Question

我在下面的代码中遇到错误。它只执行与奇数相关的处理程序（如果父项产生一个奇数随机数，包括在1和10之间），而偶数的那个总是＆＃34;静音＆＃34;。有人可以帮助我吗？

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/msg.h>
#include <sys/types.h>
#include <signal.h>
#include <math.h>

pid_t pid1,pid2;
int r, ric1, ric2;
int fd[4];  //per 2 processi figli

void handler_one(){
    read(fd[0], &ric1, sizeof(int));
    printf("Im the first child process...the even received numebr is...%d\n", ric1);
    sleep(1);
}

void handler_two(){
    read(fd[2], &ric2, sizeof(int));
    printf("I'm the second child process...the odd receiver number is...%d\n", ric2);
    sleep(1);
}

void main(){


    pipe(fd);
    pipe(fd+2);

    pid1=fork();
    if(pid1)
        pid2=fork();

    while(1){
        if(pid1<0 || pid2<0){
            perror("AN ERROR OCCURRED!!!!!!!\n");
            exit(1);
        }
        else if(!pid1 && pid2){ //child #1
            signal(SIGUSR1, handler_one);
        }
        else if(pid1 && !pid2){ //child #2
            signal(SIGUSR2, handler_two);
        }
        else{   //padre
            printf("I'm the parent and I'm gonna send a random number\n");
            r=rand()%10+1;
            if(r%2==0){
                write(fd[1], &r, sizeof(int));
                kill(pid1, SIGUSR1);
            }               
            else{
                write(fd[3], &r, sizeof(int));
                kill(pid2, SIGUSR2);
            }
            sleep(1);
        }

    }
}

Answer 1

设置子1信号处理程序的条件不正确。而不是

library(dplyr)

bind_rows(
  Class %>% 
    mutate(origin = 'not_sampled'),
  Class %>% 
    sample(100, replace = TRUE) %>% 
    mutate(origin = 'sampled'))

应该是

   else if(!pid1 && pid2){ //child #1

不确定您是否保证pid1和pid2被初始化为零，您可能希望明确地这样做。

C信号无法正常工作

1 个答案: