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Hi,
I've gotten the bitmap_allocator to work fine when compiled as the
default using --enable-libstdcxx-allocator=bitmap. This patch implements
that. However, there is scope for some other parts of the allocator to
be split up into separate units(files), which are independent of each
other. I can do that only if that is required, because all allocators
upto now are self-sustaining files by themselves.
Tested x86-Linux.
--
-Dhruv Matani.
http://www.geocities.com/dhruvbird/
template<typename Signature>
class CustomSignature : public Signature
{ };
*** bitmap_allocator.h 2004-03-24 23:57:43.000000000 +0530
--- /home/dhruv/projects/new_libstdc++-v3/bitmap_allocator.h 2004-07-20 18:05:49.000000000 +0530
***************
*** 27,79 ****
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
!
!
! #if !defined _BITMAP_ALLOCATOR_H
#define _BITMAP_ALLOCATOR_H 1
#include <cstddef>
! //For std::size_t, and ptrdiff_t.
#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.
#include <functional>
! //For greater_equal, and less_equal.
#include <new>
! //For operator new.
#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.
#include <cassert>
! #define NDEBUG
- //#define CHECK_FOR_ERRORS
- //#define __CPU_HAS_BACKWARD_BRANCH_PREDICTION
namespace __gnu_cxx
{
! namespace {
#if defined __GTHREADS
bool const __threads_enabled = __gthread_active_p();
#endif
-
}
#if defined __GTHREADS
! class _Mutex {
__gthread_mutex_t _M_mut;
! //Prevent Copying and assignment.
! _Mutex (_Mutex const&);
! _Mutex& operator= (_Mutex const&);
public:
! _Mutex ()
{
if (__threads_enabled)
{
--- 27,109 ----
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
! #ifndef _BITMAP_ALLOCATOR_H
#define _BITMAP_ALLOCATOR_H 1
#include <cstddef>
! // For std::size_t, and ptrdiff_t.
#include <utility>
! // For std::pair.
! // #include <iterator>
!
! // #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.
#include <functional>
! // For greater_equal, and less_equal.
#include <new>
! // For operator new.
#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 _BALLOC_SANITY_CHECK
+
+ #if defined _BALLOC_SANITY_CHECK
#include <cassert>
! #define _BALLOC_ASSERT(_EXPR) assert(_EXPR)
! #else
! #define _BALLOC_ASSERT(_EXPR)
! #endif
!
!
! #define _BIT_ALLOCATE(_PBMAP,_POS) \
! { \
! unsigned int* __pbmap = _PBMAP; \
! unsigned int __mask = 1 << _POS; \
! __mask = ~__mask; \
! *_PBMAP &= __mask; \
! }
!
! #define _BIT_FREE(_PBMAP,_POS) \
! { \
! unsigned int* __pbmap = _PBMAP; \
! unsigned int __mask = 1 << _POS; \
! *__pbmap |= __mask; \
! }
!
! #define _MEMORY_GET(_SZ) (operator new(_SZ))
! #define _MEMORY_PUT(_VPTR) (operator delete(_VPTR))
namespace __gnu_cxx
{
! namespace
! {
#if defined __GTHREADS
+ // 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
}
#if defined __GTHREADS
! // _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&);
!
public:
! _Mutex()
{
if (__threads_enabled)
{
*************** namespace __gnu_cxx
*** 85,108 ****
#endif
}
}
! ~_Mutex ()
{
! //Gthreads does not define a Mutex Destruction Function.
}
! __gthread_mutex_t *_M_get() { return &_M_mut; }
};
! class _Lock {
_Mutex* _M_pmt;
bool _M_locked;
! //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()
{
if (__threads_enabled)
{
--- 115,152 ----
#endif
}
}
!
! ~_Mutex()
{
! // Gthreads does not define a Mutex Destruction Function.
}
!
! __gthread_mutex_t*
! _M_get() { return &_M_mut; }
};
! // _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&);
!
public:
_Lock(_Mutex* __mptr)
! : _M_pmt(__mptr), _M_locked(false)
! { }
!
! void
! _M_lock()
{
if (__threads_enabled)
{
*************** namespace __gnu_cxx
*** 110,116 ****
__gthread_mutex_lock(_M_pmt->_M_get());
}
}
! void _M_unlock()
{
if (__threads_enabled)
{
--- 154,162 ----
__gthread_mutex_lock(_M_pmt->_M_get());
}
}
!
! void
! _M_unlock()
{
if (__threads_enabled)
{
*************** namespace __gnu_cxx
*** 121,468 ****
}
}
}
! ~_Lock() { this->_M_unlock(); }
};
- #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;
!
