Os Process Management Questions Medium
Deadlocks in an operating system occur when two or more processes are unable to proceed because each is waiting for a resource held by another process. To handle deadlocks, operating systems employ various methods, including:
1. Deadlock Prevention: This method focuses on preventing deadlocks from occurring in the first place. It involves ensuring that at least one of the necessary conditions for deadlock cannot hold. This can be achieved by using techniques such as resource allocation denial, where a process is only granted resources if it does not lead to a potential deadlock situation.
2. Deadlock Avoidance: Unlike prevention, avoidance allows for the possibility of deadlocks but employs algorithms to dynamically analyze the resource allocation requests and determine if granting them would lead to a deadlock. The system uses resource allocation graphs or banker's algorithm to make decisions on whether to grant or deny resource requests.
3. Deadlock Detection and Recovery: This method involves periodically checking the system for the presence of deadlocks. Various algorithms, such as the resource allocation graph algorithm or the deadlock detection algorithm, can be used to identify deadlocks. Once a deadlock is detected, the system can take actions to recover from it. Recovery methods include killing one or more processes involved in the deadlock, preempting resources from processes, or rolling back the progress of processes to a safe state.
4. Deadlock Ignorance: Some operating systems choose to ignore the problem of deadlocks altogether. This approach assumes that deadlocks are rare and the cost of implementing deadlock prevention, avoidance, or detection outweighs the potential impact of deadlocks. However, this method can be risky as it may lead to system crashes or resource starvation in case of a deadlock.
It is important to note that no single method is universally applicable to all situations. The choice of method depends on the specific requirements, constraints, and trade-offs of the operating system and the applications running on it.