| 1 |
C $Header: /u/gcmpack/models/MITgcmUV/model/src/the_model_main.F,v 1.9 1998/06/01 20:36:13 adcroft Exp $ |
| 2 |
|
| 3 |
#include "CPP_EEOPTIONS.h" |
| 4 |
|
| 5 |
SUBROUTINE THE_MODEL_MAIN(myThid) |
| 6 |
C /==========================================================\ |
| 7 |
C | SUBROUTINE THE_MODEL_MAIN | |
| 8 |
C | o Master controlling routine for model using the MITgcm | |
| 9 |
C | UV parallel wrapper. | |
| 10 |
C |==========================================================| |
| 11 |
C | THE_MODEL_MAIN is invoked by the MITgcm UV parallel | |
| 12 |
C | wrapper with a single integer argument "myThid". This | |
| 13 |
C | variable identifies the thread number of an instance of | |
| 14 |
C | THE_MODEL_MAIN. Each instance of THE_MODEL_MAIN works | |
| 15 |
C | on a particular region of the models domain and | |
| 16 |
C | synchronises with other instances as necessary. The | |
| 17 |
C | routine has to "understand" the MITgcm parallel | |
| 18 |
C | environment and the numerical algorithm. Editing this | |
| 19 |
C | routine is best done with some knowledge of both aspects.| |
| 20 |
C | Notes | |
| 21 |
C | ===== | |
| 22 |
C | C*P* comments indicating place holders for which code is | |
| 23 |
C | presently being developed. | |
| 24 |
C \==========================================================/ |
| 25 |
C |
| 26 |
C Call Tree |
| 27 |
C ========= |
| 28 |
C |
| 29 |
C main ( eesupp ) |
| 30 |
C | |
| 31 |
C . |
| 32 |
C . |
| 33 |
C . Generic environment initialisation ( see eesupp/src and |
| 34 |
C . eesupp/inc ) |
| 35 |
C . multiple threads and/or processes are created in here |
| 36 |
C . |
| 37 |
C . |
| 38 |
C . |
| 39 |
C | |
| 40 |
C |-THE_MODEL_MAIN - Begin specific model. One instance |
| 41 |
C | | of this codes exists for each thread |
| 42 |
C | | and/or instance. Each instance manages |
| 43 |
C | | a specifc set of tiles. |
| 44 |
C | | |
| 45 |
C | |--INITIALISE |
| 46 |
C | | o Set initial conditions and model configuration |
| 47 |
C | | Topography, hydrography, timestep, grid, etc.. |
| 48 |
C | | |
| 49 |
C ==> | | ** Time stepping loop starts here ** |
| 50 |
C | | | |
| 51 |
C /|\ | | |
| 52 |
C | | |--LOAD_EXTERNAL_DATA |
| 53 |
C /|\ | | o Load and/or set time dependent forcing fields |
| 54 |
C | | | |
| 55 |
C /|\ | |--DYNAMICS |
| 56 |
C | | | o Evaluate "forward" terms |
| 57 |
C /|\ | | |
| 58 |
C | | |--DO_THE_MODEL_IO |
| 59 |
C /|\ | | o Write model state |
| 60 |
C | | | |
| 61 |
C /|\ | |--SOLVE_FOR_PRESSURE |
| 62 |
C | | | o Find pressure field to keep flow non-divergent |
| 63 |
C /|\ | | |
| 64 |
C | | |--DO_GTERM_BLOCKING_EXCHANGES |
| 65 |
C /|\ | | o Update overlap regions |
| 66 |
C | | | |
| 67 |
C /|\ | |--WRITE_CHECKPOINT |
| 68 |
C | | | o Write restart file(s) |
| 69 |
C /|\ | | |
| 70 |
C | | | |
| 71 |
C |<== | | ** Time stepping loop finishes here ** |
| 72 |
C | | |
| 73 |
C | |--WRITE_STATE |
| 74 |
C | |--WRITE_CHECKPOINT |
| 75 |
C | |
| 76 |
C . |
| 77 |
C . |
| 78 |
C . Generic environment termination ( see eesupp/src and |
| 79 |
C . eesupp/inc ) |
| 80 |
C . |
| 81 |
C . |
| 82 |
|
| 83 |
C == Global variables === |
| 84 |
#include "SIZE.h" |
| 85 |
#include "EEPARAMS.h" |
| 86 |
#include "PARAMS.h" |
| 87 |
#include "CG2D.h" |
| 88 |
#include "DYNVARS.h" |
| 89 |
|
| 90 |
C == Routine arguments == |
| 91 |
C myThid - Thread number for this instance of the routine. |
| 92 |
INTEGER myThid |
| 93 |
|
| 94 |
C == Local variables == |
| 95 |
C Note: Under the multi-threaded model myCurrentIter and |
| 96 |
C myCurrentTime are local variables passed around as routine |
| 97 |
C arguments. Although this is fiddly it saves the need to |
| 98 |
C impose additional synchronisation points when they are |
| 99 |
C updated. |
| 100 |
C myCurrentIter - Iteration counter for this thread |
| 101 |
C myCurrentTime - Time counter for this thread |
| 102 |
C I - Loop counter |
| 103 |
INTEGER I, myCurrentIter |
| 104 |
REAL myCurrentTime |
| 105 |
|
| 106 |
C-- Set model initial conditions |
| 107 |
CALL INITIALISE( myThid ) |
| 108 |
myCurrentTime = startTime |
| 109 |
myCurrentIter = nIter0 |
| 110 |
|
| 111 |
C-- Begin time stepping loop |
| 112 |
DO I=1, nTimeSteps |
| 113 |
|
| 114 |
C-- Load offline tracer fields |
| 115 |
IF ( MOD(myCurrentIter,numStepsPerPickup) .EQ. 1 ) THEN |
| 116 |
C I/O |
| 117 |
C o Writes to arrays are performed by their own thread (to ensure |
| 118 |
C physical memory allocation will pair with thread). |
| 119 |
C o Thread 1 reads into a buffer. |
| 120 |
C CALL LOAD_OFFLINE_FIELDS( myCurrentTime, myCurrentIter, myThid ) |
| 121 |
ENDIF |
| 122 |
|
| 123 |
C-- Step forward fields and calculate time tendency terms |
| 124 |
CALL DYNAMICS( myCurrentTime, myCurrentIter, myThid ) |
| 125 |
|
| 126 |
C-- Do IO if needed. |
| 127 |
C Note: |
| 128 |
C ===== |
| 129 |
C At this point model arrays hold U,V,T,S at "time-level" N |
| 130 |
C and cg2d_x at "time-level" N-1/2 where N = I+timeLevBase-1. |
| 131 |
C By convention this is taken to be the model "state". |
| 132 |
CALL DO_THE_MODEL_IO( myCurrentTime, myCurrentIter, myThid ) |
| 133 |
|
| 134 |
C-- Solve elliptic equation(s). |
| 135 |
C Two-dimensional only for conventional hydrostatic or |
| 136 |
C three-dimensional for non-hydrostatic and/or IGW scheme. |
| 137 |
CALL SOLVE_FOR_PRESSURE( myThid ) |
| 138 |
|
| 139 |
C-- Do "blocking" sends and receives for tendency "overlap" terms |
| 140 |
CALL DO_GTERM_BLOCKING_EXCHANGES( myThid ) |
| 141 |
|
| 142 |
myCurrentIter = myCurrentIter + 1 |
| 143 |
myCurrentTime = myCurrentTime + deltaTClock |
| 144 |
|
| 145 |
C-- Save state for restarts |
| 146 |
C Note: |
| 147 |
C ===== |
| 148 |
C Because of the ordereing of the timestepping code and |
| 149 |
C tendency term code at end of loop model arrays hold |
| 150 |
C U,V,T,S at "time-level" N but gu, gv, gs, gt, guNM1,... |
| 151 |
C at "time-level" N+1/2 (guNM1 at "time-level" N+1/2 is |
| 152 |
C gu at "time-level" N-1/2) and cg2d_x at "time-level" N+1/2. |
| 153 |
C where N = I+timeLevBase-1 |
| 154 |
C Thus a checkpoint contains U.0000000000, GU.0000000001 and |
| 155 |
C cg2d_x.0000000001 in the indexing scheme used for the model |
| 156 |
C "state" files. This example is referred to as a checkpoint |
| 157 |
C at time level 1 |
| 158 |
CALL WRITE_CHECKPOINT( .FALSE., myCurrentTime, myCurrentIter, myThid ) |
| 159 |
|
| 160 |
ENDDO |
| 161 |
|
| 162 |
C-- Dump for end state and final checkpoint |
| 163 |
CALL WRITE_STATE( myCurrentTime, myCurrentIter, myThid ) |
| 164 |
CALL WRITE_CHECKPOINT( .TRUE., myCurrentTime, myCurrentIter, myThid ) |
| 165 |
|
| 166 |
|
| 167 |
RETURN |
| 168 |
END |
Parent Directory
| 
Revision Log
| 
Revision Graph