summaryrefslogtreecommitdiffstats
path: root/testpar/t_mdset.c
blob: 1272e424b842760b72e537b178045dbd42cfb3fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
/* $Id$ */

#include "testphdf5.h"

#define DIM  2
#define SIZE 32
#define NDATASET 4
#define GROUP_DEPTH 128
enum obj_type { is_group, is_dset };
 
void write_dataset(hid_t, hid_t, hid_t);
int  read_dataset(hid_t, hid_t, hid_t);
void create_group_recursive(hid_t, hid_t, hid_t, int);
void recursive_read_group(hid_t, hid_t, hid_t, int);
void write_attribute(hid_t, int, int);
int  read_attribute(hid_t, int, int);
int  check_value(DATATYPE *, DATATYPE *);
void get_slab(hssize_t[], hsize_t[], hsize_t[], hsize_t[]);

/*
 * Example of using PHDF5 to create ndatasets datasets.  Each process write
 * a slab of array to the file.
 */
void multiple_dset_write(char *filename, int ndatasets)
{
    int i, j, n, mpi_size, mpi_rank;
    hid_t iof, plist, dataset, memspace, filespace;
    hid_t dcpl;                         /* Dataset creation property list */
    hssize_t chunk_origin [DIM];
    hsize_t chunk_dims [DIM], file_dims [DIM];
    hsize_t count[DIM]={1,1};
    double outme [SIZE][SIZE];
    double fill=1.0;                    /* Fill value */
    char dname [100];
    herr_t ret;

    MPI_Comm_rank (MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size (MPI_COMM_WORLD, &mpi_size);

    VRFY((mpi_size <= SIZE), "mpi_size <= SIZE");

    chunk_origin [0] = mpi_rank * (SIZE / mpi_size);
    chunk_origin [1] = 0;
    chunk_dims [0] = SIZE / mpi_size;
    chunk_dims [1] = SIZE;

    for (i = 0; i < DIM; i++)
	file_dims [i] = SIZE;

    plist = create_faccess_plist(MPI_COMM_WORLD, MPI_INFO_NULL, facc_type);
    iof = H5Fcreate (filename, H5F_ACC_TRUNC, H5P_DEFAULT, plist);
    H5Pclose (plist);

    memspace = H5Screate_simple (DIM, chunk_dims, NULL);
    filespace = H5Screate_simple (DIM, file_dims, NULL);
    ret = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, chunk_origin, chunk_dims, count, chunk_dims);
    VRFY((ret>=0), "mdata hyperslab selection");

    /* Create a dataset creation property list */
    dcpl = H5Pcreate(H5P_DATASET_CREATE);
    VRFY((dcpl>=0), "dataset creation property list succeeded");

    ret=H5Pset_fill_value(dcpl, H5T_NATIVE_DOUBLE, &fill);
    VRFY((ret>=0), "set fill-value succeeded");

    for (n = 0; n < ndatasets; n++) {
	sprintf (dname, "dataset %d", n);
	dataset = H5Dcreate (iof, dname, H5T_NATIVE_DOUBLE, filespace, dcpl);
	VRFY((dataset > 0), dname); 

	/* calculate data to write */
	for (i = 0; i < SIZE; i++)
	    for (j = 0; j < SIZE; j++)
	        outme [i][j] = n*1000 + mpi_rank;

	H5Dwrite (dataset, H5T_NATIVE_DOUBLE, memspace, filespace, H5P_DEFAULT, outme);

	H5Dclose (dataset);
#ifdef BARRIER_CHECKS
	if (! ((n+1) % 10)) {
	    printf("created %d datasets\n", n+1);
	    MPI_Barrier(MPI_COMM_WORLD);
	}
#endif /* BARRIER_CHECKS */
    }

    H5Sclose (filespace);
    H5Sclose (memspace);
    H5Pclose (dcpl);
    H5Fclose (iof);
}

