Package Name: system.task_specific_data
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . T A S K _ S P E C I F I C _ D A T A --
-- --
-- S p e c --
-- --
-- $Revision: 1.12 $ --
-- --
-- Copyright (C) 1992,1993,1994,1995,1996 Free Software Foundation, 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 contains an interface for manipulation of task specific data
package System.Task_Specific_Data is
-- Here we define a single type that encapsulates the various task
-- specific data. This type is used to store the necessary data into
-- the Task_Control_Block. This record could use detailed comments ???
type TSD is
record
Jmpbuf_Address : Address := Null_Address;
GNAT_Exception : Address := Null_Address;
Sec_Stack_Addr : Address := Null_Address;
Exc_Stack_Addr : Address := Null_Address;
Message_Length : Integer := 0;
Message_Addr : Address := Null_Address;
end record;
-- This package just re-exports the Get/Set routines for the various
-- Task Specific Data (TSD) elements from System.Tasking_Soft_Links,
-- but as callable subprograms instead of objects of access to
-- subprogram types.
function Get_Jmpbuf_Address return Address;
procedure Set_Jmpbuf_Address (Addr : Address);
pragma Inline (Get_Jmpbuf_Address);
pragma Inline (Set_Jmpbuf_Address);
-- These routines provide a task specific address used to store the
-- address of the current longjmp/setjmp jump buffer for exception
-- management (under the current scheme which uses longjmp/setjmp)
function Get_GNAT_Exception return Address;
procedure Set_GNAT_Exception (Addr : Address);
pragma Inline (Get_GNAT_Exception);
pragma Inline (Set_GNAT_Exception);
-- These routines provide a task specific address used to temporarily
-- store the address of the current exception during propagation.
function Get_Sec_Stack_Addr return Address;
procedure Set_Sec_Stack_Addr (Addr : Address);
pragma Inline (Get_Sec_Stack_Addr);
pragma Inline (Set_Sec_Stack_Addr);
-- These routines provide a task specific address used to reference
-- the currently allocated secondary stack.
function Get_Exc_Stack_Addr return Address;
procedure Set_Exc_Stack_Addr (Addr : Address);
pragma Inline (Get_Exc_Stack_Addr);
pragma Inline (Set_Exc_Stack_Addr);
-- These routines provide the address of a task-specific stack used
-- for the propagation of exceptions in response to synchronous faults.
-- This alternate stack is necessary when propagating Storage_Error
-- resulting from a stack overflow, as the task's primary stack is
-- exhausted. Non-SGI platforms may implement these as dummy bodies.
function Get_Message_Length return Integer;
procedure Set_Message_Length (Len : Integer);
pragma Inline (Get_Message_Length);
pragma Inline (Set_Message_Length);
-- These routines provide access to the length of the currently raised
-- exception's message. O means no message. Negative values have a
-- special purpose in connection with Assert_Failure (see description
-- in System.Assertions (s-assert.adb) for explanation). If a negative
-- value is set using Set_Message_Length, then a subsequent call to
-- Set_Message_Length with an argument of zero will, instead of setting
-- the length to zero, change the sign of the previously set negative
-- length.
function Get_Message_Addr return Address;
procedure Set_Message_Addr (Addr : Address);
pragma Inline (Get_Message_Addr);
pragma Inline (Set_Message_Addr);
-- These routines provide access to the buffer containing the currently
-- raised exception's message. The actual message is:
-- To_Big_String_Ptr (Get_Message_Addr).all (1 .. Get_Message_Length)
procedure Create_TSD (New_TSD : in out TSD);
-- Called from s-tassta when a new thread is created to perform
-- any required initialization of the TSD.
procedure Destroy_TSD (Old_TSD : in out TSD);
-- Called from s-tassta just before a thread is destroyed to perform
-- any required finalization.
end System.Task_Specific_Data;