Actual source code: ex15.c

  1: #include "petscsf.h"
  2: static char help[] = "Demonstrate CGNS parallel load-save-reload cycle, including data\n\n";

  4: #include <petscdmplex.h>
  5: #include <petscviewerhdf5.h>
  6: #define EX "ex15.c"

  8: typedef struct {
  9:   char      infile[PETSC_MAX_PATH_LEN];  /* Input mesh filename */
 10:   char      outfile[PETSC_MAX_PATH_LEN]; /* Dump/reload mesh filename */
 11:   PetscBool heterogeneous;               /* Test save on N / load on M */
 12:   PetscInt  ntimes;                      /* How many times do the cycle */
 13: } AppCtx;

 15: static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
 16: {
 17:   PetscBool flg;

 19:   PetscFunctionBeginUser;
 20:   options->infile[0]     = '\0';
 21:   options->outfile[0]    = '\0';
 22:   options->heterogeneous = PETSC_FALSE;
 23:   options->ntimes        = 2;
 24:   PetscOptionsBegin(comm, "", "Meshing Problem Options", "DMPLEX");
 25:   PetscCall(PetscOptionsString("-infile", "The input CGNS file", EX, options->infile, options->infile, sizeof(options->infile), &flg));
 26:   PetscCall(PetscOptionsString("-outfile", "The output CGNS file", EX, options->outfile, options->outfile, sizeof(options->outfile), &flg));
 27:   PetscCall(PetscOptionsBool("-heterogeneous", "Test save on N / load on M", EX, options->heterogeneous, &options->heterogeneous, NULL));
 28:   PetscCall(PetscOptionsInt("-ntimes", "How many times do the cycle", EX, options->ntimes, &options->ntimes, NULL));
 29:   PetscOptionsEnd();
 30:   PetscCheck(flg, comm, PETSC_ERR_USER_INPUT, "-infile needs to be specified");
 31:   PetscCheck(flg, comm, PETSC_ERR_USER_INPUT, "-outfile needs to be specified");
 32:   PetscFunctionReturn(PETSC_SUCCESS);
 33: }

 35: // @brief Create DM from CGNS file and setup PetscFE to VecLoad solution from that file
 36: PetscErrorCode ReadCGNSDM(MPI_Comm comm, const char filename[], DM *dm)
 37: {
 38:   PetscInt degree;

 40:   PetscFunctionBeginUser;
 41:   PetscCall(DMPlexCreateFromFile(comm, filename, "ex15_plex", PETSC_TRUE, dm));
 42:   PetscCall(DMPlexDistributeSetDefault(*dm, PETSC_FALSE));
 43:   PetscCall(DMSetFromOptions(*dm));
 44:   PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view"));

 46:   /* Redistribute */
 47:   PetscCall(DMSetOptionsPrefix(*dm, "redistributed_"));
 48:   PetscCall(DMSetFromOptions(*dm));
 49:   PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view"));

 51:   { // Get degree of the natural section
 52:     PetscFE        fe_natural;
 53:     PetscDualSpace dual_space_natural;

 55:     PetscCall(DMGetField(*dm, 0, NULL, (PetscObject *)&fe_natural));
 56:     PetscCall(PetscFEGetDualSpace(fe_natural, &dual_space_natural));
 57:     PetscCall(PetscDualSpaceGetOrder(dual_space_natural, &degree));
 58:     PetscCall(DMClearFields(*dm));
 59:     PetscCall(DMSetLocalSection(*dm, NULL));
 60:   }

 62:   { // Setup fe to load in the initial condition data
 63:     PetscFE  fe;
 64:     PetscInt dim;

 66:     PetscCall(DMGetDimension(*dm, &dim));
 67:     PetscCall(PetscFECreateLagrange(PETSC_COMM_SELF, dim, 5, PETSC_FALSE, degree, PETSC_DETERMINE, &fe));
 68:     PetscCall(PetscObjectSetName((PetscObject)fe, "FE for VecLoad"));
 69:     PetscCall(DMAddField(*dm, NULL, (PetscObject)fe));
 70:     PetscCall(DMCreateDS(*dm));
 71:     PetscCall(PetscFEDestroy(&fe));
 72:   }

 74:   // Set section component names, used when writing out CGNS files
 75:   PetscSection section;
 76:   PetscCall(DMGetLocalSection(*dm, &section));
 77:   PetscCall(PetscSectionSetFieldName(section, 0, ""));
 78:   PetscCall(PetscSectionSetComponentName(section, 0, 0, "Pressure"));
 79:   PetscCall(PetscSectionSetComponentName(section, 0, 1, "VelocityX"));
 80:   PetscCall(PetscSectionSetComponentName(section, 0, 2, "VelocityY"));
 81:   PetscCall(PetscSectionSetComponentName(section, 0, 3, "VelocityZ"));
 82:   PetscCall(PetscSectionSetComponentName(section, 0, 4, "Temperature"));
 83:   PetscFunctionReturn(PETSC_SUCCESS);
 84: }

 86: // Verify that V_load is equivalent to V_serial, even if V_load is distributed
 87: PetscErrorCode VerifyLoadedSolution(DM dm_serial, Vec V_serial, DM dm_load, Vec V_load, PetscScalar tol)
 88: {
 89:   MPI_Comm     comm = PetscObjectComm((PetscObject)dm_load);
 90:   PetscSF      load_to_serial_sf;
 91:   PetscScalar *array_load_bcast = NULL;
 92:   PetscInt     num_comps        = 5;

 94:   PetscFunctionBeginUser;
 95:   { // Create SF to broadcast loaded vec nodes to serial vec nodes
 96:     PetscInt           dim, num_local_serial = 0, num_local_load;
 97:     Vec                coord_Vec_serial, coord_Vec_load;
 98:     const PetscScalar *coord_serial = NULL, *coord_load;

100:     PetscCall(DMGetCoordinateDim(dm_load, &dim));
101:     PetscCall(DMGetCoordinates(dm_load, &coord_Vec_load));
102:     PetscCall(VecGetLocalSize(coord_Vec_load, &num_local_load));
103:     num_local_load /= dim;

105:     PetscCall(VecGetArrayRead(coord_Vec_load, &coord_load));

107:     if (dm_serial) {
108:       PetscCall(DMGetCoordinates(dm_serial, &coord_Vec_serial));
109:       PetscCall(VecGetLocalSize(coord_Vec_serial, &num_local_serial));
110:       num_local_serial /= dim;
111:       PetscCall(VecGetArrayRead(coord_Vec_serial, &coord_serial));
112:     }

114:     PetscCall(PetscSFCreate(comm, &load_to_serial_sf));
115:     PetscCall(PetscSFSetGraphFromCoordinates(load_to_serial_sf, num_local_load, num_local_serial, dim, 100 * PETSC_MACHINE_EPSILON, coord_load, coord_serial));
116:     PetscCall(PetscSFViewFromOptions(load_to_serial_sf, NULL, "-verify_sf_view"));

118:     PetscCall(VecRestoreArrayRead(coord_Vec_load, &coord_load));
119:     if (dm_serial) PetscCall(VecRestoreArrayRead(coord_Vec_serial, &coord_serial));
120:   }

122:   { // Broadcast the loaded vector data into a serial-sized array
123:     PetscInt           size_local_serial = 0;
124:     const PetscScalar *array_load;
125:     MPI_Datatype       unit;

127:     PetscCall(VecGetArrayRead(V_load, &array_load));
128:     if (V_serial) {
129:       PetscCall(VecGetLocalSize(V_serial, &size_local_serial));
130:       PetscCall(PetscMalloc1(size_local_serial, &array_load_bcast));
131:     }

133:     PetscCallMPI(MPI_Type_contiguous(num_comps, MPIU_REAL, &unit));
134:     PetscCallMPI(MPI_Type_commit(&unit));
135:     PetscCall(PetscSFBcastBegin(load_to_serial_sf, unit, array_load, array_load_bcast, MPI_REPLACE));
136:     PetscCall(PetscSFBcastEnd(load_to_serial_sf, unit, array_load, array_load_bcast, MPI_REPLACE));
137:     PetscCallMPI(MPI_Type_free(&unit));
138:     PetscCall(VecRestoreArrayRead(V_load, &array_load));
139:   }

141:   if (V_serial) {
142:     const PetscScalar *array_serial;
143:     PetscInt           size_local_serial;

145:     PetscCall(VecGetArrayRead(V_serial, &array_serial));
146:     PetscCall(VecGetLocalSize(V_serial, &size_local_serial));
147:     for (PetscInt i = 0; i < size_local_serial; i++) {
148:       if (PetscAbs(array_serial[i] - array_load_bcast[i]) > tol) PetscCall(PetscPrintf(comm, "DoF %" PetscInt_FMT " is inconsistent. Found %g, expected %g\n", i, array_load_bcast[i], array_serial[i]));
149:     }
150:     PetscCall(VecRestoreArrayRead(V_serial, &array_serial));
151:   }

153:   PetscCall(PetscFree(array_load_bcast));
154:   PetscCall(PetscSFDestroy(&load_to_serial_sf));
155:   PetscFunctionReturn(PETSC_SUCCESS);
156: }

158: int main(int argc, char **argv)
159: {
160:   AppCtx      user;
161:   MPI_Comm    comm;
162:   PetscMPIInt gsize, grank, mycolor;
163:   PetscBool   flg;
164:   const char *infilename;
165:   DM          dm_serial = NULL;
166:   Vec         V_serial  = NULL;

168:   PetscFunctionBeginUser;
169:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
170:   PetscCall(ProcessOptions(PETSC_COMM_WORLD, &user));
171:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &gsize));
172:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &grank));

174:   { // Read infile in serial
175:     PetscViewer viewer;
176:     PetscMPIInt gsize_serial;

178:     mycolor = grank == 0 ? 0 : 1;
179:     PetscCallMPI(MPI_Comm_split(PETSC_COMM_WORLD, mycolor, grank, &comm));

181:     if (grank == 0) {
182:       PetscCallMPI(MPI_Comm_size(comm, &gsize_serial));

184:       PetscCall(ReadCGNSDM(comm, user.infile, &dm_serial));
185:       PetscCall(DMSetOptionsPrefix(dm_serial, "serial_"));

187:       /* We just test/demonstrate DM is indeed distributed - unneeded in the application code */
188:       PetscCall(DMPlexIsDistributed(dm_serial, &flg));
189:       PetscCall(PetscPrintf(comm, "Loaded mesh distributed? %s\n", PetscBools[flg]));

191:       PetscCall(DMViewFromOptions(dm_serial, NULL, "-dm_view"));
192:       PetscCall(PetscViewerCGNSOpen(comm, user.infile, FILE_MODE_READ, &viewer));
193:       PetscCall(DMGetGlobalVector(dm_serial, &V_serial));
194:       PetscCall(VecLoad(V_serial, viewer));
195:       PetscCall(PetscViewerDestroy(&viewer));
196:       PetscCallMPI(MPI_Comm_free(&comm));
197:     }
198:     PetscCallMPI(MPI_Barrier(PETSC_COMM_WORLD));
199:   }

201:   for (PetscInt i = 0; i < user.ntimes; i++) {
202:     if (i == 0) {
203:       /* Use infile for the initial load */
204:       infilename = user.infile;
205:     } else {
206:       /* Use outfile for all I/O except the very initial load */
207:       infilename = user.outfile;
208:     }

210:     if (user.heterogeneous) {
211:       mycolor = (PetscMPIInt)(grank > user.ntimes - i);
212:     } else {
213:       mycolor = (PetscMPIInt)0;
214:     }
215:     PetscCallMPI(MPI_Comm_split(PETSC_COMM_WORLD, mycolor, grank, &comm));

217:     if (mycolor == 0) {
218:       /* Load/Save only on processes with mycolor == 0 */
219:       DM          dm;
220:       Vec         V;
221:       PetscViewer viewer;
222:       PetscMPIInt comm_size;
223:       const char *name;
224:       PetscReal   time;
225:       PetscBool   set;

