src/vnet/session/segment_manager.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <vnet/session/segment_manager.h>
  17 #include <vnet/session/session.h>
  18 #include <vnet/session/application.h>
  19
  20 /**
  21  * Counter used to build segment names
  22  */
  23 u32 segment_name_counter = 0;
  24
  25 /**
  26  * Pool of segment managers
  27  */
  28 segment_manager_t *segment_managers = 0;
  29
  30 /**
  31  * Process private segment index
  32  */
  33 u32 *private_segment_indices;
  34
  35 /**
  36  * Default fifo and segment size. TODO config.
  37  */
  38 u32 default_fifo_size = 1 << 16;
  39 u32 default_segment_size = 1 << 20;
  40
  41 void
  42 segment_manager_get_segment_info (u32 index, u8 ** name, u32 * size)
  43 {
  44   svm_fifo_segment_private_t *s;
  45   s = svm_fifo_segment_get_segment (index);
  46   *name = s->h->segment_name;
  47   *size = s->ssvm.ssvm_size;
  48 }
  49
  50 always_inline int
  51 session_manager_add_segment_i (segment_manager_t * sm, u32 segment_size,
  52                                u8 * segment_name)
  53 {
  54   svm_fifo_segment_create_args_t _ca, *ca = &_ca;
  55   int rv;
  56
  57   memset (ca, 0, sizeof (*ca));
  58
  59   if (!sm->properties->use_private_segment)
  60     {
  61       ca->segment_name = (char *) segment_name;
  62       ca->segment_size = segment_size;
  63       ca->rx_fifo_size = sm->properties->rx_fifo_size;
  64       ca->tx_fifo_size = sm->properties->tx_fifo_size;
  65       ca->preallocated_fifo_pairs = sm->properties->preallocated_fifo_pairs;
  66
  67       rv = svm_fifo_segment_create (ca);
  68       if (rv)
  69         {
  70           clib_warning ("svm_fifo_segment_create ('%s', %d) failed",
  71                         ca->segment_name, ca->segment_size);
  72           return VNET_API_ERROR_SVM_SEGMENT_CREATE_FAIL;
  73         }
  74     }
  75   else
  76     {
  77       ca->segment_name = "process-private-segment";
  78       ca->segment_size = ~0;
  79       ca->rx_fifo_size = sm->properties->rx_fifo_size;
  80       ca->tx_fifo_size = sm->properties->tx_fifo_size;
  81       ca->preallocated_fifo_pairs = sm->properties->preallocated_fifo_pairs;
  82       ca->private_segment_count = sm->properties->private_segment_count;
  83       ca->private_segment_size = sm->properties->private_segment_size;
  84
  85       if (svm_fifo_segment_create_process_private (ca))
  86         clib_warning ("Failed to create process private segment");
  87
  88       ASSERT (vec_len (ca->new_segment_indices));
  89     }
  90   vec_append (sm->segment_indices, ca->new_segment_indices);
  91   vec_free (ca->new_segment_indices);
  92   return 0;
  93 }
  94
  95 int
  96 session_manager_add_segment (segment_manager_t * sm)
  97 {
  98   u8 *segment_name;
  99   svm_fifo_segment_create_args_t _ca, *ca = &_ca;
 100   u32 add_segment_size;
 101   int rv;
 102
 103   memset (ca, 0, sizeof (*ca));
 104   segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
 105   add_segment_size = sm->properties->add_segment_size ?
 106     sm->properties->add_segment_size : default_segment_size;
 107
 108   rv = session_manager_add_segment_i (sm, add_segment_size, segment_name);
 109   vec_free (segment_name);
 110   return rv;
 111 }
 112
 113 int
 114 session_manager_add_first_segment (segment_manager_t * sm, u32 segment_size)
 115 {
 116   u8 *segment_name;
 117   int rv;
 118
 119   segment_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
 120   rv = session_manager_add_segment_i (sm, segment_size, segment_name);
 121   vec_free (segment_name);
 122   return rv;
 123 }
 124
 125 segment_manager_t *
 126 segment_manager_new ()
 127 {
 128   segment_manager_t *sm;
 129   pool_get (segment_managers, sm);
 130   memset (sm, 0, sizeof (*sm));
 131   return sm;
 132 }
 133
 134 /**
 135  * Initializes segment manager based on options provided.
