Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp @ 7469:0c8717a92b2d
8001341: SIGSEGV in methodOopDesc::fast_exception_handler_bci_for(KlassHandle,int,Thread*)+0x3e9.
Summary: Use methodHandle.
Reviewed-by: coleenp, acorn, twisti, sspitsyn
author | jiangli |
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date | Tue, 08 Jan 2013 13:01:19 -0500 |
parents | 3a431b605145 |
children | 194f52aa2f23 |
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/* * Copyright (c) 2001, 2012, 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/concurrentG1Refine.hpp" #include "gc_implementation/g1/concurrentG1RefineThread.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/g1CollectorPolicy.hpp" #include "gc_implementation/g1/g1GCPhaseTimes.hpp" #include "gc_implementation/g1/g1RemSet.hpp" #include "gc_implementation/g1/heapRegionSeq.inline.hpp" #include "memory/space.inline.hpp" #include "runtime/atomic.hpp" #include "runtime/java.hpp" #include "utilities/copy.hpp" // Possible sizes for the card counts cache: odd primes that roughly double in size. // (See jvmtiTagMap.cpp). #define MAX_SIZE ((size_t) -1) size_t ConcurrentG1Refine::_cc_cache_sizes[] = { 16381, 32771, 76831, 150001, 307261, 614563, 1228891, 2457733, 4915219, 9830479, 19660831, 39321619, 78643219, 157286461, MAX_SIZE }; ConcurrentG1Refine::ConcurrentG1Refine() : _card_counts(NULL), _card_epochs(NULL), _n_card_counts(0), _max_cards(0), _max_n_card_counts(0), _cache_size_index(0), _expand_card_counts(false), _hot_cache(NULL), _def_use_cache(false), _use_cache(false), // We initialize the epochs of the array to 0. By initializing // _n_periods to 1 and not 0 we automatically invalidate all the // entries on the array. Otherwise we might accidentally think that // we claimed a card that was in fact never set (see CR7033292). _n_periods(1), _threads(NULL), _n_threads(0) { // Ergomonically select initial concurrent refinement parameters if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) { FLAG_SET_DEFAULT(G1ConcRefinementGreenZone, MAX2<int>(ParallelGCThreads, 1)); } set_green_zone(G1ConcRefinementGreenZone); if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) { FLAG_SET_DEFAULT(G1ConcRefinementYellowZone, green_zone() * 3); } set_yellow_zone(MAX2<int>(G1ConcRefinementYellowZone, green_zone())); if (FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) { FLAG_SET_DEFAULT(G1ConcRefinementRedZone, yellow_zone() * 2); } set_red_zone(MAX2<int>(G1ConcRefinementRedZone, yellow_zone())); _n_worker_threads = thread_num(); // We need one extra thread to do the young gen rset size sampling. _n_threads = _n_worker_threads + 1; reset_threshold_step(); _threads = NEW_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _n_threads, mtGC); int worker_id_offset = (int)DirtyCardQueueSet::num_par_ids(); ConcurrentG1RefineThread *next = NULL; for (int i = _n_threads - 1; i >= 0; i--) { ConcurrentG1RefineThread* t = new ConcurrentG1RefineThread(this, next, worker_id_offset, i); assert(t != NULL, "Conc refine should have been created"); assert(t->cg1r() == this, "Conc refine thread should refer to this"); _threads[i] = t; next = t; } } void ConcurrentG1Refine::reset_threshold_step() { if (FLAG_IS_DEFAULT(G1ConcRefinementThresholdStep)) { _thread_threshold_step = (yellow_zone() - green_zone()) / (worker_thread_num() + 1); } else { _thread_threshold_step = G1ConcRefinementThresholdStep; } } int ConcurrentG1Refine::thread_num() { return MAX2<int>((G1ConcRefinementThreads > 0) ? G1ConcRefinementThreads : ParallelGCThreads, 1); } void ConcurrentG1Refine::init() { if (G1ConcRSLogCacheSize > 0) { _g1h = G1CollectedHeap::heap(); _max_cards = _g1h->max_capacity() >> CardTableModRefBS::card_shift; _max_n_card_counts = _max_cards * G1MaxHotCardCountSizePercent / 100; size_t max_card_num = ((size_t)1 << (sizeof(unsigned)*BitsPerByte-1)) - 1; guarantee(_max_cards < max_card_num, "card_num representation"); // We need _n_card_counts to be less than _max_n_card_counts here // so that the expansion call (below) actually allocates the // _counts and _epochs arrays. assert(_n_card_counts == 0, "pre-condition"); assert(_max_n_card_counts > 0, "pre-condition"); // Find the index into cache size array that is of a size that's // large enough to hold desired_sz. size_t desired_sz = _max_cards / InitialCacheFraction; int desired_sz_index = 0; while (_cc_cache_sizes[desired_sz_index] < desired_sz) { desired_sz_index += 1; assert(desired_sz_index < MAX_CC_CACHE_INDEX, "invariant"); } assert(desired_sz_index < MAX_CC_CACHE_INDEX, "invariant"); // If