We define basic shared memory routines. More...

#include <t8.h>
#include <sc_shmem.h>

Macros
#define	T8_SHMEM_BEST_TYPE SC_SHMEM_BASIC
	Defines the shared memory type that is best suited for t8code and the current machine. More...

Typedefs
typedef struct t8_shmem_array *	t8_shmem_array_t

Functions
void	t8_shmem_init (sc_MPI_Comm comm)
	Initialize shared memory usage for a communicator. More...

void	t8_shmem_finalize (sc_MPI_Comm comm)
	Finalize shared memory usage for a communicator. More...

void	t8_shmem_set_type (sc_MPI_Comm comm, sc_shmem_type_t type)
	Set a shared memory type of a communicator. More...

void	t8_shmem_array_init (t8_shmem_array_t *parray, size_t elem_size, size_t elem_count, sc_MPI_Comm comm)
	Initialize and allocate a shared memory array structure. More...

int	t8_shmem_array_start_writing (t8_shmem_array_t array)
	Enable writing mode for a shmem array. More...

void	t8_shmem_array_end_writing (t8_shmem_array_t array)
	Disable writing mode for a shmem array. More...

void	t8_shmem_array_set_gloidx (t8_shmem_array_t array, int index, t8_gloidx_t value)
	Set an entry of a t8_shmem array that is used to store t8_gloidx_t. More...

void	t8_shmem_array_copy (t8_shmem_array_t dest, t8_shmem_array_t source)
	Copy the contents of one t8_shmem array into another. More...

void	t8_shmem_array_allgather (const void *sendbuf, int sendcount, sc_MPI_Datatype sendtype, t8_shmem_array_t recvarray, int recvcount, sc_MPI_Datatype recvtype)
	Fill a t8_shmem array with an allgather. More...

sc_MPI_Comm	t8_shmem_array_get_comm (t8_shmem_array_t array)
	Return the MPI communicator associated with a shmem array. More...

size_t	t8_shmem_array_get_elem_size (t8_shmem_array_t array)
	Get the element size of a t8_shmem_array. More...

size_t	t8_shmem_array_get_elem_count (t8_shmem_array_t array)
	Get the number of elements of a t8_shmem_array. More...

const t8_gloidx_t *	t8_shmem_array_get_gloidx_array (t8_shmem_array_t array)
	Return a read-only pointer to the data of a shared memory array interpreted as an t8_gloidx_t array. More...

t8_gloidx_t *	t8_shmem_array_get_gloidx_array_for_writing (t8_shmem_array_t array)
	Return a pointer to the data of a shared memory array interpreted as an t8_gloidx_t array. More...

t8_gloidx_t	t8_shmem_array_get_gloidx (t8_shmem_array_t array, int index)
	Return an entry of a shared memory array that stores t8_gloidx_t. More...

const void *	t8_shmem_array_get_array (t8_shmem_array_t array)
	Return a pointer to the data array of a t8_shmem_array. More...

const void *	t8_shmem_array_index (t8_shmem_array_t array, size_t index)
	Return a read-only pointer to an element in a t8_shmem_array. More...

void *	t8_shmem_array_index_for_writing (t8_shmem_array_t array, size_t index)
	Return a pointer to an element in a t8_shmem_array in writing mode. More...

int	t8_shmem_array_is_equal (t8_shmem_array_t array_a, t8_shmem_array_t array_b)

void	t8_shmem_array_destroy (t8_shmem_array_t *parray)
	Free all memory associated with a t8_shmem_array. More...

Detailed Description

We define basic shared memory routines.

Macro Definition Documentation

◆ T8_SHMEM_BEST_TYPE

#define T8_SHMEM_BEST_TYPE SC_SHMEM_BASIC

Defines the shared memory type that is best suited for t8code and the current machine.

See also: sc_shmem.h

Function Documentation

◆ t8_shmem_array_allgather()

void t8_shmem_array_allgather	(	const void *	sendbuf,
		int	sendcount,
		sc_MPI_Datatype	sendtype,
		t8_shmem_array_t	recvarray,
		int	recvcount,
		sc_MPI_Datatype	recvtype
	)

Fill a t8_shmem array with an allgather.

Parameters

[in]	sendbuf	the source from this process
[in]	sendcount	the number of items to allgather
[in]	sendtype	the type of items to allgather
[in,out]	recvbuf	the destination shmem array
[in]	recvcount	the number of items to allgather
[in]	recvtype	the type of items to allgather

Note: Writing mode must be disabled for recvarray.

◆ t8_shmem_array_copy()

void t8_shmem_array_copy	(	t8_shmem_array_t	dest,
		t8_shmem_array_t	source
	)

Copy the contents of one t8_shmem array into another.

Parameters

[in,out]	dest	The array in which source should be copied.
[in]	source	The array to copy.

Note: dest must be initialized and match in element size and element count to source.; dest must have writing mode disabled.

◆ t8_shmem_array_destroy()

void t8_shmem_array_destroy ( t8_shmem_array_t * parray )

Free all memory associated with a t8_shmem_array.

Parameters

[in,out] parray On input a pointer to a valid t8_shmem_array. This array is freed and parray is set to NULL on return.

◆ t8_shmem_array_end_writing()

void t8_shmem_array_end_writing ( t8_shmem_array_t array )

Disable writing mode for a shmem array.

Parameters

[in,out] array Initialized with writing mode enabled.

See also: t8_shmem_array_start_writing.

Note: This function is MPI collective.

◆ t8_shmem_array_get_array()

const void* t8_shmem_array_get_array ( t8_shmem_array_t array )

Return a pointer to the data array of a t8_shmem_array.

Parameters

[in] array The t8_shmem_array.

Returns: A pointer to the data array of array.

Note: Writing mode must be disabled for array.

◆ t8_shmem_array_get_comm()

sc_MPI_Comm t8_shmem_array_get_comm ( t8_shmem_array_t array )

Return the MPI communicator associated with a shmem array.

Parameters

[in] array The shmem_array to be queried.

Returns: The MPI communicator stored at array.

◆ t8_shmem_array_get_elem_count()

size_t t8_shmem_array_get_elem_count ( t8_shmem_array_t array )

Get the number of elements of a t8_shmem_array.

Parameters

[in] array The array.

Returns: The number of elements in array.

◆ t8_shmem_array_get_elem_size()

size_t t8_shmem_array_get_elem_size ( t8_shmem_array_t array )

Get the element size of a t8_shmem_array.

Parameters

[in] array The array.

Returns: The element size of array's elements.

◆ t8_shmem_array_get_gloidx()

t8_gloidx_t t8_shmem_array_get_gloidx	(	t8_shmem_array_t	array,
		int	index
	)

Return an entry of a shared memory array that stores t8_gloidx_t.

Parameters

[in]	array	The t8_shmem_array
[in]	index	The index of the entry to be queried.

Returns: The index-th entry of array as t8_gloidx_t.

Note: Writing mode must be disabled for array.

◆ t8_shmem_array_get_gloidx_array()

const t8_gloidx_t* t8_shmem_array_get_gloidx_array ( t8_shmem_array_t array )

Return a read-only pointer to the data of a shared memory array interpreted as an t8_gloidx_t array.

Parameters

[in] array The t8_shmem_array

Returns: The data of array as t8_gloidx_t pointer.

Note: Writing mode must be disabled for array.

◆ t8_shmem_array_get_gloidx_array_for_writing()

t8_gloidx_t* t8_shmem_array_get_gloidx_array_for_writing ( t8_shmem_array_t array )

Return a pointer to the data of a shared memory array interpreted as an t8_gloidx_t array.

The array must have writing enabled t8_shmem_array_start_writing and you should not write into the memory after t8_shmem_array_end_writing was called.

Parameters

[in] array The t8_shmem_array

Returns: The data of array as t8_gloidx_t pointer.

◆ t8_shmem_array_index()

const void* t8_shmem_array_index	(	t8_shmem_array_t	array,
		size_t	index
	)

Return a read-only pointer to an element in a t8_shmem_array.

Parameters

[in]	array	The t8_shmem_array.
[in]	index	The index of an element.

