Namespace for distributed computation with MPI. More...

Functions
void	test_viewgram_slave (const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr)

void	test_viewgram_master (stir::Viewgram< float > viewgram, const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr)

void	test_image_estimate_master (const stir::DiscretisedDensity< 3, float > *input_image_ptr, int slave)

void	test_image_estimate_slave ()

void	test_related_viewgrams_master (const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr, const stir::shared_ptr< stir::DataSymmetriesForViewSegmentNumbers > symmetries_sptr, stir::RelatedViewgrams< float > *y, int slave)

void	test_related_viewgrams_slave (const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr, const stir::shared_ptr< stir::DataSymmetriesForViewSegmentNumbers > symmetries_sptr)

void	test_parameter_info_master (const std::string str, int slave, char const *const text)

void	test_parameter_info_slave (const std::string str)

void	test_bool_value_master (bool value, int slave)

void	test_bool_value_slave ()

void	test_int_value_master (int value, int slave)

void	test_int_value_slave ()

void	test_int_values_master (int slave)

void	test_int_values_slave ()

Variables
int	length

int	processor

int	iteration_counter = 0

int	image_buffer_size

MPI_Status	status

float	parameters [6]

int	sizes [6]

stir::HighResWallClockTimer	t

Tag-names currently used by functions in the distributed namespace
const int	INT_TAG = 7

const int	ARBITRARY_TAG = 8
	special tag, equivalent to MPI_ANY_TAG in some functions

const int	STIR_MPI_CONF_TAG = 9

const int	IMAGE_ESTIMATE_TAG = 23

const int	IMAGE_PARAMETER_TAG = 24

const int	VIEWGRAM_DIMENSIONS_TAG = 27

const int	VIEWGRAM_TAG = 28

const int	VIEWGRAM_COUNT_TAG = 29

const int	PROJECTION_DATA_INFO_TAG = 30

const int	PARAMETER_INFO_TAG = 21

const int	REGISTERED_NAME_TAG = 25

Global variables used for STIR_MPI
int	num_processors
	the number of processes used for distributed computation

bool	first_iteration
	some stuff in distributable_computation needs to be done only in the first iteration

bool	test = false
	enable/disable tests

bool	rpc_time = false

bool	test_send_receive_times = false
	enable timings for PRC_process_related_viewgrams_gradient() computation

double	total_rpc_time = 0
	enable timings for every single send/receive operation

double	total_rpc_time_2 = 0.0
	adding up the time used for PRC_process_related_viewgrams_gradient() computation at all slaves

double	total_rpc_time_slaves = 0.0
	adding up the time used for PRC_process_related_viewgrams_gradient() computation at a single slave

double	min_threshold = 0.1
	value to reduce the total_rpc_time values

void	send_int_value (int value, int destination)
	threshold for displaying send/receive times, initially set to 0.1 seconds More...

void	send_string (const std::string &str, int tag, int destination)
	sends or broadcasts a string More...

void	send_bool_value (bool value, int tag, int destination)
	send or broadcast a bool value More...

void	send_int_values (int *values, int count, int tag, int destination)
	sends or broadcasts some integer values More...

void	send_double_values (double *values, int count, int tag, int destination)
	send or broadcast double values More...

void	send_view_segment_numbers (const stir::ViewSegmentNumbers &vs_num, int tag, int destination)
	send or broadcast ViewSegmentNumbers object More...

void	send_projectors (const stir::shared_ptr< stir::ProjectorByBinPair > &proj_pair_sptr, int destination)
	send or broadcast a projector-pair object More...

void	send_image_parameters (const stir::DiscretisedDensity< 3, float > *input_image_ptr, int tag, int destination)
	sends or broadcasts the parameters of a DiscretisedDensity object More...

void	send_image_estimate (const stir::DiscretisedDensity< 3, float > *input_image_ptr, int destination)
	sends or broadcasts the values of a DiscretisedDensity object More...

void	send_exam_and_proj_data_info (const stir::ExamInfo &exam_info, const stir::ProjDataInfo &proj_data_info, int destination)
	sends or broadcasts the information from ExamInfo and ProjDataInfo More...

