__gnu_cxx::bitmap_allocator< _Tp >

Section: C Library Functions (3)
Updated: Wed Apr 17 2019
Page Index
 

NAME

__gnu_cxx::bitmap_allocator< _Tp > - Bitmap Allocator, primary template.

 

SYNOPSIS


Inherits __gnu_cxx::free_list.  

Public Types


typedef free_list::__mutex_type __mutex_type

typedef const _Tp * const_pointer

typedef const _Tp & const_reference

typedef ptrdiff_t difference_type

typedef _Tp * pointer

typedef std::true_type propagate_on_container_move_assignment

typedef _Tp & reference

typedef size_t size_type

typedef _Tp value_type
 

Public Member Functions


bitmap_allocator (const bitmap_allocator &) noexcept

template<typename _Tp1 > bitmap_allocator (const bitmap_allocator< _Tp1 > &) noexcept

pointer _M_allocate_single_object ()
Allocates memory for a single object of size sizeof(_Tp).
void _M_deallocate_single_object (pointer __p) throw ()
Deallocates memory that belongs to a single object of size sizeof(_Tp).
pointer address (reference __r) const noexcept

const_pointer address (const_reference __r) const noexcept

pointer allocate (size_type __n)

pointer allocate (size_type __n, typename bitmap_allocator< void >::const_pointer)

template<typename _Up , typename... _Args> void construct (_Up *__p, _Args &&... __args)

void deallocate (pointer __p, size_type __n) throw ()

template<typename _Up > void destroy (_Up *__p)

size_type max_size () const noexcept
 

Private Types


typedef vector_type::iterator iterator

typedef __detail::__mini_vector< value_type > vector_type
 

Private Member Functions


void _M_clear ()
This function just clears the internal Free List, and gives back all the memory to the OS.
size_t * _M_get (size_t __sz)
This function gets a block of memory of the specified size from the free list.
void _M_insert (size_t *__addr) throw ()
This function returns the block of memory to the internal free list.  

Detailed Description

 

template<typename _Tp>


class __gnu_cxx::bitmap_allocator< _Tp >" Bitmap Allocator, primary template.

Definition at line 660 of file bitmap_allocator.h.  

Member Function Documentation

 

template<typename _Tp > pointer __gnu_cxx::bitmap_allocator< _Tp >::_M_allocate_single_object () [inline]

Allocates memory for a single object of size sizeof(_Tp).

Exceptions:

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.

Definition at line 824 of file bitmap_allocator.h.

References __gnu_cxx::__detail::__bit_allocate(), __gnu_cxx::__detail::__num_bitmaps(), and __gnu_cxx::_Bit_scan_forward().  

template<typename _Tp > void __gnu_cxx::bitmap_allocator< _Tp >::_M_deallocate_single_object (pointer __p) [inline]

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.

Definition at line 914 of file bitmap_allocator.h.

 

Author

Generated automatically by Doxygen for libstdc++ from the source code.


 

Index

NAME
SYNOPSIS
Public Types
Public Member Functions
Private Types
Private Member Functions
Detailed Description
template<typename _Tp>
Member Function Documentation
template<typename _Tp > pointer __gnu_cxx::bitmap_allocator< _Tp >::_M_allocate_single_object () [inline]
template<typename _Tp > void __gnu_cxx::bitmap_allocator< _Tp >::_M_deallocate_single_object (pointer __p) [inline]
Author