Merge github.com:grpc/grpc into write_completion

1 files changed, 305 insertions, 0 deletions

diff --git a/src/core/ext/census/intrusive_hash_map.c b/src/core/ext/census/intrusive_hash_map.c
new file mode 100644
index 0000000000..7930486963
--- /dev/null
+++ b/src/core/ext/census/intrusive_hash_map.c
@@ -0,0 +1,305 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * 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 "src/core/ext/census/intrusive_hash_map.h"
+#include <string.h>
+
+extern bool hm_index_compare(const hm_index *A, const hm_index *B);
+
+/* Simple hashing function that takes lower 32 bits. */
+static __inline uint32_t chunked_vector_hasher(uint64_t key) {
+  return (uint32_t)key;
+}
+
+/* Vector chunks are 1MiB divided by pointer size. */
+static const size_t VECTOR_CHUNK_SIZE = (1 << 20) / sizeof(void *);
+
+/* Helper functions which return buckets from the chunked vector. */
+static __inline void **get_mutable_bucket(const chunked_vector *buckets,
+                                          uint32_t index) {
+  if (index < VECTOR_CHUNK_SIZE) {
+    return &buckets->first_[index];
+  }
+  size_t rest_index = (index - VECTOR_CHUNK_SIZE) / VECTOR_CHUNK_SIZE;
+  return &buckets->rest_[rest_index][index % VECTOR_CHUNK_SIZE];
+}
+
+static __inline void *get_bucket(const chunked_vector *buckets,
+                                 uint32_t index) {
+  if (index < VECTOR_CHUNK_SIZE) {
+    return buckets->first_[index];
+  }
+  size_t rest_index = (index - VECTOR_CHUNK_SIZE) / VECTOR_CHUNK_SIZE;
+  return buckets->rest_[rest_index][index % VECTOR_CHUNK_SIZE];
+}
+
+/* Helper function. */
+static __inline size_t RestSize(const chunked_vector *vec) {
+  return (vec->size_ <= VECTOR_CHUNK_SIZE)
+             ? 0
+             : (vec->size_ - VECTOR_CHUNK_SIZE - 1) / VECTOR_CHUNK_SIZE + 1;
+}
+
+/* Initialize chunked vector to size of 0. */
+static void chunked_vector_init(chunked_vector *vec) {
+  vec->size_ = 0;
+  vec->first_ = NULL;
+  vec->rest_ = NULL;
+}
+
+/* Clear chunked vector and free all memory that has been allocated then
+   initialize chunked vector. */
+static void chunked_vector_clear(chunked_vector *vec) {
+  if (vec->first_ != NULL) {
+    gpr_free(vec->first_);
+  }
+  if (vec->rest_ != NULL) {
+    size_t rest_size = RestSize(vec);
+    for (size_t i = 0; i < rest_size; ++i) {
+      if (vec->rest_[i] != NULL) {
+        gpr_free(vec->rest_[i]);
+      }
+    }
+    gpr_free(vec->rest_);
+  }
+  chunked_vector_init(vec);
+}
+
+/* Clear chunked vector and then resize it to n entries. Allow the first 1MB to
+   be read w/o an extra cache miss. The rest of the elements are stored in an
+   array of arrays to avoid large mallocs. */
+static void chunked_vector_reset(chunked_vector *vec, size_t n) {
+  chunked_vector_clear(vec);
+  vec->size_ = n;
+  if (n <= VECTOR_CHUNK_SIZE) {
+    vec->first_ = (void **)gpr_malloc(sizeof(void *) * n);
+    memset(vec->first_, 0, sizeof(void *) * n);
+  } else {
+    vec->first_ = (void **)gpr_malloc(sizeof(void *) * VECTOR_CHUNK_SIZE);
+    memset(vec->first_, 0, sizeof(void *) * VECTOR_CHUNK_SIZE);
+    size_t rest_size = RestSize(vec);
+    vec->rest_ = (void ***)gpr_malloc(sizeof(void **) * rest_size);
+    memset(vec->rest_, 0, sizeof(void **) * rest_size);
