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-rw-r--r--src/vppinfra/bihash_template.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c
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+/*
+ * 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:
+ */