// Bitmap Allocator. -*- C++ -*-
-// Copyright (C) 2004 Free Software Foundation, Inc.
+// Copyright (C) 2004-2014 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)
+// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// 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.
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
-// 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.
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
/** @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.
*/
#ifndef _BITMAP_ALLOCATOR_H
#define _BITMAP_ALLOCATOR_H 1
-// For std::size_t, and ptrdiff_t.
-#include <cstddef>
-
-// For std::pair.
-#include <utility>
-
-// For greater_equal, and less_equal.
-#include <functional>
-
-// For operator new.
-#include <new>
-
-// For __gthread_mutex_t, __gthread_mutex_lock and __gthread_mutex_unlock.
-#include <bits/gthr.h>
-
-// 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 _BALLOC_ASSERT(_EXPR) assert(_EXPR)
-#else
-#define _BALLOC_ASSERT(_EXPR)
-#endif
+#include <utility> // For std::pair.
+#include <bits/functexcept.h> // For __throw_bad_alloc().
+#include <functional> // For greater_equal, and less_equal.
+#include <new> // For operator new.
+#include <debug/debug.h> // _GLIBCXX_DEBUG_ASSERT
+#include <ext/concurrence.h>
+#include <bits/move.h>
+/** @brief The constant in the expression below is the alignment
+ * required in bytes.
+ */
+#define _BALLOC_ALIGN_BYTES 8
-namespace __gnu_cxx
+namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
-#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
-
-#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)
- {
-#if !defined __GTHREAD_MUTEX_INIT
- __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mut);
-#else
- __gthread_mutex_t __mtemp = __GTHREAD_MUTEX_INIT;
- _M_mut = __mtemp;
-#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)
- {
- _M_locked = true;
- __gthread_mutex_lock(_M_pmt->_M_get());
- }
- }
-
- void
- _M_unlock()
- {
- if (__threads_enabled)
- {
- if (__builtin_expect(_M_locked, true))
- {
- __gthread_mutex_unlock(_M_pmt->_M_get());
- _M_locked = false;
- }
- }
- }
-
- ~_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(); }
+ using std::size_t;
+ using std::ptrdiff_t;
- ~_Auto_Lock() { this->_M_unlock(); }
- };
-#endif
-
- namespace balloc
+ namespace __detail
{
- // __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.
+ _GLIBCXX_BEGIN_NAMESPACE_VERSION
+ /** @class __mini_vector bitmap_allocator.h bitmap_allocator.h
+ *
+ * @brief __mini_vector<> is a stripped down version of the
+ * full-fledged std::vector<>.
+ *
+ * It is to be used only for built-in types or PODs. Notable
+ * 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.
+ * Caveat: The dtor does NOT free the memory allocated, so this a
+ * memory-leaking vector!
+ */
template<typename _Tp>
class __mini_vector
{
typedef _Tp* pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
- typedef std::size_t size_type;
- typedef std::ptrdiff_t difference_type;
+ typedef size_t size_type;
+ typedef ptrdiff_t difference_type;
typedef pointer iterator;
private:
// 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);
- }
- }
+ __mini_vector()
+ : _M_start(0), _M_finish(0), _M_end_of_storage(0) { }
size_type
size() const throw()
struct __mv_iter_traits<_Tp*>
{
typedef _Tp value_type;
- typedef std::ptrdiff_t difference_type;
+ typedef ptrdiff_t difference_type;
};
enum
{
- bits_per_byte = 8,
- bits_per_block = sizeof(unsigned int) * bits_per_byte
+ bits_per_byte = 8,
+ bits_per_block = sizeof(size_t) * size_t(bits_per_byte)
};
template<typename _ForwardIterator, typename _Tp, typename _Compare>
__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;
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;
- }
-
+ /** @brief The number of Blocks pointed to by the address pair
+ * passed to the function.
+ */
template<typename _AddrPair>
inline size_t
__num_blocks(_AddrPair __ap)
{ return (__ap.second - __ap.first) + 1; }
+ /** @brief The number of Bit-maps pointed to by the address pair
+ * passed to the function.
+ */
template<typename _AddrPair>
- inline size_t
+ inline size_t
__num_bitmaps(_AddrPair __ap)
- { return __num_blocks(__ap) / bits_per_block; }
+ { return __num_blocks(__ap) / size_t(bits_per_block); }
// _Tp should be a pointer type.
template<typename _Tp>
{ return _M_fref(__arg); }
};
+ /** @class _Ffit_finder bitmap_allocator.h bitmap_allocator.h
+ *
+ * @brief The class which acts as a predicate for applying the
+ * first-fit memory allocation policy for the bitmap allocator.
+ */
// _Tp should be a pointer type, and _Alloc is the Allocator for
// the vector.
template<typename _Tp>
: 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 __detail::__mini_vector<_Block_pair> _BPVector;
typedef typename _BPVector::difference_type _Counter_type;
- unsigned int* _M_pbitmap;
- unsigned int _M_data_offset;
+ size_t* _M_pbitmap;
+ _Counter_type _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.
+ // Set the _rover to the last physical location bitmap,
+ // which is the bitmap which belongs to the first free
+ // block. Thus, the bitmaps are in exact reverse order of
+ // the actual memory layout. So, we count down the bitmaps,
+ // 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);
+ _Counter_type __diff = __detail::__num_bitmaps(__bp);
- if (*reinterpret_cast<unsigned int*>
- (reinterpret_cast<char*>(__bp.first) - (sizeof(unsigned int) *
- (__diff+1)))
- == __gnu_cxx::balloc::__num_blocks(__bp))
+ if (*(reinterpret_cast<size_t*>
+ (__bp.first) - (__diff + 1)) == __detail::__num_blocks(__bp))
return false;
- unsigned int* __rover = reinterpret_cast<unsigned int*>(__bp.first) - 1;
+ size_t* __rover = reinterpret_cast<size_t*>(__bp.first) - 1;
for (_Counter_type __i = 0; __i < __diff; ++__i)
{
}
return false;
}
-
- unsigned int*
+ size_t*
_M_get() const throw()
{ return _M_pbitmap; }
- unsigned int
+ _Counter_type
_M_offset() const throw()
- { return _M_data_offset * bits_per_block; }
+ { return _M_data_offset * size_t(bits_per_block); }
};
-
-
+ /** @class _Bitmap_counter bitmap_allocator.h bitmap_allocator.h
+ *
+ * @brief The bitmap counter which acts as the bitmap
+ * manipulator, and manages the bit-manipulation functions and
+ * the searching and identification functions on the bit-map.
+ */
// _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
+ __detail::__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;
+ size_t* _M_curr_bmap;
+ size_t* _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)
+ _Bitmap_counter(_BPVector& Rvbp, long __index = -1) : _M_vbp(Rvbp)
{ this->_M_reset(__index); }
void
- _M_reset(int __index = -1) throw()
+ _M_reset(long __index = -1) throw()
{
if (__index == -1)
{
}
_M_curr_index = __index;
- _M_curr_bmap = reinterpret_cast<unsigned int*>
+ _M_curr_bmap = reinterpret_cast<size_t*>
(_M_vbp[_M_curr_index].first) - 1;
-
- _BALLOC_ASSERT(__index <= (int)_M_vbp.size() - 1);
+
+ _GLIBCXX_DEBUG_ASSERT(__index <= (long)_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);
+ / size_t(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_set_internal_bitmap(size_t* __new_internal_marker) throw()
{ _M_curr_bmap = __new_internal_marker; }
bool
return *this;
}
- unsigned int*
+ size_t*
_M_get() const throw()
{ return _M_curr_bmap; }
_M_base() const throw()
{ return _M_vbp[_M_curr_index].first; }
- unsigned int
+ _Index_type
_M_offset() const throw()
{
- return bits_per_block
- * ((reinterpret_cast<unsigned int*>(this->_M_base())
+ return size_t(bits_per_block)
+ * ((reinterpret_cast<size_t*>(this->_M_base())
- _M_curr_bmap) - 1);
}
- unsigned int
+ _Index_type
_M_where() const throw()
{ return _M_curr_index; }
};
+ /** @brief Mark a memory address as allocated by re-setting the
+ * corresponding bit in the bit-map.
+ */
inline void
- __bit_allocate(unsigned int* __pbmap, unsigned int __pos) throw()
+ __bit_allocate(size_t* __pbmap, size_t __pos) throw()
{
- unsigned int __mask = 1 << __pos;
+ size_t __mask = 1 << __pos;
__mask = ~__mask;
*__pbmap &= __mask;
}
+ /** @brief Mark a memory address as free by setting the
+ * corresponding bit in the bit-map.
+ */
inline void
- __bit_free(unsigned int* __pbmap, unsigned int __pos) throw()
+ __bit_free(size_t* __pbmap, size_t __pos) throw()
{
- unsigned int __mask = 1 << __pos;
+ size_t __mask = 1 << __pos;
*__pbmap |= __mask;
}
- } // 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)); }
+ _GLIBCXX_END_NAMESPACE_VERSION
+ } // namespace __detail
+
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+ /** @brief Generic Version of the bsf instruction.
+ */
+ inline size_t
+ _Bit_scan_forward(size_t __num)
+ { return static_cast<size_t>(__builtin_ctzl(__num)); }
+
+ /** @class free_list bitmap_allocator.h bitmap_allocator.h
+ *
+ * @brief The free list class for managing chunks of memory to be
+ * given to and returned by the bitmap_allocator.
+ */
class free_list
{
- typedef unsigned int* value_type;
- typedef balloc::__mini_vector<value_type> vector_type;
- typedef vector_type::iterator iterator;
+ public:
+ typedef size_t* value_type;
+ typedef __detail::__mini_vector<value_type> vector_type;
+ typedef vector_type::iterator iterator;
+ typedef __mutex __mutex_type;
+ private:
struct _LT_pointer_compare
{
bool
- operator()(const unsigned int* __pui, const unsigned int __cui) const throw()
+ operator()(const size_t* __pui,
+ const size_t __cui) const throw()
{ return *__pui < __cui; }
};
-#if defined __GTHREADS
- static _Mutex _S_bfl_mutex;
+#if defined __GTHREADS
+ __mutex_type&
+ _M_get_mutex()
+ {
+ static __mutex_type _S_mutex;
+ return _S_mutex;
+ }
#endif
- static vector_type _S_free_list;
-
+
+ vector_type&
+ _M_get_free_list()
+ {
+ static vector_type _S_free_list;
+ return _S_free_list;
+ }
+
+ /** @brief Performs validation of memory based on their size.
+ *
+ * @param __addr The pointer to the memory block to be
+ * validated.
+ *
+ * Validates the memory block passed to this function and
+ * appropriately performs the action of managing the free list of
+ * blocks by adding this block to the free list or deleting this
+ * or larger blocks from the free list.
+ */
void
- _M_validate(unsigned int* __addr) throw()
+ _M_validate(size_t* __addr) throw()
{
- const unsigned int __max_size = 64;
- if (_S_free_list.size() >= __max_size)
+ vector_type& __free_list = _M_get_free_list();
+ const vector_type::size_type __max_size = 64;
+ if (__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())
+ if (*__addr >= *__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));
+ ::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();
+ // and insert the new one in its correct position.
+ ::operator delete(static_cast<void*>(__free_list.back()));
+ __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(),
+ iterator __temp = __detail::__lower_bound
+ (__free_list.begin(), __free_list.end(),
*__addr, _LT_pointer_compare());
// We may insert the new free list before _temp;
- _S_free_list.insert(__temp, __addr);
+ __free_list.insert(__temp, __addr);
}
+ /** @brief Decides whether the wastage of memory is acceptable for
+ * the current memory request and returns accordingly.
+ *
+ * @param __block_size The size of the block available in the free
+ * list.
+ *
+ * @param __required_size The required size of the memory block.
+ *
+ * @return true if the wastage incurred is acceptable, else returns
+ * false.
+ */
bool
- _M_should_i_give(unsigned int __block_size,
- unsigned int __required_size) throw()
+ _M_should_i_give(size_t __block_size,
+ size_t __required_size) throw()
{
- const unsigned int __max_wastage_percentage = 36;
+ const size_t __max_wastage_percentage = 36;
if (__block_size >= __required_size &&
(((__block_size - __required_size) * 100 / __block_size)
< __max_wastage_percentage))
}
public:
+ /** @brief This function returns the block of memory to the
+ * internal free list.
+ *
+ * @param __addr The pointer to the memory block that was given
+ * by a call to the _M_get function.
+ */
inline void
- _M_insert(unsigned int* __addr) throw()
+ _M_insert(size_t* __addr) throw()
{
#if defined __GTHREADS
- _Auto_Lock __bfl_lock(&_S_bfl_mutex);
+ __scoped_lock __bfl_lock(_M_get_mutex());
#endif
// 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)));
+ this->_M_validate(reinterpret_cast<size_t*>(__addr) - 1);
+ // See discussion as to why this is 1!
}
- 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.
+ /** @brief This function gets a block of memory of the specified
+ * size from the free list.
+ *
+ * @param __sz The size in bytes of the memory required.
+ *
+ * @return A pointer to the new memory block of size at least
+ * equal to that requested.
+ */
+ size_t*
+ _M_get(size_t __sz) throw(std::bad_alloc);
+
+ /** @brief This function just clears the internal Free List, and
+ * gives back all the memory to the OS.
+ */
void
_M_clear();
};
};
};
+ /**
+ * @brief Bitmap Allocator, primary template.
+ * @ingroup allocators
+ */
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;
+ 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;
+ typedef free_list::__mutex_type __mutex_type;
+
template<typename _Tp1>
struct rebind
{
typedef bitmap_allocator<_Tp1> other;
};
+#if __cplusplus >= 201103L
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2103. propagate_on_container_move_assignment
+ typedef std::true_type propagate_on_container_move_assignment;
+#endif
+
private:
- template<unsigned int _BSize, unsigned int _AlignSize>
+ template<size_t _BSize, size_t _AlignSize>
struct aligned_size
{
enum
struct _Alloc_block
{
- char __M_unused[aligned_size<sizeof(value_type), 8>::value];
+ char __M_unused[aligned_size<sizeof(value_type),
+ _BALLOC_ALIGN_BYTES>::value];
};
typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair;
- typedef typename
- balloc::__mini_vector<_Block_pair> _BPVector;
+ typedef typename __detail::__mini_vector<_Block_pair> _BPVector;
+ typedef typename _BPVector::iterator _BPiter;
+
+ template<typename _Predicate>
+ static _BPiter
+ _S_find(_Predicate __p)
+ {
+ _BPiter __first = _S_mem_blocks.begin();
+ while (__first != _S_mem_blocks.end() && !__p(*__first))
+ ++__first;
+ return __first;
+ }
-#if defined _BALLOC_SANITY_CHECK
+#if defined _GLIBCXX_DEBUG
// 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());
+ typedef typename __detail::_Ffit_finder<_Alloc_block*> _FFF;
+ _BPiter __bpi = _S_find(_FFF());
+
+ _GLIBCXX_DEBUG_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.
+ /** @brief Responsible for exponentially growing the internal
+ * memory pool.
+ *
+ * @throw std::bad_alloc. If memory can not be allocated.
+ *
+ * Complexity: O(1), but internally depends upon the
+ * complexity of the function free_list::_M_get. The part where
+ * the bitmap headers are written has 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
+#if defined _GLIBCXX_DEBUG
_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)
+ const size_t __num_bitmaps = (_S_block_size
+ / size_t(__detail::bits_per_block));
+ const size_t __size_to_allocate = sizeof(size_t)
+ _S_block_size * sizeof(_Alloc_block)
- + __num_bitmaps * sizeof(unsigned int);
+ + __num_bitmaps * sizeof(size_t);
- unsigned int* __temp =
- reinterpret_cast<unsigned int*>(this->_M_get(__size_to_allocate));
+ size_t* __temp =
+ reinterpret_cast<size_t*>(this->_M_get(__size_to_allocate));
*__temp = 0;
- // ++__temp;
- __temp = reinterpret_cast<unsigned int*>
- (reinterpret_cast<char*>(__temp) + sizeof(unsigned int));
+ ++__temp;
// The Header information goes at the Beginning of the Block.
_Block_pair __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.
-
- for (unsigned int __i = 0; __i < __num_bitmaps; ++__i)
- __temp[__i] = __bit_mask;
+ for (size_t __i = 0; __i < __num_bitmaps; ++__i)
+ __temp[__i] = ~static_cast<size_t>(0); // 1 Indicates all Free.
_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 size_t _S_block_size;
+ static __detail::_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_type _S_mut;
#endif
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.
+ /** @brief Allocates memory for a single object of size
+ * sizeof(_Tp).
+ *
+ * @throw std::bad_alloc. If memory can not be allocated.
+ *
+ * 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 average. You can consider this
+ * function to have 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);
+ __scoped_lock __bit_lock(_S_mut);
#endif
// The algorithm is something like this: The last_request
// dereference if tinkered with.
while (_S_last_request._M_finished() == false
&& (*(_S_last_request._M_get()) == 0))
- {
- _S_last_request.operator++();
- }
+ _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;
+ typedef typename __detail::_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));
+ _BPiter __bpi = _S_find(__detail::_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);
+ size_t __nz_bit = _Bit_scan_forward(*__fff._M_get());
+ __detail::__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)));
+ size_t* __puse_count =
+ reinterpret_cast<size_t*>
+ (__bpi->first) - (__detail::__num_bitmaps(*__bpi) + 1);
++(*__puse_count);
return __ret;
// _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);
+ size_t __nz_bit = _Bit_scan_forward(*_S_last_request._M_get());
+ __detail::__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)));
+ size_t* __puse_count = reinterpret_cast<size_t*>
+ (_S_mem_blocks[_S_last_request._M_where()].first)
+ - (__detail::
+ __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.
+ /** @brief Deallocates memory that belongs to a single object of
+ * size sizeof(_Tp).
+ *
+ * Complexity: O(lg(N)), but the worst case is not hit
+ * often! This is because containers usually deallocate memory
+ * close to each other and this case is handled in O(1) time by
+ * the deallocate function.
+ */
void
_M_deallocate_single_object(pointer __p) throw()
{
#if defined __GTHREADS
- _Auto_Lock __bit_lock(&_S_mut);
+ __scoped_lock __bit_lock(_S_mut);
#endif
_Alloc_block* __real_p = reinterpret_cast<_Alloc_block*>(__p);
typedef typename _BPVector::difference_type _Difference_type;
_Difference_type __diff;
- int __displacement;
+ long __displacement;
- _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
+ _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index >= 0);
-
- if (__gnu_cxx::balloc::_Inclusive_between<_Alloc_block*>
- (__real_p)
- (_S_mem_blocks[_S_last_dealloc_index]))
+ __detail::_Inclusive_between<_Alloc_block*> __ibt(__real_p);
+ if (__ibt(_S_mem_blocks[_S_last_dealloc_index]))
{
- _BALLOC_ASSERT(_S_last_dealloc_index <= _S_mem_blocks.size() - 1);
+ _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index
+ <= _S_mem_blocks.size() - 1);
// Initial Assumption was correct!
