File : posix-asynchronous_io.ads
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-- --
-- FLORIST (FSU Implementation of POSIX.5) COMPONENTS --
-- --
-- P O S I X . A S Y N C H R O N O U S _ I O --
-- --
-- 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. --
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-- These package specifications are distributed in the hope that they --
-- will be useful, but WITHOUT ANY WARRANTY; without even the implied --
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-- [$Revision: 1.1.1.1 $]
with Ada.Streams,
POSIX.C,
POSIX.IO,
POSIX.Signals;
package POSIX.Asynchronous_IO is
type AIO_Descriptor is private;
function Create_AIO_Control_Block return AIO_Descriptor;
procedure Destroy_AIO_Control_Block (AD : in out AIO_Descriptor);
type List_IO_Operations is
(No_Op,
Read,
Write);
type IO_Array_Pointer is access Ada.Streams.Stream_Element_Array;
for IO_Array_Pointer'Size use Standard'Address_Size;
-- force this to be a "thin" pointer, like C pointers
function Get_File (AD : AIO_Descriptor)
return POSIX.IO.File_Descriptor;
procedure Set_File
(AD : in AIO_Descriptor;
File : in POSIX.IO.File_Descriptor);
function Get_Offset (AD : AIO_Descriptor) return POSIX.IO.IO_Offset;
procedure Set_Offset
(AD : in AIO_Descriptor;
Offset : in POSIX.IO.IO_Offset);
function Get_Buffer (AD : AIO_Descriptor) return IO_Array_Pointer;
procedure Set_Buffer
(AD : in AIO_Descriptor;
Buffer : in IO_Array_Pointer);
function Get_Length (AD : AIO_Descriptor) return POSIX.IO_Count;
procedure Set_Length
(AD : in AIO_Descriptor;
Length : in POSIX.IO_Count);
function Get_Priority_Reduction (AD : AIO_Descriptor) return Natural;
procedure Set_Priority_Reduction
(AD : in AIO_Descriptor;
Priority_Reduction : in Natural);
function Get_Event (AD : AIO_Descriptor) return POSIX.Signals.Signal_Event;
procedure Set_Event
(AD : in AIO_Descriptor;
Event : in POSIX.Signals.Signal_Event);
function Get_Operation (AD : AIO_Descriptor) return List_IO_Operations;
procedure Set_Operation
(AD : in AIO_Descriptor;
Operation : in List_IO_Operations);
procedure Read (AD : in AIO_Descriptor);
procedure Write (AD : in AIO_Descriptor);
type AIO_Descriptor_List is
array (Positive range <>) of aliased AIO_Descriptor;
-- .... "aliased" is not in POSIX.5b
-- ????? Change POSIX.5b?
-- This array should probably have been a private (or limited private)
-- type, so that we could hide a copy of the C-style array of pointers
-- inside the object. As things stand, the need to be able to recover
-- an Ada pointer to the buffer of each AIOCB is forcing us to put a
-- wrapper around each AIOCB pointer, and so we cannot pass the array
-- directly as argument to any C system call. Instead, we have to
-- dynamically create a C-style array at the point of call.
procedure List_IO_No_Wait
(List : in out AIO_Descriptor_List;
Event : in POSIX.Signals.Signal_Event);
procedure List_IO_Wait
(List : in out AIO_Descriptor_List;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
type AIO_Status is
(In_Progress,
Completed_Successfully,
Canceled);
function Get_AIO_Status (AD : AIO_Descriptor) return AIO_Status;
function Get_AIO_Error_Code (AD : AIO_Descriptor) return POSIX.Error_Code;
function Get_Bytes_Transferred (AD : AIO_Descriptor) return POSIX.IO_Count;
type Cancelation_Status is
(Canceled,
Not_Canceled,
All_Done);
function Cancel (AD : AIO_Descriptor) return Cancelation_Status;
function Cancel (File : POSIX.IO.File_Descriptor) return Cancelation_Status;
procedure Await_IO_Or_Timeout
(AD : in AIO_Descriptor;
Timeout : in POSIX.Timespec;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Await_IO
(AD : in AIO_Descriptor;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Await_IO_Or_Timeout
(List : in AIO_Descriptor_List;
Timeout : in POSIX.Timespec;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Await_IO
(List : in AIO_Descriptor_List;
Masked_Signals : in POSIX.Signal_Masking := POSIX.RTS_Signals);
procedure Synchronize_File (AD : in AIO_Descriptor);
procedure Synchronize_Data (AD : in AIO_Descriptor);
private
-- The following wrapper is needed around the C struct aiocb
-- in order to preserve the Ada "fat" pointer (including constraint info)
-- that we need in order to be able to recover the range constraint of the
-- Stream_Element_Array object referenced by the aiocb.
-- Our code is going to rely on the component C being allocated in first
-- position. There will be code in the package body to verify this
-- assumption.
type Aiocb_Wrapper is record
C : aliased POSIX.C.struct_aiocb;
P : IO_Array_Pointer;
end record;
type AIO_Descriptor is access Aiocb_Wrapper;
end POSIX.Asynchronous_IO;