| /* |
| * Copyright (c) 2000, 2014, 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 "memory/allocation.inline.hpp" |
| #include "memory/cardTableModRefBS.hpp" |
| #include "memory/cardTableRS.hpp" |
| #include "memory/sharedHeap.hpp" |
| #include "memory/space.hpp" |
| #include "memory/space.inline.hpp" |
| #include "memory/universe.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/virtualspace.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/macros.hpp" |
| #ifdef COMPILER1 |
| #include "c1/c1_LIR.hpp" |
| #include "c1/c1_LIRGenerator.hpp" |
| #endif |
| |
| // This kind of "BarrierSet" allows a "CollectedHeap" to detect and |
| // enumerate ref fields that have been modified (since the last |
| // enumeration.) |
| |
| size_t CardTableModRefBS::compute_byte_map_size() |
| { |
| assert(_guard_index == cards_required(_whole_heap.word_size()) - 1, |
| "unitialized, check declaration order"); |
| assert(_page_size != 0, "unitialized, check declaration order"); |
| const size_t granularity = os::vm_allocation_granularity(); |
| return align_size_up(_guard_index + 1, MAX2(_page_size, granularity)); |
| } |
| |
| CardTableModRefBS::CardTableModRefBS(MemRegion whole_heap, |
| int max_covered_regions): |
| ModRefBarrierSet(max_covered_regions), |
| _whole_heap(whole_heap), |
| _guard_index(0), |
| _guard_region(), |
| _last_valid_index(0), |
| _page_size(os::vm_page_size()), |
| _byte_map_size(0), |
| _covered(NULL), |
| _committed(NULL), |
| _cur_covered_regions(0), |
| _byte_map(NULL), |
| byte_map_base(NULL), |
| // LNC functionality |
| _lowest_non_clean(NULL), |
| _lowest_non_clean_chunk_size(NULL), |
| _lowest_non_clean_base_chunk_index(NULL), |
| _last_LNC_resizing_collection(NULL) |
| { |
| _kind = BarrierSet::CardTableModRef; |
| |
| assert((uintptr_t(_whole_heap.start()) & (card_size - 1)) == 0, "heap must start at card boundary"); |
| assert((uintptr_t(_whole_heap.end()) & (card_size - 1)) == 0, "heap must end at card boundary"); |
| |
| assert(card_size <= 512, "card_size must be less than 512"); // why? |
| |
| _covered = new MemRegion[_max_covered_regions]; |
| if (_covered == NULL) { |
| vm_exit_during_initialization("Could not allocate card table covered region set."); |
| } |
| } |
| |
| void CardTableModRefBS::initialize() { |
| _guard_index = cards_required(_whole_heap.word_size()) - 1; |
| _last_valid_index = _guard_index - 1; |
| |
| _byte_map_size = compute_byte_map_size(); |
| |
| HeapWord* low_bound = _whole_heap.start(); |
| HeapWord* high_bound = _whole_heap.end(); |
| |
| _cur_covered_regions = 0; |
| _committed = new MemRegion[_max_covered_regions]; |
| if (_committed == NULL) { |
| vm_exit_during_initialization("Could not allocate card table committed region set."); |
| } |
| |
| const size_t rs_align = _page_size == (size_t) os::vm_page_size() ? 0 : |
| MAX2(_page_size, (size_t) os::vm_allocation_granularity()); |
| ReservedSpace heap_rs(_byte_map_size, rs_align, false); |
| |
| MemTracker::record_virtual_memory_type((address)heap_rs.base(), mtGC); |
| |
| os::trace_page_sizes("card table", _guard_index + 1, _guard_index + 1, |
| _page_size, heap_rs.base(), heap_rs.size()); |
| if (!heap_rs.is_reserved()) { |
| vm_exit_during_initialization("Could not reserve enough space for the " |
| "card marking array"); |
| } |
| |
| // The assember store_check code will do an unsigned shift of the oop, |
| // then add it to byte_map_base, i.e. |
| // |
| // _byte_map = byte_map_base + (uintptr_t(low_bound) >> card_shift) |
| _byte_map = (jbyte*) heap_rs.base(); |
| byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift); |
| assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map"); |
| assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map"); |
| |
| jbyte* guard_card = &_byte_map[_guard_index]; |
| uintptr_t guard_page = align_size_down((uintptr_t)guard_card, _page_size); |
| _guard_region = MemRegion((HeapWord*)guard_page, _page_size); |
| os::commit_memory_or_exit((char*)guard_page, _page_size, _page_size, |
| !ExecMem, "card table last card"); |
| *guard_card = last_card; |
| |
| _lowest_non_clean = |
| NEW_C_HEAP_ARRAY(CardArr, _max_covered_regions, mtGC); |
| _lowest_non_clean_chunk_size = |
| NEW_C_HEAP_ARRAY(size_t, _max_covered_regions, mtGC); |
| _lowest_non_clean_base_chunk_index = |
| NEW_C_HEAP_ARRAY(uintptr_t, _max_covered_regions, mtGC); |
| _last_LNC_resizing_collection = |
| NEW_C_HEAP_ARRAY(int, _max_covered_regions, mtGC); |
| if (_lowest_non_clean == NULL |
| || _lowest_non_clean_chunk_size == NULL |
| || _lowest_non_clean_base_chunk_index == NULL |
| || _last_LNC_resizing_collection == NULL) |
| vm_exit_during_initialization("couldn't allocate an LNC array."); |
| for (int i = 0; i < _max_covered_regions; i++) { |
| _lowest_non_clean[i] = NULL; |
| _lowest_non_clean_chunk_size[i] = 0; |
| _last_LNC_resizing_collection[i] = -1; |
| } |
| |
| if (TraceCardTableModRefBS) { |
| gclog_or_tty->print_cr("CardTableModRefBS::CardTableModRefBS: "); |
| gclog_or_tty->print_cr(" " |
| " &_byte_map[0]: " INTPTR_FORMAT |
| " &_byte_map[_last_valid_index]: " INTPTR_FORMAT, |
| p2i(&_byte_map[0]), |
| p2i(&_byte_map[_last_valid_index])); |
| gclog_or_tty->print_cr(" " |
| " byte_map_base: " INTPTR_FORMAT, |
| p2i(byte_map_base)); |
| } |
| } |
| |
| CardTableModRefBS::~CardTableModRefBS() { |
| if (_covered) { |
| delete[] _covered; |
| _covered = NULL; |
| } |
| if (_committed) { |
| delete[] _committed; |
| _committed = NULL; |
| } |
| if (_lowest_non_clean) { |
| FREE_C_HEAP_ARRAY(CardArr, _lowest_non_clean, mtGC); |
| _lowest_non_clean = NULL; |
| } |
| if (_lowest_non_clean_chunk_size) { |
| FREE_C_HEAP_ARRAY(size_t, _lowest_non_clean_chunk_size, mtGC); |
| _lowest_non_clean_chunk_size = NULL; |
| } |
| if (_lowest_non_clean_base_chunk_index) { |
| FREE_C_HEAP_ARRAY(uintptr_t, _lowest_non_clean_base_chunk_index, mtGC); |
| _lowest_non_clean_base_chunk_index = NULL; |
| } |
| if (_last_LNC_resizing_collection) { |
| FREE_C_HEAP_ARRAY(int, _last_LNC_resizing_collection, mtGC); |
| _last_LNC_resizing_collection = NULL; |
| } |
| } |
| |
| int CardTableModRefBS::find_covering_region_by_base(HeapWord* base) { |
| int i; |
| for (i = 0; i < _cur_covered_regions; i++) { |
| if (_covered[i].start() == base) return i; |
| if (_covered[i].start() > base) break; |
| } |
| // If we didn't find it, create a new one. |
| assert(_cur_covered_regions < _max_covered_regions, |
| "too many covered regions"); |
| // Move the ones above up, to maintain sorted order. |
| for (int j = _cur_covered_regions; j > i; j--) { |
| _covered[j] = _covered[j-1]; |
| _committed[j] = _committed[j-1]; |
| } |
| int res = i; |
| _cur_covered_regions++; |
| _covered[res].set_start(base); |
| _covered[res].set_word_size(0); |
| jbyte* ct_start = byte_for(base); |
| uintptr_t ct_start_aligned = align_size_down((uintptr_t)ct_start, _page_size); |
| _committed[res].set_start((HeapWord*)ct_start_aligned); |
| _committed[res].set_word_size(0); |
| return res; |
| } |
| |
| int CardTableModRefBS::find_covering_region_containing(HeapWord* addr) { |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| if (_covered[i].contains(addr)) { |
| return i; |
| } |
| } |
| assert(0, "address outside of heap?"); |
| return -1; |
| } |
| |
| HeapWord* CardTableModRefBS::largest_prev_committed_end(int ind) const { |
| HeapWord* max_end = NULL; |
| for (int j = 0; j < ind; j++) { |
| HeapWord* this_end = _committed[j].end(); |