+    int i = 0;
+    n -= VECTOR_CHUNK_SIZE;
+    while (n > 0) {
+      size_t this_size = GPR_MIN(n, VECTOR_CHUNK_SIZE);
+      vec->rest_[i] = (void **)gpr_malloc(sizeof(void *) * this_size);
+      memset(vec->rest_[i], 0, sizeof(void *) * this_size);
+      n -= this_size;
+      ++i;
+    }
+  }
+}
+
+void intrusive_hash_map_init(intrusive_hash_map *hash_map,
+                             uint32_t initial_log2_table_size) {
+  hash_map->log2_num_buckets = initial_log2_table_size;
+  hash_map->num_items = 0;
+  uint32_t num_buckets = (uint32_t)1 << hash_map->log2_num_buckets;
+  hash_map->extend_threshold = num_buckets >> 1;
+  chunked_vector_init(&hash_map->buckets);
+  chunked_vector_reset(&hash_map->buckets, num_buckets);
+  hash_map->hash_mask = num_buckets - 1;
+}
+
+bool intrusive_hash_map_empty(const intrusive_hash_map *hash_map) {
+  return hash_map->num_items == 0;
+}
+
+size_t intrusive_hash_map_size(const intrusive_hash_map *hash_map) {
+  return hash_map->num_items;
+}
+
+void intrusive_hash_map_end(const intrusive_hash_map *hash_map, hm_index *idx) {
+  idx->bucket_index = (uint32_t)hash_map->buckets.size_;
+  GPR_ASSERT(idx->bucket_index <= UINT32_MAX);
+  idx->item = NULL;
+}
+
+void intrusive_hash_map_next(const intrusive_hash_map *hash_map,
+                             hm_index *idx) {
+  idx->item = idx->item->hash_link;
+  while (idx->item == NULL) {
+    idx->bucket_index++;
+    if (idx->bucket_index >= hash_map->buckets.size_) {
+      /* Reached end of table. */
+      idx->item = NULL;
+      return;
+    }
+    idx->item = (hm_item *)get_bucket(&hash_map->buckets, idx->bucket_index);
+  }
+}
+
+void intrusive_hash_map_begin(const intrusive_hash_map *hash_map,
+                              hm_index *idx) {
+  for (uint32_t i = 0; i < hash_map->buckets.size_; ++i) {
+    if (get_bucket(&hash_map->buckets, i) != NULL) {
+      idx->bucket_index = i;
+      idx->item = (hm_item *)get_bucket(&hash_map->buckets, i);
+      return;
+    }
+  }
+  intrusive_hash_map_end(hash_map, idx);
+}
+
+hm_item *intrusive_hash_map_find(const intrusive_hash_map *hash_map,
+                                 uint64_t key) {
+  uint32_t index = chunked_vector_hasher(key) & hash_map->hash_mask;
+
+  hm_item *p = (hm_item *)get_bucket(&hash_map->buckets, index);
+  while (p != NULL) {
+    if (key == p->key) {
+      return p;
+    }
+    p = p->hash_link;
+  }
+  return NULL;
+}
+
+hm_item *intrusive_hash_map_erase(intrusive_hash_map *hash_map, uint64_t key) {
+  uint32_t index = chunked_vector_hasher(key) & hash_map->hash_mask;
+
+  hm_item **slot = (hm_item **)get_mutable_bucket(&hash_map->buckets, index);
+  hm_item *p = *slot;
+  if (p == NULL) {
+    return NULL;
+  }
+
+  if (key == p->key) {
+    *slot = p->hash_link;
+    p->hash_link = NULL;
+    hash_map->num_items--;
+    return p;
+  }
+
+  hm_item *prev = p;
+  p = p->hash_link;
+
+  while (p) {
+    if (key == p->key) {
+      prev->hash_link = p->hash_link;
+      p->hash_link = NULL;
+      hash_map->num_items--;
+      return p;
+    }
+    prev = p;
+    p = p->hash_link;
+  }
+  return NULL;
+}
+
+/* Insert an hm_item* into the underlying chunked vector. hash_mask is
+ * array_size-1. Returns true if it is a new hm_item and false if the hm_item
+ * already existed.
