Deadlock
All processes keep waiting for each other to complete and none get executed. Resources are blocked by the processes.A deadlock occurs when no process can proceed and becomes blocked . In other words, a deadlock occurs when multiple processes in the CPU compete for the limited number of resources available in the CPU .Deadlocks typically occur in systems that use resource allocation policies like mutual exclusion, hold and wait, no preemption, and circular wait. Let's discuss each of these conditions:
1)Mutual Exclusion: At least one resource must be held in a non-shareable mode, meaning that only one process can use it at a time. If a process requests a resource that is already held by another process, it must wait until the resource is released.
2)Hold and Wait: A process must be holding at least one resource while waiting to acquire additional resources. If a process holds a resource and requests another that is held by a different process, a situation of deadlock can occur if the second process is also waiting for a resource held by the first process.
3)No Preemption: Resources cannot be forcibly taken away from a process that is currently using them. The only way a resource can be released is voluntarily by the process holding it. This condition contributes to the possibility of deadlock, as processes may hold resources indefinitely.
4)Circular Wait: A set of processes is involved in a circular chain, where each process is waiting for a resource held by the next process in the chain. This circular dependency leads to a situation where no process can proceed.
Starvation
Starvation happens when a low priority program requests a system resource but cannot run because a higher priority program has been employing that resource for a long time.
1)High priority processes keep executing and low priority processes are blocked. Resources are continuously utilized by high priority processes.When a process is ready to start executing, it waits for the CPU to allocate the necessary resources. However, because other processes continue to block the required resources, the process must wait indefinitely.
2)Deadlock: In a deadlock situation, multiple processes are waiting for resources that are held by other processes, forming a circular dependency. If the deadlock resolution policy in the operating system is ineffective, processes may remain deadlocked indefinitely, resulting in resource starvation for those processes.
For example, if a process is granted a large amount of memory and holds onto it for an extended period, other processes may be unable to acquire sufficient memory and may not be able to progress.
3)CPU Scheduling: In a multi-programmed operating system, if a scheduling algorithm always prioritizes certain processes over others, lower-priority processes may starve for CPU time. They may experience delays or never get a chance to execute if higher-priority processes continually occupy the CPU.
