From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: RFC: Prototype for a user threading library in Ada Date: Sat, 18 Jun 2016 13:53:00 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <58b78af5-28d8-4029-8804-598b2b63013c@googlegroups.com> <5b542d7c-e10e-4e3a-b98a-2b538bec0670@googlegroups.com> NNTP-Posting-Host: w/2xSGckQeJEFvqsQFNodA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 X-Notice: Filtered by postfilter v. 0.8.2 Xref: news.eternal-september.org comp.lang.ada:30779 Date: 2016-06-18T13:53:00+02:00 List-Id: On 2016-06-18 11:17, Hadrien Grasland wrote: > But nonblocking IO is something I want to study more during the > evolution of this library, as I think it is something which stresses the > limits of the event model I propose. Single-shot events are a good fit > when a clear notion of task completion exists, but they are less > suitable when dealing with continuous processes such as streaming IO. You could use a pulse event instead. The event is reset when all waiting tasks are released. It is not difficult to implement with protected objects using entry count attribute. > I do not want to go in the direction of reusable events, as the > amount of ways these can go wrong is all but infinite, however there has to be a better synchronization primitive for this kind of progressive evolution. One solution is to have more states than Reset/Signaled. An event can traverse a larger set of states being a small state machine. As well as transitions may be initiated not only explicitly but also through scheduling events, e.g. task release in case of the pulse event. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de