test.cpp

/**
 * @file test.cpp
 *
 * SPDX-FileCopyrightText: 2008-2026 HPCS Group <rootsim@googlegroups.com>
 * SPDX-License-Identifier: GPL-3.0-only
 *
 * @brief A test file for CPP
 */
#include <cstdlib>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <mpi.h>

using namespace std;

/**
 * @brief Print the current time
 */
void timestamp()
{
#define TIME_SIZE 40

	static char time_buffer[TIME_SIZE];
	const struct std::tm *tm_ptr;
	std::time_t now;

	now = std::time(NULL);
	tm_ptr = std::localtime(&now);

	std::strftime(time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr);

	std::cout << time_buffer << "\n";

	return;
#undef TIME_SIZE
}

/**
 * @brief the @c main function.
 *
 * This is the entry point of the program, and the only function in this dummy test.
 *
 * @param argc the number of arguments
 * @param argv the vector of arguments
 *
 * @return the exit code
 */
int main(int argc, char *argv[])
{
	int id;
	int ierr;
	int p;
	double wtime;

	ierr = MPI_Init(&argc, &argv);

	if(ierr != 0) {
		cout << "\n";
		cout << "HELLO_MPI - Fatal error!\n";
		cout << "  MPI_Init returned nonzero ierr.\n";
		exit(1);
	}
	ierr = MPI_Comm_size(MPI_COMM_WORLD, &p);
	ierr = MPI_Comm_rank(MPI_COMM_WORLD, &id);
	if(id == 0) {
		timestamp();
		cout << "\n";
		cout << "P" << id << ":  HELLO_MPI - Master process:\n";
		cout << "P" << id << ":    C++/MPI version\n";
		cout << "P" << id << ":    An MPI example program.\n";
		cout << "\n";
		cout << "P" << id << ":    The number of processes is " << p << "\n";
		cout << "\n";
	}
	if(id == 0) {
		wtime = MPI_Wtime();
	}
	cout << "P" << id << ":    'Hello, world!'\n";
	if(id == 0) {
		wtime = MPI_Wtime() - wtime;
		cout << "P" << id << ":    Elapsed wall clock time = " << wtime << " seconds.\n";
	}

	MPI_Finalize();

	if(id == 0) {
		cout << "\n";
		cout << "P" << id << ":  HELLO_MPI:\n";
		cout << "P" << id << ":    Normal end of execution.\n";
		cout << "\n";
		timestamp();
	}
	return 0;
}