Deadlock avoidance is a technique used in operating systems to dynamically detect and avoid situations that could lead to deadlocks. It involves analyzing the resource allocation state and resource requests made by processes to determine if granting a request would potentially result in a deadlock. The request for any resource will be granted only if the resulting state of the system doesnt cause any deadlock in the system. Deadlock avoidance works by letting the operating system know the process requirements of resources to complete their execution, and accordingly, the operating system checks if the requirements can be met.

The operating system avoids deadlock by knowing the maximum resource requirements of the processes initially, and also, the operating system knows the free resources available at that time. The operating system tries to allocate the resources according to the process requirements and checks if the allocation can lead to a safe state or an unsafe state. If the resource allocation leads to an unsafe state, then the operating system does not proceed further with the allocation sequence.

The key features of deadlock avoidance are:

• Safe State: A state of the system is called safe if the system can allocate all the resources requested by all the processes without entering into deadlock.
• Unsafe State: A state of the system is called unsafe if all of the resource requirements of the process cannot be met by the available resources in any way.
• Resource Allocation Graph: This is a graphical representation of the resource allocation state and resource requests made by processes. The algorithms of deadlock avoidance mainly examine the resource allocations so that there can never be an occurrence of circular wait conditions.

Deadlock avoidance can be done with the help of various techniques such as resource allocation graphs and the bankers algorithm. While deadlock avoidance can be an effective way to prevent deadlocks, it can also be costly in terms of system resources and may result in reduced system performance.