starpu-max/doc/doxygen/chapters/api/data_interfaces.doxy

/*
 * This file is part of the StarPU Handbook.
 * Copyright (C) 2009--2011  Universit@'e de Bordeaux 1
 * Copyright (C) 2010, 2011, 2012, 2013  Centre National de la Recherche Scientifique
 * Copyright (C) 2011, 2012 Institut National de Recherche en Informatique et Automatique
 * See the file version.doxy for copying conditions.
 */

/*! \defgroup Data_Interfaces Data Interfaces

\struct starpu_data_interface_ops
\brief Per-interface data transfer methods.
\ingroup Data_Interfaces
\var starpu_data_interface_ops::register_data_handle
Register an existing interface into a data handle.
\var starpu_data_interface_ops::allocate_data_on_node
Allocate data for the interface on a given node.
\var starpu_data_interface_ops::free_data_on_node
Free data of the interface on a given node.
\var starpu_data_interface_ops::copy_methods
ram/cuda/opencl synchronous and asynchronous transfer methods.
\var starpu_data_interface_ops::handle_to_pointer
Return the current pointer (if any) for the handle on the given node.
\var starpu_data_interface_ops::get_size
Return an estimation of the size of data, for performance models.
\var starpu_data_interface_ops::footprint
Return a 32bit footprint which characterizes the data size.
\var starpu_data_interface_ops::compare
Compare the data size of two interfaces.
\var starpu_data_interface_ops::display
Dump the sizes of a handle to a file.
\var starpu_data_interface_ops::interfaceid
An identifier that is unique to each interface.
\var starpu_data_interface_ops::interface_size
The size of the interface data descriptor.
\var starpu_data_interface_ops::is_multiformat
todo
\var starpu_data_interface_ops::get_mf_ops
todo
\var starpu_data_interface_ops::pack_data
Pack the data handle into a contiguous buffer at the address ptr and
set the size of the newly created buffer in count. If ptr is NULL, the
function should not copy the data in the buffer but just set count to
the size of the buffer which would have been allocated. The special
value -1 indicates the size is yet unknown.
\var starpu_data_interface_ops::unpack_data
Unpack the data handle from the contiguous buffer at the address ptr
of size count

\struct starpu_data_copy_methods
\brief Defines the per-interface methods.

If the any_to_any method is
provided, it will be used by default if no more specific method is
provided. It can still be useful to provide more specific method in
case of e.g. available particular CUDA or OpenCL support.
\ingroup Data_Interfaces
\var starpu_data_copy_methods::ram_to_ram
Define how to copy data from the src_interface interface on the
src_node CPU node to the dst_interface interface on the dst_node CPU
node. Return 0 on success.
\var starpu_data_copy_methods::ram_to_cuda
Define how to copy data from the src_interface interface on the
src_node CPU node to the dst_interface interface on the dst_node CUDA
node. Return 0 on success.
\var starpu_data_copy_methods::ram_to_opencl
Define how to copy data from the src_interface interface on the
src_node CPU node to the dst_interface interface on the dst_node
OpenCL node. Return 0 on success.
\var starpu_data_copy_methods::cuda_to_ram
Define how to copy data from the src_interface interface on the
src_node CUDA node to the dst_interface interface on the dst_node
CPU node. Return 0 on success.
\var starpu_data_copy_methods::cuda_to_cuda
Define how to copy data from the src_interface interface on the
src_node CUDA node to the dst_interface interface on the dst_node CUDA
node. Return 0 on success.
\var starpu_data_copy_methods::cuda_to_opencl
Define how to copy data from the src_interface interface on the
src_node CUDA node to the dst_interface interface on the dst_node
OpenCL node. Return 0 on success.
\var starpu_data_copy_methods::opencl_to_ram
Define how to copy data from the src_interface interface on the
src_node OpenCL node to the dst_interface interface on the dst_node
CPU node. Return 0 on success.
\var starpu_data_copy_methods::opencl_to_cuda
Define how to copy data from the src_interface interface on the
src_node OpenCL node to the dst_interface interface on the dst_node
CUDA node. Return 0 on success.
\var starpu_data_copy_methods::opencl_to_opencl
Define how to copy data from the src_interface interface on the
src_node OpenCL node to the dst_interface interface on the dst_node
OpenCL node. Return 0 on success.

