HaloExchange Class Reference

Point-to-point exchange of per-cell state following a Distribution's plan. Buffers are packed on the device; they go to MPI directly when host-accessible or with Mallard_GPU_AWARE_MPI, else through host copies. More...

#include <halo_exchange.h>

Public Member Functions
	HaloExchange ()=default
	HaloExchange (const Distribution &dist, bool nccl)
	With nccl, messages are NCCL operations on the default execution space's stream.
void	exchange (const State &U)
	Overwrite the halo cells of U with the owners' values (collective among neighbors).
void	start (const State &U)
	Send the owned values of U that neighbors need and post the receives; the halo cells of U stay stale until finish(). With NCCL nothing blocks the host: the messages are ordered after the work enqueued so far on the default execution space.
void	finish (const State &U)
	Wait for the messages of start() and fill the halo cells of U (with NCCL: enqueue the filling after the messages).
bool	active () const
bool	uses_nccl () const

Detailed Description

Point-to-point exchange of per-cell state following a Distribution's plan. Buffers are packed on the device; they go to MPI directly when host-accessible or with Mallard_GPU_AWARE_MPI, else through host copies.

Constructor & Destructor Documentation

HaloExchange() [1/2]

HaloExchange::HaloExchange ( )

default

HaloExchange() [2/2]

HaloExchange::HaloExchange	(	const Distribution &	dist,
		bool	nccl
	)

With nccl, messages are NCCL operations on the default execution space's stream.

Member Function Documentation

active()

bool HaloExchange::active ( ) const

inline

exchange()

void HaloExchange::exchange ( const State &  U )

inline

Overwrite the halo cells of U with the owners' values (collective among neighbors).

finish()

void HaloExchange::finish

(

const State &

U

)

Wait for the messages of start() and fill the halo cells of U (with NCCL: enqueue the filling after the messages).

start()

void HaloExchange::start

(

const State &

U

)

Send the owned values of U that neighbors need and post the receives; the halo cells of U stay stale until finish(). With NCCL nothing blocks the host: the messages are ordered after the work enqueued so far on the default execution space.

uses_nccl()

bool HaloExchange::uses_nccl ( ) const

inline

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The documentation for this class was generated from the following files:

• /home/runner/work/mallard/mallard/mallard/src/parallel/halo_exchange.h
• /home/runner/work/mallard/mallard/mallard/src/parallel/halo_exchange.cpp