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authorDamjan Marion <damarion@cisco.com>2018-04-25 19:11:15 +0200
committerNeale Ranns <nranns@cisco.com>2018-04-27 11:35:07 +0000
commit164e5f8c63652028ecb9c3570e1ea8618b163071 (patch)
tree7423f5abbc61b761df9a679c7974f17613736020 /src/vpp-api/vom/tap_interface.cpp
parentaa682a39b76ee043f65313f23e134bf18fe7a47e (diff)
Move VOM to extras/vom
Change-Id: Iea174f03dfba3bd06024db0f0cc373532300dcae Signed-off-by: Damjan Marion <damarion@cisco.com>
Diffstat (limited to 'src/vpp-api/vom/tap_interface.cpp')
-rw-r--r--src/vpp-api/vom/tap_interface.cpp151
1 files changed, 0 insertions, 151 deletions
diff --git a/src/vpp-api/vom/tap_interface.cpp b/src/vpp-api/vom/tap_interface.cpp
deleted file mode 100644
index d7f16f5c132..00000000000
--- a/src/vpp-api/vom/tap_interface.cpp
+++ /dev/null
@@ -1,151 +0,0 @@
-/*
- * Copyright (c) 2017 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 "vom/tap_interface.hpp"
-#include "vom/tap_interface_cmds.hpp"
-
-#include <vapi/vpe.api.vapi.hpp>
-
-namespace VOM {
-tap_interface::event_handler tap_interface::m_evh;
-
-/**
- * Construct a new object matching the desried state
- */
-tap_interface::tap_interface(const std::string& name,
- admin_state_t state,
- route::prefix_t prefix)
- : interface(name, type_t::TAP, state)
- , m_prefix(prefix)
- , m_l2_address(l2_address_t::ZERO)
-{
-}
-
-tap_interface::tap_interface(const std::string& name,
- admin_state_t state,
- route::prefix_t prefix,
- const l2_address_t& l2_address)
- : interface(name, type_t::TAP, state)
- , m_prefix(prefix)
- , m_l2_address(l2_address)
-{
-}
-
-tap_interface::~tap_interface()
-{
- sweep();
- release();
-}
-
-tap_interface::tap_interface(const tap_interface& o)
- : interface(o)
- , m_prefix(o.m_prefix)
- , m_l2_address(o.m_l2_address)
-{
-}
-
-std::queue<cmd*>&
-tap_interface::mk_create_cmd(std::queue<cmd*>& q)
-{
- q.push(
- new tap_interface_cmds::create_cmd(m_hdl, name(), m_prefix, m_l2_address));
-
- return (q);
-}
-
-std::queue<cmd*>&
-tap_interface::mk_delete_cmd(std::queue<cmd*>& q)
-{
- q.push(new tap_interface_cmds::delete_cmd(m_hdl));
-
- return (q);
-}
-
-std::shared_ptr<tap_interface>
-tap_interface::singular() const
-{
- return std::dynamic_pointer_cast<tap_interface>(singular_i());
-}
-
-std::shared_ptr<interface>
-tap_interface::singular_i() const
-{
- return m_db.find_or_add(name(), *this);
-}
-
-void
-tap_interface::event_handler::handle_populate(const client_db::key_t& key)
-{
- /*
- * dump VPP current states
- */
- std::shared_ptr<tap_interface_cmds::dump_cmd> cmd =
- std::make_shared<tap_interface_cmds::dump_cmd>();
-
- HW::enqueue(cmd);
- HW::write();
-
- for (auto& record : *cmd) {
- auto& payload = record.get_payload();
-
- std::string name = reinterpret_cast<const char*>(payload.dev_name);
-
- tap_interface itf(name, interface::admin_state_t::UP,
- route::prefix_t::ZERO);
-
- VOM_LOG(log_level_t::DEBUG) << "tap-dump: " << itf.to_string();
-
- /*
- * Write each of the discovered interfaces into the OM,
- * but disable the HW Command q whilst we do, so that no
- * commands are sent to VPP
- */
- OM::commit(key, itf);
- }
-}
-
-tap_interface::event_handler::event_handler()
-{
- OM::register_listener(this);
- inspect::register_handler({ "tap" }, "tap_interfaces", this);
-}
-
-void
-tap_interface::event_handler::handle_replay()
-{
- // It will be replayed by interface handler
-}
-
-dependency_t
-tap_interface::event_handler::order() const
-{
- return (dependency_t::INTERFACE);
-}
-
-void
-tap_interface::event_handler::show(std::ostream& os)
-{
- // dumped by the interface handler
-}
-
-}; // namespace VOM
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "mozilla")
- * End:
- */
a> 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 
/*
 * Copyright (c) 2017 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 <vnet/session/segment_manager.h>
#include <vnet/session/session.h>
#include <vnet/session/application.h>

segment_manager_main_t segment_manager_main;

/**
 * Counter used to build segment names
 */
static u32 segment_name_counter = 0;

/**
 * Default fifo and segment size. TODO config.
 */
static u32 default_fifo_size = 1 << 12;
static u32 default_segment_size = 1 << 20;
static u32 default_app_evt_queue_size = 128;

segment_manager_properties_t *
segment_manager_properties_get (segment_manager_t * sm)
{
  app_worker_t *app_wrk = app_worker_get (sm->app_wrk_index);
  return application_get_segment_manager_properties (app_wrk->app_index);
}

segment_manager_properties_t *
segment_manager_properties_init (segment_manager_properties_t * props)
{
  props->add_segment_size = default_segment_size;
  props->rx_fifo_size = default_fifo_size;
  props->tx_fifo_size = default_fifo_size;
  props->evt_q_size = default_app_evt_queue_size;
  return props;
}

static u8
segment_manager_app_detached (segment_manager_t * sm)
{
  return (sm->app_wrk_index == SEGMENT_MANAGER_INVALID_APP_INDEX);
}

void
segment_manager_app_detach (segment_manager_t * sm)
{
  sm->app_wrk_index = SEGMENT_MANAGER_INVALID_APP_INDEX;
}

always_inline u32
segment_manager_segment_index (segment_manager_t * sm,
			       svm_fifo_segment_private_t * seg)
{
  return (seg - sm->segments);
}

/**
 * Remove segment without lock
 */
void
segment_manager_del_segment (segment_manager_t * sm,
			     svm_fifo_segment_private_t * fs)
{
  segment_manager_main_t *smm = &segment_manager_main;

  if (ssvm_type (&fs->ssvm) != SSVM_SEGMENT_PRIVATE)
    clib_valloc_free (&smm->va_allocator, fs->ssvm.requested_va);

  ssvm_delete (&fs->ssvm);

  if (CLIB_DEBUG)
    clib_memset (fs, 0xfb, sizeof (*fs));
  pool_put (sm->segments, fs);
}

/**
 * Removes segment after acquiring writer lock
 */
static inline void
segment_manager_lock_and_del_segment (segment_manager_t * sm, u32 fs_index)
{
  svm_fifo_segment_private_t *fs;
  u8 is_prealloc;

  clib_rwlock_writer_lock (&sm->segments_rwlock);
  fs = segment_manager_get_segment (sm, fs_index);
  is_prealloc = svm_fifo_segment_flags (fs) & FIFO_SEGMENT_F_IS_PREALLOCATED;
  if (is_prealloc && !segment_manager_app_detached (sm))
    {
      clib_rwlock_writer_unlock (&sm->segments_rwlock);
      return;
    }

  segment_manager_del_segment (sm, fs);
  clib_rwlock_writer_unlock (&sm->segments_rwlock);
}

/**
 * Reads a segment from the segment manager's pool without lock
 */
svm_fifo_segment_private_t *
segment_manager_get_segment (segment_manager_t * sm, u32 segment_index)
{
  return pool_elt_at_index (sm->segments, segment_index);
}

u64
segment_manager_segment_handle (segment_manager_t * sm,
				svm_fifo_segment_private_t * segment)
{
  u32 segment_index = segment_manager_segment_index (sm, segment);
  return (((u64) segment_manager_index (sm) << 32) | segment_index);
}

void
segment_manager_parse_segment_handle (u64 segment_handle, u32 * sm_index,
				      u32 * segment_index)
{
  *sm_index = segment_handle >> 32;
  *segment_index = segment_handle & 0xFFFFFFFF;
}

svm_fifo_segment_private_t *
segment_manager_get_segment_w_handle (u64 segment_handle)
{
  u32 sm_index, segment_index;
  segment_manager_t *sm;

  segment_manager_parse_segment_handle (segment_handle, &sm_index,
					&segment_index);
  sm = segment_manager_get (sm_index);
  if (!sm || pool_is_free_index (sm->segments, segment_index))
    return 0;
  return pool_elt_at_index (sm->segments, segment_index);
}

/**
 * Reads a segment from the segment manager's pool and acquires reader lock
 *
 * Caller must drop the reader's lock by calling
 * @ref segment_manager_segment_reader_unlock once it finishes working with
 * the segment.
 */
svm_fifo_segment_private_t *
segment_manager_get_segment_w_lock (segment_manager_t * sm, u32 segment_index)
{
  clib_rwlock_reader_lock (&sm->segments_rwlock);
  return pool_elt_at_index (sm->segments, segment_index);
}

void
segment_manager_segment_reader_unlock (segment_manager_t * sm)
{
  ASSERT (sm->segments_rwlock->n_readers > 0);
  clib_rwlock_reader_unlock (&sm->segments_rwlock);
}

void
segment_manager_segment_writer_unlock (segment_manager_t * sm)
{
  clib_rwlock_writer_unlock (&sm->segments_rwlock);
}

/**
 * Adds segment to segment manager's pool
 *
 * If needed a writer's lock is acquired before allocating a new segment
 * to avoid affecting any of the segments pool readers.
 */
int
segment_manager_add_segment (segment_manager_t * sm, u32 segment_size)
{
  segment_manager_main_t *smm = &segment_manager_main;
  u32 rnd_margin = 128 << 10, seg_index, page_size;
  segment_manager_properties_t *props;
  uword baseva = (uword) ~ 0ULL, alloc_size;
  svm_fifo_segment_private_t *seg;
  u8 *seg_name;
  int rv;

  props = segment_manager_properties_get (sm);

  /* Not configured for addition of new segments and not first */
  if (!props->add_segment && !segment_size)
    {
      clib_warning ("cannot allocate new segment");
      return VNET_API_ERROR_INVALID_VALUE;
    }

  /*
   * Allocate fifo segment and lock if needed
   */
  if (vlib_num_workers ())
    {
      clib_rwlock_writer_lock (&sm->segments_rwlock);
      pool_get (sm->segments, seg);
    }
  else
    {
      pool_get (sm->segments, seg);
    }
  clib_memset (seg, 0, sizeof (*seg));

  /*
   * Initialize ssvm segment and svm fifo private header
   */
  segment_size = segment_size ? segment_size : props->add_segment_size;
  page_size = clib_mem_get_page_size ();
  segment_size = (segment_size + page_size - 1) & ~(page_size - 1);
  if (props->segment_type != SSVM_SEGMENT_PRIVATE)
    {
      seg_name = format (0, "%d-%d%c", getpid (), segment_name_counter++, 0);
      alloc_size = (uword) segment_size + rnd_margin;
      baseva = clib_valloc_alloc (&smm->va_allocator, alloc_size, 0);
      if (!baseva)
	{
	  clib_warning ("out of space for segments");
	  return -1;
	}
    }
  else
    seg_name = format (0, "%s%c", "process-private-segment", 0);

  seg->ssvm.ssvm_size = segment_size;
  seg->ssvm.name = seg_name;
  seg->ssvm.requested_va = baseva;

  if ((rv = ssvm_master_init (&seg->ssvm, props->segment_type)))
    {
      clib_warning ("svm_master_init ('%v', %u) failed", seg_name,
		    segment_size);

      if (props->segment_type != SSVM_SEGMENT_PRIVATE)
	clib_valloc_free (&smm->va_allocator, baseva);
      pool_put (sm->segments, seg);
      return (rv);
    }

  svm_fifo_segment_init (seg);

  /*
   * Save segment index before dropping lock, if any held
   */
  seg_index = seg - sm->segments;

  if (vlib_num_workers ())
    clib_rwlock_writer_unlock (&sm->segments_rwlock);

  return seg_index;
}

segment_manager_t *
segment_manager_new ()
{
  segment_manager_main_t *smm = &segment_manager_main;
  segment_manager_t *sm;
  pool_get (smm->segment_managers, sm);
  clib_memset (sm, 0, sizeof (*sm));
  clib_rwlock_init (&sm->segments_rwlock);
  return sm;
}

