linux sigaction and sigqueue

#include<stdio.h>
#include<stdlib.h>
#include<signal.h>
/*father process send signal to son*/

//下面这个处理函数只执行了第一行，原因不明
void dd(int a,siginfo_t *t,void *v)
{
   printf("a=%d,signo=%d,sigcode=%d,send pid=%d,value=%s\n",a,
          t->si_signo,t->si_code,
          t->si_pid,(char*)(t->si_ptr));
//   sleep(2);
   printf("receive value from process,the value equal/n");
}
main()
{
  //int r;
  pid_t r;
  r=fork();
  if(r!=0)
  {
   printf("father process\n");
   //father process
   sleep(2);
   union sigval val;
    val.sival_ptr="helloworld";
   sigqueue(r,59,val);
  }else{
   //son process
   printf("son process\n");
   //registe signal deal function
   struct sigaction act={};
   act.sa_flags=SA_SIGINFO;
   act.sa_sigaction=dd;
   sigaction(59,&act,0);
   sleep(5000);
   while(1);
  }
}