What is Deadlock?
Deadlock is a situation in computing where two or more processes are unable to proceed because each is waiting for the other to release resources. Key concepts include mutual exclusion, resource holding, circular wait, and no preemption.
Consider an example when two trains are coming toward each other on the same track and there is only one track, none of the trains can move once they are in front of each other. This is a practical example of deadlock.
How Does Deadlock occur in the Operating System?
Before going into detail about how deadlock occurs in the Operating System, let’s first discuss how the Operating System uses the resources present. A process in an operating system uses resources in the following way.
Requests a resource
Use the resource
Releases the resource
A situation occurs in operating systems when there are two or more processes that hold some resources and wait for resources held by others. For example,Process 1 is holding Resource 1 and waiting for resource 2 which is acquired by process 2, and process 2 is waiting for resource 1.
Necessary Conditions for Deadlock in OS
Deadlock can arise if the following four conditions hold simultaneously (Necessary Conditions)
1.Mutual Exclusion: Two or more resources are non-shareable (Only one process can use at a time).
2.Hold and Wait: A process is holding at least one resource and waiting for resources.
3.No Preemption: A resource cannot be taken from a process unless the process releases the resource.
4.Circular Wait: A set of processes waiting for each other in circular form.
What is Deadlock Detection?
Deadlock detection is a process in computing where the system checks if there are any sets of processes that are stuck waiting for each other indefinitely, preventing them from moving forward. In simple words, deadlock detection is the process of finding out whether any process are stuck in loop or not.
