diff options
Diffstat (limited to 'contrib/src/boost/smart_ptr/detail/quick_allocator.hpp')
| -rw-r--r-- | contrib/src/boost/smart_ptr/detail/quick_allocator.hpp | 398 |
1 files changed, 199 insertions, 199 deletions
diff --git a/contrib/src/boost/smart_ptr/detail/quick_allocator.hpp b/contrib/src/boost/smart_ptr/detail/quick_allocator.hpp index 12dfb83..159bd5e 100644 --- a/contrib/src/boost/smart_ptr/detail/quick_allocator.hpp +++ b/contrib/src/boost/smart_ptr/detail/quick_allocator.hpp @@ -1,199 +1,199 @@ -#ifndef BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED
-#define BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED
-
-// MS compatible compilers support #pragma once
-
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
-# pragma once
-#endif
-
-//
-// detail/quick_allocator.hpp
-//
-// Copyright (c) 2003 David Abrahams
-// Copyright (c) 2003 Peter Dimov
-//
-// Distributed under the Boost Software License, Version 1.0. (See
-// accompanying file LICENSE_1_0.txt or copy at
-// http://www.boost.org/LICENSE_1_0.txt)
-//
-
-#include <boost/config.hpp>
-
-#include <boost/smart_ptr/detail/lightweight_mutex.hpp>
-#include <boost/type_traits/type_with_alignment.hpp>
-#include <boost/type_traits/alignment_of.hpp>
-
-#include <new> // ::operator new, ::operator delete
-#include <cstddef> // std::size_t
-
-namespace boost
-{
-
-namespace detail
-{
-
-template<unsigned size, unsigned align_> union freeblock
-{
- typedef typename boost::type_with_alignment<align_>::type aligner_type;
- aligner_type aligner;
- char bytes[size];
- freeblock * next;
-};
-
-template<unsigned size, unsigned align_> struct allocator_impl
-{
- typedef freeblock<size, align_> block;
-
- // It may seem odd to use such small pages.
- //
- // However, on a typical Windows implementation that uses
- // the OS allocator, "normal size" pages interact with the
- // "ordinary" operator new, slowing it down dramatically.
- //
- // 512 byte pages are handled by the small object allocator,
- // and don't interfere with ::new.
- //
- // The other alternative is to use much bigger pages (1M.)
- //
- // It is surprisingly easy to hit pathological behavior by
- // varying the page size. g++ 2.96 on Red Hat Linux 7.2,
- // for example, passionately dislikes 496. 512 seems OK.
-
-#if defined(BOOST_QA_PAGE_SIZE)
-
- enum { items_per_page = BOOST_QA_PAGE_SIZE / size };
-
-#else
-
- enum { items_per_page = 512 / size }; // 1048560 / size
-
-#endif
-
-#ifdef BOOST_HAS_THREADS
-
- static lightweight_mutex & mutex()
- {
- static freeblock< sizeof( lightweight_mutex ), boost::alignment_of< lightweight_mutex >::value > fbm;
- static lightweight_mutex * pm = new( &fbm ) lightweight_mutex;
- return *pm;
- }
-
- static lightweight_mutex * mutex_init;
-
-#endif
-
- static block * free;
- static block * page;
- static unsigned last;
-
- static inline void * alloc()
- {
-#ifdef BOOST_HAS_THREADS
- lightweight_mutex::scoped_lock lock( mutex() );
-#endif
- if(block * x = free)
- {
- free = x->next;
- return x;
- }
- else
- {
- if(last == items_per_page)
- {
- // "Listen to me carefully: there is no memory leak"
- // -- Scott Meyers, Eff C++ 2nd Ed Item 10
- page = ::new block[items_per_page];
- last = 0;
- }
-
- return &page[last++];
- }
- }
-
- static inline void * alloc(std::size_t n)
- {
- if(n != size) // class-specific new called for a derived object
- {
- return ::operator new(n);
- }
- else
- {
-#ifdef BOOST_HAS_THREADS
- lightweight_mutex::scoped_lock lock( mutex() );
-#endif
- if(block * x = free)
- {
- free = x->next;
- return x;
- }
- else
- {
- if(last == items_per_page)
- {
- page = ::new block[items_per_page];
- last = 0;
- }
-
- return &page[last++];
- }
- }
- }
-
- static inline void dealloc(void * pv)
- {
- if(pv != 0) // 18.4.1.1/13
- {
-#ifdef BOOST_HAS_THREADS
- lightweight_mutex::scoped_lock lock( mutex() );
-#endif
- block * pb = static_cast<block *>(pv);
- pb->next = free;
- free = pb;
- }
- }
-
- static inline void dealloc(void * pv, std::size_t n)
- {
- if(n != size) // class-specific delete called for a derived object
- {
- ::operator delete(pv);
- }
- else if(pv != 0) // 18.4.1.1/13
- {
-#ifdef BOOST_HAS_THREADS
- lightweight_mutex::scoped_lock lock( mutex() );
-#endif
- block * pb = static_cast<block *>(pv);
- pb->next = free;
- free = pb;
- }
- }
-};
-
-#ifdef BOOST_HAS_THREADS
-
-template<unsigned size, unsigned align_>
- lightweight_mutex * allocator_impl<size, align_>::mutex_init = &allocator_impl<size, align_>::mutex();
-
-#endif
-
-template<unsigned size, unsigned align_>
- freeblock<size, align_> * allocator_impl<size, align_>::free = 0;
-
-template<unsigned size, unsigned align_>
- freeblock<size, align_> * allocator_impl<size, align_>::page = 0;
-
-template<unsigned size, unsigned align_>
- unsigned allocator_impl<size, align_>::last = allocator_impl<size, align_>::items_per_page;
