main.c File Reference

PLUTO main function. More...

#include "pluto.h"
#include "globals.h"

Functions
static double	GetNextTimeStep (Time_Step *, struct INPUT *, Grid *)
static int	Integrate (Data *, Riemann_Solver *, Time_Step *, Grid *)
static void	CheckForOutput (Data *, Input *, Grid *)
int	main (int argc, char *argv[])

Detailed Description

The file main.c contains the PLUTO main function and several other top-level routines. main() provides basic code initialization, handles the the principal integration loop and calls the output driver write_data.c. Other useful functions contained in this file are Integrate() which does the actual integration, GetNextTimeStep() responsible for computing the next time step based on the information available at the last time level.

We use two slightly different integration loops depending on whether asnchrounous I/O has to be performed (macro USE_ASYNC_IO). If the macro USE_ASYNC_IO is not defined, the standard integration loop consists of the following steps:

• Check for last step & adjust dt if necessary
• Dump log information, n, t(n), dt(n), MAX_MACH(n-1), etc..
• Check output/analysis: t(n) < tout < t(n)+dt(n)
• write to disk/call analysis using {U(n), t(n), dt(n)}
• Advance solution using dt(n): U(n) –> U(n+1)
• Increment t(n+1) = t(n) + dt(n)
• [MPI] Show dominant time step (n)
• [MPI] Get next time step dt(n+1)
• [MPI] reduction operations (n)
• Increment n –> n+1

Otherwise, using Asynchrounous I/O:

• Check for last step & adjust dt
• check for output/analysis: t(n) < tout < t(n+1)
  • Write data/call analysis using {U(n), t(n), dt(n)}
• [MPI] Show dominant time step (n-1)
• [MPI] reduction operations (n-1)
• [AIO]: finish writing
• Dump log information, n, t(n), dt(n), MAX_MACH(n-1), etc..
• Advance solution using dt(n), U(n) –> U(n+1)
• Increment t(n+1) = t(n) + dt(n)
• [MPI] Get next time step dt(n)
• Increment n –> n+1

Author

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)

Date

Aug 16, 2012

Function Documentation

void CheckForOutput ( Data *  d, Input *  ini, Grid *  grid  )

static

Check if file output has to be performed.

double GetNextTimeStep ( Time_Step *  Dts, struct INPUT *  ini, Grid *  grid  )

static

Compute and return the time step for the next time level using the information from the previous integration (Dts->inv_dta and Dts->inv_dp).

Parameters

[in]	Dts	pointer to the Time_Step structure
[in]	ini	pointer to the Input structure
[in]	grid	pointer to array of Grid structures

Returns

The time step for next time level

int Integrate ( Data *  d, Riemann_Solver *  Solver, Time_Step *  Dts, Grid *  grid  )

static

Advance equations by a single time-step.

Parameters

d	pointer to PLUTO Data structure;
Solver	pointer to a Riemann solver function;
Dts	pointer to time Step structure;
grid	pointer to grid structure.

Returns

An integer giving success / failure (development).

int main	(	int	argc,
		char *	argv[]
	)

Start PLUTO, initialize functions, define data structures and handle the main integration loop.

Parameters

[in]	argc	Argument counts.
[in]	argv	Array of pointers to the strings.

Returns

This function return 0 on normal exit.