File : posix-message_queues.ads
------------------------------------------------------------------------------
-- --
-- FLORIST (FSU Implementation of POSIX.5) COMPONENTS --
-- --
-- P O S I X . M E S S A G E _ Q U E U E S --
-- --
-- S p e c --
-- --
-- --
-- This file is a component of FLORIST, an implementation of the POSIX --
-- Ada bindings for use with the GNAT Ada compiler and the FSU Gnu Ada --
-- Runtime Library (GNARL). --
-- --
-- This package specification contains some text extracted from IEEE STD --
-- 1003.5: 1990, Information Technology -- POSIX Ada Language Interfaces --
-- Part 1: Binding for System Application Program Interface, as amended --
-- by IEEE STD 1003.5b: 1996, Amendment 1: Realtime Extensions, copyright --
-- 1996 by the Institute of Electrical and Electronics Engineers, Inc. --
-- --
-- The package specifications in the IEEE standards cited above represent --
-- only a portion of the documents and are not to be interpreteted --
-- outside the context of the documents. The standards must be used in --
-- conjunction with the package specifications in order to claim --
-- conformance. The IEEE takes no responsibility for and will assume no --
-- liability for damages resulting from the reader's misinterpretation of --
-- said information resulting from its out-of-context nature. To order --
-- copies of the IEEE standards, please contact the IEEE Service Center --
-- at 445 Hoes Lane, PO Box 1331, Piscataway, NJ 08855-1331; via phone at --
-- 1-800-678-IEEE, 908-981-1393; or via fax at 908-981-9667. --
-- --
-- These package specifications are distributed in the hope that they --
-- will be useful, but WITHOUT ANY WARRANTY; without even the implied --
-- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
------------------------------------------------------------------------------
-- [$Revision: 1.2 $]
with Ada.Streams,
POSIX.C,
POSIX.Implementation,
POSIX.IO,
POSIX.Configurable_System_Limits,
POSIX.Permissions,
POSIX.Signals;
pragma Elaborate_All (POSIX.Configurable_System_Limits);
package POSIX.Message_Queues is
type Message_Queue_Descriptor is private;
type Attributes is private;
type Message_Queue_Options is new POSIX.Option_Set;
Non_Blocking : constant Message_Queue_Options :=
Message_Queue_Options (POSIX.IO.Non_Blocking);
subtype Message_Priority is
Integer range 0 ..
POSIX.Configurable_System_Limits.Message_Priority_Maximum;
-- ?????
-- POSIX.5b may need revision here. By definining the range
-- of Message_Priority sufficiently precisely, we end up raising
-- Constraint_Error in all situations where the priority is out
-- of the supported range, but the standard says we should raise
-- POSIX_Error with Invalid_Argument in these situations. In
-- particular, see the procedure Send. Technically, it is not
-- necessary to list Constraint_Error as a possibility in the
-- Error Handling section of the standard, since it follows from
-- the Ada language definition that Constraint_Error is raised
-- under such circumstances, but it might be better if there were
-- an explicit note pointing this out.
procedure Set_Max_Messages
(Attrs : in out Attributes;
Value : Natural);
function Get_Max_Messages (Attrs : Attributes) return Natural;
procedure Set_Message_Length
(Attrs : in out Attributes;
Value : Natural);
function Get_Message_Length (Attrs : Attributes) return Natural;
procedure Set_Options
(Attrs : in out Attributes;
Value : Message_Queue_Options);
function Get_Options (Attrs : Attributes) return Message_Queue_Options;
function Get_Message_Count (Attrs : Attributes) return Natural;
function Open
(Name : POSIX.POSIX_String;
Mode : POSIX.IO.File_Mode;
Options : POSIX.IO.Open_Option_Set := -- POSIX.IO.Empty_Set;
POSIX.IO.Open_Option_Set (POSIX.IO.Empty_Set);
-- Conversion is only to work around a GNAT3.09 problem.
Masked_Signals : POSIX.Signal_Masking := POSIX.RTS_Signals)
return Message_Queue_Descriptor;
function Open_Or_Create
(Name : POSIX.POSIX_String;
Mode : POSIX.IO.File_Mode;
Permissions : POSIX.Permissions.Permission_Set;
Options : POSIX.IO.Open_Option_Set := -- POSIX.IO.Empty_Set;
POSIX.IO.Open_Option_Set (POSIX.IO.Empty_Set);
-- Conversion is only to work around a GNAT3.09 problem.
Masked_Signals : POSIX.Signal_Masking := POSIX.RTS_Signals)
return Message_Queue_Descriptor;
function Open_Or_Create
(Name : POSIX.POSIX_String;
Mode : POSIX.IO.File_Mode;
Permissions : POSIX.Permissions.Permission_Set;
Options : POSIX.IO.Open_Option_Set := -- POSIX.IO.Empty_Set;
POSIX.IO.Open_Option_Set (POSIX.IO.Empty_Set);
-- Conversion is only to work around a GNAT3.09 problem.
Attrs : Attributes;
Masked_Signals : POSIX.Signal_Masking := POSIX.RTS_Signals)
return Message_Queue_Descriptor;
procedure Close (MQ : in out Message_Queue_Descriptor);
procedure Unlink_Message_Queue (Name : in POSIX.POSIX_String);
procedure Send
(MQ : in Message_Queue_Descriptor;
Message : in Ada.Streams.Stream_Element_Array;
Priority : in Message_Priority;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Receive
(MQ : in Message_Queue_Descriptor;
Message : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset;
Priority : out Message_Priority;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
generic
type Message_Type is private;
package Generic_Message_Queues is
procedure Send
(MQ : in Message_Queue_Descriptor;
Message : in Message_Type;
Priority : in Message_Priority;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Receive
(MQ : in Message_Queue_Descriptor;
Message : out Message_Type;
Priority : out Message_Priority;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
function Get_Error_Buffer return Ada.Streams.Stream_Element_Array;
end Generic_Message_Queues;
procedure Request_Notify
(MQ : in Message_Queue_Descriptor;
Event : in POSIX.Signals.Signal_Event);
procedure Remove_Notify (MQ : in Message_Queue_Descriptor);
procedure Set_Attributes
(MQ : in Message_Queue_Descriptor;
New_Attrs : in Attributes;
Old_Attrs : out Attributes);
procedure Set_Attributes
(MQ : in Message_Queue_Descriptor;
New_Attrs : in Attributes);
function Get_Attributes (MQ : Message_Queue_Descriptor) return Attributes;
private
type Message_Queue_Descriptor is new POSIX.C.mqd_t;
type Attributes is record
Attrs : aliased POSIX.C.struct_mq_attr := (0, 0, 0, 0);
end record;
end POSIX.Message_Queues;
-- .... Change POSIX.5b?????
-- These interfaces would be easier to use if it were possible to specify
-- a message buffer via its address, rather than an unconstrained array
-- parameter. The present interface forces people to copy data into the
-- buffer, and possibly also out from the buffer. It would be more
-- convenient and efficient to pass references to data to these calls and
-- leave the data itself in-place.