void
PC_Put(PC *pc, int color)
{
Lock_Acquire(&pc->lock);
assert(color <= pc->maxColor);
while(pc->capacity == pc->used){
pc->waitingP++;
Cond_Wait(&pc->spaceAvail, &pc->lock);
pc->waitingP--;
}
pc->used++;
addItem(color, &(pc->list));
assert(((Item *)List_Last(&(pc->list)))->color == color);
if(pc->used == 1){
/*
* Went from empty to non-empty. Signal
*/
if(pc->maxColor == 0){
Cond_Signal(&pc->stuffAvail, &pc->lock);
}
else{
Cond_Broadcast(&pc->stuffAvail, &pc->lock);
}
}
assert(((Item *)List_Last(&(pc->list)))->color == color);
Lock_Release(&pc->lock);
}
/* Attempt to make a (hungry) philosopher i to start eating */
void trytoeat(int i)
{
if(state[i]==HUNGRY && state[LEFT(i)]!=EATING && state[RIGHT(i)]!=EATING) {
state[i] = EATING;
print_state(" %d is eating\n",i);
Cond_Signal(&(hungry[i]));
}
}
int
PC_Get(PC *pc, int color)
{
Lock_Acquire(&pc->lock);
assert(color <= pc->maxColor);
while(List_IsEmpty(&(pc->list))
|| (((Item *)List_First(&(pc->list)))->color != color)){
pc->waitingC++;
Cond_Wait(&pc->stuffAvail, &pc->lock);
pc->waitingC--;
}
removeItem(color, &(pc->list));
pc->used--;
Cond_Signal(&pc->spaceAvail, &pc->lock);
/*
* We just took top item off -- another getter may be
* able to proceed
*/
Cond_Broadcast(&pc->stuffAvail, &pc->lock);
Lock_Release(&pc->lock);
return color;
}