 136  * Returns error if svm segment allocation fails.
 137  */
 138 int
 139 segment_manager_init (segment_manager_t * sm,
 140                       segment_manager_properties_t * properties,
 141                       u32 first_seg_size)
 142 {
 143   int rv;
 144
 145   /* app allocates these */
 146   sm->properties = properties;
 147
 148   first_seg_size = first_seg_size > 0 ? first_seg_size : default_segment_size;
 149
 150   rv = session_manager_add_first_segment (sm, first_seg_size);
 151   if (rv)
 152     {
 153       clib_warning ("Failed to allocate segment");
 154       return rv;
 155     }
 156
 157   clib_spinlock_init (&sm->lockp);
 158   return 0;
 159 }
 160
 161 u8
 162 segment_manager_has_fifos (segment_manager_t * sm)
 163 {
 164   svm_fifo_segment_private_t *segment;
 165   /* Weird, but handle it */
 166   if (vec_len (sm->segment_indices) == 0)
 167     return 0;
 168   if (vec_len (sm->segment_indices) == 1)
 169     {
 170       segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 171       if (svm_fifo_segment_num_fifos (segment) == 0)
 172         return 0;
 173     }
 174   if (CLIB_DEBUG)
 175     {
 176       svm_fifo_segment_private_t *segment;
 177       int i;
 178       for (i = 1; i < vec_len (sm->segment_indices); i++)
 179         {
 180           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 181           if (!svm_fifo_segment_has_fifos (segment))
 182             clib_warning ("segment has no fifos!");
 183         }
 184     }
 185   return 1;
 186 }
 187
 188 static void
 189 segment_manager_del_segment (segment_manager_t * sm, u32 segment_index)
 190 {
 191   svm_fifo_segment_private_t *fifo_segment;
 192   u32 svm_segment_index;
 193   clib_spinlock_lock (&sm->lockp);
 194   svm_segment_index = sm->segment_indices[segment_index];
 195   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 196   svm_fifo_segment_delete (fifo_segment);
 197   vec_del1 (sm->segment_indices, segment_index);
 198   clib_spinlock_unlock (&sm->lockp);
 199 }
 200
 201 /**
 202  * Initiate disconnects for all sessions 'owned' by a segment manager
 203  */
 204 void
 205 segment_manager_del_sessions (segment_manager_t * sm)
 206 {
 207   int j;
 208   svm_fifo_segment_private_t *fifo_segment;
 209   svm_fifo_t *fifo;
 210
 211   ASSERT (vec_len (sm->segment_indices));
 212
 213   /* Across all fifo segments used by the server */
 214   for (j = 0; j < vec_len (sm->segment_indices); j++)
 215     {
 216       fifo_segment = svm_fifo_segment_get_segment (sm->segment_indices[j]);
 217       fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
 218
 219       /*
 220        * Remove any residual sessions from the session lookup table
 221        * Don't bother deleting the individual fifos, we're going to
 222        * throw away the fifo segment in a minute.
 223        */
 224       while (fifo)
 225         {
 226           u32 session_index, thread_index;
 227           stream_session_t *session;
 228
 229           session_index = fifo->master_session_index;
 230           thread_index = fifo->master_thread_index;
 231           session = stream_session_get (session_index, thread_index);
 232
 233           /* Instead of directly removing the session call disconnect */
 234           if (session->session_state != SESSION_STATE_CLOSED)
 235             {
 236               session->session_state = SESSION_STATE_CLOSED;
 237               session_send_session_evt_to_thread (stream_session_handle
 238                                                   (session),
 239                                                   FIFO_EVENT_DISCONNECT,
 240                                                   thread_index);
 241             }
 242           fifo = fifo->next;
 243         }
 244
 245       /* Instead of removing the segment, test when cleaning up disconnected
 246        * sessions if the segment can be removed.
