/src/wrappers/common/library/obsolete/expanded_wrapper.e

 1indexing
 2	description:
 3		"."
 4	copyright:
 5		"[
 6					Copyright (C) 2008 Paolo Redaelli
 7
 8					This library is free software; you can redistribute it and/or
 9					modify it under the terms of the GNU Lesser General Public License
10					as published by the Free Software Foundation; either version 2.1 of
11					the License, or (at your option) any later version.
12
13					This library is distributed in the hope that it will be useful, but
14					WITHOUT ANY WARRANTY; without even the implied warranty of
15					MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16					Lesser General Public License for more details.
17
18					You should have received a copy of the GNU Lesser General Public
19					License along with this library; if not, write to the Free Software
20					Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21					02110-1301 USA
22			]"
23deferred class EXPANDED_WRAPPER
24	-- A wrapper for an object on the stack
25	-- WARNING: This class will be not useful anymore when external types will
26	-- be available and fully tested.
27
28inherit
29	C_STRUCT
30		redefine allocate
31		end
32	C_OWNED
33	INTERNALS_HANDLER
34		undefine copy, is_equal
35		end
36
37feature {} --
38	allocate is
39		do
40			handle := alloca(struct_size)
41		end
42
43	alloca (a_size: INTEGER): POINTER is
44			-- The alloca() function allocates size bytes of space in the
45			-- stack frame of the caller.  This temporary space is
46			-- automatically freed when the function that called alloca()
47			-- returns to its caller.
48			-- The alloca() function returns a pointer to the beginning of
49			-- the allocated space.  If the allocation causes stack
50			-- overflow, program behavior is undefined.
51			-- The alloca() function is machine- and compiler-dependent.
52			-- For certain applications, its use can improve efficiency
53			-- compared to the use of malloc(3) plus free(3).  In certain
54			-- cases, it can also simplify memory deallocation in
55			-- applications that use longjmp(3) or siglongjmp(3).
56			-- Otherwise, its use is discouraged.
57			-- Because the space allocated by alloca() is allocated
58			-- within the stack frame, that space is automatically freed
59			-- if the function return is jumped over by a call to
60			-- longjmp(3) or siglongjmp(3).
61		require
62			positive: a_size > 0
63		external "C use <alloca.h>"
64		end
65
66invariant
67	used_in_expanded_types: to_internals.type_is_expanded
68	-- When using previous versions of the compiler (<2.3)
69	-- this invariant would become `is_expanded_type'
70
71end -- class EXPANDED_WRAPPER