graal-compiler: src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp comparison

comparison src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp @ 342:37f87013dfd8

6711316: Open source the Garbage-First garbage collector Summary: First mercurial integration of the code for the Garbage-First garbage collector. Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

author	ysr
date	Thu, 05 Jun 2008 15:57:56 -0700
parents
children	e0c09f7ec5c4

comparison

equal deleted inserted replaced

-:0b27f3512f9e
+:37f87013dfd8
+/*
+* 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.
+*
+*/
+#include "incls/_precompiled.incl"
+#include "incls/_g1BlockOffsetTable.cpp.incl"
+//////////////////////////////////////////////////////////////////////
+// G1BlockOffsetSharedArray
+//////////////////////////////////////////////////////////////////////
+G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion reserved,
+size_t init_word_size) :
+_reserved(reserved), _end(NULL)
+{
+size_t size = compute_size(reserved.word_size());
+ReservedSpace rs(ReservedSpace::allocation_align_size_up(size));
+if (!rs.is_reserved()) {
+vm_exit_during_initialization("Could not reserve enough space for heap offset array");
+}
+if (!_vs.initialize(rs, 0)) {
+vm_exit_during_initialization("Could not reserve enough space for heap offset array");
+}
+_offset_array = (u_char*)_vs.low_boundary();
+resize(init_word_size);
+if (TraceBlockOffsetTable) {
+gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: ");
+gclog_or_tty->print_cr("  "
+"  rs.base(): " INTPTR_FORMAT
+"  rs.size(): " INTPTR_FORMAT
+"  rs end(): " INTPTR_FORMAT,
+rs.base(), rs.size(), rs.base() + rs.size());
+gclog_or_tty->print_cr("  "
+"  _vs.low_boundary(): " INTPTR_FORMAT
+"  _vs.high_boundary(): " INTPTR_FORMAT,
+_vs.low_boundary(),
+_vs.high_boundary());
+}
+}
+void G1BlockOffsetSharedArray::resize(size_t new_word_size) {
+assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved");
+size_t new_size = compute_size(new_word_size);
+size_t old_size = _vs.committed_size();
+size_t delta;
+char* high = _vs.high();
+_end = _reserved.start() + new_word_size;
+if (new_size > old_size) {
+delta = ReservedSpace::page_align_size_up(new_size - old_size);
+assert(delta > 0, "just checking");
+if (!_vs.expand_by(delta)) {
+// Do better than this for Merlin
+vm_exit_out_of_memory(delta, "offset table expansion");
+}
+assert(_vs.high() == high + delta, "invalid expansion");
+// Initialization of the contents is left to the
+// G1BlockOffsetArray that uses it.
+} else {
+delta = ReservedSpace::page_align_size_down(old_size - new_size);
+if (delta == 0) return;
+_vs.shrink_by(delta);
+assert(_vs.high() == high - delta, "invalid expansion");
+}
+}
+bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const {
+assert(p >= _reserved.start(), "just checking");
+size_t delta = pointer_delta(p, _reserved.start());
+return (delta & right_n_bits(LogN_words)) == (size_t)NoBits;
+}
+//////////////////////////////////////////////////////////////////////
+// G1BlockOffsetArray
+//////////////////////////////////////////////////////////////////////
+G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array,
+MemRegion mr, bool init_to_zero) :
+G1BlockOffsetTable(mr.start(), mr.end()),
+_unallocated_block(_bottom),
+_array(array), _csp(NULL),
+_init_to_zero(init_to_zero) {
+assert(_bottom <= _end, "arguments out of order");
+if (!_init_to_zero) {
+// initialize cards to point back to mr.start()
+set_remainder_to_point_to_start(mr.start() + N_words, mr.end());
+_array->set_offset_array(0, 0);  // set first card to 0
+}
+}
+void G1BlockOffsetArray::set_space(Space* sp) {
+_sp = sp;
+_csp = sp->toContiguousSpace();
+}
+// The arguments follow the normal convention of denoting
+// a right-open interval: [start, end)
+void
+G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) {
+if (start >= end) {
+// The start address is equal to the end address (or to
+// the right of the end address) so there are not cards
+// that need to be updated..
+return;
+}
+// Write the backskip value for each region.
+//
+//    offset
+//    card             2nd                       3rd
+//     | +- 1st        |                         |
+//     v v             v                         v
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+-+-
+//    |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ...
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+-+-+-
+//    11              19                        75
+//      12
+//
+//    offset card is the card that points to the start of an object
+//      x - offset value of offset card
+//    1st - start of first logarithmic region
+//      0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1
+//    2nd - start of second logarithmic region
+//      1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8
+//    3rd - start of third logarithmic region
+//      2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64
+//
+//    integer below the block offset entry is an example of
+//    the index of the entry
+//
+//    Given an address,
+//      Find the index for the address
+//      Find the block offset table entry
+//      Convert the entry to a back slide
+//        (e.g., with today's, offset = 0x81 =>
