t8_cmesh_partition.c File Reference

TODO: document this file. More...

#include <t8_data/t8_shmem.h>
#include <t8_cmesh.h>
#include <t8_element.h>
#include "t8_cmesh_types.h"
#include "t8_cmesh_trees.h"
#include "t8_cmesh_partition.h"
#include "t8_cmesh_offset.h"

Functions
void	t8_cmesh_gather_trees_per_eclass (t8_cmesh_t cmesh, sc_MPI_Comm comm)
	From num_local_trees_per_eclass compute num_trees_per_eclass. More...
void	t8_cmesh_gather_treecount (t8_cmesh_t cmesh, sc_MPI_Comm comm)
	Create the offset array for a partitioned cmesh. More...
void	t8_cmesh_gather_treecount_nocommit (t8_cmesh_t cmesh, sc_MPI_Comm comm)
	Perform the same task as t8_cmesh_gather_treecount, but do not perform the debugging check whether cmesh is committed. More...
void	t8_cmesh_partition_receive_message (t8_cmesh_t cmesh, sc_MPI_Comm comm, int proc_recv, sc_MPI_Status *status, int *local_procid, int recv_first, t8_locidx_t *num_ghosts)
void	t8_cmesh_partition (t8_cmesh_t cmesh, sc_MPI_Comm comm)
	Given a cmesh which is to be partitioned, execute the partition task. More...
void	t8_cmesh_offset_print (t8_cmesh_t cmesh, sc_MPI_Comm comm)
t8_shmem_array_t	t8_cmesh_offset_concentrate (int proc, sc_MPI_Comm comm, t8_gloidx_t num_trees)
	Create a valid partition table that concentrates all trees at a given process. More...
t8_shmem_array_t	t8_cmesh_offset_random (sc_MPI_Comm comm, t8_gloidx_t num_trees, int shared, unsigned seed)
	Create a random partition table. More...
t8_shmem_array_t	t8_cmesh_offset_percent (t8_cmesh_t cmesh, sc_MPI_Comm comm, int percent)
	Create a repartition array, where each process sends a percentage of its trees to the next process. More...
t8_shmem_array_t	t8_cmesh_offset_half (t8_cmesh_t cmesh, sc_MPI_Comm comm)
	Create a repartition array, where each process sends half of its trees to the next process. More...

Detailed Description

TODO: document this file.

Function Documentation

t8_cmesh_gather_treecount()

void t8_cmesh_gather_treecount	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm
	)

Create the offset array for a partitioned cmesh.

This function is collective.

Parameters

[in,out]	cmesh	The cmesh whose array should be created. Must be partitioned and committed.
[in]	comm	Mpi communicator used to create the offset array.

Note

if the offset array (cmesh->tree_offsets) already exists, it is not changed.

t8_cmesh_gather_treecount_nocommit()

void t8_cmesh_gather_treecount_nocommit	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm
	)

Perform the same task as t8_cmesh_gather_treecount, but do not perform the debugging check whether cmesh is committed.

Warning

Use with caution and only if you know what you are doing. Prefer t8_cmesh_gather_treecount. This function is collective.

Parameters

[in,out]	cmesh	The cmesh whose array should be created. Must be partitioned and first and last local tree as well as the total number of tree must be set.
[in]	comm	Mpi communicator used to create the offset array.

Note

if the offset array (cmesh->tree_offsets) already exists, it is not changed.

t8_cmesh_gather_trees_per_eclass()

void t8_cmesh_gather_trees_per_eclass	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm
	)

From num_local_trees_per_eclass compute num_trees_per_eclass.

This function is collective.

Parameters

[in,out]	cmesh	The cmesh whose num_trees_per_eclass values should be created. Must be partitioned and committed.
[in]	comm	Mpi communicator used to create the offset array.

Warning

This function does not perform a check whether cmesh is committed. Use with caution.

t8_cmesh_offset_concentrate()

t8_shmem_array_t t8_cmesh_offset_concentrate	(	int	proc,
		sc_MPI_Comm	comm,
		t8_gloidx_t	num_trees
	)

Create a valid partition table that concentrates all trees at a given process.

Parameters

[in]	proc	The processor that should get all trees.
[in]	comm	The communicator to use.
[in]	num_trees	The number of global trees in the partition.

Returns

A valid partition table for a cmesh with num_trees trees and communicator comm, where each tree is on process proc.

Note

This function is MPI collective.

t8_cmesh_offset_half()

t8_shmem_array_t t8_cmesh_offset_half	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm
	)

Create a repartition array, where each process sends half of its trees to the next process.

The last process does not send any trees.

Parameters

[in]	cmesh	A cmesh that is committed and partitioned.
[in]	comm	A valid MPI communicator for cmesh.

Returns

A shared memory offset array storing the new offsets. Its associated communicator is comm.

Note

This function is MPI collective.

t8_cmesh_offset_percent()

t8_shmem_array_t t8_cmesh_offset_percent	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm,
		int	percent
	)

Create a repartition array, where each process sends a percentage of its trees to the next process.

The last process does not send any trees.

Parameters

[in]	cmesh	A cmesh that is committed and partitioned.
[in]	comm	A valid MPI communicator for cmesh.
[in]	percent	The percentage of trees that this process should send to the next one. Must satisfy 0 <= percent <= 100 and be the same on each process.

Returns

A shared memory offset array storing the new offsets. Its associated communicator is comm.

Note

This function is MPI collective.

t8_cmesh_offset_random()

t8_shmem_array_t t8_cmesh_offset_random	(	sc_MPI_Comm	comm,
		t8_gloidx_t	num_trees,
		int	shared,
		unsigned	seed
	)

Create a random partition table.

The use of this function is only reasonable for debugging.

Parameters

[in]	comm	The communicator to use.
[in]	num_trees	The number of global trees in the partition.
[in]	shared	If true than there will be shared trees in the generated partition table.
[in]	seed	A seed to be used for the random number generator. If zero, a random seed is choosen. seed has to be the same on each process.

Returns

A valid partition table for a cmesh with num_trees trees and communicator comm, where each processor gets a random number of trees. The number of trees per processor is roughly uniformly distributed.

Note

This function is MPI collective.

t8_cmesh_partition()

void t8_cmesh_partition	(	t8_cmesh_t	cmesh,
		sc_MPI_Comm	comm
	)

Given a cmesh which is to be partitioned, execute the partition task.

This includes partitioning by uniform level and partitioning from a second cmesh

Parameters

[in,out]	cmesh	The cmesh to be partitioned
[in]	comm	The MPI communicator This function is usually called within t8_cmesh_commit