bslma::SequentialAllocator Class Reference

#include <bslma_sequentialallocator.h>

Inheritance diagram for bslma::SequentialAllocator:

Detailed Description

This class implements the ManagedAllocator protocol to provide a fast allocator of arbitrarily-sized blocks of memory. Both the release method and the destructor atomically delete all memory managed by this allocator; the deallocate method, however, has no effect for this class.

See bslma_sequentialallocator

Public Member Functions
	SequentialAllocator (Allocator *basicAllocator=0)
	SequentialAllocator (BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
	SequentialAllocator (int initialSize, Allocator *basicAllocator=0)
	SequentialAllocator (int initialSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
	SequentialAllocator (char *buffer, int bufferSize, Allocator *basicAllocator=0)
	SequentialAllocator (char *buffer, int bufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
	SequentialAllocator (int initialSize, int maxBufferSize, Allocator *basicAllocator=0)
	SequentialAllocator (int initialSize, int maxBufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
	SequentialAllocator (char *buffer, int bufferSize, int maxBufferSize, Allocator *basicAllocator=0)
	SequentialAllocator (char *buffer, int bufferSize, int maxBufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
	~SequentialAllocator () BSLS_KEYWORD_OVERRIDE
void *	allocate (size_type numBytes) BSLS_KEYWORD_OVERRIDE
void *	allocateAndExpand (int *size)
void *	allocateAndExpand (int *size, int maxNumBytes)
void	deallocate (void *address) BSLS_KEYWORD_OVERRIDE
int	expand (void *address, int originalNumBytes)
int	expand (void *address, int originalNumBytes, int maxNumBytes)
void	release () BSLS_KEYWORD_OVERRIDE
virtual void	reserveCapacity (int numBytes)
int	truncate (void *address, int originalNumBytes, int newNumBytes)
Public Member Functions inherited from bslma::Allocator
	~Allocator () BSLS_KEYWORD_OVERRIDE
template<class TYPE >
void	deleteObject (const TYPE *object)
template<class TYPE >
void	deleteObjectRaw (const TYPE *object)
void	deleteObject (bsl::nullptr_t)
void	deleteObjectRaw (bsl::nullptr_t)
Public Member Functions inherited from bsl::memory_resource
	memory_resource () BSLS_KEYWORD_DEFAULT
	memory_resource (const memory_resource &) BSLS_KEYWORD_DEFAULT
virtual	~memory_resource ()
memory_resource &	operator= (const memory_resource &) BSLS_KEYWORD_DEFAULT
BSLA_NODISCARD void *	allocate (size_t bytes, size_t alignment=k_MAX_ALIGN)
void	deallocate (void *p, size_t bytes, size_t alignment=k_MAX_ALIGN)
bool	is_equal (const memory_resource &other) const BSLS_KEYWORD_NOEXCEPT

Additional Inherited Members
Public Types inherited from bslma::Allocator
typedef std::size_t	size_type
Static Public Member Functions inherited from bslma::Allocator
static void	throwBadAlloc ()
Protected Member Functions inherited from bslma::Allocator
void *	do_allocate (std::size_t bytes, std::size_t alignment) BSLS_KEYWORD_OVERRIDE
void	do_deallocate (void *p, std::size_t bytes, std::size_t alignment) BSLS_KEYWORD_OVERRIDE
bool	do_is_equal (const memory_resource &other) const BSLS_KEYWORD_NOEXCEPT BSLS_KEYWORD_OVERRIDE

Constructor & Destructor Documentation

SequentialAllocator() [1/10]

bslma::SequentialAllocator::SequentialAllocator ( Allocator *  basicAllocator = 0 )

inlineexplicit

Create a sequential allocator for allocating memory blocks from an internal buffer. Optionally specify an alignment strategy used to align allocated memory blocks. If strategy is not specified, Natural Alignment is used. Optionally specify an initialSize the absolute value of which indicates the initial size (in bytes) for the internal buffer. If initialSize is not specified, an implementation-defined value is used. Optionally specify a basicAllocator used to supply memory. If basicAllocator is 0, the currently installed default allocator is used. If an allocate or reserveCapacity request cannot be satisfied from the current buffer, a new buffer is allocated, the size of which is determined by a buffer growth strategy implied by initialSize. If initialSize was specified and is negative, or if it was not specified, the buffer growth strategy used is Geometric Growth; otherwise it is Constant Growth. (See the component level documentation for further details.) In either case, the new buffer will have sufficient capacity to satisfy the request. If Geometric Growth is in effect, no limit is imposed on the size of buffers.

