--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/utilities/resourceHash.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_RESOURCEHASH_HPP
+#define SHARE_VM_UTILITIES_RESOURCEHASH_HPP
+
+#include "memory/allocation.hpp"
+
+template<typename K> struct ResourceHashtableFns {
+ typedef unsigned (*hash_fn)(K const&);
+ typedef bool (*equals_fn)(K const&, K const&);
+};
+
+template<typename K> unsigned primitive_hash(const K& k) {
+ unsigned hash = (unsigned)((uintptr_t)k);
+ return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
+}
+
+template<typename K> bool primitive_equals(const K& k0, const K& k1) {
+ return k0 == k1;
+}
+
+template<
+ typename K, typename V,
+ // xlC does not compile this:
+ // http://stackoverflow.com/questions/8532961/template-argument-of-type-that-is-defined-by-inner-typedef-from-other-template-c
+ //typename ResourceHashtableFns<K>::hash_fn HASH = primitive_hash<K>,
+ //typename ResourceHashtableFns<K>::equals_fn EQUALS = primitive_equals<K>,
+ unsigned (*HASH) (K const&) = primitive_hash<K>,
+ bool (*EQUALS)(K const&, K const&) = primitive_equals<K>,
+ unsigned SIZE = 256,
+ ResourceObj::allocation_type ALLOC_TYPE = ResourceObj::RESOURCE_AREA,
+ MEMFLAGS MEM_TYPE = mtInternal
+ >
+class ResourceHashtable : public ResourceObj {
+ private:
+
+ class Node : public ResourceObj {
+ public:
+ unsigned _hash;
+ K _key;
+ V _value;
+ Node* _next;
+
+ Node(unsigned hash, K const& key, V const& value) :
+ _hash(hash), _key(key), _value(value), _next(NULL) {}
+ };
+
+ Node* _table[SIZE];
+
+ // Returns a pointer to where the node where the value would reside if
+ // it's in the table.
+ Node** lookup_node(unsigned hash, K const& key) {
+ unsigned index = hash % SIZE;
+ Node** ptr = &_table[index];
+ while (*ptr != NULL) {
+ Node* node = *ptr;
+ if (node->_hash == hash && EQUALS(key, node->_key)) {
+ break;
+ }
+ ptr = &(node->_next);
+ }
+ return ptr;
+ }
+
+ Node const** lookup_node(unsigned hash, K const& key) const {
+ return const_cast<Node const**>(
+ const_cast<ResourceHashtable*>(this)->lookup_node(hash, key));
+ }
+
+ public:
+ ResourceHashtable() { memset(_table, 0, SIZE * sizeof(Node*)); }
+
+ ~ResourceHashtable() {
+ if (ALLOC_TYPE == C_HEAP) {
+ Node* const* bucket = _table;
+ while (bucket < &_table[SIZE]) {
+ Node* node = *bucket;
+ while (node != NULL) {
+ Node* cur = node;
+ node = node->_next;
+ delete cur;
+ }
+ ++bucket;
+ }
+ }
+ }
+
+ bool contains(K const& key) const {
+ return get(key) != NULL;
+ }
+
+ V* get(K const& key) const {
+ unsigned hv = HASH(key);
+ Node const** ptr = lookup_node(hv, key);
+ if (*ptr != NULL) {
+ return const_cast<V*>(&(*ptr)->_value);
+ } else {
+ return NULL;
+ }
+ }
+
+ /**
+ * Inserts or replaces a value in the table.
+ * @return: true: if a new item is added
+ * false: if the item already existed and the value is updated
+ */
+ bool put(K const& key, V const& value) {
+ unsigned hv = HASH(key);
+ Node** ptr = lookup_node(hv, key);
+ if (*ptr != NULL) {
+ (*ptr)->_value = value;
+ return false;
+ } else {
+ *ptr = new (ALLOC_TYPE, MEM_TYPE) Node(hv, key, value);
+ return true;
+ }
+ }
+
+ bool remove(K const& key) {
+ unsigned hv = HASH(key);
+ Node** ptr = lookup_node(hv, key);
+
+ Node* node = *ptr;
+ if (node != NULL) {
+ *ptr = node->_next;
+ if (ALLOC_TYPE == C_HEAP) {
+ delete node;
+ }
+ return true;
+ }
+ return false;
+ }
+
+ // ITER contains bool do_entry(K const&, V const&), which will be
+ // called for each entry in the table. If do_entry() returns false,
+ // the iteration is cancelled.
+ template<class ITER>
+ void iterate(ITER* iter) const {
+ Node* const* bucket = _table;
+ while (bucket < &_table[SIZE]) {
+ Node* node = *bucket;
+ while (node != NULL) {
+ bool cont = iter->do_entry(node->_key, node->_value);
+ if (!cont) { return; }
+ node = node->_next;
+ }
+ ++bucket;
+ }
+ }
+
+ static size_t node_size() {
+ return sizeof(Node);
+ }
+};
+
+
+#endif // SHARE_VM_UTILITIES_RESOURCEHASH_HPP