+ */
+static __inline bool intrusive_hash_map_internal_insert(chunked_vector *buckets,
+                                                        uint32_t hash_mask,
+                                                        hm_item *item) {
+  const uint64_t key = item->key;
+  uint32_t index = chunked_vector_hasher(key) & hash_mask;
+  hm_item **slot = (hm_item **)get_mutable_bucket(buckets, index);
+  hm_item *p = *slot;
+  item->hash_link = p;
+
+  /* Check to see if key already exists. */
+  while (p) {
+    if (p->key == key) {
+      return false;
+    }
+    p = p->hash_link;
+  }
+
+  /* Otherwise add new entry. */
+  *slot = item;
+  return true;
+}
+
+/* Extend the allocated number of elements in the hash map by a factor of 2. */
+void intrusive_hash_map_extend(intrusive_hash_map *hash_map) {
+  uint32_t new_log2_num_buckets = 1 + hash_map->log2_num_buckets;
+  uint32_t new_num_buckets = (uint32_t)1 << new_log2_num_buckets;
+  GPR_ASSERT(new_num_buckets <= UINT32_MAX && new_num_buckets > 0);
+  chunked_vector new_buckets;
+  chunked_vector_init(&new_buckets);
+  chunked_vector_reset(&new_buckets, new_num_buckets);
+  uint32_t new_hash_mask = new_num_buckets - 1;
+
+  hm_index cur_idx;
+  hm_index end_idx;
+  intrusive_hash_map_end(hash_map, &end_idx);
+  intrusive_hash_map_begin(hash_map, &cur_idx);
+  while (!hm_index_compare(&cur_idx, &end_idx)) {
+    hm_item *new_item = cur_idx.item;
+    intrusive_hash_map_next(hash_map, &cur_idx);
+    intrusive_hash_map_internal_insert(&new_buckets, new_hash_mask, new_item);
+  }
+
+  /* Set values for new chunked_vector. extend_threshold is set to half of
+   * new_num_buckets. */
+  hash_map->log2_num_buckets = new_log2_num_buckets;
+  chunked_vector_clear(&hash_map->buckets);
+  hash_map->buckets = new_buckets;
+  hash_map->hash_mask = new_hash_mask;
+  hash_map->extend_threshold = new_num_buckets >> 1;
+}
+
+/* Insert a hm_item. The hm_item must remain live until it is removed from the
+   table. This object does not take the ownership of hm_item. The caller must
+   remove this hm_item from the table and delete it before this table is
+   deleted. If hm_item exists already num_items is not changed. */
+bool intrusive_hash_map_insert(intrusive_hash_map *hash_map, hm_item *item) {
+  if (hash_map->num_items >= hash_map->extend_threshold) {
+    intrusive_hash_map_extend(hash_map);
+  }
+  if (intrusive_hash_map_internal_insert(&hash_map->buckets,
+                                         hash_map->hash_mask, item)) {
+    hash_map->num_items++;
+    return true;
+  }
+  return false;
+}
+
+void intrusive_hash_map_clear(intrusive_hash_map *hash_map,
+                              void (*free_object)(void *)) {
+  hm_index cur;
+  hm_index end;
+  intrusive_hash_map_end(hash_map, &end);
+  intrusive_hash_map_begin(hash_map, &cur);
+
+  while (!hm_index_compare(&cur, &end)) {
+    hm_index next = cur;
+    intrusive_hash_map_next(hash_map, &next);
+    if (cur.item != NULL) {
+      hm_item *item = intrusive_hash_map_erase(hash_map, cur.item->key);
+      (*free_object)((void *)item);
+      gpr_free(item);
+    }
+    cur = next;
+  }
+}
+
+void intrusive_hash_map_free(intrusive_hash_map *hash_map,
+                             void (*free_object)(void *)) {
+  intrusive_hash_map_clear(hash_map, (*free_object));
+  hash_map->num_items = 0;
+  hash_map->extend_threshold = 0;
+  hash_map->log2_num_buckets = 0;
+  hash_map->hash_mask = 0;
+  chunked_vector_clear(&hash_map->buckets);
+}