1// Implementation file for the -*- C++ -*- dynamic memory management header.
2
3// Copyright (C) 1996-2017 Free Software Foundation, Inc.
4//
5// This file is part of GCC.
6//
7// GCC is free software; you can redistribute it and/or modify
8// it under the terms of the GNU General Public License as published by
9// the Free Software Foundation; either version 3, or (at your option)
10// any later version.
11//
12// GCC is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16//
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24// <http://www.gnu.org/licenses/>.
25
26#include "new"
27#include <bits/atomic_lockfree_defines.h>
28
29#if ATOMIC_POINTER_LOCK_FREE < 2
30#include <ext/concurrence.h>
31namespace
32{
33 __gnu_cxx::__mutex mx;
34}
35#endif
36
37const std::nothrow_t std::nothrow = std::nothrow_t{ };
38
39using std::new_handler;
40namespace
41{
42 new_handler __new_handler;
43}
44
45new_handler
46std::set_new_handler (new_handler handler) throw()
47{
48 new_handler prev_handler;
49#if ATOMIC_POINTER_LOCK_FREE > 1
50 __atomic_exchange (&__new_handler, &handler, &prev_handler,
51 __ATOMIC_ACQ_REL);
52#else
53 __gnu_cxx::__scoped_lock l(mx);
54 prev_handler = __new_handler;
55 __new_handler = handler;
56#endif
57 return prev_handler;
58}
59
60new_handler
61std::get_new_handler () noexcept
62{
63 new_handler handler;
64#if ATOMIC_POINTER_LOCK_FREE > 1
65 __atomic_load (&__new_handler, &handler, __ATOMIC_ACQUIRE);
66#else
67 __gnu_cxx::__scoped_lock l(mx);
68 handler = __new_handler;
69#endif
70 return handler;
71}
72