ut::allocator< T, Allocator_base > Class Template Reference

Allocator that allows std::* containers to manage their memory through ut::malloc* and ut::free library functions. More...

#include <ut0new.h>

Inheritance diagram for ut::allocator< T, Allocator_base >:

Classes
struct	rebind

Public Types
using	pointer = T *
using	const_pointer = const T *
using	reference = T &
using	const_reference = const T &
using	value_type = T
using	size_type = size_t
using	difference_type = ptrdiff_t

Public Member Functions
	allocator (PSI_memory_key key=mem_key_std)
	Default constructor. More...
	allocator (const allocator< T, Allocator_base > &)=default
allocator< T, Allocator_base > &	operator= (const allocator< T, Allocator_base > &)=default
	allocator (allocator< T, Allocator_base > &&)=default
allocator< T, Allocator_base > &	operator= (allocator< T, Allocator_base > &&)=default
	~allocator ()=default
template<typename U >
	allocator (const allocator< U, Allocator_base > &other)
	Copy-construct a new instance of allocator with type T by using existing instance of allocator constructed with a different type U. More...
bool	operator== (const ut::allocator< T, Allocator_base > &) const
	Equality of allocators instantiated with same types T. More...
bool	operator!= (const ut::allocator< T, Allocator_base > &other) const
	Non-equality of allocators instantiated with same types T. More...
size_type	max_size () const
	Return the maximum number of objects that can be allocated by this allocator. More...
pointer	allocate (size_type n_elements, const_pointer hint=nullptr)
	Allocates chunk of memory that can hold n_elements objects of type T. More...
void	deallocate (pointer ptr, size_type n_elements=0)
	Releases the memory allocated through ut::allocator<T>::allocate(). More...

Detailed Description

template<typename T, typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>
class ut::allocator< T, Allocator_base >

Allocator that allows std::* containers to manage their memory through ut::malloc* and ut::free library functions.

Main purpose of this custom allocator is to instrument all of the memory allocations and deallocations that are being done by std::* containers under the hood, and have them recorded through the PFS (memory) engine.

Other than std::* containers, this allocator is of course also suitable for use in any other allocator-aware containers and/or code.

Given that ut::malloc* and ut::free library functions already handle all the PFS and non-PFS implementation bits and pieces, this allocator is a mere wrapper around them.

Example which uses default PFS key (mem_key_std) to trace all std::vector allocations and deallocations: std::vector<int, ut::allocator<int>> vec; vec.push_back(...); ... vec.push_back(...);

Example which uses user-provided PFS key to trace std::vector allocations and deallocations: ut::allocator<int> allocator(some_other_psi_key); std::vector<int, ut::allocator<int>> vec(allocator); vec.push_back(...); ... vec.push_back(...);

Member Typedef Documentation

const_pointer

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::const_pointer = const T *

const_reference

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::const_reference = const T &

difference_type

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::difference_type = ptrdiff_t

pointer

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::pointer = T *

reference

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::reference = T &

size_type

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::size_type = size_t

value_type

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

using ut::allocator< T, Allocator_base >::value_type = T

Constructor & Destructor Documentation

allocator() [1/4]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

ut::allocator< T, Allocator_base >::allocator ( PSI_memory_key  key = mem_key_std )

inlineexplicit

Default constructor.

Parameters

[in]

key

performance schema key.

allocator() [2/4]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

ut::allocator< T, Allocator_base >::allocator ( const allocator< T, Allocator_base > &  )

default

allocator() [3/4]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

ut::allocator< T, Allocator_base >::allocator ( allocator< T, Allocator_base > &&  )

default

~allocator()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

ut::allocator< T, Allocator_base >::~allocator ( )

default

allocator() [4/4]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

template<typename U >

ut::allocator< T, Allocator_base >::allocator ( const allocator< U, Allocator_base > &  other )

inline

Copy-construct a new instance of allocator with type T by using existing instance of allocator constructed with a different type U.

Parameters

[in]

other

the allocator to copy from.

Member Function Documentation

allocate()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

pointer ut::allocator< T, Allocator_base >::allocate ( size_type  n_elements, const_pointer  hint = nullptr  )

inline

Allocates chunk of memory that can hold n_elements objects of type T.

Returned pointer is always valid. In case underlying allocation function was not able to fulfill the allocation request, this function will throw std::bad_alloc exception. After successful allocation, returned pointer must be passed back to ut::allocator<T>::deallocate() when no longer needed.

Parameters

[in]	n_elements	number of elements
[in]	hint	pointer to a nearby memory location, not used by this implementation

Returns

pointer to the allocated memory

deallocate()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

void ut::allocator< T, Allocator_base >::deallocate ( pointer  ptr, size_type  n_elements = 0  )

inline

Releases the memory allocated through ut::allocator<T>::allocate().

Parameters

[in,out]	ptr	pointer to memory to free
[in]	n_elements	number of elements allocated (unused)

max_size()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

size_type ut::allocator< T, Allocator_base >::max_size ( ) const

inline

Return the maximum number of objects that can be allocated by this allocator.

This number is somewhat lower for PFS-enabled builds because of extra few bytes needed for PFS.

operator!=()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

bool ut::allocator< T, Allocator_base >::operator!= ( const ut::allocator< T, Allocator_base > &  other ) const

inline

Non-equality of allocators instantiated with same types T.

operator=() [1/2]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

allocator< T, Allocator_base > & ut::allocator< T, Allocator_base >::operator= ( allocator< T, Allocator_base > &&  )

default

operator=() [2/2]

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

allocator< T, Allocator_base > & ut::allocator< T, Allocator_base >::operator= ( const allocator< T, Allocator_base > &  )

default

operator==()

template<typename T , typename Allocator_base = std::conditional_t< ut::WITH_PFS_MEMORY, detail::allocator_base_pfs<T>, detail::allocator_base<T>>>

bool ut::allocator< T, Allocator_base >::operator== ( const ut::allocator< T, Allocator_base > &  ) const

inline

Equality of allocators instantiated with same types T.

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The documentation for this class was generated from the following file:

• storage/innobase/include/ut0new.h