aboutsummaryrefslogtreecommitdiffstats
path: root/src/vlibmemory/memory_api.c
blob: f334714e18e7222fcb08fe28f658d0accdddf09b (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
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
/*
 *------------------------------------------------------------------
 * Copyright (c) 2018 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.
 *------------------------------------------------------------------
 */
#include <signal.h>

#include <vlib/vlib.h>
#include <vlibapi/api.h>
#include <vlibmemory/api.h>
#include <vlibmemory/memory_api.h>

#include <vlibmemory/vl_memory_msg_enum.h>	/* enumerate all vlib messages */

#define vl_typedefs		/* define message structures */
#include <vlibmemory/vl_memory_api_h.h>
#undef vl_typedefs

/* instantiate all the print functions we know about */
#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
#define vl_printfun
#include <vlibmemory/vl_memory_api_h.h>
#undef vl_printfun

/* instantiate all the endian swap functions we know about */
#define vl_endianfun
#include <vlibmemory/vl_memory_api_h.h>
#undef vl_endianfun

static inline void *
vl_api_memclnt_create_t_print (vl_api_memclnt_create_t * a, void *handle)
{
  vl_print (handle, "vl_api_memclnt_create_t:\n");
  vl_print (handle, "name: %s\n", a->name);
  vl_print (handle, "input_queue: 0x%wx\n", a->input_queue);
  vl_print (handle, "context: %u\n", (unsigned) a->context);
  vl_print (handle, "ctx_quota: %ld\n", (long) a->ctx_quota);
  return handle;
}

static inline void *
vl_api_memclnt_delete_t_print (vl_api_memclnt_delete_t * a, void *handle)
{
  vl_print (handle, "vl_api_memclnt_delete_t:\n");
  vl_print (handle, "index: %u\n", (unsigned) a->index);
  vl_print (handle, "handle: 0x%wx\n", a->handle);
  return handle;
}

volatile int **vl_api_queue_cursizes;

static void
memclnt_queue_callback (vlib_main_t * vm)
{
  int i;
  api_main_t *am = &api_main;

  if (PREDICT_FALSE (vec_len (vl_api_queue_cursizes) !=
		     1 + vec_len (am->vlib_private_rps)))
    {
      vl_shmem_hdr_t *shmem_hdr = am->shmem_hdr;
      svm_queue_t *q;

      if (shmem_hdr == 0)
	return;

      q = shmem_hdr->vl_input_queue;
      if (q == 0)
	return;

      vec_add1 (vl_api_queue_cursizes, &q->cursize);

      for (i = 0; i < vec_len (am->vlib_private_rps); i++)
	{
	  svm_region_t *vlib_rp = am->vlib_private_rps[i];

	  shmem_hdr = (void *) vlib_rp->user_ctx;
	  q = shmem_hdr->vl_input_queue;
	  vec_add1 (vl_api_queue_cursizes, &q->cursize);
	}
    }

  for (i = 0; i < vec_len (vl_api_queue_cursizes); i++)
    {
      if (*vl_api_queue_cursizes[i])
	{
	  vm->queue_signal_pending = 1;
	  vm->api_queue_nonempty = 1;
	  vlib_process_signal_event (vm, vl_api_clnt_node.index,
				     /* event_type */ QUEUE_SIGNAL_EVENT,
				     /* event_data */ 0);
	  break;
	}
    }
  if (vec_len (vm->pending_rpc_requests))
    {
      vm->queue_signal_pending = 1;
      vm->api_queue_nonempty = 1;
      vlib_process_signal_event (vm, vl_api_clnt_node.index,
				 /* event_type */ QUEUE_SIGNAL_EVENT,
				 /* event_data */ 0);
    }
}

/*
 * vl_api_memclnt_create_internal
 */
u32
vl_api_memclnt_create_internal (char *name, svm_queue_t * q)
{
  vl_api_registration_t **regpp;
  vl_api_registration_t *regp;
  svm_region_t *svm;
  void *oldheap;
  api_main_t *am = &api_main;

