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Public Member Functions

bslma::SequentialPool Class Reference

#include <bslma_sequentialpool.h>

List of all members.

Public Member Functions

 SequentialPool (Allocator *basicAllocator=0)
 SequentialPool (BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
 SequentialPool (int initialSize, Allocator *basicAllocator=0)
 SequentialPool (int initialSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
 SequentialPool (char *buffer, int bufferSize, Allocator *basicAllocator=0)
 SequentialPool (char *buffer, int bufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
 SequentialPool (int initialSize, int maxBufferSize, Allocator *basicAllocator=0)
 SequentialPool (int initialSize, int maxBufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
 SequentialPool (char *buffer, int bufferSize, int maxBufferSize, Allocator *basicAllocator=0)
 SequentialPool (char *buffer, int bufferSize, int maxBufferSize, BufferAllocator::AlignmentStrategy strategy, Allocator *basicAllocator=0)
 ~SequentialPool ()
void * allocate (int size)
void * allocateAndExpand (int *size)
void * allocateAndExpand (int *size, int maxNumBytes)
template<class TYPE >
void deleteObject (const TYPE *object)
template<class TYPE >
void deleteObjectRaw (const TYPE *object)
int expand (void *address, int originalNumBytes)
int expand (void *address, int originalNumBytes, int maxNumBytes)
void release ()
void reserveCapacity (int numBytes)
int truncate (void *address, int originalNumBytes, int newNumBytes)

Detailed Description

This class implements a memory pool that dispenses arbitrarily-sized blocks of memory from an internal buffer or an optionally user-supplied buffer. If an allocation request exceeds the remaining free memory space in the current buffer, the pool either replenishes its buffer with new memory to satisfy the request, or returns a separate memory block, depending on whether the request size exceeds an optionally specified maximum buffer size. By default, buffer growth is not capped. The release method releases all memory allocated through this pool, as does the destructor. Note, however, that individual allocated blocks of memory cannot be individually deallocated.

See Component bslma_sequentialpool


Constructor & Destructor Documentation

bslma::SequentialPool::SequentialPool ( Allocator basicAllocator = 0  )  [explicit]
bslma::SequentialPool::SequentialPool ( BufferAllocator::AlignmentStrategy  strategy,
Allocator basicAllocator = 0 
) [explicit]
bslma::SequentialPool::SequentialPool ( int  initialSize,
Allocator basicAllocator = 0 
) [explicit]
bslma::SequentialPool::SequentialPool ( int  initialSize,
BufferAllocator::AlignmentStrategy  strategy,
Allocator basicAllocator = 0 
)

Create a sequential pool 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.

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

Create a sequential pool 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.

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

Create a sequential pool 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. The behavior is undefined unless 0 < maxBufferSize, and |initialSize| <= maxBufferSize. 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.

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

Create a sequential pool 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. The behavior is undefined unless 0 < maxBufferSize, and |bufferSize| <= maxBufferSize. 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.

bslma::SequentialPool::~SequentialPool (  ) 

Destroy this object and release all memory currently allocated through this pool.


Member Function Documentation

void* bslma::SequentialPool::allocate ( int  size  ) 

Return memory of the specified size. If size is 0, no memory is allocated and 0 is returned. The behavior is undefined unless 0 <= size.

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

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

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

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

template<class TYPE >
void bslma::SequentialPool::deleteObject ( const TYPE *  object  ) 

Destroy the specified object. Note that this method is exactly the same as the deleteObjectRaw method since no deallocation is involved. This method exists purely for consistency across pools.

template<class TYPE >
void bslma::SequentialPool::deleteObjectRaw ( const TYPE *  object  ) 

Destroy the specified object. Note that the memory is not deallocated because there is no deallocate method in a bslma_sequentialpool.

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

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. The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes. Note that this function will not expand the memory unless there have been no allocations since the allocation for originalNumBytes.

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

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. The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes and originalNumBytes < maxNumBytes. Note that this function will not expand the memory unless there have been no allocations since the allocation for originalNumBytes.

void bslma::SequentialPool::release (  ) 

Release all memory currently allocated through this pool.

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

Reserve sufficient memory to satisfy allocation requests for at least the specified numBytes without replenishment (i.e., without internal allocation). The behavior is undefined unless 0 <= numBytes.

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

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. The behavior is undefined unless the call to this allocator that provided the address was performed with the originalNumBytes and newNumBytes <= originalNumBytes. Note that this function will not truncate the memory unless there have been no allocations since the allocation for originalNumBytes.


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