implemented use of iterations for longer tests

libiotrace/test/MPI_parallel_IO_Posix.c

@@ -1,30 +1,59 @@
 /** Example in which every process writes its own data
  *  via POSIX I/O **/
 
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include "omp.h"
+
 #include "mpi.h"
 #include <stdio.h>
 #define BUFSIZE 100
 
+void usage (void) {
+    printf("USAGE: mpirun mpi_file_io [ITERATIONS]\n");
+    printf(" \n");
+    printf("Runs MPI File I/O tests on mpi_file_io. If the optional ITERATIONS\n");
+    printf("is not specified, this will indefinitely write into file mpi_fil_io.txt\n");
+    printf("filling up Your file-system.\n");
+    exit(EXIT_FAILURE);
+}
+
 int main(int argc, char *argv[]){
+    int max_iterations = INT_MAX; // Iterate indefinitely
+
+    if (argc > 1) {
+        char * endptr;
+        max_iterations = strtol(argv[1], &endptr, 10);
+        if (*endptr != '\0' || max_iterations < 0)
+            usage();
+    }
 
-    int i, rank, buf[BUFSIZE];
-    char filename[128];
-    FILE *file;
+    for (int j = 0; j < max_iterations; j++) {
+        int i, rank, buf[BUFSIZE];
+        char filename[128];
+        FILE *file;
 
-    MPI_Init(&argc, &argv);
+        MPI_Init(&argc, &argv);
 
-    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+        MPI_Comm_rank(MPI_COMM_WORLD, &rank);
 
-    for (i=0; i<BUFSIZE; i++){
-        buf[i] = rank * BUFSIZE + i;
-    }
+        for (i=0; i<BUFSIZE; i++){
+            buf[i] = rank * BUFSIZE + i;
+        }
 
-    sprintf(filename, "testfile.%d", rank);
-    file = fopen(filename, "w");
-    fwrite(buf, sizeof(int), BUFSIZE, file);
-    fclose(file);
+        sprintf(filename, "testfile.%d", rank);
+        file = fopen(filename, "w");
+        fwrite(buf, sizeof(int), BUFSIZE, file);
+        fclose(file);
 
-    MPI_Finalize();
-
-    return 0;
-}
+        MPI_Finalize();
+
+        return 0;
+    }
+}