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
|
<html>
<head><title>
HDF5/H5E API Specification
</title></head>
<body bgcolor="#FFFFFF">
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="index.html">HDF5 documents and links</a> <br>
<a href="H5.intro.html">Introduction to HDF5</a> <br>
<a href="H5.user.html">HDF5 User's Guide</a> <br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
</td>
<td valign=top align=right>
And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>
<br>
<a href="RM_H5.html">H5</a>
<a href="RM_H5A.html">H5A</a>
<a href="RM_H5D.html">H5D</a>
H5E
<a href="RM_H5F.html">H5F</a>
<a href="RM_H5G.html">H5G</a>
<a href="RM_H5I.html">H5I</a>
<br>
<a href="RM_H5P.html">H5P</a>
<a href="RM_H5R.html">H5R</a>
<a href="RM_H5RA.html">H5RA</a>
<a href="RM_H5S.html">H5S</a>
<a href="RM_H5T.html">H5T</a>
<a href="RM_H5Z.html">H5Z</a>
<a href="Tools.html">Tools</a>
</td></tr>
</table>
</center>
<hr>
<center>
<h1>H5E: Error Interface</h1>
</center>
<h2>Error API Functions</h2>
These functions provide error handling capabilities in the HDF5 environment.
<table border=0>
<tr><td valign=top>
<ul>
<li><a href="#Error-SetAuto">H5Eset_auto</a>
<li><a href="#Error-GetAuto">H5Eget_auto</a>
<li><a href="#Error-Clear">H5Eclear</a>
</ul>
</td><td> </td><td valign=top>
<ul>
<li><a href="#Error-Print">H5Eprint</a>
<li><a href="#Error-Walk">H5Ewalk</a>
<li><a href="#Error-WalkCB">H5Ewalk_cb</a>
</ul>
</td><td> </td><td valign=top>
<ul>
<li><a href="#Error-GetMajor">H5Eget_major</a>
<li><a href="#Error-GetMinor">H5Eget_minor</a>
</ul>
</td></tr>
</table>
<p>
The Error interface provides error handling in the form of a stack.
The <code>FUNC_ENTER()</code> macro clears the error stack whenever
an interface function is entered.
When an error is detected, an entry is pushed onto the stack.
As the functions unwind, additional entries are pushed onto the stack.
The API function will return some indication that an error occurred and
the application can print the error stack.
<p>
Certain API functions in the H5E package, such as <code>H5Eprint()</code>,
do not clear the error stack. Otherwise, any function which
does not have an underscore immediately after the package name
will clear the error stack. For instance, <code>H5Fopen()</code>
clears the error stack while <code>H5F_open()</code> does not.
<p>
An error stack has a fixed maximum size.
If this size is exceeded then the stack will be truncated and only the
inner-most functions will have entries on the stack.
This is expected to be a rare condition.
<p>
Each thread has its own error stack, but since
multi-threading has not been added to the library yet, this
package maintains a single error stack. The error stack is
statically allocated to reduce the complexity of handling
errors within the H5E package.
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-SetAuto">H5Eset_auto</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Eset_auto</code>(<em>H5E_auto_t</em> <code>func</code>,
<em>void *</em><code>client_data</code>
)
<dt><strong>Purpose:</strong>
<dd>Turns automatic error printing on or off.
<dt><strong>Description:</strong>
<dd><code>H5Eset_auto</code> turns on or off automatic printing of
errors. When turned on (non-null <code>func</code> pointer),
any API function which returns an error indication will
first call <code>func</code>, passing it <code>client_data</code>
as an argument.
<p>
When the library is first initialized the auto printing function
is set to <code>H5Eprint()</code> (cast appropriately) and
<code>client_data</code> is the standard error stream pointer,
<code>stderr</code>.
<p>
Automatic stack traversal is always in the
<code>H5E_WALK_DOWNWARD</code> direction.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5E_auto_t</em> <code>func</code>
<dd>Function to be called upon an error condition.
<dt><em>void *</em><code>client_data</code>
<dd>Data passed to the error function.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-GetAuto">H5Eget_auto</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Eget_auto</code>(<em>H5E_auto_t *</em> <code>func</code>,
<em>void **</em><code>client_data</code>
)
<dt><strong>Purpose:</strong>
<dd>Returns the current settings for the automatic error stack
traversal function and its data.
