Initial commit of vpp code.

Change-Id: Ib246f1fbfce93274020ee93ce461e3d8bd8b9f17
Signed-off-by: Ed Warnicke <eaw@cisco.com>
diff --git a/vlib/vlib/main.c b/vlib/vlib/main.c
new file mode 100644
index 0000000..64bd3c0
--- /dev/null
+++ b/vlib/vlib/main.c
@@ -0,0 +1,1559 @@
+/*
+ * 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.
+ */
+/*
+ * main.c: main vector processing loop
+ *
+ * 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 <math.h>
+#include <vppinfra/format.h>
+#include <vlib/vlib.h>
+#include <vlib/threads.h>
+
+#include <vlib/unix/cj.h>
+
+CJ_GLOBAL_LOG_PROTOTYPE;
+
+
+//#define VLIB_ELOG_MAIN_LOOP 1
+
+/* Actually allocate a few extra slots of vector data to support
+   speculative vector enqueues which overflow vector data in next frame. */
+#define VLIB_FRAME_SIZE_ALLOC (VLIB_FRAME_SIZE + 4)
+
+always_inline u32
+vlib_frame_bytes (u32 n_scalar_bytes, u32 n_vector_bytes)
+{
+  u32 n_bytes;
+
+  /* Make room for vlib_frame_t plus scalar arguments. */
+  n_bytes = vlib_frame_vector_byte_offset (n_scalar_bytes);
+
+  /* Make room for vector arguments.
+     Allocate a few extra slots of vector data to support
+     speculative vector enqueues which overflow vector data in next frame. */
+#define VLIB_FRAME_SIZE_EXTRA 4
+  n_bytes += (VLIB_FRAME_SIZE + VLIB_FRAME_SIZE_EXTRA) * n_vector_bytes;
+
+  /* Magic number is first 32bit number after vector data.
+     Used to make sure that vector data is never overrun. */
+#define VLIB_FRAME_MAGIC (0xabadc0ed)
+  n_bytes += sizeof (u32);
+
+  /* Pad to cache line. */
+  n_bytes = round_pow2 (n_bytes, CLIB_CACHE_LINE_BYTES);
+
+  return n_bytes;
+}
+
+always_inline u32 *
+vlib_frame_find_magic (vlib_frame_t * f, vlib_node_t * node)
+{
+  void * p = f;
+
+  p += vlib_frame_vector_byte_offset (node->scalar_size);
+
+  p += (VLIB_FRAME_SIZE + VLIB_FRAME_SIZE_EXTRA) * node->vector_size;
+
+  return p;
+}
+
+static vlib_frame_size_t *
+get_frame_size_info (vlib_node_main_t * nm,
+		     u32 n_scalar_bytes, u32 n_vector_bytes)
+{
+  uword key = (n_scalar_bytes << 16) | n_vector_bytes;
+  uword * p, i;
+
+  p = hash_get (nm->frame_size_hash, key);
+  if (p)
+    i = p[0];
+  else
+    {
+      i = vec_len (nm->frame_sizes);
+      vec_validate (nm->frame_sizes, i);
+      hash_set (nm->frame_size_hash, key, i);
+    }
+
+  return vec_elt_at_index (nm->frame_sizes, i);
+}
+
+static u32
+vlib_frame_alloc_to_node (vlib_main_t * vm, u32 to_node_index, u32 frame_flags)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_frame_size_t * fs;
+  vlib_node_t * to_node;
+  vlib_frame_t * f;
+  u32 fi, l, n, scalar_size, vector_size;
+
+  to_node = vlib_get_node (vm, to_node_index);
+
+  scalar_size = to_node->scalar_size;
+  vector_size = to_node->vector_size;
+
+  fs = get_frame_size_info (nm, scalar_size, vector_size);
+  n = vlib_frame_bytes (scalar_size, vector_size);
+  if ((l = vec_len (fs->free_frame_indices)) > 0)
+    {
+      /* Allocate from end of free list. */
+      fi = fs->free_frame_indices[l - 1];
+      f = vlib_get_frame_no_check (vm, fi);
+      _vec_len (fs->free_frame_indices) = l - 1;
+    }
+  else
+    {
+      f = clib_mem_alloc_aligned_no_fail (n, CLIB_CACHE_LINE_BYTES);
+      f->cpu_index = vm->cpu_index;
+      fi = vlib_frame_index_no_check (vm, f);
+    }
+
+  /* Poison frame when debugging. */
+  if (CLIB_DEBUG > 0)
+    {
+      u32 save_cpu_index = f->cpu_index;
+
+      memset (f, 0xfe, n);
+
+      f->cpu_index = save_cpu_index;
+    }
+
+  /* Insert magic number. */
+  {
+    u32 * magic;
+
+    magic = vlib_frame_find_magic (f, to_node);
+    *magic = VLIB_FRAME_MAGIC;
+  }
+
+  f->flags = VLIB_FRAME_IS_ALLOCATED | frame_flags;
+  f->n_vectors = 0;
+  f->scalar_size = scalar_size;
+  f->vector_size = vector_size;
+
+  fs->n_alloc_frames += 1;
+
+  return fi;
+}
+
+/* Allocate a frame for from FROM_NODE to TO_NODE via TO_NEXT_INDEX.
+   Returns frame index. */
+static u32
+vlib_frame_alloc (vlib_main_t * vm, vlib_node_runtime_t * from_node_runtime, u32 to_next_index)
+{
+  vlib_node_t * from_node;
+
+  from_node = vlib_get_node (vm, from_node_runtime->node_index);
+  ASSERT (to_next_index < vec_len (from_node->next_nodes));
+
+  return vlib_frame_alloc_to_node (vm,
+				   from_node->next_nodes[to_next_index],
+				   /* frame_flags */ 0);
+}
+
+vlib_frame_t *
+vlib_get_frame_to_node (vlib_main_t * vm, u32 to_node_index)
+{
+  u32 fi = vlib_frame_alloc_to_node (vm, to_node_index,
+				     /* frame_flags */ VLIB_FRAME_FREE_AFTER_DISPATCH);
+  return vlib_get_frame (vm, fi);
+}
+
+void vlib_put_frame_to_node (vlib_main_t * vm, u32 to_node_index, vlib_frame_t * f)
+{
+  vlib_pending_frame_t * p;
+  vlib_node_t * to_node;
+
+  if (f->n_vectors == 0)
+    return;
+
+  to_node = vlib_get_node (vm, to_node_index);
+
+  vec_add2 (vm->node_main.pending_frames, p, 1);
+
+  f->flags |= VLIB_FRAME_PENDING;
+  p->frame_index = vlib_frame_index (vm, f);
+  p->node_runtime_index = to_node->runtime_index;
+  p->next_frame_index = VLIB_PENDING_FRAME_NO_NEXT_FRAME;
+}
+
+/* Free given frame. */
+void
+vlib_frame_free (vlib_main_t * vm,
+		 vlib_node_runtime_t * r,
+		 vlib_frame_t * f)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_node_t * node;
+  vlib_frame_size_t * fs;
+  u32 frame_index;
+  
+  ASSERT (f->flags & VLIB_FRAME_IS_ALLOCATED);
+
+  node = vlib_get_node (vm, r->node_index);
+  fs = get_frame_size_info (nm, node->scalar_size, node->vector_size);
+
+  frame_index = vlib_frame_index (vm, f);
+
+  ASSERT (f->flags & VLIB_FRAME_IS_ALLOCATED);
+
+  /* No next frames may point to freed frame. */
+  if (CLIB_DEBUG > 0)
+    {
+      vlib_next_frame_t * nf;
+      vec_foreach (nf, vm->node_main.next_frames)
+	ASSERT (nf->frame_index != frame_index);
+    }
+
+  f->flags &= ~VLIB_FRAME_IS_ALLOCATED;
+
+  vec_add1 (fs->free_frame_indices, frame_index);
+  ASSERT (fs->n_alloc_frames > 0);
+  fs->n_alloc_frames -= 1;
+}
+
+static clib_error_t *
+show_frame_stats (vlib_main_t * vm,
+		  unformat_input_t * input,
+		  vlib_cli_command_t * cmd)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_frame_size_t * fs;
+  
+  vlib_cli_output (vm, "%=6s%=12s%=12s", "Size", "# Alloc", "# Free");
+  vec_foreach (fs, nm->frame_sizes)
+    {
+      u32 n_alloc = fs->n_alloc_frames;
+      u32 n_free = vec_len (fs->free_frame_indices);
+
+      if (n_alloc + n_free > 0)
+	vlib_cli_output (vm, "%=6d%=12d%=12d",
+			 fs - nm->frame_sizes, n_alloc, n_free);
+    }
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (show_frame_stats_cli, static) = {
+  .path = "show vlib frame-allocation",
+  .short_help = "Show node dispatch frame statistics",
+  .function = show_frame_stats,
+};
+
+/* Change ownership of enqueue rights to given next node. */
+static void
+vlib_next_frame_change_ownership (vlib_main_t * vm,
+				  vlib_node_runtime_t * node_runtime,
+				  u32 next_index)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_next_frame_t * next_frame;
+  vlib_node_t * node, * next_node;
+
+  node = vec_elt (nm->nodes, node_runtime->node_index);
+
+  /* Only internal & input nodes are allowed to call other nodes. */
+  ASSERT (node->type == VLIB_NODE_TYPE_INTERNAL
+	  || node->type == VLIB_NODE_TYPE_INPUT
+	  || node->type == VLIB_NODE_TYPE_PROCESS);
+
+  ASSERT (vec_len (node->next_nodes) == node_runtime->n_next_nodes);
+
+  next_frame = vlib_node_runtime_get_next_frame (vm, node_runtime, next_index);
+  next_node = vec_elt (nm->nodes, node->next_nodes[next_index]);
+
+  if (next_node->owner_node_index != VLIB_INVALID_NODE_INDEX)
+    {
+      /* Get frame from previous owner. */
+      vlib_next_frame_t * owner_next_frame;
+      vlib_next_frame_t tmp;
+
+      owner_next_frame =
+	vlib_node_get_next_frame (vm,
+				  next_node->owner_node_index,
+				  next_node->owner_next_index);
+
+      /* Swap target next frame with owner's. */
+      tmp = owner_next_frame[0];
+      owner_next_frame[0] = next_frame[0];
+      next_frame[0] = tmp;
+
+      /*
+       * If next_frame is already pending, we have to track down
+       * all pending frames and fix their next_frame_index fields.
+       */
+      if (next_frame->flags & VLIB_FRAME_PENDING)
+        {
+          vlib_pending_frame_t * p;
+          if (next_frame->frame_index != ~0)
+            {
+              vec_foreach (p, nm->pending_frames)
+                {
+                  if (p->frame_index == next_frame->frame_index)
+                    {
+                      p->next_frame_index = 
+                        next_frame - vm->node_main.next_frames;
+                    }
+                }
+            }
+        }
+    }
+  else
+    {
+      /* No previous owner. Take ownership. */
+      next_frame->flags |= VLIB_FRAME_OWNER;
+    }
+					   
+  /* Record new owner. */
+  next_node->owner_node_index = node->index;
+  next_node->owner_next_index = next_index;
+
+  /* Now we should be owner. */
+  ASSERT (next_frame->flags & VLIB_FRAME_OWNER);
+}	      
+
+/* Make sure that magic number is still there.
+   Otherwise, it is likely that caller has overrun frame arguments. */
+always_inline void
+validate_frame_magic (vlib_main_t * vm,
+		      vlib_frame_t * f,
+		      vlib_node_t * n,
+		      uword next_index)
+{
+  vlib_node_t * next_node = vlib_get_node (vm, n->next_nodes[next_index]);
+  u32 * magic = vlib_frame_find_magic (f, next_node);
+  ASSERT (VLIB_FRAME_MAGIC == magic[0]);
+}
+
+vlib_frame_t *
+vlib_get_next_frame_internal (vlib_main_t * vm,
+			      vlib_node_runtime_t * node,
+			      u32 next_index,
+			      u32 allocate_new_next_frame)
+{
+  vlib_frame_t * f;
+  vlib_next_frame_t * nf;
+  u32 n_used;
+
+  nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
+
+  /* Make sure this next frame owns right to enqueue to destination frame. */
+  if (PREDICT_FALSE (! (nf->flags & VLIB_FRAME_OWNER)))
+    vlib_next_frame_change_ownership (vm, node, next_index);
+
+  /* ??? Don't need valid flag: can use frame_index == ~0 */
+  if (PREDICT_FALSE (! (nf->flags & VLIB_FRAME_IS_ALLOCATED)))
+    {
+      nf->frame_index = vlib_frame_alloc (vm, node, next_index);
+      nf->flags |= VLIB_FRAME_IS_ALLOCATED;
+    }
+
+  f = vlib_get_frame (vm, nf->frame_index);
+
+  /* Has frame been removed from pending vector (e.g. finished dispatching)?
