Mercurial > hg > truffle
view src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp @ 1311:2a1472c30599
4396719: Mark Sweep stack overflow on deeply nested Object arrays
Summary: Use an explicit stack for object arrays and process them in chunks.
Reviewed-by: iveresov, apetrusenko
author | jcoomes |
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date | Wed, 03 Mar 2010 14:48:26 -0800 |
parents | df6caf649ff7 |
children | c18cbe5936b8 |
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/* * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ // A BufferingOops closure tries to separate out the cost of finding roots // from the cost of applying closures to them. It maintains an array of // ref-containing locations. Until the array is full, applying the closure // to an oop* merely records that location in the array. Since this // closure app cost is small, an elapsed timer can approximately attribute // all of this cost to the cost of finding the roots. When the array fills // up, the wrapped closure is applied to all elements, keeping track of // this elapsed time of this process, and leaving the array empty. // The caller must be sure to call "done" to process any unprocessed // buffered entriess. class Generation; class HeapRegion; class BufferingOopClosure: public OopClosure { protected: enum PrivateConstants { BufferLength = 1024 }; StarTask _buffer[BufferLength]; StarTask* _buffer_top; StarTask* _buffer_curr; OopClosure* _oc; double _closure_app_seconds; void process_buffer () { double start = os::elapsedTime(); for (StarTask* curr = _buffer; curr < _buffer_curr; ++curr) { if (curr->is_narrow()) { assert(UseCompressedOops, "Error"); _oc->do_oop((narrowOop*)(*curr)); } else { _oc->do_oop((oop*)(*curr)); } } _buffer_curr = _buffer; _closure_app_seconds += (os::elapsedTime() - start); } template <class T> inline void do_oop_work(T* p) { if (_buffer_curr == _buffer_top) { process_buffer(); } StarTask new_ref(p); *_buffer_curr = new_ref; ++_buffer_curr; } public: virtual void do_oop(narrowOop* p) { do_oop_work(p); } virtual void do_oop(oop* p) { do_oop_work(p); } void done () { if (_buffer_curr > _buffer) { process_buffer(); } } double closure_app_seconds () { return _closure_app_seconds; } BufferingOopClosure (OopClosure *oc) : _oc(oc), _buffer_curr(_buffer), _buffer_top(_buffer + BufferLength), _closure_app_seconds(0.0) { } }; class BufferingOopsInGenClosure: public OopsInGenClosure { BufferingOopClosure _boc; OopsInGenClosure* _oc; protected: template <class T> inline void do_oop_work(T* p) { assert(generation()->is_in_reserved((void*)p), "Must be in!"); _boc.do_oop(p); } public: BufferingOopsInGenClosure(OopsInGenClosure *oc) : _boc(oc), _oc(oc) {} virtual void do_oop(narrowOop* p) { do_oop_work(p); } virtual void do_oop(oop* p) { do_oop_work(p); } void done() { _boc.done(); } double closure_app_seconds () { return _boc.closure_app_seconds(); } void set_generation(Generation* gen) { OopsInGenClosure::set_generation(gen); _oc->set_generation(gen); } void reset_generation() { // Make sure we finish the current work with the current generation. _boc.done(); OopsInGenClosure::reset_generation(); _oc->reset_generation(); } }; class BufferingOopsInHeapRegionClosure: public OopsInHeapRegionClosure { private: enum PrivateConstants { BufferLength = 1024 }; StarTask _buffer[BufferLength]; StarTask* _buffer_top; StarTask* _buffer_curr; HeapRegion* _hr_buffer[BufferLength]; HeapRegion** _hr_curr; OopsInHeapRegionClosure* _oc; double _closure_app_seconds; void process_buffer () { assert((_hr_curr - _hr_buffer) == (_buffer_curr - _buffer), "the two lengths should be the same"); double start = os::elapsedTime(); HeapRegion** hr_curr = _hr_buffer; HeapRegion* hr_prev = NULL; for (StarTask* curr = _buffer; curr < _buffer_curr; ++curr) { HeapRegion* region = *hr_curr; if (region != hr_prev) { _oc->set_region(region); hr_prev = region; } if (curr->is_narrow()) { assert(UseCompressedOops, "Error"); _oc->do_oop((narrowOop*)(*curr)); } else { _oc->do_oop((oop*)(*curr)); } ++hr_curr; } _buffer_curr = _buffer; _hr_curr = _hr_buffer; _closure_app_seconds += (os::elapsedTime() - start); } public: virtual void do_oop(narrowOop* p) { do_oop_work(p); } virtual void do_oop( oop* p) { do_oop_work(p); } template <class T> void do_oop_work(T* p) { if (_buffer_curr == _buffer_top) { assert(_hr_curr > _hr_buffer, "_hr_curr should be consistent with _buffer_curr"); process_buffer(); } StarTask new_ref(p); *_buffer_curr = new_ref; ++_buffer_curr; *_hr_curr = _from; ++_hr_curr; } void done () { if (_buffer_curr > _buffer) { assert(_hr_curr > _hr_buffer, "_hr_curr should be consistent with _buffer_curr"); process_buffer(); } } double closure_app_seconds () { return _closure_app_seconds; } BufferingOopsInHeapRegionClosure (OopsInHeapRegionClosure *oc) : _oc(oc), _buffer_curr(_buffer), _buffer_top(_buffer + BufferLength), _hr_curr(_hr_buffer), _closure_app_seconds(0.0) { } };