program p;



unit sync : process(nr:integer);

   unit slock:procedure;
      begin
      accept sunlock;
   end slock;

   unit sunlock:procedure;
      begin
   end sunlock;

   begin
   return;
   do
      accept slock;
   od;
end sync;



unit main_process : process( i:integer, s:sync );

   var cnt : integer;

   unit entry : procedure( i,j:integer );
      begin
      writeln("entry called from node ",i," #",j);
      if j<0 then cnt:=cnt+1; fi;
   end entry;

   begin
   cnt := 0;
   return;
   while  cnt < 2  do
      accept entry;
   od;
   call s.sunlock;
end main_process;



unit slave : process( i:integer, m:main_process );
   var j:integer;
   begin
   return;
   for j:=1 to 10 do
      call m.entry( i, j );
   od;
   call m.entry( i, -1 );
end slave;


unit ender : process( i:integer );
   begin
   return;
   call endrun;
end ender;


var m:main_process, s1,s2:slave, sem:sync, e:ender;

begin

   sem := new sync( 0 );
   resume( sem );

   m := new main_process( 0, sem );
   resume( m );

   s1 := new slave( 2, m );
   resume( s1 );
   s2 := new slave( 3, m );
   resume( s2 );
   call sem.slock;

   e := new ender( 2 );
   resume( e );
   e := new ender( 3 );
   resume( e );

   writeln("end of program");
   call endrun;

end.