c - How to make a process continue it's execution when it's waiting a signal with pause() and it doesn't recieve it -

i'm new forum , i've been googling , searching here problem didn't find it. anyway i'm not expert in searching in forum please excuse me if has been answered. ok let's point: i'm doing small project college have following code written in c:

#include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <signal.h>  int arb,a,b,x,y,z,i;  void senyal(){ //signal usr1 method   if(getpid()==a){     printf("i'm process, i've received signal\n");     system("pstree");    }    else if(getpid()==b){     printf("i'm b process, i've received signal\n");     system("pstree");   }   else if(getpid()==x){     printf("i'm x process, i've received signal\n");     execlp("ls", "ls", "-al", "*.c", null);   }   else if(getpid()==y){     printf("i'm y process, i've received signal\n");     execlp("ls", "ls", "-al", "*.c", null);   } }  int main (int argc, char *argv[]){  char p=argv[1][0];  int num=(int)p;    pid_t pid;   pid_t pid2;   pid_t pid3;   arb=getpid();   pid=fork(); //creates father arb , child     if(pid==-1){         printf ("error");         }     else if(pid==0){ // child         printf ("i'm process: pid %d. father %d \n",getpid(), arb);         a=getpid();      if(num==65||num==97){        num=a;}     pid2=fork(); //a father , creates b child           if(pid2==-1){       printf ("error2");}           else if(pid2==0){// b child          b=getpid();          if(num==66||num==98){            num=b;}         printf("i'm b process , pid %d. father %d. grandfather %d \n",getpid(),getppid(),arb);         pid3=fork();//creates x           switch(pid3){         case -1: printf("error3");              break;         case 0:  printf("i'm  x process, pid %d. father %d. grandfather %d. great grandfather %d\n",getpid(),getppid(),a,arb);              x=getpid();               if(num==88||num==120){                 num=x;}              signal(10,senyal);              printf("i'm x (%d) , die\n",x);              exit(x);              break;         default:               break;           }        pid3=fork();//creates y             switch(pid3){         case -1: printf("error no podido crear el proceso hijo\n");              break;         case 0:  printf(i'm  y process, pid %d. father %d. grandfather %d. great grandfather %d\n",getpid(),getppid(),a,arb);                  y=getpid();               if(num==89||num==121){                 num=y;}              signal(10,senyal);              printf("i'm y (%d) , die\n",y);              exit(y);              break;         default:                break;           }           pid3=fork();//creates z            switch(pid3){         case -1: printf("couldn't create children proccess\n");               break;         case 0:  printf("i'm  z process, pid %d. father %d. grandfather %d. great grandfather %d\n",getpid(),getppid(),a,arb);              z=getpid();              printf("i'm z (%d) , die\n",z);              sleep(argc); //               kill(num,sigusr1);//sends signal of other process (a/b/x/y)              exit(z);               break;         default:               break;           }         wait();//wait childrens' death         wait();         wait();         printf("i'm b(%d) , die\n",b);         exit(b);//b's death       }            else{//father         signal(10,senyal);         wait();//await b's death         printf("i'm (%d) , die\n",a);         exit(a); //a's death        }      }         else{//padre arb        printf ("\ni'm process arb: pid %d\n",getpid());           signal(10,senyal);        wait();  //await a's death             } wait();                          printf("i'm arb (%d) , die\n",arb); exit (0);//arb's death  } 

so code supposed create proccess tree , receive parametrer indicates pid of proccess needs recieve signal of type usgr1 process z sending. problem here want every process prepared receive signal, in case process doesn't recieve (for example process waiting , ready receive signal z z sends b) don't know how tell process go on , not stuck in pause forever. that's it, sorry if commited grammar or explanation errors i'm spain way. willing answer!

from man page of pause():

description

pause() causes calling process (or thread) sleep until signal delivered either terminates process or causes invocation of signal-catching function.

so need thread delays sleep() or similar , sends signal anyway after while. or use else pause, sleep.