Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/satbQueue.cpp @ 2874:d90bf514d647
Renamed packages.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 08 Jun 2011 08:59:54 +0200 |
parents | 7e37af9d69ef |
children | 4dfb2df418f2 |
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/* * Copyright (c) 2001, 2011, 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. * */ #include "precompiled.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/satbQueue.hpp" #include "memory/allocation.inline.hpp" #include "memory/sharedHeap.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/thread.hpp" // This method removes entries from an SATB buffer that will not be // useful to the concurrent marking threads. An entry is removed if it // satisfies one of the following conditions: // // * it points to an object outside the G1 heap (G1's concurrent // marking only visits objects inside the G1 heap), // * it points to an object that has been allocated since marking // started (according to SATB those objects do not need to be // visited during marking), or // * it points to an object that has already been marked (no need to // process it again). // // The rest of the entries will be retained and are compacted towards // the top of the buffer. If with this filtering we clear a large // enough chunk of the buffer we can re-use it (instead of enqueueing // it) and we can just allow the mutator to carry on executing. bool ObjPtrQueue::should_enqueue_buffer() { assert(_lock == NULL || _lock->owned_by_self(), "we should have taken the lock before calling this"); // A value of 0 means "don't filter SATB buffers". if (G1SATBBufferEnqueueingThresholdPercent == 0) { return true; } G1CollectedHeap* g1h = G1CollectedHeap::heap(); // This method should only be called if there is a non-NULL buffer // that is full. assert(_index == 0, "pre-condition"); assert(_buf != NULL, "pre-condition"); void** buf = _buf; size_t sz = _sz; // Used for sanity checking at the end of the loop. debug_only(size_t entries = 0; size_t retained = 0;) size_t i = sz; size_t new_index = sz; // Given that we are expecting _index == 0, we could have changed // the loop condition to (i > 0). But we are using _index for // generality. while (i > _index) { assert(i > 0, "we should have at least one more entry to process"); i -= oopSize; debug_only(entries += 1;) oop* p = (oop*) &buf[byte_index_to_index((int) i)]; oop obj = *p; // NULL the entry so that unused parts of the buffer contain NULLs // at the end. If we are going to retain it we will copy it to its // final place. If we have retained all entries we have visited so // far, we'll just end up copying it to the same place. *p = NULL; bool retain = g1h->is_obj_ill(obj); if (retain) { assert(new_index > 0, "we should not have already filled up the buffer"); new_index -= oopSize; assert(new_index >= i, "new_index should never be below i, as we alwaysr compact 'up'"); oop* new_p = (oop*) &buf[byte_index_to_index((int) new_index)]; assert(new_p >= p, "the destination location should never be below " "the source as we always compact 'up'"); assert(*new_p == NULL, "we should have already cleared the destination location"); *new_p = obj; debug_only(retained += 1;) } } size_t entries_calc = (sz - _index) / oopSize; assert(entries == entries_calc, "the number of entries we counted " "should match the number of entries we calculated"); size_t retained_calc = (sz - new_index) / oopSize; assert(retained == retained_calc, "the number of retained entries we counted " "should match the number of retained entries we calculated"); size_t perc = retained_calc * 100 / entries_calc; bool should_enqueue = perc > (size_t) G1SATBBufferEnqueueingThresholdPercent; _index = new_index; return should_enqueue; } void ObjPtrQueue::apply_closure(ObjectClosure* cl) { if (_buf != NULL) { apply_closure_to_buffer(cl, _buf, _index, _sz); _index = _sz; } } void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl, void** buf, size_t index, size_t sz) { if (cl == NULL) return; for (size_t i = index; i < sz; i += oopSize) { oop obj = (oop)buf[byte_index_to_index((int)i)]; // There can be NULL entries because of destructors. if (obj != NULL) { cl->do_object(obj); } } } #ifdef ASSERT void ObjPtrQueue::verify_oops_in_buffer() { if (_buf == NULL) return; for (size_t i = _index; i < _sz; i += oopSize) { oop obj = (oop)_buf[byte_index_to_index((int)i)]; assert(obj != NULL && obj->is_oop(true /* ignore mark word */), "Not an oop"); } } #endif #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away #pragma warning( disable:4355 ) // 'this' : used in base member initializer list #endif // _MSC_VER SATBMarkQueueSet::SATBMarkQueueSet() : PtrQueueSet(), _closure(NULL), _par_closures(NULL), _shared_satb_queue(this, true /*perm*/) {} void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock, int process_completed_threshold, Mutex* lock) { PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold, -1); _shared_satb_queue.set_lock(lock); if (ParallelGCThreads > 0) { _par_closures = NEW_C_HEAP_ARRAY(ObjectClosure*, ParallelGCThreads); } } void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) { DEBUG_ONLY(t->satb_mark_queue().verify_oops_in_buffer();) t->satb_mark_queue().handle_zero_index(); } #ifdef ASSERT void SATBMarkQueueSet::dump_active_values(JavaThread* first, bool expected_active) { gclog_or_tty->print_cr("SATB queue active values for Java Threads"); gclog_or_tty->print_cr(" SATB queue set: active is %s", (is_active()) ? "TRUE" : "FALSE"); gclog_or_tty->print_cr(" expected_active is %s", (expected_active) ? "TRUE" : "FALSE"); for (JavaThread* t = first; t; t = t->next()) { bool active = t->satb_mark_queue().is_active(); gclog_or_tty->print_cr(" thread %s, active is %s", t->name(), (active) ? "TRUE" : "FALSE"); } } #endif // ASSERT void SATBMarkQueueSet::set_active_all_threads(bool b, bool expected_active) { assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); JavaThread* first = Threads::first(); #ifdef ASSERT if (_all_active != expected_active) { dump_active_values(first, expected_active); // I leave this here as a guarantee, instead of an assert, so // that it will still be compiled in if we choose to uncomment // the #ifdef ASSERT in a product build. The whole block is // within an #ifdef ASSERT so the guarantee will not be compiled // in a product build anyway. guarantee(false, "SATB queue set has an unexpected active value"); } #endif // ASSERT _all_active = b; for (JavaThread* t = first; t; t = t->next()) { #ifdef ASSERT bool active = t->satb_mark_queue().is_active(); if (active != expected_active) { dump_active_values(first, expected_active); // I leave this here as a guarantee, instead of an assert, so // that it will still be compiled in if we choose to uncomment // the #ifdef ASSERT in a product build. The whole block is // within an #ifdef ASSERT so the guarantee will not be compiled // in a product build anyway. guarantee(false, "thread has an unexpected active value in its SATB queue"); } #endif // ASSERT t->satb_mark_queue().set_active(b); } } void SATBMarkQueueSet::set_closure(ObjectClosure* closure) { _closure = closure; } void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) { assert(ParallelGCThreads > 0 && _par_closures != NULL, "Precondition"); _par_closures[i] = par_closure; } void SATBMarkQueueSet::iterate_closure_all_threads() { for(JavaThread* t = Threads::first(); t; t = t->next()) { t->satb_mark_queue().apply_closure(_closure); } shared_satb_queue()->apply_closure(_closure); } void SATBMarkQueueSet::par_iterate_closure_all_threads(int worker) { SharedHeap* sh = SharedHeap::heap(); int parity = sh->strong_roots_parity(); for(JavaThread* t = Threads::first(); t; t = t->next()) { if (t->claim_oops_do(true, parity)) { t->satb_mark_queue().apply_closure(_par_closures[worker]); } } // We'll have worker 0 do this one. if (worker == 0) { shared_satb_queue()->apply_closure(_par_closures[0]); } } bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par, int worker) { BufferNode* nd = NULL; { MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); if (_completed_buffers_head != NULL) { nd = _completed_buffers_head; _completed_buffers_head = nd->next(); if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL; _n_completed_buffers--; if (_n_completed_buffers == 0) _process_completed = false; } } ObjectClosure* cl = (par ? _par_closures[worker] : _closure); if (nd != NULL) { void **buf = BufferNode::make_buffer_from_node(nd); ObjPtrQueue::apply_closure_to_buffer(cl, buf, 0, _sz); deallocate_buffer(buf); return true; } else { return false; } } void SATBMarkQueueSet::abandon_partial_marking() { BufferNode* buffers_to_delete = NULL; { MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); while (_completed_buffers_head != NULL) { BufferNode* nd = _completed_buffers_head; _completed_buffers_head = nd->next(); nd->set_next(buffers_to_delete); buffers_to_delete = nd; } _completed_buffers_tail = NULL; _n_completed_buffers = 0; DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked()); } while (buffers_to_delete != NULL) { BufferNode* nd = buffers_to_delete; buffers_to_delete = nd->next(); deallocate_buffer(BufferNode::make_buffer_from_node(nd)); } assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); // So we can safely manipulate these queues. for (JavaThread* t = Threads::first(); t; t = t->next()) { t->satb_mark_queue().reset(); } shared_satb_queue()->reset(); }