The NDArrayPool class manages a free list (pool) of NDArray objects. More...

#include <NDArray.h>

Public Member Functions
	NDArrayPool (class asynNDArrayDriver *pDriver, size_t maxMemory)
	NDArrayPool constructor. More...

virtual	~NDArrayPool ()

NDArray *	alloc (int ndims, size_t dims, NDDataType_t dataType, size_t dataSize, void pData)
	Allocates a new NDArray object; the first 3 arguments are required. More...

NDArray *	copy (NDArray pIn, NDArray pOut, bool copyData, bool copyDimensions=true, bool copyDataType=true)
	This method makes a copy of an NDArray object. More...

int	reserve (NDArray *pArray)
	This method increases the reference count for the NDArray object. More...

int	release (NDArray *pArray)
	This method decreases the reference count for the NDArray object. More...

int	convert (NDArray pIn, NDArray ppOut, NDDataType_t dataTypeOut, NDDimension_t outDims)
	Creates a new output NDArray from an input NDArray, performing conversion operations. More...

int	convert (NDArray pIn, NDArray *ppOut, NDDataType_t dataTypeOut)
	Creates a new output NDArray from an input NDArray, performing conversion operations. More...

int	report (FILE *fp, int details)
	Reports on the free list size and other properties of the NDArrayPool object. More...

int	getNumBuffers ()
	Returns number of buffers this object has currently allocated. More...

size_t	getMaxMemory ()
	Returns maximum bytes of memory this object is allowed to allocate; 0=unlimited. More...

size_t	getMemorySize ()
	Returns mumber of bytes of memory this object has currently allocated. More...

int	getNumFree ()
	Returns number of NDArray objects in the free list. More...

void	emptyFreeList ()
	Deletes all of the NDArrays in the free list. More...

Protected Member Functions
virtual NDArray *	createArray ()
	The following methods should be implemented by a pool class that manages objects derived from the NDArray class. More...

virtual void	onAllocateArray (NDArray *pArray)
	Hook for pool classes that manage objects derived from NDArray class. More...

virtual void	onReserveArray (NDArray *pArray)
	Hook for pool classes that manage objects derived from NDArray class. More...

virtual void	onReleaseArray (NDArray *pArray)
	Hook for pool classes that manage objects derived from NDArray class. More...

Detailed Description

The NDArrayPool class manages a free list (pool) of NDArray objects.

Drivers allocate NDArray objects from the pool, and pass these objects to plugins. Plugins increase the reference count on the object when they place the object on their queue, and decrease the reference count when they are done processing the array. When the reference count reaches 0 again the NDArray object is placed back on the free list. This mechanism minimizes the copying of array data in plugins.

Constructor & Destructor Documentation

NDArrayPool::NDArrayPool	(	class asynNDArrayDriver *	pDriver,
		size_t	maxMemory
	)

NDArrayPool constructor.

Parameters

[in]	pDriver	Pointer to the asynNDArrayDriver that created this object.
[in]	maxMemory	Maxiumum number of bytes of memory the the pool is allowed to use, summed over all of the NDArray objects; 0=unlimited.

virtual NDArrayPool::~NDArrayPool ( )

inlinevirtual

Member Function Documentation

NDArray * NDArrayPool::alloc	(	int	ndims,
		size_t *	dims,
		NDDataType_t	dataType,
		size_t	dataSize,
		void *	pData
	)

Allocates a new NDArray object; the first 3 arguments are required.

Parameters

[in]	ndims	The number of dimensions in the NDArray.
[in]	dims	Array of dimensions, whose size must be at least ndims.
[in]	dataType	Data type of the NDArray data.
[in]	dataSize	Number of bytes to allocate for the array data; if 0 then alloc() will compute the size required from ndims, dims, and dataType.
[in]	pData	Pointer to a data buffer; if NULL then alloc will allocate a new array buffer; if not NULL then it is assumed to point to a valid buffer.

If pData is not NULL then dataSize must contain the actual number of bytes in the existing array, and this array must be large enough to hold the array data. alloc() searches its free list to find a free NDArray buffer. If is cannot find one then it will allocate a new one and add it to the free list. If allocating the memory required for this NDArray would cause the cumulative memory allocated for the pool to exceed maxMemory then an error will be returned. alloc() sets the reference count for the returned NDArray to 1.

int NDArrayPool::convert	(	NDArray *	pIn,
		NDArray **	ppOut,
		NDDataType_t	dataTypeOut,
		NDDimension_t *	dimsOut
	)

Creates a new output NDArray from an input NDArray, performing conversion operations.