/**
 * Initializes segment manager based on options provided.
 * Returns error if ssvm segment(s) allocation fails.
 */
int
segment_manager_init (segment_manager_t * sm, u32 first_seg_size,
		      u32 prealloc_fifo_pairs)
{
  u32 rx_fifo_size, tx_fifo_size, pair_size;
  u32 rx_rounded_data_size, tx_rounded_data_size;
  u64 approx_total_size, max_seg_size = ((u64) 1 << 32) - (128 << 10);
  segment_manager_properties_t *props;
  svm_fifo_segment_private_t *segment;
  u32 approx_segment_count;
  int seg_index, i;

  props = segment_manager_properties_get (sm);
  first_seg_size = clib_max (first_seg_size, default_segment_size);

  if (prealloc_fifo_pairs)
    {
      /* Figure out how many segments should be preallocated */
      rx_rounded_data_size = (1 << (max_log2 (props->rx_fifo_size)));
      tx_rounded_data_size = (1 << (max_log2 (props->tx_fifo_size)));

      rx_fifo_size = sizeof (svm_fifo_t) + rx_rounded_data_size;
      tx_fifo_size = sizeof (svm_fifo_t) + tx_rounded_data_size;
      pair_size = rx_fifo_size + tx_fifo_size;

      approx_total_size = (u64) prealloc_fifo_pairs *pair_size;
      if (first_seg_size > approx_total_size)
	max_seg_size = first_seg_size;
      approx_segment_count = (approx_total_size + (max_seg_size - 1))
	/ max_seg_size;

      /* Allocate the segments */
      for (i = 0; i < approx_segment_count + 1; i++)
	{
	  seg_index = segment_manager_add_segment (sm, max_seg_size);
	  if (seg_index < 0)
	    {
	      clib_warning ("Failed to preallocate segment %d", i);
	      return seg_index;
	    }

	  segment = segment_manager_get_segment (sm, seg_index);
	  if (i == 0)
	    sm->event_queue = segment_manager_alloc_queue (segment, props);

	  svm_fifo_segment_preallocate_fifo_pairs (segment,
						   props->rx_fifo_size,
						   props->tx_fifo_size,
						   &prealloc_fifo_pairs);
	  svm_fifo_segment_flags (segment) = FIFO_SEGMENT_F_IS_PREALLOCATED;
	  if (prealloc_fifo_pairs == 0)
	    break;
	}
    }
  else
    {
      seg_index = segment_manager_add_segment (sm, first_seg_size);
      if (seg_index)
	{
	  clib_warning ("Failed to allocate segment");
	  return seg_index;
	}
      segment = segment_manager_get_segment (sm, seg_index);
      sm->event_queue = segment_manager_alloc_queue (segment, props);
    }

  return 0;
}

u8
segment_manager_has_fifos (segment_manager_t * sm)
{
  svm_fifo_segment_private_t *seg;
  u8 first = 1;

  /* *INDENT-OFF* */
  segment_manager_foreach_segment_w_lock (seg, sm, ({
    if (CLIB_DEBUG && !first && !svm_fifo_segment_has_fifos (seg)
	&& !(svm_fifo_segment_flags (seg) & FIFO_SEGMENT_F_IS_PREALLOCATED))
      {
	clib_warning ("segment %d has no fifos!",
	              segment_manager_segment_index (sm, seg));
	first = 0;
      }
    if (svm_fifo_segment_has_fifos (seg))
      {
	segment_manager_segment_reader_unlock (sm);
	return 1;
      }
  }));
  /* *INDENT-ON* */

  return 0;
}

/**
 * Initiate disconnects for all sessions 'owned' by a segment manager
 */
void
segment_manager_del_sessions (segment_manager_t * sm)
{
  svm_fifo_segment_private_t *fifo_segment;
  stream_session_t *session;
  svm_fifo_t *fifo;

  ASSERT (pool_elts (sm->segments) != 0);

  /* Across all fifo segments used by the server */
  /* *INDENT-OFF* */
  segment_manager_foreach_segment_w_lock (fifo_segment, sm, ({
    fifo = svm_fifo_segment_get_fifo_list (fifo_segment);

    /*
     * Remove any residual sessions from the session lookup table
     * Don't bother deleting the individual fifos, we're going to
     * throw away the fifo segment in a minute.
     */
    while (fifo)
      {
	if (fifo->ct_session_index != SVM_FIFO_INVALID_SESSION_INDEX)
	  {
	    svm_fifo_t *next = fifo->next;
	    application_local_session_disconnect_w_index (sm->app_wrk_index,
	                                                  fifo->ct_session_index);
	    fifo = next;
	    continue;
	  }
	session = session_get (fifo->master_session_index,
	                       fifo->master_thread_index);
	session_close (session);
	fifo = fifo->next;
      }

    /* Instead of removing the segment, test when cleaning up disconnected
     * sessions if the segment can be removed.
     */
  }));
  /* *INDENT-ON* */
}

/**
 * Removes segment manager.
 *
 * Since the fifos allocated in the segment keep backpointers to the sessions
 * prior to removing the segment, we call session disconnect. This
 * subsequently propagates into transport.
 */
void
segment_manager_del (segment_manager_t * sm)
{
  segment_manager_main_t *smm = &segment_manager_main;
  svm_fifo_segment_private_t *fifo_segment;

  ASSERT (!segment_manager_has_fifos (sm)
	  && segment_manager_app_detached (sm));

  /* If we have empty preallocated segments that haven't been removed, remove
   * them now. Apart from that, the first segment in the first segment manager
   * is not removed when all fifos are removed. It can only be removed when
   * the manager is explicitly deleted/detached by the app. */
  clib_rwlock_writer_lock (&sm->segments_rwlock);

  /* *INDENT-OFF* */
  pool_foreach (fifo_segment, sm->segments, ({
    segment_manager_del_segment (sm, fifo_segment);
  }));
  /* *INDENT-ON* */

  clib_rwlock_writer_unlock (&sm->segments_rwlock);

  clib_rwlock_free (&sm->segments_rwlock);
  if (CLIB_DEBUG)
    clib_memset (sm, 0xfe, sizeof (*sm));
  pool_put (smm->segment_managers, sm);
}

void
segment_manager_init_del (segment_manager_t * sm)
{
  segment_manager_app_detach (sm);
  if (segment_manager_has_fifos (sm))
    segment_manager_del_sessions (sm);
  else
    {
      ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
      segment_manager_del (sm);
    }
}

int
segment_manager_try_alloc_fifos (svm_fifo_segment_private_t * fifo_segment,
				 u32 rx_fifo_size, u32 tx_fifo_size,
				 svm_fifo_t ** rx_fifo, svm_fifo_t ** tx_fifo)
{
  rx_fifo_size = clib_max (rx_fifo_size, default_fifo_size);
  *rx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, rx_fifo_size,
					  FIFO_SEGMENT_RX_FREELIST);

  tx_fifo_size = clib_max (tx_fifo_size, default_fifo_size);
  *tx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, tx_fifo_size,
					  FIFO_SEGMENT_TX_FREELIST);

  if (*rx_fifo == 0)
    {
      /* This would be very odd, but handle it... */
      if (*tx_fifo != 0)
	{
	  svm_fifo_segment_free_fifo (fifo_segment, *tx_fifo,
				      FIFO_SEGMENT_TX_FREELIST);
	  *tx_fifo = 0;
	}
      return -1;
    }
  if (*tx_fifo == 0)
    {
      if (*rx_fifo != 0)
	{
	  svm_fifo_segment_free_fifo (fifo_segment, *rx_fifo,
				      FIFO_SEGMENT_RX_FREELIST);
	  *rx_fifo = 0;
	}
      return -1;
    }

  return 0;
}

int
segment_manager_alloc_session_fifos (segment_manager_t * sm,
				     svm_fifo_t ** rx_fifo,
				     svm_fifo_t ** tx_fifo,
				     u32 * fifo_segment_index)
{
  svm_fifo_segment_private_t *fifo_segment = 0;
  int alloc_fail = 1, rv = 0, new_fs_index;
  segment_manager_properties_t *props;
  u8 added_a_segment = 0;
  u64 segment_handle;
  u32 sm_index;

  props = segment_manager_properties_get (sm);

  /*
   * Find the first free segment to allocate the fifos in
   */

  /* *INDENT-OFF* */
  segment_manager_foreach_segment_w_lock (fifo_segment, sm, ({
    alloc_fail = segment_manager_try_alloc_fifos (fifo_segment,
                                                  props->rx_fifo_size,
                                                  props->tx_fifo_size,
                                                  rx_fifo, tx_fifo);
    /* Exit with lock held, drop it after notifying app */
    if (!alloc_fail)
      goto alloc_success;
  }));
  /* *INDENT-ON* */

alloc_check:

  if (!alloc_fail)
    {

    alloc_success:

      ASSERT (rx_fifo && tx_fifo);
      sm_index = segment_manager_index (sm);
      *fifo_segment_index = segment_manager_segment_index (sm, fifo_segment);
      (*tx_fifo)->segment_manager = sm_index;
      (*rx_fifo)->segment_manager = sm_index;
      (*tx_fifo)->segment_index = *fifo_segment_index;
      (*rx_fifo)->segment_index = *fifo_segment_index;

      if (added_a_segment)
	{
	  segment_handle = segment_manager_segment_handle (sm, fifo_segment);
	  rv = app_worker_add_segment_notify (sm->app_wrk_index,
					      segment_handle);
	}
      /* Drop the lock after app is notified */
      segment_manager_segment_reader_unlock (sm);
      return rv;
    }

  /*
   * Allocation failed, see if we can add a new segment
   */
  if (props->add_segment)
    {
      if (added_a_segment)
	{
	  clib_warning ("Added a segment, still can't allocate a fifo");
	  segment_manager_segment_reader_unlock (sm);
	  return SESSION_ERROR_NEW_SEG_NO_SPACE;
	}
      if ((new_fs_index = segment_manager_add_segment (sm, 0)) < 0)
	{
	  clib_warning ("Failed to add new segment");
	  return SESSION_ERROR_SEG_CREATE;
	}
      fifo_segment = segment_manager_get_segment_w_lock (sm, new_fs_index);
      alloc_fail = segment_manager_try_alloc_fifos (fifo_segment,
						    props->rx_fifo_size,
						    props->tx_fifo_size,
						    rx_fifo, tx_fifo);
      added_a_segment = 1;
      goto alloc_check;
    }
  else
    {
      clib_warning ("Can't add new seg and no space to allocate fifos!");
      return SESSION_ERROR_NO_SPACE;
    }
}

void
segment_manager_dealloc_fifos (u32 segment_index, svm_fifo_t * rx_fifo,
			       svm_fifo_t * tx_fifo)
{
  svm_fifo_segment_private_t *fifo_segment;
  segment_manager_t *sm;

  if (!rx_fifo || !tx_fifo)
    return;

  /* It's possible to have no segment manager if the session was removed
   * as result of a detach. */
  if (!(sm = segment_manager_get_if_valid (rx_fifo->segment_manager)))
    return;

  fifo_segment = segment_manager_get_segment_w_lock (sm, segment_index);
  svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
			      FIFO_SEGMENT_RX_FREELIST);
  svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
			      FIFO_SEGMENT_TX_FREELIST);

  /*
   * Try to remove svm segment if it has no fifos. This can be done only if
   * the segment is not the first in the segment manager or if it is first
   * and it is not protected. Moreover, if the segment is first and the app
   * has detached from the segment manager, remove the segment manager.
   */
  if (!svm_fifo_segment_has_fifos (fifo_segment))
    {
      segment_manager_segment_reader_unlock (sm);

      /* Remove segment if it holds no fifos or first but not protected */
      if (segment_index != 0 || !sm->first_is_protected)
	segment_manager_lock_and_del_segment (sm, segment_index);

      /* Remove segment manager if no sessions and detached from app */
      if (segment_manager_app_detached (sm)
	  && !segment_manager_has_fifos (sm))
	{
	  segment_manager_del (sm);
	}
    }
  else
    segment_manager_segment_reader_unlock (sm);
}

u32
segment_manager_evt_q_expected_size (u32 q_len)
{
  u32 fifo_evt_size, notif_q_size, q_hdrs;
  u32 msg_q_sz, fifo_evt_ring_sz, session_ntf_ring_sz;

  fifo_evt_size = 1 << max_log2 (sizeof (session_event_t));
  notif_q_size = clib_max (16, q_len >> 4);

  msg_q_sz = q_len * sizeof (svm_msg_q_msg_t);
  fifo_evt_ring_sz = q_len * fifo_evt_size;
  session_ntf_ring_sz = notif_q_size * 256;
  q_hdrs = sizeof (svm_queue_t) + sizeof (svm_msg_q_t);

  return (msg_q_sz + fifo_evt_ring_sz + session_ntf_ring_sz + q_hdrs);
}

/**
 * Allocates shm queue in the first segment
 *
 * Must be called with lock held
 */
svm_msg_q_t *
segment_manager_alloc_queue (svm_fifo_segment_private_t * segment,
			     segment_manager_properties_t * props)
{
  u32 fifo_evt_size, session_evt_size = 256, notif_q_size;
  svm_msg_q_cfg_t _cfg, *cfg = &_cfg;
  svm_msg_q_t *q;
  void *oldheap;

  fifo_evt_size = sizeof (session_event_t);
  notif_q_size = clib_max (16, props->evt_q_size >> 4);
  /* *INDENT-OFF* */
  svm_msg_q_ring_cfg_t rc[SESSION_MQ_N_RINGS] = {
    {props->evt_q_size, fifo_evt_size, 0},
    {notif_q_size, session_evt_size, 0}
  };
  /* *INDENT-ON* */
  cfg->consumer_pid = 0;
  cfg->n_rings = 2;
  cfg->q_nitems = props->evt_q_size;
  cfg->ring_cfgs = rc;

  oldheap = ssvm_push_heap (segment->ssvm.sh);
  q = svm_msg_q_alloc (cfg);
  ssvm_pop_heap (oldheap);

  if (props->use_mq_eventfd)
    {
      if (svm_msg_q_alloc_producer_eventfd (q))
	clib_warning ("failed to alloc eventfd");
    }
  return q;
}

/**
 * Frees shm queue allocated in the first segment
 */
void
segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
{
  svm_fifo_segment_private_t *segment;
  ssvm_shared_header_t *sh;
  void *oldheap;

  ASSERT (!pool_is_free_index (sm->segments, 0));

  segment = segment_manager_get_segment_w_lock (sm, 0);
  sh = segment->ssvm.sh;

  oldheap = ssvm_push_heap (sh);
  svm_queue_free (q);
  ssvm_pop_heap (oldheap);
  segment_manager_segment_reader_unlock (sm);
}

/*
 * Init segment vm address allocator
 */
void
segment_manager_main_init (segment_manager_main_init_args_t * a)
{
  segment_manager_main_t *sm = &segment_manager_main;
  clib_valloc_chunk_t _ip, *ip = &_ip;

  ip->baseva = a->baseva;
  ip->size = a->size;

  clib_valloc_init (&sm->va_allocator, ip, 1 /* lock */ );
}

static clib_error_t *
segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
			 vlib_cli_command_t * cmd)
{
  segment_manager_main_t *smm = &segment_manager_main;
  svm_fifo_segment_private_t *seg;
  segment_manager_t *sm;
  u8 show_segments = 0, verbose = 0;
  char *address;
  size_t size;
  u32 active_fifos;
  u32 free_fifos;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "segments"))
	show_segments = 1;
      else if (unformat (input, "verbose"))
	verbose = 1;
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, input);
    }
  vlib_cli_output (vm, "%d segment managers allocated",
		   pool_elts (smm->segment_managers));
  if (verbose && pool_elts (smm->segment_managers))
    {
      vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
		       "Segments");

      /* *INDENT-OFF* */
      pool_foreach (sm, smm->segment_managers, ({
	vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index (sm),
			   sm->app_wrk_index, pool_elts (sm->segments));
      }));
      /* *INDENT-ON* */

    }
  if (show_segments)
    {
      vlib_cli_output (vm, "%-15s%15s%15s%15s%15s%15s", "Name", "Type",
		       "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");

      /* *INDENT-OFF* */
      pool_foreach (sm, smm->segment_managers, ({
	  segment_manager_foreach_segment_w_lock (seg, sm, ({
	    svm_fifo_segment_info (seg, &address, &size);
	    active_fifos = svm_fifo_segment_num_fifos (seg);
	    free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
	    vlib_cli_output (vm, "%-15v%15U%15llu%15u%15u%15llx",
			     ssvm_name (&seg->ssvm), format_svm_fifo_segment_type,
			     seg, size >> 20ULL, active_fifos, free_fifos,
			     address);
	    if (verbose)
	      vlib_cli_output (vm, "%U", format_svm_fifo_segment, seg, verbose);
	  }));
      }));
      /* *INDENT-ON* */

    }
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (segment_manager_show_command, static) =
{
  .path = "show segment-manager",
  .short_help = "show segment-manager [segments][verbose]",
  .function = segment_manager_show_fn,
};
/* *INDENT-ON* */

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