void	send_related_viewgrams (stir::RelatedViewgrams< float > *viewgrams, int destination)
	sends a RelatedViegrams object More...

void	send_viewgram (const stir::Viewgram< float > &viewgram, int destination)
	sends a Viewgram object More...

int	receive_int_value (int source)
	receives a single integer value More...

std::string	receive_string (int tag, int source)
	receives a string More...

void	receive_and_initialize_projectors (stir::shared_ptr< stir::ProjectorByBinPair > &projector_pair_ptr, int source)
	receives all needed information to subsequently construct a ProjectorByBinPair object More...

bool	receive_bool_value (int tag, int source)
	receives a bool value More...

MPI_Status	receive_int_values (int *values, int count, int tag)
	receives some integer values More...

MPI_Status	receive_double_values (double *values, int count, int tag)
	receives some double values More...

MPI_Status	receive_view_segment_numbers (stir::ViewSegmentNumbers &vs_num, int tag)
	receive a ViewSegmentNumbers object More...

void	receive_and_set_image_parameters (stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &image_ptr, int &buffer, int tag, int source)
	receives the parameters of a DiscretisedDensity object More...

MPI_Status	receive_image_values_and_fill_image_ptr (stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &image_ptr, int buffer_size, int source)
	receives the values of a DiscretisedDensity object More...

void	receive_and_construct_exam_and_proj_data_info_ptr (stir::shared_ptr< stir::ExamInfo > &exam_info_sptr, stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_sptr, int source)
	receives information of ExamInfo and ProjDataInfo objects and constructs new ones from it More...

void	receive_and_construct_related_viewgrams (stir::RelatedViewgrams< float > *&viewgrams, const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr, const stir::shared_ptr< stir::DataSymmetriesForViewSegmentNumbers > symmetries_sptr, int source)
	receives and constructs a RelatedViewgrams object More...

void	receive_and_construct_viewgram (stir::Viewgram< float > *&viewgram, const stir::shared_ptr< stir::ProjDataInfo > &proj_data_info_ptr, int source)
	receives a Viewgram object More...

void	reduce_received_output_image (stir::DiscretisedDensity< 3, float > *output_image_ptr, int destination)
	the function called by the master to reduce the output image More...

void	reduce_output_image (stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &output_image_ptr, int image_buffer_size, int my_rank, int destination)
	the function called by the slaves to reduce the output image More...

Detailed Description

Namespace for distributed computation with MPI.

This is a collection of functions to send and receive objects and data needed for distributed computation with MPI. They all come in a separate namespace "distributed". There was no need to have an object providing this functionality as that would have been more costly.

Note that every send function has a corresponding receive function.

See also: STIR_MPI; STIR_MPI_TIMINGS

Compilation instructions are in the Users Guide.

Function Documentation

◆ send_int_value()

void distributed::send_int_value	(	int	value,
		int	destination
	)

threshold for displaying send/receive times, initially set to 0.1 seconds

sends or broadcasts an integer value

Parameters

value	the int value to be sent
destination	the process id where to send the interger value. If set to -1 a Broadcast will be done

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by stir::end_distributable_computation(), stir::PoissonLogLikelihoodWithLinearModelForMeanAndListModeDataWithProjMatrixByBin< TargetT >::set_up_before_sensitivity(), and stir::setup_distributable_computation().

◆ send_string()

void distributed::send_string	(	const std::string &	str,
		int	tag,
		int	destination
	)

sends or broadcasts a string

Parameters

str	the string to be sent
tag	identifier to associate messages
destination	the process id where to send the string. If set to -1 a Broadcast will be done

References min_threshold, num_processors, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by send_projectors().

◆ send_bool_value()

void distributed::send_bool_value	(	bool	value,
		int	tag,
		int	destination
	)

send or broadcast a bool value

Parameters

value	the bool value to be sent
tag	identifier to associate messages. If the tag is -1 a Broadcast will be done
destination	the process id where to send the bool value. If set to -1 a Broadcast will be done

This function actually sends an integer value (0 or 1) as there is no bool datatype in MPI

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by stir::distributable_computation_cache_enabled().

◆ send_int_values()

void distributed::send_int_values	(	int *	values,
		int	count,
		int	tag,
		int	destination
	)

sends or broadcasts some integer values

Parameters

values	pointer to integer values to be sent
count	the count of integer values to be sent
tag	identifier to associate messages
destination	the process id where to send the int values. If set to -1 a Broadcast will be done

References min_threshold, num_processors, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by send_related_viewgrams(), send_view_segment_numbers(), and send_viewgram().

◆ send_double_values()

void distributed::send_double_values	(	double *	values,
		int	count,
		int	tag,
		int	destination
	)

send or broadcast double values

Parameters

values	pointer to the double values to be sent
count	the count of double values to be sent
tag	identifier to associate messages
destination	the process id where to send the double values. If set to -1 a Broadcast will be done

References min_threshold, num_processors, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ send_view_segment_numbers()

void distributed::send_view_segment_numbers	(	const stir::ViewSegmentNumbers &	vs_num,
		int	tag,
		int	destination
	)

send or broadcast ViewSegmentNumbers object

Parameters

vs_num	value to be sent
tag	identifier to associate messages
destination	the process id where to send the double values. If set to -1 a Broadcast will be done

References stir::SegmentIndices::segment_num(), send_int_values(), and stir::ViewgramIndices::view_num().

◆ send_projectors()

void distributed::send_projectors	(	const stir::shared_ptr< stir::ProjectorByBinPair > &	proj_pair_sptr,
		int	destination
	)

send or broadcast a projector-pair object

Parameters

proj_pair_sptr	value to be sent
destination	the process id where to send the double values. If set to -1 a Broadcast will be done

Warning: This function works by sending the parameter_info. Therefore, if file-names are used (e.g. for a projection matrix on disk) this will only work on systems with shared file systems.

References send_string().

◆ send_image_parameters()

void distributed::send_image_parameters	(	const stir::DiscretisedDensity< 3, float > *	input_image_ptr,
		int	tag,
		int	destination
	)

sends or broadcasts the parameters of a DiscretisedDensity object

Parameters

input_image_ptr	the image_ptr to be sent
tag	identifier to associate messages
destination	the process id where to send the image parameters. If set to -1 a Broadcast will be done

This function sends all parameters needed to construct a corresponding image object at the slave. The image values are sent separately. This is done, as sending the parameters is not needed everytime the values are sent. The slave needs to receive the current_image_estimate every iteration, but he already knows the parameters.

The actual parameters sent are the image dimensions, the origin and the grid_spacing

References stir::DiscretisedDensityOnCartesianGrid< 3, elemT >::get_grid_spacing(), stir::DiscretisedDensity< num_dimensions, elemT >::get_origin(), min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ send_image_estimate()

void distributed::send_image_estimate	(	const stir::DiscretisedDensity< 3, float > *	input_image_ptr,
		int	destination
	)

sends or broadcasts the values of a DiscretisedDensity object

Parameters

input_image_ptr	the image_ptr to be sent
destination	the process id where to send the image values. If set to -1 a Broadcast will be done

This function sends the values of an image. The values are serialized to a one-dimensional array as MPI only sends that kind of data structures.

References stir::Array< num_dimensions, elemT >::begin_all(), stir::Array< num_dimensions, elemT >::end_all(), min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ send_exam_and_proj_data_info()

void distributed::send_exam_and_proj_data_info	(	const stir::ExamInfo &	exam_info,
		const stir::ProjDataInfo &	proj_data_info,
		int	destination
	)

sends or broadcasts the information from ExamInfo and ProjDataInfo

Parameters

exam_info	the ExamInfo pointer to be sent
proj_data_info	the ProjDataInfo pointer to be sent
destination	the process id where to send the values. If set to -1 a Broadcast will be done

For sending the objects a rather "dirty trick" is used: Instead of sending all needed data for constructing the objects, the information is temporarily stored as ProjDataInterfile and then buffered as text from the file. Afterwards, that is sent to the slave.

Doing this, the slave is able to construct the objects by using the received information. The sent char-array is used as stream-input to the parse() function of InterfileHeader.

Warning: Creates a temporary Interfile header in the local working directory.

References stir::ProjDataInfo::create_shared_clone(), min_threshold, num_processors, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), stir::HighResWallClockTimer::value(), and stir::warning().

◆ send_related_viewgrams()

void distributed::send_related_viewgrams	(	stir::RelatedViewgrams< float > *	viewgrams,
		int	destination
	)

sends a RelatedViegrams object

Parameters

viewgrams	the viewgrams to be sent
destination	the process id where to send the related viewgrams

This function iterates through the relatedviewgrams object and calls send_viewgram() for each comprised viewgram. The only value sent is the count of viewgrams contained within the related_viewgrams object to make sure that the worker knows how many viewgrams he has to receive.

References stir::RelatedViewgrams< elemT >::begin(), stir::RelatedViewgrams< elemT >::end(), stir::RelatedViewgrams< elemT >::get_num_viewgrams(), send_int_values(), and send_viewgram().

◆ send_viewgram()

void distributed::send_viewgram	(	const stir::Viewgram< float > &	viewgram,
		int	destination
	)

sends a Viewgram object

Parameters

viewgram	the viewgrams to be sent
destination	the process id where to send the viewgram

This function sends all parameters needed for the construction of the viewgram at the worker, as well as the actual values of the viewgram. That would mean that 2 Messages are sent:

The dimensions of the viewgram and the vs_num
The values detwermined by iterating through the viewgram and serializing it to a one-dimensional array

References stir::Array< num_dimensions, elemT >::begin_all(), stir::Array< num_dimensions, elemT >::end_all(), stir::Viewgram< elemT >::get_max_axial_pos_num(), stir::Viewgram< elemT >::get_max_tangential_pos_num(), stir::Viewgram< elemT >::get_min_axial_pos_num(), stir::Viewgram< elemT >::get_min_tangential_pos_num(), stir::Viewgram< elemT >::get_segment_num(), stir::Viewgram< elemT >::get_timing_pos_num(), stir::Viewgram< elemT >::get_view_num(), min_threshold, stir::HighResWallClockTimer::reset(), send_int_values(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by send_related_viewgrams().

◆ receive_int_value()

int distributed::receive_int_value ( int source )

receives a single integer value

Parameters

source the process id from which to receive the interger value. If set to -1 the receive will be done from broadcast

Returns: the received int value

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by stir::DistributedWorker< TargetT >::start().

◆ receive_string()

std::string distributed::receive_string	(	int	tag,
		int	source
	)

receives a string

Parameters

tag	unique identifier to associate messages
source	the process id from which to receive the string

Returns: the received string

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ receive_and_initialize_projectors()

void distributed::receive_and_initialize_projectors	(	stir::shared_ptr< stir::ProjectorByBinPair > &	projector_pair_ptr,
		int	source
	)

receives all needed information to subsequently construct a ProjectorByBinPair object

Parameters

projector_pair_ptr	address pointer of the new ProjectorByBinPair pointer
source	the process id from which to receive the ProjectorByBinPair

First the registered_name string of the ProjectorByBinPair is received. Then the parameter_info() of the masters ProjectorByBinPair is received. Using the registered_name and the parameter_info() as stream, both can be used as input to the read_registered_object function, which then constructs the new ProjectorByBinPair pointer.

The passed address pointer parameter will then be redirected to the address of ProjectorByBinPair created using the received parameters.

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ receive_bool_value()

bool distributed::receive_bool_value	(	int	tag,
		int	source
	)

receives a bool value

Parameters

tag	unique identifier to associate messages
source	the process id from which to receive the bool value

Returns: the received bool value

This function actually receives an integer value (0 or 1) as there is no bool datatype in MPI, but it will return a bool value

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by stir::DistributedWorker< TargetT >::setup_distributable_computation().

◆ receive_int_values()

MPI_Status distributed::receive_int_values	(	int *	values,
		int	count,
		int	tag
	)

receives some integer values

Parameters

values	pointer to the receive buffer
count	the count of integer values to be received
tag	identifier to associate messages

Returns: MPI_Status object to query the source of the message

The tag needs to be set to ARBITRARY_TAG (=8) if MPI_ANY_TAG shall be used

References ARBITRARY_TAG, min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by receive_and_construct_related_viewgrams(), receive_and_construct_viewgram(), and receive_view_segment_numbers().

◆ receive_double_values()

MPI_Status distributed::receive_double_values	(	double *	values,
		int	count,
		int	tag
	)

receives some double values

Parameters

values	pointer to the receive buffer
count	the count of double values to be received
tag	identifier to associate messages

Returns: MPI_Status object to query the source of the message

The tag needs to be set to ARBITRARY_TAG (=8) if MPI_ANY_TAG shall be used

References ARBITRARY_TAG, min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ receive_view_segment_numbers()

MPI_Status distributed::receive_view_segment_numbers	(	stir::ViewSegmentNumbers &	vs_num,
		int	tag
	)

receive a ViewSegmentNumbers object

Parameters

[out]	vs_num	value that will be set
	tag	identifier to associate messages

Returns: MPI_Status object to query the source of the message

The tag needs to be set to ARBITRARY_TAG (=8) if MPI_ANY_TAG shall be used

References receive_int_values(), stir::SegmentIndices::segment_num(), and stir::ViewgramIndices::view_num().

◆ receive_and_set_image_parameters()

void distributed::receive_and_set_image_parameters	(	stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &	image_ptr,
		int &	buffer,
		int	tag,
		int	source
	)

receives the parameters of a DiscretisedDensity object

Parameters

image_ptr	address pointer of the new DiscretisedDensity
buffer	saves the image buffer size to be reused when receiving the image values
tag	identifier to associate messages. If set to -1 a Broadcast will be done
source	the process id from which to receive the image parameters.

This function receives all parameters needed to construct an image object at the slave. The image values are sent separately.

The actual parameters received are the image dimensions, the origin and the grid_spacing

The function currently only supports VoxelsOnCartesianGrid

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by stir::DistributedWorker< TargetT >::setup_distributable_computation().

◆ receive_image_values_and_fill_image_ptr()

MPI_Status distributed::receive_image_values_and_fill_image_ptr	(	stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &	image_ptr,
		int	buffer_size,
		int	source
	)

receives the values of a DiscretisedDensity object

Parameters

image_ptr	the image_ptr to be sent
buffer_size	gives the needed size of the receive buffer
source	the process id from which to receive the image values.

Returns: MPI_Status object to query the source of the message

The image_ptr is filled by iterating through the target pointer and copying the single values from the receive buffer.

The buffer_size is used again to reduce the image values

References stir::error(), min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ receive_and_construct_exam_and_proj_data_info_ptr()

void distributed::receive_and_construct_exam_and_proj_data_info_ptr	(	stir::shared_ptr< stir::ExamInfo > &	exam_info_sptr,
		stir::shared_ptr< stir::ProjDataInfo > &	proj_data_info_sptr,
		int	source
	)

receives information of ExamInfo and ProjDataInfo objects and constructs new ones from it

Parameters

exam_info_sptr	the new ExamInfo pointer to be set up
proj_data_info_sptr	the new ProjDataInfo pointer to be set up
source	the process id from which to receive from

The parameter info is received as a Interfile Header string. That way the slave is able to construct a ProjDataInfo within a InterfilePDFSHeader using the received char-array as stream-input to the parse() function of InterfilePDFSHeader.

References stir::error(), min_threshold, stir::KeyParser::parse(), stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ receive_and_construct_related_viewgrams()

void distributed::receive_and_construct_related_viewgrams	(	stir::RelatedViewgrams< float > *&	viewgrams,
		const stir::shared_ptr< stir::ProjDataInfo > &	proj_data_info_ptr,
		const stir::shared_ptr< stir::DataSymmetriesForViewSegmentNumbers >	symmetries_sptr,
		int	source
	)

receives and constructs a RelatedViewgrams object

Parameters

viewgrams	object that will be filled with the data
proj_data_info_ptr	the ProjDataInfo pointer describing the data
symmetries_sptr	the symmetries pointer constructed when setting up the projectors
source	the process id from which to receive the ProjDataInfo

First of all it is important to notice, that this function is not independent. To construct a new RelatedViegrams object, the symmetries_ptr must be available. That would mean, that the slave has to call receive_and_initialize_projectors() to set up the symmetries_ptr before the related_vewgrams can be received. Additionally the ProjDataInfo-pointer must be available for receiving a single viewgrams. That implies calling receive_and_construct_proj_data_info_ptr() before. To make this function independent, both of these objects have to be sent here. On the other hand that would lead to the overhead of sending it everytime a related_viewgram is sent, which is really expensive.

This function receives the count of viewgrams to be received and calls receive_and_construct_viewgram that often. Every received viewgram is pushed back to a viewgram vector, which afterwards is used with the symmetries to construct a RelatedViewgrams object.

References receive_and_construct_viewgram(), and receive_int_values().

◆ receive_and_construct_viewgram()

void distributed::receive_and_construct_viewgram	(	stir::Viewgram< float > *&	viewgram,
		const stir::shared_ptr< stir::ProjDataInfo > &	proj_data_info_ptr,
		int	source
	)

receives a Viewgram object

Parameters

viewgram	the viewgrams to be constructed
proj_data_info_ptr	the ProjDataInfo pointer describing the data
source	the process id from which to receive the ProjDataInfo

This function received all parameters needed for the construction of the viewgram at the worker, as well as the actual values of the viewgram. That would mean that 2 Messages are received:

The dimensions of the viewgram and the vs_num
The values of the viewgram

The buffer_size needed to receive the values is calculated from the dimensions received. The viewgram is filled by iterating througn it and copying the values of the received values.

References stir::Array< num_dimensions, elemT >::begin_all(), min_threshold, receive_int_values(), stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Referenced by receive_and_construct_related_viewgrams().

◆ reduce_received_output_image()

void distributed::reduce_received_output_image	(	stir::DiscretisedDensity< 3, float > *	output_image_ptr,
		int	destination
	)

the function called by the master to reduce the output image

Parameters

output_image_ptr	the image pointer where the reduced image is saved
destination	the process id where the output_image is reduced

References stir::Array< num_dimensions, elemT >::begin_all(), min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

◆ reduce_output_image()

void distributed::reduce_output_image	(	stir::shared_ptr< stir::DiscretisedDensity< 3, float >> &	output_image_ptr,
		int	image_buffer_size,
		int	my_rank,
		int	destination
	)

the function called by the slaves to reduce the output image

Parameters

output_image_ptr	the image pointer where the reduced image is saved
image_buffer_size	the buffer size needed for the image
my_rank	rank of the slave, only used for screen output
destination	the process id where the output_image is reduced

The buffer size was calculated in receive_image_values_and_fill_image_ptr(). Alternatively it can be calculated by the image parameters.

References min_threshold, stir::HighResWallClockTimer::reset(), stir::HighResWallClockTimer::start(), stir::HighResWallClockTimer::stop(), and stir::HighResWallClockTimer::value().

Functions

Variables

Global variables used for STIR_MPI

Detailed Description

Function Documentation

◆ send_int_value()

◆ send_string()

◆ send_bool_value()

◆ send_int_values()

◆ send_double_values()

◆ send_view_segment_numbers()

◆ send_projectors()

◆ send_image_parameters()

◆ send_image_estimate()

◆ send_exam_and_proj_data_info()

◆ send_related_viewgrams()

◆ send_viewgram()

◆ receive_int_value()

◆ receive_string()

◆ receive_and_initialize_projectors()

◆ receive_bool_value()

◆ receive_int_values()

◆ receive_double_values()

◆ receive_view_segment_numbers()

◆ receive_and_set_image_parameters()

◆ receive_image_values_and_fill_image_ptr()

◆ receive_and_construct_exam_and_proj_data_info_ptr()

◆ receive_and_construct_related_viewgrams()

◆ receive_and_construct_viewgram()

◆ reduce_received_output_image()

◆ reduce_output_image()