+//          back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8
+//      Move back N (e.g., 8) entries and repeat with the
+//        value of the new entry
+//
+size_t start_card = _array->index_for(start);
+size_t end_card = _array->index_for(end-1);
+assert(start ==_array->address_for_index(start_card), "Precondition");
+assert(end ==_array->address_for_index(end_card)+N_words, "Precondition");
+set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval
+}
+// Unlike the normal convention in this code, the argument here denotes
+// a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start()
+// above.
+void
+G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) {
+if (start_card > end_card) {
+return;
+}
+assert(start_card > _array->index_for(_bottom), "Cannot be first card");
+assert(_array->offset_array(start_card-1) <= N_words,
+"Offset card has an unexpected value");
+size_t start_card_for_region = start_card;
+u_char offset = max_jubyte;
+for (int i = 0; i < BlockOffsetArray::N_powers; i++) {
+// -1 so that the the card with the actual offset is counted.  Another -1
+// so that the reach ends in this region and not at the start
+// of the next.
+size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1);
+offset = N_words + i;
+if (reach >= end_card) {
+_array->set_offset_array(start_card_for_region, end_card, offset);
+start_card_for_region = reach + 1;
+break;
+}
+_array->set_offset_array(start_card_for_region, reach, offset);
+start_card_for_region = reach + 1;
+}
+assert(start_card_for_region > end_card, "Sanity check");
+DEBUG_ONLY(check_all_cards(start_card, end_card);)
+}
+// The block [blk_start, blk_end) has been allocated;
+// adjust the block offset table to represent this information;
+// right-open interval: [blk_start, blk_end)
+void
+G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) {
+mark_block(blk_start, blk_end);
+allocated(blk_start, blk_end);
+}
+// Adjust BOT to show that a previously whole block has been split
+// into two.
+void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size,
+size_t left_blk_size) {
+// Verify that the BOT shows [blk, blk + blk_size) to be one block.
+verify_single_block(blk, blk_size);
+// Update the BOT to indicate that [blk + left_blk_size, blk + blk_size)
+// is one single block.
+mark_block(blk + left_blk_size, blk + blk_size);
+}
+// Action_mark - update the BOT for the block [blk_start, blk_end).
+//               Current typical use is for splitting a block.
+// Action_single - udpate the BOT for an allocation.
+// Action_verify - BOT verification.
+void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start,
+HeapWord* blk_end,
+Action action) {
+assert(Universe::heap()->is_in_reserved(blk_start),
+"reference must be into the heap");
+assert(Universe::heap()->is_in_reserved(blk_end-1),
+"limit must be within the heap");
+// This is optimized to make the test fast, assuming we only rarely
+// cross boundaries.
+uintptr_t end_ui = (uintptr_t)(blk_end - 1);
+uintptr_t start_ui = (uintptr_t)blk_start;
+// Calculate the last card boundary preceding end of blk
+intptr_t boundary_before_end = (intptr_t)end_ui;
+clear_bits(boundary_before_end, right_n_bits(LogN));
+if (start_ui <= (uintptr_t)boundary_before_end) {
+// blk starts at or crosses a boundary
+// Calculate index of card on which blk begins
+size_t    start_index = _array->index_for(blk_start);
+// Index of card on which blk ends
+size_t    end_index   = _array->index_for(blk_end - 1);
+// Start address of card on which blk begins
+HeapWord* boundary    = _array->address_for_index(start_index);
+assert(boundary <= blk_start, "blk should start at or after boundary");
+if (blk_start != boundary) {
+// blk starts strictly after boundary
+// adjust card boundary and start_index forward to next card
+boundary += N_words;
+start_index++;
+}
+assert(start_index <= end_index, "monotonicity of index_for()");
+assert(boundary <= (HeapWord*)boundary_before_end, "tautology");
+switch (action) {
+case Action_mark: {
+if (init_to_zero()) {
+_array->set_offset_array(start_index, boundary, blk_start);
+break;
+} // Else fall through to the next case
+}
+case Action_single: {
+_array->set_offset_array(start_index, boundary, blk_start);
+// We have finished marking the "offset card". We need to now
+// mark the subsequent cards that this blk spans.
+if (start_index < end_index) {
+HeapWord* rem_st = _array->address_for_index(start_index) + N_words;
+HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
+set_remainder_to_point_to_start(rem_st, rem_end);
+}
+break;
+}
+case Action_check: {
+_array->check_offset_array(start_index, boundary, blk_start);
+// We have finished checking the "offset card". We need to now
+// check the subsequent cards that this blk spans.
+check_all_cards(start_index + 1, end_index);
+break;
+}
+default:
+ShouldNotReachHere();
+}
+}
+}
+// The card-interval [start_card, end_card] is a closed interval; this
+// is an expensive check -- use with care and only under protection of
+// suitable flag.
+void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const {
+if (end_card < start_card) {
+return;
+}
+guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card");
+for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) {
