1 /* 2 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_JFR_UTILITIES_JFREPOCHQUEUE_HPP 26 #define SHARE_JFR_UTILITIES_JFREPOCHQUEUE_HPP 27 28 #include "jfr/recorder/storage/jfrEpochStorage.hpp" 29 30 /* 31 * An ElmentPolicy template template argument provides the implementation for how elements 32 * associated with the queue is encoded and managed by exposing the following members: 33 * 34 * ElmentPolicy::Type the type of the element to be stored in the queue. 35 * size_t element_size(Type* t); per element storage size requirement. 36 * void store_element(Type* t, Buffer* buffer); encode and store element of Type into storage of type Buffer. 37 * Buffer* thread_local_storage(Thread* thread); quick access to thread local storage. 38 * void set_thread_lcoal_storage(Buffer* buffer, Thread* thread); store back capability for newly acquired storage. 39 * 40 * The ElementPolicy is also the callback when iterating elements of the queue. 41 * The iteration callback signature to be provided by the policy class: 42 * 43 * size_t operator()(const u1* next_element, Callback& callback, bool previous_epoch = false); 44 */ 45 template <template <typename> class ElementPolicy> 46 class JfrEpochQueue : public JfrCHeapObj { 47 public: 48 typedef JfrEpochStorage::Buffer Buffer; 49 typedef JfrEpochStorage::BufferPtr BufferPtr; 50 typedef typename ElementPolicy<Buffer>::Type Type; 51 typedef const Type* TypePtr; 52 JfrEpochQueue(); 53 ~JfrEpochQueue(); 54 bool initialize(size_t min_buffer_size, size_t free_list_cache_count_limit, size_t cache_prealloc_count); 55 void enqueue(TypePtr t); 56 template <typename Callback> 57 void iterate(Callback& callback, bool previous_epoch = false); 58 private: 59 typedef ElementPolicy<Buffer> Policy; 60 Policy _policy; 61 JfrEpochStorage* _storage; 62 BufferPtr storage_for_element(TypePtr t, size_t element_size); 63 64 template <typename Callback> 65 class ElementDispatch { 66 private: 67 Callback& _callback; 68 Policy& _policy; 69 public: 70 typedef Buffer Type; 71 ElementDispatch(Callback& callback, Policy& policy); 72 size_t operator()(const u1* element, bool previous_epoch); 73 }; 74 }; 75 76 #endif // SHARE_JFR_UTILITIES_JFREPOCHQUEUE_HPP 77