author | johnc |
Thu, 22 Sep 2011 10:57:37 -0700 | |
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/* |
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* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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* |
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*/ |
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#ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |
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#define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |
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#include "memory/referencePolicy.hpp" |
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#include "oops/instanceRefKlass.hpp" |
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// ReferenceProcessor class encapsulates the per-"collector" processing |
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// of java.lang.Reference objects for GC. The interface is useful for supporting |
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// a generational abstraction, in particular when there are multiple |
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// generations that are being independently collected -- possibly |
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// concurrently and/or incrementally. Note, however, that the |
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// ReferenceProcessor class abstracts away from a generational setting |
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// by using only a heap interval (called "span" below), thus allowing |
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// its use in a straightforward manner in a general, non-generational |
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// setting. |
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// |
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// The basic idea is that each ReferenceProcessor object concerns |
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// itself with ("weak") reference processing in a specific "span" |
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// of the heap of interest to a specific collector. Currently, |
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// the span is a convex interval of the heap, but, efficiency |
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// apart, there seems to be no reason it couldn't be extended |
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// (with appropriate modifications) to any "non-convex interval". |
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// forward references |
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class ReferencePolicy; |
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class AbstractRefProcTaskExecutor; |
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// List of discovered references. |
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class DiscoveredList { |
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public: |
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DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { } |
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oop head() const { |
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return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) : |
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_oop_head; |
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} |
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HeapWord* adr_head() { |
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return UseCompressedOops ? (HeapWord*)&_compressed_head : |
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(HeapWord*)&_oop_head; |
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} |
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void set_head(oop o) { |
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if (UseCompressedOops) { |
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// Must compress the head ptr. |
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_compressed_head = oopDesc::encode_heap_oop(o); |
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} else { |
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_oop_head = o; |
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} |
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} |
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bool is_empty() const { return head() == NULL; } |
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size_t length() { return _len; } |
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void set_length(size_t len) { _len = len; } |
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void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); } |
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void dec_length(size_t dec) { _len -= dec; } |
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private: |
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// Set value depending on UseCompressedOops. This could be a template class |
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// but then we have to fix all the instantiations and declarations that use this class. |
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oop _oop_head; |
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narrowOop _compressed_head; |
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size_t _len; |
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}; |
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// Iterator for the list of discovered references. |
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class DiscoveredListIterator { |
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private: |
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DiscoveredList& _refs_list; |
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HeapWord* _prev_next; |
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oop _prev; |
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oop _ref; |
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HeapWord* _discovered_addr; |
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oop _next; |
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HeapWord* _referent_addr; |
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oop _referent; |
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OopClosure* _keep_alive; |
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BoolObjectClosure* _is_alive; |
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DEBUG_ONLY( |
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oop _first_seen; // cyclic linked list check |
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) |
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NOT_PRODUCT( |
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size_t _processed; |
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size_t _removed; |
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) |
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public: |
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inline DiscoveredListIterator(DiscoveredList& refs_list, |
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OopClosure* keep_alive, |
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BoolObjectClosure* is_alive): |
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_refs_list(refs_list), |
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_prev_next(refs_list.adr_head()), |
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_prev(NULL), |
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_ref(refs_list.head()), |
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#ifdef ASSERT |
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_first_seen(refs_list.head()), |
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#endif |
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#ifndef PRODUCT |
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_processed(0), |
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_removed(0), |
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#endif |
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_next(NULL), |
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_keep_alive(keep_alive), |
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_is_alive(is_alive) |
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{ } |
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// End Of List. |
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inline bool has_next() const { return _ref != NULL; } |
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// Get oop to the Reference object. |
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inline oop obj() const { return _ref; } |
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// Get oop to the referent object. |
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inline oop referent() const { return _referent; } |
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// Returns true if referent is alive. |
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inline bool is_referent_alive() const { |
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return _is_alive->do_object_b(_referent); |
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} |
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// Loads data for the current reference. |
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// The "allow_null_referent" argument tells us to allow for the possibility |
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// of a NULL referent in the discovered Reference object. This typically |
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// happens in the case of concurrent collectors that may have done the |
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// discovery concurrently, or interleaved, with mutator execution. |
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void load_ptrs(DEBUG_ONLY(bool allow_null_referent)); |
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// Move to the next discovered reference. |
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inline void next() { |
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_prev_next = _discovered_addr; |
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_prev = _ref; |
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move_to_next(); |
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} |
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// Remove the current reference from the list |
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void remove(); |
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// Make the Reference object active again. |
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void make_active(); |
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|
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// Make the referent alive. |
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inline void make_referent_alive() { |
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if (UseCompressedOops) { |
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_keep_alive->do_oop((narrowOop*)_referent_addr); |
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} else { |
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_keep_alive->do_oop((oop*)_referent_addr); |
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} |
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} |
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|
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// Update the discovered field. |
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inline void update_discovered() { |
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// First _prev_next ref actually points into DiscoveredList (gross). |
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if (UseCompressedOops) { |