 247        */
 248     }
 249 }
 250
 251 /**
 252  * Removes segment manager.
 253  *
 254  * Since the fifos allocated in the segment keep backpointers to the sessions
 255  * prior to removing the segment, we call session disconnect. This
 256  * subsequently propages into transport.
 257  */
 258 void
 259 segment_manager_del (segment_manager_t * sm)
 260 {
 261
 262   ASSERT (vec_len (sm->segment_indices) <= 1);
 263   if (vec_len (sm->segment_indices))
 264     {
 265       /* The first segment in the first segment manager is not removed when
 266        * all fifos are removed. It can only be removed when the manager is
 267        * explicitly deleted/detached by the app. */
 268       if (CLIB_DEBUG)
 269         {
 270           svm_fifo_segment_private_t *fifo_segment;
 271           fifo_segment =
 272             svm_fifo_segment_get_segment (sm->segment_indices[0]);
 273           ASSERT (!svm_fifo_segment_has_fifos (fifo_segment));
 274         }
 275       segment_manager_del_segment (sm, 0);
 276     }
 277   clib_spinlock_free (&sm->lockp);
 278   if (CLIB_DEBUG)
 279     memset (sm, 0xfe, sizeof (*sm));
 280   pool_put (segment_managers, sm);
 281 }
 282
 283 void
 284 segment_manager_init_del (segment_manager_t * sm)
 285 {
 286   if (segment_manager_has_fifos (sm))
 287     segment_manager_del_sessions (sm);
 288   else
 289     {
 290       ASSERT (!sm->first_is_protected
 291               || sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX);
 292       segment_manager_del (sm);
 293     }
 294 }
 295
 296 int
 297 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 298                                      svm_fifo_t ** server_rx_fifo,
 299                                      svm_fifo_t ** server_tx_fifo,
 300                                      u32 * fifo_segment_index)
 301 {
 302   svm_fifo_segment_private_t *fifo_segment;
 303   u32 fifo_size, sm_index;
 304   u8 added_a_segment = 0;
 305   int i;
 306
 307   ASSERT (vec_len (sm->segment_indices));
 308
 309   /* Make sure we don't have multiple threads trying to allocate segments
 310    * at the same time. */
 311   clib_spinlock_lock (&sm->lockp);
 312
 313   /* Allocate svm fifos */
 314 again:
 315   for (i = 0; i < vec_len (sm->segment_indices); i++)
 316     {
 317       *fifo_segment_index = sm->segment_indices[i];
 318       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 319
 320       fifo_size = sm->properties->rx_fifo_size;
 321       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 322       *server_rx_fifo =
 323         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 324                                      FIFO_SEGMENT_RX_FREELIST);
 325
 326       fifo_size = sm->properties->tx_fifo_size;
 327       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 328       *server_tx_fifo =
 329         svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 330                                      FIFO_SEGMENT_TX_FREELIST);
 331
 332       if (*server_rx_fifo == 0)
 333         {
 334           /* This would be very odd, but handle it... */
 335           if (*server_tx_fifo != 0)
 336             {
 337               svm_fifo_segment_free_fifo (fifo_segment, *server_tx_fifo,
 338                                           FIFO_SEGMENT_TX_FREELIST);
 339               *server_tx_fifo = 0;
 340             }
 341           continue;
 342         }
 343       if (*server_tx_fifo == 0)
 344         {
 345           if (*server_rx_fifo != 0)
 346             {
 347               svm_fifo_segment_free_fifo (fifo_segment, *server_rx_fifo,
 348                                           FIFO_SEGMENT_RX_FREELIST);
 349               *server_rx_fifo = 0;
 350             }
 351           continue;
 352         }
 353       break;
 354     }
 355
 356   /* See if we're supposed to create another segment */
 357   if (*server_rx_fifo == 0)
 358     {
 359       if (sm->properties->add_segment && !sm->properties->use_private_segment)
