// Allocator details.
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// Allocator details.
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// Copyright (C) 2004, 2005, 2006, 2009 Free Software Foundation, Inc.
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// Copyright (C) 2004, 2005, 2006, 2009 Free Software Foundation, Inc.
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//
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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// <http://www.gnu.org/licenses/>.
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//
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//
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// ISO C++ 14882:
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// ISO C++ 14882:
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//
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//
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#include <bits/c++config.h>
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#include <bits/c++config.h>
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#include <cstdlib>
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#include <cstdlib>
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#include <ext/pool_allocator.h>
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#include <ext/pool_allocator.h>
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namespace
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namespace
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{
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{
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__gnu_cxx::__mutex&
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__gnu_cxx::__mutex&
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get_palloc_mutex()
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get_palloc_mutex()
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{
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{
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static __gnu_cxx::__mutex palloc_mutex;
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static __gnu_cxx::__mutex palloc_mutex;
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return palloc_mutex;
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return palloc_mutex;
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}
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}
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} // anonymous namespace
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} // anonymous namespace
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_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
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_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
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// Definitions for __pool_alloc_base.
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// Definitions for __pool_alloc_base.
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__pool_alloc_base::_Obj* volatile*
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__pool_alloc_base::_Obj* volatile*
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__pool_alloc_base::_M_get_free_list(size_t __bytes) throw ()
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__pool_alloc_base::_M_get_free_list(size_t __bytes) throw ()
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{
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{
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size_t __i = ((__bytes + (size_t)_S_align - 1) / (size_t)_S_align - 1);
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size_t __i = ((__bytes + (size_t)_S_align - 1) / (size_t)_S_align - 1);
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return _S_free_list + __i;
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return _S_free_list + __i;
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}
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}
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__mutex&
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__mutex&
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__pool_alloc_base::_M_get_mutex() throw ()
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__pool_alloc_base::_M_get_mutex() throw ()
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{ return get_palloc_mutex(); }
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{ return get_palloc_mutex(); }
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// Allocate memory in large chunks in order to avoid fragmenting the
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// Allocate memory in large chunks in order to avoid fragmenting the
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// heap too much. Assume that __n is properly aligned. We hold the
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// heap too much. Assume that __n is properly aligned. We hold the
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// allocation lock.
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// allocation lock.
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char*
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char*
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__pool_alloc_base::_M_allocate_chunk(size_t __n, int& __nobjs)
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__pool_alloc_base::_M_allocate_chunk(size_t __n, int& __nobjs)
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{
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{
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char* __result;
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char* __result;
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size_t __total_bytes = __n * __nobjs;
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size_t __total_bytes = __n * __nobjs;
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size_t __bytes_left = _S_end_free - _S_start_free;
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size_t __bytes_left = _S_end_free - _S_start_free;
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if (__bytes_left >= __total_bytes)
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if (__bytes_left >= __total_bytes)
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{
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{
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__result = _S_start_free;
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__result = _S_start_free;
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_S_start_free += __total_bytes;
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_S_start_free += __total_bytes;
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return __result ;
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return __result ;
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}
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}
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else if (__bytes_left >= __n)
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else if (__bytes_left >= __n)
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{
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{
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__nobjs = (int)(__bytes_left / __n);
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__nobjs = (int)(__bytes_left / __n);
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__total_bytes = __n * __nobjs;
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__total_bytes = __n * __nobjs;
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__result = _S_start_free;
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__result = _S_start_free;
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_S_start_free += __total_bytes;
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_S_start_free += __total_bytes;
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return __result;
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return __result;
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}
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}
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else
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else
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{
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{
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// Try to make use of the left-over piece.
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// Try to make use of the left-over piece.
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if (__bytes_left > 0)
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if (__bytes_left > 0)
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{
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{
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_Obj* volatile* __free_list = _M_get_free_list(__bytes_left);
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_Obj* volatile* __free_list = _M_get_free_list(__bytes_left);
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((_Obj*)(void*)_S_start_free)->_M_free_list_link = *__free_list;
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((_Obj*)(void*)_S_start_free)->_M_free_list_link = *__free_list;
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*__free_list = (_Obj*)(void*)_S_start_free;
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*__free_list = (_Obj*)(void*)_S_start_free;
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}
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}
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size_t __bytes_to_get = (2 * __total_bytes
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size_t __bytes_to_get = (2 * __total_bytes
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+ _M_round_up(_S_heap_size >> 4));
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+ _M_round_up(_S_heap_size >> 4));
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__try
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__try
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{
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{
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_S_start_free = static_cast<char*>(::operator new(__bytes_to_get));
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_S_start_free = static_cast<char*>(::operator new(__bytes_to_get));
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}
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}
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__catch(const std::bad_alloc&)
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__catch(const std::bad_alloc&)
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{
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{
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// Try to make do with what we have. That can't hurt. We
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// Try to make do with what we have. That can't hurt. We
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// do not try smaller requests, since that tends to result
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// do not try smaller requests, since that tends to result
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// in disaster on multi-process machines.
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// in disaster on multi-process machines.
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size_t __i = __n;
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size_t __i = __n;
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for (; __i <= (size_t) _S_max_bytes; __i += (size_t) _S_align)
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for (; __i <= (size_t) _S_max_bytes; __i += (size_t) _S_align)
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{
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{
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_Obj* volatile* __free_list = _M_get_free_list(__i);
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_Obj* volatile* __free_list = _M_get_free_list(__i);
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_Obj* __p = *__free_list;
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_Obj* __p = *__free_list;
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if (__p != 0)
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if (__p != 0)
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{
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{
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*__free_list = __p->_M_free_list_link;
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*__free_list = __p->_M_free_list_link;
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_S_start_free = (char*)__p;
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_S_start_free = (char*)__p;
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_S_end_free = _S_start_free + __i;
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_S_end_free = _S_start_free + __i;
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return _M_allocate_chunk(__n, __nobjs);
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return _M_allocate_chunk(__n, __nobjs);
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// Any leftover piece will eventually make it to the
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// Any leftover piece will eventually make it to the
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// right free list.
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// right free list.
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}
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}
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}
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}
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// What we have wasn't enough. Rethrow.
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// What we have wasn't enough. Rethrow.
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_S_start_free = _S_end_free = 0; // We have no chunk.
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_S_start_free = _S_end_free = 0; // We have no chunk.
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__throw_exception_again;
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__throw_exception_again;
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}
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}
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_S_heap_size += __bytes_to_get;
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_S_heap_size += __bytes_to_get;
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_S_end_free = _S_start_free + __bytes_to_get;
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_S_end_free = _S_start_free + __bytes_to_get;
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return _M_allocate_chunk(__n, __nobjs);
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return _M_allocate_chunk(__n, __nobjs);
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}
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}
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}
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}
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// Returns an object of size __n, and optionally adds to "size
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// Returns an object of size __n, and optionally adds to "size
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// __n"'s free list. We assume that __n is properly aligned. We
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// __n"'s free list. We assume that __n is properly aligned. We
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// hold the allocation lock.
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// hold the allocation lock.
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void*
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void*
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__pool_alloc_base::_M_refill(size_t __n)
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__pool_alloc_base::_M_refill(size_t __n)
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{
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{
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int __nobjs = 20;
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int __nobjs = 20;
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char* __chunk = _M_allocate_chunk(__n, __nobjs);
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char* __chunk = _M_allocate_chunk(__n, __nobjs);
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_Obj* volatile* __free_list;
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_Obj* volatile* __free_list;
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_Obj* __result;
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_Obj* __result;
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_Obj* __current_obj;
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_Obj* __current_obj;
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_Obj* __next_obj;
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_Obj* __next_obj;
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if (__nobjs == 1)
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if (__nobjs == 1)
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return __chunk;
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return __chunk;
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__free_list = _M_get_free_list(__n);
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__free_list = _M_get_free_list(__n);
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// Build free list in chunk.
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// Build free list in chunk.
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__result = (_Obj*)(void*)__chunk;
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__result = (_Obj*)(void*)__chunk;
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*__free_list = __next_obj = (_Obj*)(void*)(__chunk + __n);
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*__free_list = __next_obj = (_Obj*)(void*)(__chunk + __n);
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for (int __i = 1; ; __i++)
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for (int __i = 1; ; __i++)
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{
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{
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__current_obj = __next_obj;
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__current_obj = __next_obj;
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__next_obj = (_Obj*)(void*)((char*)__next_obj + __n);
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__next_obj = (_Obj*)(void*)((char*)__next_obj + __n);
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if (__nobjs - 1 == __i)
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if (__nobjs - 1 == __i)
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{
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{
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__current_obj->_M_free_list_link = 0;
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__current_obj->_M_free_list_link = 0;
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break;
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break;
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}
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}
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else
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else
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__current_obj->_M_free_list_link = __next_obj;
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__current_obj->_M_free_list_link = __next_obj;
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}
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}
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return __result;
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return __result;
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}
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}
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__pool_alloc_base::_Obj* volatile __pool_alloc_base::_S_free_list[_S_free_list_size];
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__pool_alloc_base::_Obj* volatile __pool_alloc_base::_S_free_list[_S_free_list_size];
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char* __pool_alloc_base::_S_start_free = 0;
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char* __pool_alloc_base::_S_start_free = 0;
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char* __pool_alloc_base::_S_end_free = 0;
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char* __pool_alloc_base::_S_end_free = 0;
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size_t __pool_alloc_base::_S_heap_size = 0;
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size_t __pool_alloc_base::_S_heap_size = 0;
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// Instantiations.
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// Instantiations.
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template class __pool_alloc<char>;
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template class __pool_alloc<char>;
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template class __pool_alloc<wchar_t>;
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template class __pool_alloc<wchar_t>;
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_GLIBCXX_END_NAMESPACE
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_GLIBCXX_END_NAMESPACE
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