SequentialAllocator() [2/10]

bslma::SequentialAllocator::SequentialAllocator ( BufferAllocator::AlignmentStrategy  strategy, Allocator *  basicAllocator = 0  )

inlineexplicit

SequentialAllocator() [3/10]

bslma::SequentialAllocator::SequentialAllocator ( int  initialSize, Allocator *  basicAllocator = 0  )

inlineexplicit

SequentialAllocator() [4/10]

bslma::SequentialAllocator::SequentialAllocator ( int  initialSize, BufferAllocator::AlignmentStrategy  strategy, Allocator *  basicAllocator = 0  )

inline

SequentialAllocator() [5/10]

bslma::SequentialAllocator::SequentialAllocator ( char *  buffer, int  bufferSize, Allocator *  basicAllocator = 0  )

inline

Create a sequential allocator for allocating memory blocks initially from the specified buffer the size (in bytes) of which is indicated by the absolute value of the specified bufferSize. Optionally specify an alignment strategy used to align allocated memory blocks. If strategy is not specified, Natural Alignment is used. Optionally specify a basicAllocator used to supply memory. If basicAllocator is 0, the currently installed default allocator is used. If an allocate or reserveCapacity request cannot be satisfied from the current buffer, a new buffer is allocated, the size of which is determined by a buffer growth strategy implied by bufferSize. If bufferSize is negative, the buffer growth strategy used is Geometric Growth; otherwise it is Constant Growth. (See the component level documentation for further details.) In either case, the new buffer will have sufficient capacity to satisfy the request. If Geometric Growth is in effect, no limit is imposed on the size of buffers.

SequentialAllocator() [6/10]

bslma::SequentialAllocator::SequentialAllocator ( char *  buffer, int  bufferSize, BufferAllocator::AlignmentStrategy  strategy, Allocator *  basicAllocator = 0  )

inline

SequentialAllocator() [7/10]

bslma::SequentialAllocator::SequentialAllocator ( int  initialSize, int  maxBufferSize, Allocator *  basicAllocator = 0  )

inline

Create a sequential allocator for allocating memory blocks from an internal buffer the initial size (in bytes) of which is indicated by the absolute value of the specified initialSize. The specified maxBufferSize indicates the maximum size (in bytes) allowed for internally allocated buffers. Optionally specify an alignment strategy used to align allocated memory blocks. If strategy is not specified, Natural Alignment is used. Optionally specify a basicAllocator used to supply memory. If basicAllocator is 0, the currently installed default allocator is used. If an allocate or reserveCapacity request cannot be satisfied from the current buffer, a new buffer is allocated, the size of which is determined by a buffer growth strategy implied by initialSize. If initialSize is negative, the buffer growth strategy used is Geometric Growth; otherwise it is Constant Growth. (See the component level documentation for further details.) In either case, the new buffer will have sufficient capacity to satisfy the request. If Geometric Growth is in effect, the geometric progression of buffer sizes is capped at maxBufferSize.

Precondition

The behavior is undefined unless 0 < maxBufferSize, and |initialSize| <= maxBufferSize.

Note

Note that maxBufferSize is ignored if initialSize > 0. Also note that maxBufferSize may be overridden by a sufficiently large value passed to allocate or reserveCapacity.

SequentialAllocator() [8/10]

bslma::SequentialAllocator::SequentialAllocator ( int  initialSize, int  maxBufferSize, BufferAllocator::AlignmentStrategy  strategy, Allocator *  basicAllocator = 0  )

inline

SequentialAllocator() [9/10]

bslma::SequentialAllocator::SequentialAllocator ( char *  buffer, int  bufferSize, int  maxBufferSize, Allocator *  basicAllocator = 0  )

inline

Create a sequential allocator for allocating memory blocks initially from the specified buffer the size (in bytes) of which is indicated by the absolute value of the specified bufferSize. The specified maxBufferSize indicates the maximum size (in bytes) allowed for internally allocated buffers. Optionally specify an alignment strategy used to align allocated memory blocks. If strategy is not specified, Natural Alignment is used. Optionally specify a basicAllocator used to supply memory. If basicAllocator is 0, the currently installed default allocator is used. If an allocate or reserveCapacity request cannot be satisfied from the current buffer, a new buffer is allocated, the size of which is determined by a buffer growth strategy implied by bufferSize. If bufferSize is negative, the buffer growth strategy used is Geometric Growth; otherwise it is Constant Growth. (See the component level documentation for further details.) In either case, the new buffer will have sufficient capacity to satisfy the request. If Geometric Growth is in effect, the geometric progression of buffer sizes is capped at maxBufferSize.

Precondition

The behavior is undefined unless 0 < maxBufferSize, and |bufferSize| <= maxBufferSize.

Note

Note that maxBufferSize is ignored if bufferSize > 0. Also note that maxBufferSize may be overridden by a sufficiently large value passed to allocate or reserveCapacity.

SequentialAllocator() [10/10]

bslma::SequentialAllocator::SequentialAllocator ( char *  buffer, int  bufferSize, int  maxBufferSize, BufferAllocator::AlignmentStrategy  strategy, Allocator *  basicAllocator = 0  )

inline

~SequentialAllocator()

bslma::SequentialAllocator::~SequentialAllocator

(

)

Destroy this sequential allocator and release all associated memory.

Member Function Documentation

allocate()

void * bslma::SequentialAllocator::allocate ( size_type  numBytes )

inlinevirtual

Return a newly allocated block of memory of (at least) the specified positive size (bytes). If size is 0, a null pointer is returned with no effect.

Precondition

The behavior is undefined unless 0 <= size.

Note

Note that the alignment of the address returned is the maximum alignment for any fundamental type defined for the calling platform.

Implements bslma::Allocator.

allocateAndExpand() [1/2]

void * bslma::SequentialAllocator::allocateAndExpand ( int *  size )

inline

Return memory of at least the specified *size and return the actual amount of memory allocated in *size. If *size is 0, no memory is allocated and 0 is returned.

Precondition

The behavior is undefined unless 0 <= *size.

allocateAndExpand() [2/2]

void * bslma::SequentialAllocator::allocateAndExpand ( int *  size, int  maxNumBytes  )

inline

Return memory of at least the specified *size and at most the specified maxNumBytes. Also return the actual amount of memory allocated in *size. If *size is 0, no memory is allocated and 0 is returned.

Precondition

The behavior is undefined unless 0 <= *size <= maxNumBytes.

deallocate()

void bslma::SequentialAllocator::deallocate ( void *  address )

inlinevirtual

This method has no effect for this allocator.

Implements bslma::Allocator.

expand() [1/2]

int bslma::SequentialAllocator::expand ( void *  address, int  originalNumBytes  )

inline

Increase the amount of memory allocated at the specified address from the specified originalNumBytes to the maximum amount easily obtainable. Return the amount of memory available at address after the expansion.

Precondition

The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes.

Note

Note that this function will not expand the memory unless there have been no allocations since the allocation for originalNumBytes.

expand() [2/2]

int bslma::SequentialAllocator::expand ( void *  address, int  originalNumBytes, int  maxNumBytes  )

inline

Increase the amount of memory allocated at the specified address from the specified originalNumBytes to the maximum amount easily obtainable up to the specified maxNumBytes. Return the amount of memory available at address after the expansion.

Precondition

The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes and originalNumBytes < maxNumBytes.

Note

Note that this function will not expand the memory unless there have been no allocations since the allocation for originalNumBytes.

release()

void bslma::SequentialAllocator::release ( )

inlinevirtual

Release all memory currently allocated through this allocator.

Implements bslma::ManagedAllocator.

reserveCapacity()

void bslma::SequentialAllocator::reserveCapacity ( int  numBytes )

inlinevirtual

Reserve sufficient memory to satisfy allocation requests for at least the specified numBytes without replenishment (i.e., without internal allocation).

Precondition

The behavior is undefined unless 0 <= numBytes.

truncate()

int bslma::SequentialAllocator::truncate ( void *  address, int  originalNumBytes, int  newNumBytes  )

inline

Reduce the amount of memory allocated at the specified address from the specified originalNumBytes to the specified newNumBytes. Return the amount of memory available at address after the truncation.

Precondition

The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes and newNumBytes <= originalNumBytes.

Note

Note that this function will not truncate the memory unless there have been no allocations since the allocation for originalNumBytes.

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

• bslma_sequentialallocator.h