summaryrefslogtreecommitdiffstats
path: root/src/vlib/init.c
blob: 55f260b74ed831297a6009278a7155b4ee92e1ea (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
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * init.c: mechanism for functions to be called at init/exit.
 *
 * Copyright (c) 2008 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <vlib/vlib.h>
#include <vppinfra/ptclosure.h>

/**
 * @file
 * @brief Init function ordering and execution implementation
 * Topological sort for all classes of init functions, and
 * a relatively simple API routine to invoke them.
 */

/*? %%clicmd:group_label Init functions %% ?*/

static int
comma_split (u8 * s, u8 ** a, u8 ** b)
{
  *a = s;

  while (*s && *s != ',')
    s++;

  if (*s == ',')
    *s = 0;
  else
    return 1;

  *b = (u8 *) (s + 1);
  return 0;
}

/**
 * @brief Topological sorter for init function chains.
 * @param head [in/out] address of the listhead to be sorted
 * @returns 0 on success, otherwise a clib_error_t *.
 */

clib_error_t *vlib_sort_init_exit_functions
  (_vlib_init_function_list_elt_t ** head)
{
  uword *index_by_name;
  uword *reg_by_index;
  u8 **init_f_names = 0;
  u8 *init_f_name;
  char **these_constraints;
  char *this_constraint_c;
  u8 **constraints = 0;
  u8 *constraint_tuple;
  u8 *this_constraint;
  char *prev_name;
  u8 **orig, **closure;
  uword *p;
  int i, j, k;
  u8 *a_name, *b_name;
  int a_index, b_index;
  int n_init_fns;
  u32 *result = 0;
  _vlib_init_function_list_elt_t *this_reg = 0;
  hash_pair_t *hp;
  u8 **keys_to_delete = 0;

  /*
   * two hash tables: name to index in init_f_names, and
   * init function registration pointer by index
   */
  index_by_name = hash_create_string (0, sizeof (uword));
  reg_by_index = hash_create (0, sizeof (uword));

  this_reg = *head;

  /* pass 1, collect init fcn names, construct a before b pairs */
  while (this_reg)
    {
      init_f_name = format (0, "%s%c", this_reg->name, 0);
      hash_set (reg_by_index, vec_len (init_f_names), (uword) this_reg);

      hash_set_mem (index_by_name, init_f_name, vec_len (init_f_names));

      vec_add1 (init_f_names, init_f_name);

      these_constraints = this_reg->runs_before;
      while (these_constraints && these_constraints[0])
	{
	  this_constraint_c = these_constraints[0];

	  constraint_tuple = format (0, "%s,%s%c", init_f_name,
				     this_constraint_c, 0);
	  vec_add1 (constraints, constraint_tuple);
	  these_constraints++;
	}

      these_constraints = this_reg->runs_after;
      while (these_constraints && these_constraints[0])
	{
	  this_constraint_c = these_constraints[0];

	  constraint_tuple = format (0, "%s,%s%c",
				     this_constraint_c, init_f_name, 0);
	  vec_add1 (constraints, constraint_tuple);
	  these_constraints++;
	}

      this_reg = this_reg->next_init_function;
    }

  /*
   * pass 2: collect "a then b then c then d" constraints.
   * all init fcns must be known at this point.
   */
  this_reg = *head;
  while (this_reg)
    {
      these_constraints = this_reg->init_order;

      prev_name = 0;
      /* Across the list of constraints */
      while (these_constraints && these_constraints[0])
	{
	  this_constraint_c = these_constraints[0];
	  p = hash_get_mem (index_by_name, this_constraint_c);
	  if (p == 0)
	    {
	      clib_warning
		("order constraint fcn '%s' not found", this_constraint_c);
	      these_constraints++;
	      continue;
	    }

	  if (prev_name == 0)
	    {
	      prev_name = this_constraint_c;
	      these_constraints++;
	      continue;
	    }

	  constraint_tuple = format (0, "%s,%s%c", prev_name,
				     this_constraint_c, 0);
	  vec_add1 (constraints, constraint_tuple);
	  prev_name = this_constraint_c;
	  these_constraints++;
	}
      this_reg = this_reg->next_init_function;
    }

  n_init_fns = vec_len (init_f_names);
  orig = clib_ptclosure_alloc (n_init_fns);

  for (i = 0; i < vec_len (constraints); i++)
    {
      this_constraint = constraints[i];

      if (comma_split (this_constraint, &a_name, &b_name))
	return clib_error_return (0, "comma_split failed!");

      p = hash_get_mem (index_by_name, a_name);
      /*
       * Note: the next two errors mean that something is
       * b0rked. As in: if you code "A runs before on B," and you type
       * B incorrectly, you lose. Nonexistent init functions are tolerated.
       */
      if (p == 0)
	{
	  clib_warning ("init function '%s' not found (before '%s')",
			a_name, b_name);
	  continue;
	}
      a_index = p[0];

      p = hash_get_mem (index_by_name, b_name);
      if (p == 0)
	{
	  clib_warning ("init function '%s' not found (after '%s')",
			b_name, a_name);
	  continue;
	}
      b_index = p[0];