/* Example of using PHDF5 to create, write, and read compact dataset.  
 * Hyperslab is prohibited for write.
 */
void compact_dataset(char *filename)
{
    int i, j, mpi_size, mpi_rank, err_num=0;
    hid_t iof, plist, dcpl, dxpl, dataset, memspace, filespace;
    hssize_t chunk_origin [DIM];
    hsize_t chunk_dims [DIM], file_dims [DIM];
    hsize_t count[DIM]={1,1};
    double outme [SIZE][SIZE], inme[SIZE][SIZE];
    char dname[]="dataset";
    herr_t ret;
                                
    MPI_Comm_rank (MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size (MPI_COMM_WORLD, &mpi_size);

    VRFY((mpi_size <= SIZE), "mpi_size <= SIZE");

    chunk_origin [0] = mpi_rank * (SIZE / mpi_size);
    chunk_origin [1] = 0;
    chunk_dims [0] = SIZE / mpi_size;
    chunk_dims [1] = SIZE;

    for (i = 0; i < DIM; i++)
         file_dims [i] = SIZE;

    plist = create_faccess_plist(MPI_COMM_WORLD, MPI_INFO_NULL, facc_type);
    iof = H5Fcreate (filename, H5F_ACC_TRUNC, H5P_DEFAULT, plist);

    /* Define data space */
    memspace = H5Screate_simple (DIM, chunk_dims, NULL);
    filespace = H5Screate_simple (DIM, file_dims, NULL);

    /* Create a compact dataset */
    dcpl = H5Pcreate(H5P_DATASET_CREATE);
    VRFY((dcpl>=0), "dataset creation property list succeeded");
    ret=H5Pset_layout(dcpl, H5D_COMPACT);
    VRFY((dcpl >= 0), "set property list for compact dataset");
    ret=H5Pset_space_time(dcpl, H5D_SPACE_ALLOC_EARLY);
    VRFY((ret >= 0), "set space allocation time for compact dataset");

    dataset = H5Dcreate (iof, dname, H5T_NATIVE_DOUBLE, filespace, dcpl);
    VRFY((dataset >= 0), "H5Dcreate succeeded");        

    /* Define hyperslab */
    ret = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, chunk_origin, chunk_dims, count, chunk_dims);    
    VRFY((ret>=0), "mdata hyperslab selection");
    
    /* set up the collective transfer properties list */
    dxpl = H5Pcreate (H5P_DATASET_XFER);
    VRFY((dxpl >= 0), "");
    ret=H5Pset_dxpl_mpio(dxpl, H5FD_MPIO_COLLECTIVE);
    VRFY((ret >= 0), "H5Pcreate xfer succeeded");

    /* calculate data to write */
    for (i = 0; i < SIZE; i++)
         for (j = 0; j < SIZE; j++)
              outme [i][j] = (i+j)*1000 + mpi_rank;

    /* Test hyperslab writing.  Supposed to fail */
    H5E_BEGIN_TRY {
        ret=H5Dwrite(dataset, H5T_NATIVE_DOUBLE, memspace, filespace, dxpl, outme);
    } H5E_END_TRY;
    VRFY((ret < 0), "H5Dwrite hyperslab write failed as expected");

    /* Recalculate data to write.  Each process writes the same data. */
    for (i = 0; i < SIZE; i++)
         for (j = 0; j < SIZE; j++)
              outme [i][j] = (i+j)*1000;

    ret=H5Dwrite (dataset, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, dxpl, outme);
    VRFY((ret >= 0), "H5Dwrite succeeded");

    H5Pclose (dcpl);
    H5Pclose (plist);
    H5Dclose (dataset);
    H5Sclose (filespace);
    H5Sclose (memspace);
    H5Fclose (iof);

    /* Open the file and dataset, read and compare the data. */
    plist = create_faccess_plist(MPI_COMM_WORLD, MPI_INFO_NULL, facc_type);
    iof = H5Fopen(filename, H5F_ACC_RDONLY, plist);
    VRFY((iof >= 0), "H5Fopen succeeded");

    /* set up the collective transfer properties list */
    dxpl = H5Pcreate (H5P_DATASET_XFER);
    VRFY((dxpl >= 0), "");
    ret=H5Pset_dxpl_mpio(dxpl, H5FD_MPIO_COLLECTIVE);
    VRFY((ret >= 0), "H5Pcreate xfer succeeded");

    dataset = H5Dopen(iof, dname);
    VRFY((dataset >= 0), "H5Dcreate succeeded");

    ret = H5Dread(dataset, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, dxpl, inme);
    VRFY((ret >= 0), "H5Dread succeeded");

    /* Verify data value */
    for (i = 0; i < SIZE; i++)
        for (j = 0; j < SIZE; j++)
            if(inme[i][j] != outme[i][j])
                if(err_num++ < MAX_ERR_REPORT || verbose)
                    printf("Dataset Verify failed at [%d][%d]: expect %f, got %f\n", i, j, outme[i][j], inme[i][j]); 
                                                            
    H5Pclose(plist);
    H5Pclose(dxpl);
    H5Dclose(dataset);
    H5Fclose(iof);
}

/*
 * Example of using PHDF5 to create multiple groups.  Under the root group, 
 * it creates ngroups groups.  Under the first group just created, it creates 
 * recursive subgroups of depth GROUP_DEPTH.  In each created group, it 
 * generates NDATASETS datasets.  Each process write a hyperslab of an array
 * into the file.  The structure is like
 *               
 *                             root group
 *                                 |
 *            ---------------------------- ... ... ------------------------
 *           |          |         |        ... ...  |                      |
 *       group0*+'   group1*+' group2*+'   ... ...             group ngroups*+'
 *           |
 *      1st_child_group*' 
 *           |
 *      2nd_child_group*'
 *           |
 *           :
 *           :
 *           |
 * GROUP_DEPTHth_child_group*'
 *
 *      * means the group has dataset(s).
 *      + means the group has attribute(s).
 *      ' means the datasets in the groups have attribute(s).
 */
void multiple_group_write(char *filename, int ngroups)
{
    int mpi_rank, mpi_size;
    int m;
    char gname[64];
    hid_t fid, gid, plist, memspace, filespace;
    hssize_t chunk_origin[DIM];
    hsize_t chunk_dims[DIM], file_dims[DIM], count[DIM];
    herr_t ret1, ret2;

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);

    plist = create_faccess_plist(MPI_COMM_WORLD, MPI_INFO_NULL, facc_type);
    fid = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, plist);
    H5Pclose(plist);

    /* decide the hyperslab according to process number. */
    get_slab(chunk_origin, chunk_dims, count, file_dims);  

    /* select hyperslab in memory and file spaces.  These two operations are
     * identical since the datasets are the same. */
    memspace  = H5Screate_simple(DIM, file_dims, NULL);
    ret1 = H5Sselect_hyperslab(memspace, H5S_SELECT_SET, chunk_origin, 
                               chunk_dims, count, chunk_dims);
    filespace = H5Screate_simple(DIM, file_dims,  NULL);
    ret2 = H5Sselect_hyperslab(filespace, H5S_SELECT_SET, chunk_origin, 
                               chunk_dims, count, chunk_dims);
    VRFY((memspace>=0), "memspace");
    VRFY((filespace>=0), "filespace");
    VRFY((ret1>=0), "mgroup memspace selection");
    VRFY((ret2>=0), "mgroup filespace selection");   

    /* creates ngroups groups under the root group, writes datasets in 
     * parallel. */
    for(m = 0; m < ngroups; m++) {
        sprintf(gname, "group%d", m);
        gid = H5Gcreate(fid, gname, 0);
        VRFY((gid > 0), gname);

        /* create attribute for these groups. */   
	write_attribute(gid, is_group, m);
           
        if(m != 0)
	    write_dataset(memspace, filespace, gid);

        H5Gclose(gid);

#ifdef BARRIER_CHECKS
        if(! ((m+1) % 10)) {
            printf("created %d groups\n", m+1);
            MPI_Barrier(MPI_COMM_WORLD);
	}
#endif /* BARRIER_CHECKS */
    }
    