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if (!oopDesc::is_null(*(narrowOop*)_prev_next)) { |
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_keep_alive->do_oop((narrowOop*)_prev_next); |
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} |
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} else { |
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if (!oopDesc::is_null(*(oop*)_prev_next)) { |
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_keep_alive->do_oop((oop*)_prev_next); |
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} |
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} |
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} |
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|
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// NULL out referent pointer. |
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void clear_referent(); |
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|
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// Statistics |
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NOT_PRODUCT( |
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inline size_t processed() const { return _processed; } |
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inline size_t removed() const { return _removed; } |
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) |
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193 |
|
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inline void move_to_next() { |
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if (_ref == _next) { |
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// End of the list. |
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_ref = NULL; |
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} else { |
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_ref = _next; |
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} |
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assert(_ref != _first_seen, "cyclic ref_list found"); |
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NOT_PRODUCT(_processed++); |
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} |
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204 |
|
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}; |
1 | 206 |
|
207 |
class ReferenceProcessor : public CHeapObj { |
|
208 |
protected: |
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// Compatibility with pre-4965777 JDK's |
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static bool _pending_list_uses_discovered_field; |
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211 |
|
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MemRegion _span; // (right-open) interval of heap |
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// subject to wkref discovery |
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214 |
|
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bool _discovering_refs; // true when discovery enabled |
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bool _discovery_is_atomic; // if discovery is atomic wrt |
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// other collectors in configuration |
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bool _discovery_is_mt; // true if reference discovery is MT. |
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// If true, setting "next" field of a discovered refs list requires |
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// write barrier(s). (Must be true if used in a collector in which |
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// elements of a discovered list may be moved during discovery: for |
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// example, a collector like Garbage-First that moves objects during a |
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// long-term concurrent marking phase that does weak reference |
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// discovery.) |
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bool _discovered_list_needs_barrier; |
1 | 227 |
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BarrierSet* _bs; // Cached copy of BarrierSet. |
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bool _enqueuing_is_done; // true if all weak references enqueued |
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bool _processing_is_mt; // true during phases when |
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// reference processing is MT. |
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int _next_id; // round-robin mod _num_q counter in |
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// support of work distribution |
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234 |
|
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// For collectors that do not keep GC liveness information |
1 | 236 |
// in the object header, this field holds a closure that |
237 |
// helps the reference processor determine the reachability |
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// of an oop. It is currently initialized to NULL for all |
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// collectors except for CMS and G1. |
1 | 240 |
BoolObjectClosure* _is_alive_non_header; |
241 |
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// Soft ref clearing policies |
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// . the default policy |
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static ReferencePolicy* _default_soft_ref_policy; |
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// . the "clear all" policy |
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static ReferencePolicy* _always_clear_soft_ref_policy; |
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// . the current policy below is either one of the above |
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ReferencePolicy* _current_soft_ref_policy; |
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249 |
|
1 | 250 |
// The discovered ref lists themselves |
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251 |
|
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// The active MT'ness degree of the queues below |
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int _num_q; |
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// The maximum MT'ness degree of the queues below |
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int _max_num_q; |
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// Arrays of lists of oops, one per thread |
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DiscoveredList* _discoveredSoftRefs; |
1 | 258 |
DiscoveredList* _discoveredWeakRefs; |
259 |
DiscoveredList* _discoveredFinalRefs; |
|
260 |
DiscoveredList* _discoveredPhantomRefs; |
|
261 |
||
262 |
public: |
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static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } |
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264 |
|
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int num_q() { return _num_q; } |
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int max_num_q() { return _max_num_q; } |
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void set_active_mt_degree(int v) { _num_q = v; } |
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DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
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269 |
|
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ReferencePolicy* setup_policy(bool always_clear) { |
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_current_soft_ref_policy = always_clear ? |
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_always_clear_soft_ref_policy : _default_soft_ref_policy; |
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_current_soft_ref_policy->setup(); // snapshot the policy threshold |
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return _current_soft_ref_policy; |
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275 |
} |
1 | 276 |
|
277 |
// Process references with a certain reachability level. |
|
278 |
void process_discovered_reflist(DiscoveredList refs_lists[], |
|
279 |
ReferencePolicy* policy, |
|
280 |
bool clear_referent, |
|
281 |
BoolObjectClosure* is_alive, |
|
282 |
OopClosure* keep_alive, |
|
283 |
VoidClosure* complete_gc, |
|
284 |
AbstractRefProcTaskExecutor* task_executor); |
|
285 |
||
286 |
void process_phaseJNI(BoolObjectClosure* is_alive, |
|
287 |
OopClosure* keep_alive, |
|
288 |
VoidClosure* complete_gc); |
|
289 |
||
290 |
// Work methods used by the method process_discovered_reflist |
|
291 |
// Phase1: keep alive all those referents that are otherwise |
|
292 |
// dead but which must be kept alive by policy (and their closure). |
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void process_phase1(DiscoveredList& refs_list, |
1 | 294 |
ReferencePolicy* policy, |
295 |
BoolObjectClosure* is_alive, |
|
296 |
OopClosure* keep_alive, |
|
297 |
VoidClosure* complete_gc); |
|
298 |
// Phase2: remove all those references whose referents are |
|
299 |
// reachable. |
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300 |
inline void process_phase2(DiscoveredList& refs_list, |
1 | 301 |
BoolObjectClosure* is_alive, |
302 |
OopClosure* keep_alive, |
|
303 |
VoidClosure* complete_gc) { |
|
304 |
if (discovery_is_atomic()) { |
|
305 |
// complete_gc is ignored in this case for this phase |
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pp2_work(refs_list, is_alive, keep_alive); |
1 | 307 |
} else { |
308 |
assert(complete_gc != NULL, "Error"); |
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309 |
pp2_work_concurrent_discovery(refs_list, is_alive, |
1 | 310 |
keep_alive, complete_gc); |
311 |
} |
|
312 |
} |
|
313 |
// Work methods in support of process_phase2 |
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void pp2_work(DiscoveredList& refs_list, |
1 | 315 |
BoolObjectClosure* is_alive, |
316 |
OopClosure* keep_alive); |
|
317 |
void pp2_work_concurrent_discovery( |
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DiscoveredList& refs_list, |
1 | 319 |
BoolObjectClosure* is_alive, |
320 |
OopClosure* keep_alive, |
|
321 |
VoidClosure* complete_gc); |
|
322 |
// Phase3: process the referents by either clearing them |
|
323 |
// or keeping them alive (and their closure) |
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324 |
void process_phase3(DiscoveredList& refs_list, |
1 | 325 |
bool clear_referent, |
326 |
BoolObjectClosure* is_alive, |
|
327 |
OopClosure* keep_alive, |
|
328 |
VoidClosure* complete_gc); |
|
329 |
||
330 |
// Enqueue references with a certain reachability level |
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331 |
void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
1 | 332 |
|
333 |
// "Preclean" all the discovered reference lists |
|
334 |
// by removing references with strongly reachable referents. |
|
335 |
// The first argument is a predicate on an oop that indicates |
|
336 |
// its (strong) reachability and the second is a closure that |
|
337 |
// may be used to incrementalize or abort the precleaning process. |
|
338 |
// The caller is responsible for taking care of potential |
|
339 |
// interference with concurrent operations on these lists |
|
340 |
// (or predicates involved) by other threads. Currently |
|
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|
341 |
// only used by the CMS collector. should_unload_classes is |
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|
342 |
// used to aid assertion checking when classes are collected. |
1 | 343 |
void preclean_discovered_references(BoolObjectClosure* is_alive, |
344 |
OopClosure* keep_alive, |
|
345 |
VoidClosure* complete_gc, |
|
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|
346 |
YieldClosure* yield, |
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|
347 |
bool should_unload_classes); |
1 | 348 |
|
349 |
// Delete entries in the discovered lists that have |
|
350 |
// either a null referent or are not active. Such |
|
351 |
// Reference objects can result from the clearing |
|
352 |
// or enqueueing of Reference objects concurrent |
|
353 |
// with their discovery by a (concurrent) collector. |
|
354 |
// For a definition of "active" see java.lang.ref.Reference; |
|
355 |
// Refs are born active, become inactive when enqueued, |
|
356 |
// and never become active again. The state of being |
|
357 |
// active is encoded as follows: A Ref is active |
|
358 |
// if and only if its "next" field is NULL. |
|
359 |
void clean_up_discovered_references(); |
|
360 |
void clean_up_discovered_reflist(DiscoveredList& refs_list); |
|
361 |
||
362 |
// Returns the name of the discovered reference list |
|
363 |
// occupying the i / _num_q slot. |
|
364 |
const char* list_name(int i); |
|
365 |
||
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|
366 |
void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
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|
367 |
|
1 | 368 |
protected: |
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|
369 |
// Set the 'discovered' field of the given reference to |
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|
370 |
// the given value - emitting barriers depending upon |
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|
371 |
// the value of _discovered_list_needs_barrier. |
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|
372 |
void set_discovered(oop ref, oop value); |
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|
373 |
|
1 | 374 |
// "Preclean" the given discovered reference list |
375 |
// by removing references with strongly reachable referents. |
|
376 |
// Currently used in support of CMS only. |
|
377 |
void preclean_discovered_reflist(DiscoveredList& refs_list, |
|
378 |
BoolObjectClosure* is_alive, |
|
379 |
OopClosure* keep_alive, |
|
380 |
VoidClosure* complete_gc, |
|
381 |
YieldClosure* yield); |
|
382 |
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|
383 |
// round-robin mod _num_q (not: _not_ mode _max_num_q) |
1 | 384 |
int next_id() { |
385 |
int id = _next_id; |
|
386 |
if (++_next_id == _num_q) { |
|
387 |
_next_id = 0; |
|
388 |
} |
|
389 |
return id; |
|
390 |
} |
|
391 |
DiscoveredList* get_discovered_list(ReferenceType rt); |
|
392 |
inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, |
|
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|
393 |
HeapWord* discovered_addr); |
1 | 394 |
void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
395 |
||
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|
396 |
void clear_discovered_references(DiscoveredList& refs_list); |
1 | 397 |
void abandon_partial_discovered_list(DiscoveredList& refs_list); |
398 |
||
399 |
// Calculate the number of jni handles. |
|
400 |
unsigned int count_jni_refs(); |
|
401 |
||
402 |
// Balances reference queues. |
|
403 |
void balance_queues(DiscoveredList ref_lists[]); |
|
404 |
||
405 |
// Update (advance) the soft ref master clock field. |
|
406 |
void update_soft_ref_master_clock(); |
|
407 |
||
408 |
public: |
|
409 |
// constructor |
|
410 |
ReferenceProcessor(): |
|
411 |
_span((HeapWord*)NULL, (HeapWord*)NULL), |
|
412 |
_discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), |
|
413 |
_discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), |
|
414 |
_discovering_refs(false), |
|
415 |
_discovery_is_atomic(true), |
|
416 |
_enqueuing_is_done(false), |
|
417 |
_discovery_is_mt(false), |
|
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|
418 |
_discovered_list_needs_barrier(false), |
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|
419 |
_bs(NULL), |
1 | 420 |
_is_alive_non_header(NULL), |
421 |
_num_q(0), |
|
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|
422 |
_max_num_q(0), |
1 | 423 |
_processing_is_mt(false), |
424 |
_next_id(0) |
|
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|
425 |
{ } |
1 | 426 |
|
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|
427 |
// Default parameters give you a vanilla reference processor. |
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|
428 |
ReferenceProcessor(MemRegion span, |
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|
429 |
bool mt_processing = false, int mt_processing_degree = 1, |
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|
430 |
bool mt_discovery = false, int mt_discovery_degree = 1, |
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|
431 |
bool atomic_discovery = true, |
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|
432 |
BoolObjectClosure* is_alive_non_header = NULL, |
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|
433 |
bool discovered_list_needs_barrier = false); |
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|
434 |
|
1 | 435 |
// RefDiscoveryPolicy values |
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|
436 |
enum DiscoveryPolicy { |
1 | 437 |
ReferenceBasedDiscovery = 0, |
4885
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|
438 |
ReferentBasedDiscovery = 1, |
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|
439 |
DiscoveryPolicyMin = ReferenceBasedDiscovery, |
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|
440 |
DiscoveryPolicyMax = ReferentBasedDiscovery |
1 | 441 |
}; |
442 |
||
443 |
static void init_statics(); |
|
444 |
||
445 |
public: |
|
446 |
// get and set "is_alive_non_header" field |
|
447 |
BoolObjectClosure* is_alive_non_header() { |
|
448 |
return _is_alive_non_header; |
|
449 |
} |
|
450 |
void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { |
|
451 |
_is_alive_non_header = is_alive_non_header; |
|
452 |
} |
|
453 |
||
454 |
// get and set span |
|
455 |
MemRegion span() { return _span; } |
|
456 |
void set_span(MemRegion span) { _span = span; } |
|
457 |
||
458 |
// start and stop weak ref discovery |
|
10670
