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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,97ae587931c0f702,start X-Google-Attributes: gid103376,public From: kmradke@inav.net (Kevin Radke) Subject: Ada Task priorities Date: 1997/01/26 Message-ID: #1/1 X-Deja-AN: 212378500 organization: KrustyLand Amusement Park newsgroups: comp.lang.ada Date: 1997-01-26T00:00:00+00:00 List-Id: Hello, Can one guarantee how tasks at different priority levels will be executed with respect to eachother? (Speaking in both ada83 and ada95 terms...) I.E. the following scenario: task a at the highest priority level task b at a priority level between the highest and lowest levels task c at the lowest priority level Can one guarantee that if all 3 tasks are eligible for execution at the same time, that task a will finish it's work before task b begins to run, and task c will only run after both tasks a and b finish? (Assuming no tasks rendezvous with other tasks during this time?) I suppose even OS calls would make this highly platform dependent. The ada83 RM seems to be pretty explicit about requiring "The highest priority eligible task must be executing at any given time", but the ada95 RM seems less verbose about this. Even annex D doesn't seem to require this. (Unless I missed something obvious, which I probably have...) My personal opinion is that using assumptions about priorities like this is just asking for trouble, but I thought I would get other people's opinions on this... Thanks! Kevin -- /\/\Under Construction/\/\ kmradke@inav.net