aoqi@0: /*
aoqi@0:  * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@1: /*
aoqi@1:  * This file has been modified by Loongson Technology in 2015. These
aoqi@1:  * modifications are Copyright (c) 2015 Loongson Technology, and are made
aoqi@1:  * available on the same license terms set forth above.
aoqi@1:  */
aoqi@1: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "memory/allocation.inline.hpp"
aoqi@0: #include "memory/cardTableModRefBS.hpp"
aoqi@0: #include "memory/cardTableRS.hpp"
aoqi@0: #include "memory/sharedHeap.hpp"
aoqi@0: #include "memory/space.hpp"
aoqi@0: #include "memory/space.inline.hpp"
aoqi@0: #include "memory/universe.hpp"
aoqi@0: #include "runtime/java.hpp"
aoqi@0: #include "runtime/mutexLocker.hpp"
aoqi@0: #include "runtime/virtualspace.hpp"
aoqi@0: #include "services/memTracker.hpp"
aoqi@0: #include "utilities/macros.hpp"
aoqi@0: #ifdef COMPILER1
aoqi@0: #include "c1/c1_LIR.hpp"
aoqi@0: #include "c1/c1_LIRGenerator.hpp"
aoqi@0: #endif
aoqi@0: 
aoqi@0: // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
aoqi@0: // enumerate ref fields that have been modified (since the last
aoqi@0: // enumeration.)
aoqi@0: 
aoqi@0: size_t CardTableModRefBS::cards_required(size_t covered_words)
aoqi@0: {
aoqi@0:   // Add one for a guard card, used to detect errors.
aoqi@0:   const size_t words = align_size_up(covered_words, card_size_in_words);
aoqi@0:   return words / card_size_in_words + 1;
aoqi@0: }
aoqi@0: 
aoqi@0: size_t CardTableModRefBS::compute_byte_map_size()
aoqi@0: {
aoqi@0:   assert(_guard_index == cards_required(_whole_heap.word_size()) - 1,
aoqi@0:                                         "unitialized, check declaration order");
aoqi@0:   assert(_page_size != 0, "unitialized, check declaration order");
aoqi@0:   const size_t granularity = os::vm_allocation_granularity();
aoqi@0:   return align_size_up(_guard_index + 1, MAX2(_page_size, granularity));
aoqi@0: }
aoqi@0: 
aoqi@0: CardTableModRefBS::CardTableModRefBS(MemRegion whole_heap,
aoqi@0:                                      int max_covered_regions):
aoqi@0:   ModRefBarrierSet(max_covered_regions),
aoqi@0:   _whole_heap(whole_heap),
aoqi@0:   _guard_index(cards_required(whole_heap.word_size()) - 1),
aoqi@0:   _last_valid_index(_guard_index - 1),
aoqi@0:   _page_size(os::vm_page_size()),
aoqi@0:   _byte_map_size(compute_byte_map_size())
aoqi@0: {
aoqi@0:   _kind = BarrierSet::CardTableModRef;
aoqi@0: 
aoqi@0:   HeapWord* low_bound  = _whole_heap.start();
aoqi@0:   HeapWord* high_bound = _whole_heap.end();
aoqi@0:   assert((uintptr_t(low_bound)  & (card_size - 1))  == 0, "heap must start at card boundary");
aoqi@0:   assert((uintptr_t(high_bound) & (card_size - 1))  == 0, "heap must end at card boundary");
aoqi@0: 
aoqi@0:   assert(card_size <= 512, "card_size must be less than 512"); // why?
aoqi@0: 
aoqi@0:   _covered   = new MemRegion[max_covered_regions];
aoqi@0:   _committed = new MemRegion[max_covered_regions];
aoqi@0:   if (_covered == NULL || _committed == NULL) {
aoqi@0:     vm_exit_during_initialization("couldn't alloc card table covered region set.");
aoqi@0:   }
aoqi@0: 
aoqi@0:   _cur_covered_regions = 0;
aoqi@0:   const size_t rs_align = _page_size == (size_t) os::vm_page_size() ? 0 :
aoqi@0:     MAX2(_page_size, (size_t) os::vm_allocation_granularity());
aoqi@1: #ifdef MIPS64
aoqi@1:   /* 2013/10.25 Jin: try to allocate byte_map_base within 32-bit region.