The conversion can change the data type if dataTypeOut is different from pIn->dataType. It can also change the dimensions. outDims may have different values of size, binning, offset and reverse for each of its dimensions from input array dimensions (pIn->dims).

Parameters

[in]	pIn	The input array, source of the conversion.
[out]	ppOut	The output array, result of the conversion.
[in]	dataTypeOut	The data type of the output array.
[in]	dimsOut	The dimensions of the output array.

int NDArrayPool::convert	(	NDArray *	pIn,
		NDArray **	ppOut,
		NDDataType_t	dataTypeOut
	)

Creates a new output NDArray from an input NDArray, performing conversion operations.

This form of the function is for changing the data type only, not the dimensions, which are preserved.

Parameters

[in]	pIn	The input array, source of the conversion.
[out]	ppOut	The output array, result of the conversion.
[in]	dataTypeOut	The data type of the output array.

NDArray * NDArrayPool::copy	(	NDArray *	pIn,
		NDArray *	pOut,
		bool	copyData,
		bool	copyDimensions = `true`,
		bool	copyDataType = `true`
	)

This method makes a copy of an NDArray object.

Parameters

[in]	pIn	The input array to be copied.
[in]	pOut	The output array that will be copied to; can be NULL or a pointer to an existing NDArray.
[in]	copyData	If this flag is true then everything including the array data is copied; if 0 then everything except the data (including attributes) is copied.
[in]	copyDimensions	If this flag is true then the dimensions are copied even if pOut is not NULL; default=true.
[in]	copyDataType	If this flag is true then the dataType is copied even if pOut is not NULL; default=true.

Returns: Returns a pointer to the output array.

If pOut is NULL then it is first allocated. If the output array object already exists (pOut!=NULL) then it must have sufficient memory allocated to it to hold the data.

NDArray * NDArrayPool::createArray ( )

protectedvirtual

The following methods should be implemented by a pool class that manages objects derived from the NDArray class.

Create new NDArray object.

This method should be overriden by a pool class that manages objects that derive from NDArray class.

void NDArrayPool::emptyFreeList ( )

Deletes all of the NDArrays in the free list.

size_t NDArrayPool::getMaxMemory ( )

Returns maximum bytes of memory this object is allowed to allocate; 0=unlimited.

size_t NDArrayPool::getMemorySize ( )

Returns mumber of bytes of memory this object has currently allocated.

int NDArrayPool::getNumBuffers ( )

Returns number of buffers this object has currently allocated.

int NDArrayPool::getNumFree ( )

Returns number of NDArray objects in the free list.

void NDArrayPool::onAllocateArray ( NDArray * pArray )

protectedvirtual

Hook for pool classes that manage objects derived from NDArray class.

This hook is called after new array has been allocated.

Parameters

[in] pArray Pointer to the allocated NDArray object

void NDArrayPool::onReleaseArray ( NDArray * pArray )

protectedvirtual

Hook for pool classes that manage objects derived from NDArray class.

This hook is called after array has been released.

Parameters

[in] pArray Pointer to the released NDArray object

void NDArrayPool::onReserveArray ( NDArray * pArray )

protectedvirtual

Hook for pool classes that manage objects derived from NDArray class.

This hook is called after array has been reserved.

Parameters

[in] pArray Pointer to the reserved NDArray object

int NDArrayPool::release ( NDArray * pArray )

This method decreases the reference count for the NDArray object.

Parameters

[in] pArray The array on which to decrease the reference count.

When the reference count reaches 0 the NDArray is placed back in the free list. Plugins must call release() when an NDArray is removed from the queue and processing on it is complete. Drivers must call release() after calling all plugins.

int NDArrayPool::report	(	FILE *	fp,
		int	details
	)

Reports on the free list size and other properties of the NDArrayPool object.

Parameters

[in]	fp	File pointer for the report output.
[in]	details	Level of report details desired; does nothing at present.

int NDArrayPool::reserve ( NDArray * pArray )

This method increases the reference count for the NDArray object.

Parameters

[in] pArray The array on which to increase the reference count.

Plugins must call reserve() when an NDArray is placed on a queue for later processing.

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

/home/epics/devel/areaDetector/ADCore/ADApp/ADSrc/NDArray.h
/home/epics/devel/areaDetector/ADCore/ADApp/ADSrc/NDArrayPool.cpp

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation