CentralNotice From Wikipedia, the free encyclopedia Jump to: navigation , search Not to be confused with Promise theory . In computer science , future , promise , delay , and deferred refer to constructs used for synchronizing program execution in some concurrent programming languages . They describe an object that acts as a proxy for a result that is initially unknown, usually because the computation of its value is yet incomplete. The term promise was proposed in 1976 by Daniel P. Friedman and David Wise, [1] and Peter Hibbard called it eventual . [2] A somewhat similar concept future was introduced in 1977 in a paper by Henry Baker and Carl Hewitt . [3] The terms future , promise , delay , and deferred are often used interchangeably, although some differences in usage between future and promise are treated below. Specifically, when usage is distinguished, a future ...