Question

我的代码C Unix出了问题。我将复制关键部分：所以在第一个sigprocmask之后我发送一个信号，在SIG_UNBLOCK之后，没有工作前一个句柄（gestisciSignalDopoReg）而不是标准句柄来管理我的信号，所以它只是终止进程......出了什么问题？感谢

struct sigaction gestoreSegnale;
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask,SIGTERM);
sigaddset(&mask,SIGINT);
sigaddset(&mask,SIGALRM);
sigaddset(&mask,SIGQUIT);
sigaddset(&mask,SIGHUP);
sigaddset(&mask,SIGSEGV);
sigaddset(&mask,SIGILL);
sigaddset(&mask,SIGPIPE);
void setSegnali(int segn,__sighandler_t handler){
  gestoreSegnale.sa_handler=handler;
  gestoreSegnale.sa_mask=mask;

  sigaction(segn, &gestoreSegnale, NULL);
}
void eseguiSetSegnali(__sighandler_t handler){
  setSegnali(SIGQUIT, handler);
  setSegnali(SIGSEGV, handler);
  setSegnali(SIGILL, handler);
  setSegnali(SIGHUP, handler);
  setSegnali(SIGTERM, handler);
  setSegnali(SIGINT, handler);
}
void main(){
 eseguiSetSegnali(gestisciSIGNALDopoReg);
 sigprocmask(SIG_BLOCK,&mask,NULL);
 .........other part of code......... 
 sigprocmask(SIG_UNBLOCK,&mask,NULL);
}

请！我需要帮助！

Answer 1

您没有初始化sa_flags的{{1}}字段，因此它可能包含垃圾值。有可能设置了struct sigaction位，根据手册页将为您提供此行为：

SA_RESETHAND

如果你的信号处理程序运行了一次，那么它将被清除并返回默认值，所以你可能只需将标记清零，如：

       SA_RESETHAND
              Restore the signal action to the default state once the signal handler has been called.  This flag  is
              only  meaningful  when establishing a signal handler.  SA_ONESHOT is an obsolete, non-standard synonym
              for this flag.

无论如何，以下小例子有效：

void setSegnali(int segn,__sighandler_t handler){
  gestoreSegnale.sa_handler=handler;
  gestoreSegnale.sa_mask=mask;
  /* Make sure to clear flags */
  gestoreSegnale.sa_flags=0;

  sigaction(segn, &gestoreSegnale, NULL);
}

如果运行，您会看到所需的结果：

#include <signal.h>
#include <stdio.h>

void handler(int sig) {
    printf("HUP %d\n", sig);
}

void main(){
    struct sigaction act;

    /* Block SIGHUP while the signal handler is running */
    sigemptyset(&act.sa_mask);
    sigaddset(&act.sa_mask,SIGHUP);

    /* Define handler for signal */
    act.sa_handler = handler;

    /* Clear flags */
    act.sa_flags = 0;
    act.sa_restorer = NULL;

    /* Install handler for SIGHUP */
    sigaction(SIGHUP, &act, NULL);

    /* Set mask to block SIGHUP */
    sigset_t mask;
    sigemptyset(&mask);
    sigaddset(&mask, SIGHUP);

    /* Block SIGHUP */
    printf("Blocking SIGHUP\n");
    sigprocmask(SIG_BLOCK,&mask,NULL);
    printf("Sleeping\n");
    sleep(60);
    /* Unblock SIGHUP */
    printf("Unblocking SIGHUP\n");
    sigprocmask(SIG_UNBLOCK,&mask,NULL);
    printf("Sleeping again\n");
    while(1)
        sleep(60);
}

sigprocmask不会恢复我的信号处理程序

1 个答案: