1 // Implementation file for the -*- C++ -*- dynamic memory management header.
2
3 // Copyright (C) 1996-2018 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>
31 namespace
32 {
33 __gnu_cxx::__mutex mx;
34 }
35 #endif
36
37 const std::nothrow_t std::nothrow = std::nothrow_t{ };
38
39 using std::new_handler;
40 namespace
41 {
42 new_handler __new_handler;
43 }
44
45 new_handler
set_new_handler(new_handler handler)46 std::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
60 new_handler
get_new_handler()61 std::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