Point-to-Point Communication
[Developer Documentation]

Collaboration diagram for Point-to-Point Communication:

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Detailed Description

Internals about Point-to-Point Communication.

Modules
	DMA-Helper Functions
	Functions wrapping DMA-Transfers.
	Blocking Communication
	Internals about blocking Point-to-Point Communication.
	Non-Blocking Communication
	Internals about non-blocking communication.
Internal shared functions
moc_message_envelope_t *	IMOC_get_entry (int source, int tag, MOC_Comm comm, int isSpecial, MOC_Status *status)
	Get the next valid message-envelope from "source" with specified "tag" and "comm".
int	IMOC_getFreeEntry (moc_message_envelope_t *pqueue, uint8_t tag, MOC_Comm comm, int isSpecial, int *index)
	Get next free entry in message-queue (a local copy of the message-queue has to be used).
int	IMOC_getFreeMID (int *mid)
	Get free message-ID.
int	IMOC_waitForMessageCompletion (uint8_t mid)
	Wait till message with message-ID mid has been received.
int	IMOC_testForMessageCompletion (uint8_t mid, uint8_t *status)
	Tests if message with message-ID mid has been received.
Internal constants
#define	MEMCPY_GET_TRESHOLD   156
	Defines a treshold, when to use memcpy and when to use DMA in a get-operation on the PPU.
#define	MEMCPY_PUT_TRESHOLD   2210
	Defines a treshold, when to use memcpy and when to use DMA in a put-operation on the PPU.

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Define Documentation

#define MEMCPY_GET_TRESHOLD   156

Defines a treshold, when to use memcpy and when to use DMA in a get-operation on the PPU.

Definition at line 49 of file imoc.h.

Referenced by MOC_Barrier(), MOC_Bsend(), MOC_ISsend(), and MOC_Ssend().

#define MEMCPY_PUT_TRESHOLD   2210

Defines a treshold, when to use memcpy and when to use DMA in a put-operation on the PPU.

Definition at line 55 of file imoc.h.

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Function Documentation

moc_message_envelope_t* IMOC_get_entry	(	int	source,
		int	tag,
		MOC_Comm	comm,
		int	isSpecial,
		MOC_Status *	status
	)

Get the next valid message-envelope from "source" with specified "tag" and "comm".

Parameters:

	source	in rank of sending node
	tag	in message-tag
	comm	in message-communicator
	isSpecial	in true to return special-message
	status	inout MOC_status-instance to add some information (e.g. source by MOC_ANY_SOURCE)

Returns:

pointer to the appropriate message-queue-entry.

Definition at line 13 of file imoc_get_entry.c.

References moc_message_envelope_struct::bits, moc_node_handle_ppu_struct::comm_size, moc_message_envelope_struct::communicator, moc_message_envelope_struct::flags, IMOC_LOCAL_QUEUE, moc_node_handle_ppu_struct::message_queue_base, MOC_ANY_SOURCE, MOC_ANY_TAG, MOC_Status_struct::MOC_SOURCE, node_handle, moc_node_handle_ppu_struct::queue_size, moc_node_handle_ppu_struct::rank, and moc_message_envelope_struct::tag.

Referenced by MOC_Barrier(), MOC_Iprobe(), MOC_Probe(), and MOC_Recv().

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int IMOC_getFreeEntry	(	moc_message_envelope_t *	pqueue,
		uint8_t	tag,
		MOC_Comm	comm,
		int	isSpecial,
		int *	index
	)

Get next free entry in message-queue (a local copy of the message-queue has to be used).

To ensure correct ordering message-tag and -comm and -type has to be specified.

Parameters:

	pqueue	in pointer to local copy of remote message-queue
	tag	in message-tag
	comm	in message-communicator
	isSpecial	in true if message should be a special message
	index	out index of free entry

Returns:

0 when success otherwise error-code

Definition at line 9 of file imoc_get_free_entry.c.

References moc_message_envelope_struct::bits, MOC_ERR_MESSAGE_EXHAUSTED, node_handle, and moc_node_handle_ppu_struct::queue_size.

Referenced by MOC_Barrier(), MOC_Bsend(), MOC_ISsend(), and MOC_Ssend().

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int IMOC_getFreeMID

(

int *

mid

)

Get free message-ID.

Note:

Message-ID is index of message-status-array

Parameters:

mid

out free message-ID

Return values:

	MOC_SUCCESS	No error; MPI routine completed successfully.
	MOC_ERR_MESSAGE_EXHAUSTED	No further messages possible.

Definition at line 9 of file imoc_get_free_mid.c.

References moc_message_status_struct::bits, moc_node_handle_ppu_struct::comm_size, moc_message_status_struct::flags, MOC_ERR_MESSAGE_EXHAUSTED, node_handle, moc_node_handle_ppu_struct::queue_size, and moc_node_handle_ppu_struct::status_array_base.

Referenced by MOC_Bsend(), MOC_ISsend(), and MOC_Ssend().

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int IMOC_testForMessageCompletion	(	uint8_t	mid,
		uint8_t *	status
	)

Tests if message with message-ID mid has been received.

Tests if message-status-flag 'outstanding' is 0.

Parameters:

	mid	in message-ID
	status	out status of message

Return values:

MOC_SUCCESS

No error; MPI routine completed successfully.

Definition at line 9 of file imoc_test_message.c.

References moc_message_status_struct::bits, moc_message_status_struct::flags, node_handle, and moc_node_handle_ppu_struct::status_array_base.

Referenced by MOC_Test().

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int IMOC_waitForMessageCompletion

(

uint8_t

mid

)

Wait till message with message-ID mid has been received.

Waits till message-status-flag 'outstanding' is 0.

Parameters:

mid

in message-ID

Returns:

0 when success otherwise error-code

Definition at line 9 of file imoc_wait_message.c.

References moc_message_status_struct::bits, moc_message_status_struct::flags, node_handle, and moc_node_handle_ppu_struct::status_array_base.

Referenced by MOC_Ssend(), and MOC_Wait().

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