<dt><strong>Description:</strong>
<dd><code>H5Eget_auto</code> returns the current settings for the
automatic error stack traversal function, <code>func</code>,
and its data, <code>client_data</code>. Either (or both)
arguments may be null in which case the value is not returned.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5E_auto_t *</em> <code>func</code>
<dd>Current setting for the function to be called upon an
error condition.
<dt><em>void **</em><code>client_data</code>
<dd>Current setting for the data passed to the error function.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-Clear">H5Eclear</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Eclear</code>(<code>void</code>)
<dt><strong>Purpose:</strong>
<dd>Clears the error stack for the current thread.
<dt><strong>Description:</strong>
<dd><code>H5Eclear</code> clears the error stack for the current thread.
<p>
The stack is also cleared whenever an API function is called,
with certain exceptions (for instance, <code>H5Eprint()</code>).
<p>
<code>H5Eclear</code> can fail if there are problems initializing
the library.
<dt><strong>Parameters:</strong>
<dl>
<dt>None
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-Print">H5Eprint</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Eprint</code>(<em>FILE *</em> <code>stream</code>)
<dt><strong>Purpose:</strong>
<dd>Prints the error stack in a default manner.
<dt><strong>Description:</strong>
<dd><code>H5Eprint</code> prints the error stack on the specified
stream, <code>stream</code>.
Even if the error stack is empty, a one-line message will be printed:
<br>
<code>HDF5-DIAG: Error detected in thread 0.</code>
<p>
<code>H5Eprint</code> is a convenience function for
<code>H5Ewalk()</code> with a function that prints error messages.
Users are encouraged to write there own more specific error handlers.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>FILE *</em> <code>stream</code>
<dd>File pointer, or stderr if NULL.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-Walk">H5Ewalk</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Ewalk</code>(<em>H5E_direction_t</em> <code>direction</code>,
<em>H5E_walk_t</em> <code>func</code>,
<em>void *</em> <code>client_data</code>
)
<dt><strong>Purpose:</strong>
<dd>Walks the error stack for the current thread, calling a specified
function.
<dt><strong>Description:</strong>
<dd><code>H5Ewalk</code> walks the error stack for the current thread
and calls the specified function for each error along the way.
<p>
<code>direction</code> determines whether the stack is walked
from the inside out or the outside in.
A value of <code>H5E_WALK_UPWARD</code> means begin with the
most specific error and end at the API;
a value of <code>H5E_WALK_DOWNWARD</code> means to start at the
API and end at the inner-most function where the error was first
detected.
<p>
<code>func</code> will be called for each error in the error stack.
Its arguments will include an index number (beginning at zero
regardless of stack traversal direction), an error stack entry,
and the <code>client_data</code> pointer passed to
<code>H5E_print</code>.
The <code>H5E_walk_t</code> prototype is as follows:
<dir>
<p>
<code>typedef</code> <em>herr_t</em> <code>(*H5E_walk_t)(</code><em>int</em> <code>n,</code>
<em>H5E_error_t *</em><code>err_desc,</code>
<em>void *</em><code>client_data)</code>
<p>
where the parameters have the following meanings:
<dl>
<dt><em>int</em> <code>n</code>
<dd>Indexed position of the error in the stack.
<dt><em>H5E_error_t *</em><code>err_desc</code>
<dd>Pointer to a data structure describing the error.
<em>(This structure is currently described only in the
source code file </em><code>hdf5/src/H5Epublic.h</code><em>.
That file also contains the definitive list of major
and minor error codes. That information will
eventually be presented as an appendix to this
<cite>Reference Manual</cite>.)</em>
<dt><em>void *</em><code>client_data</code>
<dd>Pointer to client data in the format expected by
the user-defined function.
</dl>
</dir>
<p>
<code>H5Ewalk</code> can fail if there are problems initializing
the library.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5E_direction_t</em> <code>direction</code>
<dd>Direction in which the error stack is to be walked.
<dt><em>H5E_walk_t</em> <code>func</code>
<dd>Function to be called for each error encountered.
<dt><em>void *</em> <code>client_data</code>
<dd>Data to be passed with <code>func</code>.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-WalkCB">H5Ewalk_cb</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Ewalk_cb</code>(<em>int</em> <code>n</code>,
<em>H5E_error_t *</em><code>err_desc</code>,
<em>void</em> <code>*client_data</code>
)
<dt><strong>Purpose:</strong>
<dd>Default error stack traversal callback function
that prints error messages to the specified output stream.
<dt><strong>Description:</strong>
<dd><code>H5Ewalk_cb</code> is a default error stack traversal callback
function that prints error messages to the specified output stream.
It is not meant to be called directly but rather as an
argument to the <code>H5Ewalk()</code> function.
This function is called also by <code>H5Eprint()</code>.
Application writers are encouraged to use this function as a
model for their own error stack walking functions.
<p>
<code>n</code> is a counter for how many times this function
has been called for this particular traversal of the stack.
It always begins at zero for the first error on the stack
(either the top or bottom error, or even both, depending on
the traversal direction and the size of the stack).
<p>
<code>err_desc</code> is an error description. It contains all the
information about a particular error.
<p>
<code>client_data</code> is the same pointer that was passed as the
<code>client_data</code> argument of <code>H5Ewalk()</code>.
It is expected to be a file pointer (or stderr if null).
<dt><strong>Parameters:</strong>
<dl>
<dt><em>int</em> <code>n</code>
<dd>Number of times this function has been called
for this traversal of the stack.
<dt><em>H5E_error_t *</em><code>err_desc</code>
<dd>Error description.
<dt><em>void</em> <code>*client_data</code>
<dd>A file pointer, or stderr if null.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-GetMajor">H5Eget_major</a>
<dt><strong>Signature:</strong>
<dd><em>const char *</em> <code>H5Eget_major</code>(<em>H5E_major_t</em> <code>n</code>)
<dt><strong>Purpose:</strong>
<dd>Returns a character string describing an error specified by a
major error number.
<dt><strong>Description:</strong>
<dd>Given a major error number, <code>H5Eget_major</code> returns a
constant character string that describes the error.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5E_major_t</em> <code>n</code>
<dd>Major error number.
</dl>
<dt><strong>Returns:</strong>
<dd> Returns a character string describing the error if successful.
Otherwise returns "Invalid major error number."
</dl>
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Error-GetMinor">H5Eget_minor</a>
<dt><strong>Signature:</strong>
<dd><em>const char *</em> <code>H5Eget_minor</code>(<em>H5E_minor_t</em> <code>n</code>)
<dt><strong>Purpose:</strong>
<dd>Returns a character string describing an error specified by a
minor error number.
<dt><strong>Description:</strong>
<dd>Given a minor error number, <code>H5Eget_minor</code> returns a
constant character string that describes the error.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5E_minor_t</em> <code>n</code>
<dd>Minor error number.
</dl>
<dt><strong>Returns:</strong>
<dd> Returns a character string describing the error if successful.
Otherwise returns "Invalid minor error number."
</dl>
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="index.html">HDF5 documents and links</a> <br>
<a href="H5.intro.html">Introduction to HDF5</a> <br>
<a href="H5.user.html">HDF5 User's Guide</a> <br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
</td>
<td valign=top align=right>
And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>
<br>
<a href="RM_H5.html">H5</a>
<a href="RM_H5A.html">H5A</a>
<a href="RM_H5D.html">H5D</a>
H5E
<a href="RM_H5F.html">H5F</a>
<a href="RM_H5G.html">H5G</a>
<a href="RM_H5I.html">H5I</a>
<br>
<a href="RM_H5P.html">H5P</a>
<a href="RM_H5R.html">H5R</a>
<a href="RM_H5RA.html">H5RA</a>
<a href="RM_H5S.html">H5S</a>
<a href="RM_H5T.html">H5T</a>
<a href="RM_H5Z.html">H5Z</a>
<a href="Tools.html">Tools</a>
</td></tr>
</table>
</center>
<hr>
<address>
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
<br>
Last modified: 30 October 1998
</body>
</html>
|
