1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . S T A C K _ C H E C K I N G . O P E R A T I O N S --
9 -- Copyright (C) 1999-2004 Free Software Foundation, Inc. --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This package provides a implementation of stack checking operations
35 -- using comparison with stack base and limit.
37 pragma Restrictions (No_Elaboration_Code);
38 -- We want to guarantee the absence of elaboration code because the
39 -- binder does not handle references to this package.
42 -- Turn off polling, we do not want polling to take place during stack
43 -- checking operations. It causes infinite loops and other problems.
45 package System.Stack_Checking.Operations is
46 procedure Update_Stack_Cache (Stack : Stack_Access);
47 -- Set the stack cache for the current task. Note that this is only
48 -- for optimization purposes, nothing can be assumed about the
49 -- contents of the cache at any time, see Set_Stack_Info.
51 procedure Invalidate_Stack_Cache (Any_Stack : Stack_Access);
52 -- Invalidate cache entries for the task T that owns Any_Stack.
53 -- This causes the Set_Stack_Info function to be called during
54 -- the next stack check done by T. This can be used to interrupt
55 -- task T asynchronously.
56 -- Stack_Check should be called in loops for this to work reliably.
58 function Stack_Check (Stack_Address : System.Address) return Stack_Access;
59 -- This version of Stack_Check should not be inlined.
63 Cache : aliased Stack_Access := Null_Stack;
65 pragma Export (C, Cache, "_gnat_stack_cache");
66 pragma Export (C, Stack_Check, "_gnat_stack_check");
68 end System.Stack_Checking.Operations;