  ASSERT (vlib_get_thread_index () == 0);
  pool_get (am->vl_clients, regpp);

  svm = am->vlib_rp;

  pthread_mutex_lock (&svm->mutex);
  oldheap = svm_push_data_heap (svm);
  *regpp = clib_mem_alloc (sizeof (vl_api_registration_t));

  regp = *regpp;
  clib_memset (regp, 0, sizeof (*regp));
  regp->registration_type = REGISTRATION_TYPE_SHMEM;
  regp->vl_api_registration_pool_index = regpp - am->vl_clients;
  regp->vlib_rp = svm;
  regp->shmem_hdr = am->shmem_hdr;

  regp->vl_input_queue = q;
  regp->name = format (0, "%s%c", name, 0);

  pthread_mutex_unlock (&svm->mutex);
  svm_pop_heap (oldheap);
  return vl_msg_api_handle_from_index_and_epoch
    (regp->vl_api_registration_pool_index,
     am->shmem_hdr->application_restarts);
}

/*
 * vl_api_memclnt_create_t_handler
 */
void
vl_api_memclnt_create_t_handler (vl_api_memclnt_create_t * mp)
{
  vl_api_registration_t **regpp;
  vl_api_registration_t *regp;
  vl_api_memclnt_create_reply_t *rp;
  svm_region_t *svm;
  svm_queue_t *q;
  int rv = 0;
  void *oldheap;
  api_main_t *am = &api_main;
  u8 *msg_table;

  /*
   * This is tortured. Maintain a vlib-address-space private
   * pool of client registrations. We use the shared-memory virtual
   * address of client structure as a handle, to allow direct
   * manipulation of context quota vbls from the client library.
   *
   * This scheme causes trouble w/ API message trace replay, since
   * some random VA from clib_mem_alloc() certainly won't
   * occur in the Linux sim. The (very) few places
   * that care need to use the pool index.
   *
   * Putting the registration object(s) into a pool in shared memory and
   * using the pool index as a handle seems like a great idea.
   * Unfortunately, each and every reference to that pool would need
   * to be protected by a mutex:
   *
   *     Client                      VLIB
   *     ------                      ----
   *     convert pool index to
   *     pointer.
   *     <deschedule>
   *                                 expand pool
   *                                 <deschedule>
   *     kaboom!
   */

  pool_get (am->vl_clients, regpp);

  svm = am->vlib_rp;

  pthread_mutex_lock (&svm->mutex);
  oldheap = svm_push_data_heap (svm);
  *regpp = clib_mem_alloc (sizeof (vl_api_registration_t));

  regp = *regpp;
  clib_memset (regp, 0, sizeof (*regp));
  regp->registration_type = REGISTRATION_TYPE_SHMEM;
  regp->vl_api_registration_pool_index = regpp - am->vl_clients;
  regp->vlib_rp = svm;
  regp->shmem_hdr = am->shmem_hdr;
  regp->clib_file_index = am->shmem_hdr->clib_file_index;

  q = regp->vl_input_queue = (svm_queue_t *) (uword) mp->input_queue;

  regp->name = format (0, "%s", mp->name);
  vec_add1 (regp->name, 0);

  if (am->serialized_message_table_in_shmem == 0)
    am->serialized_message_table_in_shmem =
      vl_api_serialize_message_table (am, 0);

  if (am->vlib_rp != am->vlib_primary_rp)
    msg_table = vl_api_serialize_message_table (am, 0);
  else
    msg_table = am->serialized_message_table_in_shmem;

  pthread_mutex_unlock (&svm->mutex);
  svm_pop_heap (oldheap);

  rp = vl_msg_api_alloc (sizeof (*rp));
  rp->_vl_msg_id = ntohs (VL_API_MEMCLNT_CREATE_REPLY);
  rp->handle = (uword) regp;
  rp->index = vl_msg_api_handle_from_index_and_epoch
    (regp->vl_api_registration_pool_index,
     am->shmem_hdr->application_restarts);
  rp->context = mp->context;
  rp->response = ntohl (rv);
  rp->message_table = pointer_to_uword (msg_table);

  vl_msg_api_send_shmem (q, (u8 *) & rp);
}

int
vl_api_call_reaper_functions (u32 client_index)
{
  clib_error_t *error = 0;
  _vl_msg_api_function_list_elt_t *i;

  i = api_main.reaper_function_registrations;
  while (i)
    {
      error = i->f (client_index);
      if (error)
	clib_error_report (error);
      i = i->next_init_function;
    }
  return 0;
}

