Starvation

• Starvation describes a situation where a greedy thread holds a resource for a long time so other threads are blocked forever. 

• The blocked threads are waiting to acquire the resource but they never get a chance. Thus they starve to death.

• Starvation can occur due to the following reasons:

• Threads are blocked infinitely because a thread takes long time to execute some synchronized code (e.g. heavy I/O operations or infinite loop).
• A thread doesn’t get CPU’s time for execution because it has low priority as compared to other threads which have higher priority.
• Threads are waiting on a resource forever but they remain waiting forever because other threads are constantly notified instead of the hungry ones.

• When a starvation situation occurs, the program is still running but doesn’t run to completion because some threads are not executed.

• Deadlock:  All threads are blocked, the program hangs forever.

• Livelock: No threads blocked but they run into infinite loops. The program is still running but unable to make further progress.

• Starvation: Only one thread is running, and other threads are waiting forever.