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Diffstat (limited to 'gcc-4.8.3/gcc/ada/g-boubuf.ads')
| -rw-r--r-- | gcc-4.8.3/gcc/ada/g-boubuf.ads | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/g-boubuf.ads b/gcc-4.8.3/gcc/ada/g-boubuf.ads new file mode 100644 index 000000000..f94641ff6 --- /dev/null +++ b/gcc-4.8.3/gcc/ada/g-boubuf.ads @@ -0,0 +1,101 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- G N A T . B O U N D E D _ B U F F E R S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2003-2010, AdaCore -- +-- -- +-- 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 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- 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 generic bounded buffer abstraction. +-- Instances are useful directly or as parts of the implementations of other +-- abstractions, such as mailboxes. + +-- Bounded_Buffer is declared explicitly as a protected type, rather than as +-- a simple limited private type completed as a protected type, so that +-- clients may make calls accordingly (i.e., conditional/timed entry calls). + +with System; + +generic + type Element is private; + -- The type of the values contained within buffer objects + +package GNAT.Bounded_Buffers is + pragma Pure; + + type Content is array (Positive range <>) of Element; + -- Content is an internal artefact that cannot be hidden because protected + -- types cannot contain type declarations. + + Default_Ceiling : constant System.Priority := System.Default_Priority; + -- A convenience value for the Ceiling discriminant + + protected type Bounded_Buffer + (Capacity : Positive; + -- Objects of type Bounded_Buffer specify the maximum number of Element + -- values they can hold via the discriminant Capacity. + + 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. + is + pragma Priority (Ceiling); + + entry Insert (Item : Element); + -- Insert Item into the buffer, blocks caller until space is available + + entry Remove (Item : out Element); + -- Remove next available Element from buffer. Blocks caller until an + -- Element is available. + + function Empty return Boolean; + -- Returns whether the instance contains any Elements. + -- Note: State may change immediately after call returns. + + function Full return Boolean; + -- Returns whether any space remains within the instance. + -- Note: State may change immediately after call returns. + + function Extent return Natural; + -- Returns the number of Element values currently held + -- within the instance. + -- Note: State may change immediately after call returns. + + private + Values : Content (1 .. Capacity); + -- The container for the values held by the buffer instance + + Next_In : Positive := 1; + -- The index of the next Element inserted. Wraps around + + Next_Out : Positive := 1; + -- The index of the next Element removed. Wraps around + + Count : Natural := 0; + -- The number of Elements currently held + end Bounded_Buffer; + +end GNAT.Bounded_Buffers; |