Logfile Unit

Flash-X supplies the Logfile unit to manage an output log during a Flash-X simulation. The logfile contains various types of useful information, warnings, and error messages produced by a Flash-X run. Other units can add information to the logfile through the Logfile unit interface. The Logfile routines enable a program to open and close a log file, write time or date stamps to the file, and write arbitrary messages to the file. The file is kept closed and is only opened for appending when information is to be written, thus avoiding problems with unflushed buffers. For this reason, Logfile routines should not be called within time-sensitive loops, as system calls are generated. Even when starting from scratch, the logfile is opened in append mode to avoid deleting important logfiles. Two kinds of Logfiles are supported. The first kind is similar to that in |flashx|2 and early releases of |flashx|, where the master processor has exclusive access to the logfile and writes global information to it. The newer kind gives all processors access to their own private logfiles if they need to have one. Similar to the traditional logfile, the private logfiles are opened in append mode, and they are created the first time a processor writes to one. The private logfiles are extremely useful to gather information about failures causes by a small fraction of processors; something that cannot be done in the traditional logfile.

The Logfile unit is included by default in all the provided Flash-X simulations because it is required by the Driver/DriverMain Config. As with all the other units in Flash-X, the data specific to the Logfile unit is stored in the module Logfile_data.F90. Logfile unit scope data variables begin with the prefix log_variableName and they are initialized in the routine monitors/Logfile/Logfile_init.

By default, the logfile is named flash.log and found in the output directory. The user may change the name of the logfile by altering the runtime parameter Logfile/log_file in the flash.par.

# names of files basenm = “cellular_” log_file = “cellular.log”

Meta Data

The logfile stores meta data about a given run including the time and date of the run, the number of MPI tasks, dimensionality, compiler flags and other information about the run. The snippet below is an example from a logfile showing the basic setup and compilation information:

Runtime Parameters, Physical Constants, and Multispecies Data

The logfile also records which units were included in a simulation, the runtime parameters, physical constants, and any species and their properties from the Multispecies unit. The Flash-X logfile keeps track of whether a runtime parameter is a default value or whether its value has been redefined in the flash.par The [CHANGED] symbol will occur next to a runtime parameter if its value has been redefined in the flash.par. Note that the runtime parameters are output in alphabetical order within the Fortran datatype – so integer parameters are shown first, then real, then string, then Boolean. The snippet below shows the this portion of the logfile; omitted sections are indicated with “…”.

Flash-X Units used: Driver Driver/DriverMain Driver/DriverMain/TimeDep Grid Grid/GridMain Grid/GridMain/paramesh Grid/GridMain/paramesh/paramesh4 … Multispecies Particles PhysicalConstants PhysicalConstants/PhysicalConstantsMain RuntimeParameters RuntimeParameters/RuntimeParametersMain … physics/utilities/solvers/LinearAlgebra ============================================================================== RuntimeParameters:

algebra = 2 [CHANGED] bndpriorityone = 1 bndprioritythree = 3 … cfl = 0.800E+00 checkpointfileintervaltime = 0.100E-08 [CHANGED] cvisc = 0.100E+00 derefine_cutoff_1 = 0.200E+00 derefine_cutoff_2 = 0.200E+00 … zmax = 0.128E+02 [CHANGED] zmin = 0.000E+00 basenm = cellular_ [CHANGED] eosmode = dens_ie eosmodeinit = dens_ie geometry = cartesian log_file = cellular.log [CHANGED] output_directory = pc_unitsbase = CGS plot_grid_var_1 = none plot_grid_var_10 = none plot_grid_var_11 = none plot_grid_var_12 = none plot_grid_var_2 = none … yr_boundary_type = periodic zl_boundary_type = periodic zr_boundary_type = periodic bytepack = F chkguardcells = F converttoconsvdformeshcalls = F converttoconsvdinmeshinterp = F … useburn = T [CHANGED] useburntable = F

Known units of measurement:

Unit CGS Value Base Unit 1 cm 1.0000 cm 2 s 1.0000 s 3 K 1.0000 K 4 g 1.0000 g 5 esu 1.0000 esu 6 m 100.00 cm 7 km 0.10000E+06 cm 8 pc 0.30857E+19 cm … Known physical constants:

Constant Name Constant Value cm s g K esu 1 Newton 0.66726E-07 3.00 -2.00 -1.00 0.00 0.00 2 speed of light 0.29979E+11 1.00 -1.00 0.00 0.00 0.00 … 15 Euler 0.57722 0.00 0.00 0.00 0.00 0.00 ==============================================================================

Multifluid database contents:

Initially defined values of species: Name Index Total Positive Neutral Negative bind Ener Gamma ar36 12 3.60E+01 1.80E+01 -9.99E+02 -9.99E+02 3.07E+02 -9.99E+02 c12 13 1.20E+01 6.00E+00 -9.99E+02 -9.99E+02 9.22E+01 -9.99E+02 ca40 14 4.00E+01 2.00E+01 -9.99E+02 -9.99E+02 3.42E+02 -9.99E+02 … ti44 24 4.40E+01 2.20E+01 -9.99E+02 -9.99E+02 3.75E+02 -9.99E+02 ==============================================================================

Accessor Functions and Timestep Data

Other units within Flash-X may make calls to write information, or stamp, the logfile. For example, the Driver unit calls the API routine monitors/Logfile/Logfile_stamp after each timestep. The Grid unit calls monitors/Logfile/Logfile_stamp whenever refinement occurs in an adaptive grid simulation. If there is an error that is caught in the code the API routine Driver/Driver_abortFlash stamps the logfile before aborting the code. Any unit can stamp the logfile with one of two routines monitors/Logfile/Logfile_stamp which includes a data and time stamp along with a logfile message, or monitors/Logfile/Logfile_stampMessage which simply writes a string to the logfile.

The routine monitors/Logfile/Logfile_stamp is overloaded so the user must use the interface file Logfile_interface.F90 in the calling routine. The next snippit shows logfile output during the evolution loop of a Flash-X run.

[ 04-19-2006 16:40.43 ] [Simulation_init]: initializing Sod problem [GRID amr_refine_derefine] initiating refinement [GRID amr_refine_derefine] min blks 0 max blks 1 tot blks 1 [GRID amr_refine_derefine] min leaf blks 0 max leaf blks 1 tot leaf blks 1 [GRID amr_refine_derefine] refinement complete [ 04-19-2006 16:40.43 ] [GRID gr_expandDomain]: create level=2 … [GRID amr_refine_derefine] initiating refinement [GRID amr_refine_derefine] min blks 250 max blks 251 tot blks 501 [GRID amr_refine_derefine] min leaf blks 188 max leaf blks 188 tot leaf blks 376 [GRID amr_refine_derefine] refinement complete [ 04-19-2006 16:40.44 ] [GRID gr_expandDomain]: create level=7 [ 04-19-2006 16:40.44 ] [GRID gr_expandDomain]: create level=7 [ 04-19-2006 16:40.44 ] [GRID gr_expandDomain]: create level=7 [ 04-19-2006 16:40.44 ] [IO_writeCheckpoint] open: type=checkpoint name=sod_hdf5_chk_0000 [ 04-19-2006 16:40.44 ] [io_writeData]: wrote 501 blocks [ 04-19-2006 16:40.44 ] [IO_writeCheckpoint] close: type=checkpoint name=sod_hdf5_chk_0000 [ 04-19-2006 16:40.44 ] [IO writePlotfile] open: type=plotfile name=sod_hdf5_plt_cnt_0000 [ 04-19-2006 16:40.44 ] [io_writeData]: wrote 501 blocks [ 04-19-2006 16:40.44 ] [IO_writePlotfile] close: type=plotfile name=sod_hdf5_plt_cnt_0000 [ 04-19-2006 16:40.44 ] [Driver_evolveFlash]: Entering evolution loop [ 04-19-2006 16:40.44 ] step: n=1 t=0.000000E+00 dt=1.000000E-10 … [ 04-19-2006 16:41.06 ] [io_writeData]: wrote 501 blocks [ 04-19-2006 16:41.06 ] [IO_writePlotfile] close: type=plotfile name=sod_hdf5_plt_cnt_0002 [ 04-19-2006 16:41.06 ] [Driver_evolveFlash]: Exiting evolution loop ==============================================================================

Performance Data

Finally, the logfile records performance data for the simulation. The Timers unit (see ) is responsible for storing, collecting and interpreting the performance data. The Timers unit calls the API routine monitors/Logfile/Logfile_writeSummary to format the performance data and write it to the logfile. The snippet below shows the performance data section of a logfile.

perf_summary: code performance summary beginning : 04-19-2006 16:40.43 ending : 04-19-2006 16:41.06 seconds in monitoring period : 23.188 number of subintervals : 21 number of evolved zones : 16064 zones per second : 692.758 —————————————————————————— accounting unit time sec num calls secs avg time pct —————————————————————————— initialization 1.012 1 1.012 4.366 guardcell internal 0.155 17 0.009 0.669 writeCheckpoint 0.085 1 0.085 0.365 writePlotfile 0.061 1 0.061 0.264 evolution 22.176 1 22.176 95.633 hydro 18.214 40 0.455 78.549 guardcell internal 2.603 80 0.033 11.227 sourceTerms 0.000 40 0.000 0.002 particles 0.000 40 0.000 0.001 Grid_updateRefinement 1.238 20 0.062 5.340 tree 1.126 10 0.113 4.856 guardcell tree 0.338 10 0.034 1.459 guardcell internal 0.338 10 0.034 1.458 markRefineDerefine 0.339 10 0.034 1.460 guardcell internal 0.053 10 0.005 0.230 amr_refine_derefine 0.003 10 0.000 0.011 updateData 0.002 10 0.000 0.009 guardcell 0.337 10 0.034 1.453 guardcell internal 0.337 10 0.034 1.452 eos 0.111 10 0.011 0.481 update particle refinemen 0.000 10 0.000 0.000 io 2.668 20 0.133 11.507 writeCheckpoint 0.201 2 0.101 0.868 writePlotfile 0.079 2 0.039 0.340 diagnostics 0.040 20 0.002 0.173 ============================================================================== [ 04-19-2006 16:41.06 ] LOGFILE_END: Flash-X run complete.

Example Usage

An example program using the Logfile unit might appear as follows:

program testLogfile

use Logfile_interface, ONLY: Logfile_init, Logfile_stamp, Logfile_open, Logfile_close use Driver_interface, ONLY: Driver_initParallel use RuntimeParameters_interface, ONLY: RuntimeParameters_init use PhysicalConstants_interface, ONLY: PhysicalConstants_init

implicit none

integer :: i integer :: log_lun integer :: myPE, numProcs logical :: restart, localWrite

call Driver_initParallel(myPE, numProcs) !will initialize MPI call RuntimeParameters_init(myPE, restart) ! Logfile_init needs runtime parameters call PhysicalConstants_init(myPE) ! PhysicalConstants information adds to logfile call Logfile_init(myPE, numProcs) ! will end with Logfile_create(myPE, numProcs)

call Logfile_stamp (myPE, “beginning log file test…”, “[programtestLogfile]”) localWrite=.true. call Logfile_open(log_lun,localWrite) !! open the local logfile do i = 1, 10 write (log_lun,*) ’i = ’, i enddo call Logfile_stamp (myPE, “finished logfile test”, “[program testLogfile]”) call Logfile_close(myPE, log_lun)

end program testLogfile