| /* |
| * Copyright (c) 2016, 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_GC_SHARED_PRESERVEDMARKS_HPP |
| #define SHARE_VM_GC_SHARED_PRESERVEDMARKS_HPP |
| |
| #include "memory/allocation.hpp" |
| #include "memory/padded.hpp" |
| #include "oops/oop.hpp" |
| #include "utilities/stack.hpp" |
| |
| class PreservedMarksSet; |
| class WorkGang; |
| |
| class PreservedMarks VALUE_OBJ_CLASS_SPEC { |
| private: |
| class OopAndMarkOop { |
| private: |
| oop _o; |
| markOop _m; |
| |
| public: |
| OopAndMarkOop(oop obj, markOop m) : _o(obj), _m(m) { } |
| |
| void set_mark() const { |
| _o->set_mark(_m); |
| } |
| }; |
| typedef Stack<OopAndMarkOop, mtGC> OopAndMarkOopStack; |
| |
| OopAndMarkOopStack _stack; |
| |
| inline bool should_preserve_mark(oop obj, markOop m) const; |
| inline void push(oop obj, markOop m); |
| |
| public: |
| size_t size() const { return _stack.size(); } |
| inline void push_if_necessary(oop obj, markOop m); |
| // Iterate over the stack, restore all preserved marks, and |
| // reclaim the memory taken up by the stack segments. |
| void restore(); |
| |
| void restore_and_increment(volatile size_t* const _total_size_addr); |
| inline static void init_forwarded_mark(oop obj); |
| |
| // Assert the stack is empty and has no cached segments. |
| void assert_empty() PRODUCT_RETURN; |
| |
| inline PreservedMarks(); |
| ~PreservedMarks() { assert_empty(); } |
| }; |
| |
| class RemoveForwardedPointerClosure: public ObjectClosure { |
| public: |
| virtual void do_object(oop obj); |
| }; |
| |
| class RestorePreservedMarksTaskExecutor { |
| public: |
| void virtual restore(PreservedMarksSet* preserved_marks_set, |
| volatile size_t* total_size_addr) = 0; |
| }; |
| |
| class SharedRestorePreservedMarksTaskExecutor : public RestorePreservedMarksTaskExecutor { |
| private: |
| WorkGang* _workers; |
| |
| public: |
| SharedRestorePreservedMarksTaskExecutor(WorkGang* workers) : _workers(workers) { } |
| |
| void restore(PreservedMarksSet* preserved_marks_set, |
| volatile size_t* total_size_addr); |
| |
| }; |
| |
| class PreservedMarksSet : public CHeapObj<mtGC> { |
| private: |
| // true -> _stacks will be allocated in the C heap |
| // false -> _stacks will be allocated in the resource arena |
| const bool _in_c_heap; |
| |
| // Number of stacks we have allocated (typically, one stack per GC worker). |
| // This should be >= 1 if the stacks have been initialized, |
| // or == 0 if they have not. |
| uint _num; |
| |
| // Stack array (typically, one stack per GC worker) of length _num. |
| // This should be != NULL if the stacks have been initialized, |
| // or == NULL if they have not. |
| Padded<PreservedMarks>* _stacks; |
| |
| public: |
| uint num() const { return _num; } |
| |
| // Return the i'th stack. |
| PreservedMarks* get(uint i = 0) const { |
| assert(_num > 0 && _stacks != NULL, "stacks should have been initialized"); |
| assert(i < _num, "pre-condition"); |
| return (_stacks + i); |
| } |
| |
| // Allocate stack array. |
| void init(uint num); |
| |
| // Iterate over all stacks, restore all preserved marks, and reclaim |
| // the memory taken up by the stack segments. |
| // Supported executors: SharedRestorePreservedMarksTaskExecutor (Serial, CMS, G1), |
| // PSRestorePreservedMarksTaskExecutor (PS). |
| inline void restore(RestorePreservedMarksTaskExecutor* executor); |
| |
| // Reclaim stack array. |
| void reclaim(); |
| |
| // Assert all the stacks are empty and have no cached segments. |
| void assert_empty() PRODUCT_RETURN; |
| |
| PreservedMarksSet(bool in_c_heap) |
| : _in_c_heap(in_c_heap), _num(0), _stacks(NULL) { } |
| |
| ~PreservedMarksSet() { |
| assert(_stacks == NULL && _num == 0, "stacks should have been reclaimed"); |
| } |
| }; |
| |
| #endif // SHARE_VM_GC_SHARED_PRESERVEDMARKS_HPP |