+     If so we can reuse frame. */
+  if ((nf->flags & VLIB_FRAME_PENDING) && ! (f->flags & VLIB_FRAME_PENDING))
+    {
+      nf->flags &= ~VLIB_FRAME_PENDING;
+      f->n_vectors = 0;
+    }
+
+  /* Allocate new frame if current one is already full. */
+  n_used = f->n_vectors;
+  if (n_used >= VLIB_FRAME_SIZE || (allocate_new_next_frame && n_used > 0))
+    {
+      /* Old frame may need to be freed after dispatch, since we'll have
+	 two redundant frames from node -> next node. */
+      if (! (nf->flags & VLIB_FRAME_NO_FREE_AFTER_DISPATCH))
+	{
+	  vlib_frame_t * f_old = vlib_get_frame (vm, nf->frame_index);
+	  f_old->flags |= VLIB_FRAME_FREE_AFTER_DISPATCH;
+	}
+
+      /* Allocate new frame to replace full one. */
+      nf->frame_index = vlib_frame_alloc (vm, node, next_index);
+      f = vlib_get_frame (vm, nf->frame_index);
+      n_used = f->n_vectors;
+    }
+
+  /* Should have free vectors in frame now. */
+  ASSERT (n_used < VLIB_FRAME_SIZE);
+
+  if (CLIB_DEBUG > 0)
+    {
+      validate_frame_magic (vm, f,
+			    vlib_get_node (vm, node->node_index),
+			    next_index);
+    }
+
+  return f;
+}
+
+static void
+vlib_put_next_frame_validate (vlib_main_t * vm,
+			      vlib_node_runtime_t * rt,
+			      u32 next_index,
+			      u32 n_vectors_left)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_next_frame_t * nf;
+  vlib_frame_t * f;
+  vlib_node_runtime_t * next_rt;
+  vlib_node_t * next_node;
+  u32 n_before, n_after;
+
+  nf = vlib_node_runtime_get_next_frame (vm, rt, next_index);
+  f = vlib_get_frame (vm, nf->frame_index);
+
+  ASSERT (n_vectors_left <= VLIB_FRAME_SIZE);
+  n_after = VLIB_FRAME_SIZE - n_vectors_left;
+  n_before = f->n_vectors;
+
+  ASSERT (n_after >= n_before);
+
+  next_rt = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INTERNAL],
+			      nf->node_runtime_index);
+  next_node = vlib_get_node (vm, next_rt->node_index);
+  if (n_after > 0 && next_node->validate_frame)
+    {
+      u8 * msg = next_node->validate_frame (vm, rt, f);
+      if (msg)
+	{
+	  clib_warning ("%v", msg);
+	  ASSERT (0);
+	}
+      vec_free (msg);
+    }
+}
+
+void
+vlib_put_next_frame (vlib_main_t * vm,
+		     vlib_node_runtime_t * r,
+		     u32 next_index,
+		     u32 n_vectors_left)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_next_frame_t * nf;
+  vlib_frame_t * f;
+  u32 n_vectors_in_frame;
+
+  if (DPDK == 0 && CLIB_DEBUG > 0)
+    vlib_put_next_frame_validate (vm, r, next_index, n_vectors_left);
+
+  nf = vlib_node_runtime_get_next_frame (vm, r, next_index);
+  f = vlib_get_frame (vm, nf->frame_index);
+
+  /* Make sure that magic number is still there.  Otherwise, caller
+     has overrun frame meta data. */
+  if (CLIB_DEBUG > 0)
+    {
+      vlib_node_t * node = vlib_get_node (vm, r->node_index);
+      validate_frame_magic (vm, f, node, next_index);
+    }
+
+  /* Convert # of vectors left -> number of vectors there. */
+  ASSERT (n_vectors_left <= VLIB_FRAME_SIZE);
+  n_vectors_in_frame = VLIB_FRAME_SIZE - n_vectors_left;
+
+  f->n_vectors = n_vectors_in_frame;
+
+  /* If vectors were added to frame, add to pending vector. */
+  if (PREDICT_TRUE (n_vectors_in_frame > 0))
+    {
+      vlib_pending_frame_t * p;
+      u32 v0, v1;
+      
+      r->cached_next_index = next_index;
+
+      if (!(f->flags & VLIB_FRAME_PENDING))
+        {
+          __attribute__((unused)) vlib_node_t *node;
+          vlib_node_t *next_node;
+          vlib_node_runtime_t *next_runtime;
+
+          node = vlib_get_node (vm, r->node_index);
+          next_node = vlib_get_next_node (vm, r->node_index, next_index);
+          next_runtime = vlib_node_get_runtime (vm, next_node->index);
+
+          vec_add2 (nm->pending_frames, p, 1);
+
+          p->frame_index = nf->frame_index;
+          p->node_runtime_index = nf->node_runtime_index;
+          p->next_frame_index = nf - nm->next_frames;
+          nf->flags |= VLIB_FRAME_PENDING;
+          f->flags |= VLIB_FRAME_PENDING;
+
+          /* 
+           * If we're going to dispatch this frame on another thread,
+           * force allocation of a new frame. Otherwise, we create
+           * a dangling frame reference. Each thread has its own copy of
+           * the next_frames vector.
+           */
+          if (0 && r->cpu_index != next_runtime->cpu_index)
+            {
+              nf->frame_index = ~0;
+              nf->flags &= ~(VLIB_FRAME_PENDING | VLIB_FRAME_IS_ALLOCATED);
+            }
+        }
+
+      /* Copy trace flag from next_frame and from runtime. */
+      nf->flags |= (nf->flags & VLIB_NODE_FLAG_TRACE) | (r->flags & VLIB_NODE_FLAG_TRACE);
+
+      v0 = nf->vectors_since_last_overflow;
+      v1 = v0 + n_vectors_in_frame;
+      nf->vectors_since_last_overflow = v1;
+      if (PREDICT_FALSE (v1 < v0))
+	{
+	  vlib_node_t * node = vlib_get_node (vm, r->node_index);
+	  vec_elt (node->n_vectors_by_next_node, next_index) += v0;
+	}
+    }
+}
+
+/* Sync up runtime (32 bit counters) and main node stats (64 bit counters). */
+never_inline void
+vlib_node_runtime_sync_stats (vlib_main_t * vm,
+			      vlib_node_runtime_t * r,
+			      uword n_calls,
+			      uword n_vectors,
+			      uword n_clocks)
+{
+  vlib_node_t * n = vlib_get_node (vm, r->node_index);
+
+  n->stats_total.calls += n_calls + r->calls_since_last_overflow;
+  n->stats_total.vectors += n_vectors + r->vectors_since_last_overflow;
+  n->stats_total.clocks += n_clocks + r->clocks_since_last_overflow;
+  n->stats_total.max_clock = r->max_clock;
+  n->stats_total.max_clock_n = r->max_clock_n;
+
+  r->calls_since_last_overflow = 0;
+  r->vectors_since_last_overflow = 0;
+  r->clocks_since_last_overflow = 0;
+}
+
+always_inline void
+vlib_process_sync_stats (vlib_main_t * vm,
+			 vlib_process_t * p,
+			 uword n_calls,
+			 uword n_vectors,
+			 uword n_clocks)
+{
+  vlib_node_runtime_t * rt = &p->node_runtime;
+  vlib_node_t * n = vlib_get_node (vm, rt->node_index);
+  vlib_node_runtime_sync_stats (vm, rt, n_calls, n_vectors, n_clocks);
+  n->stats_total.suspends += p->n_suspends;
+  p->n_suspends = 0;
+}
+
+void vlib_node_sync_stats (vlib_main_t * vm, vlib_node_t * n)
+{
+  vlib_node_runtime_t * rt;
+
+  if (n->type == VLIB_NODE_TYPE_PROCESS)
+    {
+      /* Nothing to do for PROCESS nodes except in main thread */
+      if (vm != &vlib_global_main) return;
+
+      vlib_process_t * p = vlib_get_process_from_node (vm, n);
+      n->stats_total.suspends += p->n_suspends;
+      p->n_suspends = 0;
+      rt = &p->node_runtime;
+    }
+  else
+    rt = vec_elt_at_index (vm->node_main.nodes_by_type[n->type], n->runtime_index);
+
+  vlib_node_runtime_sync_stats (vm, rt, 0, 0, 0);
+
+  /* Sync up runtime next frame vector counters with main node structure. */
+  {
+    vlib_next_frame_t * nf;
+    uword i;
+    for (i = 0; i < rt->n_next_nodes; i++)
+      {
+	nf = vlib_node_runtime_get_next_frame (vm, rt, i);
+	vec_elt (n->n_vectors_by_next_node, i) += nf->vectors_since_last_overflow;
+	nf->vectors_since_last_overflow = 0;
+      }
+  }
+}
+
+always_inline u32
+vlib_node_runtime_update_stats (vlib_main_t * vm,
+				vlib_node_runtime_t * node,
+				uword n_calls,
+				uword n_vectors,
+				uword n_clocks)
+{
+  u32 ca0, ca1, v0, v1, cl0, cl1, r;
+
+  cl0 = cl1 = node->clocks_since_last_overflow;
+  ca0 = ca1 = node->calls_since_last_overflow;
+  v0 = v1 = node->vectors_since_last_overflow;
+
+  ca1 = ca0 + n_calls;
+  v1 = v0 + n_vectors;
+  cl1 = cl0 + n_clocks;
+
+  node->calls_since_last_overflow = ca1;
+  node->clocks_since_last_overflow = cl1;
+  node->vectors_since_last_overflow = v1;
+  node->max_clock_n = node->max_clock > n_clocks ?
+                      node->max_clock_n : n_vectors;
+  node->max_clock = node->max_clock > n_clocks ?
+                    node->max_clock : n_clocks;
+
+  r = vlib_node_runtime_update_main_loop_vector_stats (vm, node, n_vectors);
+
+  if (PREDICT_FALSE (ca1 < ca0 || v1 < v0 || cl1 < cl0))
+    {
+      node->calls_since_last_overflow = ca0;
+      node->clocks_since_last_overflow = cl0;
+      node->vectors_since_last_overflow = v0;
+      vlib_node_runtime_sync_stats (vm, node, n_calls, n_vectors, n_clocks);
+    }
+
+  return r;
+}
+
+always_inline void
+vlib_process_update_stats (vlib_main_t * vm,
+			   vlib_process_t * p,
+			   uword n_calls,
+			   uword n_vectors,
+			   uword n_clocks)
+{
+  vlib_node_runtime_update_stats (vm, &p->node_runtime,
+				  n_calls, n_vectors, n_clocks);
+}
+
+static clib_error_t *
+vlib_cli_elog_clear (vlib_main_t * vm,
+		     unformat_input_t * input,
+		     vlib_cli_command_t * cmd)
+{
+  elog_reset_buffer (&vm->elog_main);
+  return 0;
+}
+
+VLIB_CLI_COMMAND (elog_clear_cli, static) = {
+  .path = "clear event-logger",
+  .short_help = "Clear current event log",
+  .function = vlib_cli_elog_clear,
+};
+
+#ifdef CLIB_UNIX
+static clib_error_t *
+elog_save_buffer (vlib_main_t * vm,
+		  unformat_input_t * input,
+		  vlib_cli_command_t * cmd)
+{
+  elog_main_t * em = &vm->elog_main;
+  char * file, * chroot_file;
+  clib_error_t * error = 0;
+
+  if (! unformat (input, "%s", &file))
+    {
+      vlib_cli_output (vm, "expected file name, got `%U'",
+		       format_unformat_error, input);
+      return 0;
+    }
+
+  /* It's fairly hard to get "../oopsie" through unformat; just in case */
+  if (strstr(file, "..") || index(file, '/'))
+    {
+      vlib_cli_output (vm, "illegal characters in filename '%s'", file);
+      return 0;
+    }
+
+  chroot_file = (char *) format (0, "/tmp/%s%c", file, 0);
+
+  vec_free(file);
+
+  vlib_cli_output (vm, "Saving %wd of %wd events to %s",
+                   elog_n_events_in_buffer (em),
+                   elog_buffer_capacity (em),
+                   chroot_file);
+  
+  vlib_worker_thread_barrier_sync (vm);
+  error =  elog_write_file (em, chroot_file);
+  vlib_worker_thread_barrier_release(vm);
+  vec_free (chroot_file);
+  return error;
+}
+
+VLIB_CLI_COMMAND (elog_save_cli, static) = {
+  .path = "save event-logger",
+  .short_help = "save event-logger <filename> (saves log in /tmp/<filename>)",
+  .function = elog_save_buffer,
+};
+
+#endif /* CLIB_UNIX */
+
+static void elog_show_buffer_internal (vlib_main_t * vm, u32 n_events_to_show)
+{
+  elog_main_t * em = &vm->elog_main;
+  elog_event_t * e, * es;
+  f64 dt;
+
+  /* Show events in VLIB time since log clock starts after VLIB clock. */
+  dt = (em->init_time.cpu - vm->clib_time.init_cpu_time) 
+    * vm->clib_time.seconds_per_clock;
+
+  es = elog_peek_events (em);
+  vlib_cli_output (vm, "%d events in buffer", vec_len (es));
+  vec_foreach (e, es)
+    {
+      vlib_cli_output (vm, "%18.9f: %U",
+		       e->time + dt,
+		       format_elog_event, em, e);
+      n_events_to_show--;
+      if (n_events_to_show == 0)
+	break;
+    }
+  vec_free (es);
+  
+}
+
+static clib_error_t *
+elog_show_buffer (vlib_main_t * vm,
+		  unformat_input_t * input,
+		  vlib_cli_command_t * cmd)
+{
+  u32 n_events_to_show;
+  clib_error_t * error = 0;
+
+  n_events_to_show = 250;
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "%d", &n_events_to_show))
+	;
+      else if (unformat (input, "all"))
+	n_events_to_show = ~0;
+      else
+	return unformat_parse_error (input);
+    }
+  elog_show_buffer_internal (vm, n_events_to_show);
+  return error;
+}
+
+VLIB_CLI_COMMAND (elog_show_cli, static) = {
+  .path = "show event-logger",
+  .short_help = "Show event logger info",
+  .function = elog_show_buffer,
+};
+
+void vlib_gdb_show_event_log (void)
+{
+  elog_show_buffer_internal (vlib_get_main(), (u32)~0);
+}
+
+always_inline void
+vlib_elog_main_loop_event (vlib_main_t * vm,
+			   u32 node_index,
+			   u64 time,
+			   u32 n_vectors,
+			   u32 is_return)
+{
+  elog_main_t * em = &vm->elog_main;
+
+  if (VLIB_ELOG_MAIN_LOOP)
+    elog (em,
+	  /* event type */
+	  vec_elt_at_index (is_return
+			    ? vm->node_return_elog_event_types
+			    : vm->node_call_elog_event_types,
+			    node_index),
+	  /* data to log */ n_vectors);
+}
+
+void vlib_dump_context_trace (vlib_main_t *vm, u32 bi)
+{
+  vlib_node_main_t * vnm = &vm->node_main;
+  vlib_buffer_t * b;
+  u8 i, n;
+
+  if (VLIB_BUFFER_TRACE_TRAJECTORY)
+    {
+      b = vlib_get_buffer (vm, bi);
+      n = b->pre_data[0];
+
+      fformat(stderr, "Context trace for bi %d b 0x%llx, visited %d\n",
+              bi, b, n);
+
+      if (n == 0 || n > 20)
+        {
+          fformat(stderr, "n is unreasonable\n");
+          return;
+        }
+
+
+      for (i = 0; i < n; i++)
+        {
+          u32 node_index;
+
+          node_index = b->pre_data[i+1];
+
+          if (node_index > vec_len (vnm->nodes))
+            {
+              fformat(stderr, "Skip bogus node index %d\n", node_index);
+              continue;
+            }
+      
+          fformat(stderr, "%v (%d)\n", vnm->nodes[node_index]->name, 
+                  node_index);
+        }
+    }
+  else
+    {
+      fformat(stderr, 
+              "in vlib/buffers.h, #define VLIB_BUFFER_TRACE_TRAJECTORY 1\n");
+    }
+}
+
+
+/* static_always_inline */ u64
+dispatch_node (vlib_main_t * vm,
+	       vlib_node_runtime_t * node,
+	       vlib_node_type_t type,
+	       vlib_node_state_t dispatch_state,
+	       vlib_frame_t * frame,
+	       u64 last_time_stamp)
+{
+  uword n, v;
+  u64 t;
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_next_frame_t * nf;
+
+  if (CLIB_DEBUG > 0)
+    {
+      vlib_node_t * n = vlib_get_node (vm, node->node_index);
+      ASSERT (n->type == type);
+    }
+
+  /* Only non-internal nodes may be disabled. */
+  if (type != VLIB_NODE_TYPE_INTERNAL && node->state != dispatch_state)
+    {
+      ASSERT (type != VLIB_NODE_TYPE_INTERNAL);
+      return last_time_stamp;
+    }
+
+  if ((type == VLIB_NODE_TYPE_PRE_INPUT || type == VLIB_NODE_TYPE_INPUT)
+      && dispatch_state != VLIB_NODE_STATE_INTERRUPT)
+    {
+      u32 c = node->input_main_loops_per_call;
+      /* Only call node when count reaches zero. */
+      if (c)
+	{
+	  node->input_main_loops_per_call = c - 1;
+	  return last_time_stamp;
+	}
+    }
+
+  /* Speculatively prefetch next frames. */
+  if (node->n_next_nodes > 0)
+    {
+      nf = vec_elt_at_index (nm->next_frames, node->next_frame_index);
+      CLIB_PREFETCH (nf, 4 * sizeof (nf[0]), WRITE);
+    }
+
+  vm->cpu_time_last_node_dispatch = last_time_stamp;
+
+  if (1  /* || vm->cpu_index == node->cpu_index */)
+    {
+      vlib_main_t *stat_vm;
+
+      stat_vm = /* vlib_mains ? vlib_mains[0] : */ vm;
+
+      vlib_elog_main_loop_event (vm, node->node_index,
+                                 last_time_stamp,
+                                 frame ? frame->n_vectors : 0,
+                                 /* is_after */ 0);
+      
+      /*
+       * Turn this on if you run into
+       * "bad monkey" contexts, and you want to know exactly
+       * which nodes they've visited... See ixge.c...
+       */
+      if (VLIB_BUFFER_TRACE_TRAJECTORY && frame)
+        {
+          int i;
+          int log_index;
+          u32 * from;
+          from = vlib_frame_vector_args (frame);
+          for (i = 0; i < frame->n_vectors; i++)
+            {
+              vlib_buffer_t *b = vlib_get_buffer (vm, from[i]);
+              ASSERT (b->pre_data[0] < 32);
+              log_index = b->pre_data[0]++ + 1;
+              b->pre_data[log_index] = node->node_index;
+            }
+          n = node->function (vm, node, frame);
+        }
+      else
+          n = node->function (vm, node, frame);
+
+      t = clib_cpu_time_now ();
+
+      vlib_elog_main_loop_event (vm, node->node_index, t, n, /* is_after */ 1);
+
+      vm->main_loop_vectors_processed += n;
+      vm->main_loop_nodes_processed += n > 0;
+
+      v = vlib_node_runtime_update_stats (stat_vm, node,
+                                          /* n_calls */ 1,
+                                          /* n_vectors */ n,
+                                          /* n_clocks */ t - last_time_stamp);
+
+      /* When in interrupt mode and vector rate crosses threshold switch to
+         polling mode. */
+      if ((DPDK == 0 && dispatch_state == VLIB_NODE_STATE_INTERRUPT)
+          || (DPDK == 0 && dispatch_state == VLIB_NODE_STATE_POLLING
+              && (node->flags 
+                  & VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE)))
+        {
+          ELOG_TYPE_DECLARE (e) = {
+            .function = (char *) __FUNCTION__,
+            .format = "%s vector length %d, switching to %s",
+            .format_args = "T4i4t4",
+            .n_enum_strings = 2,
+            .enum_strings = {
+              "interrupt", "polling",
+            },
+          };
+          struct { u32 node_name, vector_length, is_polling; } * ed;
+          
+          if (dispatch_state == VLIB_NODE_STATE_INTERRUPT
+              && v >= nm->polling_threshold_vector_length)
+            {
+              vlib_node_t * n = vlib_get_node (vm, node->node_index);
+              n->state = VLIB_NODE_STATE_POLLING;
+              node->state = VLIB_NODE_STATE_POLLING;
+              ASSERT (! (node->flags & VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE));
+              node->flags &= ~VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE;
+              node->flags |= VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE;
+              nm->input_node_counts_by_state[VLIB_NODE_STATE_INTERRUPT] -= 1;
+              nm->input_node_counts_by_state[VLIB_NODE_STATE_POLLING] += 1;
+
+              ed = ELOG_DATA (&vm->elog_main, e);
+              ed->node_name = n->name_elog_string;
+              ed->vector_length = v;
+              ed->is_polling = 1;
+            }
+          else if (dispatch_state == VLIB_NODE_STATE_POLLING
+                   && v <= nm->interrupt_threshold_vector_length)
+            {
+              vlib_node_t * n = vlib_get_node (vm, node->node_index);
+              if (node->flags & VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE)
+                {
+                  /* Switch to interrupt mode after dispatch in polling one more time.
