Commit 1399eca1 by Dhruv Matani Committed by Paolo Carlini

bitmap_allocator.h: Clean-up add/remove functions.

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.

From-SVN: r89042
parent a023975e
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.
2004-10-13 Paolo Carlini <pcarlini@suse.de>
* include/bits/basic_string.tcc (_S_create): Use consistently
......
......@@ -270,7 +270,12 @@ GLIBCXX_3.4.3 {
_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;
......
// 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 @@ namespace __gnu_cxx
#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 @@ namespace __gnu_cxx
__gthread_mutex_lock(_M_pmt->_M_get());
}
}
void _M_unlock()
void
_M_unlock()
{
if (__threads_enabled)
{
......@@ -121,739 +151,1015 @@ namespace __gnu_cxx
}
}
}
~_Lock() { this->_M_unlock(); }
~_Lock() { }
};
#endif
// _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&);
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)
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&);
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);
}
}
_Functor_Ref (_Functor& __fref) : _M_fref(__fref) { }
result_type operator() (argument_type __arg) { return _M_fref (__arg); }
};
size_type
size() const throw()
{ return _M_finish - _M_start; }
iterator
begin() const throw()
{ return 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;
iterator
end() const throw()
{ return this->_M_finish; }
unsigned int *_M_pbitmap;
unsigned int _M_data_offset;
reference
back() const throw()
{ return *(this->end() - 1); }
public:
_Ffit_finder ()
: _M_pbitmap (0), _M_data_offset (0)
{ }
reference
operator[](const size_type __pos) const throw()
{ return this->_M_start[__pos]; }
void
insert(iterator __pos, const_reference __x);
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();
bool operator() (_Block_pair __bp) 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);
}
__len = __half;
}
else
{
--_M_curr_bmap;
}
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;
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()
// Specialize for void:
template<>
class bitmap_allocator<void>
{
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;
}
public:
typedef void* pointer;
typedef const void* const_pointer;
static inline void *_S_memory_get(size_t __sz) throw (std::bad_alloc)
{
return operator new(__sz);
}
// Reference-to-void members are impossible.
typedef void value_type;
template<typename _Tp1>
struct rebind
{
typedef bitmap_allocator<_Tp1> other;
};
};
static inline void _S_memory_put(void *__vptr) throw ()
template<typename _Tp>
class bitmap_allocator : private free_list
{
operator delete(__vptr);
}
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;
};
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;
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];
};
#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 std::pair<_Alloc_block*, _Alloc_block*> _Block_pair;
typedef typename
balloc::__mini_vector<_Block_pair> _BPVector;
//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();
#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
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.
//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++();
}
// 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::__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();
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());
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);
// _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;
}
// Now, mark that bit as allocated.
}
}
//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);
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);
_BALLOC_ASSERT(_S_last_dealloc_index >= 0);
//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());
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);
__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);
}
// 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);
}
}
}
//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()
{ }
public:
bitmap_allocator() throw()
{ }
bitmap_allocator(const bitmap_allocator&)
{ }
bitmap_allocator(const bitmap_allocator&) { }
template<typename _Tp1>
bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
{ }
template <typename _Tp1> bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
{ }
~bitmap_allocator() throw()
{ }
~bitmap_allocator() throw()
{ }
// 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));
}
}
//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)));
}
pointer
allocate(size_type __n, typename bitmap_allocator<void>::const_pointer)
{ return allocate(__n); }
//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))
this->_M_deallocate_single_object(__p);
else
::operator delete(__p);
}
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; }
pointer address(reference r) const { return &r; }
const_pointer address(const_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); }
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
construct(pointer __p, const_reference __data)
{ ::new(__p) value_type(__data); }
void destroy (pointer p)
{
p->~value_type();
}
void
destroy(pointer __p)
{ __p->~value_type(); }
};
};
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; }
template <typename _Tp>
typename bitmap_allocator<_Tp>::_BPVector bitmap_allocator<_Tp>::_S_mem_blocks;
// 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 = bitmap_allocator<_Tp>::_Bits_Per_Block;
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>
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 _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
......@@ -96,6 +96,7 @@ basic_file.cc: ${glibcxx_srcdir}/$(BASIC_FILE_CC)
# Sources present in the src directory.
sources = \
bitmap_allocator.cc \
pool_allocator.cc \
mt_allocator.cc \
codecvt.cc \
......
......@@ -64,14 +64,14 @@ am__objects_1 = atomicity.lo codecvt_members.lo collate_members.lo \
ctype_members.lo messages_members.lo monetary_members.lo \
numeric_members.lo time_members.lo
am__objects_2 = basic_file.lo c++locale.lo
am__objects_3 = pool_allocator.lo mt_allocator.lo codecvt.lo \
complex_io.lo ctype.lo debug.lo debug_list.lo functexcept.lo \
globals_locale.lo globals_io.lo ios.lo ios_failure.lo \
ios_init.lo ios_locale.lo limits.lo list.lo locale.lo \
locale_init.lo locale_facets.lo localename.lo stdexcept.lo \
strstream.lo tree.lo allocator-inst.lo concept-inst.lo \
fstream-inst.lo ext-inst.lo io-inst.lo istream-inst.lo \
locale-inst.lo locale-misc-inst.lo misc-inst.lo \
am__objects_3 = bitmap_allocator.lo pool_allocator.lo mt_allocator.lo \
codecvt.lo complex_io.lo ctype.lo debug.lo debug_list.lo \
functexcept.lo globals_locale.lo globals_io.lo ios.lo \
ios_failure.lo ios_init.lo ios_locale.lo limits.lo list.lo \
locale.lo locale_init.lo locale_facets.lo localename.lo \
stdexcept.lo strstream.lo tree.lo allocator-inst.lo \
concept-inst.lo fstream-inst.lo ext-inst.lo io-inst.lo \
istream-inst.lo locale-inst.lo locale-misc-inst.lo misc-inst.lo \
ostream-inst.lo sstream-inst.lo streambuf-inst.lo \
string-inst.lo valarray-inst.lo wlocale-inst.lo \
wstring-inst.lo $(am__objects_1) $(am__objects_2)
......@@ -306,6 +306,7 @@ host_sources_extra = \
# Sources present in the src directory.
sources = \
bitmap_allocator.cc \
pool_allocator.cc \
mt_allocator.cc \
codecvt.cc \
......
// 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
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