set;
11     int ret = 0;
12     sigemptyset(&set);
13     ret = sigpending(&set);    
14     int i = 1;
15     for (i = 1; i < 65; i++)
16     {
17         if (0 == (ret = sigismember(&set, i)))
18         {
19             printf("0");
20         }
21         else if (1 == ret)
22         {
23             printf("1");
24         }
25     }
26     puts("");
27 }
28 
29 void my_sigaction (int num, siginfo_t *st, void *dat)
30 {
31     int ret = 0;
32     if (SIGINT == num)
33     {
34         sigset_t set;
35         sigemptyset(&set);
36         ret = sigaddset(&set, SIGQUIT);
37         assert(-1 != ret);
38         ret = sigprocmask(SIG_UNBLOCK, &set, NULL);
39         assert(-1 != ret);
40         printf("my_sigaction\n");
41         printSignal();
42         printf("func myhandler num = %d\n", num);        
43     }
44     else
45     {
46         printf("signal is  no SIGQUIT\n");
47     }
48 }
49 
50 
51 
52 int main(void)
53 {
54     int ret = 0;
55     
56     /* 阻塞信号  */
57     sigset_t set;
58     sigemptyset(&set);
59     ret = sigaddset(&set, SIGQUIT);
60     assert(-1 != ret);
61     ret = sigprocmask(SIG_BLOCK, &set, NULL);
62     assert(-1 != ret);
63     printf("阻塞信号\n");
64     //printSignal();
65     sigemptyset(&set);
66     /* 
67 sigpending 是从未决状态字中读取的， 但是未决信号并不能立即得到block的同步
68 也就是说在block置1时pending并不能够立即的更新为1 
69 */
70     //sigpending(&set);
71     
72     /* 注册信号 */
73     struct sigaction act;
74     act.sa_sigaction = my_sigaction;
75     ret = sigemptyset(&(act.sa_mask));
76     assert(-1 != ret);
77     ret = sigaction(SIGINT, &act, NULL);
78     assert(-1 != ret);
79     printf("注册信号\n");
80     printSignal();
81     
82     while (1)
83     {
84         printSignal();
85         sleep(1);
86     }
87     return 0;
88 }

 

posted @ 2017-03-03 20:06  bangiao  阅读(606)  评论(0)    收藏  举报