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Re: Final patch (Re: [Patch] bitmap_allocator.)
On Thu, 2004-10-14 at 15:48, Paolo Carlini wrote:
> Paolo Carlini wrote:
>
> > Thank you. I'm going to test it again on x86/x86_64/ia64.
>
> Ok, the below is what I'd like to commit later today.
>
> Built and tested x86/x86_64/ia64-linux, --enable-libstdcxx-allocator=bitmap,
> 1 fail, pthread7-rope.cc (+ warnings, expecially for std::list, on
> ia64); also
> double checked that x86/x86_64 are still ok when default configured.
What does the fail signify? You mentioned something about the
allocator's destructor being faulty, but I did not quite understand.
>
> Paolo.
>
> ///////////////
>
> ______________________________________________________________________
>
> 2004-10-14 Dhruv Matani <dhruvbird@gmx.net>
>
> * ext/bitmap_allocator.h: Clean-up add/remove functions.
> * src/bitmap_allocator.cc: New file. Contains the out-of-line
> function definitions, static initialization of variables, and
> explicit instantiations needed for the allocator.
> * src/Makefile.am: Add.
> * src/Makefile.in: Regenerate.
> * config/linker.map.gnu: Add the necessary symbols.
>
> ______________________________________________________________________
>
> diff -urN libstdc++-v3-orig/config/linker-map.gnu libstdc++-v3/config/linker-map.gnu
> --- libstdc++-v3-orig/config/linker-map.gnu 2004-10-12 10:19:29.000000000 +0200
> +++ libstdc++-v3/config/linker-map.gnu 2004-10-14 11:16:37.000000000 +0200
> @@ -270,7 +270,12 @@
> _ZN9__gnu_cxx6__poolILb[01]EE16_M_reserve_blockE[jm][jm];
> _ZN9__gnu_cxx6__poolILb[01]EE16_M_reclaim_blockEPc[jm];
> _ZN9__gnu_cxx6__poolILb[01]EE10_M_destroyEv;
> -
> +
> + _ZN9__gnu_cxx9free_list12_S_free_listE;
> + _ZN9__gnu_cxx9free_list12_S_bfl_mutexE;
> + _ZN9__gnu_cxx9free_list6_M_getEj;
> + _ZN9__gnu_cxx9free_list8_M_clearEv;
> +
> # stub functions from libmath
> acosf;
> acosl;
> diff -urN libstdc++-v3-orig/include/ext/bitmap_allocator.h libstdc++-v3/include/ext/bitmap_allocator.h
> --- libstdc++-v3-orig/include/ext/bitmap_allocator.h 2004-03-24 19:27:43.000000000 +0100
> +++ libstdc++-v3/include/ext/bitmap_allocator.h 2004-10-14 11:16:37.000000000 +0200
> @@ -1,4 +1,4 @@
> -// Bitmapped Allocator. -*- C++ -*-
> +// Bitmap Allocator. -*- C++ -*-
>
> // Copyright (C) 2004 Free Software Foundation, Inc.
> //
> @@ -27,53 +27,67 @@
> // invalidate any other reasons why the executable file might be covered by
> // the GNU General Public License.
>
> +/** @file ext/bitmap_allocator.h
> + * This file is a GNU extension to the Standard C++ Library.
> + * You should only include this header if you are using GCC 3 or later.
> + */
>
> -
> -#if !defined _BITMAP_ALLOCATOR_H
> +#ifndef _BITMAP_ALLOCATOR_H
> #define _BITMAP_ALLOCATOR_H 1
>
> +// For std::size_t, and ptrdiff_t.
> #include <cstddef>
> -//For std::size_t, and ptrdiff_t.
> +
> +// For std::pair.
> #include <utility>
> -//For std::pair.
> -#include <algorithm>
> -//std::find_if, and std::lower_bound.
> -#include <vector>
> -//For the free list of exponentially growing memory blocks. At max,
> -//size of the vector should be not more than the number of bits in an
> -//integer or an unsigned integer.
> +
> +// For greater_equal, and less_equal.
> #include <functional>
> -//For greater_equal, and less_equal.
> +
> +// For operator new.
> #include <new>
> -//For operator new.
> +
> +// For __gthread_mutex_t, __gthread_mutex_lock and __gthread_mutex_unlock.
> #include <bits/gthr.h>
> -//For __gthread_mutex_t, __gthread_mutex_lock and __gthread_mutex_unlock.
> -#include <ext/new_allocator.h>
> -//For __gnu_cxx::new_allocator for std::vector.
>
> +// Define this to enable error checking withing the allocator
> +// itself(to debug the allocator itself).
> +//#define _BALLOC_SANITY_CHECK
> +
> +#if defined _BALLOC_SANITY_CHECK
> #include <cassert>
> -#define NDEBUG
> +#define _BALLOC_ASSERT(_EXPR) assert(_EXPR)
> +#else
> +#define _BALLOC_ASSERT(_EXPR)
> +#endif
>
> -//#define CHECK_FOR_ERRORS
> -//#define __CPU_HAS_BACKWARD_BRANCH_PREDICTION
>
> namespace __gnu_cxx
> {
> - namespace {
> #if defined __GTHREADS
> + namespace
> + {
> + // If true, then the application being compiled will be using
> + // threads, so use mutexes as a synchronization primitive, else do
> + // no use any synchronization primitives.
> bool const __threads_enabled = __gthread_active_p();
> -#endif
> -
> }
> +#endif
>
> #if defined __GTHREADS
> - class _Mutex {
> + // _Mutex is an OO-Wrapper for __gthread_mutex_t. It does not allow
> + // you to copy or assign an already initialized mutex. This is used
> + // merely as a convenience for the locking classes.
> + class _Mutex
> + {
> __gthread_mutex_t _M_mut;
> - //Prevent Copying and assignment.
> - _Mutex (_Mutex const&);
> - _Mutex& operator= (_Mutex const&);
> +
> + // Prevent Copying and assignment.
> + _Mutex(_Mutex const&);
> + _Mutex& operator=(_Mutex const&);
> +
> public:
> - _Mutex ()
> + _Mutex()
> {
> if (__threads_enabled)
> {
> @@ -85,24 +99,38 @@
> #endif
> }
> }
> - ~_Mutex ()
> +
> + ~_Mutex()
> {
> - //Gthreads does not define a Mutex Destruction Function.
> + // Gthreads does not define a Mutex Destruction Function.
> }
> - __gthread_mutex_t *_M_get() { return &_M_mut; }
> +
> + __gthread_mutex_t*
> + _M_get() { return &_M_mut; }
> };
>
> - class _Lock {
> + // _Lock is a simple manual lokcing class which allows you to
> + // manually lock and unlock a mutex associated with the lock. There
> + // is not automatic locking or unlocking happening without the
> + // programmer's explicit instructions. This class unlocks the mutex
> + // ONLY if it has not been locked. However, this check does not
> + // apply for lokcing, and wayward use may cause dead-locks.
> + class _Lock
> + {
> _Mutex* _M_pmt;
> bool _M_locked;
> - //Prevent Copying and assignment.
> - _Lock (_Lock const&);
> - _Lock& operator= (_Lock const&);
> +
> + // Prevent Copying and assignment.
> + _Lock(_Lock const&);
> + _Lock& operator=(_Lock const&);
> +
> public:
> _Lock(_Mutex* __mptr)
> - : _M_pmt(__mptr), _M_locked(false)
> - { this->_M_lock(); }
> - void _M_lock()
> + : _M_pmt(__mptr), _M_locked(false)
> + { }
> +
> + void
> + _M_lock()
> {
> if (__threads_enabled)
> {
> @@ -110,7 +138,9 @@
> __gthread_mutex_lock(_M_pmt->_M_get());
> }
> }
> - void _M_unlock()
> +
> + void
> + _M_unlock()
> {
> if (__threads_enabled)
> {
> @@ -121,739 +151,1015 @@
> }
> }
> }
> - ~_Lock() { this->_M_unlock(); }
> +
> + ~_Lock() { }
> };
> -#endif
> -
> -
>
> - namespace __aux_balloc {
> - static const unsigned int _Bits_Per_Byte = 8;
> - static const unsigned int _Bits_Per_Block = sizeof(unsigned int) * _Bits_Per_Byte;
> + // _Auto_Lock locks the associated mutex on construction, and
> + // unlocks on it's destruction. There are no checks performed, and
> + // this calss follows the RAII principle.
> + class _Auto_Lock
> + {
> + _Mutex* _M_pmt;
> + // Prevent Copying and assignment.
