1007 2005-01-10 16:06:19 +0000 CHOICE WITH MIXTURE OF BLOCKING AND NON-BLOCKING ELEMENTS 2005-09-28 21:40:13 +0000 1 1 1 Unclassified WS Choreography Last Call Comment: Confirmed Closed unspecified PC Windows 2000 CLOSED FIXED http://lists.w3.org/Archives/Public/public-ws-chor-comments/2005Jan/0011.html P2 normal -- 1 martin.chapman martin.chapman martin.chapman oldest_to_newest 2817 0 martin.chapman 2005-01-10 16:06:19 +0000 If a choice construct has a mixture of blocking and non-blocking elements, then it is not clear how these should be processed. "If the choice has Work Units with guard conditions, the first Work Unit that matches the guard condition is selected and the other Work Units are disabled." Does this mean the 'first' with respect to time, or the first in lexical order? For example, if the choice construct has two elements, the first one blocks awaiting some information, while the second element is non-blocking: - should the choice construct evaluate the first item and then suspend until the first element has a known value. - or should the blocking element be skipped as its value cannot be determined, and therefore the second element is evaluated? However, if this second element evaluates to false, then does this mean that the choice suspends awaiting one of the blocked elements (i.e. the first element in this case) to be evaluated to true, or until no elements remain to be evaluated? The semantics of the choice construct are unclear in this situation. Regards Gary and Steve 4167 1 martin.chapman 2005-02-14 20:42:07 +0000 From meeting on 11-jan-05 http://lists.w3.org/Archives/Member/member-ws-chor/2005Jan/att-0002/2005-01- 11_WS-Chor_Notes.txt: Discussion deferred as deemed to be a technical issue. 4026 2 martin.chapman 2005-03-08 11:01:06 +0000 Discussed at feb-mar 05 F2F: http://lists.w3.org/Archives/Member/member-ws-chor/2005Mar/att- 0001/Ws_Chor_f2f__Feb-Mar_2005_-0.txt Summary: <SRT> The choice ordering structure enables specifying that at most one activity (as defined by two or more Activity-Notations) MUST be performed. Nick: don't talk about "ambiguity," it makes development difficult <SRT> Add to section: Where there is ambiguity (i.e. more than one match at the same time) for all roles involved in the matching lexical ordering is used to select a match. <SRT> Where there is more than one match lexical ordering is used to select a match. <SRT> Note for primer: We cannot solve the problem a distributed choice in which matches may occur at different participants in of different order. issue 1007 resolved with above clarification on lexical ordering. 3430 3 martin.chapman 2005-05-10 15:04:28 +0000 Steve and Gary have been informed of the group's decision [1] and we are awaiting confirmation. Category changed to LCC: Closed. [1] http://lists.w3.org/Archives/Public/public-ws-chor- comments/2005May/0010.html 3058 4 gritzinger 2005-05-25 19:10:00 +0000 In 2.5.1.3 Choice instated the sentence:‘Where there is more than one match lexical ordering is used to select a match.’ 6560 5 martin.chapman 2005-09-28 21:40:13 +0000 cross checked and closed confirmed