 360         {
 361           if (added_a_segment)
 362             {
 363               clib_warning ("added a segment, still can't allocate a fifo");
 364               clib_spinlock_unlock (&sm->lockp);
 365               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 366             }
 367
 368           if (session_manager_add_segment (sm))
 369             {
 370               clib_spinlock_unlock (&sm->lockp);
 371               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 372             }
 373
 374           added_a_segment = 1;
 375           goto again;
 376         }
 377       else
 378         {
 379           clib_warning ("No space to allocate fifos!");
 380           clib_spinlock_unlock (&sm->lockp);
 381           return SESSION_ERROR_NO_SPACE;
 382         }
 383     }
 384
 385   /* Backpointers to segment manager */
 386   sm_index = segment_manager_index (sm);
 387   (*server_tx_fifo)->segment_manager = sm_index;
 388   (*server_rx_fifo)->segment_manager = sm_index;
 389
 390   clib_spinlock_unlock (&sm->lockp);
 391
 392   if (added_a_segment)
 393     return application_add_segment_notify (sm->app_index,
 394                                            *fifo_segment_index);
 395
 396   return 0;
 397 }
 398
 399 void
 400 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 401                                svm_fifo_t * tx_fifo)
 402 {
 403   segment_manager_t *sm;
 404   svm_fifo_segment_private_t *fifo_segment;
 405   u32 i, segment_index = ~0;
 406   u8 is_first;
 407
 408   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 409
 410   /* It's possible to have no segment manager if the session was removed
 411    * as result of a detach. */
 412   if (!sm)
 413     return;
 414
 415   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 416   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 417                               FIFO_SEGMENT_RX_FREELIST);
 418   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 419                               FIFO_SEGMENT_TX_FREELIST);
 420
 421   /*
 422    * Try to remove svm segment if it has no fifos. This can be done only if
 423    * the segment is not the first in the segment manager or if it is first
 424    * and it is not protected. Moreover, if the segment is first and the app
 425    * has detached from the segment manager, remove the segment manager.
 426    */
 427   if (!svm_fifo_segment_has_fifos (fifo_segment))
 428     {
 429       is_first = sm->segment_indices[0] == svm_segment_index;
 430
 431       /* Remove segment if it holds no fifos or first but not protected */
 432       if (!is_first || !sm->first_is_protected)
 433         {
 434           /* Find the segment manager segment index */
 435           for (i = 0; i < vec_len (sm->segment_indices); i++)
 436             if (sm->segment_indices[i] == svm_segment_index)
 437               {
 438                 segment_index = i;
 439                 break;
 440               }
 441           ASSERT (segment_index != (u32) ~ 0);
 442           segment_manager_del_segment (sm, segment_index);
 443         }
 444
 445       /* Remove segment manager if no sessions and detached from app */
 446       if (sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX && is_first)
 447         segment_manager_del (sm);
 448     }
 449 }
 450
 451 /**
 452  * Allocates shm queue in the first segment
 453  */
 454 unix_shared_memory_queue_t *
 455 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 456 {
 457   ssvm_shared_header_t *sh;
 458   svm_fifo_segment_private_t *segment;
 459   unix_shared_memory_queue_t *q;
 460   void *oldheap;
 461
 462   ASSERT (sm->segment_indices != 0);
 463
 464   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 465   sh = segment->ssvm.sh;
 466
 467   oldheap = ssvm_push_heap (sh);
 468   q = unix_shared_memory_queue_init (queue_size,
 469                                      sizeof (session_fifo_event_t),