| if (this_end > max_end) max_end = this_end; |
| } |
| return max_end; |
| } |
| |
| MemRegion CardTableModRefBS::committed_unique_to_self(int self, |
| MemRegion mr) const { |
| MemRegion result = mr; |
| for (int r = 0; r < _cur_covered_regions; r += 1) { |
| if (r != self) { |
| result = result.minus(_committed[r]); |
| } |
| } |
| // Never include the guard page. |
| result = result.minus(_guard_region); |
| return result; |
| } |
| |
| void CardTableModRefBS::resize_covered_region(MemRegion new_region) { |
| // We don't change the start of a region, only the end. |
| assert(_whole_heap.contains(new_region), |
| "attempt to cover area not in reserved area"); |
| debug_only(verify_guard();) |
| // collided is true if the expansion would push into another committed region |
| debug_only(bool collided = false;) |
| int const ind = find_covering_region_by_base(new_region.start()); |
| MemRegion const old_region = _covered[ind]; |
| assert(old_region.start() == new_region.start(), "just checking"); |
| if (new_region.word_size() != old_region.word_size()) { |
| // Commit new or uncommit old pages, if necessary. |
| MemRegion cur_committed = _committed[ind]; |
| // Extend the end of this _commited region |
| // to cover the end of any lower _committed regions. |
| // This forms overlapping regions, but never interior regions. |
| HeapWord* const max_prev_end = largest_prev_committed_end(ind); |
| if (max_prev_end > cur_committed.end()) { |
| cur_committed.set_end(max_prev_end); |
| } |
| // Align the end up to a page size (starts are already aligned). |
| jbyte* const new_end = byte_after(new_region.last()); |
| HeapWord* new_end_aligned = |
| (HeapWord*) align_size_up((uintptr_t)new_end, _page_size); |
| assert(new_end_aligned >= (HeapWord*) new_end, |
| "align up, but less"); |
| // Check the other regions (excludes "ind") to ensure that |
| // the new_end_aligned does not intrude onto the committed |
| // space of another region. |
| int ri = 0; |
| for (ri = 0; ri < _cur_covered_regions; ri++) { |
| if (ri != ind) { |
| if (_committed[ri].contains(new_end_aligned)) { |
| // The prior check included in the assert |
| // (new_end_aligned >= _committed[ri].start()) |
| // is redundant with the "contains" test. |
| // Any region containing the new end |
| // should start at or beyond the region found (ind) |
| // for the new end (committed regions are not expected to |
| // be proper subsets of other committed regions). |
| assert(_committed[ri].start() >= _committed[ind].start(), |
| "New end of committed region is inconsistent"); |
| new_end_aligned = _committed[ri].start(); |
| // new_end_aligned can be equal to the start of its |
| // committed region (i.e., of "ind") if a second |
| // region following "ind" also start at the same location |
| // as "ind". |
| assert(new_end_aligned >= _committed[ind].start(), |
| "New end of committed region is before start"); |
| debug_only(collided = true;) |
| // Should only collide with 1 region |
| break; |
| } |
| } |
| } |
| #ifdef ASSERT |
| for (++ri; ri < _cur_covered_regions; ri++) { |
| assert(!_committed[ri].contains(new_end_aligned), |
| "New end of committed region is in a second committed region"); |
| } |
| #endif |
| // The guard page is always committed and should not be committed over. |
| // "guarded" is used for assertion checking below and recalls the fact |
| // that the would-be end of the new committed region would have |
| // penetrated the guard page. |
| HeapWord* new_end_for_commit = new_end_aligned; |
| |
| DEBUG_ONLY(bool guarded = false;) |
| if (new_end_for_commit > _guard_region.start()) { |
| new_end_for_commit = _guard_region.start(); |
| DEBUG_ONLY(guarded = true;) |
| } |
| |
| if (new_end_for_commit > cur_committed.end()) { |
| // Must commit new pages. |
| MemRegion const new_committed = |
| MemRegion(cur_committed.end(), new_end_for_commit); |
| |
| assert(!new_committed.is_empty(), "Region should not be empty here"); |
| os::commit_memory_or_exit((char*)new_committed.start(), |
| new_committed.byte_size(), _page_size, |
| !ExecMem, "card table expansion"); |
| // Use new_end_aligned (as opposed to new_end_for_commit) because |
| // the cur_committed region may include the guard region. |
| } else if (new_end_aligned < cur_committed.end()) { |
| // Must uncommit pages. |
| MemRegion const uncommit_region = |
| committed_unique_to_self(ind, MemRegion(new_end_aligned, |
| cur_committed.end())); |
| if (!uncommit_region.is_empty()) { |
| // It is not safe to uncommit cards if the boundary between |
| // the generations is moving. A shrink can uncommit cards |
| // owned by generation A but being used by generation B. |
| if (!UseAdaptiveGCBoundary) { |
| if (!os::uncommit_memory((char*)uncommit_region.start(), |
| uncommit_region.byte_size())) { |
| assert(false, "Card table contraction failed"); |
| // The call failed so don't change the end of the |
| // committed region. This is better than taking the |
| // VM down. |
| new_end_aligned = _committed[ind].end(); |
| } |
| } else { |
| new_end_aligned = _committed[ind].end(); |
| } |
| } |
| } |
| // In any case, we can reset the end of the current committed entry. |
| _committed[ind].set_end(new_end_aligned); |
| |
| #ifdef ASSERT |
| // Check that the last card in the new region is committed according |
| // to the tables. |
| bool covered = false; |
| for (int cr = 0; cr < _cur_covered_regions; cr++) { |
| if (_committed[cr].contains(new_end - 1)) { |
| covered = true; |
| break; |
| } |
| } |
| assert(covered, "Card for end of new region not committed"); |
| #endif |
| |
| // The default of 0 is not necessarily clean cards. |
| jbyte* entry; |
| if (old_region.last() < _whole_heap.start()) { |
| entry = byte_for(_whole_heap.start()); |
| } else { |
| entry = byte_after(old_region.last()); |
| } |
| assert(index_for(new_region.last()) < _guard_index, |
| "The guard card will be overwritten"); |
| // This line commented out cleans the newly expanded region and |
| // not the aligned up expanded region. |
| // jbyte* const end = byte_after(new_region.last()); |
| jbyte* const end = (jbyte*) new_end_for_commit; |
| assert((end >= byte_after(new_region.last())) || collided || guarded, |
| "Expect to be beyond new region unless impacting another region"); |
| // do nothing if we resized downward. |
| #ifdef ASSERT |
| for (int ri = 0; ri < _cur_covered_regions; ri++) { |
| if (ri != ind) { |
| // The end of the new committed region should not |
| // be in any existing region unless it matches |
| // the start of the next region. |
| assert(!_committed[ri].contains(end) || |
| (_committed[ri].start() == (HeapWord*) end), |
| "Overlapping committed regions"); |
| } |
| } |
| #endif |
| if (entry < end) { |
| memset(entry, clean_card, pointer_delta(end, entry, sizeof(jbyte))); |
| } |
| } |
| // In any case, the covered size changes. |
| _covered[ind].set_word_size(new_region.word_size()); |
| if (TraceCardTableModRefBS) { |
| gclog_or_tty->print_cr("CardTableModRefBS::resize_covered_region: "); |
| gclog_or_tty->print_cr(" " |
| " _covered[%d].start(): " INTPTR_FORMAT |
| " _covered[%d].last(): " INTPTR_FORMAT, |
| ind, p2i(_covered[ind].start()), |
| ind, p2i(_covered[ind].last())); |
| gclog_or_tty->print_cr(" " |
| " _committed[%d].start(): " INTPTR_FORMAT |
| " _committed[%d].last(): " INTPTR_FORMAT, |
| ind, p2i(_committed[ind].start()), |
| ind, p2i(_committed[ind].last())); |
| gclog_or_tty->print_cr(" " |
| " byte_for(start): " INTPTR_FORMAT |
| " byte_for(last): " INTPTR_FORMAT, |
| p2i(byte_for(_covered[ind].start())), |
| p2i(byte_for(_covered[ind].last()))); |
| gclog_or_tty->print_cr(" " |
| " addr_for(start): " INTPTR_FORMAT |
| " addr_for(last): " INTPTR_FORMAT, |
| p2i(addr_for((jbyte*) _committed[ind].start())), |
| p2i(addr_for((jbyte*) _committed[ind].last()))); |
| } |
| // Touch the last card of the covered region to show that it |
| // is committed (or SEGV). |
| debug_only((void) (*byte_for(_covered[ind].last()));) |
| debug_only(verify_guard();) |
| } |
| |
| // Note that these versions are precise! The scanning code has to handle the |
| // fact that the write barrier may be either precise or imprecise. |
| |
| void CardTableModRefBS::write_ref_field_work(void* field, oop newVal, bool release) { |
| inline_write_ref_field(field, newVal, release); |
| } |
| |
| |
| void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space* sp, |
| MemRegion mr, |
| OopsInGenClosure* cl, |
| CardTableRS* ct) { |
| if (!mr.is_empty()) { |
| // Caller (process_roots()) claims that all GC threads |
| // execute this call. With UseDynamicNumberOfGCThreads now all |
| // active GC threads execute this call. The number of active GC |
| // threads needs to be passed to par_non_clean_card_iterate_work() |
| // to get proper partitioning and termination. |
| // |
| // This is an example of where n_par_threads() is used instead |
| // of workers()->active_workers(). n_par_threads can be set to 0 to |
| // turn off parallelism. For example when this code is called as |
| // part of verification and SharedHeap::process_roots() is being |
| // used, then n_par_threads() may have been set to 0. active_workers |
| // is not overloaded with the meaning that it is a switch to disable |
| // parallelism and so keeps the meaning of the number of |
| // active gc workers. If parallelism has not been shut off by |
| // setting n_par_threads to 0, then n_par_threads should be |
| // equal to active_workers. When a different mechanism for shutting |
| // off parallelism is used, then active_workers can be used in |
| // place of n_par_threads. |
| // This is an example of a path where n_par_threads is |
| // set to 0 to turn off parallism. |
| // [7] CardTableModRefBS::non_clean_card_iterate() |
| // [8] CardTableRS::younger_refs_in_space_iterate() |
| // [9] Generation::younger_refs_in_space_iterate() |
| // [10] OneContigSpaceCardGeneration::younger_refs_iterate() |
| // [11] CompactingPermGenGen::younger_refs_iterate() |
| // [12] CardTableRS::younger_refs_iterate() |
| // [13] SharedHeap::process_strong_roots() |
| // [14] G1CollectedHeap::verify() |
| // [15] Universe::verify() |
| // [16] G1CollectedHeap::do_collection_pause_at_safepoint() |
| // |
| int n_threads = SharedHeap::heap()->n_par_threads(); |
| bool is_par = n_threads > 0; |
| if (is_par) { |
| #if INCLUDE_ALL_GCS |
| assert(SharedHeap::heap()->n_par_threads() == |
| SharedHeap::heap()->workers()->active_workers(), "Mismatch"); |
| non_clean_card_iterate_parallel_work(sp, mr, cl, ct, n_threads); |
| #else // INCLUDE_ALL_GCS |
| fatal("Parallel gc not supported here."); |
| #endif // INCLUDE_ALL_GCS |
| } else { |
| // We do not call the non_clean_card_iterate_serial() version below because |
| // we want to clear the cards (which non_clean_card_iterate_serial() does not |
| // do for us): clear_cl here does the work of finding contiguous dirty ranges |
| // of cards to process and clear. |
| |
| DirtyCardToOopClosure* dcto_cl = sp->new_dcto_cl(cl, precision(), |
| cl->gen_boundary()); |
| ClearNoncleanCardWrapper clear_cl(dcto_cl, ct); |
| |
| clear_cl.do_MemRegion(mr); |
| } |
| } |
| } |
| |
| // The iterator itself is not MT-aware, but |
| // MT-aware callers and closures can use this to |
| // accomplish dirty card iteration in parallel. The |
| // iterator itself does not clear the dirty cards, or |
| // change their values in any manner. |
| void CardTableModRefBS::non_clean_card_iterate_serial(MemRegion mr, |
| MemRegionClosure* cl) { |
| bool is_par = (SharedHeap::heap()->n_par_threads() > 0); |
| assert(!is_par || |
| (SharedHeap::heap()->n_par_threads() == |
| SharedHeap::heap()->workers()->active_workers()), "Mismatch"); |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| MemRegion mri = mr.intersection(_covered[i]); |
| if (mri.word_size() > 0) { |
| jbyte* cur_entry = byte_for(mri.last()); |
| jbyte* limit = byte_for(mri.start()); |
| while (cur_entry >= limit) { |
| jbyte* next_entry = cur_entry - 1; |
| if (*cur_entry != clean_card) { |
| size_t non_clean_cards = 1; |
| // Should the next card be included in this range of dirty cards. |
| while (next_entry >= limit && *next_entry != clean_card) { |
| non_clean_cards++; |
| cur_entry = next_entry; |
| next_entry--; |
| } |
| // The memory region may not be on a card boundary. So that |
| // objects beyond the end of the region are not processed, make |
| // cur_cards precise with regard to the end of the memory region. |
| MemRegion cur_cards(addr_for(cur_entry), |
| non_clean_cards * card_size_in_words); |
| MemRegion dirty_region = cur_cards.intersection(mri); |
| cl->do_MemRegion(dirty_region); |
| } |
| cur_entry = next_entry; |
| } |
| } |
| } |
| } |
| |
| void CardTableModRefBS::dirty_MemRegion(MemRegion mr) { |
| assert((HeapWord*)align_size_down((uintptr_t)mr.start(), HeapWordSize) == mr.start(), "Unaligned start"); |
| assert((HeapWord*)align_size_up ((uintptr_t)mr.end(), HeapWordSize) == mr.end(), "Unaligned end" ); |
| jbyte* cur = byte_for(mr.start()); |
| jbyte* last = byte_after(mr.last()); |
| while (cur < last) { |
| *cur = dirty_card; |
| cur++; |
| } |
| } |
| |
| void CardTableModRefBS::invalidate(MemRegion mr, bool whole_heap) { |
| assert((HeapWord*)align_size_down((uintptr_t)mr.start(), HeapWordSize) == mr.start(), "Unaligned start"); |
| assert((HeapWord*)align_size_up ((uintptr_t)mr.end(), HeapWordSize) == mr.end(), "Unaligned end" ); |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| MemRegion mri = mr.intersection(_covered[i]); |
| if (!mri.is_empty()) dirty_MemRegion(mri); |
| } |
| } |
| |
| void CardTableModRefBS::clear_MemRegion(MemRegion mr) { |
| // Be conservative: only clean cards entirely contained within the |
| // region. |
| jbyte* cur; |
| if (mr.start() == _whole_heap.start()) { |
| cur = byte_for(mr.start()); |
| } else { |
| assert(mr.start() > _whole_heap.start(), "mr is not covered."); |
| cur = byte_after(mr.start() - 1); |
| } |
| jbyte* last = byte_after(mr.last()); |
| memset(cur, clean_card, pointer_delta(last, cur, sizeof(jbyte))); |
| } |
| |
| void CardTableModRefBS::clear(MemRegion mr) { |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| MemRegion mri = mr.intersection(_covered[i]); |
| if (!mri.is_empty()) clear_MemRegion(mri); |
| } |
| } |
| |
| void CardTableModRefBS::dirty(MemRegion mr) { |
| jbyte* first = byte_for(mr.start()); |
| jbyte* last = byte_after(mr.last()); |
| memset(first, dirty_card, last-first); |
| } |
| |
| // Unlike several other card table methods, dirty_card_iterate() |
| // iterates over dirty cards ranges in increasing address order. |
| void CardTableModRefBS::dirty_card_iterate(MemRegion mr, |
| MemRegionClosure* cl) { |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| MemRegion mri = mr.intersection(_covered[i]); |
| if (!mri.is_empty()) { |
| jbyte *cur_entry, *next_entry, *limit; |
| for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last()); |
| cur_entry <= limit; |
| cur_entry = next_entry) { |
| next_entry = cur_entry + 1; |
| if (*cur_entry == dirty_card) { |
| size_t dirty_cards; |
| // Accumulate maximal dirty card range, starting at cur_entry |
| for (dirty_cards = 1; |
| next_entry <= limit && *next_entry == dirty_card; |
| dirty_cards++, next_entry++); |
| MemRegion cur_cards(addr_for(cur_entry), |
| dirty_cards*card_size_in_words); |
| cl->do_MemRegion(cur_cards); |
| } |
| } |
| } |
| } |
| } |
| |
| MemRegion CardTableModRefBS::dirty_card_range_after_reset(MemRegion mr, |
| bool reset, |
| int reset_val) { |
| for (int i = 0; i < _cur_covered_regions; i++) { |
| MemRegion mri = mr.intersection(_covered[i]); |
| if (!mri.is_empty()) { |
| jbyte* cur_entry, *next_entry, *limit; |
| for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last()); |
| cur_entry <= limit; |
| cur_entry = next_entry) { |
| next_entry = cur_entry + 1; |
| if (*cur_entry == dirty_card) { |
| size_t dirty_cards; |
| // Accumulate maximal dirty card range, starting at cur_entry |
| for (dirty_cards = 1; |
| next_entry <= limit && *next_entry == dirty_card; |
| dirty_cards++, next_entry++); |
| MemRegion cur_cards(addr_for(cur_entry), |
| dirty_cards*card_size_in_words); |
| if (reset) { |
| for (size_t i = 0; i < dirty_cards; i++) { |
| cur_entry[i] = reset_val; |
| } |
| } |
| return cur_cards; |
| } |
| } |
| } |
| } |
| return MemRegion(mr.end(), mr.end()); |
| } |
| |
| uintx CardTableModRefBS::ct_max_alignment_constraint() { |
| return card_size * os::vm_page_size(); |
| } |
| |
| void CardTableModRefBS::verify_guard() { |
| // For product build verification |
| guarantee(_byte_map[_guard_index] == last_card, |
| "card table guard has been modified"); |
| } |
| |
| void CardTableModRefBS::verify() { |
| verify_guard(); |
| } |
| |
| #ifndef PRODUCT |
| void CardTableModRefBS::verify_region(MemRegion mr, |
| jbyte val, bool val_equals) { |
| jbyte* start = byte_for(mr.start()); |
| jbyte* end = byte_for(mr.last()); |
| bool failures = false; |
| for (jbyte* curr = start; curr <= end; ++curr) { |
| jbyte curr_val = *curr; |
| bool failed = (val_equals) ? (curr_val != val) : (curr_val == val); |
| if (failed) { |
| if (!failures) { |
| tty->cr(); |
| tty->print_cr("== CT verification failed: [" INTPTR_FORMAT "," INTPTR_FORMAT "]", p2i(start), p2i(end)); |
| tty->print_cr("== %sexpecting value: %d", |
| (val_equals) ? "" : "not ", val); |
| failures = true; |
| } |
| tty->print_cr("== card "PTR_FORMAT" ["PTR_FORMAT","PTR_FORMAT"], " |
| "val: %d", p2i(curr), p2i(addr_for(curr)), |
| p2i((HeapWord*) (((size_t) addr_for(curr)) + card_size)), |
| (int) curr_val); |
| } |
| } |
| guarantee(!failures, "there should not have been any failures"); |
| } |
| |
| void CardTableModRefBS::verify_not_dirty_region(MemRegion mr) { |
| verify_region(mr, dirty_card, false /* val_equals */); |
| } |
| |
| void CardTableModRefBS::verify_dirty_region(MemRegion mr) { |
| verify_region(mr, dirty_card, true /* val_equals */); |
| } |
| #endif |
| |
| void CardTableModRefBS::print_on(outputStream* st) const { |
| st->print_cr("Card table byte_map: [" INTPTR_FORMAT "," INTPTR_FORMAT "] byte_map_base: " INTPTR_FORMAT, |
| p2i(_byte_map), p2i(_byte_map + _byte_map_size), p2i(byte_map_base)); |
| } |
| |
| bool CardTableModRefBSForCTRS::card_will_be_scanned(jbyte cv) { |
| return |
| CardTableModRefBS::card_will_be_scanned(cv) || |
| _rs->is_prev_nonclean_card_val(cv); |
| }; |
| |
| bool CardTableModRefBSForCTRS::card_may_have_been_dirty(jbyte cv) { |
| return |
| cv != clean_card && |
| (CardTableModRefBS::card_may_have_been_dirty(cv) || |
| CardTableRS::youngergen_may_have_been_dirty(cv)); |
| }; |