> + _Auto_Lock(_Auto_Lock const&);
> + _Auto_Lock& operator=(_Auto_Lock const&);
>
> - template <typename _Addr_Pair_t>
> - inline size_t __balloc_num_blocks (_Addr_Pair_t __ap)
> + void
> + _M_lock()
> {
> - return (__ap.second - __ap.first) + 1;
> + if (__threads_enabled)
> + __gthread_mutex_lock(_M_pmt->_M_get());
> }
>
> - template <typename _Addr_Pair_t>
> - inline size_t __balloc_num_bit_maps (_Addr_Pair_t __ap)
> + void
> + _M_unlock()
> {
> - return __balloc_num_blocks(__ap) / _Bits_Per_Block;
> + if (__threads_enabled)
> + __gthread_mutex_unlock(_M_pmt->_M_get());
> }
>
> - //T should be a pointer type.
> - template <typename _Tp>
> - class _Inclusive_between : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> {
> - typedef _Tp pointer;
> - pointer _M_ptr_value;
> - typedef typename std::pair<_Tp, _Tp> _Block_pair;
> + public:
> + _Auto_Lock(_Mutex* __mptr) : _M_pmt(__mptr)
> + { this->_M_lock(); }
>
> - public:
> - _Inclusive_between (pointer __ptr) : _M_ptr_value(__ptr) { }
> - bool operator () (_Block_pair __bp) const throw ()
> + ~_Auto_Lock() { this->_M_unlock(); }
> + };
> +#endif
> +
> + namespace balloc
> + {
> + // __mini_vector<> is to be used only for built-in types or
> + // PODs. It is a stripped down version of the full-fledged
> + // std::vector<>. Noteable differences are:
> + //
> + // 1. Not all accessor functions are present.
> + // 2. Used ONLY for PODs.
> + // 3. No Allocator template argument. Uses ::operator new() to get
> + // memory, and ::operator delete() to free it.
> + template<typename _Tp>
> + class __mini_vector
> {
> - if (std::less_equal<pointer> ()(_M_ptr_value, __bp.second) &&
> - std::greater_equal<pointer> ()(_M_ptr_value, __bp.first))
> - return true;
> - else
> - return false;
> - }
> - };
> -
> - //Used to pass a Functor to functions by reference.
> - template <typename _Functor>
> - class _Functor_Ref :
> - public std::unary_function<typename _Functor::argument_type, typename _Functor::result_type> {
> - _Functor& _M_fref;
> -
> - public:
> - typedef typename _Functor::argument_type argument_type;
> - typedef typename _Functor::result_type result_type;
> + __mini_vector(const __mini_vector&);
> + __mini_vector& operator=(const __mini_vector&);
>
> - _Functor_Ref (_Functor& __fref) : _M_fref(__fref) { }
> - result_type operator() (argument_type __arg) { return _M_fref (__arg); }
> - };
> + public:
> + typedef _Tp value_type;
> + typedef _Tp* pointer;
> + typedef _Tp& reference;
> + typedef const _Tp& const_reference;
> + typedef std::size_t size_type;
> + typedef std::ptrdiff_t difference_type;
> + typedef pointer iterator;
> +
> + private:
> + pointer _M_start;
> + pointer _M_finish;
> + pointer _M_end_of_storage;
> +
> + size_type
> + _M_space_left() const throw()
> + { return _M_end_of_storage - _M_finish; }
> +
> + pointer
> + allocate(size_type __n)
> + { return static_cast<pointer>(::operator new(__n * sizeof(_Tp))); }
> +
> + void
> + deallocate(pointer __p, size_type)
> + { ::operator delete(__p); }
> +
> + public:
> + // Members used: size(), push_back(), pop_back(),
> + // insert(iterator, const_reference), erase(iterator),
> + // begin(), end(), back(), operator[].
> +
> + __mini_vector() : _M_start(0), _M_finish(0),
> + _M_end_of_storage(0)
> + { }
>
> + ~__mini_vector()
> + {
> + if (this->_M_start)
> + {
> + this->deallocate(this->_M_start, this->_M_end_of_storage
> + - this->_M_start);
> + }
> + }
>
> - //T should be a pointer type, and A is the Allocator for the vector.
> - template <typename _Tp, typename _Alloc>
> - class _Ffit_finder
> - : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> {
> - typedef typename std::vector<std::pair<_Tp, _Tp>, _Alloc> _BPVector;
> - typedef typename _BPVector::difference_type _Counter_type;
> - typedef typename std::pair<_Tp, _Tp> _Block_pair;
> + size_type
> + size() const throw()
> + { return _M_finish - _M_start; }
> +
> + iterator
> + begin() const throw()
> + { return this->_M_start; }
> +
> + iterator
> + end() const throw()
> + { return this->_M_finish; }
> +
> + reference
> + back() const throw()
> + { return *(this->end() - 1); }
> +
> + reference
> + operator[](const size_type __pos) const throw()
> + { return this->_M_start[__pos]; }
>
> - unsigned int *_M_pbitmap;
> - unsigned int _M_data_offset;
> + void
> + insert(iterator __pos, const_reference __x);
>
> - public:
> - _Ffit_finder ()
> - : _M_pbitmap (0), _M_data_offset (0)
> - { }
> + void
> + push_back(const_reference __x)
> + {
> + if (this->_M_space_left())
> + {
> + *this->end() = __x;
> + ++this->_M_finish;
> + }
> + else
> + this->insert(this->end(), __x);
> + }
>
> - bool operator() (_Block_pair __bp) throw()
> + void
> + pop_back() throw()
> + { --this->_M_finish; }
> +
> + void
> + erase(iterator __pos) throw();
> +
> + void
> + clear() throw()
> + { this->_M_finish = this->_M_start; }
> + };
> +
> + // Out of line function definitions.
> + template<typename _Tp>
> + void __mini_vector<_Tp>::
> + insert(iterator __pos, const_reference __x)
> {
> - //Set the _rover to the last unsigned integer, which is the
> - //bitmap to the first free block. Thus, the bitmaps are in exact
> - //reverse order of the actual memory layout. So, we count down
> - //the bimaps, which is the same as moving up the memory.
> -
> - //If the used count stored at the start of the Bit Map headers
> - //is equal to the number of Objects that the current Block can
> - //store, then there is definitely no space for another single
> - //object, so just return false.
> - _Counter_type __diff = __gnu_cxx::__aux_balloc::__balloc_num_bit_maps (__bp);
> -
> - assert (*(reinterpret_cast<unsigned int*>(__bp.first) - (__diff + 1)) <=
> - __gnu_cxx::__aux_balloc::__balloc_num_blocks (__bp));
> -
> - if (*(reinterpret_cast<unsigned int*>(__bp.first) - (__diff + 1)) ==
> - __gnu_cxx::__aux_balloc::__balloc_num_blocks (__bp))
> - return false;
> + if (this->_M_space_left())
> + {
> + size_type __to_move = this->_M_finish - __pos;
> + iterator __dest = this->end();
> + iterator __src = this->end() - 1;
>
> - unsigned int *__rover = reinterpret_cast<unsigned int*>(__bp.first) - 1;
> - for (_Counter_type __i = 0; __i < __diff; ++__i)
> + ++this->_M_finish;
> + while (__to_move)
> + {
> + *__dest = *__src;
> + --__dest; --__src; --__to_move;
> + }
> + *__pos = __x;
> + }
> + else
> {
> - _M_data_offset = __i;
> - if (*__rover)
> + size_type __new_size = this->size() ? this->size() * 2 : 1;
> + iterator __new_start = this->allocate(__new_size);
> + iterator __first = this->begin();
> + iterator __start = __new_start;
> + while (__first != __pos)
> {
> - _M_pbitmap = __rover;
> - return true;
> + *__start = *__first;
> + ++__start; ++__first;
> }
> - --__rover;
> + *__start = __x;
> + ++__start;
> + while (__first != this->end())
> + {
> + *__start = *__first;
> + ++__start; ++__first;
> + }
> + if (this->_M_start)
> + this->deallocate(this->_M_start, this->size());
> +
> + this->_M_start = __new_start;
> + this->_M_finish = __start;
> + this->_M_end_of_storage = this->_M_start + __new_size;
> }
> - return false;
> - }
> -
> - unsigned int *_M_get () { return _M_pbitmap; }
> - unsigned int _M_offset () { return _M_data_offset * _Bits_Per_Block; }
> - };
> -
> - //T should be a pointer type.
> - template <typename _Tp, typename _Alloc>
> - class _Bit_map_counter {
> -
> - typedef typename std::vector<std::pair<_Tp, _Tp>, _Alloc> _BPVector;
> - typedef typename _BPVector::size_type _Index_type;
> - typedef _Tp pointer;
> -
> - _BPVector& _M_vbp;
> - unsigned int *_M_curr_bmap;
> - unsigned int *_M_last_bmap_in_block;
> - _Index_type _M_curr_index;
> -
> - public:
> - //Use the 2nd parameter with care. Make sure that such an entry
> - //exists in the vector before passing that particular index to
> - //this ctor.
> - _Bit_map_counter (_BPVector& Rvbp, int __index = -1)
> - : _M_vbp(Rvbp)
> - {
> - this->_M_reset(__index);
> }
> -
> - void _M_reset (int __index = -1) throw()
> +
> + template<typename _Tp>
> + void __mini_vector<_Tp>::
> + erase(iterator __pos) throw()
> {
> - if (__index == -1)
> + while (__pos + 1 != this->end())
> {
> - _M_curr_bmap = 0;
> - _M_curr_index = (_Index_type)-1;
> - return;
> + *__pos = __pos[1];
> + ++__pos;
> }
> + --this->_M_finish;
> + }
>
> - _M_curr_index = __index;
> - _M_curr_bmap = reinterpret_cast<unsigned int*>(_M_vbp[_M_curr_index].first) - 1;
>
> - assert (__index <= (int)_M_vbp.size() - 1);
> -
> - _M_last_bmap_in_block = _M_curr_bmap -
> - ((_M_vbp[_M_curr_index].second - _M_vbp[_M_curr_index].first + 1) / _Bits_Per_Block - 1);
> - }
> -
> - //Dangerous Function! Use with extreme care. Pass to this
> - //function ONLY those values that are known to be correct,
> - //otherwise this will mess up big time.
> - void _M_set_internal_bit_map (unsigned int *__new_internal_marker) throw()
> + template<typename _Tp>
> + struct __mv_iter_traits
> {
> - _M_curr_bmap = __new_internal_marker;
> - }
> -
> - bool _M_finished () const throw()
> + typedef typename _Tp::value_type value_type;
> + typedef typename _Tp::difference_type difference_type;
> + };
> +
> + template<typename _Tp>
> + struct __mv_iter_traits<_Tp*>
> {
> - return (_M_curr_bmap == 0);
> - }
> -
> - _Bit_map_counter& operator++ () throw()
> + typedef _Tp value_type;
> + typedef std::ptrdiff_t difference_type;
> + };
> +
> + enum
> + {
> + bits_per_byte = 8,
> + bits_per_block = sizeof(unsigned int) * bits_per_byte
> + };
> +
> + template<typename _ForwardIterator, typename _Tp, typename _Compare>
> + _ForwardIterator
> + __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
> + const _Tp& __val, _Compare __comp)
> {
> - if (_M_curr_bmap == _M_last_bmap_in_block)
> + typedef typename __mv_iter_traits<_ForwardIterator>::value_type
> + _ValueType;
> + typedef typename __mv_iter_traits<_ForwardIterator>::difference_type
> + _DistanceType;
> +
> + _DistanceType __len = __last - __first;
> + _DistanceType __half;
> + _ForwardIterator __middle;
> +
> + while (__len > 0)
> {
> - if (++_M_curr_index == _M_vbp.size())
> + __half = __len >> 1;
> + __middle = __first;
> + __middle += __half;
> + if (__comp(*__middle, __val))
> {
> - _M_curr_bmap = 0;
> + __first = __middle;
> + ++__first;
> + __len = __len - __half - 1;
> }
> else
> - {
> - this->_M_reset (_M_curr_index);
> - }
> - }
> - else
> - {
> - --_M_curr_bmap;
> + __len = __half;
> }
> - return *this;
> + return __first;
> }
> -
> - unsigned int *_M_get ()
> +
> + template<typename _InputIterator, typename _Predicate>
> + inline _InputIterator
> + __find_if(_InputIterator __first, _InputIterator __last, _Predicate __p)
> {
> - return _M_curr_bmap;
> + while (__first != __last && !__p(*__first))
> + ++__first;
> + return __first;
> }
> +
> + template<typename _AddrPair>
> + inline size_t
> + __num_blocks(_AddrPair __ap)
> + { return (__ap.second - __ap.first) + 1; }
> +
> + template<typename _AddrPair>
> + inline size_t
> + __num_bitmaps(_AddrPair __ap)
> + { return __num_blocks(__ap) / bits_per_block; }
> +
> + // _Tp should be a pointer type.
> + template<typename _Tp>
> + class _Inclusive_between
> + : public std::unary_function<typename std::pair<_Tp, _Tp>, bool>
> + {
> + typedef _Tp pointer;
> + pointer _M_ptr_value;
> + typedef typename std::pair<_Tp, _Tp> _Block_pair;
> +
> + public:
> + _Inclusive_between(pointer __ptr) : _M_ptr_value(__ptr)
> + { }
> +
> + bool
> + operator()(_Block_pair __bp) const throw()
> + {
> + if (std::less_equal<pointer>()(_M_ptr_value, __bp.second)
> + && std::greater_equal<pointer>()(_M_ptr_value, __bp.first))
> + return true;
> + else
> + return false;
> + }
> + };
> +
> + // Used to pass a Functor to functions by reference.
> + template<typename _Functor>
> + class _Functor_Ref
> + : public std::unary_function<typename _Functor::argument_type,
> + typename _Functor::result_type>
> + {
> + _Functor& _M_fref;
> +
> + public:
> + typedef typename _Functor::argument_type argument_type;
> + typedef typename _Functor::result_type result_type;
> +
> + _Functor_Ref(_Functor& __fref) : _M_fref(__fref)
> + { }
> +
> + result_type
> + operator()(argument_type __arg)
> + { return _M_fref(__arg); }
> + };
> +
> + // _Tp should be a pointer type, and _Alloc is the Allocator for
> + // the vector.
> + template<typename _Tp>
> + class _Ffit_finder
> + : public std::unary_function<typename std::pair<_Tp, _Tp>, bool>
> + {
> + typedef typename std::pair<_Tp, _Tp> _Block_pair;
> + typedef typename balloc::__mini_vector<_Block_pair> _BPVector;
> + typedef typename _BPVector::difference_type _Counter_type;
> +
> + unsigned int* _M_pbitmap;
> + unsigned int _M_data_offset;
> +
> + public:
> + _Ffit_finder() : _M_pbitmap(0), _M_data_offset(0)
> + { }
> +
> + bool
> + operator()(_Block_pair __bp) throw()
> + {
> + // Set the _rover to the last unsigned integer, which is the
> + // bitmap to the first free block. Thus, the bitmaps are in exact
> + // reverse order of the actual memory layout. So, we count down
> + // the bimaps, which is the same as moving up the memory.
> +
> + // If the used count stored at the start of the Bit Map headers
> + // is equal to the number of Objects that the current Block can
> + // store, then there is definitely no space for another single
> + // object, so just return false.
> + _Counter_type __diff =
> + __gnu_cxx::balloc::__num_bitmaps(__bp);
> +
> + if (*reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>(__bp.first) - (sizeof(unsigned int) *
> + (__diff+1)))
> + == __gnu_cxx::balloc::__num_blocks(__bp))
> + return false;
> +
> + unsigned int* __rover = reinterpret_cast<unsigned int*>(__bp.first) - 1;
> +
> + for (_Counter_type __i = 0; __i < __diff; ++__i)
> + {
> + _M_data_offset = __i;
> + if (*__rover)
> + {
> + _M_pbitmap = __rover;
> + return true;
> + }
> + --__rover;
> + }
> + return false;
> + }
> +
>
> - pointer _M_base () { return _M_vbp[_M_curr_index].first; }
> - unsigned int _M_offset ()
> + unsigned int*
> + _M_get() const throw()
> + { return _M_pbitmap; }
> +
> + unsigned int
> + _M_offset() const throw()
> + { return _M_data_offset * bits_per_block; }
> + };
> +
> +
> +
> + // _Tp should be a pointer type.
> + template<typename _Tp>
> + class _Bitmap_counter
> {
> - return _Bits_Per_Block * ((reinterpret_cast<unsigned int*>(this->_M_base()) - _M_curr_bmap) - 1);
> - }
> + typedef typename balloc::__mini_vector<typename std::pair<_Tp, _Tp> >
> + _BPVector;
> + typedef typename _BPVector::size_type _Index_type;
> + typedef _Tp pointer;
>
> - unsigned int _M_where () { return _M_curr_index; }
> - };
> - }
> + _BPVector& _M_vbp;
> + unsigned int* _M_curr_bmap;
> + unsigned int* _M_last_bmap_in_block;
> + _Index_type _M_curr_index;
> +
> + public:
> + // Use the 2nd parameter with care. Make sure that such an
> + // entry exists in the vector before passing that particular
> + // index to this ctor.
> + _Bitmap_counter(_BPVector& Rvbp, int __index = -1) : _M_vbp(Rvbp)
> + { this->_M_reset(__index); }
> +
> + void
> + _M_reset(int __index = -1) throw()
> + {
> + if (__index == -1)
> + {
> + _M_curr_bmap = 0;
> + _M_curr_index = static_cast<_Index_type>(-1);
> + return;
> + }
>
> - //Generic Version of the bsf instruction.
> - typedef unsigned int _Bit_map_type;
> - static inline unsigned int _Bit_scan_forward (register _Bit_map_type __num)
> - {
> - return static_cast<unsigned int>(__builtin_ctz(__num));
> - }
> + _M_curr_index = __index;
> + _M_curr_bmap = reinterpret_cast<unsigned int*>
> + (_M_vbp[_M_curr_index].first) - 1;
>
> - struct _OOM_handler {
> - static std::new_handler _S_old_handler;
> - static bool _S_handled_oom;
> - typedef void (*_FL_clear_proc)(void);
> - static _FL_clear_proc _S_oom_fcp;
> + _BALLOC_ASSERT(__index <= (int)_M_vbp.size() - 1);
> +
> + _M_last_bmap_in_block = _M_curr_bmap
> + - ((_M_vbp[_M_curr_index].second
> + - _M_vbp[_M_curr_index].first + 1)
> + / bits_per_block - 1);
> + }
>
> - _OOM_handler (_FL_clear_proc __fcp)
> - {
> - _S_oom_fcp = __fcp;
> - _S_old_handler = std::set_new_handler (_S_handle_oom_proc);
> - _S_handled_oom = false;
> - }
> + // Dangerous Function! Use with extreme care. Pass to this
> + // function ONLY those values that are known to be correct,
> + // otherwise this will mess up big time.
> + void
> + _M_set_internal_bitmap(unsigned int* __new_internal_marker) throw()
> + { _M_curr_bmap = __new_internal_marker; }
> +
> + bool
> + _M_finished() const throw()
> + { return(_M_curr_bmap == 0); }
> +
> + _Bitmap_counter&
> + operator++() throw()
> + {
> + if (_M_curr_bmap == _M_last_bmap_in_block)
> + {
> + if (++_M_curr_index == _M_vbp.size())
> + _M_curr_bmap = 0;
> + else
> + this->_M_reset(_M_curr_index);
> + }
> + else
> + --_M_curr_bmap;
> + return *this;
> + }
> +
> + unsigned int*
> + _M_get() const throw()
> + { return _M_curr_bmap; }
> +
> + pointer
> + _M_base() const throw()
> + { return _M_vbp[_M_curr_index].first; }
>
> - static void _S_handle_oom_proc()
> - {
> - _S_oom_fcp();
> - std::set_new_handler (_S_old_handler);
> - _S_handled_oom = true;
> - }
> + unsigned int
> + _M_offset() const throw()
> + {
> + return bits_per_block
> + * ((reinterpret_cast<unsigned int*>(this->_M_base())
> + - _M_curr_bmap) - 1);
> + }
> +
> + unsigned int
> + _M_where() const throw()
> + { return _M_curr_index; }
> + };
>
> - ~_OOM_handler ()
> + inline void
> + __bit_allocate(unsigned int* __pbmap, unsigned int __pos) throw()
> {
> - if (!_S_handled_oom)
> - std::set_new_handler (_S_old_handler);
> + unsigned int __mask = 1 << __pos;
> + __mask = ~__mask;
> + *__pbmap &= __mask;
> }
> - };
> -
> - std::new_handler _OOM_handler::_S_old_handler;
> - bool _OOM_handler::_S_handled_oom = false;
> - _OOM_handler::_FL_clear_proc _OOM_handler::_S_oom_fcp = 0;
>
> + inline void
> + __bit_free(unsigned int* __pbmap, unsigned int __pos) throw()
> + {
> + unsigned int __mask = 1 << __pos;
> + *__pbmap |= __mask;
> + }
> + } // namespace balloc
>
> - class _BA_free_list_store {
> - struct _LT_pointer_compare {
> - template <typename _Tp>
> - bool operator() (_Tp* __pt, _Tp const& __crt) const throw()
> - {
> - return *__pt < __crt;
> - }
> + // Generic Version of the bsf instruction.
> + inline unsigned int
> + _Bit_scan_forward(register unsigned int __num)
> + { return static_cast<unsigned int>(__builtin_ctz(__num)); }
> +
> + class free_list
> + {
> + typedef unsigned int* value_type;
> + typedef balloc::__mini_vector<value_type> vector_type;
> + typedef vector_type::iterator iterator;
> +
> + struct _LT_pointer_compare
> + {
> + bool
> + operator()(const unsigned int* __pui, const unsigned int __cui) const throw()
> + { return *__pui < __cui; }
> };
>
> -#if defined __GTHREADS
> +#if defined __GTHREADS
> static _Mutex _S_bfl_mutex;
> #endif
> - static std::vector<unsigned int*> _S_free_list;
> - typedef std::vector<unsigned int*>::iterator _FLIter;
> -
> - static void _S_validate_free_list(unsigned int *__addr) throw()
> + static vector_type _S_free_list;
> +
> + void
> + _M_validate(unsigned int* __addr) throw()
> {
> const unsigned int __max_size = 64;
> if (_S_free_list.size() >= __max_size)
> {
> - //Ok, the threshold value has been reached.
> - //We determine which block to remove from the list of free
> - //blocks.
> + // Ok, the threshold value has been reached. We determine
> + // which block to remove from the list of free blocks.
> if (*__addr >= *_S_free_list.back())
> {
> - //Ok, the new block is greater than or equal to the last
> - //block in the list of free blocks. We just free the new
> - //block.
> - operator delete((void*)__addr);
> + // Ok, the new block is greater than or equal to the
> + // last block in the list of free blocks. We just free
> + // the new block.
> + operator delete(static_cast<void*>(__addr));
> return;
> }
> else
> {
> - //Deallocate the last block in the list of free lists, and
> - //insert the new one in it's correct position.
> - operator delete((void*)_S_free_list.back());
> + // Deallocate the last block in the list of free lists,
> + // and insert the new one in it's correct position.
> + operator delete(static_cast<void*>(_S_free_list.back()));
> _S_free_list.pop_back();
> }
> }
>
> - //Just add the block to the list of free lists
> - //unconditionally.
> - _FLIter __temp = std::lower_bound(_S_free_list.begin(), _S_free_list.end(),
> - *__addr, _LT_pointer_compare ());
> - //We may insert the new free list before _temp;
> + // Just add the block to the list of free lists unconditionally.
> + iterator __temp = __gnu_cxx::balloc::__lower_bound
> + (_S_free_list.begin(), _S_free_list.end(),
> + *__addr, _LT_pointer_compare());
> +
> + // We may insert the new free list before _temp;
> _S_free_list.insert(__temp, __addr);
> }
>
> - static bool _S_should_i_give(unsigned int __block_size, unsigned int __required_size) throw()
> + bool
> + _M_should_i_give(unsigned int __block_size,
> + unsigned int __required_size) throw()
> {
> const unsigned int __max_wastage_percentage = 36;
> if (__block_size >= __required_size &&
> - (((__block_size - __required_size) * 100 / __block_size) < __max_wastage_percentage))
> + (((__block_size - __required_size) * 100 / __block_size)
> + < __max_wastage_percentage))
> return true;
> else
> return false;
> }
>
> public:
> - typedef _BA_free_list_store _BFL_type;
> -
> - static inline void _S_insert_free_list(unsigned int *__addr) throw()
> + inline void
> + _M_insert(unsigned int* __addr) throw()
> {
> #if defined __GTHREADS
> - _Lock __bfl_lock(&_S_bfl_mutex);
> + _Auto_Lock __bfl_lock(&_S_bfl_mutex);
> #endif
> - //Call _S_validate_free_list to decide what should be done with this
> - //particular free list.
> - _S_validate_free_list(--__addr);
> + // Call _M_validate to decide what should be done with
> + // this particular free list.
> + this->_M_validate(reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>(__addr)
> + - sizeof(unsigned int)));
> }
>
> - static unsigned int *_S_get_free_list(unsigned int __sz) throw (std::bad_alloc)
> - {
> -#if defined __GTHREADS
> - _Lock __bfl_lock(&_S_bfl_mutex);
> -#endif
> - _FLIter __temp = std::lower_bound(_S_free_list.begin(), _S_free_list.end(),
> - __sz, _LT_pointer_compare());
> - if (__temp == _S_free_list.end() || !_S_should_i_give (**__temp, __sz))
> - {
> - //We hold the lock because the OOM_Handler is a stateless
> - //entity.
> - _OOM_handler __set_handler(_BFL_type::_S_clear);
> - unsigned int *__ret_val = reinterpret_cast<unsigned int*>
> - (operator new (__sz + sizeof(unsigned int)));
> - *__ret_val = __sz;
> - return ++__ret_val;
> - }
> - else
> - {
> - unsigned int* __ret_val = *__temp;
> - _S_free_list.erase (__temp);
> - return ++__ret_val;
> - }
> - }
> -
> - //This function just clears the internal Free List, and gives back
> - //all the memory to the OS.
> - static void _S_clear()
> - {
> -#if defined __GTHREADS
> - _Lock __bfl_lock(&_S_bfl_mutex);
> -#endif
> - _FLIter __iter = _S_free_list.begin();
> - while (__iter != _S_free_list.end())
> - {
> - operator delete((void*)*__iter);
> - ++__iter;
> - }
> - _S_free_list.clear();
> - }
> + unsigned int*
> + _M_get(unsigned int __sz) throw(std::bad_alloc);
>
> + // This function just clears the internal Free List, and gives back
> + // all the memory to the OS.
> + void
> + _M_clear();
> };
>
> -#if defined __GTHREADS
> - _Mutex _BA_free_list_store::_S_bfl_mutex;
> -#endif
> - std::vector<unsigned int*> _BA_free_list_store::_S_free_list;
>
> - template <typename _Tp> class bitmap_allocator;
> - // specialize for void:
> - template <> class bitmap_allocator<void> {
> - public:
> - typedef void* pointer;
> - typedef const void* const_pointer;
> - // reference-to-void members are impossible.
> - typedef void value_type;
> - template <typename _Tp1> struct rebind { typedef bitmap_allocator<_Tp1> other; };
> - };
> + // Forward declare the class.
> + template<typename _Tp>
> + class bitmap_allocator;
> +
> + // Specialize for void:
> + template<>
> + class bitmap_allocator<void>
> + {
> + public:
> + typedef void* pointer;
> + typedef const void* const_pointer;
>
> - template <typename _Tp> class bitmap_allocator : private _BA_free_list_store {
> - 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 bitmap_allocator<_Tp1> other; };
> -
> - private:
> - static const unsigned int _Bits_Per_Byte = 8;
> - static const unsigned int _Bits_Per_Block = sizeof(unsigned int) * _Bits_Per_Byte;
> + // Reference-to-void members are impossible.
> + typedef void value_type;
> + template<typename _Tp1>
> + struct rebind
> + {
> + typedef bitmap_allocator<_Tp1> other;
> + };
> + };
>
> - static inline void _S_bit_allocate(unsigned int *__pbmap, unsigned int __pos) throw()
> - {
> - unsigned int __mask = 1 << __pos;
> - __mask = ~__mask;
> - *__pbmap &= __mask;
> - }
> -
> - static inline void _S_bit_free(unsigned int *__pbmap, unsigned int __pos) throw()
> + template<typename _Tp>
> + class bitmap_allocator : private free_list
> {
> - unsigned int __mask = 1 << __pos;
> - *__pbmap |= __mask;
> - }
> + public:
> + typedef std::size_t size_type;
> + typedef std::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 bitmap_allocator<_Tp1> other;
> + };
>
> - static inline void *_S_memory_get(size_t __sz) throw (std::bad_alloc)
> - {
> - return operator new(__sz);
> - }
> + private:
> + template<unsigned int _BSize, unsigned int _AlignSize>
> + struct aligned_size
> + {
> + enum
> + {
> + modulus = _BSize % _AlignSize,
> + value = _BSize + (modulus ? _AlignSize - (modulus) : 0)
> + };
> + };
>
> - static inline void _S_memory_put(void *__vptr) throw ()
> - {
> - operator delete(__vptr);
> - }
> + struct _Alloc_block
> + {
> + char __unused[aligned_size<sizeof(value_type), 8>::value];
> + };
>
> - typedef typename std::pair<pointer, pointer> _Block_pair;
> - typedef typename __gnu_cxx::new_allocator<_Block_pair> _BPVec_allocator_type;
> - typedef typename std::vector<_Block_pair, _BPVec_allocator_type> _BPVector;
>
> + typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair;
>
> -#if defined CHECK_FOR_ERRORS
> - //Complexity: O(lg(N)). Where, N is the number of block of size
> - //sizeof(value_type).
> - static void _S_check_for_free_blocks() throw()
> - {
> - typedef typename __gnu_cxx::__aux_balloc::_Ffit_finder<pointer, _BPVec_allocator_type> _FFF;
> - _FFF __fff;
> - typedef typename _BPVector::iterator _BPiter;
> - _BPiter __bpi = std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
> - __gnu_cxx::__aux_balloc::_Functor_Ref<_FFF>(__fff));
> - assert(__bpi == _S_mem_blocks.end());
> - }
> -#endif
> + typedef typename
> + balloc::__mini_vector<_Block_pair> _BPVector;
>
> +#if defined _BALLOC_SANITY_CHECK
> + // Complexity: O(lg(N)). Where, N is the number of block of size
> + // sizeof(value_type).
> + void
> + _S_check_for_free_blocks() throw()
> + {
> + typedef typename
> + __gnu_cxx::balloc::_Ffit_finder<_Alloc_block*> _FFF;
> + _FFF __fff;
> + typedef typename _BPVector::iterator _BPiter;
> + _BPiter __bpi =
> + __gnu_cxx::balloc::__find_if
> + (_S_mem_blocks.begin(), _S_mem_blocks.end(),
> + __gnu_cxx::balloc::_Functor_Ref<_FFF>(__fff));
>
> - //Complexity: O(1), but internally depends upon the complexity of
> - //the function _BA_free_list_store::_S_get_free_list. The part
> - //where the bitmap headers are written is of worst case complexity:
> - //O(X),where X is the number of blocks of size sizeof(value_type)
> - //within the newly acquired block. Having a tight bound.
> - static void _S_refill_pool() throw (std::bad_alloc)
> - {
> -#if defined CHECK_FOR_ERRORS
> - _S_check_for_free_blocks();
> + _BALLOC_ASSERT(__bpi == _S_mem_blocks.end());
> + }
> #endif
>
> - const unsigned int __num_bit_maps = _S_block_size / _Bits_Per_Block;
> - const unsigned int __size_to_allocate = sizeof(unsigned int) +
> - _S_block_size * sizeof(value_type) + __num_bit_maps*sizeof(unsigned int);
> -
> - unsigned int *__temp =
> - reinterpret_cast<unsigned int*>(_BA_free_list_store::_S_get_free_list(__size_to_allocate));
> - *__temp = 0;
> - ++__temp;
> + // Complexity: O(1), but internally depends upon the complexity
> + // of the function free_list::_M_get. The
> + // part where the bitmap headers are written is of worst case
> + // complexity: O(X),where X is the number of blocks of size
> + // sizeof(value_type) within the newly acquired block. Having a
> + // tight bound.
> + void
> + _S_refill_pool() throw(std::bad_alloc)
> + {
> +#if defined _BALLOC_SANITY_CHECK
> + _S_check_for_free_blocks();
> +#endif
>
> - //The Header information goes at the Beginning of the Block.
> - _Block_pair __bp = std::make_pair(reinterpret_cast<pointer>(__temp + __num_bit_maps),
> - reinterpret_cast<pointer>(__temp + __num_bit_maps)
> - + _S_block_size - 1);
> + const unsigned int __num_bitmaps = _S_block_size / balloc::bits_per_block;
> + const unsigned int __size_to_allocate = sizeof(unsigned int)
> + + _S_block_size * sizeof(_Alloc_block)
> + + __num_bitmaps * sizeof(unsigned int);
> +
> + unsigned int* __temp =
> + reinterpret_cast<unsigned int*>(this->_M_get(__size_to_allocate));
> + *__temp = 0;
> + // ++__temp;
> + __temp = reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>(__temp) + sizeof(unsigned int));
> +
> + // The Header information goes at the Beginning of the Block.
> + _Block_pair __bp =
> + std::make_pair(reinterpret_cast<_Alloc_block*>
> + (__temp + __num_bitmaps),
> + reinterpret_cast<_Alloc_block*>
> + (__temp + __num_bitmaps)
> + + _S_block_size - 1);
> +
> + // Fill the Vector with this information.
> + _S_mem_blocks.push_back(__bp);
>
> - //Fill the Vector with this information.
> - _S_mem_blocks.push_back(__bp);
> + unsigned int __bit_mask = 0; // 0 Indicates all Allocated.
> + __bit_mask = ~__bit_mask; // 1 Indicates all Free.
>
> - unsigned int __bit_mask = 0; //0 Indicates all Allocated.
> - __bit_mask = ~__bit_mask; //1 Indicates all Free.
> + for (unsigned int __i = 0; __i < __num_bitmaps; ++__i)
> + __temp[__i] = __bit_mask;
>
> - for (unsigned int __i = 0; __i < __num_bit_maps; ++__i)
> - __temp[__i] = __bit_mask;
> + _S_block_size *= 2;
> + }
>
> - //On some implementations, operator new might throw bad_alloc, or
> - //malloc might fail if the size passed is too large, therefore, we
> - //limit the size passed to malloc or operator new.
> - _S_block_size *= 2;
> - }
>
> - static _BPVector _S_mem_blocks;
> - static unsigned int _S_block_size;
> - static __gnu_cxx::__aux_balloc::_Bit_map_counter<pointer, _BPVec_allocator_type> _S_last_request;
> - static typename _BPVector::size_type _S_last_dealloc_index;
> + static _BPVector _S_mem_blocks;
> + static unsigned int _S_block_size;
> + static __gnu_cxx::balloc::
> + _Bitmap_counter<_Alloc_block*> _S_last_request;
> + static typename _BPVector::size_type _S_last_dealloc_index;
> #if defined __GTHREADS
> - static _Mutex _S_mut;
> + static _Mutex _S_mut;
> #endif
>
> - //Complexity: Worst case complexity is O(N), but that is hardly ever
> - //hit. if and when this particular case is encountered, the next few
> - //cases are guaranteed to have a worst case complexity of O(1)!
> - //That's why this function performs very well on the average. you
> - //can consider this function to be having a complexity refrred to
> - //commonly as: Amortized Constant time.
> - static pointer _S_allocate_single_object()
> - {
> + public:
> +
> + // Complexity: Worst case complexity is O(N), but that is hardly
> + // ever hit. if and when this particular case is encountered,
> + // the next few cases are guaranteed to have a worst case
> + // complexity of O(1)! That's why this function performs very
> + // well on the average. you can consider this function to be
> + // having a complexity referred to commonly as: Amortized
> + // Constant time.
> + pointer
> + _M_allocate_single_object() throw(std::bad_alloc)
> + {
> #if defined __GTHREADS
> - _Lock __bit_lock(&_S_mut);
> + _Auto_Lock __bit_lock(&_S_mut);
> #endif
>
> - //The algorithm is something like this: The last_requst variable
> - //points to the last accessed Bit Map. When such a condition
> - //occurs, we try to find a free block in the current bitmap, or
> - //succeeding bitmaps until the last bitmap is reached. If no free
> - //block turns up, we resort to First Fit method.
> + // The algorithm is something like this: The last_request
> + // variable points to the last accessed Bit Map. When such a
> + // condition occurs, we try to find a free block in the
> + // current bitmap, or succeeding bitmaps until the last bitmap
> + // is reached. If no free block turns up, we resort to First
> + // Fit method.
> +
> + // WARNING: Do not re-order the condition in the while
> + // statement below, because it relies on C++'s short-circuit
> + // evaluation. The return from _S_last_request->_M_get() will
> + // NOT be dereference able if _S_last_request->_M_finished()
> + // returns true. This would inevitably lead to a NULL pointer
> + // dereference if tinkered with.
> + while (_S_last_request._M_finished() == false
> + && (*(_S_last_request._M_get()) == 0))
> + {
> + _S_last_request.operator++();
> + }
>
> - //WARNING: Do not re-order the condition in the while statement
> - //below, because it relies on C++'s short-circuit
> - //evaluation. The return from _S_last_request->_M_get() will NOT
> - //be dereferenceable if _S_last_request->_M_finished() returns
> - //true. This would inevitibly lead to a NULL pointer dereference
> - //if tinkered with.
> - while (_S_last_request._M_finished() == false && (*(_S_last_request._M_get()) == 0))
> - {
> - _S_last_request.operator++();
> - }
> + if (__builtin_expect(_S_last_request._M_finished() == true, false))
> + {
> + // Fall Back to First Fit algorithm.
> + typedef typename
> + __gnu_cxx::balloc::_Ffit_finder<_Alloc_block*> _FFF;
> + _FFF __fff;
> + typedef typename _BPVector::iterator _BPiter;
> + _BPiter __bpi =
> + __gnu_cxx::balloc::__find_if
> + (_S_mem_blocks.begin(), _S_mem_blocks.end(),
> + __gnu_cxx::balloc::_Functor_Ref<_FFF>(__fff));
>
> - if (__builtin_expect(_S_last_request._M_finished() == true, false))
> - {
> - //Fall Back to First Fit algorithm.
> - typedef typename __gnu_cxx::__aux_balloc::_Ffit_finder<pointer, _BPVec_allocator_type> _FFF;
> - _FFF __fff;
> - typedef typename _BPVector::iterator _BPiter;
> - _BPiter __bpi = std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
> - __gnu_cxx::__aux_balloc::_Functor_Ref<_FFF>(__fff));
> + if (__bpi != _S_mem_blocks.end())
> + {
> + // Search was successful. Ok, now mark the first bit from
> + // the right as 0, meaning Allocated. This bit is obtained
> + // by calling _M_get() on __fff.
> + unsigned int __nz_bit = _Bit_scan_forward(*__fff._M_get());
> + balloc::__bit_allocate(__fff._M_get(), __nz_bit);
> +
> + _S_last_request._M_reset(__bpi - _S_mem_blocks.begin());
> +
> + // Now, get the address of the bit we marked as allocated.
> + pointer __ret = reinterpret_cast<pointer>
> + (__bpi->first + __fff._M_offset() + __nz_bit);
> + unsigned int* __puse_count = reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>
> + (__bpi->first) - (sizeof(unsigned int) *
> + (__gnu_cxx::balloc::__num_bitmaps(*__bpi)+1)));
> +
> + ++(*__puse_count);
> + return __ret;
> + }
> + else
> + {
> + // Search was unsuccessful. We Add more memory to the
> + // pool by calling _S_refill_pool().
> + _S_refill_pool();
> +
> + // _M_Reset the _S_last_request structure to the first
> + // free block's bit map.
> + _S_last_request._M_reset(_S_mem_blocks.size() - 1);
>
> - if (__bpi != _S_mem_blocks.end())
> - {
> - //Search was successful. Ok, now mark the first bit from
> - //the right as 0, meaning Allocated. This bit is obtained
> - //by calling _M_get() on __fff.
> - unsigned int __nz_bit = _Bit_scan_forward(*__fff._M_get());
> - _S_bit_allocate(__fff._M_get(), __nz_bit);
> -
> - _S_last_request._M_reset(__bpi - _S_mem_blocks.begin());
> -
> - //Now, get the address of the bit we marked as allocated.
> - pointer __ret_val = __bpi->first + __fff._M_offset() + __nz_bit;
> - unsigned int *__puse_count = reinterpret_cast<unsigned int*>(__bpi->first) -
> - (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(*__bpi) + 1);
> - ++(*__puse_count);
> - return __ret_val;
> - }
> - else
> - {
> - //Search was unsuccessful. We Add more memory to the pool
> - //by calling _S_refill_pool().
> - _S_refill_pool();
> -
> - //_M_Reset the _S_last_request structure to the first free
> - //block's bit map.
> - _S_last_request._M_reset(_S_mem_blocks.size() - 1);
> + // Now, mark that bit as allocated.
> + }
> + }
>
> - //Now, mark that bit as allocated.
> - }
> - }
> - //_S_last_request holds a pointer to a valid bit map, that points
> - //to a free block in memory.
> - unsigned int __nz_bit = _Bit_scan_forward(*_S_last_request._M_get());
> - _S_bit_allocate(_S_last_request._M_get(), __nz_bit);
> -
> - pointer __ret_val = _S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit;
> -
> - unsigned int *__puse_count = reinterpret_cast<unsigned int*>
> - (_S_mem_blocks[_S_last_request._M_where()].first) -
> - (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(_S_mem_blocks[_S_last_request._M_where()]) + 1);
> - ++(*__puse_count);
> - return __ret_val;
> - }
> -
> - //Complexity: O(lg(N)), but the worst case is hit quite often! I
> - //need to do something about this. I'll be able to work on it, only
> - //when I have some solid figures from a few real apps.
> - static void _S_deallocate_single_object(pointer __p) throw()
> - {
> + // _S_last_request holds a pointer to a valid bit map, that
> + // points to a free block in memory.
> + unsigned int __nz_bit = _Bit_scan_forward(*_S_last_request._M_get());
> + balloc::__bit_allocate(_S_last_request._M_get(), __nz_bit);
> +
> + pointer __ret = reinterpret_cast<pointer>
> + (_S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit);
> +
> + unsigned int* __puse_count = reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>
> + (_S_mem_blocks[_S_last_request._M_where()].first)
> + - (sizeof(unsigned int) *
> + (__gnu_cxx::balloc::
> + __num_bitmaps(_S_mem_blocks[_S_last_request._M_where()])+1)));
> +
> + ++(*__puse_count);
> + return __ret;
> + }
> +
> + // Complexity: O(lg(N)), but the worst case is hit quite often!
> + // I need to do something about this. I'll be able to work on
> + // it, only when I have some solid figures from a few real apps.
> + void
> + _M_deallocate_single_object(pointer __p) throw()
> + {
> #if defined __GTHREADS
> - _Lock __bit_lock(&_S_mut);
> + _Auto_Lock __bit_lock(&_S_mut);
> #endif
> + _Alloc_block* __real_p = reinterpret_cast<_Alloc_block*>(__p);
>
> - typedef typename _BPVector::iterator _Iterator;
> - typedef typename _BPVector::difference_type _Difference_type;
> + typedef typename _BPVector::iterator _Iterator;
> + typedef typename _BPVector::difference_type _Difference_type;
>
> - _Difference_type __diff;
> - int __displacement;
> + _Difference_type __diff;
> + int __displacement;
>
> - assert(_S_last_dealloc_index >= 0);
> + _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
>
> - if (__gnu_cxx::__aux_balloc::_Inclusive_between<pointer>(__p)(_S_mem_blocks[_S_last_dealloc_index]))
> - {
> - assert(_S_last_dealloc_index <= _S_mem_blocks.size() - 1);
> +
> + if (__gnu_cxx::balloc::_Inclusive_between<_Alloc_block*>
> + (__real_p)
> + (_S_mem_blocks[_S_last_dealloc_index]))
> + {
> + _BALLOC_ASSERT(_S_last_dealloc_index <= _S_mem_blocks.size() - 1);
>
> - //Initial Assumption was correct!
> - __diff = _S_last_dealloc_index;
> - __displacement = __p - _S_mem_blocks[__diff].first;
> - }
> - else
> - {
> - _Iterator _iter = (std::find_if(_S_mem_blocks.begin(), _S_mem_blocks.end(),
> - __gnu_cxx::__aux_balloc::_Inclusive_between<pointer>(__p)));
> - assert(_iter != _S_mem_blocks.end());
> -
> - __diff = _iter - _S_mem_blocks.begin();
> - __displacement = __p - _S_mem_blocks[__diff].first;
> - _S_last_dealloc_index = __diff;
> - }
> + // Initial Assumption was correct!
> + __diff = _S_last_dealloc_index;
> + __displacement = __real_p - _S_mem_blocks[__diff].first;
> + }
> + else
> + {
> + _Iterator _iter =
> + __gnu_cxx::balloc::__find_if(_S_mem_blocks.begin(),
> + _S_mem_blocks.end(),
> + __gnu_cxx::balloc::
> + _Inclusive_between<_Alloc_block*>(__real_p));
> + _BALLOC_ASSERT(_iter != _S_mem_blocks.end());
> +
> + __diff = _iter - _S_mem_blocks.begin();
> + __displacement = __real_p - _S_mem_blocks[__diff].first;
> + _S_last_dealloc_index = __diff;
> + }
>
> - //Get the position of the iterator that has been found.
> - const unsigned int __rotate = __displacement % _Bits_Per_Block;
> - unsigned int *__bit_mapC = reinterpret_cast<unsigned int*>(_S_mem_blocks[__diff].first) - 1;
> - __bit_mapC -= (__displacement / _Bits_Per_Block);
> + // Get the position of the iterator that has been found.
> + const unsigned int __rotate = __displacement % balloc::bits_per_block;
> + unsigned int* __bitmapC =
> + reinterpret_cast<unsigned int*>(_S_mem_blocks[__diff].first) - 1;
> + __bitmapC -= (__displacement / balloc::bits_per_block);
>
> - _S_bit_free(__bit_mapC, __rotate);
> - unsigned int *__puse_count = reinterpret_cast<unsigned int*>
> - (_S_mem_blocks[__diff].first) -
> - (__gnu_cxx::__aux_balloc::__balloc_num_bit_maps(_S_mem_blocks[__diff]) + 1);
> -
> - assert(*__puse_count != 0);
> + balloc::__bit_free(__bitmapC, __rotate);
> + unsigned int* __puse_count = reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>
> + (_S_mem_blocks[__diff].first)
> + - (sizeof(unsigned int) *
> + (__gnu_cxx::balloc::__num_bitmaps(_S_mem_blocks[__diff])+1)));
> +
> + _BALLOC_ASSERT(*__puse_count != 0);
>
> - --(*__puse_count);
> + --(*__puse_count);
>
> - if (__builtin_expect(*__puse_count == 0, false))
> - {
> - _S_block_size /= 2;
> + if (__builtin_expect(*__puse_count == 0, false))
> + {
> + _S_block_size /= 2;
>
> - //We may safely remove this block.
> - _Block_pair __bp = _S_mem_blocks[__diff];
> - _S_insert_free_list(__puse_count);
> - _S_mem_blocks.erase(_S_mem_blocks.begin() + __diff);
> -
> - //We reset the _S_last_request variable to reflect the erased
> - //block. We do this to protect future requests after the last
> - //block has been removed from a particular memory Chunk,
> - //which in turn has been returned to the free list, and
> - //hence had been erased from the vector, so the size of the
> - //vector gets reduced by 1.
> - if ((_Difference_type)_S_last_request._M_where() >= __diff--)
> - {
> - _S_last_request._M_reset(__diff);
> - // assert(__diff >= 0);
> - }
> -
> - //If the Index into the vector of the region of memory that
> - //might hold the next address that will be passed to
> - //deallocated may have been invalidated due to the above
> - //erase procedure being called on the vector, hence we try
> - //to restore this invariant too.
> - if (_S_last_dealloc_index >= _S_mem_blocks.size())
> - {
> - _S_last_dealloc_index =(__diff != -1 ? __diff : 0);
> - assert(_S_last_dealloc_index >= 0);
> - }
> - }
> - }
> -
> - public:
> - bitmap_allocator() throw()
> - { }
> -
> - bitmap_allocator(const bitmap_allocator&) { }
> -
> - template <typename _Tp1> bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
> - { }
> -
> - ~bitmap_allocator() throw()
> - { }
> -
> - //Complexity: O(1), but internally the complexity depends upon the
> - //complexity of the function(s) _S_allocate_single_object and
> - //_S_memory_get.
> - pointer allocate(size_type __n)
> - {
> - if (__builtin_expect(__n == 1, true))
> - return _S_allocate_single_object();
> - else
> - return reinterpret_cast<pointer>(_S_memory_get(__n * sizeof(value_type)));
> - }
> -
> - //Complexity: Worst case complexity is O(N) where N is the number of
> - //blocks of size sizeof(value_type) within the free lists that the
> - //allocator holds. However, this worst case is hit only when the
> - //user supplies a bogus argument to hint. If the hint argument is
> - //sensible, then the complexity drops to O(lg(N)), and in extreme
> - //cases, even drops to as low as O(1). So, if the user supplied
> - //argument is good, then this function performs very well.
> - pointer allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
> - {
> - return allocate(__n);
> - }
> + // We can safely remove this block.
> + // _Block_pair __bp = _S_mem_blocks[__diff];
> + this->_M_insert(__puse_count);
> + _S_mem_blocks.erase(_S_mem_blocks.begin() + __diff);
> +
> + // Reset the _S_last_request variable to reflect the
> + // erased block. We do this to protect future requests
> + // after the last block has been removed from a particular
> + // memory Chunk, which in turn has been returned to the
> + // free list, and hence had been erased from the vector,
> + // so the size of the vector gets reduced by 1.
> + if ((_Difference_type)_S_last_request._M_where() >= __diff--)
> + _S_last_request._M_reset(__diff);
> +
> + // If the Index into the vector of the region of memory
> + // that might hold the next address that will be passed to
> + // deallocated may have been invalidated due to the above
> + // erase procedure being called on the vector, hence we
> + // try to restore this invariant too.
> + if (_S_last_dealloc_index >= _S_mem_blocks.size())
> + {
> + _S_last_dealloc_index =(__diff != -1 ? __diff : 0);
> + _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
> + }
> + }
> + }
>
> - void deallocate(pointer __p, size_type __n) throw()
> - {
> - if (__builtin_expect(__n == 1, true))
> - _S_deallocate_single_object(__p);
> - else
> - _S_memory_put(__p);
> - }
> + public:
> + bitmap_allocator() throw()
> + { }
>
> - pointer address(reference r) const { return &r; }
> - const_pointer address(const_reference r) const { return &r; }
> + bitmap_allocator(const bitmap_allocator&)
> + { }
>
> - size_type max_size(void) const throw() { return (size_type()-1)/sizeof(value_type); }
> + template<typename _Tp1>
> + bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
> + { }
>
> - void construct (pointer p, const_reference __data)
> - {
> - ::new(p) value_type(__data);
> - }
> + ~bitmap_allocator() throw()
> + { }
>
> - void destroy (pointer p)
> - {
> - p->~value_type();
> - }
> + // Complexity: O(1), but internally the complexity depends upon the
> + // complexity of the function(s) _S_allocate_single_object and
> + // operator new.
> + pointer
> + allocate(size_type __n)
> + {
> + if (__builtin_expect(__n == 1, true))
> + return this->_M_allocate_single_object();
> + else
> + {
> + const size_type __b = __n * sizeof(value_type);
> + return reinterpret_cast<pointer>(::operator new(__b));
> + }
> + }
>
> - };
> + pointer
> + allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
> + { return allocate(__n); }
>
> - template <typename _Tp>
> - typename bitmap_allocator<_Tp>::_BPVector bitmap_allocator<_Tp>::_S_mem_blocks;
> + void
> + deallocate(pointer __p, size_type __n) throw()
> + {
> + if (__builtin_expect(__n == 1, true))
> + this->_M_deallocate_single_object(__p);
> + else
> + ::operator delete(__p);
> + }
>
> - template <typename _Tp>
> - unsigned int bitmap_allocator<_Tp>::_S_block_size = bitmap_allocator<_Tp>::_Bits_Per_Block;
> + pointer
> + address(reference __r) const
> + { return &__r; }
> +
> + const_pointer
> + address(const_reference __r) const
> + { return &__r; }
> +
> + size_type
> + max_size() const throw()
> + { return (size_type()-1)/sizeof(value_type); }
> +
> + void
> + construct(pointer __p, const_reference __data)
> + { ::new(__p) value_type(__data); }
> +
> + void
> + destroy(pointer __p)
> + { __p->~value_type(); }
> + };
>
> - template <typename _Tp>
> - typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type
> - bitmap_allocator<_Tp>::_S_last_dealloc_index = 0;
> -
> - template <typename _Tp>
> - __gnu_cxx::__aux_balloc::_Bit_map_counter
> - <typename bitmap_allocator<_Tp>::pointer, typename bitmap_allocator<_Tp>::_BPVec_allocator_type>
> - bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks);
> + template<typename _Tp1, typename _Tp2>
> + bool
> + operator==(const bitmap_allocator<_Tp1>&,
> + const bitmap_allocator<_Tp2>&) throw()
> + { return true; }
> +
> + template<typename _Tp1, typename _Tp2>
> + bool
> + operator!=(const bitmap_allocator<_Tp1>&,
> + const bitmap_allocator<_Tp2>&) throw()
> + { return false; }
> +
> + // Static member definitions.
> + template<typename _Tp>
> + typename bitmap_allocator<_Tp>::_BPVector
> + bitmap_allocator<_Tp>::_S_mem_blocks;
> +
> + template<typename _Tp>
> + unsigned int bitmap_allocator<_Tp>::_S_block_size = balloc::bits_per_block;
> +
> + template<typename _Tp>
> + typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type
> + bitmap_allocator<_Tp>::_S_last_dealloc_index = 0;
> +
> + template<typename _Tp>
> + __gnu_cxx::balloc::_Bitmap_counter
> + <typename bitmap_allocator<_Tp>::_Alloc_block*>
> + bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks);
>
> #if defined __GTHREADS
> - template <typename _Tp>
> - __gnu_cxx::_Mutex
> - bitmap_allocator<_Tp>::_S_mut;
> + template<typename _Tp>
> + __gnu_cxx::_Mutex
> + bitmap_allocator<_Tp>::_S_mut;
> #endif
>
> - template <typename _Tp1, typename _Tp2>
> - bool operator== (const bitmap_allocator<_Tp1>&, const bitmap_allocator<_Tp2>&) throw()
> - {
> - return true;
> - }
> -
> - template <typename _Tp1, typename _Tp2>
> - bool operator!= (const bitmap_allocator<_Tp1>&, const bitmap_allocator<_Tp2>&) throw()
> - {
> - return false;
> - }
> +
> }
>
> +#endif
>
> -#endif //_BITMAP_ALLOCATOR_H
> +// LocalWords: namespace GTHREADS bool const gthread endif Mutex mutex
> diff -urN libstdc++-v3-orig/src/Makefile.am libstdc++-v3/src/Makefile.am
> --- libstdc++-v3-orig/src/Makefile.am 2004-09-02 00:16:56.000000000 +0200
> +++ libstdc++-v3/src/Makefile.am 2004-10-14 11:16:37.000000000 +0200
> @@ -96,6 +96,7 @@
>
> # Sources present in the src directory.
> sources = \
> + bitmap_allocator.cc \
> pool_allocator.cc \
> mt_allocator.cc \
> codecvt.cc \
> diff -urN libstdc++-v3-orig/src/bitmap_allocator.cc libstdc++-v3/src/bitmap_allocator.cc
> --- libstdc++-v3-orig/src/bitmap_allocator.cc 1970-01-01 01:00:00.000000000 +0100
> +++ libstdc++-v3/src/bitmap_allocator.cc 2004-10-14 11:16:37.000000000 +0200
> @@ -0,0 +1,133 @@
> +// Bitmap Allocator. Out of line function definitions. -*- C++ -*-
> +
> +// Copyright (C) 2004 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 2, 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.
> +
> +// You should have received a copy of the GNU General Public License along
> +// with this library; see the file COPYING. If not, write to the Free
> +// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
> +// USA.
> +
> +// As a special exception, you may use this file as part of a free software
> +// library without restriction. Specifically, if other files instantiate
> +// templates or use macros or inline functions from this file, or you compile
> +// this file and link it with other files to produce an executable, this
> +// file does not by itself cause the resulting executable to be covered by
> +// the GNU General Public License. This exception does not however
> +// invalidate any other reasons why the executable file might be covered by
> +// the GNU General Public License.
> +
> +#include <ext/bitmap_allocator.h>
> +
> +namespace __gnu_cxx
> +{
> + namespace balloc
> + {
> + template class __mini_vector<std::pair
> + <bitmap_allocator<char>::_Alloc_block*,
> + bitmap_allocator<char>::_Alloc_block*> >;
> +
> + template class __mini_vector<std::pair
> + <bitmap_allocator<wchar_t>::_Alloc_block*,
> + bitmap_allocator<wchar_t>::_Alloc_block*> >;
> +
> + template class __mini_vector<unsigned int*>;
> +
> + template unsigned int** __lower_bound
> + (unsigned int**, unsigned int**,
> + unsigned int const&, free_list::_LT_pointer_compare);
> + }
> +
> +#if defined __GTHREADS
> + _Mutex free_list::_S_bfl_mutex;
> +#endif
> + free_list::vector_type free_list::_S_free_list;
> +
> + unsigned int*
> + free_list::
> + _M_get(unsigned int __sz) throw(std::bad_alloc)
> + {
> +#if defined __GTHREADS
> + _Lock __bfl_lock(&_S_bfl_mutex);
> + __bfl_lock._M_lock();
> +#endif
> + iterator __temp =
> + __gnu_cxx::balloc::__lower_bound
> + (_S_free_list.begin(), _S_free_list.end(),
> + __sz, _LT_pointer_compare());
> +
> + if (__temp == _S_free_list.end() || !_M_should_i_give(**__temp, __sz))
> + {
> + // We release the lock here, because operator new is
> + // guaranteed to be thread-safe by the underlying
> + // implementation.
> +#if defined __GTHREADS
> + __bfl_lock._M_unlock();
> +#endif
> + // Try twice to get the memory: once directly, and the 2nd
> + // time after clearing the free list. If both fail, then
> + // throw std::bad_alloc().
> + unsigned int __ctr = 2;
> + while (__ctr)
> + {
> + unsigned int* __ret = 0;
> + --__ctr;
> + try
> + {
> + __ret = reinterpret_cast<unsigned int*>
> + (::operator new(__sz + sizeof(unsigned int)));
> + }
> + catch(...)
> + {
> + this->_M_clear();
> + }
> + if (!__ret)
> + continue;
> + *__ret = __sz;
> + return reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>(__ret) + sizeof(unsigned int));
> + }
> + throw std::bad_alloc();
> + }
> + else
> + {
> + unsigned int* __ret = *__temp;
> + _S_free_list.erase(__temp);
> +#if defined __GTHREADS
> + __bfl_lock._M_unlock();
> +#endif
> + return reinterpret_cast<unsigned int*>
> + (reinterpret_cast<char*>(__ret) + sizeof(unsigned int));
> + }
> + }
> +
> + void
> + free_list::
> + _M_clear()
> + {
> +#if defined __GTHREADS
> + _Auto_Lock __bfl_lock(&_S_bfl_mutex);
> +#endif
> + iterator __iter = _S_free_list.begin();
> + while (__iter != _S_free_list.end())
> + {
> + operator delete((void*)*__iter);
> + ++__iter;
> + }
> + _S_free_list.clear();
> + }
> +
> + // Instantiations.
> + template class bitmap_allocator<char>;
> + template class bitmap_allocator<wchar_t>;
> +} // namespace __gnu_cxx
--
-Dhruv Matani.
http://www.geocities.com/dhruvbird/
The price of freedom is responsibility, but it's a bargain, because
freedom is priceless. ~ Hugh Downs