      /* add a before b to the original set of constraints */
      orig[a_index][b_index] = 1;
      vec_free (this_constraint);
    }

  /* Compute the positive transitive closure of the original constraints */
  closure = clib_ptclosure (orig);

  /* Compute a partial order across feature nodes, if one exists. */
again:
  for (i = 0; i < n_init_fns; i++)
    {
      for (j = 0; j < n_init_fns; j++)
	{
	  if (closure[i][j])
	    goto item_constrained;
	}
      /* Item i can be output */
      vec_add1 (result, i);
      {
	for (k = 0; k < n_init_fns; k++)
	  closure[k][i] = 0;
	/*
	 * Add a "Magic" a before a constraint.
	 * This means we'll never output it again
	 */
	closure[i][i] = 1;
	goto again;
      }
    item_constrained:
      ;
    }

  /* see if we got a partial order... */
  if (vec_len (result) != n_init_fns)
    return clib_error_return
      (0, "Failed to find a suitable init function order!");

  /*
   * We win.
   * Bind the index variables, and output the feature node name vector
   * using the partial order we just computed. Result is in stack
   * order, because the entry with the fewest constraints (e.g. none)
   * is output first, etc.
   * Reset the listhead, and add items in result (aka reverse) order.
   */
  *head = 0;
  for (i = 0; i < n_init_fns; i++)
    {
      p = hash_get (reg_by_index, result[i]);
      ASSERT (p != 0);
      this_reg = (_vlib_init_function_list_elt_t *) p[0];

      this_reg->next_init_function = *head;
      *head = this_reg;
    }

  /* Finally, clean up all the fine data we allocated */
  hash_foreach_pair (hp, index_by_name,
  ({
    vec_add1 (keys_to_delete, (u8 *)hp->key);
  }));
  hash_free (index_by_name);
  for (i = 0; i < vec_len (keys_to_delete); i++)
    vec_free (keys_to_delete[i]);
  vec_free (keys_to_delete);
  hash_free (reg_by_index);
  vec_free (result);
  clib_ptclosure_free (orig);
  clib_ptclosure_free (closure);
  return 0;
}

/**
 * @brief call a set of init / exit / main-loop enter functions
 * @param vm vlib_main_t
 * @param head address of the listhead to sort and then invoke
 * @returns 0 on success, clib_error_t * on error
 *
 * The "init_functions_called" hash supports a subtle mix of procedural
 * and formally-specified ordering constraints. The following schemes
 * are *roughly* equivalent:
 *
 * static clib_error_t *init_runs_first (vlib_main_t *vm)
 * {
 *    clib_error_t *error;
 *
 *    ... do some stuff...
 *
 *    if ((error = vlib_call_init_function (init_runs_next)))
 *      return error;
 *    ...
 * }
 * VLIB_INIT_FUNCTION (init_runs_first);
 *
 * and
 *
 * static clib_error_t *init_runs_first (vlib_main_t *vm)
 * {
 *    ... do some stuff...
 * }
 * VLIB_INIT_FUNCTION (init_runs_first) =
 * {
 *     .runs_before = VLIB_INITS("init_runs_next"),
 * };
 *
 * The first form will [most likely] call "init_runs_next" on the
 * spot. The second form means that "init_runs_first" runs before
 * "init_runs_next," possibly much earlier in the sequence.
 *
 * Please DO NOT construct sets of init functions where A before B
 * actually means A *right before* B. It's not necessary - simply combine
 * A and B - and it leads to hugely annoying debugging exercises.
 */

static inline clib_error_t *
call_init_exit_functions_internal (vlib_main_t *vm,
				   _vlib_init_function_list_elt_t **headp,
				   int call_once, int do_sort, int is_global)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  clib_error_t *error = 0;
  _vlib_init_function_list_elt_t *i;

  if (do_sort && (error = vlib_sort_init_exit_functions (headp)))
    return (error);

  i = *headp;
  while (i)
    {
      uword *h;

      if (is_global)
	h = hash_get (vgm->init_functions_called, i->f);
      else
	h = hash_get (vm->worker_init_functions_called, i->f);

      if (call_once && !h)
	{
	  if (call_once)
	    {
	      if (is_global)
		hash_set1 (vgm->init_functions_called, i->f);
	      else
		hash_set1 (vm->worker_init_functions_called, i->f);
	    }
	  error = i->f (vm);
	  if (error)
	    return error;
	}
      i = i->next_init_function;
    }
  return error;
}

clib_error_t *
vlib_call_init_exit_functions (vlib_main_t *vm,
			       _vlib_init_function_list_elt_t **headp,
			       int call_once, int is_global)
{
  return call_init_exit_functions_internal (vm, headp, call_once,
					    1 /* do_sort */, is_global);
}

clib_error_t *
vlib_call_init_exit_functions_no_sort (vlib_main_t *vm,
				       _vlib_init_function_list_elt_t **headp,
				       int call_once, int is_global)
{
  return call_init_exit_functions_internal (vm, headp, call_once,
					    0 /* do_sort */, is_global);
}

clib_error_t *
vlib_call_all_init_functions (vlib_main_t * vm)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  /* Call placeholder functions to make sure purely static modules are
     linked in. */
#define _(f) vlib_##f##_reference ();
  foreach_vlib_module_reference;
#undef _

  return vlib_call_init_exit_functions (vm, &vgm->init_function_registrations,
					1 /* call_once */, 1 /* is_global */);
}

clib_error_t *
vlib_call_all_main_loop_enter_functions (vlib_main_t * vm)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  return vlib_call_init_exit_functions (
    vm, &vgm->main_loop_enter_function_registrations, 1 /* call_once */,
    1 /* is_global */);
}

clib_error_t *
vlib_call_all_main_loop_exit_functions (vlib_main_t * vm)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  return vlib_call_init_exit_functions (
    vm, &vgm->main_loop_exit_function_registrations, 1 /* call_once */,
    1 /* is_global */);
}

clib_error_t *
vlib_call_all_config_functions (vlib_main_t * vm,
				unformat_input_t * input, int is_early)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  clib_error_t *error = 0;
  vlib_config_function_runtime_t *c, **all;
  uword *hash = 0, *p;
  uword i;

  hash = hash_create_string (0, sizeof (uword));
  all = 0;

  c = vgm->config_function_registrations;

  while (c)
    {
      hash_set_mem (hash, c->name, vec_len (all));
      vec_add1 (all, c);
      unformat_init (&c->input, 0, 0);
      c = c->next_registration;
    }

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      u8 *s, *v;

      if (!unformat (input, "%s %v", &s, &v) || !(p = hash_get_mem (hash, s)))
	{
	  error = clib_error_create ("unknown input `%s %v'", s, v);
	  goto done;
	}

      c = all[p[0]];
      if (vec_len (c->input.buffer) > 0)
	vec_add1 (c->input.buffer, ' ');
      vec_add (c->input.buffer, v, vec_len (v));
      vec_free (v);
      vec_free (s);
    }

  for (i = 0; i < vec_len (all); i++)
    {
      c = all[i];

      /* Is this an early config? Are we doing early configs? */
      if (is_early ^ c->is_early)
	continue;

      /* Already called? */
      if (hash_get (vgm->init_functions_called, c->function))
	continue;
      hash_set1 (vgm->init_functions_called, c->function);

      error = c->function (vm, &c->input);
      if (error)
	goto done;
    }

done:
  for (i = 0; i < vec_len (all); i++)
    {
      c = all[i];
      unformat_free (&c->input);
    }
  vec_free (all);
  hash_free (hash);
  return error;
}

void
vlib_init_dump (void)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  int i = 0;

  _vlib_init_function_list_elt_t *head, *this;
  head = vgm->init_function_registrations;

  this = head;
  while (this)
    {
      fformat (stdout, "[%d]: %s\n", i++, this->name);
      this = this->next_init_function;
    }
}

static clib_error_t *
show_init_function_command_fn (vlib_main_t * vm,
			       unformat_input_t * input,
			       vlib_cli_command_t * cmd)
{
  vlib_global_main_t *vgm = vlib_get_global_main ();
  int which = 1;
  int verbose = 0;
  int i, n_init_fns;
  _vlib_init_function_list_elt_t *head, *this;
  uword *index_by_name;
  uword *reg_by_index;
  u8 **init_f_names = 0;
  u8 *init_f_name;
  uword *p;
  _vlib_init_function_list_elt_t *this_reg = 0;
  hash_pair_t *hp;
  u8 **keys_to_delete = 0;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "init"))
	which = 1;
      else if (unformat (input, "enter"))
	which = 2;
      else if (unformat (input, "exit"))
	which = 3;
      else if (unformat (input, "verbose %d", &verbose))
	;
      else if (unformat (input, "verbose"))
	verbose = 1;
      else
	break;
    }

  switch (which)
    {
    case 1:
      head = vgm->init_function_registrations;
      break;
    case 2:
      head = vgm->main_loop_enter_function_registrations;
      break;
    case 3:
      head = vgm->main_loop_exit_function_registrations;
      break;
    default:
      return clib_error_return (0, "BUG");
    }

  if (verbose == 0)
    {
      this = head;
      i = 0;
      while (this)
	{
	  vlib_cli_output (vm, "[%d]: %s", i++, this->name);
	  this = this->next_init_function;
	}
      return 0;
    }

  index_by_name = hash_create_string (0, sizeof (uword));
  reg_by_index = hash_create (0, sizeof (uword));

  this_reg = head;
  n_init_fns = 0;
  /* collect init fcn names */
  while (this_reg)
    {
      init_f_name = format (0, "%s%c", this_reg->name, 0);
      hash_set (reg_by_index, vec_len (init_f_names), (uword) this_reg);

      hash_set_mem (index_by_name, init_f_name, vec_len (init_f_names));
      vec_add1 (init_f_names, init_f_name);
      n_init_fns++;
      this_reg = this_reg->next_init_function;
    }

  for (i = 0; i < n_init_fns; i++)
    {
      p = hash_get (reg_by_index, i);
      ASSERT (p != 0);
      this_reg = (_vlib_init_function_list_elt_t *) p[0];
      vlib_cli_output (vm, "[%d] %s", i, this_reg->name);
      {
	char **runs_before, **runs_after, **init_order;
	runs_before = this_reg->runs_before;
	while (runs_before && runs_before[0])
	  {
	    _vlib_init_function_list_elt_t *successor;
	    uword successor_index;
	    p = hash_get_mem (index_by_name, runs_before[0]);
	    if (p == 0)
	      {
		clib_warning ("couldn't find successor '%s'", runs_before[0]);
		runs_before++;
		continue;
	      }
	    successor_index = p[0];
	    p = hash_get (reg_by_index, p[0]);
	    ASSERT (p != 0);
	    successor = (_vlib_init_function_list_elt_t *) p[0];
	    vlib_cli_output (vm, "  before '%s' [%lld]",
			     successor->name, successor_index);
	    runs_before++;
	  }
	runs_after = this_reg->runs_after;
	while (runs_after && runs_after[0])
	  {
	    _vlib_init_function_list_elt_t *predecessor;
	    uword predecessor_index;
	    p = hash_get_mem (index_by_name, runs_after[0]);
	    if (p == 0)
	      {
		clib_warning ("couldn't find predecessor '%s'",
			      runs_after[0]);
		runs_after++;
		continue;
	      }
	    predecessor_index = p[0];
	    p = hash_get (reg_by_index, p[0]);
	    ASSERT (p != 0);
	    predecessor = (_vlib_init_function_list_elt_t *) p[0];
	    vlib_cli_output (vm, "  after '%s' [%lld]",
			     predecessor->name, predecessor_index);
	    runs_after++;
	  }
	init_order = this_reg->init_order;
	while (init_order && init_order[0])
	  {
	    _vlib_init_function_list_elt_t *inorder;
	    uword inorder_index;
	    p = hash_get_mem (index_by_name, init_order[0]);
	    if (p == 0)
	      {
		clib_warning ("couldn't find order element'%s'",
			      init_order[0]);
		init_order++;
		continue;
	      }
	    inorder_index = p[0];
	    p = hash_get (reg_by_index, p[0]);
	    ASSERT (p != 0);
	    inorder = (_vlib_init_function_list_elt_t *) p[0];
	    vlib_cli_output (vm, "  in order '%s' [%lld]",
			     inorder->name, inorder_index);
	    init_order++;
	  }
      }
    }
  hash_foreach_pair (hp, index_by_name,
  ({
    vec_add1 (keys_to_delete, (u8 *)hp->key);
  }));
  hash_free (index_by_name);
  for (i = 0; i < vec_len (keys_to_delete); i++)
    vec_free (keys_to_delete[i]);
  vec_free (keys_to_delete);
  hash_free (reg_by_index);

  return 0;
}

/*?
 * Show init function order
 *
 * @cliexpar
 * @cliexstart{show init-function [init | enter | exit] [verbose [nn]]}
 * @cliexend
 ?*/
VLIB_CLI_COMMAND (show_init_function, static) = {
  .path = "show init-function",
  .short_help = "show init-function [init | enter | exit][verbose [nn]]",
  .function = show_init_function_command_fn,
};


/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */