Summary of Deadlock strategies

Table 3.1: Summary of Deadlock strategies

Principle	Resource Allocation Strategy	Different Schemes	Major Advantages	Major Disadvantages
DETECTION	Very liberal; grant resources as requested	Invoke periodically to test for deadlock	1- Never delays process initiation 2- Facilitates on-line handling	Inherent preemption losses
PREVENTION	Conservative; undercommits resources	Requesting all resources at once	1-Works well for processes with single burst of activity 2- No preemption is needed	1- Inefficient 2-Delays process initiation
		Preemption	Convenient when applied to resources whose state can be saved and restored easily	1- Preempts more often then necessary 2-Subject to cyclic restart
		Resource ordering	1- Feasible to enforce via compile time checks 2- Needs no run-time computation	1- Preempts without immediate use 2- Disallows incremental resource requests
AVOIDANCE	Selects midway between that of detection and prevention	Manipulate to find at least one safe path	No preemption necessary	1- Future resource requirements must be known 2- Processes can be blocked for long periods