+                     This allows driver to re-enable interrupts. */
+                  n->state = VLIB_NODE_STATE_INTERRUPT;
+                  node->state = VLIB_NODE_STATE_INTERRUPT;
+                  node->flags &= ~VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE;
+                  nm->input_node_counts_by_state[VLIB_NODE_STATE_POLLING] -= 1;
+                  nm->input_node_counts_by_state[VLIB_NODE_STATE_INTERRUPT] += 1;
+
+                }
+              else
+                {
+                  node->flags |= VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE;
+                  ed = ELOG_DATA (&vm->elog_main, e);
+                  ed->node_name = n->name_elog_string;
+                  ed->vector_length = v;
+                  ed->is_polling = 0;
+                }
+            }
+        }
+    }
+
+  return t;
+}
+
+/* static */ u64
+dispatch_pending_node (vlib_main_t * vm,
+		       vlib_pending_frame_t * p,
+		       u64 last_time_stamp)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_frame_t * f;
+  vlib_next_frame_t * nf, nf_dummy;
+  vlib_node_runtime_t * n;
+  u32 restore_frame_index;
+
+  n = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INTERNAL],
+			p->node_runtime_index);
+
+  f = vlib_get_frame (vm, p->frame_index);
+  if (p->next_frame_index == VLIB_PENDING_FRAME_NO_NEXT_FRAME)
+    {
+      /* No next frame: so use dummy on stack. */
+      nf = &nf_dummy;
+      nf->flags = f->flags & VLIB_NODE_FLAG_TRACE;
+      nf->frame_index = ~p->frame_index;
+    }
+  else
+    nf = vec_elt_at_index (nm->next_frames, p->next_frame_index);
+
+  ASSERT (f->flags & VLIB_FRAME_IS_ALLOCATED);
+
+  /* Force allocation of new frame while current frame is being
+     dispatched. */
+  restore_frame_index = ~0;
+  if (nf->frame_index == p->frame_index)
+    {
+      nf->frame_index = ~0;
+      nf->flags &= ~VLIB_FRAME_IS_ALLOCATED;
+      if (! (n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH))
+	restore_frame_index = p->frame_index;
+    }
+
+  /* Frame must be pending. */
+  ASSERT (f->flags & VLIB_FRAME_PENDING);
+  ASSERT (f->n_vectors > 0);
+
+  /* Copy trace flag from next frame to node.
+     Trace flag indicates that at least one vector in the dispatched
+     frame is traced. */
+  n->flags &= ~VLIB_NODE_FLAG_TRACE;
+  n->flags |= (nf->flags & VLIB_FRAME_TRACE) ? VLIB_NODE_FLAG_TRACE : 0;
+  nf->flags &= ~VLIB_FRAME_TRACE;
+
+  last_time_stamp = dispatch_node (vm, n,
+				   VLIB_NODE_TYPE_INTERNAL,
+				   VLIB_NODE_STATE_POLLING,
+				   f, last_time_stamp);
+
+  f->flags &= ~VLIB_FRAME_PENDING;
+
+  /* Frame is ready to be used again, so restore it. */
+  if (restore_frame_index != ~0)
+    {
+      /* p->next_frame_index can change during node dispatch if node
+	 function decides to change graph hook up. */
+      nf = vec_elt_at_index (nm->next_frames, p->next_frame_index);
+      nf->frame_index = restore_frame_index;
+      nf->flags |= VLIB_FRAME_IS_ALLOCATED;
+    }
+
+  if (f->flags & VLIB_FRAME_FREE_AFTER_DISPATCH)
+    {
+      ASSERT (! (n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH));
+      vlib_frame_free (vm, n, f);
+    }
+
+  return last_time_stamp;
+}
+
+always_inline uword
+vlib_process_stack_is_valid (vlib_process_t * p)
+{ return p->stack[0] == VLIB_PROCESS_STACK_MAGIC; }
+
+typedef struct {
+  vlib_main_t * vm;
+  vlib_process_t * process;
+  vlib_frame_t * frame;
+} vlib_process_bootstrap_args_t;
+
+/* Called in process stack. */
+static uword vlib_process_bootstrap (uword _a)
+{
+  vlib_process_bootstrap_args_t * a;
+  vlib_main_t * vm;
+  vlib_node_runtime_t * node;
+  vlib_frame_t * f;
+  vlib_process_t * p;
+  uword n;
+
+  a = uword_to_pointer (_a, vlib_process_bootstrap_args_t *);
+
+  vm = a->vm;
+  p = a->process;
+  f = a->frame;
+  node = &p->node_runtime;
+
+  n = node->function (vm, node, f);
+
+  ASSERT (vlib_process_stack_is_valid (p));
+
+  clib_longjmp (&p->return_longjmp, n);
+
+  return n;
+}
+
+/* Called in main stack. */
+static_always_inline uword
+vlib_process_startup (vlib_main_t * vm,
+		      vlib_process_t * p,
+		      vlib_frame_t * f)
+{
+  vlib_process_bootstrap_args_t a;
+  uword r;
+
+  a.vm = vm;
+  a.process = p;
+  a.frame = f;
+
+  r = clib_setjmp (&p->return_longjmp, VLIB_PROCESS_RETURN_LONGJMP_RETURN);
+  if (r == VLIB_PROCESS_RETURN_LONGJMP_RETURN)
+    r = clib_calljmp (vlib_process_bootstrap, pointer_to_uword (&a),
+		      (void *) p->stack + (1 << p->log2_n_stack_bytes));
+
+  return r;
+}
+
+static_always_inline uword
+vlib_process_resume (vlib_process_t * p)
+{
+  uword r;
+  p->flags &= ~(VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
+		| VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT
+		| VLIB_PROCESS_RESUME_PENDING);
+  r = clib_setjmp (&p->return_longjmp, VLIB_PROCESS_RETURN_LONGJMP_RETURN);
+  if (r == VLIB_PROCESS_RETURN_LONGJMP_RETURN)
+    clib_longjmp (&p->resume_longjmp, VLIB_PROCESS_RESUME_LONGJMP_RESUME);
+  return r;
+}
+
+static u64
+dispatch_process (vlib_main_t * vm,
+		  vlib_process_t * p,
+		  vlib_frame_t * f,
+		  u64 last_time_stamp)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_node_runtime_t * node_runtime = &p->node_runtime;
+  vlib_node_t * node = vlib_get_node (vm, node_runtime->node_index);
+  u64 t;
+  uword n_vectors, is_suspend;
+
+  if (node->state != VLIB_NODE_STATE_POLLING
+      || (p->flags & (VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
+		      | VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT)))
+    return last_time_stamp;
+
+  p->flags |= VLIB_PROCESS_IS_RUNNING;
+
+  t = last_time_stamp;
+  vlib_elog_main_loop_event (vm, node_runtime->node_index, t,
+			     f ? f->n_vectors : 0, /* is_after */ 0);
+
+  /* Save away current process for suspend. */
+  nm->current_process_index = node->runtime_index;
+
+  n_vectors = vlib_process_startup (vm, p, f);
+
+  nm->current_process_index = ~0;
+
+  ASSERT (n_vectors != VLIB_PROCESS_RETURN_LONGJMP_RETURN);
+  is_suspend = n_vectors == VLIB_PROCESS_RETURN_LONGJMP_SUSPEND;
+  if (is_suspend)
+    {
+      vlib_pending_frame_t * pf;
+
+      n_vectors = 0;
+      pool_get (nm->suspended_process_frames, pf);
+      pf->node_runtime_index = node->runtime_index;
+      pf->frame_index = f ? vlib_frame_index (vm, f) : ~0;
+      pf->next_frame_index = ~0;
+
+      p->n_suspends += 1;
+      p->suspended_process_frame_index = pf - nm->suspended_process_frames;
+
+      if (p->flags & VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK)
+	timing_wheel_insert (&nm->timing_wheel, p->resume_cpu_time,
+			     vlib_timing_wheel_data_set_suspended_process (node->runtime_index));
+    }
+  else
+    p->flags &= ~VLIB_PROCESS_IS_RUNNING;
+
+  t = clib_cpu_time_now ();
+
+  vlib_elog_main_loop_event (vm, node_runtime->node_index, t, is_suspend, /* is_after */ 1);
+
+  vlib_process_update_stats (vm, p,
+			     /* n_calls */ ! is_suspend,
+			     /* n_vectors */ n_vectors,
+			     /* n_clocks */ t - last_time_stamp);
+
+  return t;
+}
+
+void vlib_start_process (vlib_main_t * vm, uword process_index)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_process_t * p = vec_elt (nm->processes, process_index);
+  dispatch_process (vm, p, /* frame */ 0, /* cpu_time_now */ 0);
+}
+
+static u64
+dispatch_suspended_process (vlib_main_t * vm,
+			    uword process_index,
+			    u64 last_time_stamp)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  vlib_node_runtime_t * node_runtime;
+  vlib_node_t * node;
+  vlib_frame_t * f;
+  vlib_process_t * p;
+  vlib_pending_frame_t * pf;
+  u64 t, n_vectors, is_suspend;
+  
+  t = last_time_stamp;
+
+  p = vec_elt (nm->processes, process_index);
+  if (PREDICT_FALSE (! (p->flags & VLIB_PROCESS_IS_RUNNING)))
+    return last_time_stamp;
+
+  ASSERT (p->flags & (VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK
+		      | VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_EVENT));
+
+  pf = pool_elt_at_index (nm->suspended_process_frames, p->suspended_process_frame_index);
+
+  node_runtime = &p->node_runtime;
+  node = vlib_get_node (vm, node_runtime->node_index);
+  f = pf->frame_index != ~0 ? vlib_get_frame (vm, pf->frame_index) : 0;
+
+  vlib_elog_main_loop_event (vm, node_runtime->node_index, t, f ? f->n_vectors : 0, /* is_after */ 0);
+
+  /* Save away current process for suspend. */
+  nm->current_process_index = node->runtime_index;
+
+  n_vectors = vlib_process_resume (p);
+  t = clib_cpu_time_now ();
+
+  nm->current_process_index = ~0;
+
+  is_suspend = n_vectors == VLIB_PROCESS_RETURN_LONGJMP_SUSPEND;
+  if (is_suspend)
+    {
+      /* Suspend it again. */
+      n_vectors = 0;
+      p->n_suspends += 1;
+      if (p->flags & VLIB_PROCESS_IS_SUSPENDED_WAITING_FOR_CLOCK)
+	timing_wheel_insert (&nm->timing_wheel, p->resume_cpu_time,
+			     vlib_timing_wheel_data_set_suspended_process (node->runtime_index));
+    }
+  else
+    {
+      p->flags &= ~VLIB_PROCESS_IS_RUNNING;
+      p->suspended_process_frame_index = ~0;
+      pool_put (nm->suspended_process_frames, pf);
+    }
+
+  t = clib_cpu_time_now ();
+  vlib_elog_main_loop_event (vm, node_runtime->node_index, t, ! is_suspend, /* is_after */ 1);
+
+  vlib_process_update_stats (vm, p,
+			     /* n_calls */ ! is_suspend,
+			     /* n_vectors */ n_vectors,
+			     /* n_clocks */ t - last_time_stamp);
+
+  return t;
+}
+
+static void vlib_main_loop (vlib_main_t * vm)
+{
+  vlib_node_main_t * nm = &vm->node_main;
+  uword i;
+  u64 cpu_time_now;
+
+  /* Initialize pending node vector. */
+  vec_resize (nm->pending_frames, 32);
+  _vec_len (nm->pending_frames) = 0;
+
+  /* Mark time of main loop start. */
+  cpu_time_now = vm->clib_time.last_cpu_time;
+  vm->cpu_time_main_loop_start = cpu_time_now;
+
+  /* Arrange for first level of timing wheel to cover times we care
+     most about. */
+  nm->timing_wheel.min_sched_time = 10e-6;
+  nm->timing_wheel.max_sched_time = 10e-3;
+  timing_wheel_init (&nm->timing_wheel,
+		     cpu_time_now,
+		     vm->clib_time.clocks_per_second);
+
+  /* Pre-allocate expired nodes. */
+  vec_alloc (nm->data_from_advancing_timing_wheel, 32);
+  vec_alloc (nm->pending_interrupt_node_runtime_indices, 32);
+
+  if (! nm->polling_threshold_vector_length)
+    nm->polling_threshold_vector_length = 10;
+  if (! nm->interrupt_threshold_vector_length)
+    nm->interrupt_threshold_vector_length = 5;
+
+  nm->current_process_index = ~0;
+
+  /* Start all processes. */
+  {
+    uword i;
+    for (i = 0; i < vec_len (nm->processes); i++)
+      cpu_time_now = dispatch_process (vm, nm->processes[i], /* frame */ 0, cpu_time_now);
+  }
+
+  while (1)
+    {
+      vlib_node_runtime_t * n;
+
+      /* Process pre-input nodes. */
+      vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_PRE_INPUT])
+	cpu_time_now = dispatch_node (vm, n,
+				      VLIB_NODE_TYPE_PRE_INPUT,
+				      VLIB_NODE_STATE_POLLING,
+				      /* frame */ 0,
+				      cpu_time_now);
+
+      /* Next process input nodes. */
+      vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_INPUT])
+	cpu_time_now = dispatch_node (vm, n,
+				      VLIB_NODE_TYPE_INPUT,
+				      VLIB_NODE_STATE_POLLING,
+				      /* frame */ 0,
+				      cpu_time_now);
+
+      if (PREDICT_FALSE(vm->queue_signal_pending))
+          if (vm->queue_signal_callback)
+              vm->queue_signal_callback (vm);
+
+      /* Next handle interrupts. */
+      {
+	uword l = _vec_len (nm->pending_interrupt_node_runtime_indices);
+	uword i;
+	if (l > 0)
+	  {
+	    _vec_len (nm->pending_interrupt_node_runtime_indices) = 0;
+	    for (i = 0; i < l; i++)
+	      {
+		n = vec_elt_at_index (nm->nodes_by_type[VLIB_NODE_TYPE_INPUT],
+				      nm->pending_interrupt_node_runtime_indices[i]);
+		cpu_time_now = dispatch_node (vm, n,
+					      VLIB_NODE_TYPE_INPUT,
+					      VLIB_NODE_STATE_INTERRUPT,
+					      /* frame */ 0,
+					      cpu_time_now);
+	      }
+	  }
+      }
+
+      /* Check if process nodes have expired from timing wheel. */
+      nm->data_from_advancing_timing_wheel
+	= timing_wheel_advance (&nm->timing_wheel, cpu_time_now,
+				nm->data_from_advancing_timing_wheel,
+				&nm->cpu_time_next_process_ready);
+
+      ASSERT (nm->data_from_advancing_timing_wheel != 0);
+      if (PREDICT_FALSE (_vec_len (nm->data_from_advancing_timing_wheel) > 0))
+	{
+	  uword i;
+
+	processes_timing_wheel_data:
+	  for (i = 0; i < _vec_len (nm->data_from_advancing_timing_wheel); i++)
+	    {
+	      u32 d = nm->data_from_advancing_timing_wheel[i];
+	      u32 di = vlib_timing_wheel_data_get_index (d);
+
+	      if (vlib_timing_wheel_data_is_timed_event (d))
+		{
+		  vlib_signal_timed_event_data_t * te = pool_elt_at_index (nm->signal_timed_event_data_pool, di);
+		  vlib_node_t * n = vlib_get_node (vm, te->process_node_index);
+		  vlib_process_t * p = vec_elt (nm->processes, n->runtime_index);
+		  void * data;
+		  data = vlib_process_signal_event_helper (nm, n, p, te->event_type_index, te->n_data_elts, te->n_data_elt_bytes);
+		  if (te->n_data_bytes < sizeof (te->inline_event_data))
+		    memcpy (data, te->inline_event_data, te->n_data_bytes);
+		  else
+		    {
+		      memcpy (data, te->event_data_as_vector, te->n_data_bytes);
+		      vec_free (te->event_data_as_vector);
+		    }
+		  pool_put (nm->signal_timed_event_data_pool, te);
+		}
+	      else
+		{
+		  cpu_time_now = clib_cpu_time_now();
+		  cpu_time_now = dispatch_suspended_process (vm, di, cpu_time_now);
+		}
+	    }
+
+	  /* Reset vector. */
+	  _vec_len (nm->data_from_advancing_timing_wheel) = 0;
+	}
+
+      /* Input nodes may have added work to the pending vector.
+         Process pending vector until there is nothing left.
+         All pending vectors will be processed from input -> output. */
+      for (i = 0; i < _vec_len (nm->pending_frames); i++)
+          cpu_time_now = dispatch_pending_node (vm, nm->pending_frames + i,
+                                                cpu_time_now);
+      /* Reset pending vector for next iteration. */
+      _vec_len (nm->pending_frames) = 0;
+      
+      /* Pending internal nodes may resume processes. */
+      if (_vec_len (nm->data_from_advancing_timing_wheel) > 0)
+	goto processes_timing_wheel_data;
+
+      vlib_increment_main_loop_counter (vm);
+
+      /* Record time stamp in case there are no enabled nodes and above
+	 calls do not update time stamp. */
+      cpu_time_now = clib_cpu_time_now ();
+    }
+}
+	       
+vlib_main_t vlib_global_main;
+
+static clib_error_t *
+vlib_main_configure (vlib_main_t * vm, unformat_input_t * input)
+{
+  int turn_on_mem_trace = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "memory-trace"))
+	turn_on_mem_trace = 1;
+
+      else if (unformat (input, "elog-events %d",
+			 &vm->elog_main.event_ring_size))
+	;
+      else
+	return unformat_parse_error (input);
+    }
+
+  unformat_free (input);
+
+  /* Enable memory trace as early as possible. */
+  if (turn_on_mem_trace)
+    clib_mem_trace (1);
+
+  return 0;
+}
+
+VLIB_EARLY_CONFIG_FUNCTION (vlib_main_configure, "vlib");
+
+/* Main function. */
+int vlib_main (vlib_main_t * vm, unformat_input_t * input)
+{
+  clib_error_t * error;
+
+  clib_time_init (&vm->clib_time);
+
+  /* Turn on event log. */
+  if (! vm->elog_main.event_ring_size)
+    vm->elog_main.event_ring_size = 128 << 10;
+  elog_init (&vm->elog_main, vm->elog_main.event_ring_size);
+  elog_enable_disable (&vm->elog_main, 1);
+
+  /* Default name. */
+  if (! vm->name)
+    vm->name = "VLIB";
+
+  vec_validate (vm->buffer_main, 0);
+
+  if ((error = vlib_thread_init (vm)))
+    {
+      clib_error_report (error);
+      goto done;
+    }
+
+  /* Register static nodes so that init functions may use them. */
+  vlib_register_all_static_nodes (vm);
+
+  /* Set seed for random number generator.
+     Allow user to specify seed to make random sequence deterministic. */
+  if (! unformat (input, "seed %wd", &vm->random_seed))
+    vm->random_seed = clib_cpu_time_now ();
+  clib_random_buffer_init (&vm->random_buffer, vm->random_seed);
+
+  /* See unix/main.c; most likely already set up */
+  if (vm->init_functions_called == 0)
+      vm->init_functions_called = hash_create (0, /* value bytes */ 0);
+  if ((error = vlib_call_all_init_functions (vm)))
+    goto done;
+
+  /* Initialize node graph. */
+  if ((error = vlib_node_main_init (vm)))
+    {
+      /* Arrange for graph hook up error to not be fatal when debugging. */
+      if (CLIB_DEBUG > 0)
+	clib_error_report (error);
+      else
+	goto done;
+    }
+
+  /* Create default buffer free list. */
+  vlib_buffer_get_or_create_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES,
+				       "default");
+
+  switch (clib_setjmp (&vm->main_loop_exit, VLIB_MAIN_LOOP_EXIT_NONE))
+    {
+    case VLIB_MAIN_LOOP_EXIT_NONE:
+      vm->main_loop_exit_set = 1;
+      break;
+
+    case VLIB_MAIN_LOOP_EXIT_CLI:
+      goto done;
+
+    default:
+      error = vm->main_loop_error;
+      goto done;
+    }
+
+  if ((error = vlib_call_all_config_functions (vm, input, 0 /* is_early */)))
+    goto done;
+
+  /* Call all main loop enter functions. */
+  {
+    clib_error_t * sub_error;
+    sub_error = vlib_call_all_main_loop_enter_functions (vm);
+    if (sub_error)
+      clib_error_report (sub_error);
+  }
+
+  vlib_main_loop (vm);
+
+ done:
+  /* Call all exit functions. */
+  {
+    clib_error_t * sub_error;
+    sub_error = vlib_call_all_main_loop_exit_functions (vm);
+    if (sub_error)
+      clib_error_report (sub_error);
+  }
+
+  if (error)
+    clib_error_report (error);
+
+  return 0;
+}