\var starpu_data_copy_methods::ram_to_cuda_async
Define how to copy data from the src_interface interface on the
src_node CPU node to the dst_interface interface on the dst_node CUDA
node, using the given stream. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the core.
\var starpu_data_copy_methods::cuda_to_ram_async
Define how to copy data from the src_interface interface on the
src_node CUDA node to the dst_interface interface on the dst_node CPU
node, using the given stream. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the core.
\var starpu_data_copy_methods::cuda_to_cuda_async
Define how to copy data from the src_interface interface on the
src_node CUDA node to the dst_interface interface on the dst_node CUDA
node, using the given stream. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the core.

\var starpu_data_copy_methods::ram_to_opencl_async
Define how to copy data from the src_interface interface on the
src_node CPU node to the dst_interface interface on the dst_node
OpenCL node, by recording in event, a pointer to a cl_event, the event
of the last submitted transfer. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the
core.
\var starpu_data_copy_methods::opencl_to_ram_async
Define how to copy data from the src_interface interface on the
src_node OpenCL node to the dst_interface interface on the dst_node
CPU node, by recording in event, a pointer to a cl_event, the event of
the last submitted transfer. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the
core.
\var starpu_data_copy_methods::opencl_to_opencl_async
Define how to copy data from the src_interface interface on the
src_node OpenCL node to the dst_interface interface on the dst_node
OpenCL node, by recording in event, a pointer to a cl_event, the event
of the last submitted transfer. Must return 0 if the transfer was
actually completed completely synchronously, or -EAGAIN if at least
some transfers are still ongoing and should be awaited for by the
core.

\var starpu_data_copy_methods::any_to_any
Define how to copy data from the src_interface interface on the
src_node node to the dst_interface interface on the dst_node node.
This is meant to be implemented through the starpu_interface_copy()
helper, to which async_data should be passed as such, and will be used
to manage asynchronicity. This must return -EAGAIN if any of the
starpu_interface_copy() calls has returned -EAGAIN (i.e. at least some
transfer is still ongoing), and return 0 otherwise.

@name Registering Data
\ingroup Data_Interfaces

There are several ways to register a memory region so that it can be
managed by StarPU. The functions below allow the registration of
vectors, 2D matrices, 3D matrices as well as BCSR and CSR sparse
matrices.

\fn void starpu_void_data_register(starpu_data_handle_t *handle)
\ingroup Data_Interfaces
Register a void interface. There is no data really associated
to that interface, but it may be used as a synchronization mechanism.
It also permits to express an abstract piece of data that is managed
by the application internally: this makes it possible to forbid the
concurrent execution of different tasks accessing the same <c>void</c> data
in read-write concurrently. 

\fn void starpu_variable_data_register(starpu_data_handle_t *handle, unsigned home_node, uintptr_t ptr, size_t size)
\ingroup Data_Interfaces
Register the \p size byte element pointed to by \p ptr, which is
typically a scalar, and initialize \p handle to represent this data item.

Here an example of how to use the function.
\code{.c}
float var;
starpu_data_handle_t var_handle;
starpu_variable_data_register(&var_handle, 0, (uintptr_t)&var, sizeof(var));
\endcode

\fn void starpu_vector_data_register(starpu_data_handle_t *handle, unsigned home_node, uintptr_t ptr, uint32_t nx, size_t elemsize)
\ingroup Data_Interfaces
Register the \p nx elemsize-byte elements pointed to by \p ptr and initialize \p handle to represent it.

Here an example of how to use the function.
\code{.c}
float vector[NX];
starpu_data_handle_t vector_handle;
starpu_vector_data_register(&vector_handle, 0, (uintptr_t)vector, NX, sizeof(vector[0]));
\endcode

\fn void starpu_matrix_data_register(starpu_data_handle_t *handle, unsigned home_node, uintptr_t ptr, uint32_t ld, uint32_t nx, uint32_t ny, size_t elemsize)
\ingroup Data_Interfaces
Register the \p nx x \p  ny 2D matrix of \p elemsize-byte elements pointed
by \p ptr and initialize \p handle to represent it. \p ld specifies the number
of elements between rows. a value greater than \p nx adds padding, which
can be useful for alignment purposes.

Here an example of how to use the function.
\code{.c}
float *matrix;
starpu_data_handle_t matrix_handle;
matrix = (float*)malloc(width * height * sizeof(float));
starpu_matrix_data_register(&matrix_handle, 0, (uintptr_t)matrix, width, width, height, sizeof(float));
\endcode

\fn void starpu_block_data_register(starpu_data_handle_t *handle, unsigned home_node, uintptr_t ptr, uint32_t ldy, uint32_t ldz, uint32_t nx, uint32_t ny, uint32_t nz, size_t elemsize)
\ingroup Data_Interfaces
Register the \p nx x \p ny x \p nz 3D matrix of \p elemsize byte elements
pointed by \p ptr and initialize \p handle to represent it. Again, \p ldy and
\p ldz specify the number of elements between rows and between z planes.

Here an example of how to use the function.
\code{.c}
float *block;
starpu_data_handle_t block_handle;
block = (float*)malloc(nx*ny*nz*sizeof(float));
starpu_block_data_register(&block_handle, 0, (uintptr_t)block, nx, nx*ny, nx, ny, nz, sizeof(float));
\endcode

\fn void starpu_bcsr_data_register(starpu_data_handle_t *handle, unsigned home_node, uint32_t nnz, uint32_t nrow, uintptr_t nzval, uint32_t *colind, uint32_t *rowptr, uint32_t firstentry, uint32_t r, uint32_t c, size_t elemsize)
\ingroup Data_Interfaces
This variant of starpu_data_register() uses the BCSR (Blocked
Compressed Sparse Row Representation) sparse matrix interface.
Register the sparse matrix made of \p nnz non-zero blocks of elements of
size \p elemsize stored in \p nzval and initializes \p handle to represent it.
Blocks have size \p r * \p c. \p nrow is the number of rows (in terms of
blocks), \p colind[i] is the block-column index for block i in \p nzval,
\p rowptr[i] is the block-index (in \p nzval) of the first block of row i.
\p firstentry is the index of the first entry of the given arrays
(usually 0 or 1). 

\fn void starpu_csr_data_register(starpu_data_handle_t *handle, unsigned home_node, uint32_t nnz, uint32_t nrow, uintptr_t nzval, uint32_t *colind, uint32_t *rowptr, uint32_t firstentry, size_t elemsize)
\ingroup Data_Interfaces
This variant of starpu_data_register() uses the CSR (Compressed
Sparse Row Representation) sparse matrix interface. TODO

\fn void starpu_coo_data_register(starpu_data_handle_t *handleptr, unsigned home_node, uint32_t nx, uint32_t ny, uint32_t n_values, uint32_t *columns, uint32_t *rows, uintptr_t values, size_t elemsize);
\ingroup Data_Interfaces
Register the \p nx x \p ny 2D matrix given in the COO format, using the
\p columns, \p rows, \p values arrays, which must have \p n_values elements of
size \p elemsize. Initialize \p handleptr.

\fn void *starpu_data_get_interface_on_node(starpu_data_handle_t handle, unsigned memory_node)
\ingroup Data_Interfaces
Return the interface associated with \p handle on \p memory_node.

@name Accessing Data Interfaces
\ingroup Data_Interfaces

Each data interface is provided with a set of field access functions.
The ones using a void * parameter aimed to be used in codelet
implementations (see for example the code in \ref
Vector_Scaling_Using_StarPU_API).

\fn void *starpu_data_handle_to_pointer(starpu_data_handle_t handle, unsigned node)
\ingroup Data_Interfaces
Return the pointer associated with \p handle on node \p node or <c>NULL</c>
if handle’s interface does not support this operation or data for this
\p handle is not allocated on that \p node.

\fn void *starpu_data_get_local_ptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the local pointer associated with \p handle or <c>NULL</c> if
\p handle’s interface does not have data allocated locally 

\fn enum starpu_data_interface_id starpu_data_get_interface_id(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the unique identifier of the interface associated with
the given \p handle.

\fn size_t starpu_data_get_size(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the data associated with \p handle.

\fn int starpu_data_pack(starpu_data_handle_t handle, void **ptr, starpu_ssize_t *count)
\ingroup Data_Interfaces
Execute the packing operation of the interface of the data
registered at \p handle (see starpu_data_interface_ops). This
packing operation must allocate a buffer large enough at \p ptr and copy
into the newly allocated buffer the data associated to \p handle. \p count
will be set to the size of the allocated buffer. If \p ptr is NULL, the
function should not copy the data in the buffer but just set \p count to
the size of the buffer which would have been allocated. The special
value -1 indicates the size is yet unknown.

\fn int starpu_data_unpack(starpu_data_handle_t handle, void *ptr, size_t count)
\ingroup Data_Interfaces
Unpack in handle the data located at \p ptr of size \p count as
described by the interface of the data. The interface registered at
\p handle must define a unpacking operation (see
starpu_data_interface_ops). The memory at the address \p ptr is freed
after calling the data unpacking operation.

@name Accessing Variable Data Interfaces
\ingroup Data_Interfaces

\struct starpu_variable_interface
\brief Variable interface for a single data (not a vector, a matrix, a list, ...)
\ingroup Data_Interfaces
\var starpu_variable_interface::id
Identifier of the interface
\var starpu_variable_interface::ptr
local pointer of the variable
\var starpu_variable_interface::dev_handle
device handle of the variable.
\var starpu_variable_interface::offset
offset in the variable
\var starpu_variable_interface::elemsize
size of the variable

\fn size_t starpu_variable_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the variable designated by \p handle.

\fn uintptr_t starpu_variable_get_local_ptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a pointer to the variable designated by \p handle.

\def STARPU_VARIABLE_GET_PTR(interface)
\ingroup Data_Interfaces
Return a pointer to the variable designated by \p interface.

\def STARPU_VARIABLE_GET_ELEMSIZE(interface)
\ingroup Data_Interfaces
Return the size of the variable designated by \p interface.

\def STARPU_VARIABLE_GET_DEV_HANDLE(interface)
\ingroup Data_Interfaces
Return a device handle for the variable designated by
\p interface, to be used on OpenCL. The offset documented below has to be
used in addition to this.

\def STARPU_VARIABLE_GET_OFFSET()
\ingroup Data_Interfaces
Return the offset in the variable designated by \p interface, to
be used with the device handle.

@name Accessing Vector Data Interfaces
\ingroup Data_Interfaces

\struct starpu_vector_interface
\brief Vector interface
\ingroup Data_Interfaces
\var starpu_vector_interface::id
Identifier of the interface
\var starpu_vector_interface::ptr
local pointer of the vector
\var starpu_vector_interface::dev_handle
device handle of the vector.
\var starpu_vector_interface::offset
offset in the vector
\var starpu_vector_interface::nx
number of elements on the x-axis of the vector
\var starpu_vector_interface::elemsize
size of the elements of the vector

\fn uint32_t starpu_vector_get_nx(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements registered into the array designated by \p handle.

\fn size_t starpu_vector_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of each element of the array designated by \p handle.

\fn uintptr_t starpu_vector_get_local_ptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the local pointer associated with \p handle.

\def STARPU_VECTOR_GET_PTR(void *interface)
\ingroup Data_Interfaces
Return a pointer to the array designated by \p interface, valid on
CPUs and CUDA only. For OpenCL, the device handle and offset need to
be used instead.

\def STARPU_VECTOR_GET_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the array designated by \p interface,
to be used on OpenCL. the offset documented below has to be used in
addition to this.

\def STARPU_VECTOR_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the array designated by \p interface, to be
used with the device handle.

\def STARPU_VECTOR_GET_NX(void *interface)
\ingroup Data_Interfaces
Return the number of elements registered into the array
designated by \p interface.

\def STARPU_VECTOR_GET_ELEMSIZE(void *interface)
\ingroup Data_Interfaces
Return the size of each element of the array designated by
\p interface.

@name Accessing Matrix Data Interfaces
\ingroup Data_Interfaces

\struct starpu_matrix_interface
\brief Matrix interface for dense matrices
\ingroup Data_Interfaces
\var starpu_matrix_interface::id
Identifier of the interface
\var starpu_matrix_interface::ptr
local pointer of the matrix
\var starpu_matrix_interface::dev_handle
device handle of the matrix.
\var starpu_matrix_interface::offset
offset in the matrix
\var starpu_matrix_interface::nx
number of elements on the x-axis of the matrix
\var starpu_matrix_interface::ny
number of elements on the y-axis of the matrix
\var starpu_matrix_interface::ld
number of elements between each row of the matrix. Maybe be equal to
starpu_matrix_interface::nx when there is no padding.
\var starpu_matrix_interface::elemsize
size of the elements of the matrix

\fn uint32_t starpu_matrix_get_nx(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements on the x-axis of the matrix
designated by \p handle.

\fn uint32_t starpu_matrix_get_ny(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements on the y-axis of the matrix
designated by \p handle.

\fn uint32_t starpu_matrix_get_local_ld(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements between each row of the matrix
designated by \p handle. Maybe be equal to nx when there is no padding.

\fn uintptr_t starpu_matrix_get_local_ptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the local pointer associated with \p handle.

\fn size_t starpu_matrix_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the elements registered into the matrix
designated by \p handle.

\def STARPU_MATRIX_GET_PTR(void *interface)
\ingroup Data_Interfaces
Return a pointer to the matrix designated by \p interface, valid
on CPUs and CUDA devices only. For OpenCL devices, the device handle
and offset need to be used instead.

\def STARPU_MATRIX_GET_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the matrix designated by \p interface,
to be used on OpenCL. The offset documented below has to be used in
addition to this.

\def STARPU_MATRIX_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the matrix designated by \p interface, to be
used with the device handle.

\def STARPU_MATRIX_GET_NX(void *interface)
\ingroup Data_Interfaces
Return the number of elements on the x-axis of the matrix
designated by \p interface.

\def STARPU_MATRIX_GET_NY(void *interface)
\ingroup Data_Interfaces
Return the number of elements on the y-axis of the matrix
designated by \p interface.

\def STARPU_MATRIX_GET_LD(void *interface)
\ingroup Data_Interfaces
Return the number of elements between each row of the matrix
designated by \p interface. May be equal to nx when there is no padding.

\def STARPU_MATRIX_GET_ELEMSIZE(void *interface)
\ingroup Data_Interfaces
Return the size of the elements registered into the matrix
designated by \p interface.

@name Accessing Block Data Interfaces
\ingroup Data_Interfaces

\struct starpu_block_interface
\brief Block interface for 3D dense blocks
\ingroup Data_Interfaces
\struct starpu_block_interface::id
identifier of the interface
\var starpu_block_interface::ptr
local pointer of the block
\var starpu_block_interface::dev_handle
device handle of the block.
\var starpu_block_interface::offset
offset in the block.
\var starpu_block_interface::nx
number of elements on the x-axis of the block.
\var starpu_block_interface::ny
number of elements on the y-axis of the block.
\var starpu_block_interface::nz
number of elements on the z-axis of the block.
\var starpu_block_interface::ldy
number of elements between two lines
\var starpu_block_interface::ldz
number of elements between two planes
\var starpu_block_interface::elemsize
size of the elements of the block.

\fn uint32_t starpu_block_get_nx(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements on the x-axis of the block
designated by \p handle.

\fn uint32_t starpu_block_get_ny(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements on the y-axis of the block
designated by \p handle.

\fn uint32_t starpu_block_get_nz(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements on the z-axis of the block
designated by \p handle.

\fn uint32_t starpu_block_get_local_ldy(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements between each row of the block
designated by \p handle, in the format of the current memory node.

\fn uint32_t starpu_block_get_local_ldz(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of elements between each z plane of the block
designated by \p handle, in the format of the current memory node.

\fn uintptr_t starpu_block_get_local_ptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the local pointer associated with \p handle.

\fn size_t starpu_block_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the elements of the block designated by
\p handle.

\def STARPU_BLOCK_GET_PTR(void *interface)
\ingroup Data_Interfaces
Return a pointer to the block designated by \p interface.

\def STARPU_BLOCK_GET_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the block designated by \p interface,
to be used on OpenCL. The offset document below has to be used in
addition to this.

\def STARPU_BLOCK_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the block designated by \p interface, to be
used with the device handle.

\def STARPU_BLOCK_GET_NX(void *interface)
\ingroup Data_Interfaces
Return the number of elements on the x-axis of the block
designated by \p interface.

\def STARPU_BLOCK_GET_NY(void *interface)
\ingroup Data_Interfaces
Return the number of elements on the y-axis of the block
designated by \p interface.

\def STARPU_BLOCK_GET_NZ(void *interface)
\ingroup Data_Interfaces
Return the number of elements on the z-axis of the block
designated by \p interface.

\def STARPU_BLOCK_GET_LDY(void *interface)
\ingroup Data_Interfaces
Return the number of elements between each row of the block
designated by \p interface. May be equal to nx when there is no padding.

\def STARPU_BLOCK_GET_LDZ(void *interface)
\ingroup Data_Interfaces
Return the number of elements between each z plane of the block
designated by \p interface. May be equal to nx*ny when there is no
padding.

\def STARPU_BLOCK_GET_ELEMSIZE(void *interface)
\ingroup Data_Interfaces
Return the size of the elements of the block designated by
\p interface.

@name Accessing BCSR Data Interfaces
\ingroup Data_Interfaces

\struct starpu_bcsr_interface
\brief BCSR interface for sparse matrices (blocked compressed sparse
row representation)
\ingroup Data_Interfaces
\var starpu_bcsr_interface::id
Identifier of the interface
\var starpu_bcsr_interface::nnz
number of non-zero BLOCKS
\var starpu_bcsr_interface::nrow
number of rows (in terms of BLOCKS)
\var starpu_bcsr_interface::nzval
non-zero values
\var starpu_bcsr_interface::colind
position of non-zero entried on the row
\var starpu_bcsr_interface::rowptr
index (in nzval) of the first entry of the row
\var starpu_bcsr_interface::firstentry
k for k-based indexing (0 or 1 usually). Also useful when partitionning the matrix.
\var starpu_bcsr_interface::r
size of the blocks
\var starpu_bcsr_interface::c
size of the blocks
\var starpu_bcsr_interface::elemsize;
size of the elements of the matrix

\fn uint32_t starpu_bcsr_get_nnz(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of non-zero elements in the matrix designated
by \p handle.

\fn uint32_t starpu_bcsr_get_nrow(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of rows (in terms of blocks of size r*c) in
the matrix designated by \p handle.

\fn uint32_t starpu_bcsr_get_firstentry(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the index at which all arrays (the column indexes, the
row pointers...) of the matrix desginated by \p handle.

\fn uintptr_t starpu_bcsr_get_local_nzval(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a pointer to the non-zero values of the matrix
designated by \p handle.

\fn uint32_t * starpu_bcsr_get_local_colind(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a pointer to the column index, which holds the positions
of the non-zero entries in the matrix designated by \p handle.

\fn uint32_t * starpu_bcsr_get_local_rowptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the row pointer array of the matrix designated by
\p handle.

\fn uint32_t starpu_bcsr_get_r(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of rows in a block.

\fn uint32_t starpu_bcsr_get_c(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the numberof columns in a block.

\fn size_t starpu_bcsr_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the elements in the matrix designated by
\p handle.

\def STARPU_BCSR_GET_NNZ(void *interface)
\ingroup Data_Interfaces
Return the number of non-zero values in the matrix designated
by \p interface.

\def STARPU_BCSR_GET_NZVAL(void *interface)
\ingroup Data_Interfaces
Return a pointer to the non-zero values of the matrix
designated by \p interface.

\def STARPU_BCSR_GET_NZVAL_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the array of non-zero values in the
matrix designated by \p interface. The offset documented below has to be
used in addition to this.

\def STARPU_BCSR_GET_COLIND(void *interface)
\ingroup Data_Interfaces
Return a pointer to the column index of the matrix designated
by \p interface.

\def STARPU_BCSR_GET_COLIND_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the column index of the matrix
designated by \p interface. The offset documented below has to be used in
addition to this.

\def STARPU_BCSR_GET_ROWPTR(void *interface)
\ingroup Data_Interfaces
Return a pointer to the row pointer array of the matrix
designated by \p interface.

\def STARPU_CSR_GET_ROWPTR_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the row pointer array of the matrix
designated by \p interface. The offset documented below has to be used in
addition to this.

\def STARPU_BCSR_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the arrays (coling, rowptr, nzval) of the
matrix designated by \p interface, to be used with the device handles.

@name Accessing CSR Data Interfaces
\ingroup Data_Interfaces

\struct starpu_csr_interface
\brief CSR interface for sparse matrices (compressed sparse row representation)
\ingroup Data_Interfaces
\var starpu_csr_interface::id
Identifier of the interface
\var starpu_csr_interface::nnz
number of non-zero entries
\var starpu_csr_interface::nrow
number of rows
\var starpu_csr_interface::nzval
non-zero values
\var starpu_csr_interface::colind
position of non-zero entries on the row
\var starpu_csr_interface::rowptr
index (in nzval) of the first entry of the row
\var starpu_csr_interface::firstentry
k for k-based indexing (0 or 1 usually). also useful when partitionning the matrix.
\var starpu_csr_interface::elemsize
size of the elements of the matrix

\fn uint32_t starpu_csr_get_nnz(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the number of non-zero values in the matrix designated
by \p handle.

\fn uint32_t starpu_csr_get_nrow(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the row pointer array of the matrix
designated by \p handle.

\fn uint32_t starpu_csr_get_firstentry(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the index at which all arrays (the column indexes, the
row pointers...) of the matrix designated by \p handle.

\fn uintptr_t starpu_csr_get_local_nzval(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a local pointer to the non-zero values of the matrix
designated by \p handle.

\fn uint32_t * starpu_csr_get_local_colind(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a local pointer to the column index of the matrix
designated by \p handle.

\fn uint32_t * starpu_csr_get_local_rowptr(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return a local pointer to the row pointer array of the matrix
designated by \p handle.

\fn size_t starpu_csr_get_elemsize(starpu_data_handle_t handle)
\ingroup Data_Interfaces
Return the size of the elements registered into the matrix
designated by \p handle.

\def STARPU_CSR_GET_NNZ(void *interface)
\ingroup Data_Interfaces
Return the number of non-zero values in the matrix designated
by \p interface.

\def STARPU_CSR_GET_NROW(void *interface)
\ingroup Data_Interfaces
Return the size of the row pointer array of the matrix
designated by \p interface.

\def STARPU_CSR_GET_NZVAL(void *interface)
\ingroup Data_Interfaces
Return a pointer to the non-zero values of the matrix
designated by \p interface.

\def STARPU_CSR_GET_NZVAL_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the array of non-zero values in the
matrix designated by \p interface. The offset documented below has to be
used in addition to this.

\def STARPU_CSR_GET_COLIND(void *interface)
\ingroup Data_Interfaces
Return a pointer to the column index of the matrix designated
by \p interface.

\def STARPU_CSR_GET_COLIND_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the column index of the matrix
designated by \p interface. The offset documented below has to be used in
addition to this.

\def STARPU_CSR_GET_ROWPTR(void *interface)
\ingroup Data_Interfaces
Return a pointer to the row pointer array of the matrix
designated by \p interface.

\def STARPU_CSR_GET_ROWPTR_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the row pointer array of the matrix
designated by \p interface. The offset documented below has to be used in
addition to this.

\def STARPU_CSR_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the arrays (colind, rowptr, nzval) of the
matrix designated by \p interface, to be used with the device handles.

\def STARPU_CSR_GET_FIRSTENTRY(void *interface)
\ingroup Data_Interfaces
Return the index at which all arrays (the column indexes, the
row pointers...) of the \p interface start.

\def STARPU_CSR_GET_ELEMSIZE(void *interface)
\ingroup Data_Interfaces
Return the size of the elements registered into the matrix
designated by \p interface.

@name Accessing COO Data Interfaces
\ingroup Data_Interfaces

\struct starpu_coo_interface
\brief COO Matrices
\ingroup Data_Interfaces
\var starpu_coo_interface::id
identifier of the interface
\var starpu_coo_interface::columns
column array of the matrix
\var starpu_coo_interface::rows
row array of the matrix
\var starpu_coo_interface::values
values of the matrix
\var starpu_coo_interface::nx
number of elements on the x-axis of the matrix
\var starpu_coo_interface::ny
number of elements on the y-axis of the matrix
\var starpu_coo_interface::n_values
number of values registered in the matrix
\var starpu_coo_interface::elemsize
size of the elements of the matrix

\def STARPU_COO_GET_COLUMNS(void *interface)
\ingroup Data_Interfaces
Return a pointer to the column array of the matrix designated
by \p interface.

\def STARPU_COO_GET_COLUMNS_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the column array of the matrix
designated by \p interface, to be used on OpenCL. The offset documented
below has to be used in addition to this.

\def STARPU_COO_GET_ROWS(interface)
\ingroup Data_Interfaces
Return a pointer to the rows array of the matrix designated by
\p interface.

\def STARPU_COO_GET_ROWS_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the row array of the matrix
designated by \p interface, to be used on OpenCL. The offset documented
below has to be used in addition to this.

\def STARPU_COO_GET_VALUES(interface)
\ingroup Data_Interfaces
Return a pointer to the values array of the matrix designated
by \p interface.

\def STARPU_COO_GET_VALUES_DEV_HANDLE(void *interface)
\ingroup Data_Interfaces
Return a device handle for the value array of the matrix
designated by \p interface, to be used on OpenCL. The offset documented
below has to be used in addition to this.

\def STARPU_COO_GET_OFFSET(void *interface)
\ingroup Data_Interfaces
Return the offset in the arrays of the COO matrix designated by
\p interface.

\def STARPU_COO_GET_NX(interface)
\ingroup Data_Interfaces
Return the number of elements on the x-axis of the matrix
designated by \p interface.

\def STARPU_COO_GET_NY(interface)
\ingroup Data_Interfaces
Return the number of elements on the y-axis of the matrix
designated by \p interface.

\def STARPU_COO_GET_NVALUES(interface)
\ingroup Data_Interfaces
Return the number of values registered in the matrix designated
by \p interface.

\def STARPU_COO_GET_ELEMSIZE(interface)
\ingroup Data_Interfaces
Return the size of the elements registered into the matrix
designated by \p interface.

@name Defining Interface
\ingroup Data_Interfaces

Applications can provide their own interface as shown in \ref
Defining_a_New_Data_Interface.

\fn uintptr_t starpu_malloc_on_node(unsigned dst_node, size_t size)
\ingroup Data_Interfaces
Allocate \p size bytes on node \p dst_node. This returns 0 if
allocation failed, the allocation method should then return <c>-ENOMEM</c> as
allocated size.

\fn void starpu_free_on_node(unsigned dst_node, uintptr_t addr, size_t size)
\ingroup Data_Interfaces
Free \p addr of \p size bytes on node \p dst_node.

\fn int starpu_interface_copy(uintptr_t src, size_t src_offset, unsigned src_node, uintptr_t dst, size_t dst_offset, unsigned dst_node, size_t size, void *async_data)
\ingroup Data_Interfaces
Copy \p size bytes from byte offset \p src_offset of \p src on \p src_node
to byte offset \p dst_offset of \p dst on \p dst_node. This is to be used in
the any_to_any() copy method, which is provided with the async_data to
be passed to starpu_interface_copy(). this returns <c>-EAGAIN</c> if the
transfer is still ongoing, or 0 if the transfer is already completed.

\fn uint32_t starpu_hash_crc32c_be_n(const void *input, size_t n, uint32_t inputcrc)
\ingroup Data_Interfaces
Compute the CRC of a byte buffer seeded by the \p inputcrc
<em>current state</em>. The return value should be considered as the new
<em>current state</em> for future CRC computation. This is used for computing
data size footprint.

\fn uint32_t starpu_hash_crc32c_be(uint32_t input, uint32_t inputcrc)
\ingroup Data_Interfaces
Compute the CRC of a 32bit number seeded by the \p inputcrc
<em>current state</em>. The return value should be considered as the new
<em>current state</em> for future CRC computation. This is used for computing
data size footprint.

\fn uint32_t starpu_hash_crc32c_string(const char *str, uint32_t inputcrc)
\ingroup Data_Interfaces
Compute the CRC of a string seeded by the \p inputcrc <em>current
state</em>. The return value should be considered as the new <em>current
state</em> for future CRC computation. This is used for computing data
size footprint.

\fn int starpu_data_interface_get_next_id(void)
\ingroup Data_Interfaces
Return the next available id for a newly created data interface
(\ref Defining_a_New_Data_Interface).

*/