/* ------------------------ sign.c ------------------------ */

# include "sign.h"
# include <stdio.h>
# include <unistd.h>
# include <siginfo.h>

struct sigaction ct_newact, ct_oldact, lm_newact, lm_oldact;
siginfo_t info;

long process = -1 ;
int is_free = 1;
int in_hand = 0;

void lm_handler(int sig, siginfo_t * info){
/* second argument: Flag SA_SIGINFO, see man sigaction */
   while (in_hand) sleep(1);
   in_hand = 1;

   /* printf("signal handler: SIGNAL = >%d<\n",sig);
   printf("Got from >%ld<\n", info->si_pid); */
   if (is_free && (sig == SIGUSR1)) {
      is_free = 0;
      process = info-> si_pid;
         if (kill(info->si_pid,SIGUSR2) < 0 ) {
            perror("kill");
            exit(1);
         }
   } else 
      if ((process == info->si_pid) && (sig == SIGUSR2) ) {
         is_free = 1;
	 process = -1;
      }
   in_hand = 0;
   return;
}

void ct_handler(int sig, siginfo_t * info){
/* second argument: Flag SA_SIGINFO, see man sigaction */
  printf("signal handler: SIGNAL = >%d<\n",sig);
  printf("Got from >%ld<\n", info->si_pid);
  if( sig == SIGUSR2 ) return;
}


Sigfunc install_ct_sig(int sig) {
   ct_newact.sa_handler = ct_handler;
   if (sigemptyset(&ct_newact.sa_mask) < 0) return SIG_ERR;
   ct_newact.sa_flags = 0;
   ct_newact.sa_flags = SA_SIGINFO;
      /*SA_SIGINFO -> man sigaction */
   if (sigaction(sig, &ct_newact, &ct_oldact) < 0)
      return SIG_ERR;
   else
      return ct_oldact.sa_handler;
}


Sigfunc install_lm_sig(int sig) {
   lm_newact.sa_handler = lm_handler;
   if (sigemptyset(&lm_newact.sa_mask) < 0) return SIG_ERR;

   sigaddset(&lm_newact.sa_mask, SIGUSR1);
   sigaddset(&lm_newact.sa_mask, SIGUSR2);

   lm_newact.sa_flags = 0;
   lm_newact.sa_flags = SA_ONSTACK | SA_RESTART | SA_SIGINFO;

   if (sigaction(sig, &lm_newact, &lm_oldact) < 0)
      return SIG_ERR;
   else
      return lm_oldact.sa_handler;
}