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Can't kill child processes with SIGQUIT in cygwin

I'm working on cygwin to test out Linux system programming. My problem is while using the signals. I want to create n processes that the parent process will kill when it receives the signal SIGALRM that will be sent by the child. Everychild sends an alarm so n alarms will be sent and the n childs should be killed.

I'm getting a problem when I execute the program but I don't know if I'm doing something wrong or if cygwin cann't do this.

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

int nb;
pid_t* p;

void handler(int s) {
    signal(s, handler);
    for(int i=0; i<nb; i++) {
        printf("%d killed\n", p[i]);
        kill(p[i], SIGQUIT);
    }
}

int main(int arc, char* argv[]) {
    signal(SIGALRM, handler);
    int n=atoi(argv[1]);
    nb=n;
    p=(pid_t*)malloc(nb*sizeof(pid_t));
    for(int i=0; i<nb; i++) {
        if((p[i]=fork())==0) {
            printf("child : %d\n", getpid());
            alarm(1);
            for(;;);
            exit(0);
        }
    }
    printf("parent : %d\n", getpid());
    pause();
    exit(0);
}

With this, the childs should be quitting but I'm getting some weird things when I execute:

$ ./a.out 5
child : 1048
child : 1049
child : 1050
child : 1051
parent : 1047
child : 1052
0 killed
Stack trace:
Frame        Function    Args
000FFFFC7D0  00180060BE9 (00000000000, 000FFFFCE00, 000FFFFC9D8, 000FFFFDE50)
00000000002  00180062ABA (00000000000, 001800FE6C8, 000FFFFC9B0, 00000000000)
000FFFFCBD0  00180128550 (00000000000, 001800FE6C8, 000FFFFC9B0, 00000000000)
000FFFFCBD0  001004011C4 (00000000000, 00000000000, 00000000000, 00000000000)
000FFFFC5E0  001004011C4 (7FFBE56E6A08, 00000000000, 3734EC77843980, 000FFFFC830)
000FFFFC830  00068040004 (7FFBE56E6A08, 00000000000, 3734EC77843980, 000FFFFC830)
End of stack trace
Stack trace:
Frame        Function    Args
000FFFFC7D0  00180060BE9 (00000000000, 000FFFFCE00, 000FFFFC9D8, 000FFFFDE50)
Stack trace:
Frame        Function    Args
00000000002  00180062ABA000FFFFC7D0  00180060BE9 (00000000000 (00000000000, 000FFFFCE00Stack trace:
Frame        Function    Args
, 001800FE6C8000FFFFC080  00180060BE9, 000FFFFC9B0, 00000000000)
000FFFFCBD0  00180128550 (00000000000 (00000000000, 000FFFFCE00, 000FFFFC288, 001800FE6C8, 000FFFFDE50, 000FFFFC9B0)
, 00000000000)
000FFFFCBD0  001004011C4 (00000000000, 00000000000, 00000000000, 00000000000)
00000000002  00180062ABA, 000FFFFC9D8, 000FFFFDE50)
00000000002  00180062ABA (00000000000 (00000000064, 001800FE6C8Stack trace:
Frame        Function    Args
, 000FFFFC9B0, 00000000000)
000FFFFCBD0  00180128550 (00000000000000FFFFC5E0  001004011C4 (7FFBE56E6A08, 001800FE6C8, 00000000000, 000FFFFC9B0000FFFFC7D0  00180060BE9 (00000000000, 0000000017C, 00000000000, 3734EC77862237, 000FFFFC830, 00000000000, 000FFFFCE00)
, 00000000000)
, 000FFFFC9D8000FFFFCBD0  001004011C4 (00000000000, 00000000000, 00000000000, 000FFFFDE50, 00000000000)
000FFFFC830  00068040004)
000FFFFC5E0  001004011C4 (7FFBE56E6A08, 00000000000)
 (7FFBE56E6A0800000000002  00180062ABA (00000000000000FFFFC360  00180130B1B (000FFFFC514, 001800FE6C8, 00000000000, 3734EC77862237, 000FFFFC830, 3734EC778A3B1B, 00000000001, 000FFFFC830, 000FFFFC9B0)
, 00000000000, 00100000000)
End of stack trace
, 00000B74440000FFFFC830  00068040004 (7FFBE56E6A08, 00000000000)
, 3734EC778A3B1B)
000FFFFCBD0  00180128550 (00000000000, 000FFFFC830, 001800FE6C8)
, 000FFFFC9B0End of stack trace
000FFFFC700  0018012CAAE, 00000000000)
 (7FFBE56EC859000FFFFCBD0  001004011C4, 00000000001 (00000000000, 7FFBE56E3533, 00000000000, 00000000001, 00000000000, 00000000000)
000FFFFC5E0  001004011C4)
 (7FFBE56E6A08000FFFFC5F0  0018012CE7F, 00000000000 (00100000000, 3734EC7788519E, 000FFFFC830, 00000000000, 0018021E2DC, 0000000000D)
)
000FFFFC7E0  0018012CFDC000FFFFC830  00068040004 (000FFFFC7D0 (7FFBE56E6A08, 000FFFFC830, 00000000000, 3734EC7788519E, 000FFFFC830)
End of stack trace
, 000FFFFC780, 00000000003)
000FFFFC7E0  0018012D180 (00000000000, 00010000000, 00000002000, 00000000138)
000FFFFC7E0  0018012842B (00000000000, 00010000000, 00000002000, 00000000138)
000FFFFC7E0  001004010EF (00180240A28, 001800FE3B0, C85632670B110000, 0018027EF00)
00010000000  00180062ABA (00000000000, 001800FE6C8, 000FFFFC9B0, 00000000000)
000FFFFCBD0  00180128550 (00000000000, 001800FE6C8, 000FFFFC9B0, 00000000000)
000FFFFCBD0  001004011C4 (00000000000, 00000000000, 00000000000, 00000000000)
000FFFFC5E0  001004011C4 (001E56E6A08, 0C800000000, 00600048640, 00600048970)
000FFFFC830  00068040004 (001E56E6A08, 0C800000000, 00600048640, 00600048970)
End of stack trace
Quit (core dumped)

Can I fix this ?

Solution

  • I solved it by using SIGKILL instead of SIGQUIT