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|
459 |
void enable_discovery(bool verify_disabled, bool check_no_refs) { |
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|
460 |
#ifdef ASSERT |
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|
461 |
// Verify that we're not currently discovering refs |
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|
462 |
assert(!verify_disabled || !_discovering_refs, "nested call?"); |
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|
463 |
|
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|
464 |
if (check_no_refs) { |
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|
465 |
// Verify that the discovered lists are empty |
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|
466 |
verify_no_references_recorded(); |
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|
467 |
} |
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|
468 |
#endif // ASSERT |
4ea0e7d2ffbc
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|
469 |
_discovering_refs = true; |
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|
470 |
} |
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|
471 |
|
1 | 472 |
void disable_discovery() { _discovering_refs = false; } |
473 |
bool discovery_enabled() { return _discovering_refs; } |
|
474 |
||
475 |
// whether discovery is atomic wrt other collectors |
|
476 |
bool discovery_is_atomic() const { return _discovery_is_atomic; } |
|
477 |
void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } |
|
478 |
||
10526
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|
479 |
// whether the JDK in which we are embedded is a pre-4965777 JDK, |
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|
480 |
// and thus whether or not it uses the discovered field to chain |
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|
481 |
// the entries in the pending list. |
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|
482 |
static bool pending_list_uses_discovered_field() { |
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|
483 |
return _pending_list_uses_discovered_field; |
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|
484 |
} |
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|
485 |
|
1 | 486 |
// whether discovery is done by multiple threads same-old-timeously |
487 |
bool discovery_is_mt() const { return _discovery_is_mt; } |
|
488 |
void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } |
|
489 |
||
490 |
// Whether we are in a phase when _processing_ is MT. |
|
491 |
bool processing_is_mt() const { return _processing_is_mt; } |
|
492 |
void set_mt_processing(bool mt) { _processing_is_mt = mt; } |
|
493 |
||
494 |
// whether all enqueuing of weak references is complete |
|
495 |
bool enqueuing_is_done() { return _enqueuing_is_done; } |
|
496 |
void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } |
|
497 |
||
498 |
// iterate over oops |
|
499 |
void weak_oops_do(OopClosure* f); // weak roots |
|
500 |
||
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|
501 |
// Balance each of the discovered lists. |
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|
502 |
void balance_all_queues(); |
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|
503 |
|
1 | 504 |
// Discover a Reference object, using appropriate discovery criteria |
505 |
bool discover_reference(oop obj, ReferenceType rt); |
|
506 |
||
507 |
// Process references found during GC (called by the garbage collector) |
|
1606
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|
508 |
void process_discovered_references(BoolObjectClosure* is_alive, |
1 | 509 |
OopClosure* keep_alive, |
510 |
VoidClosure* complete_gc, |
|
511 |
AbstractRefProcTaskExecutor* task_executor); |
|
512 |
||
513 |
public: |
|
514 |
// Enqueue references at end of GC (called by the garbage collector) |
|
515 |
bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); |
|
516 |
||
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|
517 |
// If a discovery is in process that is being superceded, abandon it: all |
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|
518 |
// the discovered lists will be empty, and all the objects on them will |
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|
519 |
// have NULL discovered fields. Must be called only at a safepoint. |
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|
520 |
void abandon_partial_discovery(); |
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|
521 |
|
1 | 522 |
// debugging |
523 |
void verify_no_references_recorded() PRODUCT_RETURN; |
|
7420
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|
524 |
void verify_referent(oop obj) PRODUCT_RETURN; |
1 | 525 |
|
526 |
// clear the discovered lists (unlinking each entry). |
|
527 |
void clear_discovered_references() PRODUCT_RETURN; |
|
528 |
}; |
|
529 |
||
530 |
// A utility class to disable reference discovery in |
|
531 |
// the scope which contains it, for given ReferenceProcessor. |
|
532 |
class NoRefDiscovery: StackObj { |
|
533 |
private: |
|
534 |
ReferenceProcessor* _rp; |
|
535 |
bool _was_discovering_refs; |
|
536 |
public: |
|
537 |
NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { |
|
6459
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|
538 |
_was_discovering_refs = _rp->discovery_enabled(); |
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|
539 |
if (_was_discovering_refs) { |
1 | 540 |
_rp->disable_discovery(); |
541 |
} |
|
542 |
} |
|
543 |
||
544 |
~NoRefDiscovery() { |
|
545 |
if (_was_discovering_refs) { |
|
10670
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|
546 |
_rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); |
1 | 547 |
} |
548 |
} |
|
549 |
}; |
|
550 |
||
551 |
||
552 |
// A utility class to temporarily mutate the span of the |
|
553 |
// given ReferenceProcessor in the scope that contains it. |
|
554 |
class ReferenceProcessorSpanMutator: StackObj { |
|
555 |
private: |
|
556 |
ReferenceProcessor* _rp; |
|
557 |
MemRegion _saved_span; |
|
558 |
||
559 |
public: |
|
560 |
ReferenceProcessorSpanMutator(ReferenceProcessor* rp, |
|
561 |
MemRegion span): |
|
562 |
_rp(rp) { |
|
563 |
_saved_span = _rp->span(); |
|
564 |
_rp->set_span(span); |
|
565 |
} |
|
566 |
||
567 |
~ReferenceProcessorSpanMutator() { |
|
568 |
_rp->set_span(_saved_span); |
|
569 |
} |
|
570 |
}; |
|
571 |
||
572 |
// A utility class to temporarily change the MT'ness of |
|
573 |
// reference discovery for the given ReferenceProcessor |
|
574 |
// in the scope that contains it. |
|
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|
575 |
class ReferenceProcessorMTDiscoveryMutator: StackObj { |
1 | 576 |
private: |
577 |
ReferenceProcessor* _rp; |
|
578 |
bool _saved_mt; |
|
579 |
||
580 |
public: |
|
8688
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|
581 |
ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
493d12ccc6db
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|
582 |
bool mt): |
1 | 583 |
_rp(rp) { |
584 |
_saved_mt = _rp->discovery_is_mt(); |
|
585 |
_rp->set_mt_discovery(mt); |
|
586 |
} |
|
587 |
||
8688
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|
588 |
~ReferenceProcessorMTDiscoveryMutator() { |
1 | 589 |
_rp->set_mt_discovery(_saved_mt); |
590 |
} |
|
591 |
}; |
|
592 |
||
593 |
||
594 |
// A utility class to temporarily change the disposition |
|
595 |
// of the "is_alive_non_header" closure field of the |
|
596 |
// given ReferenceProcessor in the scope that contains it. |
|
597 |
class ReferenceProcessorIsAliveMutator: StackObj { |
|
598 |
private: |
|
599 |
ReferenceProcessor* _rp; |
|
600 |
BoolObjectClosure* _saved_cl; |
|
601 |
||
602 |
public: |
|
603 |
ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, |
|
604 |
BoolObjectClosure* cl): |
|
605 |
_rp(rp) { |
|
606 |
_saved_cl = _rp->is_alive_non_header(); |
|
607 |
_rp->set_is_alive_non_header(cl); |
|
608 |
} |
|
609 |
||
610 |
~ReferenceProcessorIsAliveMutator() { |
|
611 |
_rp->set_is_alive_non_header(_saved_cl); |
|
612 |
} |
|
613 |
}; |
|
614 |
||
615 |
// A utility class to temporarily change the disposition |
|
616 |
// of the "discovery_is_atomic" field of the |
|
617 |
// given ReferenceProcessor in the scope that contains it. |
|
618 |
class ReferenceProcessorAtomicMutator: StackObj { |
|
619 |
private: |
|
620 |
ReferenceProcessor* _rp; |
|
621 |
bool _saved_atomic_discovery; |
|
622 |
||
623 |
public: |
|
624 |
ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, |
|
625 |
bool atomic): |
|
626 |
_rp(rp) { |
|
627 |
_saved_atomic_discovery = _rp->discovery_is_atomic(); |
|
628 |
_rp->set_atomic_discovery(atomic); |
|
629 |
} |
|
630 |
||
631 |
~ReferenceProcessorAtomicMutator() { |
|
632 |
_rp->set_atomic_discovery(_saved_atomic_discovery); |
|
633 |
} |
|
634 |
}; |
|
635 |
||
636 |
||
637 |
// A utility class to temporarily change the MT processing |
|
638 |
// disposition of the given ReferenceProcessor instance |
|
639 |
// in the scope that contains it. |
|
640 |
class ReferenceProcessorMTProcMutator: StackObj { |
|
641 |
private: |
|
642 |
ReferenceProcessor* _rp; |
|
643 |
bool _saved_mt; |
|
644 |
||
645 |
public: |
|
646 |
ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, |
|
647 |
bool mt): |
|
648 |
_rp(rp) { |
|
649 |
_saved_mt = _rp->processing_is_mt(); |
|
650 |
_rp->set_mt_processing(mt); |
|
651 |
} |
|
652 |
||
653 |
~ReferenceProcessorMTProcMutator() { |
|
654 |
_rp->set_mt_processing(_saved_mt); |
|
655 |
} |
|
656 |
}; |
|
657 |
||
658 |
||
659 |
// This class is an interface used to implement task execution for the |
|
660 |
// reference processing. |
|
661 |
class AbstractRefProcTaskExecutor { |
|
662 |
public: |
|
663 |
||
664 |
// Abstract tasks to execute. |
|
665 |
class ProcessTask; |
|
666 |
class EnqueueTask; |
|
667 |
||
668 |
// Executes a task using worker threads. |
|
669 |
virtual void execute(ProcessTask& task) = 0; |
|
670 |
virtual void execute(EnqueueTask& task) = 0; |
|
671 |
||
672 |
// Switch to single threaded mode. |
|
673 |
virtual void set_single_threaded_mode() { }; |
|
674 |
}; |
|
675 |
||
676 |
// Abstract reference processing task to execute. |
|
677 |
class AbstractRefProcTaskExecutor::ProcessTask { |
|
678 |
protected: |
|
679 |
ProcessTask(ReferenceProcessor& ref_processor, |
|
680 |
DiscoveredList refs_lists[], |
|
681 |
bool marks_oops_alive) |
|
682 |
: _ref_processor(ref_processor), |
|
683 |
_refs_lists(refs_lists), |
|
684 |
_marks_oops_alive(marks_oops_alive) |
|
685 |
{ } |
|
686 |
||
687 |
public: |
|
688 |
virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, |
|
689 |
OopClosure& keep_alive, |
|
690 |
VoidClosure& complete_gc) = 0; |
|
691 |
||
692 |
// Returns true if a task marks some oops as alive. |
|
693 |
bool marks_oops_alive() const |
|
694 |
{ return _marks_oops_alive; } |
|
695 |
||
696 |
protected: |
|
697 |
ReferenceProcessor& _ref_processor; |
|
698 |
DiscoveredList* _refs_lists; |
|
699 |
const bool _marks_oops_alive; |
|
700 |
}; |
|
701 |
||
702 |
// Abstract reference processing task to execute. |
|
703 |
class AbstractRefProcTaskExecutor::EnqueueTask { |
|
704 |
protected: |
|
705 |
EnqueueTask(ReferenceProcessor& ref_processor, |
|
706 |
DiscoveredList refs_lists[], |
|
360
21d113ecbf6a
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
1
diff
changeset
|
707 |
HeapWord* pending_list_addr, |
1 | 708 |
int n_queues) |
709 |
: _ref_processor(ref_processor), |
|
710 |
_refs_lists(refs_lists), |
|
711 |
_pending_list_addr(pending_list_addr), |
|
712 |
_n_queues(n_queues) |
|
713 |
{ } |
|
714 |
||
715 |
public: |
|
716 |
virtual void work(unsigned int work_id) = 0; |
|
717 |
||
718 |
protected: |
|
719 |
ReferenceProcessor& _ref_processor; |
|
720 |
DiscoveredList* _refs_lists; |
|
360
21d113ecbf6a
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
1
diff
changeset
|
721 |
HeapWord* _pending_list_addr; |
1 | 722 |
int _n_queues; |
723 |
}; |
|
7397 | 724 |
|
725 |
#endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |