path: root/test/mirror_vfd.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * Purpose: Test the Mirror VFD functionality.
 */

/* WARNING: The use of realpath() is probably system-dependent, as are
 * other things here such as the socket calls.
 * Notable to realpath() in particular is the use of "PATH_MAX", which
 * apparently has some major potential issues if paths are abused.
 * http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
 * so BE CAREFUL about the paths we throw around?
 */

#include "h5test.h"
#include "cache_common.h"
#include "genall5.h"

#ifdef H5_HAVE_MIRROR_VFD

#include "H5FDmirror_priv.h" /* Private header for the mirror VFD */

/* For future consideration, IP address and port number might be
 * environment variables?
 */
#define SERVER_IP_ADDRESS "127.0.0.1"

/* Primary listening port on server. */
#define SERVER_HANDSHAKE_PORT 3000

#define DATABUFFER_SIZE 128
#define DSET_NAME_LEN   16

/* Parameters for the "large chunked dataset" writing */
#define MAX_DSET_COUNT 255
#define DSET_DIM       32
#define CHUNK_DIM      8

#define CONCURRENT_COUNT 3 /* Number of files in concurrent test */

/* Macro: LOGPRINT()
 * Prints logging and debugging messages to the output stream based
 * on the level of verbosity.
 *     0 : no logging
 *     1 : errors only
 *     2 : details
 *     3 : all
 */
#define DEFAULT_VERBOSITY 1
static unsigned int g_verbosity = DEFAULT_VERBOSITY;

/* Macro for selective debug printing / logging */
#define LOGPRINT(lvl, ...)                                                                                   \
    do {                                                                                                     \
        if ((lvl) <= g_verbosity) {                                                                          \
            fprintf(g_log_stream, __VA_ARGS__);                                                              \
            fflush(g_log_stream);                                                                            \
        }                                                                                                    \
    } while (0)

#define MIRROR_RW_DIR "mirror_rw/"
#define MIRROR_WO_DIR "mirror_wo/"

/* String buffer for error messages */
#define MIRR_MESG_SIZE 128
static char mesg[MIRR_MESG_SIZE + 1];

/* ----------------------------------------------------------------------------
 * Structure:   struct mt_opts
 *
 * Purpose:     Convenience structure to hold options as parsed from the
 *              command line.
 *
 * `portno` (int)
 *      Port number, as received from arguments.
 *
 * `ip` (char *)
 *      IP address string as received from arguments.
 *
 * ----------------------------------------------------------------------------
 */
struct mt_opts {
    int  portno;
    char ip[H5FD_MIRROR_MAX_IP_LEN + 1];
};

/* Convenience structure for passing file names via helper functions.
 */
struct mirrortest_filenames {
    char rw[H5FD_SPLITTER_PATH_MAX + 1];
    char wo[H5FD_SPLITTER_PATH_MAX + 1];
    char log[H5FD_SPLITTER_PATH_MAX + 1];
};

static FILE *g_log_stream = NULL; /* initialized at runtime */

static herr_t _verify_datasets(unsigned min_dset, unsigned max_dset, hid_t *filespace_id, hid_t *dataset_id,
                               hid_t memspace_id);

static herr_t _create_chunking_ids(hid_t file_id, unsigned min_dset, unsigned max_dset, hsize_t *chunk_dims,
                                   hsize_t *dset_dims, hid_t *dataspace_ids, hid_t *filespace_ids,
                                   hid_t *dataset_ids, hid_t *memspace_id);

static herr_t _close_chunking_ids(unsigned min_dset, unsigned max_dset, hid_t *dataspace_ids,
                                  hid_t *filespace_ids, hid_t *dataset_ids, hid_t *memspace_id);

static herr_t populate_filepath(const char *dirname, const char *_basename, hid_t fapl_id, char *path_out,
                                bool h5suffix);

static hid_t create_mirroring_split_fapl(const char *_basename, struct mirrortest_filenames *names,
                                         const struct mt_opts *opts);

/* ----------------------------------------------------------------------------
 * Function:   populate_filepath
 *
 * Purpose:    Given a directory name and a base name, concatenate the two and
 *             run h5fixname() to get the "actual" path to the intended target.
 *             `h5suffix' should be false to keep the base name unaltered;
 *             true will append the '.h5' h5suffix to the basename...
 *             false -> h5fixname_no_suffix(), true -> h5fixname()
 *             <h5fixname_prefix> / <dirname> / <basename> <h5prefix?>
 *
 * ----------------------------------------------------------------------------
 */
static herr_t
populate_filepath(const char *dirname, const char *basename, hid_t fapl_id, char *path_out, bool h5suffix)
{
    char *path = NULL;

    if ((basename == NULL) || (*basename == 0) || (dirname == NULL) || (*dirname == 0) || (path_out == NULL))
        TEST_ERROR;

    if (NULL == (path = calloc(H5FD_SPLITTER_PATH_MAX, sizeof(char))))
        TEST_ERROR;

    if (snprintf(path, H5FD_SPLITTER_PATH_MAX, "%s%s%s", dirname,
                 (dirname[strlen(dirname)] == '/') ? "" : "/", /* slash iff needed */
                 basename) > H5FD_SPLITTER_PATH_MAX)
        TEST_ERROR;

    if (h5suffix == true) {
        if (h5_fixname(path, fapl_id, path_out, H5FD_SPLITTER_PATH_MAX) == NULL)
            TEST_ERROR;
    }
    else {
        if (h5_fixname_no_suffix(path, fapl_id, path_out, H5FD_SPLITTER_PATH_MAX) == NULL)
            TEST_ERROR;
    }

    free(path);

    return SUCCEED;

error:
    free(path);
    return FAIL;
} /* end populate_filepath() */

/* ---------------------------------------------------------------------------
 * Function:    build_paths
 *
 * Purpose:     Convenience function to create the three file paths used in
 *              most mirror tests.
 *
 * Return:      SUCCEED/FAIL
 * ---------------------------------------------------------------------------
 */
static herr_t
build_paths(const char *basename, H5FD_splitter_vfd_config_t *splitter_config,
            struct mirrortest_filenames *names)
{
    char *baselogname = NULL;

    if (NULL == (baselogname = calloc(H5FD_SPLITTER_PATH_MAX, sizeof(char))))
        TEST_ERROR;

    if (populate_filepath(MIRROR_RW_DIR, basename, splitter_config->rw_fapl_id, names->rw, true) < 0)
        TEST_ERROR;

    if (populate_filepath(MIRROR_WO_DIR, basename, splitter_config->wo_fapl_id, names->wo, true) < 0)
        TEST_ERROR;

    if (basename == NULL || *basename == 0)
        TEST_ERROR;
    if (snprintf(baselogname, H5FD_SPLITTER_PATH_MAX, "%s_err.log", basename) > H5FD_SPLITTER_PATH_MAX)
        TEST_ERROR;

    if (populate_filepath(MIRROR_WO_DIR, baselogname, splitter_config->wo_fapl_id, names->log, false) < 0)
        TEST_ERROR;

    free(baselogname);

    return SUCCEED;

error:
    free(baselogname);
    return FAIL;
} /* end build_paths() */

/* ---------------------------------------------------------------------------
 * Function:    test_fapl_configuration
 *
 * Purpose:     Test FAPL configuration and examination.
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_fapl_configuration(void)
{
    hid_t              fapl_id     = H5I_INVALID_HID;
    H5FD_mirror_fapl_t mirror_conf = {
        H5FD_MIRROR_FAPL_MAGIC,          /* magic */
        H5FD_MIRROR_CURR_FAPL_T_VERSION, /* version */
        SERVER_HANDSHAKE_PORT,           /* handhake_port */
        SERVER_IP_ADDRESS,               /* remote_ip "IP address" */
    };
    H5FD_mirror_fapl_t fa_out = {0, 0, 0, ""};

    TESTING("Mirror fapl configuration (set/get)");

    if ((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
        TEST_ERROR;

    if (H5Pset_fapl_mirror(fapl_id, &mirror_conf) < 0)
        TEST_ERROR;

    if (H5Pget_fapl_mirror(fapl_id, &fa_out) < 0)
        TEST_ERROR;

    if (H5FD_MIRROR_FAPL_MAGIC != fa_out.magic)
        TEST_ERROR;

    if (H5FD_MIRROR_CURR_FAPL_T_VERSION != fa_out.version)
        TEST_ERROR;

    if (SERVER_HANDSHAKE_PORT != fa_out.handshake_port)
        TEST_ERROR;

    if (strncmp(SERVER_IP_ADDRESS, (const char *)fa_out.remote_ip, H5FD_MIRROR_MAX_IP_LEN))
        TEST_ERROR;

    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    H5E_BEGIN_TRY
    {
        H5Pclose(fapl_id);
    }
    H5E_END_TRY
    return -1;
} /* end test_fapl_configuration() */

#define PRINT_BUFFER_DIFF(act, exp, len)                                                                     \
    do {                                                                                                     \
        size_t _x = 0;                                                                                       \
        while ((act)[_x] == (exp)[_x]) {                                                                     \
            _x++;                                                                                            \
        }                                                                                                    \
        if (_x != (len)) {                                                                                   \
            size_t _y = 0;                                                                                   \
            printf("First bytes differ at %zu\n", _x);                                                       \
            printf("exp  ");                                                                                 \
            for (_y = _x; _y < (len); _y++) {                                                                \
                printf("%02X", (unsigned char)(exp)[_y]);                                                    \
            }                                                                                                \
            printf("\nact  ");                                                                               \
            for (_y = _x; _y < (len); _y++) {                                                                \
                printf("%02X", (unsigned char)(act)[_y]);                                                    \
            }                                                                                                \
            printf("\n");                                                                                    \
        }                                                                                                    \
    } while (0); /* end PRINT_BUFFER_DIFF */

