E.4.1 Asynchronous Remote CallsPragma Asynchronous
1/3
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AI05-0229-1}
[This subclause introduces the
aspect pragma
Asynchronous which
can be specified to allow allows
a remote subprogram call to return prior to completion of the execution
of the corresponding remote subprogram body.]
Paragraphs
2 through 7 were deleted.
Syntax
2/3
3/3
Legality Rules
4/3
5/3
One or more remote procedures;
the formal parameters of the procedure(s) shall all be of mode in;
6/3
The first subtype of a remote
access-to-procedure type; the formal parameters of the designated profile
of the type shall all be of mode in;
7/3
The first subtype of a remote
access-to-class-wide type.
Static Semantics
8/3
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AI05-0229-1}
For a remote procedure,
the following language-defined representation aspect may be specified:
A pragma Asynchronous is a representation pragma.
When applied to a type, it specifies the type-related asynchronous
aspect of the type. 8.1/3
Asynchronous
The type of aspect Asynchronous is Boolean. If
directly specified, the aspect_definition
shall be a static expression. If not specified, the aspect is False.
8.a/3
Aspect Description
for Asynchronous: Remote
procedure calls are asynchronous; the caller continues without waiting
for the call to return.
8.2/3
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AI05-0229-1}
For a remote access type, the following language-defined
representation aspect may be specified: 8.3/3
Asynchronous
The type of aspect Asynchronous is Boolean. If
directly specified, the aspect_definition
shall be a static expression. If not specified (including by inheritance),
the aspect is False.
Legality Rules
8.4/3
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AI05-0229-1}
If aspect Asynchronous is specified for a remote
procedure, the formal parameters of the procedure shall all be of mode
in.8.5/3
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AI05-0229-1}
If aspect Asynchronous is specified for a remote
access type, the type shall be a remote access-to-class-wide type, or
the type shall be a remote access-to-procedure type with the formal parameters
of the designated profile of the type all of mode in. Dynamic Semantics
9/3
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AI05-0229-1}
A remote call is
asynchronous
if it is a call to a procedure, or a call through a value of an access-to-procedure
type,
for to
which
aspect a pragma
Asynchronous
is True applies.
In addition, if
aspect a
pragma Asynchronous
is True for applies
to a remote access-to-class-wide type, then a dispatching call
on a procedure with a controlling operand designated by a value of the
type is asynchronous if the formal parameters of the procedure are all
of mode
in.
Implementation Requirements
10
Asynchronous remote procedure calls shall be implemented
such that the corresponding body executes at most once as a result of
the call.
10.a
To be honest: It is not clear that this
rule can be tested or even defined formally.
Extensions to Ada 2005
10.b/3
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
