Concurrency: Deadlock and Starvation

These flashcards cover key concepts and definitions related to deadlock and starvation in operating systems.

Deadlock

The permanent blocking of a set of processes that either compete for system resources or communicate with each other.

Mutual Exclusion

Only one process may use a resource at a time, according to Coffman's conditions.

Hold-and-Wait

A process may hold allocated resources while awaiting assignment of others.

No Preemption

No resource can be forcibly removed from a process holding it.

Circular Wait

A closed chain of processes exists where each process holds at least one resource needed by the next process in the chain.

Deadlock Prevention

Adopting a policy that eliminates one of the conditions necessary for deadlock.

Deadlock Avoidance

Making dynamic choices based on the current state of resource allocation to avoid deadlock.

Deadlock Detection

Attempting to detect the presence of deadlock and taking action to recover.

Banker’s Algorithm

A strategy for resource allocation that ensures a safe state by not granting requests that might lead to deadlock.

Resource Allocation Graph

A directed graph that represents the allocation of resources to processes and their requests.

Dining Philosophers Problem

A problem that illustrates synchronization issues in concurrent programming, where philosophers share forks.

Semaphore

A synchronization primitive that controls access by multiple processes to a common resource.

Safe State

A state where there is at least one sequence of resource allocations to processes that does not lead to deadlock.

Unsafe State

A state that is not safe and may lead to deadlock.

Starvation

A situation where a process does not get the resources it needs for execution, preventing it from progressing.

Reusable Resources

Resources that can be safely used by only one process at a time and are not depleted by that use.

Consumable Resources

Resources that can be created and destroyed, such as messages and information in I/O buffers.

Detection Algorithm

A method to identify deadlocked processes based on current states of resource allocation.

Resource Categories

Classification of resources into reusable and consumable based on their use and allocation.

Process Initiation Denial

A deadlock avoidance strategy where a process is not started if it might lead to deadlock.

Incremental Resource Request

A request for additional resources by a process that may potentially lead to deadlock.