Multiple Parallel (concurrent) operations

I have OrderQty, totalConsumedQty, and MaximumOrderQty.

Orders are being placed in parallel.

Each order reads the current totalConsumedQty, adds its OrderQty, and checks if it exceeds MaximumOrderQty.

When multiple orders are placed at exactly the same time, they all see the same original value of totalConsumedQty, and each thinks it’s safe to place the order.

Result: totalConsumedQty is exceeded because updates are not aware of each other.

Updating totalConsumedQty is happens while Saving, It is required