! template <typename _Addr_Pair_t>
! inline size_t __balloc_num_blocks (_Addr_Pair_t __ap)
{
! return (__ap.second - __ap.first) + 1;
}
! template <typename _Addr_Pair_t>
! inline size_t __balloc_num_bit_maps (_Addr_Pair_t __ap)
{
! return __balloc_num_blocks(__ap) / _Bits_Per_Block;
}
! //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:
! _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); }
! };
! //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;
! 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::__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;
! 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;
}
!
! 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()
{
! if (__index == -1)
! {
! _M_curr_bmap = 0;
! _M_curr_index = (_Index_type)-1;
! return;
! }
! _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()
! {
! _M_curr_bmap = __new_internal_marker;
! }
! bool _M_finished () const throw()
! {
! return (_M_curr_bmap == 0);
! }
! _Bit_map_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 ()
! {
! return _M_curr_bmap;
! }
! pointer _M_base () { return _M_vbp[_M_curr_index].first; }
! unsigned int _M_offset ()
! {
! return _Bits_Per_Block * ((reinterpret_cast<unsigned int*>(this->_M_base()) - _M_curr_bmap) - 1);
! }
! unsigned int _M_where () { return _M_curr_index; }
! };
! }
! //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));
! }
!
! 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;
! _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;
! }
!
! static void _S_handle_oom_proc()
! {
! _S_oom_fcp();
! std::set_new_handler (_S_old_handler);
! _S_handled_oom = true;
! }
!
! ~_OOM_handler ()
! {
! if (!_S_handled_oom)
! std::set_new_handler (_S_old_handler);
! }
! };
!
! 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;
! class _BA_free_list_store {
! struct _LT_pointer_compare {
! template <typename _Tp>
! bool operator() (_Tp* __pt, _Tp const& __crt) const throw()
! {
! return *__pt < __crt;
! }
};
! #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()
{
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.
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);
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());
_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;
_S_free_list.insert(__temp, __addr);
}
! static bool _S_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))
return true;
else
return false;
}
public:
! typedef _BA_free_list_store _BFL_type;
!
! static inline void _S_insert_free_list(unsigned int *__addr) throw()
{
#if defined __GTHREADS
! _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);
}
! 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);
--- 167,805 ----
}
}
}
!
! ~_Lock() { }
};
+ // _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&);
! void
! _M_lock()
{
! if (__threads_enabled)
! __gthread_mutex_lock(_M_pmt->_M_get());
}
! void
! _M_unlock()
{
! if (__threads_enabled)
! __gthread_mutex_unlock(_M_pmt->_M_get());
}
! public:
! _Auto_Lock(_Mutex* __mptr) : _M_pmt(__mptr)
! { this->_M_lock(); }
! ~_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
{
! __mini_vector(const __mini_vector&);
! __mini_vector& operator=(const __mini_vector&);
! 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);
+ }
+ }
! 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]; }
! void
! insert(iterator __pos, const_reference __x)
! {
! if (this->_M_space_left())
! {
! size_type __to_move = this->_M_finish - __pos;
! iterator __dest = this->end();
! iterator __src = this->end() - 1;
!
! ++this->_M_finish;
! while (__to_move)
! {
! *__dest = *__src;
! --__dest; --__src; --__to_move;
! }
! *__pos = __x;
! }
! else
! {
! 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)
! {
! *__start = *__first;
! ++__start; ++__first;
! }
! *__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;
! }
! }
! void
! push_back(const_reference __x)
! {
! if (this->_M_space_left())
! {
! *this->end() = __x;
! ++this->_M_finish;
! }
! else
! this->insert(this->end(), __x);
! }
! void
! pop_back() throw()
! { --this->_M_finish; }
! void
! erase(iterator __pos) throw()
! {
! while (__pos + 1 != this->end())
! {
! *__pos = __pos[1];
! ++__pos;
! }
! --this->_M_finish;
! }
! void
! clear() throw()
! { this->_M_finish = this->_M_start; }
! };
!
! template<typename _Tp>
! struct __mv_iter_traits
! {
! typedef typename _Tp::value_type value_type;
! typedef typename _Tp::difference_type difference_type;
! };
!
! template<typename _Tp>
! struct __mv_iter_traits<_Tp*>
! {
! 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)
! {
! typedef typename __mv_iter_traits<_ForwardIterator>::value_type
! _ValueType;
! typedef typename __mv_iter_traits<_ForwardIterator>::difference_type
! _DistanceType;
! // typedef typename _ForwardIterator::value_type _ValueType;
! // typedef typename _ForwardIterator::difference_type _DistanceType;
!
! _DistanceType __len = std::distance(__first, __last);
! _DistanceType __half;
! _ForwardIterator __middle;
! while (__len > 0)
{
! __half = __len >> 1;
! __middle = __first;
! std::advance(__middle, __half);
! if (__comp(*__middle, __val))
{
! __first = __middle;
! ++__first;
! __len = __len - __half - 1;
}
! else
! __len = __half;
}
! return __first;
}
!
! template<typename _InputIterator, typename _Predicate>
! inline _InputIterator
! __find_if(_InputIterator __first, _InputIterator __last, _Predicate __p)
{
! 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);
+
+ _BALLOC_ASSERT(*(reinterpret_cast<unsigned int*>(__bp.first)
+ - (__diff + 1))
+ <= __gnu_cxx::balloc::__num_blocks(__bp));
+
+ if (*(reinterpret_cast<unsigned int*>(__bp.first) - (__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;
+ }
! 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
{
! typedef typename balloc::__mini_vector<typename std::pair<_Tp, _Tp> >
! _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.
! _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;
! }
! _M_curr_index = __index;
! _M_curr_bmap = reinterpret_cast<unsigned int*>
! (_M_vbp[_M_curr_index].first) - 1;
! _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);
! }
! // 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; }
! 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; }
! };
!
! // inline void
! // __bit_allocate(unsigned int* __pbmap, unsigned int __pos)// throw()
! // {
! // unsigned int __mask = 1 << __pos;
! // __mask = ~__mask;
! // *__pbmap &= __mask;
! // }
+ // inline void
+ // __bit_free(unsigned int* __pbmap, unsigned int __pos)// throw()
+ // {
+ // unsigned int __mask = 1 << __pos;
+ // *__pbmap |= __mask;
+ // }
+
+ // inline void*
+ // __memory_get(size_t __sz)// throw(std::bad_alloc)
+ // { return operator new(__sz); }
+
+ // inline void
+ // __memory_put(void *__vptr)// throw()
+ // { operator delete(__vptr); }
+ } // namespace balloc
+
+ // 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
! {
! template<typename _Tp>
! bool
! operator()(_Tp* __pt, _Tp const& __crt) const throw()
! { return *__pt < __crt; }
};
! #if defined __GTHREADS
static _Mutex _S_bfl_mutex;
#endif
! 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.
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(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(static_cast<void*>(_S_free_list.back()));
_S_free_list.pop_back();
}
}
! // 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);
}
! 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))
return true;
else
return false;
}
public:
! inline void
! _M_insert(unsigned int* __addr) throw()
{
#if defined __GTHREADS
! _Auto_Lock __bfl_lock(&_S_bfl_mutex);
#endif
! // Call _M_validate to decide what should be done with
! // this particular free list.
! this->_M_validate(--__addr);
}
! unsigned int*
! _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 ++__ret;
! }
! throw std::bad_alloc();
}
else
{
! unsigned int* __ret = *__temp;
! _S_free_list.erase(__temp);
! #if defined __GTHREADS
! __bfl_lock._M_unlock();
! #endif
! return ++__ret;
}
}
! // This function just clears the internal Free List, and gives back
! // all the memory to the OS.
! void
! _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);
*************** namespace __gnu_cxx
*** 470,859 ****
}
_S_free_list.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; };
! };
!
! 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;
!
! 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()
{
! unsigned int __mask = 1 << __pos;
! *__pbmap |= __mask;
! }
! static inline void *_S_memory_get(size_t __sz) throw (std::bad_alloc)
! {
! return operator new(__sz);
! }
! static inline void _S_memory_put(void *__vptr) throw ()
{
! operator delete(__vptr);
! }
! 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;
- #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
! //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();
! #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;
! //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);
! //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.
! for (unsigned int __i = 0; __i < __num_bit_maps; ++__i)
! __temp[__i] = __bit_mask;
! //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;
#if defined __GTHREADS
! 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()
! {
#if defined __GTHREADS
! _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.
!
! //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::__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());
! _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.
! }
! }
! //_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()
! {
#if defined __GTHREADS
! _Lock __bit_lock(&_S_mut);
#endif
! typedef typename _BPVector::iterator _Iterator;
! typedef typename _BPVector::difference_type _Difference_type;
! _Difference_type __diff;
! int __displacement;
! 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);
! //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;
! }
! //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);
! _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);
! --(*__puse_count);
! 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);
! }
! void deallocate(pointer __p, size_type __n) throw()
! {
! if (__builtin_expect(__n == 1, true))
! _S_deallocate_single_object(__p);
! else
! _S_memory_put(__p);
! }
! pointer address(reference r) const { return &r; }
! const_pointer address(const_reference r) const { return &r; }
! size_type max_size(void) 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 bitmap_allocator<_Tp>::_BPVector bitmap_allocator<_Tp>::_S_mem_blocks;
! template <typename _Tp>
! unsigned int bitmap_allocator<_Tp>::_S_block_size = bitmap_allocator<_Tp>::_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::__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);
#if defined __GTHREADS
! 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 //_BITMAP_ALLOCATOR_H
--- 807,1234 ----
}
_S_free_list.clear();
}
};
! // 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;
! // Reference-to-void members are impossible.