the desired_sz value is between two sizes then // _cc_cache_sizes[desired_sz_index-1] < desired_sz <= _cc_cache_sizes[desired_sz_index] // we will start with the lower size in the optimistic expectation that // we will not need to expand up. Note desired_sz_index could also be 0. if (desired_sz_index > 0 && _cc_cache_sizes[desired_sz_index] > desired_sz) { desired_sz_index -= 1; } if (!expand_card_count_cache(desired_sz_index)) { // Allocation was unsuccessful - exit vm_exit_during_initialization("Could not reserve enough space for card count cache"); } assert(_n_card_counts > 0, "post-condition"); assert(_cache_size_index == desired_sz_index, "post-condition"); Copy::fill_to_bytes(&_card_counts[0], _n_card_counts * sizeof(CardCountCacheEntry)); Copy::fill_to_bytes(&_card_epochs[0], _n_card_counts * sizeof(CardEpochCacheEntry)); ModRefBarrierSet* bs = _g1h->mr_bs(); guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition"); _ct_bs = (CardTableModRefBS*)bs; _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start()); _def_use_cache = true; _use_cache = true; _hot_cache_size = (1 << G1ConcRSLogCacheSize); _hot_cache = NEW_C_HEAP_ARRAY(jbyte*, _hot_cache_size, mtGC); _n_hot = 0; _hot_cache_idx = 0; // For refining the cards in the hot cache in parallel int n_workers = (ParallelGCThreads > 0 ? _g1h->workers()->total_workers() : 1); _hot_cache_par_chunk_size = MAX2(1, _hot_cache_size / n_workers); _hot_cache_par_claimed_idx = 0; } } void ConcurrentG1Refine::stop() { if (_threads != NULL) { for (int i = 0; i < _n_threads; i++) { _threads[i]->stop(); } } } void ConcurrentG1Refine::reinitialize_threads() { reset_threshold_step(); if (_threads != NULL) { for (int i = 0; i < _n_threads; i++) { _threads[i]->initialize(); } } } ConcurrentG1Refine::~ConcurrentG1Refine() { if (G1ConcRSLogCacheSize > 0) { // Please see the comment in allocate_card_count_cache // for why we call os::malloc() and os::free() directly. assert(_card_counts != NULL, "Logic"); os::free(_card_counts, mtGC); assert(_card_epochs != NULL, "Logic"); os::free(_card_epochs, mtGC); assert(_hot_cache != NULL, "Logic"); FREE_C_HEAP_ARRAY(jbyte*, _hot_cache, mtGC); } if (_threads != NULL) { for (int i = 0; i < _n_threads; i++) { delete _threads[i]; } FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads, mtGC); } } void ConcurrentG1Refine::threads_do(ThreadClosure *tc) { if (_threads != NULL) { for (int i = 0; i < _n_threads; i++) { tc->do_thread(_threads[i]); } } } bool ConcurrentG1Refine::is_young_card(jbyte* card_ptr) { HeapWord* start = _ct_bs->addr_for(card_ptr); HeapRegion* r = _g1h->heap_region_containing(start); if (r != NULL && r->is_young()) { return true; } // This card is not associated with a heap region // so can't be young. return false; } jbyte* ConcurrentG1Refine::add_card_count(jbyte* card_ptr, int* count, bool* defer) { unsigned new_card_num = ptr_2_card_num(card_ptr); unsigned bucket = hash(new_card_num); assert(0 <= bucket && bucket < _n_card_counts, "Bounds"); CardCountCacheEntry* count_ptr = &_card_counts[bucket]; CardEpochCacheEntry* epoch_ptr = &_card_epochs[bucket]; // We have to construct a new entry if we haven't updated the counts // during the current period, or if the count was updated for a // different card number. unsigned int new_epoch = (unsigned int) _n_periods; julong new_epoch_entry = make_epoch_entry(new_card_num, new_epoch); while (true) { // Fetch the previous epoch value julong prev_epoch_entry = epoch_ptr->_value; julong cas_res; if (extract_epoch(prev_epoch_entry) != new_epoch) { // This entry has not yet been updated during this period. // Note: we update the epoch value atomically to ensure // that there is only one winner that updates the cached // card_ptr value even though all the refine threads share // the same epoch value. cas_res = (julong) Atomic::cmpxchg((jlong) new_epoch_entry, (volatile jlong*)&epoch_ptr->_value, (jlong) prev_epoch_entry); if (cas_res == prev_epoch_entry) { // We have successfully won the race to update the // epoch and card_num value. Make it look like the // count and eviction count were previously cleared. count_ptr->_count = 1; count_ptr->_evict_count = 0; *count = 0; // We can defer the processing of card_ptr *defer = true; return card_ptr; } // We did not win the race to update the epoch field, so some other // thread must have done it. The value that gets returned by CAS // should be the new epoch value. assert(extract_epoch(cas_res) == new_epoch, "unexpected epoch"); // We could 'continue' here or just re-read the previous epoch value prev_epoch_entry = epoch_ptr->_value; } // The epoch entry for card_ptr has been updated during this period. unsigned old_card_num = extract_card_num(prev_epoch_entry); // The card count that will be returned to caller *count = count_ptr->_count; // Are we updating the count for the same card? if (new_card_num == old_card_num) { // Same card - just update the count. We could have more than one // thread racing to update count for the current card. It should be // OK not to use a CAS as the only penalty should be some missed // increments of the count which delays identifying the card as "hot". if (*count < max_jubyte) count_ptr->_count++; // We can defer the processing of card_ptr *defer = true; return card_ptr; } // Different card - evict old card info if (count_ptr->_evict_count < max_jubyte) count_ptr->_evict_count++; if (count_ptr->_evict_count > G1CardCountCacheExpandThreshold) { // Trigger a resize the next time we clear _expand_card_counts = true; } cas_res = (julong) Atomic::cmpxchg((jlong) new_epoch_entry, (volatile jlong*)&epoch_ptr->_value, (jlong) prev_epoch_entry); if (cas_res == prev_epoch_entry) { // We successfully updated the card num value in the epoch entry count_ptr->_count = 0; // initialize counter for new card num jbyte* old_card_ptr = card_num_2_ptr(old_card_num); // Even though the region containg the card at old_card_num was not // in the young list when old_card_num was recorded in the epoch // cache it could have been added to the free list and subsequently // added to the young list in the intervening time. See CR 6817995. // We do not deal with this case here - it will be handled in // HeapRegion::oops_on_card_seq_iterate_careful after it has been // determined that the region containing the card has been allocated // to, and it's safe to check the young type of the region. // We do not want to defer processing of card_ptr in this case // (we need to refine old_card_ptr and card_ptr) *defer = false; return old_card_ptr; } // Someone else beat us - try again. } } jbyte* ConcurrentG1Refine::cache_insert(jbyte* card_ptr, bool* defer) { int count; jbyte* cached_ptr = add_card_count(card_ptr, &count, defer); assert(cached_ptr != NULL, "bad cached card ptr"); // We've just inserted a card pointer into the card count cache // and got back the card that we just inserted or (evicted) the // previous contents of that count slot. // The card we got back could be in a young region. When the // returned card (if evicted) was originally inserted, we had // determined that its containing region was not young. However // it is possible for the region to be freed during a cleanup // pause, then reallocated and tagged as young which will result // in the returned card residing in a young region. // // We do not deal with this case here - the change from non-young // to young could be observed at any time - it will be handled in // HeapRegion::oops_on_card_seq_iterate_careful after it has been // determined that the region containing the card has been allocated // to. // The card pointer we obtained from card count cache is not hot // so do not store it in the cache; return it for immediate // refining. if (count < G1ConcRSHotCardLimit) { return cached_ptr; } // Otherwise, the pointer we got from the _card_counts cache is hot. jbyte* res = NULL; MutexLockerEx x(HotCardCache_lock, Mutex::_no_safepoint_check_flag); if (_n_hot == _hot_cache_size) { res = _hot_cache[_hot_cache_idx]; _n_hot--; } // Now _n_hot < _hot_cache_size, and we can insert at _hot_cache_idx. _hot_cache[_hot_cache_idx] = cached_ptr; _hot_cache_idx++; if (_hot_cache_idx == _hot_cache_size) _hot_cache_idx = 0; _n_hot++; // The card obtained from the hot card cache could be in a young // region. See above on how this can happen. return res; } void ConcurrentG1Refine::clean_up_cache(int worker_i, G1RemSet* g1rs, DirtyCardQueue* into_cset_dcq) { assert(!use_cache(), "cache should be disabled"); int start_idx; while ((start_idx = _hot_cache_par_claimed_idx) < _n_hot) { // read once int end_idx = start_idx + _hot_cache_par_chunk_size; if (start_idx == Atomic::cmpxchg(end_idx, &_hot_cache_par_claimed_idx, start_idx)) { // The current worker has successfully claimed the chunk [start_idx..end_idx) end_idx = MIN2(end_idx, _n_hot); for (int i = start_idx; i < end_idx; i++) { jbyte* entry = _hot_cache[i]; if (entry != NULL) { if (g1rs->concurrentRefineOneCard(entry, worker_i, true)) { // 'entry' contains references that point into the current // collection set. We need to record 'entry' in the DCQS // that's used for that purpose. // // The only time we care about recording cards that contain // references that point into the collection set is during // RSet updating while within an evacuation pause. // In this case worker_i should be the id of a GC worker thread assert(SafepointSynchronize::is_at_safepoint(), "not during an evacuation pause"); assert(worker_i < (int) (ParallelGCThreads == 0 ? 1 : ParallelGCThreads), "incorrect worker id"); into_cset_dcq->enqueue(entry); } } } } } } // The arrays used to hold the card counts and the epochs must have // a 1:1 correspondence. Hence they are allocated and freed together // Returns true if the allocations of both the counts and epochs // were successful; false otherwise. bool ConcurrentG1Refine::allocate_card_count_cache(size_t n, CardCountCacheEntry** counts, CardEpochCacheEntry** epochs) { // We call the allocation/free routines directly for the counts // and epochs arrays. The NEW_C_HEAP_ARRAY/FREE_C_HEAP_ARRAY // macros call AllocateHeap and FreeHeap respectively. // AllocateHeap will call vm_exit_out_of_memory in the event // of an allocation failure and abort the JVM. With the // _counts/epochs arrays we only need to abort the JVM if the // initial allocation of these arrays fails. // // Additionally AllocateHeap/FreeHeap do some tracing of // allocate/free calls so calling one without calling the // other can cause inconsistencies in the tracing. So we // call neither. assert(*counts == NULL, "out param"); assert(*epochs == NULL, "out param"); size_t counts_size = n * sizeof(CardCountCacheEntry); size_t epochs_size = n * sizeof(CardEpochCacheEntry); *counts = (CardCountCacheEntry*) os::malloc(counts_size, mtGC); if (*counts == NULL) { // allocation was unsuccessful return false; } *epochs = (CardEpochCacheEntry*) os::malloc(epochs_size, mtGC); if (*epochs == NULL) { // allocation was unsuccessful - free counts array assert(*counts != NULL, "must be"); os::free(*counts, mtGC); *counts = NULL; return false; } // We successfully allocated both counts and epochs return true; } // Returns true if the card counts/epochs cache was // successfully expanded; false otherwise. bool ConcurrentG1Refine::expand_card_count_cache(int cache_size_idx) { // Can we expand the card count and epoch tables? if (_n_card_counts < _max_n_card_counts) { assert(cache_size_idx >= 0 && cache_size_idx < MAX_CC_CACHE_INDEX, "oob"); size_t cache_size = _cc_cache_sizes[cache_size_idx]; // Make sure we don't go bigger than we will ever need cache_size = MIN2(cache_size, _max_n_card_counts); // Should we expand the card count and card epoch tables? if (cache_size > _n_card_counts) { // We have been asked to allocate new, larger, arrays for // the card counts and the epochs. Attempt the allocation // of both before we free the existing arrays in case // the allocation is unsuccessful... CardCountCacheEntry* counts = NULL; CardEpochCacheEntry* epochs = NULL; if (allocate_card_count_cache(cache_size, &counts, &epochs)) { // Allocation was successful. // We can just free the old arrays; we're // not interested in preserving the contents if (_card_counts != NULL) os::free(_card_counts, mtGC); if (_card_epochs != NULL) os::free(_card_epochs, mtGC); // Cache the size of the arrays and the index that got us there. _n_card_counts = cache_size; _cache_size_index = cache_size_idx; _card_counts = counts; _card_epochs = epochs; // We successfully allocated/expanded the caches. return true; } } } // We did not successfully expand the caches. return false; } void ConcurrentG1Refine::clear_and_record_card_counts() { if (G1ConcRSLogCacheSize == 0) { return; } double start = os::elapsedTime(); if (_expand_card_counts) { int new_idx = _cache_size_index + 1; if (expand_card_count_cache(new_idx)) { // Allocation was successful and _n_card_counts has // been updated to the new size. We only need to clear // the epochs so we don't read a bogus epoch value // when inserting a card into the hot card cache. Copy::fill_to_bytes(&_card_epochs[0], _n_card_counts * sizeof(CardEpochCacheEntry)); } _expand_card_counts = false; } int this_epoch = (int) _n_periods; assert((this_epoch+1) <= max_jint, "to many periods"); // Update epoch _n_periods++; double cc_clear_time_ms = (os::elapsedTime() - start) * 1000; _g1h->g1_policy()->phase_times()->record_cc_clear_time_ms(cc_clear_time_ms); } void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const { for (int i = 0; i < _n_threads; ++i) { _threads[i]->print_on(st); st->cr(); } }