Domain decomposition scheme now also read from parameter file.

examples/main.c

@@ -52,18 +52,18 @@ void print_help_message() {
   printf("  %2s %8s %s\n", "-c", "", "Run with cosmological time integration");
   printf("  %2s %8s %s\n", "-e", "",
          "Enable floating-point exceptions (debugging mode)");
-  printf("  %2s %8s %s\n", "-f", "[value] ",
-         "Overwrites the CPU frequency (Hz) to be used for time measurements");
+  printf("  %2s %8s %s\n", "-f", "{int}",
+         "Overwrite the CPU frequency (Hz) to be used for time measurements");
   printf("  %2s %8s %s\n", "-g", "",
          "Run with an external gravitational potential");
   printf("  %2s %8s %s\n", "-G", "", "Run with self-gravity");
   printf("  %2s %8s %s\n", "-s", "", "Run with SPH");
-  printf("  %2s %8s %s\n", "-v", "[12]   ",
+  printf("  %2s %8s %s\n", "-v", "[12]",
          "Increase the level of verbosity 1: MPI-rank 0 writes "
-         "2: All MPI ranks write");
-  printf("  %2s %8s %s\n", "-y", "",
+         "2: All MPI-ranks write");
+  printf("  %2s %8s %s\n", "-y", "{int}",
          "Time-step frequency at which task graphs are dumped");
-  printf("  %2s %8s %s\n", "-h", "", "Prints this help message and exits");
+  printf("  %2s %8s %s\n", "-h", "", "Print this help message and exit");
   printf("\nSee the file example.yml for an example of parameter file.\n");
 }
 
@@ -75,22 +75,8 @@ int main(int argc, char *argv[]) {
 
   struct clocks_time tic, toc;
 
-#ifdef WITH_MPI
-  struct partition initial_partition;
-  enum repartition_type reparttype = REPART_NONE;
-
-  initial_partition.type = INITPART_GRID;
-  initial_partition.grid[0] = 1;
-  initial_partition.grid[1] = 1;
-  initial_partition.grid[2] = 1;
-#ifdef HAVE_METIS
-  /* Defaults make use of METIS. */
-  reparttype = REPART_METIS_BOTH;
-  initial_partition.type = INITPART_METIS_NOWEIGHT;
-#endif
-#endif
-
   int nr_nodes = 1, myrank = 0;
+
 #ifdef WITH_MPI
   /* Start by initializing MPI. */
   int res = 0, prov = 0;
@@ -111,19 +97,13 @@ int main(int argc, char *argv[]) {
   if (myrank == 0)
     printf("[0000][00000.0] MPI is up and running with %i node(s).\n",
            nr_nodes);
+  if (nr_nodes == 1) {
+    message("WARNING: you are running with one MPI rank.");
+    message("WARNING: you should use the non-MPI version of this program.");
+  }
   fflush(stdout);
-
-  /* Set a default grid so that grid[0]*grid[1]*grid[2] == nr_nodes. */
-  factor(nr_nodes, &initial_partition.grid[0], &initial_partition.grid[1]);
-  factor(nr_nodes / initial_partition.grid[1], &initial_partition.grid[0],
-         &initial_partition.grid[2]);
-  factor(initial_partition.grid[0] * initial_partition.grid[1],
-         &initial_partition.grid[1], &initial_partition.grid[0]);
 #endif
 
-  /* Greeting message */
-  if (myrank == 0) greetings();
-
 #if defined(HAVE_SETAFFINITY) && defined(HAVE_LIBNUMA) && defined(_GNU_SOURCE)
   if ((ENGINE_POLICY) & engine_policy_setaffinity) {
     /* Ensure the NUMA node on which we initialise (first touch) everything
@@ -139,6 +119,9 @@ int main(int argc, char *argv[]) {
   }
 #endif
 
+  /* Welcome to SWIFT, you made the right choice */
+  if (myrank == 0) greetings();
+
   int dump_tasks = 0;
   int with_cosmology = 0;
   int with_external_gravity = 0;
@@ -209,7 +192,7 @@ int main(int argc, char *argv[]) {
     exit(1);
   }
 
-  /* And then, there was time ! */
+  /* Genesis 1.1: And then, there was time ! */
   clocks_set_cpufreq(cpufreq);
 
   /* Report CPU frequency. */
@@ -244,7 +227,7 @@ int main(int argc, char *argv[]) {
   }
 #ifdef WITH_MPI
   /* Broadcast the parameter file */
-  MPI_Bcast(&params, sizeof(struct swift_params), MPI_BYTE, MPI_COMM_WORLD);
+  MPI_Bcast(&params, sizeof(struct swift_params), MPI_BYTE, 0, MPI_COMM_WORLD);
 #endif
 
   /* Initialize unit system */
@@ -258,25 +241,21 @@ int main(int argc, char *argv[]) {
     message("Unit system: U_T = %e K.", us.UnitTemperature_in_cgs);
   }
 
-/* Some initial information about domain decomposition */
+/* Prepare the domain decomposition scheme */
 #ifdef WITH_MPI
+  struct partition initial_partition;
+  enum repartition_type reparttype;
+  partition_init(&initial_partition, &reparttype, &params, nr_nodes);
+
+  /* Let's report what we did */
   if (myrank == 0) {
-    // message("Running with %i thread(s) per node.", nr_threads);
     message("Using initial partition %s",
             initial_partition_name[initial_partition.type]);
     if (initial_partition.type == INITPART_GRID)
       message("grid set to [ %i %i %i ].", initial_partition.grid[0],
               initial_partition.grid[1], initial_partition.grid[2]);
     message("Using %s repartitioning", repartition_name[reparttype]);
-
-    if (nr_nodes == 1) {
-      message("WARNING: you are running with one MPI rank.");
-      message("WARNING: you should use the non-MPI version of this program.");
-    }
-    fflush(stdout);
   }
-#else
-// if (myrank == 0) message("Running with %i thread(s).", nr_threads);
 #endif
 
   /* Read particles and space information from (GADGET) ICs */
@@ -432,11 +411,10 @@ int main(int argc, char *argv[]) {
 
   /* Legend */
   if (myrank == 0)
-    printf("# %6s %14s %14s %10s %10s %16s [%s]\n",
-	   "Step",  "Time",  "Time-step",  "Updates", "g-Updates",
-	   "Wall-clock time", clocks_getunit());
+    printf("# %6s %14s %14s %10s %10s %16s [%s]\n", "Step", "Time", "Time-step",
+           "Updates", "g-Updates", "Wall-clock time", clocks_getunit());
 
-  /* Let loose a runner on the space. */
+  /* Main simulation loop */
   for (int j = 0; !engine_is_done(&e); j++) {
 
 /* Repartition the space amongst the nodes? */

src/engine.c

@@ -2325,8 +2325,9 @@ static bool hyperthreads_present(void) {
  * @param verbose Is this #engine talkative ?
  */
 
-void engine_init(struct engine *e, struct space *s, struct swift_params *params,
-                 int nr_nodes, int nodeID, int policy, int verbose) {
+void engine_init(struct engine *e, struct space *s,
+                 const struct swift_params *params, int nr_nodes, int nodeID,
+                 int policy, int verbose) {
 
   /* Clean-up everything */
   bzero(e, sizeof(struct engine));

src/engine.h

@@ -168,8 +168,9 @@ struct engine {
 
 /* Function prototypes. */
 void engine_barrier(struct engine *e, int tid);
-void engine_init(struct engine *e, struct space *s, struct swift_params *params,
-                 int nr_nodes, int nodeID, int policy, int verbose);
+void engine_init(struct engine *e, struct space *s,
+                 const struct swift_params *params, int nr_nodes, int nodeID,
+                 int policy, int verbose);
 void engine_launch(struct engine *e, int nr_runners, unsigned int mask,
                    unsigned int submask);
 void engine_prepare(struct engine *e);

src/parser.c

@@ -313,6 +313,38 @@ int parser_get_param_int(const struct swift_params *params, const char *name) {
   return 0;
 }
 
+/**
+ * @brief Retrieve char parameter from structure.
+ *
+ * @param params Structure that holds the parameters
+ * @param name Name of the parameter to be found
+ * @return Value of the parameter found
+ */
+char parser_get_param_char(const struct swift_params *params,
+                           const char *name) {
+
+  char str[PARSER_MAX_LINE_SIZE];
+  char retParam = 0;
+
+  for (int i = 0; i < params->count; i++) {
+    /*strcmp returns 0 if both strings are the same.*/
+    if (!strcmp(name, params->data[i].name)) {
+      /* Check that exactly one number is parsed. */
+      if (sscanf(params->data[i].value, "%c%s", &retParam, str) != 1) {
+        error(
+            "Tried parsing char '%s' but found '%s' with illegal char "
+            "characters '%s'.",
+            params->data[i].name, params->data[i].value, str);
+      }
+
+      return retParam;
+    }
+  }
+
+  error("Cannot find '%s' in the structure.", name);
+  return 0;
+}
+
 /**
  * @brief Retrieve float parameter from structure.
  *

src/parser.h

@@ -43,6 +43,7 @@ void parser_read_file(const char *file_name, struct swift_params *params);
 void parser_print_params(const struct swift_params *params);
 void parser_write_params_to_file(const struct swift_params *params,
                                  const char *file_name);
+char parser_get_param_char(const struct swift_params *params, const char *name);
 int parser_get_param_int(const struct swift_params *params, const char *name);
 float parser_get_param_float(const struct swift_params *params,
                              const char *name);

src/partition.c

@@ -52,6 +52,7 @@
 #include "error.h"
 #include "partition.h"
 #include "space.h"
+#include "tools.h"
 
 /* Maximum weight used for METIS. */
 #define metis_maxweight 10000.0f
@@ -907,6 +908,111 @@ void partition_initial_partition(struct partition *initial_partition,
   }
 }
 
+/**
+ * @brief Initialises the partition and re-partition scheme from the parameter
+ *file
+ *
+ * @param partition The #partition scheme to initialise.
+ * @param reparttype The repartition scheme to initialise.
+ * @param params The parsed parameter file.
+ * @param nr_nodes The number of MPI nodes we are running on.
+ */
+void partition_init(struct partition *partition,
+                    enum repartition_type *reparttype,
+                    const struct swift_params *params, int nr_nodes) {
+
+#ifdef WITH_MPI
+
+/* Defaults make use of METIS if available */
+#ifdef HAVE_METIS
+  *reparttype = REPART_METIS_BOTH;
+  partition->type = INITPART_METIS_NOWEIGHT;
+#else
+  *reparttype = REPART_NONE;
+  partition->type = INITPART_GRID;
+#endif
+
+  /* Set a default grid so that grid[0]*grid[1]*grid[2] == nr_nodes. */
+  factor(nr_nodes, &partition->grid[0], &partition->grid[1]);
+  factor(nr_nodes / partition->grid[1], &partition->grid[0],
+         &partition->grid[2]);
+  factor(partition->grid[0] * partition->grid[1], &partition->grid[1],
+         &partition->grid[0]);
+
+  /* Now let's check what the user wants as an initial domain*/
+  const char part_type =
+      parser_get_param_char(params, "DomainDecomposition:initial_type");
+
+  switch (part_type) {
+    case 'g':
+      partition->type = INITPART_GRID;
+      break;
+    case 'v':
+      partition->type = INITPART_VECTORIZE;
+      break;
+#ifdef HAVE_METIS
+    case 'm':
+      partition->type = INITPART_METIS_NOWEIGHT;
+      break;
+    case 'w':
+      partition->type = INITPART_METIS_WEIGHT;
+      break;
+    default:
+      message("Invalid choice of initial partition type '%c'.", part_type);
+      error("Permitted values are: 'g','m','v' or 'w'.");
+#else
+    default:
+      message("Invalid choice of initial partition type '%c'.", part_type);
+      error("Permitted values are: 'g' or 'v' when compiled without metis.");
+#endif
+  }
+
+  /* In case of grid, read more parameters */
+  if (part_type == 'g') {
+    partition->grid[0] =
+        parser_get_param_int(params, "DomainDecomposition:initial_grid_x");
+    partition->grid[1] =
+        parser_get_param_int(params, "DomainDecomposition:initial_grid_y");
+    partition->grid[2] =
+        parser_get_param_int(params, "DomainDecomposition:initial_grid_z");
+  }
+
+  /* Now let's check what the user wants as a repartition strategy */
+  const char repart_type =
+      parser_get_param_char(params, "DomainDecomposition:repartition_type");
+
+  switch (repart_type) {
+    case 'n':
+      *reparttype = REPART_NONE;
+      break;
+#ifdef HAVE_METIS
+    case 'b':
+      *reparttype = REPART_METIS_BOTH;
+      break;
+    case 'e':
+      *reparttype = REPART_METIS_EDGE;
+      break;
+    case 'v':
+      *reparttype = REPART_METIS_VERTEX;
+      break;
+    case 'x':
+      *reparttype = REPART_METIS_VERTEX_EDGE;
+      break;
+    default:
+      message("Invalid choice of re-partition type '%c'.", repart_type);
+      error("Permitted values are: 'b','e','n', 'v' or 'x'.");
+#else
+    default:
+      message("Invalid choice of re-partition type '%c'.", repart_type);
+      error("Permitted values are: 'n' when compiled without metis.");
+#endif
+  }
+
+#else
+  error("SWIFT was not compiled with MPI support");
+#endif
+}
+
 /*  General support */
 /*  =============== */
 

src/partition.h

@@ -19,6 +19,7 @@
 #ifndef SWIFT_PARTITION_H
 #define SWIFT_PARTITION_H
 
+#include "parser.h"
 #include "space.h"
 #include "task.h"
 
@@ -56,4 +57,8 @@ void partition_repartition(enum repartition_type reparttype, int nodeID,
 void partition_initial_partition(struct partition *initial_partition,
                                  int nodeID, int nr_nodes, struct space *s);
 
+void partition_init(struct partition *partition,
+                    enum repartition_type *reparttypestruct,
+                    const struct swift_params *params, int nr_nodes);
+
 #endif /* SWIFT_PARTITION_H */

src/space.c

@@ -1277,9 +1277,9 @@ struct cell *space_getcell(struct space *s) {
  * recursively.
  */
 
-void space_init(struct space *s, struct swift_params *params, double dim[3],
-                struct part *parts, struct gpart *gparts, size_t Npart,
-                size_t Ngpart, int periodic, int verbose) {
+void space_init(struct space *s, const struct swift_params *params,
+                double dim[3], struct part *parts, struct gpart *gparts,
+                size_t Npart, size_t Ngpart, int periodic, int verbose) {
 
   /* Clean-up everything */
   bzero(s, sizeof(struct space));

src/space.h

@@ -132,9 +132,9 @@ void space_gparts_sort(struct gpart *gparts, int *ind, size_t N, int min,
 struct cell *space_getcell(struct space *s);
 int space_getsid(struct space *s, struct cell **ci, struct cell **cj,
                  double *shift);
-void space_init(struct space *s, struct swift_params *params, double dim[3],
-                struct part *parts, struct gpart *gparts, size_t Npart,
-                size_t Ngpart, int periodic, int verbose);
+void space_init(struct space *s, const struct swift_params *params,
+                double dim[3], struct part *parts, struct gpart *gparts,
+                size_t Npart, size_t Ngpart, int periodic, int verbose);
 void space_map_cells_pre(struct space *s, int full,
                          void (*fun)(struct cell *c, void *data), void *data);
 void space_map_parts(struct space *s,

src/version.c

@@ -241,7 +241,7 @@ const char *metis_version(void) {
  */
 void greetings(void) {
 
-  printf(" Welcome to the cosmological code\n");
+  printf(" Welcome to the cosmological hydrodynamical code\n");
   printf("    ______       _________________\n");
   printf("   / ___/ |     / /  _/ ___/_  __/\n");
   printf("   \\__ \\| | /| / // // /_   / /   \n");