/*
 * vl_api_memclnt_delete_t_handler
 */
void
vl_api_memclnt_delete_t_handler (vl_api_memclnt_delete_t * mp)
{
  vl_api_registration_t **regpp;
  vl_api_registration_t *regp;
  vl_api_memclnt_delete_reply_t *rp;
  svm_region_t *svm;
  void *oldheap;
  api_main_t *am = &api_main;
  u32 handle, client_index, epoch;

  handle = mp->index;

  if (vl_api_call_reaper_functions (handle))
    return;

  epoch = vl_msg_api_handle_get_epoch (handle);
  client_index = vl_msg_api_handle_get_index (handle);

  if (epoch != (am->shmem_hdr->application_restarts & VL_API_EPOCH_MASK))
    {
      clib_warning
	("Stale clnt delete index %d old epoch %d cur epoch %d",
	 client_index, epoch,
	 (am->shmem_hdr->application_restarts & VL_API_EPOCH_MASK));
      return;
    }

  regpp = pool_elt_at_index (am->vl_clients, client_index);

  if (!pool_is_free (am->vl_clients, regpp))
    {
      int i;
      regp = *regpp;
      svm = am->vlib_rp;
      int private_registration = 0;

      /* Send reply unless client asked us to do the cleanup */
      if (!mp->do_cleanup)
	{
	  /*
	   * Note: the API message handling path will set am->vlib_rp
	   * as appropriate for pairwise / private memory segments
	   */
	  rp = vl_msg_api_alloc (sizeof (*rp));
	  rp->_vl_msg_id = ntohs (VL_API_MEMCLNT_DELETE_REPLY);
	  rp->handle = mp->handle;
	  rp->response = 1;

	  vl_msg_api_send_shmem (regp->vl_input_queue, (u8 *) & rp);
	  if (client_index != regp->vl_api_registration_pool_index)
	    {
	      clib_warning ("mismatch client_index %d pool_index %d",
			    client_index,
			    regp->vl_api_registration_pool_index);
	      vl_msg_api_free (rp);
	      return;
	    }
	}

      /* For horizontal scaling, add a hash table... */
      for (i = 0; i < vec_len (am->vlib_private_rps); i++)
	{
	  /* Is this a pairwise / private API segment? */
	  if (am->vlib_private_rps[i] == svm)
	    {
	      /* Note: account for the memfd header page */
	      uword virtual_base = svm->virtual_base - MMAP_PAGESIZE;
	      uword virtual_size = svm->virtual_size + MMAP_PAGESIZE;

	      /*
	       * Kill the registration pool element before we make
	       * the index vanish forever
	       */
	      pool_put_index (am->vl_clients,
			      regp->vl_api_registration_pool_index);

	      vec_delete (am->vlib_private_rps, 1, i);
	      /* Kill it, accounting for the memfd header page */
	      if (munmap ((void *) virtual_base, virtual_size) < 0)
		clib_unix_warning ("munmap");
	      /* Reset the queue-length-address cache */
	      vec_reset_length (vl_api_queue_cursizes);
	      private_registration = 1;
	      break;
	    }
	}

      /* No dangling references, please */
      *regpp = 0;

      if (private_registration == 0)
	{
	  pool_put_index (am->vl_clients,
			  regp->vl_api_registration_pool_index);
	  pthread_mutex_lock (&svm->mutex);
	  oldheap = svm_push_data_heap (svm);
	  if (mp->do_cleanup)
	    svm_queue_free (regp->vl_input_queue);
	  vec_free (regp->name);
	  /* Poison the old registration */
	  clib_memset (regp, 0xF1, sizeof (*regp));
	  clib_mem_free (regp);
	  pthread_mutex_unlock (&svm->mutex);
	  svm_pop_heap (oldheap);
	  /*
	   * These messages must be freed manually, since they're set up
	   * as "bounce" messages. In the private_registration == 1 case,
	   * we kill the shared-memory segment which contains the message
	   * with munmap.
	   */
	  vl_msg_api_free (mp);
	}
    }
  else
    {
      clib_warning ("unknown client ID %d", mp->index);
    }
}

