!standard 9.5(9) 11-05-11 AI05-0215-1/09 !standard 9.5.4(3) !standard 9.5.4(5) !standard E.2.2(14) !class Amendment 11-04-28 !status Amendment 2012 11-05-11 !status ARG Approved (by Letter Ballot) 9-1-1 11-05-16 !status work item 10-04-30 !status ARG Approved 6-0-2 11-04-07 !status work item 10-06-12 !status received 10-03-26 !priority Low !difficulty Easy !qualifier Omission !subject Pragma Implemented should be an aspect, renamed, and better defined !summary The aspect Synchronization is introduced as the proper way of specifying how a synchronized interface operation must be implemented (replacing the pragma Implemented of AI05-0030-2). !question (1) I don't see any rule that says that you can't write two Implemented pragmas for the same subprogram. (If the Standard said that Implemented were a representation pragma, as it does for No_Return, this would follow automatically; but it doesn't say that anywhere.) (2) The pragma doesn't make sense unless Implemented pragmas explicitly specified for subprograms apply to inherited subprograms. But there is no wording to that effect in the Standard. 3.9.2(10) says explicitly that the convention was inherited for some inherited subprograms, so similar wording is needed for Implemented (and No_Return as well). (3) 9.5.4(3/3) says: "The procedure_or_entry_name of a requeue_statement shall resolve to denote a procedure or an entry (the requeue target) that either has no parameters, or that has a profile that is type conformant (see 6.3.1) with the profile of the innermost enclosing entry_body or accept_statement." But this makes no sense for a procedure; the procedure has to have a first parameter that is of a synchronized type. So there can't be a procedure with no parameters here. Moreover, because of this first parameter, the profile can't conform with the enclosing entry. Probably it is the *prefixed view profile* that has to conform. Similar problems arise in 9.5.4(5/3). (4) We're changing many pragmas to be primarily aspects; it seems that pragma Implemented should be an aspect as well. !recommendation (See Summary.) !wording Delete 9.5 (10/3-11/3). Modify 9.5 (12/3) as follows: Synchronization_Kind ::= By_Entry | By_Protected_Procedure | Optional Modify 9.5(13/3 - 16/3) as follows: For the declaration of a primitive procedure of a synchronized tagged type the following language-defined representation aspect may be specified with an aspect_specification (see 13.3.1): Synchronization. If specified, the aspect definition shall be a Synchronization_Kind. The Synchronization_Kind By_Protected_Procedure shall not be applied to a primitive procedure of a task interface. A procedure for which the specified Synchronization_Kind is By_Entry shall be implemented by an entry. A procedure for which the specified Synchronization_Kind is By_Protected_Procedure shall be implemented by a protected procedure. A procedure for which the specified Synchronization_Kind is Optional may be implemented by an entry or by a procedure (including a protected procedure). If a primitive procedure overrides an inherited operation for which the Synchronization aspect has been specified to be By_Entry or By_Protected_Procedure, then any specification of the aspect Synchronization applied to the overriding operation shall have the same Synchronization_Kind. Modify 9.5(18/3) as follows: [A pragma Implemented is said to *apply* to the procedure denoted by its *procedure_*local_name.] {Inherited subprograms inherit the Synchronization aspect, if any, from the corresponding subprogram of the parent or progenitor type.} If an overriding operation does not have a [pragma] {directly specified} Synchronization {aspect} then [any pragma Implemented applying to] {the Synchronization aspect of} the inherited operation [applies to] {is inherited by} the overriding operation. Modify 9.5.4(3/3) as follows: The *procedure_or_entry_*name of a requeue_statement shall resolve to denote a procedure or an entry (the requeue target){. The profile of the entry, or the profile or prefixed profile of the procedure, shall} [that] either [has] {have} no parameters, or [that has a profile that is] {be} type conformant (see 6.3.1) with the profile of the innermost enclosing entry_body or accept_statement. Modify 9.5.4(5/3) as follows: If the requeue target has parameters, then its {(prefixed)} profile shall be subtype conformant with the profile of the innermost enclosing callable construct. Modify 9.5.4(5.1/3) as follows: If the target is a procedure, the name shall denote a renaming of an entry, or shall denote {a view or} a prefixed view of a primitive subprogram of a synchronized interface, where the first parameter of the unprefixed view of the primitive subprogram shall be a controlling parameter, and [an Implemented pragma] {the Synchronization aspect shall be specified} with [implementation_kind]{Synchronization_Kind} By_Entry [shall apply to] {for} the primitive subprogram. Modify E.2.2(14.1/3) [from AI05-0060-1]: * The corresponding specific type shall not have a primitive procedure {with the Synchronization aspect specified}[to which a pragma Implemented applies] unless the [implementation_kind]{synchronization_kind} [of the pragma] is {Optional}[By_Any]; !discussion !corrigendum 9.5(9) @dinsa Any call on a protected procedure or entry of a target protected object is defined to be an update to the object, as is a requeue on such an entry. @dinss @s8<@i> @xcode< @fa@ft@fa< | >@ft@fa< | >@ft> @s8<@i> For the declaration of a primitive procedure of a synchronized tagged type the following language-defined representation aspect may be specified with an @fa (see 13.3.1): @xhang<@xterm If specified, the aspect definition shall be a @fa.> Inherited subprograms inherit the Synchronization aspect, if any, from the corresponding subprogram of the parent or progenitor type. If an overriding operation does not have a directly specified Synchronization aspect then the Synchronization aspect of the inherited operation is inherited by the overriding operation. @s8<@i> The @fa By_Protected_Procedure shall not be applied to a primitive procedure of a task interface. A procedure for which the specified @fa is By_Entry shall be implemented by an entry. A procedure for which the specified @fa is By_Protected_Procedure shall be implemented by a protected procedure. A procedure for which the specified @fa is Optional may be implemented by an entry or by a procedure (including a protected procedure). If a primitive procedure overrides an inherited operation for which the Synchronization aspect has been specified to be By_Entry or By_Protected_Procedure, then any specification of the aspect Synchronization applied to the overriding operation shall have the same @fa. In addition to the places where Legality Rules normally apply (see 12.3), these rules apply also in the private part of an instance of a generic unit. NOTE @s9<18 The @fa By_Protected_Procedure implies that the operation will not block.> !corrigendum 9.5.4(3) @drepl The @i@fa of a @fa shall resolve to denote an entry (the @i) that either has no parameters, or that has a profile that is type conformant (see 6.3.1) with the profile of the innermost enclosing @fa or @fa. @dby The @i@fa of a @fa shall resolve to denote a procedure or an entry (the @i). The profile of the entry, or the profile or prefixed profile of the procedure, shall either have no parameters, or be type conformant (see 6.3.1) with the profile of the innermost enclosing @fa or @fa. !corrigendum 9.5.4(5) @drepl If the target entry has parameters, then its profile shall be subtype conformant with the profile of the innermost enclosing callable construct. @dby If the requeue target has parameters, then its (prefixed) profile shall be subtype conformant with the profile of the innermost enclosing callable construct. If the target is a procedure, the name shall denote a renaming of an entry, or shall denote a view or a prefixed view of a primitive subprogram of a synchronized interface, where the first parameter of the unprefixed view of the primitive subprogram shall be a controlling parameter, and the Synchronization aspect shall be specified with @fa By_Entry for the primitive subprogram. !corrigendum E.2.2(14/2) @dinsa @xbullet @dinst @xbullet is Optional;> !ACATS Test ACATS tests are needed as explained in AI05-0030-2. !appendix !topic Missing rules in Implemented definition? !reference 9.5(10-18) !from Adam Beneschan 10-03-26 !discussion (1) I don't see any rule that says that you can't write two Implemented pragmas for the same subprogram. (If the RM said that Implemented were a representation pragma, as it does for No_Return, I think this would follow automatically; but I don't think it says that anywhere.) (2) The pragma doesn't make sense unless Implemented pragmas explicitly specified for subprograms apply to inherited subprograms. However, I haven't found anywhere in the RM that says that pragmas that apply to subprograms automatically apply to inherited subprograms. Nothing in 3.4 (which is the main place subprogram inheritance is discussed) says anything about subprograms inheriting anything other than the name and profile. In 3.9.2(10), it appears that it was deemed necessary to say explicitly that the convention was inherited for some inherited subprograms. So I think that somewhere, either 9.5 should say that if Implemented applies to a subprogram it applies to an inherited subprogram (and 6.5.1 needs to say something similar about No_Return), or there needs to be a more general statement about what properties or characteristics are inherited by an inherited subprogram. **************************************************************** !topic Errors in AI05-0030-2 !reference 9.5.4 !from Adam Beneschan 10-03-30 !discussion There appear to be some errors in the changes made for AI05-0030-2. 9.5.4(3/3): "The procedure_or_entry_name of a requeue_statement shall resolve to denote a procedure or an entry (the requeue target) that either has no parameters, or that has a profile that is type conformant (see 6.3.1) with the profile of the innermost enclosing entry_body or accept_statement." First of all, I note that in the online version (www.adaic.org/standards/1zaarm/html/AA-9-5-4.html), the paragraph didn't get updated correctly; it says "denote an entry" rather than "denote a procedure or entry" which of course defeats the whole purpose. But this error isn't worth changing since the whole paragraph is wrong anyway. If the procedure_or_entry_name denotes a procedure, doesn't it have to denote a procedure whose first parameter is a synchronized interface type (or access-to-)? If that's the case, than it certainly can't resolve to a procedure with no parameters. Also, if it's a procedure, its profile can't be type conformant with that of the enclosing entry; rather, isn't it the procedure's *prefixed view profile* that has to be type conformant? So I think this just needs to be redone. I'm not sure exactly how, since I don't know what you want to put in a Name Resolution Rule. 9.5.4(5/3) has the same problem: "If the requeue target has parameters, then its profile shall be subtype conformant with the profile of then innermost enclosing callable construct"---again, if the requeue target is a procedure, the prefixed view profile is what has to be subtype conformant. Also, if the requeue target is a procedure with *one* parameter, then this rule wouldn't apply---the one parameter is the controlling synchronized interface parameter, but otherwise it should be treated like a parameterless entry. So maybe this needs to be something like If the requeue target is an entry that has parameters, then its profile shall be subtype conformant with the profile of the innermost enclosing callable construct. If the requeue target is a prefixed view of primitive subprogram [procedure] of a synchronized interface, and if the subprogram has more than one parameter, then its prefixed view profile shall be subtype conformant with the profile of the innermost enclosing callable construct. **************************************************************** From: Bob Duff Sent: Sunday, January 23, 2011 2:35 PM ... > * AI05-0215-1 Suggest a better aspect name than "Implemented" [Nov. > phone meeting] I don't see anything about this in those minutes. But anyway, here's my suggested name changes (for the pragma and it allowed arguments): Implemented --> Synchronized_Implementation By_Entry --> Entry By_Protected_Procedure --> Protected_Procedure By_Any --> Any Or maybe just change the pragma name. **************************************************************** From: John Barnes Sent: Sunday, January 23, 2011 4:15 PM Seems preferable as it is to me. **************************************************************** From: Robert Dewar Sent: Sunday, January 23, 2011 5:37 PM > Implemented --> Synchronized_Implementation I find this much too long **************************************************************** From: Bob Duff Sent: Sunday, January 23, 2011 5:46 PM Do you have a better idea? Does anybody remember why we wanted to change this name? I think it's because (1) "Implemented" is way to general a term for what this thing does, and (2) it doesn't read well as an aspect. But I don't really remember the discussion. And I'm still ambivalent about shoe-horning everything under the Sun into "aspect" syntax. The minutes don't clue me in. Anyway, I don't buy "too long", because it's rarely used. It will increase the total size of all Ada programs world wide by perhaps 0.000_001%". ;-) **************************************************************** From: Robert Dewar Sent: Sunday, January 23, 2011 5:52 PM > Does anybody remember why we wanted to change this name? > I think it's because (1) "Implemented" is way to general a term for > what this thing does, and (2) it doesn't read well as an aspect. But > I don't really remember the discussion. > And I'm still ambivalent about shoe-horning everything under the Sun > into "aspect" syntax. The minutes don't clue me in. I think the current proposal is better than your proposed substitute. > Anyway, I don't buy "too long", because it's rarely used. > It will increase the total size of all Ada programs world wide by > perhaps 0.000_001%". ;-) The fact that a nasty long name is not going to be used often is not a good enough justification for me. **************************************************************** From: Randy Brukardt Sent: Monday, January 24, 2011 9:36 PM ... > Does anybody remember why we wanted to change this name? My recollection is that you were the one that wanted to change it, so I would have hoped you remembered why. ;-) > I think it's because (1) "Implemented" is way to general a term for > what this thing does, and (2) it doesn't read well as an aspect. But > I don't really remember the discussion. > And I'm still ambivalent about shoe-horning everything under the Sun > into "aspect" syntax. The minutes don't clue me in. I think that sounds about right. "Implemented" doesn't seem to indicate at all what it is about. It's really "the overriding or implemented-by routine must be of this kind". "Implemented by" only is true for task and protected operations, and this definition is wider than that anyway. I think we were hoping that you would have a wonderful idea that's nice and short and descriptive. Part of the problem is that *Ada* doesn't have such a term, so it's asking a lot for something meaningful. Perhaps someone will have a better idea from these musings. **************************************************************** From: Brad Moore Sent: Tuesday, January 25, 2011 8:33 AM > Perhaps someone will have a better idea from these musings. How about just Synchronized? The word Implemented doesn't really add anything. Also, this allows us to get rid of By_Any. If the pragma doesn't have an argument, that would be the By_Any case. Implemented --> Synchronized By_Entry --> Entry By_Protected_Procedure --> Protected_Procedure By_Any --> **************************************************************** From: Bob Duff Sent: Tuesday, January 25, 2011 8:45 AM > How about just Synchronized? The word Implemented doesn't really add > anything. I like it. > Also, this allows us to get rid of By_Any. If the pragma doesn't have > an argument, that would be the By_Any case. I'm not sure about that. It's not intuitively obvious that "pragma Synchronized;" means "by-any". > Implemented --> Synchronized > By_Entry --> Entry > By_Protected_Procedure --> Protected_Procedure Agreed. > By_Any --> I think I prefer "By_Any --> Any". OTOH, I'd be happy to keep the "By_" prefixes, if folks like them. The main thing is to rename the pragma/aspect itself. **************************************************************** From: Tucker Taft Sent: Tuesday, January 25, 2011 8:49 AM Unfortunately, both "synchronized" and "entry" are reserved words. Perhaps: Is_Synchronized => By_Entry Is_Synchronized => By_Protected_Procedure Is_Synchronized [=> True] Is_Synchronized => False **************************************************************** From: Bob Duff Sent: Tuesday, January 25, 2011 8:59 AM > Unfortunately, both "synchronized" and "entry" are reserved words. I was thinking that's OK for pragmas. But now I realize that if you want to make it an aspect, reserved words are a no-no. > Perhaps: > > Is_Synchronized => By_Entry > Is_Synchronized => By_Protected_Procedure Is_Synchronized [=> True] > Is_Synchronized => False Looks good. **************************************************************** From: Brad Moore Sent: Tuesday, January 25, 2011 9:42 AM I suppose "synchronous" could be another alternative, that isn't a reserved word. If that were the case, is it just the aspect name that causes a problem? Or would the aspect qualifiers also present a problem if they conflict with reserved words. ie pragma Synchronous (Entry); pragma Synchronous (Protected_Procedure); Synchronous => Entry Synchronous => Protected_Procedure Synchronous [=> True] Syncrhonous => False; In any case, I'm not sure which I like better. They both look good to me, and an improvement over the pragma Implemented. **************************************************************** From: John Barnes Sent: Tuesday, January 25, 2011 11:23 AM I am happy with Is_Synchronized and keeping By. I much prefer By_Any to True or False. Having them all start By_ has a nice rhythm to it. By_Whatever, By_Any_Old_How, By_George... **************************************************************** From: John Barnes Sent: Tuesday, January 25, 2011 2:02 PM I should have added By_Hook_Or_By_Crook. **************************************************************** From: Edmond Schonberg Sent: Tuesday, January 25, 2011 3:36 PM Not to mention By_Mistake and By_Pure_Luck. **************************************************************** From: Edmond Schonberg Sent: Tuesday, March 15, 2011 2:31 PM > AI05-0215-1: (see minutes of meeting #42) There is no mention of 0215 in the October minutes. Bob had the same reaction in January, and then went on to propose different values for the corresponding aspect. Given that this is a correction of another AI, should we just withdraw AI05-030 (even though WG9 approved) and rewrite it without the Implemented pragma (no one uses it yet) and with the new Aspect Implemented_By? **************************************************************** From: Randy Brukardt Sent: Tuesday, March 15, 2011 2:50 PM > There is no mention of 0215 in the October minutes. Sorry, it was the November phone meeting. But that doesn't say much: Ed will take this one, and convert it to an aspect, removing the pragma. [Editor's note: change the subject when this is done, and add a question to this effect.] Is the name "Implemented" good? We don't have a better idea, and typical formatting puts the aspect by itself on the left. Bob thinks the name is too general; he will take this off-line and try to come with a better name. "Implemented_By_Entry" as a boolean aspect is a thought. "Implemented_By_Entry => False" is really "maybe", not "no", so that isn't perfect. We'll let Bob think about this. [End of November minutes.] > Bob had > the same reaction in January, and then went on to propose different > values for the corresponding aspect. That was Bob responding to the action item above. > Given that > this is a correction of another AI, should we just withdraw AI05-030 > (even though WG9 approved) and rewrite it without the Implemented > pragma (no one uses it yet) and with the new Aspect Implemented_By? I don't think we want to withdraw it completely, since quite a bit of it will be unchanged. (Certainly all of the stuff about Requeue has no reason to change.) So I think you should just write up this AI saying that it is replacing paragraphs whatever to whenever. But we're not going to "withdraw" a WG 9 approved AI (even if this one ends up rewriting 90% of the paragraphs -- which I doubt). **************************************************************** From: Bob Duff Sent: Tuesday, March 15, 2011 3:51 PM > > Bob had > > the same reaction in January, and then went on to propose different > > values for the corresponding aspect. > > That was Bob responding to the action item above. I still pretty-much hate the name Implemented (or Implemented_By), for the reasons I already mentioned. Tucker's suggestion ("Tuesday, January 25, 2011 8:49 AM", in the !appendix) seems perfect to me: Is_Synchronized => By_Entry Is_Synchronized => By_Protected_Procedure Is_Synchronized [=> True] Is_Synchronized => False **************************************************************** From: Edmond Schonberg Sent: Tuesday, March 15, 2011 4:20 PM I agree with this choice, that should be the name and the legal values of the new aspect. **************************************************************** From: Randy Brukardt Sent: Tuesday, March 15, 2011 4:31 PM Fine by me, and since you are writing it up, you get to make the recommended choice anyway. If someone wants a choice other than the one you make, *they* can write it up. That should minimize the alternatives proposed. ;-) **************************************************************** From: Bob Duff Sent: Tuesday, March 15, 2011 4:41 PM > > Is_Synchronized => By_Entry > > Is_Synchronized => By_Protected_Procedure Is_Synchronized [=> True] > > Is_Synchronized => False > > I agree with this choice, that should be the name and the legal values > of the new aspect. Note that True and False here, are not values of type Boolean. They are "identifiers specific to an aspect". That's not a problem, just a language-lawyerly oddity. It means you can't say: Is_Synchronized => Boolean'(False) Is_Synchronized => Standard.False X : constant Boolean := False; ... Is_Synchronized => X If you don't like that, I suppose you could define an enumeration type (By_Entry, By_Protected_Procedure, True, False), or perhaps (By_Entry, By_Protected_Procedure, Yes, No). But I wouldn't bother with that. **************************************************************** From: Edmond Schonberg Sent: Wednesday, March 16, 2011 3:55 PM Here is an aspect-centric version of this AI. The new aspect is Is_Synchronized, and the aspect definition is a synchronization_kind: Synchronization_Kind ::= By_Entry | By_Protected_Procedure | By_Any. I did not see the need to have an additional value to specify a default, given the stated inheritance rules. I guess Bob will move the skeleton of the previous version of the AI to annex J. [This is version /02 of the AI - Editor.] **************************************************************** From: Tucker Taft Sent: Wednesday, March 16, 2011 4:06 PM Can't say I love "Is_Synchronized => By_Any" Doesn't make a whole lot of sense to me. "Yes" or "True" would read better, IMHO. **************************************************************** From: Edmond Schonberg Sent: Wednesday, March 16, 2011 4:14 PM "True" seems confusing because this is not a boolean aspect. I guess Is_Synchronized => Yes is acceptable, to indicate that some subsequent overriding operation will be a legal target of a requeue operation. **************************************************************** From: Bob Duff Sent: Wednesday, March 16, 2011 5:01 PM > I did not see the need to have an additional value to specify a > default, = given the stated inheritance rules. OK. > I guess Bob will move the skeleton of the previous version of the AI > to = annex J. I think that's Randy's job. **************************************************************** From: Randy Brukardt Sent: Wednesday, March 16, 2011 9:46 PM > I guess Bob will move the skeleton of the previous version of the AI > to annex J. I thought that we were not even going to define a pragma for this one (unlike CPU). Pragmas are nasty for subprograms, and these are subprograms. So no need to put anything in Annex J. **************************************************************** From: Randy Brukardt Sent: Wednesday, March 16, 2011 9:53 PM > Can't say I love "Is_Synchronized => By_Any" > Doesn't make a whole lot of sense to me. > "Yes" or "True" would read better, IMHO. Except that it really means that it is not necessarily synchronized (it can be a normal subprogram, which is not synchronized by any imagination), so it is more like "Maybe_Not". Is_Synchronized => Maybe_Not Perfect. ;-) Is_Synchronized => Probably_Not Is_Synchronized => Hardly_Ever Is_Synchronized => Not_Specified (but specifying something to be Not_Specified seems like a tautology :-) Is_Synchronized => Not_Required Is_Synchronized => Not_Necessarily_Synchronized Fill in your own ideas here. **************************************************************** From: Randy Brukardt Sent: Wednesday, March 16, 2011 10:14 PM > Here is an aspect-centric version of this AI. Your version seem to have lost the revised 9.5(18/3) that defined the inheritance of the aspects. (This was part of the fixes of this AI, not something that previously existed - there are no rules in the Standard that described inheritance for aspects of subprograms - of course, Tucker might be writing those as I write this.) Anyway, I put it back, pending whatever Tucker does in 13.1. Modify 9.5(18/3): [A pragma Implemented is said to *apply* to the procedure denoted by its *procedure_*local_name.] {Inherited subprograms inherit the Implemented aspect, if any, from the corresponding subprogram of the parent or progenitor type.} If an overriding operation does not have a [pragma] {directly specified} Implemented {aspect} then [any pragma Implemented applying to] {Implemented aspect of} the inherited operation [applies to] {is inherited by} the overriding operation. The last paragraph doesn't mark the changes properly (since "implementation-kind" and "Implemented" were changed without markings): Modify 9.5.4(5.1/3): If the target is a procedure, the name shall denote a rename of an entry, or shall denote {a view or} a prefixed view of a primitive subprogram of a synchronized interface, where the first parameter of the unprefixed view of the primitive subprogram shall be a controlling parameter, and [an Implemented pragma] {the Is_Synchronized aspect shall be specified} with [implementation_kind]{Synchronization_Kind} By_Entry [shall apply to] {for} the primitive subprogram. I've corrected the AI with these changes. **************************************************************** From: Edmond Schonberg Sent: Wednesday, March 16, 2011 10:20 PM > Your version seem to have lost the revised 9.5(18/3) that defined the > inheritance of the aspects. (This was part of the fixes of this AI, > not something that previously existed - there are no rules in the > Standard that described inheritance for aspects of subprograms I thought (naively no doubt) that the rules for pre- and post-conditions are precisely inheritance rules for aspects of subprograms. **************************************************************** From: Randy Brukardt Sent: Wednesday, March 16, 2011 10:33 PM ... > > Your version seem to have lost the revised 9.5(18/3) that defined > > the inheritance of the aspects. (This was part of the fixes of this > > AI, not something that previously existed - there are no rules in > > the Standard that described inheritance for aspects of subprograms > > I thought (naively no doubt) that the rules for pre- and > post-conditions are precisely inheritance rules for aspects of > subprograms. I don't think Pre or Post are inherited at all. There is a rule for Pre'Class and Post'Class (13.3.2(10/3)) that specifically defines that they "apply" to descendants, but formally they aren't inherited either (which is why you can give a new one for them on the descendant). So that isn't much help. ;-) **************************************************************** From: Jean-Pierre Rosen Sent: Thursday, March 17, 2011 4:13 AM > Fill in your own ideas here. Is_Synchronized => Optional **************************************************************** From: Gary Dismukes Sent: Wednesday, April 6, 2011 7:10 PM This is a wording nit for AI05-0215. In the !corrigendum, the third instance of "Is_Synchronized aspect" should be preceded by 'the': Modify 9.5(18/3) as follows: [A pragma Implemented is said to *apply* to the procedure denoted by its *procedure_*local_name.] {Inherited subprograms inherit the Is_Synchronized aspect, if any, from the corresponding subprogram of the parent or progenitor type.} If an overriding operation does not have a [pragma] {directly specified} Is_Synchronized {aspect} then [any pragma Implemented applying to] {Is_Synchronized aspect of} the inherited ^^^^^^^^^^^^^^^^^^^^^^^^^^^ {Is_Synchronized aspect of} => {the Is_Synchronized aspect of} operation [applies to] {is inherited by} the overriding operation. And I may as well mention a really small nit wrt the !corrigendum wording for 9.5.4(5.1/3): Modify 9.5.4(5.1/3) as follows: If the target is a procedure, the name shall denote a rename of an entry,... I suggest changing "a rename of" to "a renaming of". While there are a few places in the RM that use the wording "rename of", the majority say "renaming of", and personally I think the latter sounds better. I suppose all the various instances of this wording should be made consistent. (I'll understand if you choose to simply ignore this suggestion. :) **************************************************************** From: John Barnes Sent: Thursday, April 7, 2011 6:20 AM In the following note some typos Modify 9.5(13/3 - 16/3) as follows: For the declaration of a primitive procedure of a synchronized tagged type the following language-defined representation aspect may be specified with an aspect_specification: Is_Synchronized. If specified, the aspect definition shall be a Synchronization_Kind. The Synchronization_Kind By_Protected_Procedure shall not be applied to a primitive procedure of a task interface. A procedure for which the specified Synchronization_Kind is By_Entry shall be implemented by [a] an entry. A procedure for which the specified Synchronization_Kind is [as] By_Protected_Procedure shall be implemented by a protected procedure. If a primitive procedure overrides an inherited operation for which the Is_Synchronized aspect has been specified, then any specification of the aspect Is_Synchronized applied to the overriding operation shall have the same Synchronization_Kind, or the inherited Synchronization_Kind shall be Optional. For completeness in the para starting "A procedure" in the above. I would add something about the poor lonely Optional. eg A procedure for which the the specified Synchronization_Kind is Optional can be implemented by an entry or by a procedure (including a protected procedure). Maybe it is somthing to do with the battle of Agincourt but I don't like Optional but much prefer By_Any. It just has to start By_ **************************************************************** From: Randy Brukardt Sent: Thursday, April 7, 2011 9:20 PM ... > Modify 9.5(13/3 - 16/3) as follows: ... > A procedure for which the specified Synchronization_Kind is By_Entry shall > be implemented by [a] an entry. A procedure for which the > specified Synchronization_Kind is [as] By_Protected_Procedure shall be > implemented by a protected procedure. ... > For completeness in the para starting "A procedure" in the above. I > would add something about the poor lonely Optional. eg > > A procedure for which the the specified Synchronization_Kind is > Optional can be implemented by an entry or by a procedure (including a > protected procedure). This is a fine idea, but "can" is not allowed in International Standards (by the drafting rules). We have to use "may" here. We can use "may", but may not use "can". Similarly, we must use "shall", we shall not use "must". But we cannot use "may not", and we may not use "cannot". Easy to remember, right? ;-) **************************************************************** From: Tucker Taft Sent: Wednesday, April 20, 2011 3:27 PM [This was a comment on the editorial review of part of the Rationale for Ada 2012. - Editor] > Rant 2: > > I don't disagree, but no one (including you) has had a better idea. > There is still time. > > Is_Synchronized => Optional > > could be: > > Is_Synchronized => Not_Required Is_Synchronized => Perhaps_Not Is_Synchronized => Who_Cares Is_Synchronized => Who_Wants_To_Know > > Another possibility is to dump By_ altogether: > > Is_Synchronized => Entry -- Prefer to avoid this, as "entry" is > reserved. > Is_Synchronized => Use_Entry > Is_Synchronized => Requires_Entry. Or dump "Is_" in favor of: with Synchronization => [By_Entry | By_Protected_Procedure | Not_Specified ] **************************************************************** From: John Barnes Sent: Thursday, April 21, 2011 8:24 AM Personally I (John) was very happy with the old Implemented =>.....| By_Any ... > Or dump "Is_" in favor of: > > with Synchronization => [By_Entry | By_Protected_Procedure | Not_Specified ] > That is certainly an improvement. I will think about it over Easter. **************************************************************** From: Randy Brukardt Sent: Thursday, April 21, 2011 9:52 AM > Personally I (John) was very happy with the old Implemented =>.....| > By_Any "By_Any" is too ambiguous to be a good name. It is not "any" synchronized operation, it is any operation, synchronized or not. If you really want to use "By_Any", then we have to get rid of "Is_Synchronized" and use something much more generic. "Routine_Must_Be_Implemented_By" or something like that. (And that wasn't liked either.) **************************************************************** From: Tucker Taft Sent: Monday, May 2, 2011 9:44 PM [Part of a message appropriate to this AI.] AI05-0215-1/08 Pragma Implemented should be an aspect, renamed, and better defined [The class of this AI was wrong; it modifies an Amendment AI, so it also has to be Amendment. Otherwise, it is unchanged.] Approve ___X___ Disapprove ______ Abstain _______ Comments: I prefer the aspect name "Synchronization" to "Is_Synchronized". I think "Synchronization => Optional" is significantly nicer than "Is_Synchronized => Optional" and "Synchronization => By_Entry/By_Protected_Procedure" also reads well. Finally, it seems more natural for the aspect to be "Synchronization" if the corresponding type is "Synchronization_Kind." This paragraph is slightly weird: If a primitive procedure overrides an inherited operation for which the Is_Synchronized aspect has been specified, then any specification of the aspect Is_Synchronized applied to the overriding operation shall have the same Synchronization_Kind, or the inherited Synchronization_Kind shall be Optional. It seems odd to create a requirement on the inherited Synchronization_Kind, since that is already determined at the point where the operation is being overridden. To me, it would make more sense to phrase this as follows: If a primitive procedure overrides an inherited operation for which the Synchronization aspect has been specified to be By_Entry or By_Protected_Procedure, then any specification of the aspect Synchronization applied to the overriding operation shall have the same Synchronization_Kind. **************************************************************** From: Randy Brukardt Sent: Monday, May 2, 2011 10:32 PM [Part of a message appropriate to this AI.] ... > AI05-0215-1/08 Pragma Implemented should be an aspect, renamed, and > better defined > [The class of this AI was wrong; it modifies an Amendment AI, so > it also has to be Amendment. > Otherwise, it is unchanged.] > Approve ___X___ Disapprove ______ Abstain _______ > Comments: I prefer the aspect name "Synchronization" to > "Is_Synchronized". I think "Synchronization => Optional" is > significantly nicer than "Is_Synchronized => Optional" and > "Synchronization => By_Entry/By_Protected_Procedure" also > reads well. Finally, it seems more natural for the aspect to > be "Synchronization" if the corresponding type is "Synchronization_Kind." Humm, anyone else have a thought on this one? > This paragraph is slightly weird: > If a primitive procedure overrides an inherited operation for which the > Is_Synchronized aspect has been specified, then any specification of the > aspect Is_Synchronized applied to the overriding operation shall have the > same Synchronization_Kind, or the inherited Synchronization_Kind shall be > Optional. > It seems odd to create a requirement on the inherited Synchronization_Kind, since > that is already determined at the point where the operation is being overridden. > To me, it would make more sense to phrase this as follows: > If a primitive procedure overrides an inherited operation for which the > Synchronization aspect has been specified to be By_Entry or > By_Protected_Procedure, then any specification of the aspect Synchronization > applied to the overriding operation shall have the same Synchronization_Kind. OK by me. **************************************************************** From: Tucker Taft Sent: Tuesday, May 3, 2011 7:45 AM [Part of a message appropriate to this AI.] ... > Humm, anyone else have a thought on this one? John Barnes already gave this idea the thumbs up, several weeks ago. **************************************************************** From: John Barnes Sent: Tuesday, May 3, 2011 11:16 AM I strongly prefer Synchronization. But instead of Optional we could have Is_Optional or Not_Specified (the latter you (Tuck) suggested earlier. I did promise to chew over this over Easter. However my mind was on other things like the old lady I bashed in a car park in Shropshire (actually I only bashed her motor) and the fact that my beloved wife left her bag in Wales when we travelled to the Peak district and this meant that a courier had to spend a happy few hours driving around to get it. **************************************************************** From: Randy Brukardt Sent: Tuesday, May 3, 2011 5:43 PM ... > I did promise to chew over this over Easter. However my mind was on > other things ... Uh-huh. Anyway, I would hope that we are all done chewing from Easter. (Else that was one tough ham served for Easter dinner. ;-) What this problem requires is bold decision-making. (OK, not from this group. :-) I'll set up another one of my famous straw polls to gauge the thinking on this one. **************************************************************** From: Randy Brukardt Sent: Tuesday, May 3, 2011 6:00 PM (Sorry about the cryptic subject; it is hard to write a subject for this message without biasing the results.) We've previously discussed (without conclusion) possible names for the aspect defined by AI05-0030-2 and AI05-0215-1. It originally was "Implemented", and it now has changed into "Is_Synchronized". Part of the problem is that most of the best names turn out to be reserved words. We're also still unclear on the best name for the default state of this aspect (note that this name will usually not appear in program text; it is primarily a wording aid). Note that the other states are named By_Entry and By_Protected_Procedure, so the aspect name should work with those names (those will appear in program text). So I am asking for a quick straw poll on this issue. If needed, AI05-0215-1 will be modified with the result of this poll. I've gathered up the most interesting ideas floated so far: Please rank the top three of the following solutions from 1 (preferred) to 3 (least preferred): ______ The aspect is named Is_Synchronized and the default state is Optional [this is the current definition] ______ The aspect is named Is_Synchronized and the default state is Not_Required ______ The aspect is named Is_Synchronized and the default state is Not_Specified ______ The aspect is named Is_Synchronized and the default state is Perhaps_Not ______ The aspect is named Is_Synchronized and the default state is Who_Cares ______ The aspect is named Is_Synchronized and the default state is By_Any ______ The aspect is named Synchronization and the default state is Optional ______ The aspect is named Synchronization and the default state is Not_Specified ______ The aspect is named Synchronization and the default state is Not_Required ______ The aspect is named _______________ and the default state is ________________ [Editor's note: I suspect that some of these were suggested in jest, but there is no indication of that in the messages, so I've put them all here for voting.] **************************************************************** From: Randy Brukardt Sent: Tuesday, May 3, 2011 6:02 PM Here's my ballot: ... > Please rank the top three of the following solutions from 1 > (preferred) to 3 (least > preferred): > > > ______ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ___3___ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > ___2___ The aspect is named Synchronization and the default state is > Optional > > ______ The aspect is named Synchronization and the default state is > Not_Specified > > ___1___ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ **************************************************************** From: Bob Duff Sent: Tuesday, May 3, 2011 6:28 PM Here are my votes: > __3___ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ______ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > __1___ The aspect is named Synchronization and the default state is > Optional > > ______ The aspect is named Synchronization and the default state is > Not_Specified > > __2___ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ **************************************************************** From: Tucker Taft Sent: Tuesday, May 3, 2011 6:33 PM > Please rank the top three of the following solutions from 1 > (preferred) to 3 (least > preferred): > > > ______ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ______ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > ___2___ The aspect is named Synchronization and the default state is > Optional > > ____1__ The aspect is named Synchronization and the default state is > Not_Specified > > ___3___ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ **************************************************************** From: Robert Dewar Sent: Tuesday, May 3, 2011 10:33 PM > Please rank the top three of the following solutions from 1 > (preferred) to 3 (least > preferred): > > > __`____ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ______ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > ______ The aspect is named Synchronization and the default state is > Optional > > ______ The aspect is named Synchronization and the default state is > Not_Specified > > ______ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ > I don't have a 2 and a 3, because I don't care, my 1 is simply to say that the status quo is fine. **************************************************************** From: Brad Moore Sent: Tuesday, May 3, 2011 11:47 PM Here's my ballot: > ... >> Please rank the top three of the following solutions from 1 >> (preferred) to 3 (least >> preferred): >> >> >> ______ The aspect is named Is_Synchronized and the default state is >> Optional [this is the current definition] >> >> ______ The aspect is named Is_Synchronized and the default state is >> Not_Required >> >> ______ The aspect is named Is_Synchronized and the default state is >> Not_Specified >> >> ______ The aspect is named Is_Synchronized and the default state is >> Perhaps_Not >> >> ______ The aspect is named Is_Synchronized and the default state is >> Who_Cares >> >> ______ The aspect is named Is_Synchronized and the default state is >> By_Any >> >> ___2___ The aspect is named Synchronization and the default state is >> Optional >> >> ___3__ The aspect is named Synchronization and the default state is >> Not_Specified >> >> ___1___ The aspect is named Synchronization and the default state is >> Not_Required Choice 3 is a distant 3rd. It seems weird to specify that its not specified. **************************************************************** From: Jean-Pierre Rosen Sent: Wednesday, May 4, 2011 1:59 AM > Please rank the top three of the following solutions from 1 > (preferred) to 3 (least > preferred): > > > ___3___ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ______ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > ___1___ The aspect is named Synchronization and the default state is > Optional > > ______ The aspect is named Synchronization and the default state is > Not_Specified > > ___2___ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ **************************************************************** From: John Barnes Sent: Wednesday, May 4, 2011 6:26 AM > Please rank the top three of the following solutions from 1 > (preferred) to > 3 > (least > preferred): > > > ______ The aspect is named Is_Synchronized and the default state is > Optional [this is the current definition] > > ______ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > ___3___ The aspect is named Synchronization and the default state is > Optional > > ___1___ The aspect is named Synchronization and the default state is > Not_Specified > > ___2___ The aspect is named Synchronization and the default state is > Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ > Glancing at other ballots, it looks at least as if we have got rid of the Is which makes me happy so that I can remove Rant 2 from the Rat. **************************************************************** From: Randy Brukardt Sent: Friday, May 6, 2011 1:59 PM Here is the results so far on the synch aspect vote. We have a tie at this point (two choices both got 2 first place votes, 3 second place votes, and 1 third place votes), and it is pretty clear that the other choices are not going to matter. OTOH, quite a few people (Gary, Steve, Erhard) did not vote that usually do. So I'm going to ask for a second straw poll to decide between the tied options: -------- Please chose one of the following: _______ The aspect is named Synchronization and the default state is Optional _______ The aspect is named Synchronization and the default state is Not_Required ------------------------- > Please rank the top three of the following solutions from 1 > (preferred) to 3 (least preferred): [7 overall votes; note that one > ballot did not give options 2 and 3.] > > > __3_1_3__ The aspect is named Is_Synchronized and the default state > is Optional [this is the current definition] > > __3____ The aspect is named Is_Synchronized and the default state is > Not_Required > > ______ The aspect is named Is_Synchronized and the default state is > Not_Specified > > ______ The aspect is named Is_Synchronized and the default state is > Perhaps_Not > > ______ The aspect is named Is_Synchronized and the default state is > Who_Cares > > ______ The aspect is named Is_Synchronized and the default state is > By_Any > > __2_1_2_2_1_3_ The aspect is named Synchronization and the default > state is Optional > > __1_3_1___ The aspect is named Synchronization and the default state > is Not_Specified > > __1_2_3_1_2_2_ The aspect is named Synchronization and the default > state is Not_Required > > ______ The aspect is named _______________ and the default state is > ________________ **************************************************************** From: Randy Brukardt Sent: Friday, May 6, 2011 1:59 PM And my ballot: Please chose one of the following: ________ The aspect is named Synchronization and the default state is Optional ___X____ The aspect is named Synchronization and the default state is Not_Required **************************************************************** From: Tucker Taft Sent: Friday, May 6, 2011 2:09 PM > Please chose one of the following: > > ___X____ The aspect is named Synchronization and the default state is > Optional > > _______ The aspect is named Synchronization and the default state is > Not_Required > I believe if you look up the definition of "optional" you will find it means "not required." So it seems silly to use the longer phrase. I personally preferred "Not_Specified" but I guess that didn't make the cut... **************************************************************** From: Steve Baird Sent: Friday, May 6, 2011 2:26 PM > I believe if you look up the definition of "optional" > you will find it means "not required." So it seems silly to use the > longer phrase. I'll also vote for "optional", but to say that I don't feel strongly about this one is an understatement. **************************************************************** From: John Barnes Sent: Friday, May 6, 2011 2:33 PM > Please choose one of the following: > > _______ The aspect is named Synchronization and the default state is > Optional > > ____X___ The aspect is named Synchronization and the default state is > Not_Required **************************************************************** From: Edmond Schonberg Sent: Friday, May 6, 2011 2:38 PM > I'll also vote for "optional", but to say that I don't feel strongly > about this one is an understatement. > Ditto, shorter is better **************************************************************** From: Gary Dismukes Sent: Friday, May 6, 2011 2:40 PM > Please chose one of the following: chose => choose > ___X___ The aspect is named Synchronization and the default state is > Optional > > _______ The aspect is named Synchronization and the default state is > Not_Required **************************************************************** From: Bob Duff Sent: Friday, May 6, 2011 2:54 PM > Please chose one of the following: > > __X____ The aspect is named Synchronization and the default state is > Optional > > _______ The aspect is named Synchronization and the default state is > Not_Required **************************************************************** From: Jean-Pierre Rosen Sent: Friday, May 6, 2011 4:10 PM > Please chose one of the following: > > ___1____ The aspect is named Synchronization and the default state is > Optional > > ____2___ The aspect is named Synchronization and the default state is > Not_Required Just because I thought that making them ex-aequo would not help. **************************************************************** From: Brad Moore Sent: Friday, May 6, 2011 7:25 PM > Please chose one of the following: > > _____X__ The aspect is named Synchronization and the default state is > Optional > > _______ The aspect is named Synchronization and the default state is > Not_Required I'm thinking it's better to say what it is, than what it isnt **************************************************************** From: Erhard Ploedereder Sent: Monday, May 9, 2011 11:52 AM Please chose one of the following: ___X____ The aspect is named Synchronization and the default state is Optional _______ The aspect is named Synchronization and the default state is Not_Required Erhard (who usually stays out of naming discussions, only to regret it later ;-) **************************************************************** From: Randy Brukardt Sent: Thursday, May 12, 2011 1:00 AM To summarize the results of this second straw poll: Please chose one of the following: ___8____ The aspect is named Synchronization and the default state is Optional ___2____ The aspect is named Synchronization and the default state is Not_Required This is a pretty clear-cut result, and I've updated the AI to reflect this. Thanks for voting. **************************************************************** From: Randy Brukardt Sent: Thursday, May 12, 2011 1:52 AM A for-the-record note: AI05-0060-1 adds a rule to the DS annex about "pragma Implemented". This needs to be changed to aspect Synchronization as with all of the other references originally from AI05-0030-2. (Another case of the tools complaining about something; as Bob notes, there is a bit of regression testing in the Standard, at least as far as syntax is concerned.) **************************************************************** From: Erhard Ploedereder Sent: Sunday, May 15, 2011 11:31 AM [The appropriate part of a longer message - Editor] AI05-0215-1/08 Pragma Implemented should be an aspect, renamed, and better defined [The class of this AI was wrong; it modifies an Amendment AI, so it also has to be Amendment. Otherwise, it is unchanged.] Approve ______ Disapprove __ X ____ Abstain _______ ============ Why doesn't 9.5(18/3) simply say: "The Synchonization aspect is inherited by derived types." ? The current verbage is rather confusing, since the neded other part of it is in 16/3. Here is the draft of a(n erroneous) comment that I was led to by 18/3: ------ I am surprised that 9.5(18/3) seems to allow that By_Protected_Procedure can become By_Entry in a redefining declaration. Is this really intended, so that I call on a routine that promises no barrier and then the redefining routine does block after all? Not good! ------- I know now that 16/3 prevents it, but why this completely convoluted way of saying "is an inheritable aspect"? I am unconfortable with the term "Optional" in this context after all, since "Synchronization = Optional" definitely reads as if synchronization were optional, which of course is completely contradictory to the restriction to protected operations. (To my shame, I was misled into a different semantics by the "Not_Required" as alternative in the poll, since I presumed that finally normal subprograms renaming entries could get this aspect to communicate their important synchronization property. Well, fooled me.) "Synchronization_Kind =Optional" would be semi-ok. "Synchronization =By_Any" sounds much better to me, now in context. The title of the AI should be made matching the content. **************************************************************** From: Gary Dismukes Sent: Monday, May 16, 2011 4:40 PM [The appropriate part of a longer message - Editor] > AI05-0215-1/08 Pragma Implemented should be an aspect, renamed, and > better defined > [The class of this AI was wrong; it modifies an Amendment AI, so it > also has to be Amendment. > Otherwise, it is unchanged.] > Approve ______ Disapprove ______ Abstain __X____ [Comment: I find myself tending to agree with Erhard's comment regarding Optional vs. By_Any, though not enough to vote for disapproval. Erhard said: I am unconfortable with the term "Optional" in this context after all, since "Synchronization = Optional" definitely reads as if synchronization were optional, which of course is completely contradictory to the restriction to protected operations. (To my shame, I was misled into a different semantics by the "Not_Required" as alternative in the poll, since I presumed that finally normal subprograms renaming entries could get this aspect to communicate their important synchronization property. Well, fooled me.) "Synchronization_Kind =Optional" would be semi-ok. "Synchronization =By_Any" sounds much better to me, now in context. end of Comment] **************************************************************** From: Randy Brukardt Sent: Tuesday, May 17, 2011 1:52 AM > AI05-0215-1/08 Pragma Implemented should be an aspect, renamed, and > better defined > [The class of this AI was wrong; it modifies an Amendment AI, so it also has to be Amendment. > Otherwise, it is unchanged.] > Approve ______ Disapprove __ X ____ Abstain _______ > > ============ > > Why doesn't 9.5(18/3) simply say: "The Synchonization aspect is > inherited by derived types." ? Because this is an aspect of a subprogram, not of a type. Only types inherit aspects, subprograms never do. ("Subprogram" is never mentioned in 13.1(15/1)!). We could have defined inheritance of subprogram aspects, but since we didn't want most of them to be inherited, it would have made things messier. So the two aspects that do have a form of inheritance define it themselves. > The current verbage is rather confusing, since the neded other part of > it is in 16/3. Here is the draft of a(n > erroneous) comment that I was led to by 18/3: > ------ > I am surprised that 9.5(18/3) seems to allow that > By_Protected_Procedure can become By_Entry in a redefining > declaration. Is this really intended, so that I call on a routine that > promises no barrier and then the redefining routine does block after > all? Not good! > ------- > I know now that 16/3 prevents it, but why this completely convoluted > way of saying "is an inheritable aspect"? Because there are no "inheritable aspects" for subprograms. Also note that the two rules in question are separated because one is static semantics and one is a legality rule. Also note that your editor reversed these rules when he put this text into the Standard, because it otherwise had two static semantics sections separated by some legality rules. And it now puts the more important rule first. > I am unconfortable with the term "Optional" in this context after all, > since "Synchronization = Optional" definitely reads as if > synchronization were optional, which of course is completely > contradictory to the restriction to protected operations. I have absolutely no idea what you are talking about here. What "restriction to protected operations"?? There is none required by this aspect! It definitely allows completion by normal subprograms, just as any primitive operation of a synchronized interface does in Ada 2005. That's necessary for compatibility, at a minimum. I note Gary seemed to think this was significant as well, which indicates to me that either I (and a number of others) have missed something fundamental, or a number of people are very confused about synchronized interfaces. > (To my shame, I was misled into a different semantics by the > "Not_Required" > as alternative in the poll, since I presumed that finally normal > subprograms renaming entries could get this aspect to communicate > their important synchronization property. Well, fooled me.) I'm actually a bit surprised that we don't allow this aspect on all subprograms, but that's something to discuss in the future. In any case, a renaming does not have aspects of it's own; "By_Entry" is an unnamed property of a renamed much as "constant" is an unnamed property. It's arguable whether this was a good idea, but the mistake was made by Jean in the Paleozoic era of Ada, and its just a wee bit late to fix now. > "Synchronization_Kind =Optional" would be semi-ok. > "Synchronization =By_Any" sounds much better to me, now in context. A normal subprogram has no synchronization at all; By_Any implies (to me, at least) that the primitive routine does -- but that is clearly not required. > The title of the AI should be made matching the content. It is. "Pragma Implemented should be an aspect, renamed, and better defined" I had to shorten it a bit: "Pragma Implemented should be an aspect rather than a pragma, renamed to Synchronization, and better defined" would be better, but it is way too long for our tools. And keep in mind that this AI is changing an existing AI that defines "pragma Implemented", so not mentioning that at all seems wrong to me. Finally, the original reason for this AI was to fix bugs in pragma Implemented; the other things came later and not mentioning them at all seems wrong as well. "Pragma Implemented should be replaced by aspect Synchronization, and the definition improved" might be better, but it is still too long. And "replaced by" isn't quite what's happening here. Anyway, better suggestions welcome. ****************************************************************