227:       PetscCallMPI(MPI_Comm_size(comm, &comm_size));
228:       PetscCall(PetscPrintf(comm, "Begin cycle %" PetscInt_FMT ", comm size %" PetscInt_FMT "\n", i, comm_size));

230:       // Load DM from CGNS file
231:       PetscCall(ReadCGNSDM(comm, infilename, &dm));
232:       PetscCall(DMSetOptionsPrefix(dm, "loaded_"));
233:       PetscCall(DMViewFromOptions(dm, NULL, "-dm_view"));

235:       // Load solution from CGNS file
236:       PetscCall(PetscViewerCGNSOpen(comm, infilename, FILE_MODE_READ, &viewer));
237:       PetscCall(DMGetGlobalVector(dm, &V));
238:       PetscCall(PetscViewerCGNSSetSolutionIndex(viewer, 1));
239:       { // Test GetSolutionIndex, not needed in application code
240:         PetscInt solution_index;
241:         PetscCall(PetscViewerCGNSGetSolutionIndex(viewer, &solution_index));
242:         PetscCheck(solution_index == 1, comm, PETSC_ERR_ARG_INCOMP, "Returned solution index wrong.");
243:       }
244:       PetscCall(PetscViewerCGNSGetSolutionName(viewer, &name));
245:       PetscCall(PetscViewerCGNSGetSolutionTime(viewer, &time, &set));
246:       PetscCheck(set, comm, PETSC_ERR_RETURN, "Time data wasn't set!");
247:       PetscCall(PetscPrintf(comm, "Solution Name: %s, and time %g\n", name, time));
248:       PetscCall(VecLoad(V, viewer));
249:       PetscCall(PetscViewerDestroy(&viewer));

251:       // Verify loaded solution against serial solution
252:       PetscCall(VerifyLoadedSolution(dm_serial, V_serial, dm, V, 100 * PETSC_MACHINE_EPSILON));

254:       // Write loaded solution to CGNS file
255:       PetscCall(PetscViewerCGNSOpen(comm, user.outfile, FILE_MODE_WRITE, &viewer));
256:       PetscCall(VecView(V, viewer));
257:       PetscCall(PetscViewerDestroy(&viewer));

259:       PetscCall(DMRestoreGlobalVector(dm, &V));
260:       PetscCall(DMDestroy(&dm));
261:       PetscCall(PetscPrintf(comm, "End   cycle %" PetscInt_FMT "\n--------\n", i));
262:     }
263:     PetscCallMPI(MPI_Comm_free(&comm));
264:     PetscCallMPI(MPI_Barrier(PETSC_COMM_WORLD));
265:   }

267:   if (V_serial && dm_serial) PetscCall(DMRestoreGlobalVector(dm_serial, &V_serial));
268:   if (dm_serial) PetscCall(DMDestroy(&dm_serial));
269:   PetscCall(PetscFinalize());
270:   return 0;
271: }

273: /*TEST
274:   build:
275:     requires: cgns
276:   testset:
277:     suffix: cgns
278:     requires: !complex
279:     nsize: 4
280:     args: -infile ${wPETSC_DIR}/share/petsc/datafiles/meshes/2x2x2_Q3_wave.cgns -outfile 2x2x2_Q3_wave_output.cgns
281:     args: -dm_plex_cgns_parallel -ntimes 3 -heterogeneous -serial_dm_view -loaded_dm_view -redistributed_dm_distribute
282:     test:
283:       # this partitioner should not shuffle anything, it should yield the same partitioning as the XDMF reader - added just for testing
284:       suffix: simple
285:       args: -petscpartitioner_type simple
286:     test:
287:       suffix: parmetis
288:       requires: parmetis
289:       args: -petscpartitioner_type parmetis
290:     test:
291:       suffix: ptscotch
292:       requires: ptscotch
293:       args: -petscpartitioner_type ptscotch

295: TEST*/