The Art of Concurrency

Glossary

Adjacency matrix

A graph representation method that uses a 2D array. Each row and column corresponds to a node from the graph. If an edge exists between two nodes, a 1 value is placed at the intersection of the two nodes; otherwise, a 0 is stored to show that no edge exists.

Asynchronous

Separate execution streams that can run concurrently in any order relative to each other are asynchronous.

Atomic

A type of operation that cannot be divided into smaller components or is allowed to complete execution before the operating system swaps the executing thread out of the processor.

Barrier

A synchronization object that holds all threads until every participating thread has arrived. Upon the arrival of the last thread, all threads are released to continue execution.

Benign data race

A data race that has no adverse consequences. For example, threads may write the same value into a shared location or a flag may be updated by one thread as another is reading, leading to a little extra work for the reading thread if it does not see the updated flag value.

Bus overload

A situation in which data from I/O or memory cannot be moved at the rate of the thread or process requests. This overloading of the bus capacity will cause threads to wait for memory requests to be satisfied.

Cache prefetching

Processors may have special hardware that allows them to predict which line of cache will be needed next by an executing process. The processor can retrieve (fetch) these cache lines prior to the thread requiring ...