About some logic shopping cart and inventory

• Lock stock when generating orders should be better than the cart lock stock Add to Cart line did not produce the actual purchase behavior;
• Add to Cart, verify inventory is over;
• Pre-orders, verify inventory is over;
• When you create an order, verify inventory is over; at the same time deductions stock! If the inventory shortage, to remind the user, or can not be settled!
• Not pay more than a certain time, cancel orders, inventory and restoration! If paid, will not return in stock!
• Photographed minus inventories, unpaid orders after trading closed, commodity stocks resume immediately; after payment of inventory reduction, refund payment orders lead to closure of inventory are not automatically restored.