DATA: condition can_eat[NUM_PHILS]; enum states state[NUM_PHILS-1]; int index; INITIALIZATION: for (index=0; index<NUM_PHILS; index++) MONITOR PROCEDURES: /* request the proper to pickup chopsticks and eat */ entry void pickup(int mynum) are not feeding, proceed */ if ((state[mynum-1 mod NUM_PHILS] != EATING) && (state [mynum+1 mod NUM_PHILS] != EATING)) /* otherwise await them */ else able to eat currently */ state[mynum] = EATING; } } /* announce that we\'re finished, provide others an opportunity */ entry void putdown(int mynum) { /* announce that we\'re done */ state[mynum] = THINKING; /* provide left (lower) neighbor an opportunity to eat */ if ((state [mynum-1 mod NUM_PHILS] == HUNGRY) && (state [mynum-2 mod NUM_PHILS] != EATING)) /* provide right (higher) neighbor an opportunity to eat */ if ((state [mynum+1 mod NUM_PHILS] == HUNGRY) && (state [mynum+2 mod NUM_PHILS] != EATING)) } PHILOSOPHER: /* resolve our id, then repeat forever */ American state = get_my_id(); whereas (TRUE) lie with all once more ... */ think(); pickup(me); eat(); putdown(me); } Solution DATA: condition can_eat[NUM_PHILS]; enum states state[NUM_PHILS-1]; int index; INITIALIZATION: for (index=0; index<NUM_PHILS; index++) MONITOR PROCEDURES: /* request the proper to pickup chopsticks and eat */ entry void pickup(int mynum) are not feeding, proceed */ if ((state[mynum-1 mod NUM_PHILS] != EATING) && (state [mynum+1 mod NUM_PHILS] != EATING)) /* otherwise await them */ else able to eat currently */ state[mynum] = EATING; } } /* announce that we\'re finished, provide others an opportunity */ entry void putdown(int mynum) { /* announce that we\'re done */ state[mynum] = THINKING; /* provide left (lower) neighbor an opportunity to eat */ if ((state [mynum-1 mod NUM_PHILS] == HUNGRY) && (state [mynum-2 mod NUM_PHILS] != EATING)) /* provide right (higher) neighbor an opportunity to eat */ if ((state [mynum+1 mod NUM_PHILS] == HUNGRY) && (state [mynum+2 mod NUM_PHILS] != EATING)) } PHILOSOPHER: /* resolve our id, then repeat forever */ American state = get_my_id(); whereas (TRUE) lie with all once more ... */ think(); pickup(me); eat(); putdown(me); }.

1. DATA:
condition can_eat[NUM_PHILS];
enum states state[NUM_PHILS-1];
int index;
INITIALIZATION:
for (index=0; index<NUM_PHILS; index++)
MONITOR PROCEDURES:
/* request the proper to pickup chopsticks and eat */
entry void pickup(int mynum) are not feeding, proceed */
if ((state[mynum-1 mod NUM_PHILS] != EATING) &&
(state [mynum+1 mod NUM_PHILS] != EATING))
/* otherwise await them */
else able to eat currently */
state[mynum] = EATING;
}
}
/* announce that we're finished, provide others an opportunity */
entry void putdown(int mynum) {
/* announce that we're done */
state[mynum] = THINKING;
/* provide left (lower) neighbor an opportunity to eat */
if ((state [mynum-1 mod NUM_PHILS] == HUNGRY) &&
(state [mynum-2 mod NUM_PHILS] != EATING))
/* provide right (higher) neighbor an opportunity to eat */
if ((state [mynum+1 mod NUM_PHILS] == HUNGRY) &&
(state [mynum+2 mod NUM_PHILS] != EATING))
}
PHILOSOPHER:
/* resolve our id, then repeat forever */
American state = get_my_id();
whereas (TRUE) lie with all once more ... */
think();
pickup(me);
eat();
putdown(me);

2. }
Solution
DATA:
condition can_eat[NUM_PHILS];
enum states state[NUM_PHILS-1];
int index;
INITIALIZATION:
for (index=0; index<NUM_PHILS; index++)
MONITOR PROCEDURES:
/* request the proper to pickup chopsticks and eat */
entry void pickup(int mynum) are not feeding, proceed */
if ((state[mynum-1 mod NUM_PHILS] != EATING) &&
(state [mynum+1 mod NUM_PHILS] != EATING))
/* otherwise await them */
else able to eat currently */
state[mynum] = EATING;
}
}
/* announce that we're finished, provide others an opportunity */
entry void putdown(int mynum) {
/* announce that we're done */
state[mynum] = THINKING;
/* provide left (lower) neighbor an opportunity to eat */
if ((state [mynum-1 mod NUM_PHILS] == HUNGRY) &&
(state [mynum-2 mod NUM_PHILS] != EATING))
/* provide right (higher) neighbor an opportunity to eat */
if ((state [mynum+1 mod NUM_PHILS] == HUNGRY) &&
(state [mynum+2 mod NUM_PHILS] != EATING))
}
PHILOSOPHER:
/* resolve our id, then repeat forever */
American state = get_my_id();
whereas (TRUE) lie with all once more ... */
think();

3. pickup(me);
eat();
putdown(me);
}