E.4.1 Pragma Asynchronous
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[This subclause introduces the pragma Asynchronous
which allows a remote subprogram call to return prior to completion of
the execution of the corresponding remote subprogram body.]
Syntax
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The form of
a pragma Asynchronous is as follows:
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pragma Asynchronous(
local_name);
Legality Rules
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The local_name
of a pragma Asynchronous shall denote either:
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- One or more remote procedures; the
formal parameters of the procedure(s) shall all be of mode in;
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- 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;
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- The first subtype of a remote access-to-class-wide
type.
Static Semantics
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{representation pragma
(Asynchronous) [partial]} {pragma,
representation (Asynchronous) [partial]} A
pragma Asynchronous is a representation pragma. When applied to a type,
it specifies the type-related
asynchronous aspect of the type.
Dynamic Semantics
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{remote procedure
call (asynchronous)} {asynchronous
(remote procedure call)} 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, to which a pragma Asynchronous
applies. In addition, if a pragma Asynchronous 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
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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.
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