Deadlock, Starvation, and Livelock

Know the Vocabulary

This lesson uses the terms below many times. Read them once now, and come back here when a later section needs one.

• Lock: A tool that lets only one thread at a time use some shared data. A thread takes the lock before it uses the data and releases it after.
• Blocked: The state of a thread that is waiting for a lock that another thread holds. A blocked thread uses no CPU time.
• Deadlock: A state where two or more threads each wait for a lock that another one of them holds, so none of them can ever continue.
• Circular wait: A closed loop of waiting