aoqi@1:       FIXME: should automatically search a spare space. */ 
aoqi@1:   ReservedSpace heap_rs(_byte_map_size, rs_align, false, (char *)0x20000000);
aoqi@1: #else
aoqi@0:   ReservedSpace heap_rs(_byte_map_size, rs_align, false);
aoqi@1: #endif
aoqi@0:   MemTracker::record_virtual_memory_type((address)heap_rs.base(), mtGC);
aoqi@0: 
aoqi@0:   os::trace_page_sizes("card table", _guard_index + 1, _guard_index + 1,
aoqi@0:                        _page_size, heap_rs.base(), heap_rs.size());
aoqi@0:   if (!heap_rs.is_reserved()) {
aoqi@0:     vm_exit_during_initialization("Could not reserve enough space for the "
aoqi@0:                                   "card marking array");
aoqi@0:   }
aoqi@0: 
aoqi@0:   // The assember store_check code will do an unsigned shift of the oop,
aoqi@0:   // then add it to byte_map_base, i.e.
aoqi@0:   //
aoqi@0:   //   _byte_map = byte_map_base + (uintptr_t(low_bound) >> card_shift)
aoqi@0:   _byte_map = (jbyte*) heap_rs.base();
aoqi@0:   byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
aoqi@0:   assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
aoqi@0:   assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
aoqi@0: 
aoqi@0:   jbyte* guard_card = &_byte_map[_guard_index];
aoqi@0:   uintptr_t guard_page = align_size_down((uintptr_t)guard_card, _page_size);
aoqi@0:   _guard_region = MemRegion((HeapWord*)guard_page, _page_size);
aoqi@0:   os::commit_memory_or_exit((char*)guard_page, _page_size, _page_size,
aoqi@0:                             !ExecMem, "card table last card");
aoqi@0:   *guard_card = last_card;
aoqi@0: 
aoqi@0:    _lowest_non_clean =
aoqi@0:     NEW_C_HEAP_ARRAY(CardArr, max_covered_regions, mtGC);
aoqi@0:   _lowest_non_clean_chunk_size =
aoqi@0:     NEW_C_HEAP_ARRAY(size_t, max_covered_regions, mtGC);
aoqi@0:   _lowest_non_clean_base_chunk_index =
aoqi@0:     NEW_C_HEAP_ARRAY(uintptr_t, max_covered_regions, mtGC);
aoqi@0:   _last_LNC_resizing_collection =
aoqi@0:     NEW_C_HEAP_ARRAY(int, max_covered_regions, mtGC);
aoqi@0:   if (_lowest_non_clean == NULL
aoqi@0:       || _lowest_non_clean_chunk_size == NULL
aoqi@0:       || _lowest_non_clean_base_chunk_index == NULL
aoqi@0:       || _last_LNC_resizing_collection == NULL)
aoqi@0:     vm_exit_during_initialization("couldn't allocate an LNC array.");
aoqi@0:   for (int i = 0; i < max_covered_regions; i++) {
aoqi@0:     _lowest_non_clean[i] = NULL;
aoqi@0:     _lowest_non_clean_chunk_size[i] = 0;
aoqi@0:     _last_LNC_resizing_collection[i] = -1;
aoqi@0:   }
aoqi@0: 
aoqi@0:   if (TraceCardTableModRefBS) {
aoqi@0:     gclog_or_tty->print_cr("CardTableModRefBS::CardTableModRefBS: ");
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  &_byte_map[0]: " INTPTR_FORMAT
aoqi@0:                   "  &_byte_map[_last_valid_index]: " INTPTR_FORMAT,
aoqi@0:                   p2i(&_byte_map[0]),
aoqi@0:                   p2i(&_byte_map[_last_valid_index]));
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  byte_map_base: " INTPTR_FORMAT,
aoqi@0:                   p2i(byte_map_base));
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: CardTableModRefBS::~CardTableModRefBS() {
aoqi@0:   if (_covered) {
aoqi@0:     delete[] _covered;
aoqi@0:     _covered = NULL;
aoqi@0:   }
aoqi@0:   if (_committed) {
aoqi@0:     delete[] _committed;
aoqi@0:     _committed = NULL;
aoqi@0:   }
aoqi@0:   if (_lowest_non_clean) {
aoqi@0:     FREE_C_HEAP_ARRAY(CardArr, _lowest_non_clean, mtGC);
aoqi@0:     _lowest_non_clean = NULL;
aoqi@0:   }
aoqi@0:   if (_lowest_non_clean_chunk_size) {
aoqi@0:     FREE_C_HEAP_ARRAY(size_t, _lowest_non_clean_chunk_size, mtGC);
aoqi@0:     _lowest_non_clean_chunk_size = NULL;
aoqi@0:   }
aoqi@0:   if (_lowest_non_clean_base_chunk_index) {
aoqi@0:     FREE_C_HEAP_ARRAY(uintptr_t, _lowest_non_clean_base_chunk_index, mtGC);
aoqi@0:     _lowest_non_clean_base_chunk_index = NULL;
aoqi@0:   }
aoqi@0:   if (_last_LNC_resizing_collection) {
aoqi@0:     FREE_C_HEAP_ARRAY(int, _last_LNC_resizing_collection, mtGC);
aoqi@0:     _last_LNC_resizing_collection = NULL;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: int CardTableModRefBS::find_covering_region_by_base(HeapWord* base) {
aoqi@0:   int i;
aoqi@0:   for (i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     if (_covered[i].start() == base) return i;
aoqi@0:     if (_covered[i].start() > base) break;
aoqi@0:   }
aoqi@0:   // If we didn't find it, create a new one.
aoqi@0:   assert(_cur_covered_regions < _max_covered_regions,
aoqi@0:          "too many covered regions");
aoqi@0:   // Move the ones above up, to maintain sorted order.
aoqi@0:   for (int j = _cur_covered_regions; j > i; j--) {
aoqi@0:     _covered[j] = _covered[j-1];
aoqi@0:     _committed[j] = _committed[j-1];
aoqi@0:   }
aoqi@0:   int res = i;
aoqi@0:   _cur_covered_regions++;
aoqi@0:   _covered[res].set_start(base);
aoqi@0:   _covered[res].set_word_size(0);
aoqi@0:   jbyte* ct_start = byte_for(base);
aoqi@0:   uintptr_t ct_start_aligned = align_size_down((uintptr_t)ct_start, _page_size);
aoqi@0:   _committed[res].set_start((HeapWord*)ct_start_aligned);
aoqi@0:   _committed[res].set_word_size(0);
aoqi@0:   return res;
aoqi@0: }
aoqi@0: 
aoqi@0: int CardTableModRefBS::find_covering_region_containing(HeapWord* addr) {
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     if (_covered[i].contains(addr)) {
aoqi@0:       return i;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   assert(0, "address outside of heap?");
aoqi@0:   return -1;
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord* CardTableModRefBS::largest_prev_committed_end(int ind) const {
aoqi@0:   HeapWord* max_end = NULL;
aoqi@0:   for (int j = 0; j < ind; j++) {
aoqi@0:     HeapWord* this_end = _committed[j].end();
aoqi@0:     if (this_end > max_end) max_end = this_end;
aoqi@0:   }
aoqi@0:   return max_end;
aoqi@0: }
aoqi@0: 
aoqi@0: MemRegion CardTableModRefBS::committed_unique_to_self(int self,
aoqi@0:                                                       MemRegion mr) const {
aoqi@0:   MemRegion result = mr;
aoqi@0:   for (int r = 0; r < _cur_covered_regions; r += 1) {
aoqi@0:     if (r != self) {
aoqi@0:       result = result.minus(_committed[r]);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // Never include the guard page.
aoqi@0:   result = result.minus(_guard_region);
aoqi@0:   return result;
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
aoqi@0:   // We don't change the start of a region, only the end.
aoqi@0:   assert(_whole_heap.contains(new_region),
aoqi@0:            "attempt to cover area not in reserved area");
aoqi@0:   debug_only(verify_guard();)
aoqi@0:   // collided is true if the expansion would push into another committed region
aoqi@0:   debug_only(bool collided = false;)
aoqi@0:   int const ind = find_covering_region_by_base(new_region.start());
aoqi@0:   MemRegion const old_region = _covered[ind];
aoqi@0:   assert(old_region.start() == new_region.start(), "just checking");
aoqi@0:   if (new_region.word_size() != old_region.word_size()) {
aoqi@0:     // Commit new or uncommit old pages, if necessary.
aoqi@0:     MemRegion cur_committed = _committed[ind];
aoqi@0:     // Extend the end of this _commited region
aoqi@0:     // to cover the end of any lower _committed regions.
aoqi@0:     // This forms overlapping regions, but never interior regions.
aoqi@0:     HeapWord* const max_prev_end = largest_prev_committed_end(ind);
aoqi@0:     if (max_prev_end > cur_committed.end()) {
aoqi@0:       cur_committed.set_end(max_prev_end);
aoqi@0:     }
aoqi@0:     // Align the end up to a page size (starts are already aligned).
aoqi@0:     jbyte* const new_end = byte_after(new_region.last());
aoqi@0:     HeapWord* new_end_aligned =
aoqi@0:       (HeapWord*) align_size_up((uintptr_t)new_end, _page_size);
aoqi@0:     assert(new_end_aligned >= (HeapWord*) new_end,
aoqi@0:            "align up, but less");
aoqi@0:     // Check the other regions (excludes "ind") to ensure that
aoqi@0:     // the new_end_aligned does not intrude onto the committed
aoqi@0:     // space of another region.
aoqi@0:     int ri = 0;
aoqi@0:     for (ri = 0; ri < _cur_covered_regions; ri++) {
aoqi@0:       if (ri != ind) {
aoqi@0:         if (_committed[ri].contains(new_end_aligned)) {
aoqi@0:           // The prior check included in the assert
aoqi@0:           // (new_end_aligned >= _committed[ri].start())
aoqi@0:           // is redundant with the "contains" test.
aoqi@0:           // Any region containing the new end
aoqi@0:           // should start at or beyond the region found (ind)
aoqi@0:           // for the new end (committed regions are not expected to
aoqi@0:           // be proper subsets of other committed regions).
aoqi@0:           assert(_committed[ri].start() >= _committed[ind].start(),
aoqi@0:                  "New end of committed region is inconsistent");
aoqi@0:           new_end_aligned = _committed[ri].start();
aoqi@0:           // new_end_aligned can be equal to the start of its
aoqi@0:           // committed region (i.e., of "ind") if a second
aoqi@0:           // region following "ind" also start at the same location
aoqi@0:           // as "ind".
aoqi@0:           assert(new_end_aligned >= _committed[ind].start(),
aoqi@0:             "New end of committed region is before start");
aoqi@0:           debug_only(collided = true;)
aoqi@0:           // Should only collide with 1 region
aoqi@0:           break;
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0: #ifdef ASSERT
aoqi@0:     for (++ri; ri < _cur_covered_regions; ri++) {
aoqi@0:       assert(!_committed[ri].contains(new_end_aligned),
aoqi@0:         "New end of committed region is in a second committed region");
aoqi@0:     }
aoqi@0: #endif
aoqi@0:     // The guard page is always committed and should not be committed over.
aoqi@0:     // "guarded" is used for assertion checking below and recalls the fact
aoqi@0:     // that the would-be end of the new committed region would have
aoqi@0:     // penetrated the guard page.
aoqi@0:     HeapWord* new_end_for_commit = new_end_aligned;
aoqi@0: 
aoqi@0:     DEBUG_ONLY(bool guarded = false;)
aoqi@0:     if (new_end_for_commit > _guard_region.start()) {
aoqi@0:       new_end_for_commit = _guard_region.start();
aoqi@0:       DEBUG_ONLY(guarded = true;)
aoqi@0:     }
aoqi@0: 
aoqi@0:     if (new_end_for_commit > cur_committed.end()) {
aoqi@0:       // Must commit new pages.
aoqi@0:       MemRegion const new_committed =
aoqi@0:         MemRegion(cur_committed.end(), new_end_for_commit);
aoqi@0: 
aoqi@0:       assert(!new_committed.is_empty(), "Region should not be empty here");
aoqi@0:       os::commit_memory_or_exit((char*)new_committed.start(),
aoqi@0:                                 new_committed.byte_size(), _page_size,
aoqi@0:                                 !ExecMem, "card table expansion");
aoqi@0:     // Use new_end_aligned (as opposed to new_end_for_commit) because
aoqi@0:     // the cur_committed region may include the guard region.
aoqi@0:     } else if (new_end_aligned < cur_committed.end()) {
aoqi@0:       // Must uncommit pages.
aoqi@0:       MemRegion const uncommit_region =
aoqi@0:         committed_unique_to_self(ind, MemRegion(new_end_aligned,
aoqi@0:                                                 cur_committed.end()));
aoqi@0:       if (!uncommit_region.is_empty()) {
aoqi@0:         // It is not safe to uncommit cards if the boundary between
aoqi@0:         // the generations is moving.  A shrink can uncommit cards
aoqi@0:         // owned by generation A but being used by generation B.
aoqi@0:         if (!UseAdaptiveGCBoundary) {
aoqi@0:           if (!os::uncommit_memory((char*)uncommit_region.start(),
aoqi@0:                                    uncommit_region.byte_size())) {
aoqi@0:             assert(false, "Card table contraction failed");
aoqi@0:             // The call failed so don't change the end of the
aoqi@0:             // committed region.  This is better than taking the
aoqi@0:             // VM down.
aoqi@0:             new_end_aligned = _committed[ind].end();
aoqi@0:           }
aoqi@0:         } else {
aoqi@0:           new_end_aligned = _committed[ind].end();
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:     // In any case, we can reset the end of the current committed entry.
aoqi@0:     _committed[ind].set_end(new_end_aligned);
aoqi@0: 
aoqi@0: #ifdef ASSERT
aoqi@0:     // Check that the last card in the new region is committed according
aoqi@0:     // to the tables.
aoqi@0:     bool covered = false;
aoqi@0:     for (int cr = 0; cr < _cur_covered_regions; cr++) {
aoqi@0:       if (_committed[cr].contains(new_end - 1)) {
aoqi@0:         covered = true;
aoqi@0:         break;
aoqi@0:       }
aoqi@0:     }
aoqi@0:     assert(covered, "Card for end of new region not committed");
aoqi@0: #endif
aoqi@0: 
aoqi@0:     // The default of 0 is not necessarily clean cards.
aoqi@0:     jbyte* entry;
aoqi@0:     if (old_region.last() < _whole_heap.start()) {
aoqi@0:       entry = byte_for(_whole_heap.start());
aoqi@0:     } else {
aoqi@0:       entry = byte_after(old_region.last());
aoqi@0:     }
aoqi@0:     assert(index_for(new_region.last()) <  _guard_index,
aoqi@0:       "The guard card will be overwritten");
aoqi@0:     // This line commented out cleans the newly expanded region and
aoqi@0:     // not the aligned up expanded region.
aoqi@0:     // jbyte* const end = byte_after(new_region.last());
aoqi@0:     jbyte* const end = (jbyte*) new_end_for_commit;
aoqi@0:     assert((end >= byte_after(new_region.last())) || collided || guarded,
aoqi@0:       "Expect to be beyond new region unless impacting another region");
aoqi@0:     // do nothing if we resized downward.
aoqi@0: #ifdef ASSERT
aoqi@0:     for (int ri = 0; ri < _cur_covered_regions; ri++) {
aoqi@0:       if (ri != ind) {
aoqi@0:         // The end of the new committed region should not
aoqi@0:         // be in any existing region unless it matches
aoqi@0:         // the start of the next region.
aoqi@0:         assert(!_committed[ri].contains(end) ||
aoqi@0:                (_committed[ri].start() == (HeapWord*) end),
aoqi@0:                "Overlapping committed regions");
aoqi@0:       }
aoqi@0:     }
aoqi@0: #endif
aoqi@0:     if (entry < end) {
aoqi@0:       memset(entry, clean_card, pointer_delta(end, entry, sizeof(jbyte)));
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // In any case, the covered size changes.
aoqi@0:   _covered[ind].set_word_size(new_region.word_size());
aoqi@0:   if (TraceCardTableModRefBS) {
aoqi@0:     gclog_or_tty->print_cr("CardTableModRefBS::resize_covered_region: ");
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  _covered[%d].start(): " INTPTR_FORMAT
aoqi@0:                   "  _covered[%d].last(): " INTPTR_FORMAT,
aoqi@0:                   ind, p2i(_covered[ind].start()),
aoqi@0:                   ind, p2i(_covered[ind].last()));
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  _committed[%d].start(): " INTPTR_FORMAT
aoqi@0:                   "  _committed[%d].last(): " INTPTR_FORMAT,
aoqi@0:                   ind, p2i(_committed[ind].start()),
aoqi@0:                   ind, p2i(_committed[ind].last()));
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  byte_for(start): " INTPTR_FORMAT
aoqi@0:                   "  byte_for(last): " INTPTR_FORMAT,
aoqi@0:                   p2i(byte_for(_covered[ind].start())),
aoqi@0:                   p2i(byte_for(_covered[ind].last())));
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  addr_for(start): " INTPTR_FORMAT
aoqi@0:                   "  addr_for(last): " INTPTR_FORMAT,
aoqi@0:                   p2i(addr_for((jbyte*) _committed[ind].start())),
aoqi@0:                   p2i(addr_for((jbyte*) _committed[ind].last())));
aoqi@0:   }
aoqi@0:   // Touch the last card of the covered region to show that it
aoqi@0:   // is committed (or SEGV).
aoqi@0:   debug_only((void) (*byte_for(_covered[ind].last()));)
aoqi@0:   debug_only(verify_guard();)
aoqi@0: }
aoqi@0: 
aoqi@0: // Note that these versions are precise!  The scanning code has to handle the
aoqi@0: // fact that the write barrier may be either precise or imprecise.
aoqi@0: 
aoqi@0: void CardTableModRefBS::write_ref_field_work(void* field, oop newVal, bool release) {
aoqi@0:   inline_write_ref_field(field, newVal, release);
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space* sp,
aoqi@0:                                                                  MemRegion mr,
aoqi@0:                                                                  OopsInGenClosure* cl,
aoqi@0:                                                                  CardTableRS* ct) {
aoqi@0:   if (!mr.is_empty()) {
aoqi@0:     // Caller (process_strong_roots()) claims that all GC threads
aoqi@0:     // execute this call.  With UseDynamicNumberOfGCThreads now all
aoqi@0:     // active GC threads execute this call.  The number of active GC
aoqi@0:     // threads needs to be passed to par_non_clean_card_iterate_work()
aoqi@0:     // to get proper partitioning and termination.
aoqi@0:     //
aoqi@0:     // This is an example of where n_par_threads() is used instead
aoqi@0:     // of workers()->active_workers().  n_par_threads can be set to 0 to
aoqi@0:     // turn off parallelism.  For example when this code is called as
aoqi@0:     // part of verification and SharedHeap::process_strong_roots() is being
aoqi@0:     // used, then n_par_threads() may have been set to 0.  active_workers
aoqi@0:     // is not overloaded with the meaning that it is a switch to disable
aoqi@0:     // parallelism and so keeps the meaning of the number of
aoqi@0:     // active gc workers.  If parallelism has not been shut off by
aoqi@0:     // setting n_par_threads to 0, then n_par_threads should be
aoqi@0:     // equal to active_workers.  When a different mechanism for shutting
aoqi@0:     // off parallelism is used, then active_workers can be used in
aoqi@0:     // place of n_par_threads.
aoqi@0:     //  This is an example of a path where n_par_threads is
aoqi@0:     // set to 0 to turn off parallism.
aoqi@0:     //  [7] CardTableModRefBS::non_clean_card_iterate()
aoqi@0:     //  [8] CardTableRS::younger_refs_in_space_iterate()
aoqi@0:     //  [9] Generation::younger_refs_in_space_iterate()
aoqi@0:     //  [10] OneContigSpaceCardGeneration::younger_refs_iterate()
aoqi@0:     //  [11] CompactingPermGenGen::younger_refs_iterate()
aoqi@0:     //  [12] CardTableRS::younger_refs_iterate()
aoqi@0:     //  [13] SharedHeap::process_strong_roots()
aoqi@0:     //  [14] G1CollectedHeap::verify()
aoqi@0:     //  [15] Universe::verify()
aoqi@0:     //  [16] G1CollectedHeap::do_collection_pause_at_safepoint()
aoqi@0:     //
aoqi@0:     int n_threads =  SharedHeap::heap()->n_par_threads();
aoqi@0:     bool is_par = n_threads > 0;
aoqi@0:     if (is_par) {
aoqi@0: #if INCLUDE_ALL_GCS
aoqi@0:       assert(SharedHeap::heap()->n_par_threads() ==
aoqi@0:              SharedHeap::heap()->workers()->active_workers(), "Mismatch");
aoqi@0:       non_clean_card_iterate_parallel_work(sp, mr, cl, ct, n_threads);
aoqi@0: #else  // INCLUDE_ALL_GCS
aoqi@0:       fatal("Parallel gc not supported here.");
aoqi@0: #endif // INCLUDE_ALL_GCS
aoqi@0:     } else {
aoqi@0:       // We do not call the non_clean_card_iterate_serial() version below because
aoqi@0:       // we want to clear the cards (which non_clean_card_iterate_serial() does not
aoqi@0:       // do for us): clear_cl here does the work of finding contiguous dirty ranges
aoqi@0:       // of cards to process and clear.
aoqi@0: 
aoqi@0:       DirtyCardToOopClosure* dcto_cl = sp->new_dcto_cl(cl, precision(),
aoqi@0:                                                        cl->gen_boundary());
aoqi@0:       ClearNoncleanCardWrapper clear_cl(dcto_cl, ct);
aoqi@0: 
aoqi@0:       clear_cl.do_MemRegion(mr);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // The iterator itself is not MT-aware, but
aoqi@0: // MT-aware callers and closures can use this to
aoqi@0: // accomplish dirty card iteration in parallel. The
aoqi@0: // iterator itself does not clear the dirty cards, or
aoqi@0: // change their values in any manner.
aoqi@0: void CardTableModRefBS::non_clean_card_iterate_serial(MemRegion mr,
aoqi@0:                                                       MemRegionClosure* cl) {
aoqi@0:   bool is_par = (SharedHeap::heap()->n_par_threads() > 0);
aoqi@0:   assert(!is_par ||
aoqi@0:           (SharedHeap::heap()->n_par_threads() ==
aoqi@0:           SharedHeap::heap()->workers()->active_workers()), "Mismatch");
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     MemRegion mri = mr.intersection(_covered[i]);
aoqi@0:     if (mri.word_size() > 0) {
aoqi@0:       jbyte* cur_entry = byte_for(mri.last());
aoqi@0:       jbyte* limit = byte_for(mri.start());
aoqi@0:       while (cur_entry >= limit) {
aoqi@0:         jbyte* next_entry = cur_entry - 1;
aoqi@0:         if (*cur_entry != clean_card) {
aoqi@0:           size_t non_clean_cards = 1;
aoqi@0:           // Should the next card be included in this range of dirty cards.
