/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright  2008 Sun Microsystems, Inc. All rights reserved
 * Use is subject to license terms.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/tests/write_append_truncate.c
 *
 * Each loop does 3 things:
 *   - truncate file to zero (not via ftruncate though, to test O_APPEND)
 *   - write a "chunk" of data (should be at file offset 0 after truncate)
 *   - on each of two threads either append or truncate-up the file
 *
 * If the truncate happened first, we should have a hole in the file.
 * If the append happened first, we should have truncated the file down.
 *
 * WRITE_SIZE_MAX and APPEND_SIZE_MAX are large enough to cross a stripe.
 *
 * compile: mpicc -g -Wall -o write_append_truncate write_append_truncate.c
 * run:     mpirun -np 2 -machlist <hostlist file> write_append_truncate <file>
 *  or:     pdsh -w <two hosts> write_append_truncate <file>
 *  or:     prun -n 2 [-N 2] write_append_truncate <file>
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include "mpi.h"

#define DEFAULT_ITER    10000

#define WRITE_SIZE_MAX  1234567
#define APPEND_SIZE_MAX 1234567
#define TRUNC_SIZE_MAX  1234567

#define STATUS_FMT "WR %c %7d/%#08x, AP %c %7d/%#08x, TR@ %7d/%#08x"

#define HOSTNAME_SIZE 50
char hostname[HOSTNAME_SIZE];
#define FNAMES_MAX 256

void usage(char *prog)
{
        printf("usage: %s [-a append_max] [-C] [-n nloops] [-s seed]\n"
               "\t\t[-t trunc_max] [-T] [-v] [-w write_max] <filename> ...\n", prog);
        printf("\t-a append_max: maximum size of append, default %u bytes\n",
               APPEND_SIZE_MAX);
        printf("\t-C: 'classic' checks (on file 0)\n");
        printf("\t-n nloops: count of loops to run, default %u\n",DEFAULT_ITER);
        printf("\t-s seed: random seed to use, default {current time}\n");
        printf("\t-t trunc_max: maximum size of truncate, default %u bytes\n",
               TRUNC_SIZE_MAX);
        printf("\t-T: 'classic' truncates (on file 0)\n");
        printf("\t-w write_max: maximum size of write, default %u bytes\n",
               WRITE_SIZE_MAX);
        printf("\t-W: 'classic' writes (on rank 0, file 0)\n");
        printf("\t-v: run in verbose mode (repeat for more verbosity)\n");
        printf("\tfilename for each mountpoint of same filesystem on a node\n");
        printf("\b%s must be run with at least 2 processes\n", prog);

        MPI_Finalize();
        exit(1);
}

/* Print process rank, loop count, message, and exit (i.e. a fatal error) */
void rprintf(int rank, int loop, int error, const char *fmt, ...)
__attribute__ ((format (printf, 4, 5)));

void rprintf(int rank, int loop, int error, const char *fmt, ...)
{
        va_list       ap;

        printf("r=%2u", rank);
        if (loop >= 0)
                printf(" l=%04u", loop);
        if (error != 0)
                printf(" %s", hostname);
        printf(": ");

        va_start(ap, fmt);

        vprintf(fmt, ap);

        if (error != 0)
                MPI_Abort(MPI_COMM_WORLD, error);
}

int main(int argc, char *argv[])
{
        int n, nloops = DEFAULT_ITER;
        int nfnames = 0, ifnames, fd;
        int rank = -1, nproc, ret;
        unsigned write_max = WRITE_SIZE_MAX;
        unsigned append_max = APPEND_SIZE_MAX;
        unsigned write_size = 0, append_size = 0, trunc_size = 0;
        unsigned trunc_max = 0, trunc_offset = 0;
        char *append_buf;
        char *write_buf;
        char *read_buf = NULL;
        char *trunc_buf = NULL;
        int seed = time(0);
        int done;
        int error;
        int verbose = 0;
        int classic_check = 0, classic_trunc = 0, classic_write = 0;
        char write_char = 'A', append_char = 'a';
        char *fnames[FNAMES_MAX], *end;
        char *prog = "write_append_truncate";
        int c;

        error = MPI_Init(&argc, &argv);
        if (error != MPI_SUCCESS)
                printf("%s: MPI_Init failed: %d\n", prog, error);
        else if (verbose > 2)
                printf("%s: MPI_Init succeeded\n", prog);

        prog = strrchr(argv[0], '/');
        if (prog == NULL)
                prog = argv[0];
        else
                prog++;

        while ((c = getopt(argc, argv, "a:cCn:s:t:Tvw:W")) != -1) {
                switch(c) {
                case 'a':
                        append_max = strtoul(optarg, &end, 0);
                        if (append_max == 0 || *end) {
                                fprintf(stderr, "%s: bad append option '%s'\n",
                                        prog, optarg);
                                usage(prog);
                        }
                        break;
                case 'C':
                        classic_check++;
                        break;
                case 'n':
                        nloops = strtoul(optarg, &end, 0);
                        if (nloops == 0 || *end) {
                                fprintf(stderr, "%s: bad nloops option '%s'\n",
                                        prog, optarg);
                                usage(prog);
                        }
                        break;
                case 's':
                        seed = strtoul(optarg, &end, 0);
                        if (*end) {
                                fprintf(stderr, "%s: bad seed option '%s'\n",
                                        prog, optarg);
                                usage(prog);
                        }
                        break;
                case 't':
                        trunc_max = strtoul(optarg, &end, 0);
                        if (*end) {
                                fprintf(stderr,"%s: bad truncate option '%s'\n",
                                        prog, optarg);
                                usage(prog);
                        }
                        break;
                case 'T':
                        classic_trunc++;
                        break;
                case 'v':
                        verbose++;
                        break;
                case 'w':
                        write_max = strtoul(optarg, &end, 0);
                        if (write_max == 0 || *end) {
                                fprintf(stderr, "%s: bad write option '%s'\n",
                                        prog, optarg);
                                usage(prog);
                        }
                        break;
                case 'W':
                        classic_write++;
                        break;
                default:
                        fprintf(stderr, "%s: unknown option '%c'\n", prog, c);
                        usage(prog);
                }
        }

        srand(seed);

        if (argc == optind) {
                fprintf(stderr, "%s: missing filename argument\n", prog);
                usage(prog);
        }

        if (argc > optind + FNAMES_MAX) {
                fprintf(stderr, "%s: too many extra options\n", prog);
                usage(prog);
        }

        while (optind < argc)
                fnames[nfnames++] = argv[optind++];

        error = MPI_Comm_rank(MPI_COMM_WORLD, &rank);
        if (verbose > 2 || error != MPI_SUCCESS)
                rprintf(rank, -1, error != MPI_SUCCESS, "MPI_Comm_rank: %d\n",
                        error);

        error = MPI_Comm_size(MPI_COMM_WORLD, &nproc);
        if (verbose > 2 || error != MPI_SUCCESS)
                rprintf(rank, -1, error != MPI_SUCCESS, "MPI_Comm_size: %d\n",
                        error);

        if (nproc < 2)
                rprintf(rank, -1, 1, "%s: must run with at least 2 processes\n",
                        prog);

        append_buf = malloc(append_max);
        if (append_buf == NULL)
                rprintf(rank, -1, 1,"%s: error allocating append_buf %u\n",
                        prog, append_max);

        write_buf = malloc(write_max);
        if (write_buf == NULL)
                rprintf(rank, -1, 1, "%s: error allocating write_buf %u\n",
                        prog, write_max);

        if (gethostname(hostname, HOSTNAME_SIZE) < 0)
                rprintf(rank, -1, 1, "%s: gethostname failed: %s\n",
                        prog, strerror(errno));

        if (rank == 0) {
                int max_size = write_max + (trunc_max ?: append_max)+append_max;

                fd = open(fnames[0], O_WRONLY|O_CREAT|O_TRUNC, 0666);
                rprintf(rank,-1, fd<0, "create %s, max size: %u, seed %u: %s\n",
                        fnames[0], max_size, seed, strerror(errno));
                close(fd);

                trunc_buf = calloc(1, trunc_max ?: append_max);
                if (trunc_buf == NULL)
                        rprintf(rank,-1,1,"%s: error allocating trunc_buf %u\n",
                                prog, trunc_max ?: append_max);

                /* initial write + truncate up + append */
                read_buf = malloc(max_size);
                if (read_buf == NULL)
                        rprintf(rank,-1,1,"%s: error allocating read_buf %u\n",
                                prog, max_size);
        }

        error = MPI_Barrier(MPI_COMM_WORLD);
        if (verbose > 2 || error != MPI_SUCCESS)
                rprintf(rank, -1, error != MPI_SUCCESS,
                        "prep MPI_Barrier: %d\n", error);

        ifnames = rank % nfnames;
        fd = open(fnames[ifnames], O_RDWR | O_APPEND);
        if (verbose || fd < 0)
                rprintf(rank, -1, errno, "open '%s' (%u): %s\n",
                        fnames[ifnames], ifnames, strerror(errno));

        for (n = 0; n < nloops; n++) {
                /* Initialized only to quiet stupid GCC warnings */
                unsigned write_rank = 0, append_rank = n, trunc_rank = n + 1;
                unsigned mpi_shared_vars[6];

                /* reset the environment */
                write_char = 'A' + (n % 26);
                append_char = 'a' + (n % 26);

                if (rank == 0) {
                        write_size = (rand() % (write_max - 1)) + 1;
                        append_size = (rand() % (append_max - 1)) + 1;
                        trunc_size = (rand() % ((trunc_max?: append_size)-1))+1;
                        trunc_offset = write_size + trunc_size;

                        if (verbose || n % 1000 == 0)
                                rprintf(rank, n, 0, STATUS_FMT"\n",
                                        write_char, write_size, write_size,
                                        append_char, append_size, append_size,
                                        trunc_offset, trunc_offset);

                        write_rank = (classic_write ? 0 : rand()) % nproc;
                        do {
                                append_rank = (classic_write ? n : rand()) %
                                                                nproc;
                                /* We can't allow the append rank be the same
                                 * as the classic_trunc trunc_rank, or we will
                                 * spin here forever. */
                        } while (append_rank == (n + 1) % nproc);
                        do {
                                trunc_rank = (classic_trunc? (n + 1) : rand()) %
                                                                nproc;
                        } while (trunc_rank == append_rank);

                        mpi_shared_vars[0] = write_size;
                        mpi_shared_vars[1] = append_size;
                        mpi_shared_vars[2] = trunc_size;
                        mpi_shared_vars[3] = write_rank;
                        mpi_shared_vars[4] = append_rank;
                        mpi_shared_vars[5] = trunc_rank;
                }

                error = MPI_Bcast(&mpi_shared_vars, 6,
                                  MPI_INT, 0, MPI_COMM_WORLD);
                if (verbose > 2 || error != MPI_SUCCESS)
                        rprintf(rank, n, error != MPI_SUCCESS,
                                "MPI_Bcast mpi_shared_vars"
                                "[%u, %u, %u, %u, %u, %u]: %d\n",
                                mpi_shared_vars[0], mpi_shared_vars[1],
                                mpi_shared_vars[2], mpi_shared_vars[3],
                                mpi_shared_vars[4], mpi_shared_vars[5], error);

                if (rank != 0) {
                        write_size  = mpi_shared_vars[0];
                        append_size = mpi_shared_vars[1];
                        trunc_size  = mpi_shared_vars[2];
                        write_rank  = mpi_shared_vars[3];
                        append_rank = mpi_shared_vars[4];
                        trunc_rank  = mpi_shared_vars[5];

                        trunc_offset = write_size + trunc_size;
                }

                if (rank == write_rank || rank == 0)
                        memset(write_buf, write_char, write_max);

                if (rank == write_rank) {
                        ifnames = (classic_write ? 0 : rand()) % nfnames;
                        ret = truncate(fnames[ifnames], 0);
                        if (verbose > 1 || ret != 0)
                                rprintf(rank, n, ret,
                                        "initial truncate %s (%u) @ 0: %s\n",
                                        fnames[ifnames], ifnames,
                                        strerror(errno));

                        done = 0;
                        do {
                                ret = write(fd, write_buf+done,write_size-done);
                                if (verbose > 1 || ret <= 0) {
                                        rprintf(rank, n, ret <= 0,
                                                "write %d/%d @ %d: %s\n",
                                                ret + done, write_size, done,
                                                strerror(errno));
                                        if (ret <= 0)
                                                break;
                                }
                                done += ret;
                        } while (done != write_size);
                }

                if (rank == append_rank || rank == 0)
                        memset(append_buf, append_char, append_size);

                error = MPI_Barrier(MPI_COMM_WORLD);
                if (verbose > 2 || error != MPI_SUCCESS)
                        rprintf(rank, n, error != MPI_SUCCESS,
                                "start MPI_Barrier: %d\n", error);

                /* Do the race */
                if (rank == append_rank) {
                        done = 0;
                        do {
                                ret = write(fd, append_buf + done,
                                            append_size - done);
                                if (ret < 0) {
                                        rprintf(rank, n, ret < 0,
                                                "append %u/%u: %s\n",
                                                ret + done, append_size,
                                                strerror(errno));
                                        break;
                                } else if (verbose > 1 || ret != append_size) {
                                        rprintf(rank, n, ret != append_size,
                                                "append %u/%u\n",
                                                ret + done, append_size);
                                }
                                done += ret;
                        } while (done != append_size);
                } else if (rank == trunc_rank) {
                        /* XXX: truncating the same file descriptor as the
                         *      append on a single node causes this test
                         *      to fail currently (2009-02-01). */
                        ifnames = (classic_trunc ? rank : rand()) % nfnames;
                        ret = truncate(fnames[ifnames], trunc_offset);
                        if (verbose > 1 || ret != 0)
                                rprintf(rank, n, ret,
                                        "truncate %s (%u) @ %u: %s\n",
                                        fnames[ifnames], ifnames,
                                        trunc_offset, strerror(errno));
                }

                error = MPI_Barrier(MPI_COMM_WORLD);
                if (verbose > 2 || error != MPI_SUCCESS)
                        rprintf(rank, n, error != MPI_SUCCESS,
                                "end MPI_Barrier: %d\n", error);

                error = 0;

                /* Check the result */
                if (rank == 0) {
                        char *tmp_buf;
                        struct stat st = { 0 };

                        ifnames = classic_check ? 0 : (rand() % nfnames);
                        ret = stat(fnames[ifnames], &st);
                        if (verbose > 1 || ret != 0)
                                rprintf(rank, n, ret,
                                        "stat %s (%u) size %llu: %s\n",
                                        fnames[ifnames], ifnames,
                                        (long long)st.st_size, strerror(errno));

                        ret = lseek(fd, 0, SEEK_SET);
                        if (ret != 0)
                                rprintf(rank, n, ret, "lseek 0: %s\n",
                                        strerror(errno));

                        done = 0;
                        do {
                                ret = read(fd, read_buf+done, st.st_size-done);
                                if (verbose > 1 || ret <= 0) {
                                        rprintf(rank, n, ret <= 0,
                                                "read %d/%llu @ %u: %s\n",
                                                ret, (long long)st.st_size-done,
                                                done, ret != 0 ?
                                                strerror(errno) : "short read");
                                }
                                done += ret;
                        } while (done != st.st_size);

                        if (memcmp(read_buf, write_buf, write_size)) {
                                rprintf(rank, n, 0, "WRITE bad "
                                        "[0-%d]/[0-%#x] != %c\n",
                                        write_size - 1, write_size - 1,
                                        write_char);
                                error = 1;
                        }

                        tmp_buf = read_buf + write_size;

                        if (st.st_size == trunc_offset) {
                                /* Check case 1: first append then truncate */
                                int tmp_size, tmp_offset;

                                tmp_size = trunc_size < append_size ?
                                                trunc_size : append_size;
                                tmp_offset = write_size + tmp_size;

                                if (memcmp(tmp_buf, append_buf, tmp_size)) {
                                        rprintf(rank, n, 0,"trunc-after-APPEND "
                                                "bad [%d-%d]/[%#x-%#x] != %c\n",
                                                write_size, tmp_offset - 1,
                                                write_size, tmp_offset - 1,
                                                append_char);
                                        error = 1;
                                } else if (trunc_size > append_size &&
                                           memcmp(tmp_buf+append_size,trunc_buf,
                                                  trunc_size - append_size)) {
                                        rprintf(rank, n, 0,"TRUNC-after-append "
                                                "bad [%d-%d]/[%#x-%#x] != 0\n",
                                                tmp_offset, trunc_offset - 1,
                                                tmp_offset, trunc_offset - 1);
                                        error = 1;
                                }
                        } else {
                                int expected_size = trunc_offset + append_size;
                                /* Check case 2: first truncate then append */
                                if (st.st_size != expected_size) {
                                        rprintf(rank, n, 0,"APPEND-after-trunc "
                                                "bad file size %llu != %u\n",
                                                (long long)st.st_size,
                                                expected_size);
                                        error = 1;
                                }

                                if (memcmp(tmp_buf, trunc_buf, trunc_size)) {
                                        rprintf(rank, n, 0,"append-after-TRUNC "
                                                "bad [%d-%d]/[%#x-%#x] != 0\n",
                                                write_size, trunc_offset - 1,
                                                write_size, trunc_offset - 1);
                                        error = 1;
                                } else if (memcmp(read_buf + trunc_offset,
                                                  append_buf, append_size)) {
                                        rprintf(rank, n, 0,"APPEND-after-trunc "
                                                "bad [%d-%d]/[%#x-%#x] != %c\n",
                                                trunc_offset, expected_size - 1,
                                                trunc_offset, expected_size - 1,
                                                append_char);
                                        error = 1;
                                }
                        }

                        if (error == 1) {
                                char command[4096];
                                int rc;

                                rprintf(rank, n, 0, STATUS_FMT"\n",
                                        write_char, write_size, write_size,
                                        append_char, append_size, append_size,
                                        trunc_offset, trunc_offset);

                                sprintf(command, "od -Ax -a %s", fnames[0]);
                                rc = system(command);
                                MPI_Abort(MPI_COMM_WORLD, 1);
                        }
                }
        }

        if (rank == 0 || verbose)
                printf("r=%2u n=%4u: "STATUS_FMT"\nPASS\n", rank, n - 1,
                       write_char, write_size, write_size,
                       append_char, append_size, append_size,
                       trunc_offset, trunc_offset);

        close(fd);

        if (rank == 0) {
                ifnames = rand() % nfnames;
                ret = unlink(fnames[ifnames]);
                if (ret != 0)
                        printf("%s: unlink %s failed: %s\n",
                               prog, fnames[ifnames], strerror(errno));
        }

        MPI_Finalize();
        return 0;
}