! typedef void value_type;
! template<typename _Tp1>
! struct rebind
! {
! typedef bitmap_allocator<_Tp1> other;
! };
! };
! template<typename _Tp>
! class bitmap_allocator : private free_list
{
! 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;
! };
! private:
! template<unsigned int _BSize, unsigned int _AlignSize>
! struct aligned_size
! {
! enum
! {
! modulus = _BSize % _AlignSize,
! value = _BSize + (modulus ? _AlignSize - (modulus) : 0)
! };
! };
+ struct _Alloc_block
+ {
+ char __unused[aligned_size<sizeof(value_type), 8>::value];
+ };
+ typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair;
! 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));
! _BALLOC_ASSERT(__bpi == _S_mem_blocks.end());
! }
! #endif
! // 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
! 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;
!
! // 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);
! 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;
! // 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::balloc::
! _Bitmap_counter<_Alloc_block*> _S_last_request;
! static typename _BPVector::size_type _S_last_dealloc_index;
#if defined __GTHREADS
! 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 referred to commonly as: Amortized
! // Constant time.
! pointer
! _M_allocate_single_object() throw(std::bad_alloc)
! {
#if defined __GTHREADS
! _Auto_Lock __bit_lock(&_S_mut);
#endif
! // 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++();
! }
! 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 (__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());
! _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*>(__bpi->first)
! - (__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);
! // 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());
! _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*>
! (_S_mem_blocks[_S_last_request._M_where()].first)
! - (__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
! _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;
! _Difference_type __diff;
! int __displacement;
! _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
!
! 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 = __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 % balloc::bits_per_block;
! unsigned int* __bitmapC =
! reinterpret_cast<unsigned int*>(_S_mem_blocks[__diff].first) - 1;
! __bitmapC -= (__displacement / balloc::bits_per_block);
! _BIT_FREE(__bitmapC, __rotate);
! unsigned int* __puse_count = reinterpret_cast<unsigned int*>
! (_S_mem_blocks[__diff].first)
! - (__gnu_cxx::balloc::__num_bitmaps(_S_mem_blocks[__diff]) + 1);
! _BALLOC_ASSERT(*__puse_count != 0);
! --(*__puse_count);
! if (__builtin_expect(*__puse_count == 0, false))
! {
! _S_block_size /= 2;
! // 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);
! }
! }
! }
! 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
! // __memory_get.
! 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>(_MEMORY_GET(__b));
! }
! }
! pointer
! allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
! { return allocate(__n); }
! void
! deallocate(pointer __p, size_type __n) throw()
! {
! if (__builtin_expect(__n == 1, true))
! this->_M_deallocate_single_object(__p);
! else
! _MEMORY_PUT(__p);
! }
! 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 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;
#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
! // LocalWords: namespace GTHREADS bool const gthread endif Mutex mutex
*** allocator.cc 2004-07-01 20:19:29.000000000 +0530
--- /home/dhruv/projects/new_libstdc++-v3/allocator.cc 2004-07-20 19:49:24.000000000 +0530
***************
*** 33,38 ****
--- 33,39 ----
#include <bits/c++config.h>
#include <memory>
+ #include <ext/bitmap_allocator.h>
#include <ext/mt_allocator.h>
#include <ext/pool_allocator.h>
*************** namespace __gnu_cxx
*** 166,169 ****
--- 167,183 ----
char* __pool_base::_S_end_free = 0;
size_t __pool_base::_S_heap_size = 0;
+
+ // Bitmap-allocator instantiations.
+ #if defined __GTHREADS
+ _Mutex free_list::_S_bfl_mutex;
+ #endif
+ free_list::vector_type free_list::_S_free_list;
+ namespace balloc
+ {
+ template unsigned int** __lower_bound
+ (unsigned int**, unsigned int**,
+ unsigned int const&, free_list::_LT_pointer_compare);
+ }
+
} // namespace __gnu_cxx
*** allocator-inst.cc 2004-06-25 11:40:44.000000000 +0530
--- /home/dhruv/projects/new_libstdc++-v3/allocator-inst.cc 2004-07-20 19:49:29.000000000 +0530
***************
*** 34,39 ****
--- 34,40 ----
#include <memory>
#include <ext/mt_allocator.h>
#include <ext/pool_allocator.h>
+ #include <ext/bitmap_allocator.h>
namespace std
{
*************** namespace __gnu_cxx
*** 48,51 ****
--- 49,55 ----
template class __pool_alloc<char>;
template class __pool_alloc<wchar_t>;
+
+ template class bitmap_allocator<char>;
+ template class bitmap_allocator<wchar_t>;
} // namespace __gnu_cxx
Attachment:
ChangeLog
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