1 /* Determine whether block of given size can be allocated on the stack or not.
2 Copyright (C) 2002-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If
17 not, see <https://www.gnu.org/licenses/>. */
18
19 #include <alloca.h>
20 #include <stdlib.h>
21 #include <sys/param.h>
22 #include <pthreadP.h>
23
24
25 int
__libc_alloca_cutoff(size_t size)26 __libc_alloca_cutoff (size_t size)
27 {
28 return size <= (MIN (__MAX_ALLOCA_CUTOFF,
29 THREAD_GETMEM (THREAD_SELF, stackblock_size) / 4
30 /* The main thread, before the thread library is
31 initialized, has zero in the stackblock_size
32 element. Since it is the main thread we can
33 assume the maximum available stack space. */
34 ?: __MAX_ALLOCA_CUTOFF * 4));
35 }
36 libc_hidden_def (__libc_alloca_cutoff)
37