/**
 * client answered a ping, stave off the grim reaper...
 */
void
  vl_api_memclnt_keepalive_reply_t_handler
  (vl_api_memclnt_keepalive_reply_t * mp)
{
  vl_api_registration_t *regp;
  vlib_main_t *vm = vlib_get_main ();

  regp = vl_api_client_index_to_registration (mp->context);
  if (regp)
    {
      regp->last_heard = vlib_time_now (vm);
      regp->unanswered_pings = 0;
    }
  else
    clib_warning ("BUG: anonymous memclnt_keepalive_reply");
}

/**
 * We can send ourselves these messages if someone uses the
 * builtin binary api test tool...
 */
static void
vl_api_memclnt_keepalive_t_handler (vl_api_memclnt_keepalive_t * mp)
{
  vl_api_memclnt_keepalive_reply_t *rmp;
  api_main_t *am;
  vl_shmem_hdr_t *shmem_hdr;

  am = &api_main;
  shmem_hdr = am->shmem_hdr;

  rmp = vl_msg_api_alloc_as_if_client (sizeof (*rmp));
  clib_memset (rmp, 0, sizeof (*rmp));
  rmp->_vl_msg_id = ntohs (VL_API_MEMCLNT_KEEPALIVE_REPLY);
  rmp->context = mp->context;
  vl_msg_api_send_shmem (shmem_hdr->vl_input_queue, (u8 *) & rmp);
}

/*
 * To avoid filling the API trace buffer with boring messages,
 * don't trace memclnt_keepalive[_reply] msgs
 */

#define foreach_vlib_api_msg                            \
_(MEMCLNT_CREATE, memclnt_create, 1)                    \
_(MEMCLNT_DELETE, memclnt_delete, 1)                    \
_(MEMCLNT_KEEPALIVE, memclnt_keepalive, 0)              \
_(MEMCLNT_KEEPALIVE_REPLY, memclnt_keepalive_reply, 0)

/*
 * memory_api_init
 */
int
vl_mem_api_init (const char *region_name)
{
  int rv;
  api_main_t *am = &api_main;
  vl_msg_api_msg_config_t cfg;
  vl_msg_api_msg_config_t *c = &cfg;
  vl_shmem_hdr_t *shm;
  vlib_main_t *vm = vlib_get_main ();

  clib_memset (c, 0, sizeof (*c));

  if ((rv = vl_map_shmem (region_name, 1 /* is_vlib */ )) < 0)
    return rv;

#define _(N,n,t) do {                                            \
    c->id = VL_API_##N;                                         \
    c->name = #n;                                               \
    c->handler = vl_api_##n##_t_handler;                        \
    c->cleanup = vl_noop_handler;                               \
    c->endian = vl_api_##n##_t_endian;                          \
    c->print = vl_api_##n##_t_print;                            \
    c->size = sizeof(vl_api_##n##_t);                           \
    c->traced = t; /* trace, so these msgs print */             \
    c->replay = 0; /* don't replay client create/delete msgs */ \
    c->message_bounce = 0; /* don't bounce this message */	\
    vl_msg_api_config(c);} while (0);

  foreach_vlib_api_msg;
#undef _

  /*
   * special-case freeing of memclnt_delete messages, so we can
   * simply munmap pairwise / private API segments...
   */
  am->message_bounce[VL_API_MEMCLNT_DELETE] = 1;
  am->is_mp_safe[VL_API_MEMCLNT_KEEPALIVE_REPLY] = 1;

  vlib_set_queue_signal_callback (vm, memclnt_queue_callback);

  shm = am->shmem_hdr;
  ASSERT (shm && shm->vl_input_queue);

  /* Make a note so we can always find the primary region easily */
  am->vlib_primary_rp = am->vlib_rp;

  return 0;
}

clib_error_t *
map_api_segment_init (vlib_main_t * vm)
{
  api_main_t *am = &api_main;
  int rv;

  if ((rv = vl_mem_api_init (am->region_name)) < 0)
    {
      return clib_error_return (0, "vl_mem_api_init (%s) failed",
				am->region_name);
    }
  return 0;
}

static void
send_memclnt_keepalive (vl_api_registration_t * regp, f64 now)
{
  vl_api_memclnt_keepalive_t *mp;
  svm_queue_t *q;
  api_main_t *am = &api_main;
  svm_region_t *save_vlib_rp = am->vlib_rp;
  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;

  q = regp->vl_input_queue;

  /*
   * If the queue head is moving, assume that the client is processing
   * messages and skip the ping. This heuristic may fail if the queue
   * is in the same position as last time, net of wrapping; in which
   * case, the client will receive a keepalive.
   */
  if (regp->last_queue_head != q->head)
    {
      regp->last_heard = now;
      regp->unanswered_pings = 0;
      regp->last_queue_head = q->head;
      return;
    }

  /*
   * push/pop shared memory segment, so this routine
   * will work with "normal" as well as "private segment"
   * memory clients..
   */

  am->vlib_rp = regp->vlib_rp;
  am->shmem_hdr = regp->shmem_hdr;

  mp = vl_msg_api_alloc (sizeof (*mp));
  clib_memset (mp, 0, sizeof (*mp));
  mp->_vl_msg_id = clib_host_to_net_u16 (VL_API_MEMCLNT_KEEPALIVE);
  mp->context = mp->client_index =
    vl_msg_api_handle_from_index_and_epoch
    (regp->vl_api_registration_pool_index,
     am->shmem_hdr->application_restarts);

  regp->unanswered_pings++;

  /* Failure-to-send due to a stuffed queue is absolutely expected */
  if (svm_queue_add (q, (u8 *) & mp, 1 /* nowait */ ))
    vl_msg_api_free (mp);

  am->vlib_rp = save_vlib_rp;
  am->shmem_hdr = save_shmem_hdr;
}

static void
vl_mem_send_client_keepalive_w_reg (api_main_t * am, f64 now,
				    vl_api_registration_t ** regpp,
				    u32 ** dead_indices,
				    u32 ** confused_indices)
{
  vl_api_registration_t *regp = *regpp;
  if (regp)
    {
      /* If we haven't heard from this client recently... */
      if (regp->last_heard < (now - 10.0))
	{
	  if (regp->unanswered_pings == 2)
	    {
	      svm_queue_t *q;
	      q = regp->vl_input_queue;
	      if (kill (q->consumer_pid, 0) >= 0)
		{
		  clib_warning ("REAPER: lazy binary API client '%s'",
				regp->name);
		  regp->unanswered_pings = 0;
		  regp->last_heard = now;
		}
	      else
		{
		  clib_warning ("REAPER: binary API client '%s' died",
				regp->name);
		  vec_add1 (*dead_indices, regpp - am->vl_clients);
		}
	    }
	  else
	    send_memclnt_keepalive (regp, now);
	}
      else
	regp->unanswered_pings = 0;
    }
  else
    {
      clib_warning ("NULL client registration index %d",
		    regpp - am->vl_clients);
      vec_add1 (*confused_indices, regpp - am->vl_clients);
    }
}

void
vl_mem_api_dead_client_scan (api_main_t * am, vl_shmem_hdr_t * shm, f64 now)
{
  vl_api_registration_t **regpp;
  static u32 *dead_indices;
  static u32 *confused_indices;

  vec_reset_length (dead_indices);
  vec_reset_length (confused_indices);

  /* *INDENT-OFF* */
  pool_foreach (regpp, am->vl_clients, ({
      vl_mem_send_client_keepalive_w_reg (am, now, regpp, &dead_indices,
                                          &confused_indices);
  }));
  /* *INDENT-ON* */

  /* This should "never happen," but if it does, fix it... */
  if (PREDICT_FALSE (vec_len (confused_indices) > 0))
    {
      int i;
      for (i = 0; i < vec_len (confused_indices); i++)
	{
	  pool_put_index (am->vl_clients, confused_indices[i]);
	}
    }

  if (PREDICT_FALSE (vec_len (dead_indices) > 0))
    {
      int i;
      svm_region_t *svm;
      void *oldheap;

      /* Allow the application to clean up its registrations */
      for (i = 0; i < vec_len (dead_indices); i++)
	{
	  regpp = pool_elt_at_index (am->vl_clients, dead_indices[i]);
	  if (regpp)
	    {
	      u32 handle;

	      handle = vl_msg_api_handle_from_index_and_epoch
		(dead_indices[i], shm->application_restarts);
	      (void) vl_api_call_reaper_functions (handle);
	    }
	}

      svm = am->vlib_rp;
      pthread_mutex_lock (&svm->mutex);
      oldheap = svm_push_data_heap (svm);

      for (i = 0; i < vec_len (dead_indices); i++)
	{
	  regpp = pool_elt_at_index (am->vl_clients, dead_indices[i]);
	  if (regpp)
	    {
	      /* Is this a pairwise SVM segment? */
	      if ((*regpp)->vlib_rp != svm)
		{
		  int i;
		  svm_region_t *dead_rp = (*regpp)->vlib_rp;
		  /* Note: account for the memfd header page */
		  uword virtual_base = dead_rp->virtual_base - MMAP_PAGESIZE;
		  uword virtual_size = dead_rp->virtual_size + MMAP_PAGESIZE;

		  /* For horizontal scaling, add a hash table... */
		  for (i = 0; i < vec_len (am->vlib_private_rps); i++)
		    if (am->vlib_private_rps[i] == dead_rp)
		      {
			vec_delete (am->vlib_private_rps, 1, i);
			goto found;
		      }
		  clib_warning ("private rp %llx AWOL", dead_rp);

		found:
		  /* Kill it, accounting for the memfd header page */
		  if (munmap ((void *) virtual_base, virtual_size) < 0)
		    clib_unix_warning ("munmap");
		  /* Reset the queue-length-address cache */
		  vec_reset_length (vl_api_queue_cursizes);
		}
	      else
		{
		  /* Poison the old registration */
		  clib_memset (*regpp, 0xF3, sizeof (**regpp));
		  clib_mem_free (*regpp);
		}
	      /* no dangling references, please */
	      *regpp = 0;
	    }
	  else
	    {
	      svm_pop_heap (oldheap);
	      clib_warning ("Duplicate free, client index %d",
			    regpp - am->vl_clients);
	      oldheap = svm_push_data_heap (svm);
	    }
	}

      svm_client_scan_this_region_nolock (am->vlib_rp);

      pthread_mutex_unlock (&svm->mutex);
      svm_pop_heap (oldheap);
      for (i = 0; i < vec_len (dead_indices); i++)
	pool_put_index (am->vl_clients, dead_indices[i]);
    }
}

static inline int
void_mem_api_handle_msg_i (api_main_t * am, vlib_main_t * vm,
			   vlib_node_runtime_t * node, svm_queue_t * q)
{
  uword mp;
  if (!svm_queue_sub2 (q, (u8 *) & mp))
    {
      vl_msg_api_handler_with_vm_node (am, (void *) mp, vm, node);
      return 0;
    }
  return -1;
}

int
vl_mem_api_handle_msg_main (vlib_main_t * vm, vlib_node_runtime_t * node)
{
  api_main_t *am = &api_main;
  return void_mem_api_handle_msg_i (am, vm, node,
				    am->shmem_hdr->vl_input_queue);
}

int
vl_mem_api_handle_rpc (vlib_main_t * vm, vlib_node_runtime_t * node)
{
  api_main_t *am = &api_main;
  int i;
  uword *tmp, mp;

  /*
   * Swap pending and processing vectors, then process the RPCs
   * Avoid deadlock conditions by construction.
   */
  clib_spinlock_lock_if_init (&vm->pending_rpc_lock);
  tmp = vm->processing_rpc_requests;
  vec_reset_length (tmp);
  vm->processing_rpc_requests = vm->pending_rpc_requests;
  vm->pending_rpc_requests = tmp;
  clib_spinlock_unlock_if_init (&vm->pending_rpc_lock);

  /*
   * RPCs are used to reflect function calls to thread 0
   * when the underlying code is not thread-safe.
   *
   * Grabbing the thread barrier across a set of RPCs
   * greatly increases efficiency, and avoids
   * running afoul of the barrier sync holddown timer.
   * The barrier sync code supports recursive locking.
   *
   * We really need to rewrite RPC-based code...
   */
  if (PREDICT_TRUE (vec_len (vm->processing_rpc_requests)))
    {
      vl_msg_api_barrier_sync ();
      for (i = 0; i < vec_len (vm->processing_rpc_requests); i++)
	{
	  mp = vm->processing_rpc_requests[i];
	  vl_msg_api_handler_with_vm_node (am, (void *) mp, vm, node);
	}
      vl_msg_api_barrier_release ();
    }

  return 0;
}

int
vl_mem_api_handle_msg_private (vlib_main_t * vm, vlib_node_runtime_t * node,
			       u32 reg_index)
{
  api_main_t *am = &api_main;
  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
  svm_region_t *vlib_rp, *save_vlib_rp = am->vlib_rp;
  svm_queue_t *q;
  int rv;

  vlib_rp = am->vlib_rp = am->vlib_private_rps[reg_index];

  am->shmem_hdr = (void *) vlib_rp->user_ctx;
  q = am->shmem_hdr->vl_input_queue;

  rv = void_mem_api_handle_msg_i (am, vm, node, q);

  am->shmem_hdr = save_shmem_hdr;
  am->vlib_rp = save_vlib_rp;

  return rv;
}

vl_api_registration_t *
vl_mem_api_client_index_to_registration (u32 handle)
{
  vl_api_registration_t **regpp;
  vl_api_registration_t *regp;
  api_main_t *am = &api_main;
  vl_shmem_hdr_t *shmem_hdr;
  u32 index;

  index = vl_msg_api_handle_get_index (handle);
  regpp = am->vl_clients + index;

  if (pool_is_free (am->vl_clients, regpp))
    {
      vl_msg_api_increment_missing_client_counter ();
      return 0;
    }
  regp = *regpp;

  shmem_hdr = (vl_shmem_hdr_t *) regp->shmem_hdr;
  if (!vl_msg_api_handle_is_valid (handle, shmem_hdr->application_restarts))
    {
      vl_msg_api_increment_missing_client_counter ();
      return 0;
    }

  return (regp);
}

svm_queue_t *
vl_api_client_index_to_input_queue (u32 index)
{
  vl_api_registration_t *regp;
  api_main_t *am = &api_main;

  /* Special case: vlib trying to send itself a message */
  if (index == (u32) ~ 0)
    return (am->shmem_hdr->vl_input_queue);

  regp = vl_mem_api_client_index_to_registration (index);
  if (!regp)
    return 0;
  return (regp->vl_input_queue);
}

static clib_error_t *
setup_memclnt_exit (vlib_main_t * vm)
{
  atexit (vl_unmap_shmem);
  return 0;
}

VLIB_INIT_FUNCTION (setup_memclnt_exit);

u8 *
format_api_message_rings (u8 * s, va_list * args)
{
  api_main_t *am = va_arg (*args, api_main_t *);
  vl_shmem_hdr_t *shmem_hdr = va_arg (*args, vl_shmem_hdr_t *);
  int main_segment = va_arg (*args, int);
  ring_alloc_t *ap;
  int i;

  if (shmem_hdr == 0)
    return format (s, "%8s %8s %8s %8s %8s\n",
		   "Owner", "Size", "Nitems", "Hits", "Misses");

  ap = shmem_hdr->vl_rings;

  for (i = 0; i < vec_len (shmem_hdr->vl_rings); i++)
    {
      s = format (s, "%8s %8d %8d %8d %8d\n",
		  "vlib", ap->size, ap->nitems, ap->hits, ap->misses);
      ap++;
    }

  ap = shmem_hdr->client_rings;

  for (i = 0; i < vec_len (shmem_hdr->client_rings); i++)
    {
      s = format (s, "%8s %8d %8d %8d %8d\n",
		  "clnt", ap->size, ap->nitems, ap->hits, ap->misses);
      ap++;
    }

  if (main_segment)
    {
      s = format (s, "%d ring miss fallback allocations\n", am->ring_misses);
      s = format
	(s,
	 "%d application restarts, %d reclaimed msgs, %d garbage collects\n",
	 shmem_hdr->application_restarts, shmem_hdr->restart_reclaims,
	 shmem_hdr->garbage_collects);
    }
  return s;
}

static clib_error_t *
vl_api_ring_command (vlib_main_t * vm,
		     unformat_input_t * input, vlib_cli_command_t * cli_cmd)
{
  int i;
  vl_shmem_hdr_t *shmem_hdr;
  api_main_t *am = &api_main;

  /* First, dump the primary region rings.. */

  if (am->vlib_primary_rp == 0 || am->vlib_primary_rp->user_ctx == 0)
    {
      vlib_cli_output (vm, "Shared memory segment not initialized...\n");
      return 0;
    }

  shmem_hdr = (void *) am->vlib_primary_rp->user_ctx;

  vlib_cli_output (vm, "Main API segment rings:");

  vlib_cli_output (vm, "%U", format_api_message_rings, am,
		   0 /* print header */ , 0 /* notused */ );

  vlib_cli_output (vm, "%U", format_api_message_rings, am,
		   shmem_hdr, 1 /* main segment */ );

  for (i = 0; i < vec_len (am->vlib_private_rps); i++)
    {
      svm_region_t *vlib_rp = am->vlib_private_rps[i];
      shmem_hdr = (void *) vlib_rp->user_ctx;
      vl_api_registration_t **regpp;
      vl_api_registration_t *regp = 0;

      /* For horizontal scaling, add a hash table... */
      /* *INDENT-OFF* */
      pool_foreach (regpp, am->vl_clients,
      ({
        regp = *regpp;
        if (regp && regp->vlib_rp == vlib_rp)
          {
            vlib_cli_output (vm, "%s segment rings:", regp->name);
            goto found;
          }
      }));
      vlib_cli_output (vm, "regp %llx not found?", regp);
      continue;
      /* *INDENT-ON* */
    found:
      vlib_cli_output (vm, "%U", format_api_message_rings, am,
		       0 /* print header */ , 0 /* notused */ );
      vlib_cli_output (vm, "%U", format_api_message_rings, am,
		       shmem_hdr, 0 /* main segment */ );
    }

  return 0;
}

/*?
 * Display binary api message allocation ring statistics
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (cli_show_api_ring_command, static) =
{
  .path = "show api ring-stats",
  .short_help = "Message ring statistics",
  .function = vl_api_ring_command,
};
/* *INDENT-ON* */

clib_error_t *
vlibmemory_init (vlib_main_t * vm)
{
  api_main_t *am = &api_main;
  svm_map_region_args_t _a, *a = &_a;
  clib_error_t *error;
  u8 *remove_path1, *remove_path2;

  /*
   * By popular request / to avoid support fires, remove any old api segment
   * files Right Here.
   */
  if (am->root_path == 0)
    {
      remove_path1 = format (0, "/dev/shm/global_vm%c", 0);
      remove_path2 = format (0, "/dev/shm/vpe-api%c", 0);
    }
  else
    {
      remove_path1 = format (0, "/dev/shm/%s-global_vm%c", am->root_path, 0);
      remove_path2 = format (0, "/dev/shm/%s-vpe-api%c", am->root_path, 0);
    }

  (void) unlink ((char *) remove_path1);
  (void) unlink ((char *) remove_path2);

  vec_free (remove_path1);
  vec_free (remove_path2);

  clib_memset (a, 0, sizeof (*a));
  a->root_path = am->root_path;
  a->name = SVM_GLOBAL_REGION_NAME;
  a->baseva = (am->global_baseva != 0) ?
    am->global_baseva : +svm_get_global_region_base_va ();
  a->size = (am->global_size != 0) ? am->global_size : SVM_GLOBAL_REGION_SIZE;
  a->flags = SVM_FLAGS_NODATA;
  a->uid = am->api_uid;
  a->gid = am->api_gid;
  a->pvt_heap_size =
    (am->global_pvt_heap_size !=
     0) ? am->global_pvt_heap_size : SVM_PVT_MHEAP_SIZE;

  svm_region_init_args (a);

  error = vlib_call_init_function (vm, vlibsocket_init);

  return error;
}

void
vl_set_memory_region_name (const char *name)
{
  api_main_t *am = &api_main;
  am->region_name = name;
}

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