http://localhost:1313/tags/concurrency/ Recent content in Concurrency on UberMongoose Hugo en-us Sun, 15 Dec 2013 07:20:02 +0530 http://localhost:1313/post/pessimistic-vs-optimistic-concurrency/ Sun, 15 Dec 2013 07:20:02 +0530 http://localhost:1313/post/pessimistic-vs-optimistic-concurrency/ <p>Concurrency is when multiple jobs see incremental progress within the same time period. It may be that the concurrency is parallel where both jobs progress together at the same time or time sliced wherein parts of both jobs are done one after the other by a single processor. Whichever the case concurrency creates problems for shared resources. When there is only one job executing at a given point in time the resource can be viewed as consistent on any access. However when there is more than one job executing then care must be taken to ensure that the resource is consistent across both jobs. Consider the classic example of 2 jobs which both increment a single counter.</p>