1 // Copyright 2015 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_LOCKED_QUEUE_INL_ 6 #define V8_LOCKED_QUEUE_INL_ 7 8 #include "src/base/atomic-utils.h" 9 #include "src/locked-queue.h" 10 11 namespace v8 { 12 namespace internal { 13 14 template <typename Record> 15 struct LockedQueue<Record>::Node : Malloced { 16 Node() : next(nullptr) {} 17 Record value; 18 base::AtomicValue<Node*> next; 19 }; 20 21 22 template <typename Record> 23 inline LockedQueue<Record>::LockedQueue() { 24 head_ = new Node(); 25 CHECK(head_ != nullptr); 26 tail_ = head_; 27 } 28 29 30 template <typename Record> 31 inline LockedQueue<Record>::~LockedQueue() { 32 // Destroy all remaining nodes. Note that we do not destroy the actual values. 33 Node* old_node = nullptr; 34 Node* cur_node = head_; 35 while (cur_node != nullptr) { 36 old_node = cur_node; 37 cur_node = cur_node->next.Value(); 38 delete old_node; 39 } 40 } 41 42 43 template <typename Record> 44 inline void LockedQueue<Record>::Enqueue(const Record& record) { 45 Node* n = new Node(); 46 CHECK(n != nullptr); 47 n->value = record; 48 { 49 base::LockGuard<base::Mutex> guard(&tail_mutex_); 50 tail_->next.SetValue(n); 51 tail_ = n; 52 } 53 } 54 55 56 template <typename Record> 57 inline bool LockedQueue<Record>::Dequeue(Record* record) { 58 Node* old_head = nullptr; 59 { 60 base::LockGuard<base::Mutex> guard(&head_mutex_); 61 old_head = head_; 62 Node* const next_node = head_->next.Value(); 63 if (next_node == nullptr) return false; 64 *record = next_node->value; 65 head_ = next_node; 66 } 67 delete old_head; 68 return true; 69 } 70 71 72 template <typename Record> 73 inline bool LockedQueue<Record>::IsEmpty() const { 74 base::LockGuard<base::Mutex> guard(&head_mutex_); 75 return head_->next.Value() == nullptr; 76 } 77 78 79 template <typename Record> 80 inline bool LockedQueue<Record>::Peek(Record* record) const { 81 base::LockGuard<base::Mutex> guard(&head_mutex_); 82 Node* const next_node = head_->next.Value(); 83 if (next_node == nullptr) return false; 84 *record = next_node->value; 85 return true; 86 } 87 88 } // namespace internal 89 } // namespace v8 90 91 #endif // V8_LOCKED_QUEUE_INL_ 92
