Conservative policies deny resources even when they are available. However, they reduce the likelyhood of deadlock at the expense of reduced concurrency Liberal policies allocate resources when they are available at the risk of entering a deadlock state later. Dining Philosophers Problem Classic problem to demonstrate both deadlock and starvation. Five philosophers seated around a table with ten chopsticks and five rice bowls. Need two chopsticks to eat rice.
Philosophers alternate between thinking and eating.
Want to grant chopsticks while avoiding both deadlock and starvation. The most conservative approach is called serialization . No two processes are allowed to allocate any resources concurrently. Serialization works because all processes must wait for the one process holding resources to complete. Once one drive has been allocated to the first process, the second process would not be granted any request until the first process releases all the resources it holds.