    /* recursively creates subgroups under the first group. */
    gid = H5Gopen(fid, "group0");
    create_group_recursive(memspace, filespace, gid, 0);
    H5Gclose(gid);
    
    H5Sclose(filespace);
    H5Sclose(memspace);
    H5Fclose(fid);
}

/* 
 * In a group, creates NDATASETS datasets.  Each process writes a hyperslab
 * of a data array to the file.
 */ 
void write_dataset(hid_t memspace, hid_t filespace, hid_t gid)
{
    int i, j, n;
    int mpi_rank, mpi_size;
    char dname[32];
    DATATYPE outme[SIZE][SIZE];
    hid_t did;

  
    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);

    for(n=0; n < NDATASET; n++) {
         sprintf(dname, "dataset%d", n);
         did = H5Dcreate(gid, dname, H5T_NATIVE_INT, filespace, 
                         H5P_DEFAULT);
         VRFY((did > 0), dname);

         for(i=0; i < SIZE; i++)
             for(j=0; j < SIZE; j++)
     	         outme[i][j] = n*1000 + mpi_rank;

         H5Dwrite(did, H5T_NATIVE_INT, memspace, filespace, H5P_DEFAULT, 
                  outme);

         /* create attribute for these datasets.*/
         write_attribute(did, is_dset, n);
	 
         H5Dclose(did);
    }
}

/* 
 * Creates subgroups of depth GROUP_DEPTH recursively.  Also writes datasets
 * in parallel in each group.
 */
void create_group_recursive(hid_t memspace, hid_t filespace, hid_t gid, 
                            int counter)
{ 
   hid_t child_gid;
   int   mpi_rank;
   char  gname[64];
  
   MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);

#ifdef BARRIER_CHECKS
   if(! ((counter+1) % 10)) {
        printf("created %dth child groups\n", counter+1);
        MPI_Barrier(MPI_COMM_WORLD);
   }
#endif /* BARRIER_CHECKS */
 
   sprintf(gname, "%dth_child_group", counter+1);   
   child_gid = H5Gcreate(gid, gname, 0);
   VRFY((child_gid > 0), gname);

   /* write datasets in parallel. */
   write_dataset(memspace, filespace, gid);  

   if( counter < GROUP_DEPTH ) 
       create_group_recursive(memspace, filespace, child_gid, counter+1);

   H5Gclose(child_gid);
}

/* 
 * This function is to verify the data from multiple group testing.  It opens
 * every dataset in every group and check their correctness.  
 */
void multiple_group_read(char *filename, int ngroups)
{
    int      mpi_rank, mpi_size, error_num;
    int      m;
    char     gname[64];
    hid_t    plist, fid, gid, memspace, filespace;
    hssize_t chunk_origin[DIM];
    hsize_t  chunk_dims[DIM], file_dims[DIM], count[DIM];

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);

    plist = create_faccess_plist(MPI_COMM_WORLD, MPI_INFO_NULL, facc_type);
    fid = H5Fopen(filename, H5F_ACC_RDONLY, plist);
    H5Pclose(plist);

    /* decide hyperslab for each process */
    get_slab(chunk_origin, chunk_dims, count, file_dims);

    /* select hyperslab for memory and file space */
    memspace  = H5Screate_simple(DIM, file_dims, NULL);
    H5Sselect_hyperslab(memspace, H5S_SELECT_SET, chunk_origin, chunk_dims,
                        count, chunk_dims);
    filespace = H5Screate_simple(DIM, file_dims, NULL);
    H5Sselect_hyperslab(filespace, H5S_SELECT_SET, chunk_origin, chunk_dims, 
                        count, chunk_dims);
    
    /* open every group under root group. */
    for(m=0; m<ngroups; m++) {
        sprintf(gname, "group%d", m);
        gid = H5Gopen(fid, gname);
        VRFY((gid > 0), gname);
         
