/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

/* tests whether atomicity semantics are satisfied for overlapping accesses

   in atomic mode. The probability of detecting errors is higher if you run

   it on 8 or more processes. */

/* The file name is taken as a command-line argument. */

static void handle_error(int errcode, const char *str)

{

    char msg[MPI_MAX_ERROR_STRING];

    int resultlen;

    MPI_Error_string(errcode, msg, &resultlen);

    fprintf(stderr, "%s: %s\n", str, msg);

    MPI_Abort(MPI_COMM_WORLD, 1);

}

#define MPI_CHECK(fn) { int errcode; errcode = (fn); if (errcode != MPI_SUCCESS) handle_error(errcode, #fn); }

#define BUFSIZE 10000   /* no. of integers */

#define VERBOSE 0

int main(int argc, char **argv)

{

    int *writebuf, *readbuf, i, mynod, nprocs, len, err;

    char *filename;

    int errs = 0, toterrs;

    MPI_Datatype newtype;

    MPI_File fh;

    MPI_Status status;

    MPI_Info info;

    MPI_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &mynod);

    MPI_Comm_size(MPI_COMM_WORLD, &nprocs);

/* process 0 takes the file name as a command-line argument and

   broadcasts it to other processes */

    if (!mynod) {

        i = 1;

        while ((i < argc) && strcmp("-fname", *argv)) {

            i++;

            argv++;

        }

        if (i >= argc) {

            fprintf(stderr, "\n*#  Usage: coll_test -fname filename\n\n");

            MPI_Abort(MPI_COMM_WORLD, 1);

        }

        argv++;

        len = strlen(*argv);

        filename = (char *) malloc(len + 1);

        strcpy(filename, *argv);

        MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);

        MPI_Bcast(filename, len + 1, MPI_CHAR, 0, MPI_COMM_WORLD);

    } else {

        MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);

        filename = (char *) malloc(len + 1);

        MPI_Bcast(filename, len + 1, MPI_CHAR, 0, MPI_COMM_WORLD);

    }

    writebuf = (int *) malloc(BUFSIZE * sizeof(int));

    readbuf = (int *) malloc(BUFSIZE * sizeof(int));

/* test atomicity of contiguous accesses */

/* initialize file to all zeros */

    if (!mynod) {

        /* ignore error: file may or may not exist */

        MPI_File_delete(filename, MPI_INFO_NULL);

        MPI_CHECK(MPI_File_open(MPI_COMM_SELF, filename,

                                MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));

        for (i = 0; i < BUFSIZE; i++)

            writebuf[i] = 0;

        MPI_CHECK(MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status));

        MPI_CHECK(MPI_File_close(&fh));

#if VERBOSE

        fprintf(stderr, "\ntesting contiguous accesses\n");

#endif

    }

    MPI_Barrier(MPI_COMM_WORLD);

    for (i = 0; i < BUFSIZE; i++)

        writebuf[i] = 10;

    for (i = 0; i < BUFSIZE; i++)

        readbuf[i] = 20;

    MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename,

                            MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));

/* set atomicity to true */

    err = MPI_File_set_atomicity(fh, 1);

    if (err != MPI_SUCCESS) {

        fprintf(stderr, "Atomic mode not supported on this file system.\n");

        fflush(stderr);

        errs++;

        goto fn_exit;

    }

    MPI_Barrier(MPI_COMM_WORLD);

/* process 0 writes and others concurrently read. In atomic mode,

   the data read must be either all old values or all new values; nothing

   in between. */

    if (!mynod) {

        MPI_CHECK(MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status));

    } else {

        err = MPI_File_read(fh, readbuf, BUFSIZE, MPI_INT, &status);

        if (err == MPI_SUCCESS) {

            if (readbuf[0] == 0) {      /* the rest must also be 0 */

                for (i = 1; i < BUFSIZE; i++)

                    if (readbuf[i] != 0) {

                        errs++;

                        fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 0\n", mynod, i,

                                readbuf[i]);

                        goto fn_exit;

                    }

            } else if (readbuf[0] == 10) {      /* the rest must also be 10 */

                for (i = 1; i < BUFSIZE; i++)

                    if (readbuf[i] != 10) {

                        errs++;

                        fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 10\n", mynod, i,

                                readbuf[i]);

                        goto fn_exit;

                    }

            } else {

                errs++;

                fprintf(stderr, "Process %d: readbuf[0] is %d, should be either 0 or 10\n", mynod,

                        readbuf[0]);

            }

        }

    }

    MPI_CHECK(MPI_File_close(&fh));

    MPI_Barrier(MPI_COMM_WORLD);

/* repeat the same test with a noncontiguous filetype */

    MPI_Type_vector(BUFSIZE, 1, 2, MPI_INT, &newtype);

    MPI_Type_commit(&newtype);

    MPI_Info_create(&info;;

    /* I am setting these info values for testing purposes only. It is

     * better to use the default values in practice. */

    MPI_Info_set(info, "ind_rd_buffer_size", "1209");

    MPI_Info_set(info, "ind_wr_buffer_size", "1107");

    if (!mynod) {

        MPI_CHECK(MPI_File_delete(filename, MPI_INFO_NULL));

        MPI_CHECK(MPI_File_open(MPI_COMM_SELF, filename,

                                MPI_MODE_CREATE | MPI_MODE_RDWR, info, &fh));

        for (i = 0; i < BUFSIZE; i++)

            writebuf[i] = 0;

        MPI_CHECK(MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", info));

        MPI_CHECK(MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status));

        MPI_File_close(&fh;;

#if VERBOSE

        fprintf(stderr, "\ntesting noncontiguous accesses\n");

#endif

    }

    MPI_Barrier(MPI_COMM_WORLD);

    for (i = 0; i < BUFSIZE; i++)

        writebuf[i] = 10;

    for (i = 0; i < BUFSIZE; i++)

        readbuf[i] = 20;

    MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE | MPI_MODE_RDWR, info, &fh));

    MPI_CHECK(MPI_File_set_atomicity(fh, 1));

    MPI_CHECK(MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", info));

    MPI_Barrier(MPI_COMM_WORLD);

    if (!mynod) {

        MPI_CHECK(MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status));

    } else {

        err = MPI_File_read(fh, readbuf, BUFSIZE, MPI_INT, &status);

        if (err == MPI_SUCCESS) {

            if (readbuf[0] == 0) {

                for (i = 1; i < BUFSIZE; i++)

                    if (readbuf[i] != 0) {

                        errs++;

                        fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 0\n", mynod, i,

                                readbuf[i]);

                        goto fn_exit;

                    }

            } else if (readbuf[0] == 10) {

                for (i = 1; i < BUFSIZE; i++)

                    if (readbuf[i] != 10) {

                        errs++;

                        fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 10\n", mynod, i,

                                readbuf[i]);

                        goto fn_exit;

                    }

            } else {

                errs++;

                fprintf(stderr, "Process %d: readbuf[0] is %d, should be either 0 or 10\n", mynod,

                        readbuf[0]);

            }

        }

    }

    MPI_Type_free(&newtype);

    MPI_Info_free(&info;;

  fn_exit:

    MPI_File_close(&fh;;

    MPI_Barrier(MPI_COMM_WORLD);

    MPI_Allreduce(&errs, &toterrs, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD);

    if (mynod == 0) {

        if (toterrs > 0) {

            fprintf(stderr, "Found %d errors\n", toterrs);

        } else {

            fprintf(stdout, " No Errors\n");

        }

    }

    free(writebuf);

    free(readbuf);

    free(filename);

    MPI_Finalize();

    return 0;

}