🚀 go-pugleaf

Dear guys,
      I have a difficulty in enforcing the mutual exclusion between
5 philosophers because I couldn't effectively change the global 
variables such as the major semaphore (me), and the private semaphore
(s[i]).  Could anybody suggest an answer for me or comment on my logic
below.  Your kind attention is much appreciated.  Thanks...

  kleung@esk.compserv.utas.edu.au

#include <stdio.h>
#include <sys/types.h>
#define N              6
int  s[N], me;
enum status {nthinking,vhungry,neating} ;
enum status p[N];
main()
{
  int i, ;
  void  PHILOSOPHER(), 
        think(), eat(), hungry();

  me = 1;    /* initial open state of main semaphore */

  for (i=1;i<N;i++) /*initialise 1-5 philosophers to thinking*/
      { s[i] = 0; p[i] = nthinking;}  /* private semaphore s[i]=0,close*/

  for (i=1; i<N; i++){
	if (fork() == 0) PHILOSOPHER(i);
  }
        ..
        ..
  kill(0,9);
}
void PHILOSOPHER(i)
int i;
{
		think(i);
      -----------waitfor(me); 
      !     /* see whether the sem. is open(me=1) or close(me=0)
      !        if me=1, pass thru, and set the me back to 0   */ 
      !		hungry(i);
      !         philosopher i = hungry
      !         printf("\nphil %d has gone into c.s.",i);
      !         check if the lefthand and righthand philosopher 'not eating'  
      !         if it is so,  set itself = eating, release private sem.
      !         of itself : signalto(p[i]) -- supposed to set p[i] = 1
      !         but didn't...... 
      ---------	signalto(me);
		waitfor(s[i]);
		eat(i);
      --------	waitfor(me);
      !           ..
      !           ..
      !         activate the neigbouring philosophers (ready to eat)
      !           ..
      !           .. 
      ----------signalto(me);
                printf("phil %d has finished eating and asking other to eat" );

waitfor(i)
int i;
{
	if (i >= 1)   {  i--; }
	else
	  {  waitfor(i); } 
	return i;
}
signalto(i)
int i;
	{return i++;}