Added a sample for benchmarking

samples/benchmark/CMakeLists.txt

@@ -0,0 +1,3 @@
+## benchmark
+add_executable(benchmark main.cc)
+target_link_libraries(benchmark astaroth_core astaroth_utils)

samples/benchmark/main.cc

@@ -0,0 +1,122 @@
+/*
+    Copyright (C) 2014-2020, Johannes Pekkila, Miikka Vaisala.
+
+    This file is part of Astaroth.
+
+    Astaroth is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Astaroth is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Astaroth.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+    Running: benchmark -np <num processes> <executable>
+*/
+#include "astaroth.h"
+#include "astaroth_utils.h"
+
+#include "timer_hires.h"
+
+#if AC_MPI_ENABLED
+
+#include <mpi.h>
+
+#include <algorithm>
+#include <vector>
+
+int
+main(void)
+{
+    MPI_Init(NULL, NULL);
+    int nprocs, pid;
+    MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
+    MPI_Comm_rank(MPI_COMM_WORLD, &pid);
+
+    // CPU alloc
+    AcMeshInfo info;
+    acLoadConfig(AC_DEFAULT_CONFIG, &info);
+
+    /*
+    AcMesh model, candidate;
+    if (pid == 0) {
+        acMeshCreate(info, &model);
+        acMeshCreate(info, &candidate);
+        acMeshRandomize(&model);
+        acMeshRandomize(&candidate);
+    }*/
+
+    // GPU alloc & compute
+    acGridInit(info);
+    /*
+    acGridLoadMesh(model, STREAM_DEFAULT);
+
+    acGridIntegrate(STREAM_DEFAULT, FLT_EPSILON);
+    acGridPeriodicBoundconds(STREAM_DEFAULT);
+
+    acGridStoreMesh(STREAM_DEFAULT, &candidate);
+
+    // Verify
+    if (pid == 0) {
+        acModelIntegrateStep(model, FLT_EPSILON);
+        acMeshApplyPeriodicBounds(&model);
+
+        AcResult retval = acVerifyMesh(model, candidate);
+        acMeshDestroy(&model);
+        acMeshDestroy(&candidate);
+
+        if (retval != AC_SUCCESS) {
+            fprintf(stderr, "Failures found, benchmark invalid. Skipping\n");
+            return EXIT_FAILURE;
+        }
+    }*/
+
+    // Warmup
+    for (size_t i = 0; i < 10; ++i)
+        acGridIntegrate(STREAM_DEFAULT, FLT_EPSILON);
+
+    // Benchmark
+    Timer t;
+    const AcReal dt             = FLT_EPSILON;
+    const size_t num_iters      = 100;
+    const double nth_percentile = 0.90;
+
+    std::vector<double> results; // ms
+    results.reserve(num_iters);
+
+    for (size_t i = 0; i < num_iters; ++i) {
+        acGridSynchronizeStream(STREAM_ALL);
+        timer_reset(&t);
+        acGridSynchronizeStream(STREAM_ALL);
+        acGridIntegrate(STREAM_DEFAULT, dt);
+        acGridSynchronizeStream(STREAM_ALL);
+        results.push_back(timer_diff_nsec(t) / 1e6);
+    }
+
+    std::sort(results.begin(), results.end(),
+              [](const double& a, const double& b) { return a < b; });
+    fprintf(stdout,
+            "Integration step time %g ms (%gth percentile)--------------------------------------\n",
+            results[nth_percentile * num_iters], 100 * nth_percentile);
+    acGridSynchronizeStream(STREAM_ALL);
+
+    acGridQuit();
+    MPI_Finalize();
+    return EXIT_SUCCESS;
+}
+
+#else
+int
+main(void)
+{
+    printf("The library was built without MPI support, cannot run mpitest. Rebuild Astaroth with "
+           "cmake -DMPI_ENABLED=ON .. to enable.\n");
+    return EXIT_FAILURE;
+}
+#endif // AC_MPI_ENABLES