Threads And Concurrency Questions Medium
Deadlocks can be prevented in a program by implementing various techniques and strategies. Some of the commonly used methods to prevent deadlocks are:
1. Avoidance: This technique involves analyzing the resource allocation graph and determining if a potential deadlock can occur. If a deadlock is detected, the system can choose to deny the request for resources, thereby preventing the deadlock from occurring. However, this approach may lead to low resource utilization and may not be feasible in all scenarios.
2. Detection and Recovery: This technique involves periodically checking the resource allocation graph for potential deadlocks. If a deadlock is detected, the system can take appropriate actions to recover from the deadlock, such as terminating one or more processes or rolling back their actions. However, this approach adds overhead to the system and may not be efficient in real-time systems.
3. Prevention: This technique involves ensuring that at least one of the necessary conditions for deadlock (i.e., mutual exclusion, hold and wait, no preemption, and circular wait) does not hold. For example, by implementing a protocol that ensures resources are requested in a specific order, the circular wait condition can be prevented. However, prevention techniques may be complex to implement and may require significant changes to the system.
4. Resource Allocation Policies: By implementing appropriate resource allocation policies, deadlocks can be prevented. For example, the Banker's algorithm can be used to ensure that resources are allocated in a safe manner, preventing deadlocks. However, these policies may require additional overhead and may not be suitable for all types of systems.
5. Avoiding Hold and Wait: This technique involves ensuring that a process requests all the necessary resources at once, rather than acquiring them one by one. This way, the process will not hold any resources while waiting for others, reducing the chances of deadlocks. However, this approach may lead to resource wastage and may not be feasible in all scenarios.
It is important to note that no single technique can completely eliminate the possibility of deadlocks. The choice of prevention technique depends on the specific requirements and constraints of the system.