-
-template<class T>
-struct quick_allocator: public allocator_impl< sizeof(T), boost::alignment_of<T>::value >
-{
-};
-
-} // namespace detail
-
-} // namespace boost
-
-#endif // #ifndef BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED
+#ifndef BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED +#define BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED + +// MS compatible compilers support #pragma once + +#if defined(_MSC_VER) && (_MSC_VER >= 1020) +# pragma once +#endif + +// +// detail/quick_allocator.hpp +// +// Copyright (c) 2003 David Abrahams +// Copyright (c) 2003 Peter Dimov +// +// Distributed under the Boost Software License, Version 1.0. (See +// accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) +// + +#include <boost/config.hpp> + +#include <boost/smart_ptr/detail/lightweight_mutex.hpp> +#include <boost/type_traits/type_with_alignment.hpp> +#include <boost/type_traits/alignment_of.hpp> + +#include <new> // ::operator new, ::operator delete +#include <cstddef> // std::size_t + +namespace boost +{ + +namespace detail +{ + +template<unsigned size, unsigned align_> union freeblock +{ + typedef typename boost::type_with_alignment<align_>::type aligner_type; + aligner_type aligner; + char bytes[size]; + freeblock * next; +}; + +template<unsigned size, unsigned align_> struct allocator_impl +{ + typedef freeblock<size, align_> block; + + // It may seem odd to use such small pages. + // + // However, on a typical Windows implementation that uses + // the OS allocator, "normal size" pages interact with the + // "ordinary" operator new, slowing it down dramatically. + // + // 512 byte pages are handled by the small object allocator, + // and don't interfere with ::new. + // + // The other alternative is to use much bigger pages (1M.) + // + // It is surprisingly easy to hit pathological behavior by + // varying the page size. g++ 2.96 on Red Hat Linux 7.2, + // for example, passionately dislikes 496. 512 seems OK. + +#if defined(BOOST_QA_PAGE_SIZE) + + enum { items_per_page = BOOST_QA_PAGE_SIZE / size }; + +#else + + enum { items_per_page = 512 / size }; // 1048560 / size + +#endif + +#ifdef BOOST_HAS_THREADS + + static lightweight_mutex & mutex() + { + static freeblock< sizeof( lightweight_mutex ), boost::alignment_of< lightweight_mutex >::value > fbm; + static lightweight_mutex * pm = new( &fbm ) lightweight_mutex; + return *pm; + } + + static lightweight_mutex * mutex_init; + +#endif + + static block * free; + static block * page; + static unsigned last; + + static inline void * alloc() + { +#ifdef BOOST_HAS_THREADS + lightweight_mutex::scoped_lock lock( mutex() ); +#endif + if(block * x = free) + { + free = x->next; + return x; + } + else + { + if(last == items_per_page) + { + // "Listen to me carefully: there is no memory leak" + // -- Scott Meyers, Eff C++ 2nd Ed Item 10 + page = ::new block[items_per_page]; + last = 0; + } + + return &page[last++]; + } + } + + static inline void * alloc(std::size_t n) + { + if(n != size) // class-specific new called for a derived object + { + return ::operator new(n); + } + else + { +#ifdef BOOST_HAS_THREADS + lightweight_mutex::scoped_lock lock( mutex() ); +#endif + if(block * x = free) + { + free = x->next; + return x; + } + else + { + if(last == items_per_page) + { + page = ::new block[items_per_page]; + last = 0; + } + + return &page[last++]; + } + } + } + + static inline void dealloc(void * pv) + { + if(pv != 0) // 18.4.1.1/13 + { +#ifdef BOOST_HAS_THREADS + lightweight_mutex::scoped_lock lock( mutex() ); +#endif + block * pb = static_cast<block *>(pv); + pb->next = free; + free = pb; + } + } + + static inline void dealloc(void * pv, std::size_t n) + { + if(n != size) // class-specific delete called for a derived object + { + ::operator delete(pv); + } + else if(pv != 0) // 18.4.1.1/13 + { +#ifdef BOOST_HAS_THREADS + lightweight_mutex::scoped_lock lock( mutex() ); +#endif + block * pb = static_cast<block *>(pv); + pb->next = free; + free = pb; + } + } +}; + +#ifdef BOOST_HAS_THREADS + +template<unsigned size, unsigned align_> + lightweight_mutex * allocator_impl<size, align_>::mutex_init = &allocator_impl<size, align_>::mutex(); + +#endif + +template<unsigned size, unsigned align_> + freeblock<size, align_> * allocator_impl<size, align_>::free = 0; + +template<unsigned size, unsigned align_> + freeblock<size, align_> * allocator_impl<size, align_>::page = 0; + +template<unsigned size, unsigned align_> + unsigned allocator_impl<size, align_>::last = allocator_impl<size, align_>::items_per_page; + +template<class T> +struct quick_allocator: public allocator_impl< sizeof(T), boost::alignment_of<T>::value > +{ +}; + +} // namespace detail + +} // namespace boost + +#endif // #ifndef BOOST_SMART_PTR_DETAIL_QUICK_ALLOCATOR_HPP_INCLUDED |