Returns: A pointer to the element at index in array.

Note: You should not modify the value.; Writing mode must be disabled for array.

◆ t8_shmem_array_index_for_writing()

void* t8_shmem_array_index_for_writing	(	t8_shmem_array_t	array,
		size_t	index
	)

Return a pointer to an element in a t8_shmem_array in writing mode.

Parameters

[in]	array	The t8_shmem_array.
[in]	index	The index of an element.

Returns: A pointer to the element at index in array.

Note: You can modify the value before the next call to t8_shmem_array_end_writing.; Writing mode must be enabled for array.

◆ t8_shmem_array_init()

void t8_shmem_array_init	(	t8_shmem_array_t *	parray,
		size_t	elem_size,
		size_t	elem_count,
		sc_MPI_Comm	comm
	)

Initialize and allocate a shared memory array structure.

Parameters

[in,out]	parray	On input this pointer must be non-NULL. On return this pointer is set to the new t8_shmem_array.
[in]	elem_size	The size in bytes of an array element.
[in]	elem_count	The total number of elements to allocate.
[in]	comm	The MPI communicator to be associated with the shmem_array. If not set, the shared memory type will be set to T8_SHMEM_BEST_TYPE.

◆ t8_shmem_array_set_gloidx()

void t8_shmem_array_set_gloidx	(	t8_shmem_array_t	array,
		int	index,
		t8_gloidx_t	value
	)

Set an entry of a t8_shmem array that is used to store t8_gloidx_t.

The array must have writing mode enabled t8_shmem_array_start_writing.

Parameters

[in,out]	array	The array to be mofified.
[in]	index	The array entry to be modified.
[in]	value	The new value to be set.

◆ t8_shmem_array_start_writing()

int t8_shmem_array_start_writing ( t8_shmem_array_t array )

Enable writing mode for a shmem array.

Only some processes may be allowed to write into the array, which is indicated by the return value being non-zero.

Parameters

[in,out] array Initialized array. Writing will be enabled on certain processes.

Returns: True if the calling process can write into the array.

Note: This function is MPI collective.

◆ t8_shmem_finalize()

void t8_shmem_finalize ( sc_MPI_Comm comm )

Finalize shared memory usage for a communicator.

This destroys the intra- and internode communicators.

Parameters

[in] comm The MPI Communicator.

Note: Call this function if you initialized the communicator for shared memory usage and you are sure that you will not use it for shared memory again.; Calling this function multiple times with the same communicator is safe and does not change the behaviour.

◆ t8_shmem_init()

void t8_shmem_init ( sc_MPI_Comm comm )

Initialize shared memory usage for a communicator.

This sets up the intra- and internode communicators.

Parameters

[in] comm The MPI Communicator.

Note: This function needs to be called to enable shared memory usage for a communicator.; Calling this function multiple times with the same communicator is safe and does not change the behaviour.

◆ t8_shmem_set_type()

void t8_shmem_set_type	(	sc_MPI_Comm	comm,
		sc_shmem_type_t	type
	)

Set a shared memory type of a communicator.

If the type was already set it is overwritten.

Parameters

[in,out]	comm	The MPI Communicator
[in]	type	A shared memory type.

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ T8_SHMEM_BEST_TYPE

Function Documentation

◆ t8_shmem_array_allgather()

◆ t8_shmem_array_copy()

◆ t8_shmem_array_destroy()

◆ t8_shmem_array_end_writing()

◆ t8_shmem_array_get_array()

◆ t8_shmem_array_get_comm()

◆ t8_shmem_array_get_elem_count()

◆ t8_shmem_array_get_elem_size()

◆ t8_shmem_array_get_gloidx()

◆ t8_shmem_array_get_gloidx_array()

◆ t8_shmem_array_get_gloidx_array_for_writing()

◆ t8_shmem_array_index()

◆ t8_shmem_array_index_for_writing()

◆ t8_shmem_array_init()

◆ t8_shmem_array_set_gloidx()

◆ t8_shmem_array_start_writing()

◆ t8_shmem_finalize()

◆ t8_shmem_init()

◆ t8_shmem_set_type()