xref: /dflybsd-src/contrib/gcc-8.0/libstdc++-v3/src/c++11/shared_ptr.cc (revision 38fd149817dfbff97799f62fcb70be98c4e32523)
1*38fd1498Szrj // Support for pointer abstractions -*- C++ -*-
2*38fd1498Szrj 
3*38fd1498Szrj // Copyright (C) 2011-2018 Free Software Foundation, Inc.
4*38fd1498Szrj //
5*38fd1498Szrj // This file is part of the GNU ISO C++ Library.  This library is free
6*38fd1498Szrj // software; you can redistribute it and/or modify it under the
7*38fd1498Szrj // terms of the GNU General Public License as published by the
8*38fd1498Szrj // Free Software Foundation; either version 3, or (at your option)
9*38fd1498Szrj // any later version.
10*38fd1498Szrj 
11*38fd1498Szrj // This library is distributed in the hope that it will be useful,
12*38fd1498Szrj // but WITHOUT ANY WARRANTY; without even the implied warranty of
13*38fd1498Szrj // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*38fd1498Szrj // GNU General Public License for more details.
15*38fd1498Szrj 
16*38fd1498Szrj // Under Section 7 of GPL version 3, you are granted additional
17*38fd1498Szrj // permissions described in the GCC Runtime Library Exception, version
18*38fd1498Szrj // 3.1, as published by the Free Software Foundation.
19*38fd1498Szrj 
20*38fd1498Szrj // You should have received a copy of the GNU General Public License and
21*38fd1498Szrj // a copy of the GCC Runtime Library Exception along with this program;
22*38fd1498Szrj // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23*38fd1498Szrj // <http://www.gnu.org/licenses/>.
24*38fd1498Szrj 
25*38fd1498Szrj #include <memory>
26*38fd1498Szrj 
27*38fd1498Szrj #include "mutex_pool.h"
28*38fd1498Szrj 
29*38fd1498Szrj namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden)
30*38fd1498Szrj {
31*38fd1498Szrj   /* Returns different instances of __mutex depending on the passed index
32*38fd1498Szrj    * in order to limit contention.
33*38fd1498Szrj    */
34*38fd1498Szrj   __gnu_cxx::__mutex&
get_mutex(unsigned char i)35*38fd1498Szrj   get_mutex(unsigned char i)
36*38fd1498Szrj   {
37*38fd1498Szrj     static __gnu_cxx::__mutex m[mask + 1];
38*38fd1498Szrj     return m[i];
39*38fd1498Szrj   }
40*38fd1498Szrj }
41*38fd1498Szrj 
42*38fd1498Szrj namespace std _GLIBCXX_VISIBILITY(default)
43*38fd1498Szrj {
44*38fd1498Szrj _GLIBCXX_BEGIN_NAMESPACE_VERSION
45*38fd1498Szrj 
46*38fd1498Szrj   bad_weak_ptr::~bad_weak_ptr() noexcept = default;
47*38fd1498Szrj 
48*38fd1498Szrj   char const*
what() const49*38fd1498Szrj   bad_weak_ptr::what() const noexcept
50*38fd1498Szrj   { return "bad_weak_ptr"; }
51*38fd1498Szrj 
52*38fd1498Szrj #ifdef __GTHREADS
53*38fd1498Szrj   namespace
54*38fd1498Szrj   {
key(const void * addr)55*38fd1498Szrj     inline unsigned char key(const void* addr)
56*38fd1498Szrj     { return _Hash_impl::hash(addr) & __gnu_internal::mask; }
57*38fd1498Szrj   }
58*38fd1498Szrj 
_Sp_locker(const void * p)59*38fd1498Szrj   _Sp_locker::_Sp_locker(const void* p) noexcept
60*38fd1498Szrj   {
61*38fd1498Szrj     if (__gthread_active_p())
62*38fd1498Szrj       {
63*38fd1498Szrj 	_M_key1 = _M_key2 = key(p);
64*38fd1498Szrj         __gnu_internal::get_mutex(_M_key1).lock();
65*38fd1498Szrj       }
66*38fd1498Szrj     else
67*38fd1498Szrj       _M_key1 = _M_key2 = __gnu_internal::invalid;
68*38fd1498Szrj   }
69*38fd1498Szrj 
_Sp_locker(const void * p1,const void * p2)70*38fd1498Szrj   _Sp_locker::_Sp_locker(const void* p1, const void* p2) noexcept
71*38fd1498Szrj   {
72*38fd1498Szrj     if (__gthread_active_p())
73*38fd1498Szrj       {
74*38fd1498Szrj 	_M_key1 = key(p1);
75*38fd1498Szrj 	_M_key2 = key(p2);
76*38fd1498Szrj 	if (_M_key2 < _M_key1)
77*38fd1498Szrj 	  __gnu_internal::get_mutex(_M_key2).lock();
78*38fd1498Szrj 	__gnu_internal::get_mutex(_M_key1).lock();
79*38fd1498Szrj 	if (_M_key2 > _M_key1)
80*38fd1498Szrj 	  __gnu_internal::get_mutex(_M_key2).lock();
81*38fd1498Szrj       }
82*38fd1498Szrj     else
83*38fd1498Szrj       _M_key1 = _M_key2 = __gnu_internal::invalid;
84*38fd1498Szrj   }
85*38fd1498Szrj 
~_Sp_locker()86*38fd1498Szrj   _Sp_locker::~_Sp_locker()
87*38fd1498Szrj   {
88*38fd1498Szrj     if (_M_key1 != __gnu_internal::invalid)
89*38fd1498Szrj       {
90*38fd1498Szrj 	__gnu_internal::get_mutex(_M_key1).unlock();
91*38fd1498Szrj 	if (_M_key2 != _M_key1)
92*38fd1498Szrj 	  __gnu_internal::get_mutex(_M_key2).unlock();
93*38fd1498Szrj       }
94*38fd1498Szrj   }
95*38fd1498Szrj #endif
96*38fd1498Szrj 
97*38fd1498Szrj _GLIBCXX_END_NAMESPACE_VERSION
98*38fd1498Szrj } // namespace
99