__diff = _S_last_dealloc_index;
}
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());
+ _Iterator _iter = _S_find(__ibt);
+
+ _GLIBCXX_DEBUG_ASSERT(_iter != _S_mem_blocks.end());
__diff = _iter - _S_mem_blocks.begin();
__displacement = __real_p - _S_mem_blocks[__diff].first;
}
// 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);
+ const size_t __rotate = (__displacement
+ % size_t(__detail::bits_per_block));
+ size_t* __bitmapC =
+ reinterpret_cast<size_t*>
+ (_S_mem_blocks[__diff].first) - 1;
+ __bitmapC -= (__displacement / size_t(__detail::bits_per_block));
- 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)));
+ __detail::__bit_free(__bitmapC, __rotate);
+ size_t* __puse_count = reinterpret_cast<size_t*>
+ (_S_mem_blocks[__diff].first)
+ - (__detail::__num_bitmaps(_S_mem_blocks[__diff]) + 1);
- _BALLOC_ASSERT(*__puse_count != 0);
+ _GLIBCXX_DEBUG_ASSERT(*__puse_count != 0);
--(*__puse_count);
if (_S_last_dealloc_index >= _S_mem_blocks.size())
{
_S_last_dealloc_index =(__diff != -1 ? __diff : 0);
- _BALLOC_ASSERT(_S_last_dealloc_index >= 0);
+ _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index >= 0);
}
}
}
public:
- bitmap_allocator() throw()
+ bitmap_allocator() _GLIBCXX_USE_NOEXCEPT
{ }
- bitmap_allocator(const bitmap_allocator&)
+ bitmap_allocator(const bitmap_allocator&) _GLIBCXX_USE_NOEXCEPT
{ }
template<typename _Tp1>
- bitmap_allocator(const bitmap_allocator<_Tp1>&) throw()
+ bitmap_allocator(const bitmap_allocator<_Tp1>&) _GLIBCXX_USE_NOEXCEPT
{ }
- ~bitmap_allocator() throw()
+ ~bitmap_allocator() _GLIBCXX_USE_NOEXCEPT
{ }
- // 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 (__n > this->max_size())
+ std::__throw_bad_alloc();
+
if (__builtin_expect(__n == 1, true))
return this->_M_allocate_single_object();
else
void
deallocate(pointer __p, size_type __n) throw()
{
- if (__builtin_expect(__n == 1, true))
- this->_M_deallocate_single_object(__p);
- else
- ::operator delete(__p);
+ if (__builtin_expect(__p != 0, true))
+ {
+ if (__builtin_expect(__n == 1, true))
+ this->_M_deallocate_single_object(__p);
+ else
+ ::operator delete(__p);
+ }
}
pointer
- address(reference __r) const
- { return &__r; }
+ address(reference __r) const _GLIBCXX_NOEXCEPT
+ { return std::__addressof(__r); }
const_pointer
- address(const_reference __r) const
- { return &__r; }
+ address(const_reference __r) const _GLIBCXX_NOEXCEPT
+ { return std::__addressof(__r); }
size_type
- max_size() const throw()
- { return (size_type()-1)/sizeof(value_type); }
-
+ max_size() const _GLIBCXX_USE_NOEXCEPT
+ { return size_type(-1) / sizeof(value_type); }
+
+#if __cplusplus >= 201103L
+ template<typename _Up, typename... _Args>
+ void
+ construct(_Up* __p, _Args&&... __args)
+ { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
+
+ template<typename _Up>
+ void
+ destroy(_Up* __p)
+ { __p->~_Up(); }
+#else
void
construct(pointer __p, const_reference __data)
- { ::new(__p) value_type(__data); }
+ { ::new((void *)__p) value_type(__data); }
void
destroy(pointer __p)
{ __p->~value_type(); }
+#endif
};
template<typename _Tp1, typename _Tp2>
bitmap_allocator<_Tp>::_S_mem_blocks;
template<typename _Tp>
- unsigned int bitmap_allocator<_Tp>::_S_block_size = balloc::bits_per_block;
+ size_t bitmap_allocator<_Tp>::_S_block_size =
+ 2 * size_t(__detail::bits_per_block);
template<typename _Tp>
- typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type
+ typename 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*>
+ __detail::_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
+ typename bitmap_allocator<_Tp>::__mutex_type
bitmap_allocator<_Tp>::_S_mut;
#endif
-
-}
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace __gnu_cxx
#endif
-// LocalWords: namespace GTHREADS bool const gthread endif Mutex mutex
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