1 files changed, 455 insertions, 0 deletions

diff --git a/vpp/vppinfra/vppinfra/bihash_template.c b/vpp/vppinfra/vppinfra/bihash_template.c
new file mode 100644
index 00000000..4b0b4257
--- /dev/null
+++ b/vpp/vppinfra/vppinfra/bihash_template.c
@@ -0,0 +1,455 @@
+/*
+ * 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.
+ */
+
+/** @cond DOCUMENTATION_IS_IN_BIHASH_DOC_H */
+
+void BV (clib_bihash_init)
+  (BVT (clib_bihash) * h, char *name, u32 nbuckets, uword memory_size)
+{
+  void *oldheap;
+
+  nbuckets = 1 << (max_log2 (nbuckets));
+
+  h->name = (u8 *) name;
+  h->nbuckets = nbuckets;
+  h->log2_nbuckets = max_log2 (nbuckets);
+
+  h->mheap = mheap_alloc (0 /* use VM */ , memory_size);
+
+  oldheap = clib_mem_set_heap (h->mheap);
+  vec_validate_aligned (h->buckets, nbuckets - 1, CLIB_CACHE_LINE_BYTES);
+  h->writer_lock = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES,
+					   CLIB_CACHE_LINE_BYTES);
+
+  clib_mem_set_heap (oldheap);
+}
+
+void BV (clib_bihash_free) (BVT (clib_bihash) * h)
+{
+  mheap_free (h->mheap);
+  memset (h, 0, sizeof (*h));
+}
+
+static
+BVT (clib_bihash_value) *
+BV (value_alloc) (BVT (clib_bihash) * h, u32 log2_pages)
+{
+  BVT (clib_bihash_value) * rv = 0;
+  void *oldheap;
+
+  ASSERT (h->writer_lock[0]);
+  if (log2_pages >= vec_len (h->freelists) || h->freelists[log2_pages] == 0)
+    {
+      oldheap = clib_mem_set_heap (h->mheap);
+
+      vec_validate (h->freelists, log2_pages);
+      vec_validate_aligned (rv, (1 << log2_pages) - 1, CLIB_CACHE_LINE_BYTES);
+      clib_mem_set_heap (oldheap);
+      goto initialize;
+    }
+  rv = h->freelists[log2_pages];
+  h->freelists[log2_pages] = rv->next_free;
+
+initialize:
+  ASSERT (rv);
+  ASSERT (vec_len (rv) == (1 << log2_pages));
+  /*
+   * Latest gcc complains that the length arg is zero
+   * if we replace (1<<log2_pages) with vec_len(rv).
+   * No clue.
+   */
+  memset (rv, 0xff, sizeof (*rv) * (1 << log2_pages));
+  return rv;
+}
+
+static void
+BV (value_free) (BVT (clib_bihash) * h, BVT (clib_bihash_value) * v)
+{
+  u32 log2_pages;
+
+  ASSERT (h->writer_lock[0]);
+
+  log2_pages = min_log2 (vec_len (v));
+
+  ASSERT (vec_len (h->freelists) > log2_pages);
+
+  v->next_free = h->freelists[log2_pages];
+  h->freelists[log2_pages] = v;
+}
+
+static inline void
+BV (make_working_copy) (BVT (clib_bihash) * h, clib_bihash_bucket_t * b)
+{
+  BVT (clib_bihash_value) * v;
+  clib_bihash_bucket_t working_bucket __attribute__ ((aligned (8)));
+  void *oldheap;
+  BVT (clib_bihash_value) * working_copy;
+  u32 cpu_number = os_get_cpu_number ();
+
+  if (cpu_number >= vec_len (h->working_copies))
+    {
+      oldheap = clib_mem_set_heap (h->mheap);
+      vec_validate (h->working_copies, cpu_number);
+      clib_mem_set_heap (oldheap);
+    }
+
+  /*
+   * working_copies are per-cpu so that near-simultaneous
+   * updates from multiple threads will not result in sporadic, spurious
+   * lookup failures.
+   */
+  working_copy = h->working_copies[cpu_number];
+
+  h->saved_bucket.as_u64 = b->as_u64;
+  oldheap = clib_mem_set_heap (h->mheap);
+
+  if ((1 << b->log2_pages) > vec_len (working_copy))
+    {
+      vec_validate_aligned (working_copy, (1 << b->log2_pages) - 1,
+			    sizeof (u64));
+      h->working_copies[cpu_number] = working_copy;
+    }
+
+  _vec_len (working_copy) = 1 << b->log2_pages;
+  clib_mem_set_heap (oldheap);
+
+  v = BV (clib_bihash_get_value) (h, b->offset);
+
+  clib_memcpy (working_copy, v, sizeof (*v) * (1 << b->log2_pages));
+  working_bucket.as_u64 = b->as_u64;
+  working_bucket.offset = BV (clib_bihash_get_offset) (h, working_copy);
+  CLIB_MEMORY_BARRIER ();
+  b->as_u64 = working_bucket.as_u64;
+  h->working_copies[cpu_number] = working_copy;
+}
+
+static
+BVT (clib_bihash_value) *
+BV (split_and_rehash)
+  (BVT (clib_bihash) * h,
+   BVT (clib_bihash_value) * old_values, u32 new_log2_pages)
+{
+  BVT (clib_bihash_value) * new_values, *v, *new_v;
+  int i, j, k;
+
+  new_values = BV (value_alloc) (h, new_log2_pages);
+
+  v = old_values;
+  for (i = 0; i < vec_len (old_values); i++)
+    {
+      u64 new_hash;
+
+      for (j = 0; j < BIHASH_KVP_PER_PAGE; j++)
+	{
+	  if (BV (clib_bihash_is_free) (&(v->kvp[j])) == 0)
+	    {
+	      new_hash = BV (clib_bihash_hash) (&(v->kvp[j]));
+	      new_hash >>= h->log2_nbuckets;
+	      new_hash &= (1 << new_log2_pages) - 1;
+
+	      new_v = &new_values[new_hash];
+
+	      for (k = 0; k < BIHASH_KVP_PER_PAGE; k++)
+		{
+		  if (BV (clib_bihash_is_free) (&(new_v->kvp[k])))
+		    {
+		      clib_memcpy (&(new_v->kvp[k]), &(v->kvp[j]),
+				   sizeof (new_v->kvp[k]));
+		      goto doublebreak;
+		    }
+		}
+	      /* Crap. Tell caller to try again */
+	      BV (value_free) (h, new_values);
+	      return 0;
+	    }
+	doublebreak:
+	  ;
+	}
+      v++;
+    }
+  return new_values;
+}
+
+int BV (clib_bihash_add_del)
+  (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add)
+{
+  u32 bucket_index;
+  clib_bihash_bucket_t *b, tmp_b;
+  BVT (clib_bihash_value) * v, *new_v, *save_new_v, *working_copy;
+  u32 value_index;
+  int rv = 0;
+  int i;
+  u64 hash, new_hash;
+  u32 new_log2_pages;
+  u32 cpu_number = os_get_cpu_number ();
+
+  hash = BV (clib_bihash_hash) (add_v);
+
+  bucket_index = hash & (h->nbuckets - 1);
+  b = &h->buckets[bucket_index];
+
+  hash >>= h->log2_nbuckets;
+
+  while (__sync_lock_test_and_set (h->writer_lock, 1))
+    ;
+
+  /* First elt in the bucket? */
+  if (b->offset == 0)
+    {
+      if (is_add == 0)
+	{
+	  rv = -1;
+	  goto unlock;
+	}
+
+      v = BV (value_alloc) (h, 0);
+      *v->kvp = *add_v;
+      tmp_b.as_u64 = 0;
+      tmp_b.offset = BV (clib_bihash_get_offset) (h, v);
+
+      b->as_u64 = tmp_b.as_u64;
+      goto unlock;
+    }
+
+  BV (make_working_copy) (h, b);
+
+  v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset);
+  value_index = hash & ((1 << h->saved_bucket.log2_pages) - 1);
+  v += value_index;
+
+  if (is_add)
+    {
+      /*
+       * For obvious (in hindsight) reasons, see if we're supposed to
+       * replace an existing key, then look for an empty slot.
+       */
+      for (i = 0; i < BIHASH_KVP_PER_PAGE; i++)
+	{
+	  if (!memcmp (&(v->kvp[i]), &add_v->key, sizeof (add_v->key)))
+	    {
+	      clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v));
+	      CLIB_MEMORY_BARRIER ();
+	      /* Restore the previous (k,v) pairs */
+	      b->as_u64 = h->saved_bucket.as_u64;
+	      goto unlock;
+	    }
+	}
+      for (i = 0; i < BIHASH_KVP_PER_PAGE; i++)
+	{
+	  if (BV (clib_bihash_is_free) (&(v->kvp[i])))
+	    {
+	      clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v));
+	      CLIB_MEMORY_BARRIER ();
+	      b->as_u64 = h->saved_bucket.as_u64;
+	      goto unlock;
+	    }
+	}
+      /* no room at the inn... split case... */
+    }
+  else
+    {
+      for (i = 0; i < BIHASH_KVP_PER_PAGE; i++)
+	{
+	  if (!memcmp (&(v->kvp[i]), &add_v->key, sizeof (add_v->key)))
+	    {
+	      memset (&(v->kvp[i]), 0xff, sizeof (*(add_v)));
+	      CLIB_MEMORY_BARRIER ();
+	      b->as_u64 = h->saved_bucket.as_u64;
+	      goto unlock;
+	    }
+	}
+      rv = -3;
+      b->as_u64 = h->saved_bucket.as_u64;
+      goto unlock;
+    }
+
+  new_log2_pages = h->saved_bucket.log2_pages + 1;
+
+expand_again:
+  working_copy = h->working_copies[cpu_number];
+  new_v = BV (split_and_rehash) (h, working_copy, new_log2_pages);
+  if (new_v == 0)
+    {
+      new_log2_pages++;
+      goto expand_again;
+    }
+
+  /* Try to add the new entry */
+  save_new_v = new_v;
+  new_hash = BV (clib_bihash_hash) (add_v);
+  new_hash >>= h->log2_nbuckets;
+  new_hash &= (1 << min_log2 (vec_len (new_v))) - 1;
+  new_v += new_hash;
+
+  for (i = 0; i < BIHASH_KVP_PER_PAGE; i++)
+    {
+      if (BV (clib_bihash_is_free) (&(new_v->kvp[i])))
+	{
+	  clib_memcpy (&(new_v->kvp[i]), add_v, sizeof (*add_v));
+	  goto expand_ok;
+	}
+    }
+  /* Crap. Try again */
+  new_log2_pages++;
+  BV (value_free) (h, save_new_v);
+  goto expand_again;
+
+expand_ok:
+  tmp_b.log2_pages = min_log2 (vec_len (save_new_v));
+  tmp_b.offset = BV (clib_bihash_get_offset) (h, save_new_v);
+  CLIB_MEMORY_BARRIER ();
+  b->as_u64 = tmp_b.as_u64;
+  v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset);
+  BV (value_free) (h, v);
+
+unlock:
+  CLIB_MEMORY_BARRIER ();
+  h->writer_lock[0] = 0;
+  return rv;
+}
+
+int BV (clib_bihash_search)
+  (const BVT (clib_bihash) * h,
+   BVT (clib_bihash_kv) * search_key, BVT (clib_bihash_kv) * valuep)
+{
+  u64 hash;
+  u32 bucket_index;
+  uword value_index;
+  BVT (clib_bihash_value) * v;
+  clib_bihash_bucket_t *b;
+  int i;
+
+  ASSERT (valuep);
+
+  hash = BV (clib_bihash_hash) (search_key);
+
+  bucket_index = hash & (h->nbuckets - 1);
+  b = &h->buckets[bucket_index];
+
+  if (b->offset == 0)
+    return -1;
+
+  hash >>= h->log2_nbuckets;
+
+  v = BV (clib_bihash_get_value) (h, b->offset);
+  value_index = hash & ((1 << b->log2_pages) - 1);
+  v += value_index;
+
+  for (i = 0; i < BIHASH_KVP_PER_PAGE; i++)
+    {
+      if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key))
+	{
+	  *valuep = v->kvp[i];
+	  return 0;
+	}
+    }
+  return -1;
+}
+
+u8 *BV (format_bihash) (u8 * s, va_list * args)
+{
+  BVT (clib_bihash) * h = va_arg (*args, BVT (clib_bihash) *);
+  int verbose = va_arg (*args, int);
+  clib_bihash_bucket_t *b;
+  BVT (clib_bihash_value) * v;
+  int i, j, k;
+  u64 active_elements = 0;
+
+  s = format (s, "Hash table %s\n", h->name ? h->name : (u8 *) "(unnamed)");
+
+  for (i = 0; i < h->nbuckets; i++)
+    {
+      b = &h->buckets[i];
+      if (b->offset == 0)
+	{
+	  if (verbose > 1)
+	    s = format (s, "[%d]: empty\n", i);
+	  continue;
+	}
+
+      if (verbose)
+	{
+	  s = format (s, "[%d]: heap offset %d, len %d\n", i,
+		      b->offset, (1 << b->log2_pages));
+	}
+
+      v = BV (clib_bihash_get_value) (h, b->offset);
+      for (j = 0; j < (1 << b->log2_pages); j++)
+	{
+	  for (k = 0; k < BIHASH_KVP_PER_PAGE; k++)
+	    {
+	      if (BV (clib_bihash_is_free) (&v->kvp[k]))
+		{
+		  if (verbose > 1)
+		    s = format (s, "    %d: empty\n",
+				j * BIHASH_KVP_PER_PAGE + k);
+		  continue;
+		}
+	      if (verbose)
+		{
+		  s = format (s, "    %d: %U\n",
+			      j * BIHASH_KVP_PER_PAGE + k,
+			      BV (format_bihash_kvp), &(v->kvp[k]));
+		}
+	      active_elements++;
+	    }
+	  v++;
+	}
+    }
+
+  s = format (s, "    %lld active elements\n", active_elements);
+  s = format (s, "    %d free lists\n", vec_len (h->freelists));
+
+  return s;
+}
+
+void BV (clib_bihash_foreach_key_value_pair)
+  (BVT (clib_bihash) * h, void *callback, void *arg)
+{
+  int i, j, k;
+  clib_bihash_bucket_t *b;
+  BVT (clib_bihash_value) * v;
+  void (*fp) (BVT (clib_bihash_kv) *, void *) = callback;
+
+  for (i = 0; i < h->nbuckets; i++)
+    {
+      b = &h->buckets[i];
+      if (b->offset == 0)
+	continue;
+
+      v = BV (clib_bihash_get_value) (h, b->offset);
+      for (j = 0; j < (1 << b->log2_pages); j++)
+	{
+	  for (k = 0; k < BIHASH_KVP_PER_PAGE; k++)
+	    {
+	      if (BV (clib_bihash_is_free) (&v->kvp[k]))
+		continue;
+
+	      (*fp) (&v->kvp[k], arg);
+	    }
+	  v++;
+	}
+    }
+}
+
+/** @endcond */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */