2 * Copyright 2016 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include <folly/experimental/hazptr/debug.h>
19 #include <folly/experimental/hazptr/hazptr.h>
29 using T = std::string;
30 class Node : public hazptr_obj_base<Node> {
33 Node() : val_(T()) { DEBUG_PRINT(this << " " << val_); }
34 explicit Node(T v) : val_(v) { DEBUG_PRINT(this << " " << v); }
36 ~Node() { DEBUG_PRINT(this); }
39 std::atomic<Node*> p_ = {new Node()};
44 DEBUG_PRINT(this << " " << p_.load());
48 bool cas(T& u, T& v) {
49 DEBUG_PRINT(this << " " << u << " " << v);
50 Node* n = new Node(v);
51 hazptr_owner<Node> hptr;
54 if (!hptr.protect(p, p_)) continue;
55 if (p->val_ != u) { delete n; return false; }
56 if (p_.compare_exchange_weak(p, n)) break;
60 DEBUG_PRINT(this << " " << p << " " << u << " " << n << " " << v);
65 } // namespace folly {
66 } // namespace hazptr {