/*******************************************/
/* Encode/decode tests for various C types */
/*******************************************/

/* Test uint8_t encode/decode */
static int
test_encdec_uint8_t(void)
{
    unsigned char buf[8];
    unsigned char expected[8];
    const uint8_t v   = 200;
    unsigned char out = 0;

    TESTING("Mirror encode/decode of uint8_t data");

    /* Start of buffer uint8_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[0] = 200;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint8(buf, v) != 1)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint8(&out, buf) != 1)
        TEST_ERROR;
    if (v != out)
        TEST_ERROR;

    /* Middle of buffer uint8_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[3] = v;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint8((buf + 3), v) != 1)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint8(&out, (buf + 3)) != 1)
        TEST_ERROR;
    if (v != out)
        TEST_ERROR;

    /* End of buffer uint8_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[7] = v;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint8((buf + 7), v) != 1)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint8(&out, (buf + 7)) != 1)
        TEST_ERROR;
    if (v != out)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test uint16_t encode/decode */
static int
test_encdec_uint16_t(void)
{
    unsigned char  buf[8];
    unsigned char  expected[8];
    const uint16_t v   = 0x8F02;
    uint16_t       out = 0;

    TESTING("Mirror encode/decode of uint16_t data");

    /* Start of buffer uint16_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[0] = 0x8F;
    expected[1] = 0x02;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint16(buf, v) != 2)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint16(&out, buf) != 2)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    /* Middle of buffer uint16_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[3] = 0x8F;
    expected[4] = 0x02;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint16((buf + 3), v) != 2)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint16(&out, (buf + 3)) != 2)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    /* slice */
    if (H5FD__mirror_xmit_decode_uint16(&out, (buf + 4)) != 2)
        TEST_ERROR;
    if (out != 0x0200)
        TEST_ERROR;

    /* End of buffer uint16_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[6] = 0x8F;
    expected[7] = 0x02;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint16((buf + 6), v) != 2)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint16(&out, (buf + 6)) != 2)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test uint32_t encode/decode */
static int
test_encdec_uint32_t(void)
{
    unsigned char  buf[8];
    unsigned char  expected[8];
    const uint32_t v   = 0x8F020048;
    uint32_t       out = 0;

    TESTING("Mirror encode/decode of uint32_t data");

    /* Start of buffer uint32_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[0] = 0x8F;
    expected[1] = 0x02;
    expected[2] = 0x00;
    expected[3] = 0x48;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint32(buf, v) != 4)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint32(&out, buf) != 4)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    /* Middle of buffer uint32_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[3] = 0x8F;
    expected[4] = 0x02;
    expected[5] = 0x00;
    expected[6] = 0x48;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint32((buf + 3), v) != 4)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint32(&out, (buf + 3)) != 4)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;
    /* slice */
    if (H5FD__mirror_xmit_decode_uint32(&out, (buf + 4)) != 4)
        TEST_ERROR;
    if (out != 0x02004800)
        TEST_ERROR;

    /* End of buffer uint32_t */
    memset(buf, 0, 8);
    memset(expected, 0, 8);
    expected[4] = 0x8F;
    expected[5] = 0x02;
    expected[6] = 0x00;
    expected[7] = 0x48;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint32((buf + 4), v) != 4)
        TEST_ERROR;
    if (memcmp(buf, expected, 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 8);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint32(&out, (buf + 4)) != 4)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test uint64_t encode/decode */
static int
test_encdec_uint64_t(void)
{
    unsigned char  buf[16];
    unsigned char  expected[16];
    const uint64_t v   = 0x90DCBE17939CE4BB;
    uint64_t       out = 0;

    TESTING("Mirror encode/decode of uint64_t data");

    /* Start of buffer uint64_t */
    memset(buf, 0, 16);
    memset(expected, 0, 16);
    expected[0] = 0x90;
    expected[1] = 0xDC;
    expected[2] = 0xBE;
    expected[3] = 0x17;
    expected[4] = 0x93;
    expected[5] = 0x9C;
    expected[6] = 0xE4;
    expected[7] = 0xBB;
    out         = 0;
    if (H5FD__mirror_xmit_encode_uint64(buf, v) != 8)
        TEST_ERROR;
    if (memcmp(buf, expected, 16) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 16);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint64(&out, buf) != 8)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    /* Middle of buffer uint64_t */
    memset(buf, 0, 16);
    memset(expected, 0, 16);
    expected[3]  = 0x90;
    expected[4]  = 0xDC;
    expected[5]  = 0xBE;
    expected[6]  = 0x17;
    expected[7]  = 0x93;
    expected[8]  = 0x9C;
    expected[9]  = 0xE4;
    expected[10] = 0xBB;
    out          = 0;
    if (H5FD__mirror_xmit_encode_uint64((buf + 3), v) != 8)
        TEST_ERROR;
    if (memcmp(buf, expected, 16) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 16);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint64(&out, (buf + 3)) != 8)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;
    /* Slice */
    if (H5FD__mirror_xmit_decode_uint64(&out, (buf + 6)) != 8)
        TEST_ERROR;
    if (out != 0x17939CE4BB000000)
        TEST_ERROR;

    /* End of buffer uint64_t */
    memset(buf, 0, 16);
    memset(expected, 0, 16);
    expected[8]  = 0x90;
    expected[9]  = 0xDC;
    expected[10] = 0xBE;
    expected[11] = 0x17;
    expected[12] = 0x93;
    expected[13] = 0x9C;
    expected[14] = 0xE4;
    expected[15] = 0xBB;
    out          = 0;
    if (H5FD__mirror_xmit_encode_uint64((buf + 8), v) != 8)
        TEST_ERROR;
    if (memcmp(buf, expected, 16) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, 16);
        TEST_ERROR;
    }
    if (H5FD__mirror_xmit_decode_uint64(&out, (buf + 8)) != 8)
        TEST_ERROR;
    if (out != v)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/*****************************/
/* Other Encode/decode tests */
/*****************************/

/* Test xmit header structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 */
static int
test_encdec_header(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char      buf[H5FD_MIRROR_XMIT_HEADER_SIZE + 8];
    unsigned char      expected[H5FD_MIRROR_XMIT_HEADER_SIZE + 8];
    H5FD_mirror_xmit_t xmit_out;
    size_t             i = 0;

    TESTING("Mirror encode/decode of xmit header");

    /* Sanity check */
    if (14 != H5FD_MIRROR_XMIT_HEADER_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_HEADER_SIZE + 8);
    for (i = 0; i < H5FD_MIRROR_XMIT_HEADER_SIZE; i++) {
        expected[i + 2] = (unsigned char)i;
    }

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_HEADER_SIZE + 8);
    if (H5FD_mirror_xmit_encode_header((buf + 2), &xmit_mock) != H5FD_MIRROR_XMIT_HEADER_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_HEADER_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_HEADER_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_header(&xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_HEADER_SIZE)
        TEST_ERROR;
    if (xmit_out.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out.op != xmit_mock.op)
        TEST_ERROR;

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_header(&xmit_out, buf) != H5FD_MIRROR_XMIT_HEADER_SIZE)
        TEST_ERROR;
    if (xmit_out.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out.version != 0x02)
        TEST_ERROR;
    if (xmit_out.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out.op != 0x0B)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test xmit set-eoa structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 */
static int
test_encdec_set_eoa(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char          buf[H5FD_MIRROR_XMIT_EOA_SIZE + 8];
    unsigned char          expected[H5FD_MIRROR_XMIT_EOA_SIZE + 8];
    H5FD_mirror_xmit_eoa_t xmit_in;
    H5FD_mirror_xmit_eoa_t xmit_out;
    size_t                 i = 0;

    TESTING("Mirror encode/decode of xmit set-eoa");

    /* Sanity check */
    if ((14 + 9) != H5FD_MIRROR_XMIT_EOA_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");
    if (xmit_mock.op != 0x0D)
        FAIL_PUTS_ERROR("shared header structure is not in expected state");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_EOA_SIZE + 8);
    for (i = 0; i < H5FD_MIRROR_XMIT_EOA_SIZE; i++)
        expected[i + 2] = (unsigned char)i;

    /* Set xmit_in */
    xmit_in.pub      = xmit_mock; /* shared/common */
    xmit_in.type     = 0x0E;
    xmit_in.eoa_addr = 0x0F10111213141516;

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_EOA_SIZE + 8);
    if (H5FD_mirror_xmit_encode_set_eoa((buf + 2), &xmit_in) != H5FD_MIRROR_XMIT_EOA_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_EOA_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_EOA_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_set_eoa(&xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_EOA_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out.pub.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out.pub.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out.pub.op != xmit_mock.op)
        TEST_ERROR;
    if (xmit_out.type != 0x0E)
        TEST_ERROR;
    if (xmit_out.eoa_addr != 0x0F10111213141516)
        TEST_ERROR;

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_set_eoa(&xmit_out, buf) != H5FD_MIRROR_XMIT_EOA_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out.pub.version != 0x02)
        TEST_ERROR;
    if (xmit_out.pub.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out.pub.op != 0x0B)
        TEST_ERROR;
    if (xmit_out.type != 0x0C)
        TEST_ERROR;
    if (xmit_out.eoa_addr != 0x0D0E0F1011121314)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test xmit lock structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 */
static int
test_encdec_lock(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char           buf[H5FD_MIRROR_XMIT_LOCK_SIZE + 8];
    unsigned char           expected[H5FD_MIRROR_XMIT_LOCK_SIZE + 8];
    H5FD_mirror_xmit_lock_t xmit_in;
    H5FD_mirror_xmit_lock_t xmit_out;
    size_t                  i = 0;

