1 /* 2 * Copyright (c) 2016, 2017, 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_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP 26 #define SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP 27 28 #include "oops/oopsHierarchy.hpp" 29 #include "memory/allocation.hpp" 30 31 class G1CMTask; 32 33 // Helper class to mark through large objArrays during marking in an efficient way. 34 // Instead of pushing large object arrays, we push continuations onto the 35 // mark stack. These continuations are identified by having their LSB set. 36 // This allows incremental processing of large objects. 37 class G1CMObjArrayProcessor VALUE_OBJ_CLASS_SPEC { 38 private: 39 // Reference to the task for doing the actual work. 40 G1CMTask* _task; 41 42 // Push the continuation at the given address onto the mark stack. 43 void push_array_slice(HeapWord* addr); 44 45 // Process (apply the closure) on the given continuation of the given objArray. 46 size_t process_array_slice(objArrayOop const obj, HeapWord* start_from, size_t remaining); 47 public: 48 static bool should_be_sliced(oop obj); 49 50 G1CMObjArrayProcessor(G1CMTask* task) : _task(task) { 51 } 52 53 // Process the given continuation "oop". Returns the number of words scanned. 54 size_t process_slice(HeapWord* slice); 55 // Start processing the given objArrayOop by scanning the header and pushing its 56 // continuation. 57 size_t process_obj(oop obj); 58 }; 59 60 #endif /* SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP */