--- /dev/null
+// Allocators -*- C++ -*-
+
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+// Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/*
+ * Copyright (c) 1996-1997
+ * Silicon Graphics Computer Systems, Inc.
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation. Silicon Graphics makes no
+ * representations about the suitability of this software for any
+ * purpose. It is provided "as is" without express or implied warranty.
+ */
+
+/** @file ext/pool_allocator.h
+ * This file is a GNU extension to the Standard C++ Library.
+ */
+
+#ifndef _POOL_ALLOCATOR_H
+#define _POOL_ALLOCATOR_H 1
+
+#include <bits/c++config.h>
+#include <cstdlib>
+#include <new>
+#include <bits/functexcept.h>
+#include <ext/atomicity.h>
+#include <ext/concurrence.h>
+#include <bits/move.h>
+
+_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
+
+ using std::size_t;
+ using std::ptrdiff_t;
+
+ /**
+ * @brief Base class for __pool_alloc.
+ *
+ * Uses various allocators to fulfill underlying requests (and makes as
+ * few requests as possible when in default high-speed pool mode).
+ *
+ * Important implementation properties:
+ * 0. If globally mandated, then allocate objects from new
+ * 1. If the clients request an object of size > _S_max_bytes, the resulting
+ * object will be obtained directly from new
+ * 2. In all other cases, we allocate an object of size exactly
+ * _S_round_up(requested_size). Thus the client has enough size
+ * information that we can return the object to the proper free list
+ * without permanently losing part of the object.
+ */
+ class __pool_alloc_base
+ {
+ protected:
+
+ enum { _S_align = 8 };
+ enum { _S_max_bytes = 128 };
+ enum { _S_free_list_size = (size_t)_S_max_bytes / (size_t)_S_align };
+
+ union _Obj
+ {
+ union _Obj* _M_free_list_link;
+ char _M_client_data[1]; // The client sees this.
+ };
+
+ static _Obj* volatile _S_free_list[_S_free_list_size];
+
+ // Chunk allocation state.
+ static char* _S_start_free;
+ static char* _S_end_free;
+ static size_t _S_heap_size;
+
+ size_t
+ _M_round_up(size_t __bytes)
+ { return ((__bytes + (size_t)_S_align - 1) & ~((size_t)_S_align - 1)); }
+
+ _Obj* volatile*
+ _M_get_free_list(size_t __bytes);
+
+ __mutex&
+ _M_get_mutex();
+
+ // Returns an object of size __n, and optionally adds to size __n
+ // free list.
+ void*
+ _M_refill(size_t __n);
+
+ // Allocates a chunk for nobjs of size size. nobjs may be reduced
+ // if it is inconvenient to allocate the requested number.
+ char*
+ _M_allocate_chunk(size_t __n, int& __nobjs);
+ };
+
+
+ /**
+ * @brief Allocator using a memory pool with a single lock.
+ * @ingroup allocators
+ */
+ template<typename _Tp>
+ class __pool_alloc : private __pool_alloc_base
+ {
+ private:
+ static _Atomic_word _S_force_new;
+
+ public:
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
+ typedef _Tp* pointer;
+ typedef const _Tp* const_pointer;
+ typedef _Tp& reference;
+ typedef const _Tp& const_reference;
+ typedef _Tp value_type;
+
+ template<typename _Tp1>
+ struct rebind
+ { typedef __pool_alloc<_Tp1> other; };
+
+ __pool_alloc() throw() { }
+
+ __pool_alloc(const __pool_alloc&) throw() { }
+
+ template<typename _Tp1>
+ __pool_alloc(const __pool_alloc<_Tp1>&) throw() { }
+
+ ~__pool_alloc() throw() { }
+
+ pointer
+ address(reference __x) const { return &__x; }
+
+ const_pointer
+ address(const_reference __x) const { return &__x; }
+
+ size_type
+ max_size() const throw()
+ { return size_t(-1) / sizeof(_Tp); }
+
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 402. wrong new expression in [some_] allocator::construct
+ void
+ construct(pointer __p, const _Tp& __val)
+ { ::new((void *)__p) _Tp(__val); }
+
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+ template<typename... _Args>
+ void
+ construct(pointer __p, _Args&&... __args)
+ { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
+#endif
+
+ void
+ destroy(pointer __p) { __p->~_Tp(); }
+
+ pointer
+ allocate(size_type __n, const void* = 0);
+
+ void
+ deallocate(pointer __p, size_type __n);
+ };
+
+ template<typename _Tp>
+ inline bool
+ operator==(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
+ { return true; }
+
+ template<typename _Tp>
+ inline bool
+ operator!=(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
+ { return false; }
+
+ template<typename _Tp>
+ _Atomic_word
+ __pool_alloc<_Tp>::_S_force_new;
+
+ template<typename _Tp>
+ _Tp*
+ __pool_alloc<_Tp>::allocate(size_type __n, const void*)
+ {
+ pointer __ret = 0;
+ if (__builtin_expect(__n != 0, true))
+ {
+ if (__builtin_expect(__n > this->max_size(), false))
+ std::__throw_bad_alloc();
+
+ // If there is a race through here, assume answer from getenv
+ // will resolve in same direction. Inspired by techniques
+ // to efficiently support threading found in basic_string.h.
+ if (_S_force_new == 0)
+ {
+ if (std::getenv("GLIBCXX_FORCE_NEW"))
+ __atomic_add_dispatch(&_S_force_new, 1);
+ else
+ __atomic_add_dispatch(&_S_force_new, -1);
+ }
+
+ const size_t __bytes = __n * sizeof(_Tp);
+ if (__bytes > size_t(_S_max_bytes) || _S_force_new > 0)
+ __ret = static_cast<_Tp*>(::operator new(__bytes));
+ else
+ {
+ _Obj* volatile* __free_list = _M_get_free_list(__bytes);
+
+ __scoped_lock sentry(_M_get_mutex());
+ _Obj* __restrict__ __result = *__free_list;
+ if (__builtin_expect(__result == 0, 0))
+ __ret = static_cast<_Tp*>(_M_refill(_M_round_up(__bytes)));
+ else
+ {
+ *__free_list = __result->_M_free_list_link;
+ __ret = reinterpret_cast<_Tp*>(__result);
+ }
+ if (__builtin_expect(__ret == 0, 0))
+ std::__throw_bad_alloc();
+ }
+ }
+ return __ret;
+ }
+
+ template<typename _Tp>
+ void
+ __pool_alloc<_Tp>::deallocate(pointer __p, size_type __n)
+ {
+ if (__builtin_expect(__n != 0 && __p != 0, true))
+ {
+ const size_t __bytes = __n * sizeof(_Tp);
+ if (__bytes > static_cast<size_t>(_S_max_bytes) || _S_force_new > 0)
+ ::operator delete(__p);
+ else
+ {
+ _Obj* volatile* __free_list = _M_get_free_list(__bytes);
+ _Obj* __q = reinterpret_cast<_Obj*>(__p);
+
+ __scoped_lock sentry(_M_get_mutex());
+ __q ->_M_free_list_link = *__free_list;
+ *__free_list = __q;
+ }
+ }
+ }
+
+_GLIBCXX_END_NAMESPACE
+
+#endif
projects / msp430-gcc.git / blobdiff