Init Class Reference

Starts and owns the libraries DiFfRG runs on: MPI, PETSc, SLEPc, Zoltan, p4est and Kokkos. More...

#include <init.hh>

Public Member Functions
	Init (int argc, char *argv[], const std::string parameter_file="parameter.json")
	Start the libraries (first call only) and remember the command line.
	Init (const std::string parameter_file="parameter.json")
	Start the libraries without a command line.
const ConfigurationHelper	get_configuration_helper () const
	Parse the stored command line and parameter file.

Static Public Member Functions
static bool	is_initialized ()
	Whether an Init has already started the libraries.

Detailed Description

Starts and owns the libraries DiFfRG runs on: MPI, PETSc, SLEPc, Zoltan, p4est and Kokkos.

The first Init of a process does all the work; later ones only store their arguments. The libraries stay up until the process exits, and are shut down by exit handlers, not by ~Init: the Init object may be a temporary. Do not initialize MPI or Kokkos yourself.

The first construction

• reads the parameter file and command line silently (ConfigurationHelper::probe()) for the keys below,
• sets the CPU thread budget, see ThreadSource,
• starts MPI and the other libraries,
• with several MPI ranks on one node, assigns GPUs round robin: node-local rank \(r\) gets device \(r \bmod n_\text{GPU}\), and warns if two ranks end up on the same GPU,
• starts Kokkos.

Keys read here (all optional):

• /discretization/threads (uint, default 0 = automatic): CPU threads per rank.
• /integration/map_quantum (double, default 0 = automatic): work-split size of the integrator map scheduler, see MapScheduler::set_quantum().
• /integration/map_verbose (bool, default false): log every map schedule.

Constructor & Destructor Documentation

Init() [1/2]

Init	(	int	argc,
		char *	argv[],
		const std::string	parameter_file = "parameter.json" )

Start the libraries (first call only) and remember the command line.

Parameters

argc	Forwarded argc from main().
argv	Forwarded argv from main().
parameter_file	The default parameter file; must be the same file the application reads.

Init() [2/2]

Init

(

const std::string

parameter_file = "parameter.json"

)

Start the libraries without a command line.

Parameters

parameter_file

The default parameter file.

Member Function Documentation

get_configuration_helper()

const ConfigurationHelper get_configuration_helper

(

)

const

Parse the stored command line and parameter file.

Builds a new ConfigurationHelper on every call, with all its effects (e.g. --help exits).

is_initialized()

static bool is_initialized ( )

static

Whether an Init has already started the libraries.

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

• /home/runner/work/DiFfRG/DiFfRG/DiFfRG/include/DiFfRG/common/init.hh