Synchronize and Update variants. Prepare Assigment codes.

BasicSolver/2D-mpi-v1/src/main.c

@@ -15,12 +15,11 @@
 #include "progress.h"
 #include "solver.h"
 #include "timing.h"
-#include <mpi.h>
 
 int main(int argc, char** argv)
 {
-    int rank;
-    double S, E;
+    int rank = 0;
+    double start, end;
     Parameter params;
     Solver solver;
 
@@ -44,7 +43,7 @@ int main(int argc, char** argv)
     double te  = solver.te;
     double t   = 0.0;
 
-    S = getTimeStamp();
+    start = getTimeStamp();
     while (t <= te) {
         if (tau > 0.0) {
             computeTimestep(&solver);
@@ -56,7 +55,6 @@ int main(int argc, char** argv)
         computeRHS(&solver);
         solve(&solver);
         adaptUV(&solver);
-        /* exit(EXIT_SUCCESS); */
         t += solver.dt;
 
 #ifdef VERBOSE
@@ -67,10 +65,10 @@ int main(int argc, char** argv)
         printProgress(t);
 #endif
     }
-    E = getTimeStamp();
+    end = getTimeStamp();
     stopProgress();
     if (rank == 0) {
-        printf("Solution took %.2fs\n", E - S);
+        printf("Solution took %.2fs\n", end - start);
     }
     collectResult(&solver);
 

BasicSolver/2D-mpi-v1/src/solver.c

@@ -108,64 +108,69 @@ static void shift(Solver* solver)
     MPI_Waitall(2, requests, MPI_STATUSES_IGNORE);
 }
 
-void collectResult(Solver* solver)
+static void gatherArray(
+    Solver* solver, int cnt, int* rcvCounts, int* displs, double* src, double* dst)
 {
-    double* Pall = NULL;
-    double* Uall = NULL;
-    double* Vall = NULL;
-    int *rcvCounts, *displs;
+    double* sendbuffer = src + (solver->imax + 2);
 
     if (solver->rank == 0) {
-        Pall = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
-        Uall = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
-        Vall = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
+        sendbuffer = src;
+    }
+
+    MPI_Gatherv(sendbuffer,
+        cnt,
+        MPI_DOUBLE,
+        dst,
+        rcvCounts,
+        displs,
+        MPI_DOUBLE,
+        0,
+        MPI_COMM_WORLD);
+}
+
+void collectResult(Solver* solver)
+{
+    double* p = NULL;
+    double* u = NULL;
+    double* v = NULL;
+    int *rcvCounts, *displs;
+    int cnt = solver->jmaxLocal * (solver->imax + 2);
+
+    if (solver->rank == 0) {
+        p = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
+        u = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
+        v = allocate(64, (solver->imax + 2) * (solver->jmax + 2) * sizeof(double));
         rcvCounts    = (int*)malloc(solver->size * sizeof(int));
         displs       = (int*)malloc(solver->size * sizeof(int));
-        rcvCounts[0] = solver->jmaxLocal * (solver->imax + 2);
+    }
+
+    if (solver->rank == 0 && solver->size == 1) {
+        cnt = (solver->jmaxLocal + 2) * (solver->imax + 2);
+    } else if (solver->rank == 0 || solver->rank == (solver->size - 1)) {
+        cnt = (solver->jmaxLocal + 1) * (solver->imax + 2);
+    }
+
+    MPI_Gather(&cnt, 1, MPI_INTEGER, rcvCounts, 1, MPI_INTEGER, 0, MPI_COMM_WORLD);
+
+    if (solver->rank == 0) {
         displs[0]    = 0;
         int cursor   = rcvCounts[0];
 
         for (int i = 1; i < solver->size; i++) {
-            rcvCounts[i] = sizeOfRank(i, solver->size, solver->jmax) * (solver->imax + 2);
             displs[i]    = cursor;
             cursor += rcvCounts[i];
         }
     }
 
-    int cnt            = solver->jmaxLocal * (solver->imax + 2);
-    double* sendbuffer = solver->p + (solver->imax + 2);
-    MPI_Gatherv(sendbuffer,
-        cnt,
-        MPI_DOUBLE,
-        Pall,
-        rcvCounts,
-        displs,
-        MPI_DOUBLE,
-        0,
-        MPI_COMM_WORLD);
-    sendbuffer = solver->u + (solver->imax + 2);
-    MPI_Gatherv(sendbuffer,
-        cnt,
-        MPI_DOUBLE,
-        Uall,
-        rcvCounts,
-        displs,
-        MPI_DOUBLE,
-        0,
-        MPI_COMM_WORLD);
-    sendbuffer = solver->v + (solver->imax + 2);
-    MPI_Gatherv(sendbuffer,
-        cnt,
-        MPI_DOUBLE,
-        Vall,
-        rcvCounts,
-        displs,
-        MPI_DOUBLE,
-        0,
-        MPI_COMM_WORLD);
+    gatherArray(solver, cnt, rcvCounts, displs, solver->p, p);
+    gatherArray(solver, cnt, rcvCounts, displs, solver->u, u);
+    gatherArray(solver, cnt, rcvCounts, displs, solver->v, v);
 
     if (solver->rank == 0) {
-        writeResult(solver, Pall, Uall, Vall);
+        writeResult(solver, p, u, v);
+        free(p);
+        free(u);
+        free(v);
     }
 }
 
@@ -253,8 +258,8 @@ void initSolver(Solver* solver, Parameter* params)
 
     double dx          = solver->dx;
     double dy          = solver->dy;
-    double inv_sqr_sum = 1.0 / (dx * dx) + 1.0 / (dy * dy);
-    solver->dtBound    = 0.5 * solver->re * 1.0 / inv_sqr_sum;
+    double invSquareSum = 1.0 / (dx * dx) + 1.0 / (dy * dy);
+    solver->dtBound     = 0.5 * solver->re * 1.0 / invSquareSum;
 #ifdef VERBOSE
     printConfig(solver);
 #endif
@@ -678,10 +683,10 @@ void writeResult(Solver* solver, double* p, double* u, double* v)
         y = dy * (j - 0.5);
         for (int i = 1; i < imax + 1; i++) {
             x            = dx * (i - 0.5);
-            double vel_u = (U(i, j) + U(i - 1, j)) / 2.0;
-            double vel_v = (V(i, j) + V(i, j - 1)) / 2.0;
-            double len   = sqrt((vel_u * vel_u) + (vel_v * vel_v));
-            fprintf(fp, "%.2f %.2f %f %f %f\n", x, y, vel_u, vel_v, len);
+            double vu  = (U(i, j) + U(i - 1, j)) / 2.0;
+            double vv  = (V(i, j) + V(i, j - 1)) / 2.0;
+            double len = sqrt((vu * vu) + (vv * vv));
+            fprintf(fp, "%.2f %.2f %f %f %f\n", x, y, vu, vv, len);
         }
     }