 470                                      0 /* consumer pid */ ,
 471                                      0 /* signal when queue non-empty */ );
 472   ssvm_pop_heap (oldheap);
 473   return q;
 474 }
 475
 476 /**
 477  * Frees shm queue allocated in the first segment
 478  */
 479 void
 480 segment_manager_dealloc_queue (segment_manager_t * sm,
 481                                unix_shared_memory_queue_t * q)
 482 {
 483   ssvm_shared_header_t *sh;
 484   svm_fifo_segment_private_t *segment;
 485   void *oldheap;
 486
 487   ASSERT (sm->segment_indices != 0);
 488
 489   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 490   sh = segment->ssvm.sh;
 491
 492   oldheap = ssvm_push_heap (sh);
 493   unix_shared_memory_queue_free (q);
 494   ssvm_pop_heap (oldheap);
 495 }
 496
 497 static clib_error_t *
 498 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 499                          vlib_cli_command_t * cmd)
 500 {
 501   svm_fifo_segment_private_t *segments, *seg;
 502   segment_manager_t *sm;
 503   u8 show_segments = 0, verbose = 0, *name;
 504   uword address;
 505   u64 size;
 506   u32 fifos;
 507   mheap_t *heap_header;
 508
 509   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 510     {
 511       if (unformat (input, "segments"))
 512         show_segments = 1;
 513       else if (unformat (input, "verbose"))
 514         verbose = 1;
 515       else
 516         return clib_error_return (0, "unknown input `%U'",
 517                                   format_unformat_error, input);
 518     }
 519   vlib_cli_output (vm, "%d segment managers allocated",
 520                    pool_elts (segment_managers));
 521   if (verbose && pool_elts (segment_managers))
 522     {
 523       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 524                        "Segments");
 525
 526       /* *INDENT-OFF* */
 527       pool_foreach (sm, segment_managers, ({
 528         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 529                            sm->app_index, vec_len (sm->segment_indices));
 530       }));
 531       /* *INDENT-ON* */
 532
 533     }
 534   if (show_segments)
 535     {
 536       segments = svm_fifo_segment_segments_pool ();
 537       vlib_cli_output (vm, "%d svm fifo segments allocated",
 538                        pool_elts (segments));
 539       vlib_cli_output (vm, "%-20s%=12s%=12s%=15s", "Name", "Size (M)",
 540                        "Fifos", "Address");
 541
 542       /* *INDENT-OFF* */
 543       pool_foreach (seg, segments, ({
 544         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 545           {
 546             address = pointer_to_uword (seg->ssvm.sh->heap);
 547             if (seg->h->flags & FIFO_SEGMENT_F_IS_MAIN_HEAP)
 548               name = format (0, "main heap");
 549             else
 550               name = format (0, "private heap");
 551             heap_header = mheap_header (seg->ssvm.sh->heap);
 552             size = heap_header->max_size;
 553           }
 554         else
 555           {
 556             address =  seg->ssvm.sh->ssvm_va;
 557             size = seg->ssvm.ssvm_size;
 558             name = seg->ssvm.sh->name;
 559           }
 560         fifos = svm_fifo_segment_num_fifos (seg);
 561         vlib_cli_output (vm, "%-20s%=12u%=12u%=15x", name, size << 20, fifos,
 562                          address);
 563         if (seg->h->flags & FIFO_SEGMENT_F_IS_PRIVATE)
 564           vec_free (name);
 565       }));
 566       /* *INDENT-ON* */
 567
 568     }
 569   return 0;
 570 }
 571
 572                           /* *INDENT-OFF* */
 573 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 574 {
 575   .path = "show segment-manager",
 576   .short_help = "show segment-manager [segments]",
 577   .function = segment_manager_show_fn,
 578 };
 579 /* *INDENT-ON* */
 580
 581 /*
 582  * fd.io coding-style-patch-verification: ON
 583  *
 584  * Local Variables:
 585  * eval: (c-set-style "gnu")
 586  * End:
 587  */