aoqi@0:           while (next_entry >= limit && *next_entry != clean_card) {
aoqi@0:             non_clean_cards++;
aoqi@0:             cur_entry = next_entry;
aoqi@0:             next_entry--;
aoqi@0:           }
aoqi@0:           // The memory region may not be on a card boundary.  So that
aoqi@0:           // objects beyond the end of the region are not processed, make
aoqi@0:           // cur_cards precise with regard to the end of the memory region.
aoqi@0:           MemRegion cur_cards(addr_for(cur_entry),
aoqi@0:                               non_clean_cards * card_size_in_words);
aoqi@0:           MemRegion dirty_region = cur_cards.intersection(mri);
aoqi@0:           cl->do_MemRegion(dirty_region);
aoqi@0:         }
aoqi@0:         cur_entry = next_entry;
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::dirty_MemRegion(MemRegion mr) {
aoqi@0:   assert((HeapWord*)align_size_down((uintptr_t)mr.start(), HeapWordSize) == mr.start(), "Unaligned start");
aoqi@0:   assert((HeapWord*)align_size_up  ((uintptr_t)mr.end(),   HeapWordSize) == mr.end(),   "Unaligned end"  );
aoqi@0:   jbyte* cur  = byte_for(mr.start());
aoqi@0:   jbyte* last = byte_after(mr.last());
aoqi@0:   while (cur < last) {
aoqi@0:     *cur = dirty_card;
aoqi@0:     cur++;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::invalidate(MemRegion mr, bool whole_heap) {
aoqi@0:   assert((HeapWord*)align_size_down((uintptr_t)mr.start(), HeapWordSize) == mr.start(), "Unaligned start");
aoqi@0:   assert((HeapWord*)align_size_up  ((uintptr_t)mr.end(),   HeapWordSize) == mr.end(),   "Unaligned end"  );
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     MemRegion mri = mr.intersection(_covered[i]);
aoqi@0:     if (!mri.is_empty()) dirty_MemRegion(mri);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::clear_MemRegion(MemRegion mr) {
aoqi@0:   // Be conservative: only clean cards entirely contained within the
aoqi@0:   // region.
aoqi@0:   jbyte* cur;
aoqi@0:   if (mr.start() == _whole_heap.start()) {
aoqi@0:     cur = byte_for(mr.start());
aoqi@0:   } else {
aoqi@0:     assert(mr.start() > _whole_heap.start(), "mr is not covered.");
aoqi@0:     cur = byte_after(mr.start() - 1);
aoqi@0:   }
aoqi@0:   jbyte* last = byte_after(mr.last());
aoqi@0:   memset(cur, clean_card, pointer_delta(last, cur, sizeof(jbyte)));
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::clear(MemRegion mr) {
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     MemRegion mri = mr.intersection(_covered[i]);
aoqi@0:     if (!mri.is_empty()) clear_MemRegion(mri);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::dirty(MemRegion mr) {
aoqi@0:   jbyte* first = byte_for(mr.start());
aoqi@0:   jbyte* last  = byte_after(mr.last());
aoqi@0:   memset(first, dirty_card, last-first);
aoqi@0: }
aoqi@0: 
aoqi@0: // Unlike several other card table methods, dirty_card_iterate()
aoqi@0: // iterates over dirty cards ranges in increasing address order.
aoqi@0: void CardTableModRefBS::dirty_card_iterate(MemRegion mr,
aoqi@0:                                            MemRegionClosure* cl) {
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     MemRegion mri = mr.intersection(_covered[i]);
aoqi@0:     if (!mri.is_empty()) {
aoqi@0:       jbyte *cur_entry, *next_entry, *limit;
aoqi@0:       for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last());
aoqi@0:            cur_entry <= limit;
aoqi@0:            cur_entry  = next_entry) {
aoqi@0:         next_entry = cur_entry + 1;
aoqi@0:         if (*cur_entry == dirty_card) {
aoqi@0:           size_t dirty_cards;
aoqi@0:           // Accumulate maximal dirty card range, starting at cur_entry
aoqi@0:           for (dirty_cards = 1;
aoqi@0:                next_entry <= limit && *next_entry == dirty_card;
aoqi@0:                dirty_cards++, next_entry++);
aoqi@0:           MemRegion cur_cards(addr_for(cur_entry),
aoqi@0:                               dirty_cards*card_size_in_words);
aoqi@0:           cl->do_MemRegion(cur_cards);
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: MemRegion CardTableModRefBS::dirty_card_range_after_reset(MemRegion mr,
aoqi@0:                                                           bool reset,
aoqi@0:                                                           int reset_val) {
aoqi@0:   for (int i = 0; i < _cur_covered_regions; i++) {
aoqi@0:     MemRegion mri = mr.intersection(_covered[i]);
aoqi@0:     if (!mri.is_empty()) {
aoqi@0:       jbyte* cur_entry, *next_entry, *limit;
aoqi@0:       for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last());
aoqi@0:            cur_entry <= limit;
aoqi@0:            cur_entry  = next_entry) {
aoqi@0:         next_entry = cur_entry + 1;
aoqi@0:         if (*cur_entry == dirty_card) {
aoqi@0:           size_t dirty_cards;
aoqi@0:           // Accumulate maximal dirty card range, starting at cur_entry
aoqi@0:           for (dirty_cards = 1;
aoqi@0:                next_entry <= limit && *next_entry == dirty_card;
aoqi@0:                dirty_cards++, next_entry++);
aoqi@0:           MemRegion cur_cards(addr_for(cur_entry),
aoqi@0:                               dirty_cards*card_size_in_words);
aoqi@0:           if (reset) {
aoqi@0:             for (size_t i = 0; i < dirty_cards; i++) {
aoqi@0:               cur_entry[i] = reset_val;
aoqi@0:             }
aoqi@0:           }
aoqi@0:           return cur_cards;
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return MemRegion(mr.end(), mr.end());
aoqi@0: }
aoqi@0: 
aoqi@0: uintx CardTableModRefBS::ct_max_alignment_constraint() {
aoqi@0:   return card_size * os::vm_page_size();
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::verify_guard() {
aoqi@0:   // For product build verification
aoqi@0:   guarantee(_byte_map[_guard_index] == last_card,
aoqi@0:             "card table guard has been modified");
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::verify() {
aoqi@0:   verify_guard();
aoqi@0: }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0: void CardTableModRefBS::verify_region(MemRegion mr,
aoqi@0:                                       jbyte val, bool val_equals) {
aoqi@0:   jbyte* start    = byte_for(mr.start());
aoqi@0:   jbyte* end      = byte_for(mr.last());
aoqi@0:   bool   failures = false;
aoqi@0:   for (jbyte* curr = start; curr <= end; ++curr) {
aoqi@0:     jbyte curr_val = *curr;
aoqi@0:     bool failed = (val_equals) ? (curr_val != val) : (curr_val == val);
aoqi@0:     if (failed) {
aoqi@0:       if (!failures) {
aoqi@0:         tty->cr();
aoqi@0:         tty->print_cr("== CT verification failed: [" INTPTR_FORMAT "," INTPTR_FORMAT "]", p2i(start), p2i(end));
aoqi@0:         tty->print_cr("==   %sexpecting value: %d",
aoqi@0:                       (val_equals) ? "" : "not ", val);
aoqi@0:         failures = true;
aoqi@0:       }
aoqi@0:       tty->print_cr("==   card "PTR_FORMAT" ["PTR_FORMAT","PTR_FORMAT"], "
aoqi@0:                     "val: %d", p2i(curr), p2i(addr_for(curr)),
aoqi@0:                     p2i((HeapWord*) (((size_t) addr_for(curr)) + card_size)),
aoqi@0:                     (int) curr_val);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   guarantee(!failures, "there should not have been any failures");
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::verify_not_dirty_region(MemRegion mr) {
aoqi@0:   verify_region(mr, dirty_card, false /* val_equals */);
aoqi@0: }
aoqi@0: 
aoqi@0: void CardTableModRefBS::verify_dirty_region(MemRegion mr) {
aoqi@0:   verify_region(mr, dirty_card, true /* val_equals */);
aoqi@0: }
aoqi@0: #endif
aoqi@0: 
aoqi@0: void CardTableModRefBS::print_on(outputStream* st) const {
aoqi@0:   st->print_cr("Card table byte_map: [" INTPTR_FORMAT "," INTPTR_FORMAT "] byte_map_base: " INTPTR_FORMAT,
aoqi@0:                p2i(_byte_map), p2i(_byte_map + _byte_map_size), p2i(byte_map_base));
aoqi@0: }
aoqi@0: 
aoqi@0: bool CardTableModRefBSForCTRS::card_will_be_scanned(jbyte cv) {
aoqi@0:   return
aoqi@0:     CardTableModRefBS::card_will_be_scanned(cv) ||
aoqi@0:     _rs->is_prev_nonclean_card_val(cv);
aoqi@0: };
aoqi@0: 
aoqi@0: bool CardTableModRefBSForCTRS::card_may_have_been_dirty(jbyte cv) {
aoqi@0:   return
aoqi@0:     cv != clean_card &&
aoqi@0:     (CardTableModRefBS::card_may_have_been_dirty(cv) ||
aoqi@0:      CardTableRS::youngergen_may_have_been_dirty(cv));
aoqi@0: };