        /* check the data. */
        if(m != 0)
            if( (error_num = read_dataset(memspace, filespace, gid))>0)
	        nerrors += error_num;
        
        /* check attribute.*/ 
        error_num = 0;        
        if( (error_num = read_attribute(gid, is_group, m))>0 )
	    nerrors += error_num;

        H5Gclose(gid);

#ifdef BARRIER_CHECKS
        if(!((m+1)%10))
            MPI_Barrier(MPI_COMM_WORLD);
#endif /* BARRIER_CHECKS */
    }

    /* open all the groups in vertical direction. */
    gid = H5Gopen(fid, "group0");
    VRFY((gid>0), "group0");
    recursive_read_group(memspace, filespace, gid, 0);
    H5Gclose(gid);

    H5Sclose(filespace);
    H5Sclose(memspace);
    H5Fclose(fid);

}

/* 
 * This function opens all the datasets in a certain, checks the data using 
 * dataset_vrfy function.
 */
int read_dataset(hid_t memspace, hid_t filespace, hid_t gid)
{
    int i, j, n, mpi_rank, mpi_size, attr_errors=0, vrfy_errors=0;
    char dname[32];
    DATATYPE *outdata, *indata;
    hid_t did;

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);

    indata = (DATATYPE*)malloc(SIZE*SIZE*sizeof(DATATYPE));
    outdata = (DATATYPE*)malloc(SIZE*SIZE*sizeof(DATATYPE));

    for(n=0; n<NDATASET; n++) {
        sprintf(dname, "dataset%d", n);
        did = H5Dopen(gid, dname);
        VRFY((did>0), dname);

        H5Dread(did, H5T_NATIVE_INT, memspace, filespace, H5P_DEFAULT, 
                indata);

        /* this is the original value */
        for(i=0; i<SIZE; i++)
	    for(j=0; j<SIZE; j++) { 
	         *outdata = n*1000 + mpi_rank;
                 outdata++;
	    }
        outdata -= SIZE*SIZE;

        /* compare the original value(outdata) to the value in file(indata).*/
        vrfy_errors = check_value(indata, outdata);

        /* check attribute.*/  
        if( (attr_errors = read_attribute(did, is_dset, n))>0 )
            vrfy_errors += attr_errors; 
	       
        H5Dclose(did);
    }

    free(indata);
    free(outdata);

    return vrfy_errors;
}

/* 
 * This recursive function opens all the groups in vertical direction and 
 * checks the data.
 */
void recursive_read_group(hid_t memspace, hid_t filespace, hid_t gid, 
                          int counter)
{
    hid_t child_gid;
    int   mpi_rank, err_num=0;
    char  gname[64];

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
#ifdef BARRIER_CHECKS
    if((counter+1) % 10) 
        MPI_Barrier(MPI_COMM_WORLD);
#endif /* BARRIER_CHECKS */

    if( (err_num = read_dataset(memspace, filespace, gid)) )
        nerrors += err_num;

    if( counter < GROUP_DEPTH ) {
        sprintf(gname, "%dth_child_group", counter+1);
        child_gid = H5Gopen(gid, gname);
        VRFY((child_gid>0), gname);
        recursive_read_group(memspace, filespace, child_gid, counter+1);
        H5Gclose(child_gid);
    }
}

/* Create and write attribute for a group or a dataset.  For groups, attribute
 * is a scalar datum; for dataset, it is a one-dimensional array.
 */ 
void write_attribute(hid_t obj_id, int this_type, int num)
{
    hid_t   sid, aid;
    hsize_t dspace_dims[1]={8};
    int     i, mpi_rank, attr_data[8], dspace_rank=1;
    char    attr_name[32];

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
        
    if(this_type == is_group) {
        sprintf(attr_name, "Group Attribute %d", num);
        sid = H5Screate(H5S_SCALAR);
        aid = H5Acreate(obj_id, attr_name, H5T_NATIVE_INT, sid, H5P_DEFAULT);
        H5Awrite(aid, H5T_NATIVE_INT,  &num);
        H5Aclose(aid);
        H5Sclose(sid);
    }
    else if(this_type == is_dset) {
        sprintf(attr_name, "Dataset Attribute %d", num);
        for(i=0; i<8; i++)
            attr_data[i] = i;
        sid = H5Screate_simple(dspace_rank, dspace_dims, NULL);
        aid = H5Acreate(obj_id, attr_name, H5T_NATIVE_INT, sid, H5P_DEFAULT);
        H5Awrite(aid, H5T_NATIVE_INT, attr_data);   
        H5Aclose(aid);
        H5Sclose(sid);
    }

}

/* Read and verify attribute for group or dataset. */
int read_attribute(hid_t obj_id, int this_type, int num)
{
    hid_t aid;
    hsize_t group_block[2]={1,1}, dset_block[2]={1, 8};
    int  i, mpi_rank, in_num, in_data[8], out_data[8], vrfy_errors = 0;
    char attr_name[32];
   
    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    
    if(this_type == is_group) {
        sprintf(attr_name, "Group Attribute %d", num);
        aid = H5Aopen_name(obj_id, attr_name);
        if(MAINPROCESS) {
            H5Aread(aid, H5T_NATIVE_INT, &in_num);
            vrfy_errors =  dataset_vrfy(NULL, NULL, NULL, group_block, 
                                        &in_num, &num);
	}
        H5Aclose(aid);
    }
    else if(this_type == is_dset) {
        sprintf(attr_name, "Dataset Attribute %d", num);  
        for(i=0; i<8; i++)
            out_data[i] = i;
        aid = H5Aopen_name(obj_id, attr_name);
        if(MAINPROCESS) {
            H5Aread(aid, H5T_NATIVE_INT, in_data);
            vrfy_errors = dataset_vrfy(NULL, NULL, NULL, dset_block, in_data,
                                       out_data);
	}
        H5Aclose(aid);
    }       
    
    return vrfy_errors;
}

/* This functions compares the original data with the read-in data for its 
 * hyperslab part only by process ID. */
int check_value(DATATYPE *indata, DATATYPE *outdata) 
{
    int mpi_rank, mpi_size, err_num=0;
    hsize_t i, j;
    hssize_t chunk_origin[DIM];
    hsize_t  chunk_dims[DIM], count[DIM];

    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);
    
    get_slab(chunk_origin, chunk_dims, count, NULL);

    indata += chunk_origin[0]*SIZE;
    outdata += chunk_origin[0]*SIZE;
    for(i=chunk_origin[0]; i<(chunk_origin[0]+chunk_dims[0]); i++)
         for(j=chunk_origin[1]; j<(chunk_origin[1]+chunk_dims[1]); j++) {
              if( *indata != *outdata )
	          if(err_num++ < MAX_ERR_REPORT || verbose)
		      printf("Dataset Verify failed at [%ld][%ld](row %ld, col%ld): expect %d, got %d\n", (long)i, (long)j, (long)i, (long)j, *outdata, *indata); 
	 }
    if(err_num > MAX_ERR_REPORT && !verbose)
        printf("[more errors ...]\n");
    if(err_num)
        printf("%d errors found in check_value\n", err_num);
    return err_num;
}

/* Decide the portion of data chunk in dataset by process ID. */
void get_slab(hssize_t chunk_origin[], hsize_t chunk_dims[], hsize_t count[],
              hsize_t file_dims[])
{
    int mpi_rank, mpi_size;
    
    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);

    if(chunk_origin != NULL) {
        chunk_origin[0] = mpi_rank * (SIZE/mpi_size);
        chunk_origin[1] = 0;
    }
    if(chunk_dims != NULL) {
        chunk_dims[0]   = SIZE/mpi_size;
        chunk_dims[1]   = SIZE;
    }
    if(file_dims != NULL) 
        file_dims[0] = file_dims[1] = SIZE;
    if(count != NULL) 
        count[0] = count[1] = 1;
}

/*=============================================================================
 *                         End of t_mdset.c
 *===========================================================================*/