    TESTING("Mirror encode/decode of xmit lock");

    /* Sanity check */
    if ((14 + 8) != H5FD_MIRROR_XMIT_LOCK_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");
    if (xmit_mock.op != 0x0D)
        FAIL_PUTS_ERROR("shared header structure is not in expected state");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_LOCK_SIZE + 8);
    for (i = 0; i < H5FD_MIRROR_XMIT_LOCK_SIZE; i++)
        expected[i + 2] = (unsigned char)i;

    /* Set xmit_in */
    xmit_in.pub = xmit_mock; /* shared/common */
    xmit_in.rw  = 0x0E0F101112131415;

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_LOCK_SIZE + 8);
    if (H5FD_mirror_xmit_encode_lock((buf + 2), &xmit_in) != H5FD_MIRROR_XMIT_LOCK_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_LOCK_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_LOCK_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_lock(&xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_LOCK_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out.pub.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out.pub.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out.pub.op != xmit_mock.op)
        TEST_ERROR;
    if (xmit_out.rw != 0x0E0F101112131415)
        TEST_ERROR;

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_lock(&xmit_out, buf) != H5FD_MIRROR_XMIT_LOCK_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out.pub.version != 0x02)
        TEST_ERROR;
    if (xmit_out.pub.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out.pub.op != 0x0B)
        TEST_ERROR;
    if (xmit_out.rw != 0x0C0D0E0F10111213)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* Test xmit open structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 *
 * Verifies that the first zero character in the filepath will end the
 * string, with all following bytes in the encoded buffer being zeroed.
 */
static int
test_encdec_open(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char           *buf      = NULL;
    unsigned char           *expected = NULL;
    H5FD_mirror_xmit_open_t *xmit_in  = NULL;
    H5FD_mirror_xmit_open_t *xmit_out = NULL;

    TESTING("Mirror encode/decode of xmit open");

    /* Sanity check */
    if ((14 + 20 + 4097) != H5FD_MIRROR_XMIT_OPEN_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");
    if (xmit_mock.op != 0x0D)
        FAIL_PUTS_ERROR("shared header structure is not in expected state");

    /* Allocate memory */
    if (NULL == (buf = malloc((H5FD_MIRROR_XMIT_OPEN_SIZE + 8) * sizeof(unsigned char))))
        FAIL_PUTS_ERROR("Unable to allocate memory for buf");
    if (NULL == (expected = malloc((H5FD_MIRROR_XMIT_OPEN_SIZE + 8) * sizeof(unsigned char))))
        FAIL_PUTS_ERROR("Unable to allocate memory for expected");
    if (NULL == (xmit_in = malloc(sizeof(H5FD_mirror_xmit_open_t))))
        FAIL_PUTS_ERROR("Unable to allocate memory for xmit_in");
    if (NULL == (xmit_out = malloc(sizeof(H5FD_mirror_xmit_open_t))))
        FAIL_PUTS_ERROR("Unable to allocate memory for xmit_out");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_OPEN_SIZE + 8);
    for (size_t i = 0; i < H5FD_MIRROR_XMIT_OPEN_SIZE; i++) {
        /* 0x100 is "zero" in a byte, so encode will treat it as a NULL-
         * terminator in the filepath string. Expect all zeroes following.
         */
        expected[i + 2] = (i > 0xFF) ? 0 : (unsigned char)i;
    }

    /* Set xmit_in */
    xmit_in->pub         = xmit_mock; /* shared/common */
    xmit_in->flags       = 0x0E0F1011;
    xmit_in->maxaddr     = 0x1213141516171819;
    xmit_in->size_t_blob = 0x1A1B1C1D1E1F2021;
    for (size_t i = 0x22; i < H5FD_MIRROR_XMIT_FILEPATH_MAX + 0x22; i++) {
        /* Non-zero values repeat after 0x100, but will not be encoded */
        xmit_in->filename[i - 0x22] = (char)(i % 0x100);
    }
    xmit_in->filename[H5FD_MIRROR_XMIT_FILEPATH_MAX - 1] = 0;

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_OPEN_SIZE + 8);
    if (H5FD_mirror_xmit_encode_open((buf + 2), xmit_in) != H5FD_MIRROR_XMIT_OPEN_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_OPEN_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_OPEN_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_open(xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_OPEN_SIZE)
        TEST_ERROR;
    if (xmit_out->pub.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out->pub.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out->pub.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out->pub.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out->pub.op != xmit_mock.op)
        TEST_ERROR;
    if (xmit_out->flags != xmit_in->flags)
        TEST_ERROR;
    if (xmit_out->maxaddr != xmit_in->maxaddr)
        TEST_ERROR;
    if (xmit_out->size_t_blob != xmit_in->size_t_blob)
        TEST_ERROR;
    if (strncmp(xmit_out->filename, xmit_in->filename, H5FD_MIRROR_XMIT_FILEPATH_MAX) != 0) {
        PRINT_BUFFER_DIFF(xmit_out->filename, xmit_in->filename, H5FD_MIRROR_XMIT_FILEPATH_MAX);
        TEST_ERROR;
    }

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_open(xmit_out, buf) != H5FD_MIRROR_XMIT_OPEN_SIZE)
        TEST_ERROR;
    if (xmit_out->pub.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out->pub.version != 0x02)
        TEST_ERROR;
    if (xmit_out->pub.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out->pub.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out->pub.op != 0x0B)
        TEST_ERROR;
    if (xmit_out->flags != 0x0C0D0E0F)
        TEST_ERROR;
    if (xmit_out->maxaddr != 0x1011121314151617)
        TEST_ERROR;
    if (xmit_out->size_t_blob != 0x18191A1B1C1D1E1F)
        TEST_ERROR;
    /* Update expected "filepath" in structure */
    for (size_t i = 0x20; i < H5FD_MIRROR_XMIT_FILEPATH_MAX + 0x20; i++)
        xmit_in->filename[i - 0x20] = (i > 0xFF) ? 0 : (char)i;
    if (strncmp(xmit_out->filename, xmit_in->filename, H5FD_MIRROR_XMIT_FILEPATH_MAX) != 0) {
        PRINT_BUFFER_DIFF(xmit_out->filename, xmit_in->filename, H5FD_MIRROR_XMIT_FILEPATH_MAX);
        TEST_ERROR;
    }

    free(buf);
    free(expected);
    free(xmit_in);
    free(xmit_out);

    PASSED();
    return 0;

error:
    free(buf);
    free(expected);
    free(xmit_in);
    free(xmit_out);

    return -1;
}

/* Test xmit reply structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 *
 * Verifies that the first zero character in the filepath will end the
 * string, with all following bytes in the encoded buffer being zeroed.
 */
static int
test_encdec_reply(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char            buf[H5FD_MIRROR_XMIT_REPLY_SIZE + 8];
    unsigned char            expected[H5FD_MIRROR_XMIT_REPLY_SIZE + 8];
    H5FD_mirror_xmit_reply_t xmit_in;
    H5FD_mirror_xmit_reply_t xmit_out;
    size_t                   i = 0;

    TESTING("Mirror encode/decode of xmit reply");

    /* Sanity check */
    if ((14 + 4 + 256) != H5FD_MIRROR_XMIT_REPLY_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");
    if (xmit_mock.op != 0x0D)
        FAIL_PUTS_ERROR("shared header structure is not in expected state");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_REPLY_SIZE + 8);
    for (i = 0; i < H5FD_MIRROR_XMIT_REPLY_SIZE; i++) {
        /* 0x100 is "zero" in a byte, so encode will treat it as a NULL-
         * terminator in the filepath string. Expect all zeroes following.
         */
        expected[i + 2] = (i > 0xFF) ? 0 : (unsigned char)i;
    }

    /* Set xmit_in */
    xmit_in.pub    = xmit_mock; /* shared/common */
    xmit_in.status = 0x0E0F1011;
    for (i = 0x12; i < H5FD_MIRROR_STATUS_MESSAGE_MAX + 0x12; i++) {
        /* Non-zero values repeat after 0x100, but will not be encoded */
        xmit_in.message[i - 0x12] = (char)(i % 0x100);
    }
    xmit_in.message[H5FD_MIRROR_STATUS_MESSAGE_MAX - 1] = 0;

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_REPLY_SIZE + 8);
    if (H5FD_mirror_xmit_encode_reply((buf + 2), &xmit_in) != H5FD_MIRROR_XMIT_REPLY_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_REPLY_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_REPLY_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_reply(&xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_REPLY_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out.pub.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out.pub.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out.pub.op != xmit_mock.op)
        TEST_ERROR;
    if (xmit_out.status != xmit_in.status)
        TEST_ERROR;
    if (strncmp(xmit_out.message, xmit_in.message, H5FD_MIRROR_STATUS_MESSAGE_MAX) != 0) {
        PRINT_BUFFER_DIFF(xmit_out.message, xmit_in.message, H5FD_MIRROR_STATUS_MESSAGE_MAX);
        TEST_ERROR;
    }

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_reply(&xmit_out, buf) != H5FD_MIRROR_XMIT_REPLY_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out.pub.version != 0x02)
        TEST_ERROR;
    if (xmit_out.pub.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out.pub.op != 0x0B)
        TEST_ERROR;
    if (xmit_out.status != 0x0C0D0E0F)
        TEST_ERROR;
    /* Update expected "message" in structure */
    for (i = 0x10; i < H5FD_MIRROR_STATUS_MESSAGE_MAX + 0x10; i++)
        xmit_in.message[i - 0x10] = (i > 0xFF) ? 0 : (char)i;
    if (strncmp(xmit_out.message, xmit_in.message, H5FD_MIRROR_STATUS_MESSAGE_MAX) != 0) {
        PRINT_BUFFER_DIFF(xmit_out.message, xmit_in.message, H5FD_MIRROR_STATUS_MESSAGE_MAX);
        TEST_ERROR;
    }

    PASSED();
    return 0;

error:
    return -1;
}

/* Test xmit write structure encode/decode
 * Write bogus but easily verifiable data to inside a buffer, and compare.
 * Then decode the buffer and compare the structure contents.
 * Then repeat from a different offset in the buffer and compare.
 */
static int
test_encdec_write(H5FD_mirror_xmit_t xmit_mock)
{
    unsigned char            buf[H5FD_MIRROR_XMIT_WRITE_SIZE + 8];
    unsigned char            expected[H5FD_MIRROR_XMIT_WRITE_SIZE + 8];
    H5FD_mirror_xmit_write_t xmit_in;
    H5FD_mirror_xmit_write_t xmit_out;
    size_t                   i = 0;

    TESTING("Mirror encode/decode of xmit write");

    /* Sanity check */
    if ((14 + 17) != H5FD_MIRROR_XMIT_WRITE_SIZE)
        FAIL_PUTS_ERROR("Header size definition does not match test\n");
    if (xmit_mock.op != 0x0D)
        FAIL_PUTS_ERROR("shared header structure is not in expected state");

    /* Populate the expected buffer; expect end padding of 0xFF */
    memset(expected, 0xFF, H5FD_MIRROR_XMIT_WRITE_SIZE + 8);
    for (i = 0; i < H5FD_MIRROR_XMIT_WRITE_SIZE; i++)
        expected[i + 2] = (unsigned char)i;

    /* Set xmit_in */
    xmit_in.pub    = xmit_mock; /* shared/common */
    xmit_in.type   = 0x0E;
    xmit_in.offset = 0x0F10111213141516;
    xmit_in.size   = 0x1718191A1B1C1D1E;

    /* Encode, and compare buffer contents
     * Initial buffer is filled with 0xFF to match expected padding
     */
    memset(buf, 0xFF, H5FD_MIRROR_XMIT_WRITE_SIZE + 8);
    if (H5FD_mirror_xmit_encode_write((buf + 2), &xmit_in) != H5FD_MIRROR_XMIT_WRITE_SIZE)
        TEST_ERROR;
    if (memcmp(buf, expected, H5FD_MIRROR_XMIT_WRITE_SIZE + 8) != 0) {
        PRINT_BUFFER_DIFF(buf, expected, H5FD_MIRROR_XMIT_WRITE_SIZE + 8);
        TEST_ERROR;
    }

    /* Decode from buffer */
    if (H5FD_mirror_xmit_decode_write(&xmit_out, (buf + 2)) != H5FD_MIRROR_XMIT_WRITE_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != xmit_mock.magic)
        TEST_ERROR;
    if (xmit_out.pub.version != xmit_mock.version)
        TEST_ERROR;
    if (xmit_out.pub.session_token != xmit_mock.session_token)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != xmit_mock.xmit_count)
        TEST_ERROR;
    if (xmit_out.pub.op != xmit_mock.op)
        TEST_ERROR;
    if (xmit_out.type != 0x0E)
        TEST_ERROR;
    if (xmit_out.offset != 0x0F10111213141516)
        TEST_ERROR;
    if (xmit_out.size != 0x1718191A1B1C1D1E)
        TEST_ERROR;

    /* Decode from different offset in buffer
     * Observe changes when ingesting the padding
     */
    if (H5FD_mirror_xmit_decode_write(&xmit_out, buf) != H5FD_MIRROR_XMIT_WRITE_SIZE)
        TEST_ERROR;
    if (xmit_out.pub.magic != 0xFFFF0001)
        TEST_ERROR;
    if (xmit_out.pub.version != 0x02)
        TEST_ERROR;
    if (xmit_out.pub.session_token != 0x03040506)
        TEST_ERROR;
    if (xmit_out.pub.xmit_count != 0x0708090A)
        TEST_ERROR;
    if (xmit_out.pub.op != 0x0B)
        TEST_ERROR;
    if (xmit_out.type != 0x0C)
        TEST_ERROR;
    if (xmit_out.offset != 0x0D0E0F1011121314)
        TEST_ERROR;
    if (xmit_out.size != 0x15161718191A1B1C)
        TEST_ERROR;

    PASSED();
    return 0;

error:
    return -1;
}

/* ---------------------------------------------------------------------------
 * Function:    create_mirroring_split_fapl
 *
 * Purpose:     Create and populate a mirroring FAPL ID.
 *              Creates target files with the given base name -- ideally the
 *              test name -- and creates mirroring/split FAPL set to use the
 *              global mirroring info and a sec2 R/W channel driver.
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: HID of the top-level (splitter) FAPL, a non-negative
 *                       value.
 *              Failure: H5I_INVALID_HID, a negative value.
 * ---------------------------------------------------------------------------
 */
static hid_t
create_mirroring_split_fapl(const char *basename, struct mirrortest_filenames *names,
                            const struct mt_opts *opts)
{
    H5FD_splitter_vfd_config_t *splitter_config = NULL;
    H5FD_mirror_fapl_t          mirror_conf;
    hid_t                       ret_value = H5I_INVALID_HID;

    if (NULL == (splitter_config = malloc(sizeof(H5FD_splitter_vfd_config_t))))
        TEST_ERROR;

    /* Initialize the fapls, too, so the library doesn't try to
     * close non-existing IDs on errors
     */
    splitter_config->magic          = H5FD_SPLITTER_MAGIC;
    splitter_config->version        = H5FD_CURR_SPLITTER_VFD_CONFIG_VERSION;
    splitter_config->ignore_wo_errs = false;
    splitter_config->rw_fapl_id     = H5I_INVALID_HID;
    splitter_config->wo_fapl_id     = H5I_INVALID_HID;

    if (basename == NULL || *basename == '\0')
        TEST_ERROR;

    /* Create Splitter R/W channel driver (sec2) */
    if ((splitter_config->rw_fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
        TEST_ERROR;
    if (H5Pset_fapl_sec2(splitter_config->rw_fapl_id) < 0)
        TEST_ERROR;

    /* Create Splitter W/O channel driver (mirror) */
    mirror_conf.magic          = H5FD_MIRROR_FAPL_MAGIC;
    mirror_conf.version        = H5FD_MIRROR_CURR_FAPL_T_VERSION;
    mirror_conf.handshake_port = opts->portno;
    if (strncpy(mirror_conf.remote_ip, opts->ip, H5FD_MIRROR_MAX_IP_LEN) == NULL)
        TEST_ERROR;
    if ((splitter_config->wo_fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
        TEST_ERROR;
    if (H5Pset_fapl_mirror(splitter_config->wo_fapl_id, &mirror_conf) < 0)
        TEST_ERROR;

    /* Build r/w, w/o, and log file paths */
    if (build_paths(basename, splitter_config, names) < 0)
        TEST_ERROR;

    /* Set file paths for w/o and logfile */
    if (strncpy(splitter_config->wo_path, (const char *)names->wo, H5FD_SPLITTER_PATH_MAX) == NULL)
        TEST_ERROR;
    if (strncpy(splitter_config->log_file_path, (const char *)names->log, H5FD_SPLITTER_PATH_MAX) == NULL)
        TEST_ERROR;

    /* Create Splitter FAPL */
    if ((ret_value = H5Pcreate(H5P_FILE_ACCESS)) < 0)
        TEST_ERROR;
    if (H5Pset_fapl_splitter(ret_value, splitter_config) < 0)
        TEST_ERROR;

    /* Close FAPLs created for child channels */
    if (H5Pclose(splitter_config->rw_fapl_id) < 0)
        TEST_ERROR;
    if (H5Pclose(splitter_config->wo_fapl_id) < 0)
        TEST_ERROR;

    free(splitter_config);

    return ret_value;

error:
    H5E_BEGIN_TRY
    {
        H5Pclose(splitter_config->wo_fapl_id);
        H5Pclose(splitter_config->rw_fapl_id);
        H5Pclose(ret_value);
    }
    H5E_END_TRY
    free(splitter_config);

    return H5I_INVALID_HID;
} /* end create_mirroring_split_fapl() */

/* ---------------------------------------------------------------------------
 * Function:    test_create_and_close
 *
 * Purpose:     Test/demonstrate a do-nothing file open and close.
 *
 *              Verifying file existence and contents is part of other tests.
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_create_and_close(const struct mt_opts *opts)
{
    struct mirrortest_filenames *names   = NULL;
    hid_t                        file_id = H5I_INVALID_HID;
    hid_t                        fapl_id = H5I_INVALID_HID;

    TESTING("File creation and immediate close");

    if (NULL == (names = malloc(sizeof(struct mirrortest_filenames))))
        TEST_ERROR;

    /* Create FAPL for splitter[sec2|mirror] */
    if ((fapl_id = create_mirroring_split_fapl("basic_create", names, opts)) < 0)
        TEST_ERROR;

    if ((file_id = H5Fcreate(names->rw, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
        TEST_ERROR;

    if (H5Fclose(file_id) < 0)
        TEST_ERROR;
    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;

    free(names);

    PASSED();
    return 0;

error:
    free(names);
    H5E_BEGIN_TRY
    {
        H5Fclose(file_id);
        H5Pclose(fapl_id);
    }
    H5E_END_TRY
    return -1;
} /* end test_create_and_close() */

/* ----------------------------------------------------------------------------
 * Function:    create_datasets
 *
 * Purpose:     Given a file ID and least and greateset dataset indices, create
 *              populated chunked datasets in the target file from min_dset to
 *              (and including) max_dset.
 *              Uses #defined constants to determine chunk and dataset sizes
 *              and values.
 *
 * Return:      SUCCEED/FAIL
 * ----------------------------------------------------------------------------
 */
static herr_t
create_datasets(hid_t file_id, unsigned min_dset, unsigned max_dset)
{
    hid_t        dataspace_ids[MAX_DSET_COUNT + 1];
    hid_t        dataset_ids[MAX_DSET_COUNT + 1];
    hid_t        filespace_ids[MAX_DSET_COUNT + 1];
    int          data_chunk[CHUNK_DIM][CHUNK_DIM];
    unsigned int i, j, k, l, m;
    hsize_t      offset[2];
    hid_t        memspace_id   = H5I_INVALID_HID;
    hsize_t      a_size[2]     = {CHUNK_DIM, CHUNK_DIM};
    hsize_t      chunk_dims[2] = {CHUNK_DIM, CHUNK_DIM};
    hsize_t      dset_dims[2]  = {DSET_DIM, DSET_DIM};

    assert(file_id >= 0);
    assert(min_dset <= max_dset);
    assert(max_dset <= MAX_DSET_COUNT);

    LOGPRINT(2, "create_dataset()\n");

    /* Initialize ID arrays */
    for (i = 0; i < MAX_DSET_COUNT; i++) {
        LOGPRINT(3, "clearing IDs [%d]\n", i);
        dataspace_ids[i] = H5I_INVALID_HID;
        dataset_ids[i]   = H5I_INVALID_HID;
        filespace_ids[i] = H5I_INVALID_HID;
    }

    /* Generate dataspace, dataset, and 'filespace' IDs */
    if (_create_chunking_ids(file_id, min_dset, max_dset, chunk_dims, dset_dims, dataspace_ids, filespace_ids,
                             dataset_ids, &memspace_id) < 0)
        TEST_ERROR;

    /* Initialize (write) all datasets in a "round robin"...
     * for a given chunk 'location', write chunk data to each dataset.
     */
    for (i = 0; i < DSET_DIM; i += CHUNK_DIM) {
        LOGPRINT(3, "i: %d\n", i);
        for (j = 0; j < DSET_DIM; j += CHUNK_DIM) {
            LOGPRINT(3, "  j: %d\n", j);
            for (m = min_dset; m <= max_dset; m++) {
                LOGPRINT(3, "    m: %d\n", m);
                for (k = 0; k < CHUNK_DIM; k++) {
                    for (l = 0; l < CHUNK_DIM; l++) {
                        data_chunk[k][l] = (int)((DSET_DIM * DSET_DIM * m) + (DSET_DIM * (i + k)) + j + l);
                        LOGPRINT(3, "      data_chunk[%d][%d]: %d\n", k, l, data_chunk[k][l]);
                    }
                }

                /* Select on disk hyperslab */
                offset[0] = (hsize_t)i;
                offset[1] = (hsize_t)j;
                LOGPRINT(3, "    H5Sselect_hyperslab()\n");
                if (H5Sselect_hyperslab(filespace_ids[m], H5S_SELECT_SET, offset, NULL, a_size, NULL) < 0)
                    TEST_ERROR;

                LOGPRINT(3, "    H5Dwrite()\n");
                if (H5Dwrite(dataset_ids[m], H5T_NATIVE_INT, memspace_id, filespace_ids[m], H5P_DEFAULT,
                             data_chunk) < 0)
                    TEST_ERROR;
            }
        }
    }

    /* Read and verify data from datasets */
    if (_verify_datasets(min_dset, max_dset, filespace_ids, dataset_ids, memspace_id) < 0)
        TEST_ERROR;

    /* Cleanup */
    if (_close_chunking_ids(min_dset, max_dset, dataspace_ids, filespace_ids, dataset_ids, &memspace_id) < 0)
        TEST_ERROR;

    return SUCCEED;

error:
    (void)_close_chunking_ids(min_dset, max_dset, dataspace_ids, filespace_ids, dataset_ids, &memspace_id);
    LOGPRINT(1, "create_datasets() FAILED\n");
    return FAIL;
} /* end create_datasets() */

/* ----------------------------------------------------------------------------
 * Function:   _create_chunking_ids
 *
 * Purpose:    Create new IDs to be used with the associated file.
 *
 * Return:     SUCCEED/FAIL
 * ----------------------------------------------------------------------------
 */
static herr_t
_create_chunking_ids(hid_t file_id, unsigned min_dset, unsigned max_dset, hsize_t *chunk_dims,
                     hsize_t *dset_dims, hid_t *dataspace_ids, hid_t *filespace_ids, hid_t *dataset_ids,
                     hid_t *memspace_id)
{
    char  dset_name[DSET_NAME_LEN + 1];
    hid_t dcpl_id = H5I_INVALID_HID;

    LOGPRINT(2, "_create_chunking_ids()\n");

    /* Create chunking DCPL */
    if ((dcpl_id = H5Pcreate(H5P_DATASET_CREATE)) < 0)
        TEST_ERROR;
    if (H5Pset_chunk(dcpl_id, 2, chunk_dims) < 0)
        TEST_ERROR;

    /* Create dataspace IDs */
    for (unsigned m = min_dset; m <= max_dset; m++) {
        if ((dataspace_ids[m] = H5Screate_simple(2, dset_dims, NULL)) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to create dataspace ID %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    /* Create dataset IDs */
    for (unsigned m = min_dset; m <= max_dset; m++) {
        if (snprintf(dset_name, DSET_NAME_LEN, "/dset%03d", m) > DSET_NAME_LEN) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to compose dset name %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }

        if ((dataset_ids[m] = H5Dcreate2(file_id, dset_name, H5T_STD_I32BE, dataspace_ids[m], H5P_DEFAULT,
                                         dcpl_id, H5P_DEFAULT)) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to create dset ID %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    /* Get file space IDs */
    for (unsigned m = min_dset; m <= max_dset; m++) {
        if ((filespace_ids[m] = H5Dget_space(dataset_ids[m])) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to create filespace ID %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    /* Create mem space to be used to read and write chunks */
    if ((*memspace_id = H5Screate_simple(2, chunk_dims, NULL)) < 0)
        TEST_ERROR;

    /* Clean up the DCPL  */
    if (H5Pclose(dcpl_id) < 0)
        TEST_ERROR;

    return SUCCEED;

error:
    H5E_BEGIN_TRY
    {
        /* Note that it's the caller's responsibility to clean up any IDs
         * passed back via out parameters
         */
        H5Pclose(dcpl_id);
    }
    H5E_END_TRY

    LOGPRINT(1, "_create_chunking_ids() FAILED\n");

    return FAIL;
} /* end _create_chunking_ids() */

/* ----------------------------------------------------------------------------
 * Function:    _open_chunking_ids
 *
 * Purpose:     Open/access IDs from the given file.
 *
 * Return:      SUCCEED/FAIL
 * ----------------------------------------------------------------------------
 */
static herr_t
_open_chunking_ids(hid_t file_id, unsigned min_dset, unsigned max_dset, hsize_t *chunk_dims,
                   hid_t *filespace_ids, hid_t *dataset_ids, hid_t *memspace_id)
{
    char dset_name[DSET_NAME_LEN + 1];

    LOGPRINT(2, "_open_chunking_ids()\n");

    /* Open dataset IDs */
    for (unsigned m = min_dset; m <= max_dset; m++) {
        if (snprintf(dset_name, DSET_NAME_LEN, "/dset%03d", m) > DSET_NAME_LEN) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to compose dset name %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }

        if ((dataset_ids[m] = H5Dopen2(file_id, dset_name, H5P_DEFAULT)) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to open dset ID %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    /* Open filespace IDs */
    for (unsigned m = min_dset; m <= max_dset; m++) {
        if ((filespace_ids[m] = H5Dget_space(dataset_ids[m])) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to get filespace ID %d\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    /* Create mem space to be used to read and write chunks */
    if ((*memspace_id = H5Screate_simple(2, chunk_dims, NULL)) < 0)
        TEST_ERROR;

    return SUCCEED;

error:
    /* Note that the caller is responsible for cleaning up IDs returned
     * as out parameters
     */
    LOGPRINT(1, "_open_chunking_ids() FAILED\n");
    return FAIL;
} /* end _open_chunking_ids() */

/* ---------------------------------------------------------------------------
 * Function:    _close_chunking_ids
 *
 * Purpose:     Close IDs that were created or opened.
 *              Pass NULL into `dataspace_ids` when closing items opened with
 *              _open_chunking_ids(). (as opposed to created IDs)
 *
 * Return:      SUCCEED/FAIL
 * ---------------------------------------------------------------------------
 */
static herr_t
_close_chunking_ids(unsigned min_dset, unsigned max_dset, hid_t *dataspace_ids, hid_t *filespace_ids,
                    hid_t *dataset_ids, hid_t *memspace_id)
{
    LOGPRINT(2, "_close_chunking_ids()\n");

    for (unsigned m = min_dset; m <= max_dset; m++) {
        LOGPRINT(3, "closing ids[%d]\n", m);
        if (dataspace_ids) {
            if (H5Sclose(dataspace_ids[m]) < 0) {
                snprintf(mesg, MIRR_MESG_SIZE, "unable to close dataspace_id[%d]\n", m);
                FAIL_PUTS_ERROR(mesg);
            }
        }
        if (H5Dclose(dataset_ids[m]) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to close dataset_id[%d]\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
        if (H5Sclose(filespace_ids[m]) < 0) {
            snprintf(mesg, MIRR_MESG_SIZE, "unable to close filespace_id[%d]\n", m);
            FAIL_PUTS_ERROR(mesg);
        }
    }

    if (*memspace_id != H5I_INVALID_HID)
        if (H5Sclose(*memspace_id) < 0)
            TEST_ERROR;

    return SUCCEED;

error:
    LOGPRINT(1, "_close_chunking_ids() FAILED\n");
    return FAIL;
} /* end _close_chunking_ids() */

/* ---------------------------------------------------------------------------
 * Function:    _verify_datasets
 *
 * Purpose:     Check that each chunk's contents are as expected, as pertaining
 *              to create_datasets().
 *
 * Return:      SUCCEED/FAIL
 * ---------------------------------------------------------------------------
 */
static herr_t
_verify_datasets(unsigned min_dset, unsigned max_dset, hid_t *filespace_ids, hid_t *dataset_ids,
                 hid_t memspace_id)
{
    unsigned i, j, k, l, m;
    int      data_chunk[CHUNK_DIM][CHUNK_DIM];
    hsize_t  offset[2];
    hsize_t  a_size[2] = {CHUNK_DIM, CHUNK_DIM};

    LOGPRINT(2, "_verify_datasets()\n");

    for (i = 0; i < DSET_DIM; i += CHUNK_DIM) {
        LOGPRINT(3, "i: %d\n", i);
        for (j = 0; j < DSET_DIM; j += CHUNK_DIM) {
            LOGPRINT(3, "  j: %d\n", j);
            for (m = min_dset; m <= max_dset; m++) {
                LOGPRINT(3, "    m: %d\n", m);

                /* select on disk hyperslab */
                offset[0] = (hsize_t)i;
                offset[1] = (hsize_t)j;
                if (H5Sselect_hyperslab(filespace_ids[m], H5S_SELECT_SET, offset, NULL, a_size, NULL) < 0)
                    TEST_ERROR;

                if (H5Dread(dataset_ids[m], H5T_NATIVE_INT, memspace_id, filespace_ids[m], H5P_DEFAULT,
                            data_chunk) < 0) {
                    snprintf(mesg, MIRR_MESG_SIZE, "      H5Dread() [%d][%d][%d]\n", i, j, m);
                    FAIL_PUTS_ERROR(mesg);
                }

                for (k = 0; k < CHUNK_DIM; k++) {
                    for (l = 0; l < CHUNK_DIM; l++) {
                        if ((unsigned)data_chunk[k][l] !=
                            ((DSET_DIM * DSET_DIM * m) + (DSET_DIM * (i + k)) + j + l)) {
                            snprintf(mesg, MIRR_MESG_SIZE, "      MISMATCH [%d][%d][%d][%d][%d]\n", i, j, m,
                                     k, l);
                            FAIL_PUTS_ERROR(mesg);
                        }
                    }
                }
            }
        }
    }

    return SUCCEED;

error:
    LOGPRINT(1, "_verify_datasets() FAILED\n");
    return FAIL;
} /* end _verify_datasets() */

/* ---------------------------------------------------------------------------
 * Function:    verify_datasets
 *
 * Purpose:     Inspect the datasets in the file created by create_datasets().
 *              Wrapper for _verify_datasets() -- this function sets up and
 *              tears down accessor information.
 *
 * Return:      SUCCEED/FAIL
 * ---------------------------------------------------------------------------
 */
static herr_t
verify_datasets(hid_t file_id, unsigned min_dset, unsigned max_dset)
{
    hid_t   dataset_ids[MAX_DSET_COUNT + 1];
    hid_t   filespace_ids[MAX_DSET_COUNT + 1];
    hid_t   memspace_id   = H5I_INVALID_HID;
    hsize_t chunk_dims[2] = {CHUNK_DIM, CHUNK_DIM};

    assert(file_id >= 0);
    assert(min_dset <= max_dset);
    assert(max_dset <= MAX_DSET_COUNT);

    LOGPRINT(2, "verify_datasets()\n");

    /* Initialize ID arrays */
    for (unsigned i = 0; i < MAX_DSET_COUNT; i++) {
        LOGPRINT(3, "clearing IDs [%d]\n", i);
        dataset_ids[i]   = H5I_INVALID_HID;
        filespace_ids[i] = H5I_INVALID_HID;
    }

    /* Generate dataspace, dataset, and 'filespace' IDs */
    if (_open_chunking_ids(file_id, min_dset, max_dset, chunk_dims, filespace_ids, dataset_ids,
                           &memspace_id) < 0)
        TEST_ERROR;

    /* Read and verify data from datasets */
    if (_verify_datasets(min_dset, max_dset, filespace_ids, dataset_ids, memspace_id) < 0)
        TEST_ERROR;

    /* Cleanup */
    if (_close_chunking_ids(min_dset, max_dset, NULL, filespace_ids, dataset_ids, &memspace_id) < 0)
        TEST_ERROR;

    return SUCCEED;

error:
    LOGPRINT(1, "verify_datasets() FAILED\n");
    (void)_close_chunking_ids(min_dset, max_dset, NULL, filespace_ids, dataset_ids, &memspace_id);
    return FAIL;

} /* end verify_datasets() */

/* ---------------------------------------------------------------------------
 * Function:    test_basic_dataset_write
 *
 * Purpose:     Create and close files; repoen files and write a dataset,
 *              close; compare files.
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_basic_dataset_write(const struct mt_opts *opts)
{
    struct mirrortest_filenames *names     = NULL;
    hid_t                        file_id   = H5I_INVALID_HID;
    hid_t                        fapl_id   = H5I_INVALID_HID;
    hid_t                        dset_id   = H5I_INVALID_HID;
    hid_t                        dspace_id = H5I_INVALID_HID;
    hid_t                        dtype_id  = H5T_NATIVE_INT;
    hsize_t                      dims[2]   = {DATABUFFER_SIZE, DATABUFFER_SIZE};
    int                         *buf       = NULL;
    int                          i         = 0;
    int                          j         = 0;

    TESTING("Mirror open and dataset writing");

    if (NULL == (names = malloc(sizeof(struct mirrortest_filenames))))
        TEST_ERROR;

    /* Create FAPL for Splitter[sec2|mirror] */
    if ((fapl_id = create_mirroring_split_fapl("basic_write", names, opts)) < 0)
        TEST_ERROR;

    /* Prepare data to be written */
    if (NULL == (buf = malloc(DATABUFFER_SIZE * DATABUFFER_SIZE * sizeof(int))))
        TEST_ERROR;
    for (i = 0; i < DATABUFFER_SIZE; i++) {
        for (j = 0; j < DATABUFFER_SIZE; j++) {
            int k  = i * DATABUFFER_SIZE + j;
            buf[k] = k;
        }
    }

    /* -------------------- */
    /* TEST: Create and Close */

    if ((file_id = H5Fcreate(names->rw, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
        TEST_ERROR;
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Repoen and Write */

    if ((file_id = H5Fopen(names->rw, H5F_ACC_RDWR, fapl_id)) < 0)
        TEST_ERROR;

    if ((dspace_id = H5Screate_simple(2, dims, NULL)) < 0)
        TEST_ERROR;
    if ((dset_id =
             H5Dcreate2(file_id, "dataset", dtype_id, dspace_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
        TEST_ERROR;

    if (H5Dwrite(dset_id, dtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
        TEST_ERROR;

    /* Cleanup */

    if (H5Dclose(dset_id) < 0)
        TEST_ERROR;
    if (H5Sclose(dspace_id) < 0)
        TEST_ERROR;
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;
    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Verify that the R/W and W/O files are identical */

    if (h5_compare_file_bytes(names->rw, names->wo) < 0)
        TEST_ERROR;

    free(buf);
    free(names);

    PASSED();
    return 0;

error:
    free(buf);
    free(names);

    H5E_BEGIN_TRY
    {
        H5Fclose(file_id);
        H5Dclose(dset_id);
        H5Sclose(dspace_id);
        H5Pclose(fapl_id);
    }
    H5E_END_TRY
    return -1;
} /* end test_basic_dataset_write() */

/* ---------------------------------------------------------------------------
 * Function:    test_chunked_dataset_write
 *
 * Purpose:     Create and close files; repoen files and write a dataset,
 *              close; compare files.
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_chunked_dataset_write(const struct mt_opts *opts)
{
    struct mirrortest_filenames *names = NULL;

    hid_t file_id = H5I_INVALID_HID;
    hid_t fapl_id = H5P_DEFAULT;

    TESTING("Mirror open and dataset writing (chunked)");

    if (NULL == (names = malloc(sizeof(struct mirrortest_filenames))))
        TEST_ERROR;

    /* Create FAPL for Splitter[sec2|mirror] */
    if ((fapl_id = create_mirroring_split_fapl("chunked_write", names, opts)) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Create and Close */

    if ((file_id = H5Fcreate(names->rw, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
        TEST_ERROR;
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Reopen and Write */

    if ((file_id = H5Fopen(names->rw, H5F_ACC_RDWR, fapl_id)) < 0)
        TEST_ERROR;

    /* Write datasets to file */
    if (create_datasets(file_id, 0, MAX_DSET_COUNT) < 0)
        TEST_ERROR;

    /* Close to 'flush to disk', and reopen file */
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    /* Reopen file */
    if ((file_id = H5Fopen(names->rw, H5F_ACC_RDWR, fapl_id)) < 0)
        TEST_ERROR;

    /* Verify written data integrity */
    if (verify_datasets(file_id, 0, MAX_DSET_COUNT) < 0)
        TEST_ERROR;

    /* Cleanup */
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;
    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Verify that the R/W and W/O files are identical */

    if (h5_compare_file_bytes(names->rw, names->wo) < 0) {
        TEST_ERROR;
    }

    free(names);

    PASSED();
    return 0;

error:
    free(names);
    H5E_BEGIN_TRY
    {
        H5Fclose(file_id);
        H5Pclose(fapl_id);
    }
    H5E_END_TRY
    return -1;
} /* end test_chunked_dataset_write() */

/* ---------------------------------------------------------------------------
 * Function:    test_on_disk_zoo
 *
 * Purpose:     Verify that the mirror can handle the passing of all the
 *              various on-disk data structures over the wire, as implemented
 *              in genall5.c:create_zoo().
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_on_disk_zoo(const struct mt_opts *opts)
{
    const char                   grp_name[] = "/only";
    struct mirrortest_filenames *names      = NULL;
    hid_t                        file_id    = H5I_INVALID_HID;
    hid_t                        grp_id     = H5I_INVALID_HID;
    hid_t                        fapl_id    = H5I_INVALID_HID;

    TESTING("'Zoo' of on-disk structures");

    if (NULL == (names = malloc(sizeof(struct mirrortest_filenames))))
        TEST_ERROR;

    /* Create FAPL for Splitter[sec2|mirror] */
    if ((fapl_id = create_mirroring_split_fapl("zoo", names, opts)) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Create file    */
    if ((file_id = H5Fcreate(names->rw, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
        TEST_ERROR;

    if ((grp_id = H5Gcreate2(file_id, grp_name, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
        TEST_ERROR;

    /* Create datasets in file, close (flush) and reopen, validate.
     * Use of ( pass ) a conceit required for using create_ and validate_zoo()
     * from cache_common and/or genall5.
     */

    if (pass)
        create_zoo(file_id, grp_name, 0);
    if (pass) {
        if (H5Fclose(file_id) < 0)
            TEST_ERROR;
        if ((file_id = H5Fopen(names->rw, H5F_ACC_RDWR, fapl_id)) < 0)
            TEST_ERROR;
    }
    if (pass)
        validate_zoo(file_id, grp_name, 0); /* sanity-check */

    if (!pass) {
        printf("%s", failure_mssg);
        TEST_ERROR;
    }

    /* Cleanup */

    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;
    if (H5Gclose(grp_id) < 0)
        TEST_ERROR;
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Verify that the R/W and W/O files are identical */

    if (h5_compare_file_bytes(names->rw, names->wo) < 0)
        TEST_ERROR;

    free(names);

    PASSED();
    return 0;

error:
    free(names);
    H5E_BEGIN_TRY
    {
        H5Fclose(file_id);
        H5Gclose(grp_id);
        H5Pclose(fapl_id);
    }
    H5E_END_TRY
    return -1;
} /* end test_on_disk_zoo() */

/* ---------------------------------------------------------------------------
 * Function:    test_vanishing_datasets
 *
 * Purpose:     Verify behavior when writing to a file where data is deleted.
 *
 *              Each dataset is populated with the value of its suffix
 *              (dset5 is all fives).
 *
 *              Opens 0..15 create one new dataset each, '/dset[i]'.
 *              Opens 3..18 delete '/dset[1-3]'
 *
 *              Should end with no data in file.
 *
 * Return:      Success:  0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_vanishing_datasets(const struct mt_opts *opts)
{
    struct mirrortest_filenames *names     = NULL;
    hid_t                        file_id   = H5I_INVALID_HID;
    hid_t                        fapl_id   = H5I_INVALID_HID;
    hid_t                        dset_id   = H5I_INVALID_HID;
    hid_t                        dspace_id = H5I_INVALID_HID;
    hsize_t                      dims[2]   = {DATABUFFER_SIZE, DATABUFFER_SIZE};
    H5G_info_t                   group_info;
    unsigned int                 i, j, k;
    const unsigned int           max_loops       = 20;
    const unsigned int           max_at_one_time = 3;
    struct {
        uint32_t arr[DATABUFFER_SIZE][DATABUFFER_SIZE];
    } *buf = NULL;

    TESTING("Vanishing Datasets");

    if (NULL == (names = malloc(sizeof(struct mirrortest_filenames))))
        TEST_ERROR;
    if (NULL == (buf = calloc(1, sizeof(*buf))))
        TEST_ERROR;

    /* -------------------- */
    /* Set up recurrent data (FAPL, dataspace) */

    /* Create FAPL for Splitter[sec2|mirror] */
    if ((fapl_id = create_mirroring_split_fapl("vanishing", names, opts)) < 0)
        TEST_ERROR;

    if ((dspace_id = H5Screate_simple(2, dims, NULL)) < 0)
        TEST_ERROR;

    /* Create file */
    if ((file_id = H5Fcreate(names->rw, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
        TEST_ERROR;

    for (i = 0; i < max_loops; i++) {
        char namebuf[DSET_NAME_LEN + 1];

        /* Delete datasets */
        if (i >= max_at_one_time) {
            if (snprintf(namebuf, DSET_NAME_LEN, "/dset%02d", (i - max_at_one_time)) > DSET_NAME_LEN)
                TEST_ERROR;
            if (H5Ldelete(file_id, namebuf, H5P_DEFAULT) < 0)
                TEST_ERROR;
        }

        /* Write to datasets */
        if (i < (max_loops - max_at_one_time)) {
            if (snprintf(namebuf, DSET_NAME_LEN, "/dset%02d", i) > DSET_NAME_LEN)
                TEST_ERROR;
            if ((dset_id = H5Dcreate2(file_id, namebuf, H5T_STD_U32LE, dspace_id, H5P_DEFAULT, H5P_DEFAULT,
                                      H5P_DEFAULT)) < 0)
                TEST_ERROR;

            for (j = 0; j < DATABUFFER_SIZE; j++)
                for (k = 0; k < DATABUFFER_SIZE; k++)
                    buf->arr[j][k] = (uint32_t)i;

            if (H5Dwrite(dset_id, H5T_STD_U32LE, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
                TEST_ERROR;

            if (H5Dclose(dset_id) < 0)
                TEST_ERROR;
        }

    } /* end for dataset create-destroy cycles */

    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    /* verify there are no datasets in file */
    if ((file_id = H5Fopen(names->rw, H5F_ACC_RDONLY, fapl_id)) < 0)
        TEST_ERROR;
    if (H5Gget_info(file_id, &group_info) < 0)
        TEST_ERROR;
    if (group_info.nlinks > 0) {
        fprintf(stderr, "links in rw file: %" PRIuHSIZE "\n", group_info.nlinks);
        TEST_ERROR;
    }
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;
    if ((file_id = H5Fopen(names->wo, H5F_ACC_RDONLY, fapl_id)) < 0)
        TEST_ERROR;
    if (H5Gget_info(file_id, &group_info) < 0)
        TEST_ERROR;
    if (group_info.nlinks > 0) {
        fprintf(stderr, "links in wo file: %" PRIuHSIZE "\n", group_info.nlinks);
        TEST_ERROR;
    }
    if (H5Fclose(file_id) < 0)
        TEST_ERROR;

    if (h5_compare_file_bytes(names->rw, names->wo) < 0)
        TEST_ERROR;

    /* Teardown */

    if (H5Sclose(dspace_id) < 0)
        TEST_ERROR;
    if (H5Pclose(fapl_id) < 0)
        TEST_ERROR;

    free(names);
    free(buf);

    PASSED();
    return 0;

error:
    free(names);
    free(buf);
    H5E_BEGIN_TRY
    {
        H5Pclose(fapl_id);
        H5Fclose(file_id);
        H5Dclose(dset_id);
        H5Sclose(dspace_id);
    }
    H5E_END_TRY
    return -1;
} /* test_vanishing_datasets() */

/* ---------------------------------------------------------------------------
 * Function:    test_concurrent_access
 *
 * Purpose:     Verify that more than one file may be opened at a time.
 *
 *              TODO: receive target IP from caller?
 *
 * Return:      Success: 0
 *              Failure: -1
 * ---------------------------------------------------------------------------
 */
static int
test_concurrent_access(const struct mt_opts *opts)
{
    struct file_bundle {
        struct mirrortest_filenames names;
        hid_t                       dset_id;
        hid_t                       fapl_id;
        hid_t                       file_id;
    };

    struct file_bundle *bundle = NULL;

    hid_t   dspace_id = H5I_INVALID_HID;
    hid_t   dtype_id  = H5T_NATIVE_INT;
    hsize_t dims[2]   = {DATABUFFER_SIZE, DATABUFFER_SIZE};
    int    *buf       = NULL;
    int     i         = 0;
    int     j         = 0;

    TESTING("Concurrent opened mirrored files");

    if (NULL == (bundle = malloc(sizeof(struct file_bundle) * CONCURRENT_COUNT)))
        TEST_ERROR;

    /* Initialize bundle */
    for (i = 0; i < CONCURRENT_COUNT; i++) {
        bundle[i].dset_id    = H5I_INVALID_HID;
        bundle[i].fapl_id    = H5I_INVALID_HID;
        bundle[i].file_id    = H5I_INVALID_HID;
        *bundle[i].names.rw  = '\0';
        *bundle[i].names.wo  = '\0';
        *bundle[i].names.log = '\0';
    }

    /* Create FAPL for Splitter[sec2|mirror] */
    for (i = 0; i < CONCURRENT_COUNT; i++) {
        char  name[16] = "";
        hid_t fapl_id  = H5I_INVALID_HID;

        snprintf(name, 15, "concurrent%d", i);
        if ((fapl_id = create_mirroring_split_fapl(name, &bundle[i].names, opts)) < 0)
            TEST_ERROR;
        bundle[i].fapl_id = fapl_id;
    }

    /* Prepare data to be written */
    if (NULL == (buf = malloc(DATABUFFER_SIZE * DATABUFFER_SIZE * sizeof(int))))
        TEST_ERROR;
    for (i = 0; i < DATABUFFER_SIZE; i++) {
        for (j = 0; j < DATABUFFER_SIZE; j++) {
            int k  = i * DATABUFFER_SIZE + j;
            buf[k] = k;
        }
    }

    /* Prepare generic dataspace */
    if ((dspace_id = H5Screate_simple(2, dims, NULL)) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Create file and open elements */

    for (i = 0; i < CONCURRENT_COUNT; i++) {
        hid_t file_id = H5I_INVALID_HID;
        hid_t dset_id = H5I_INVALID_HID;

        if ((file_id = H5Fcreate(bundle[i].names.rw, H5F_ACC_TRUNC, H5P_DEFAULT, bundle[i].fapl_id)) < 0)
            TEST_ERROR;

        bundle[i].file_id = file_id;

        if ((dset_id = H5Dcreate2(file_id, "dataset", dtype_id, dspace_id, H5P_DEFAULT, H5P_DEFAULT,
                                  H5P_DEFAULT)) < 0)
            TEST_ERROR;
        bundle[i].dset_id = dset_id;
    }

    /* -------------------- */
    /* TEST: Write to files */

    for (i = 0; i < CONCURRENT_COUNT; i++)
        if (H5Dwrite(bundle[i].dset_id, dtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
            TEST_ERROR;

    /* -------------------- */
    /* TEST: Close elements  */

    for (i = 0; i < CONCURRENT_COUNT; i++) {
        if (H5Dclose(bundle[i].dset_id) < 0)
            TEST_ERROR;
        if (H5Fclose(bundle[i].file_id) < 0)
            TEST_ERROR;
        if (H5Pclose(bundle[i].fapl_id) < 0)
            TEST_ERROR;
    }

    if (H5Sclose(dspace_id) < 0)
        TEST_ERROR;

    /* -------------------- */
    /* TEST: Verify that the R/W and W/O files are identical */

    for (i = 0; i < CONCURRENT_COUNT; i++)
        if (h5_compare_file_bytes(bundle[i].names.rw, bundle[i].names.wo) < 0)
            TEST_ERROR;

    free(bundle);
    free(buf);

    PASSED();
    return 0;

error:
    H5E_BEGIN_TRY
    {
        H5Sclose(dspace_id);
        for (i = 0; i < CONCURRENT_COUNT; i++) {
            H5Dclose(bundle[i].dset_id);
            H5Fclose(bundle[i].file_id);
            H5Pclose(bundle[i].fapl_id);
        }
    }
    H5E_END_TRY
    free(bundle);
    free(buf);
    return -1;
} /* end test_concurrent_access() */

/* ----------------------------------------------------------------------------
 * Function:    parse_args
 *
 * Purpose:     Parse command-line arguments, populating the options struct
 *              pointer as appropriate.
 *              Default values will be set for unspecified options.
 *
 * Return:      0 on success, negative (-1) if error.
 * ----------------------------------------------------------------------------
 */
static int
parse_args(int argc, char **argv, struct mt_opts *opts)
{
    int i = 0;

    opts->portno = SERVER_HANDSHAKE_PORT;
    strncpy(opts->ip, SERVER_IP_ADDRESS, H5FD_MIRROR_MAX_IP_LEN);

    for (i = 1; i < argc; i++) { /* start with first possible option argument */
        if (!strncmp(argv[i], "--ip=", 5))
            strncpy(opts->ip, argv[i] + 5, H5FD_MIRROR_MAX_IP_LEN);
        else if (!strncmp(argv[i], "--port=", 7))
            opts->portno = atoi(argv[i] + 7);
        else {
            printf("Unrecognized option: '%s'\n", argv[i]);
            return -1;
        }
    } /* end for each argument from command line */

    /* Auto-replace 'localhost' with numeric IP */
    if (!strncmp(opts->ip, "localhost", 10)) /* include NUL terminator */
        strncpy(opts->ip, "127.0.0.1", H5FD_MIRROR_MAX_IP_LEN);

    return 0;
} /* end parse_args() */

/* ----------------------------------------------------------------------------
 * Function:    confirm_server
 *
 * Purpose:     Create socket and confirm remote server is available.
 *
 * Return:      0 on success, negative (-1) if error.
 * ----------------------------------------------------------------------------
 */
static int
confirm_server(struct mt_opts *opts)
{
    char               mybuf[16];
    int                live_socket = -1;
    struct sockaddr_in target_addr;
    unsigned           attempt = 0;

    live_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (live_socket < 0) {
        printf("ERROR socket()\n");
        return -1;
    }

    target_addr.sin_family      = AF_INET;
    target_addr.sin_port        = htons((uint16_t)opts->portno);
    target_addr.sin_addr.s_addr = inet_addr(opts->ip);
    memset(target_addr.sin_zero, '\0', sizeof(target_addr.sin_zero));

    while (1) {
        if (connect(live_socket, (struct sockaddr *)&target_addr, (socklen_t)sizeof(target_addr)) < 0) {
            if (attempt > 10) {
                printf("ERROR connect() (%d)\n%s\n", errno, strerror(errno));
                return -1;
            }

            /* Close socket during sleep() */
            if (HDclose(live_socket) < 0) {
                printf("ERROR close() can't close socket\n");
                return -1;
            }
            live_socket = -1;

            attempt++;
            HDsleep(1);
            printf("attempt #%u: ERROR connect() (%d)\n%s\n", attempt, errno, strerror(errno));

            /* Re-open socket for retry */
            live_socket = socket(AF_INET, SOCK_STREAM, 0);
            if (live_socket < 0) {
                printf("ERROR socket()\n");
                return -1;
            }
        }
        else
            break;
    }

    /* Request confirmation from the server */
    if (HDwrite(live_socket, "CONFIRM", 8) == -1) {
        printf("ERROR write() (%d)\n%s\n", errno, strerror(errno));
        return -1;
    }

    /* Read & verify response from port connection.  */
    if (HDread(live_socket, &mybuf, sizeof(mybuf)) == -1) {
        printf("ERROR read() can't receive data\n");
        return -1;
    }
    if (strncmp("ALIVE", mybuf, 6)) {
        printf("ERROR read() didn't receive data from server\n");
        return -1;
    }

    if (HDclose(live_socket) < 0) {
        printf("ERROR close() can't close socket\n");
        return -1;
    }

    return 0;
} /* end confirm_server() */

/* ---------------------------------------------------------------------------
 * Function:    main
 *
 * Purpose:     Run tests
 *
 * Return:      Success: 0
 *              Failure: 1
 * ---------------------------------------------------------------------------
 */
int
main(int argc, char **argv)
{
    struct mt_opts opts;
    int            nerrors = 0;

    h5_reset();

    g_log_stream = stdout; /* default debug/logging output stream */

    printf("Testing Mirror VFD functionality.\n");

    /* SETUP */

    /* Create directories for test-generated .h5 files */
    if (nerrors == 0) {
        if ((HDmkdir(MIRROR_RW_DIR, (mode_t)0755) < 0) && (errno != EEXIST))
            nerrors++;
    }
    if (nerrors == 0) {
        if ((HDmkdir(MIRROR_WO_DIR, (mode_t)0755) < 0) && (errno != EEXIST))
            nerrors++;
    }

    if (parse_args(argc, argv, &opts) < 0) {
        printf("Unable to parse arguments\n");
        exit(EXIT_FAILURE);
    }

    if (confirm_server(&opts) < 0) {
        printf("Unable to confirm server is running\n");
        exit(EXIT_FAILURE);
    }

    /* TESTS */

    if (nerrors == 0) {
        H5FD_mirror_xmit_t xmit_mock; /* Re-used header in various xmit tests */

        /* Set bogus values matching expected; encoding doesn't care
         * Use sequential values to easily generate the expected buffer with a
         * for loop.
         */
        xmit_mock.magic         = 0x00010203;
        xmit_mock.version       = 0x04;
        xmit_mock.session_token = 0x05060708;
        xmit_mock.xmit_count    = 0x090A0B0C;
        xmit_mock.op            = 0x0D;

        nerrors += test_fapl_configuration() < 0 ? 1 : 0;

        nerrors += test_encdec_uint8_t() < 0 ? 1 : 0;
        nerrors += test_encdec_uint16_t() < 0 ? 1 : 0;
        nerrors += test_encdec_uint32_t() < 0 ? 1 : 0;
        nerrors += test_encdec_uint64_t() < 0 ? 1 : 0;

        nerrors += test_encdec_header(xmit_mock) < 0 ? 1 : 0;
        nerrors += test_encdec_set_eoa(xmit_mock) < 0 ? 1 : 0;
        nerrors += test_encdec_lock(xmit_mock) < 0 ? 1 : 0;
        nerrors += test_encdec_open(xmit_mock) < 0 ? 1 : 0;
        nerrors += test_encdec_reply(xmit_mock) < 0 ? 1 : 0;
        nerrors += test_encdec_write(xmit_mock) < 0 ? 1 : 0;

        nerrors += test_create_and_close(&opts) < 0 ? 1 : 0;
        nerrors += test_basic_dataset_write(&opts) < 0 ? 1 : 0;
        nerrors += test_chunked_dataset_write(&opts) < 0 ? 1 : 0;
        nerrors += test_on_disk_zoo(&opts) < 0 ? 1 : 0;
        nerrors += test_vanishing_datasets(&opts) < 0 ? 1 : 0;
        nerrors += test_concurrent_access(&opts) < 0 ? 1 : 0;
    }

    if (nerrors) {
        printf("***** %d Mirror VFD TEST%s FAILED! *****\n", nerrors, nerrors > 1 ? "S" : "");
        return EXIT_FAILURE;
    }

    printf("All Mirror Virtual File Driver tests passed.\n");
    return EXIT_SUCCESS;
} /* end main() */

#else /* H5_HAVE_MIRROR_VFD */

int
main(void)
{
    printf("Testing Mirror VFD functionality.\n");
    printf("SKIPPED - Mirror VFD not built.\n");
    return EXIT_SUCCESS;
}

#endif /* H5_HAVE_MIRROR_VFD */