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Diffstat (limited to 'gcc/ada/g-boumai.ads')
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diff --git a/gcc/ada/g-boumai.ads b/gcc/ada/g-boumai.ads new file mode 100644 index 00000000000..a6dbf75337b --- /dev/null +++ b/gcc/ada/g-boumai.ads @@ -0,0 +1,98 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- G N A T . B O U N D E D _ M A I L B O X E S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2003 Ada Core Technologies, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides a thread-safe asynchronous communication facility +-- in the form of mailboxes. Individual mailbox objects are bounded in size +-- to a value specified by their Capacity discriminants. + +-- Mailboxes actually hold references to messages, not the message values +-- themselves. + +-- Type Mailbox is defined explicitly as a protected type (via derivation +-- from a protected type) so that clients may treat them accordingly (for +-- example, by making conditional/timed entry calls). + +with System; +with GNAT.Bounded_Buffers; + +generic + type Message (<>) is limited private; + type Message_Reference is access all Message; + -- Mailboxes hold references to Message values, of this type + +package GNAT.Bounded_Mailboxes is + pragma Preelaborate; + + package Message_Refs is + new GNAT.Bounded_Buffers (Message_Reference); + + type Mailbox is new Message_Refs.Bounded_Buffer; + + -- Type Mailbox has two inherited discriminants: + + -- Capacity : Positive; + -- Capacity is the maximum number of Message references + -- possibly contained at any given instant. + + -- Ceiling : System.Priority; + -- Users must specify the ceiling priority for the object. + -- If the Real-Time Systems Annex is not in use this value + -- is not important. + + -- Protected type Mailbox has the following inherited interface: + + -- entry Insert (Item : in Message_Reference); + -- Insert Item into the Mailbox. Blocks caller + -- until space is available. + + -- entry Remove (Item : out Message_Reference); + -- Remove next available Message_Reference from Mailbox. + -- Blocks caller until a Message_Reference is available. + + -- function Empty return Boolean; + -- Returns whether the Mailbox contains any Message_References. + -- Note: State may change immediately after call returns. + + -- function Full return Boolean; + -- Returns whether any space remains within the Mailbox. + -- Note: State may change immediately after call returns. + + -- function Extent return Natural; + -- Returns the number of Message_Reference values currently held + -- within the Mailbox. + -- Note: State may change immediately after call returns. + + Default_Ceiling : constant System.Priority := Message_Refs.Default_Ceiling; + -- A convenience value for the Ceiling discriminant + +end GNAT.Bounded_Mailboxes; |