+u_char entry = _array->offset_array(c);
+if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) {
+guarantee(entry > N_words, "Should be in logarithmic region");
+}
+size_t backskip = BlockOffsetArray::entry_to_cards_back(entry);
+size_t landing_card = c - backskip;
+guarantee(landing_card >= (start_card - 1), "Inv");
+if (landing_card >= start_card) {
+guarantee(_array->offset_array(landing_card) <= entry, "monotonicity");
+} else {
+guarantee(landing_card == start_card - 1, "Tautology");
+guarantee(_array->offset_array(landing_card) <= N_words, "Offset value");
+}
+}
+}
+// The range [blk_start, blk_end) represents a single contiguous block
+// of storage; modify the block offset table to represent this
+// information; Right-open interval: [blk_start, blk_end)
+// NOTE: this method does _not_ adjust _unallocated_block.
+void
+G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) {
+do_block_internal(blk_start, blk_end, Action_single);
+}
+// Mark the BOT such that if [blk_start, blk_end) straddles a card
+// boundary, the card following the first such boundary is marked
+// with the appropriate offset.
+// NOTE: this method does _not_ adjust _unallocated_block or
+// any cards subsequent to the first one.
+void
+G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) {
+do_block_internal(blk_start, blk_end, Action_mark);
+}
+void G1BlockOffsetArray::join_blocks(HeapWord* blk1, HeapWord* blk2) {
+HeapWord* blk1_start = Universe::heap()->block_start(blk1);
+HeapWord* blk2_start = Universe::heap()->block_start(blk2);
+assert(blk1 == blk1_start && blk2 == blk2_start,
+"Must be block starts.");
+assert(blk1 + _sp->block_size(blk1) == blk2, "Must be contiguous.");
+size_t blk1_start_index = _array->index_for(blk1);
+size_t blk2_start_index = _array->index_for(blk2);
+assert(blk1_start_index <= blk2_start_index, "sanity");
+HeapWord* blk2_card_start = _array->address_for_index(blk2_start_index);
+if (blk2 == blk2_card_start) {
+// blk2 starts a card.  Does blk1 start on the prevous card, or futher
+// back?
+assert(blk1_start_index < blk2_start_index, "must be lower card.");
+if (blk1_start_index + 1 == blk2_start_index) {
+// previous card; new value for blk2 card is size of blk1.
+_array->set_offset_array(blk2_start_index, (u_char) _sp->block_size(blk1));
+} else {
+// Earlier card; go back a card.
+_array->set_offset_array(blk2_start_index, N_words);
+}
+} else {
+// blk2 does not start a card.  Does it cross a card?  If not, nothing
+// to do.
+size_t blk2_end_index =
+_array->index_for(blk2 + _sp->block_size(blk2) - 1);
+assert(blk2_end_index >= blk2_start_index, "sanity");
+if (blk2_end_index > blk2_start_index) {
+// Yes, it crosses a card.  The value for the next card must change.
+if (blk1_start_index + 1 == blk2_start_index) {
+// previous card; new value for second blk2 card is size of blk1.
+_array->set_offset_array(blk2_start_index + 1,
+(u_char) _sp->block_size(blk1));
+} else {
+// Earlier card; go back a card.
+_array->set_offset_array(blk2_start_index + 1, N_words);
+}
+}
+}
+}
+HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) {
+assert(_bottom <= addr && addr < _end,
+"addr must be covered by this Array");
+// Must read this exactly once because it can be modified by parallel
+// allocation.
+HeapWord* ub = _unallocated_block;
+if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
+assert(ub < _end, "tautology (see above)");
+return ub;
+}
+// Otherwise, find the block start using the table.
+HeapWord* q = block_at_or_preceding(addr, false, 0);
+return forward_to_block_containing_addr(q, addr);
+}
+// This duplicates a little code from the above: unavoidable.
+HeapWord*
+G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const {
+assert(_bottom <= addr && addr < _end,
+"addr must be covered by this Array");
+// Must read this exactly once because it can be modified by parallel
+// allocation.
+HeapWord* ub = _unallocated_block;
+if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
+assert(ub < _end, "tautology (see above)");
+return ub;
+}
+// Otherwise, find the block start using the table.
+HeapWord* q = block_at_or_preceding(addr, false, 0);
+HeapWord* n = q + _sp->block_size(q);
+return forward_to_block_containing_addr_const(q, n, addr);
+}
+HeapWord*
+G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q,
+HeapWord* n,
+const void* addr) {
+// We're not in the normal case.  We need to handle an important subcase
+// here: LAB allocation.  An allocation previously recorded in the
+// offset table was actually a lab allocation, and was divided into
+// several objects subsequently.  Fix this situation as we answer the
+// query, by updating entries as we cross them.
+size_t next_index = _array->index_for(n) + 1;
+HeapWord* next_boundary = _array->address_for_index(next_index);
+if (csp() != NULL) {
+if (addr >= csp()->top()) return csp()->top();
+while (next_boundary < addr) {
+while (n <= next_boundary) {
+q = n;
+oop obj = oop(q);
+if (obj->klass() == NULL) return q;
+n += obj->size();
+}
+assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
+// [q, n) is the block that crosses the boundary.
+alloc_block_work2(&next_boundary, &next_index, q, n);
+}
+} else {
+while (next_boundary < addr) {
+while (n <= next_boundary) {
+q = n;
+oop obj = oop(q);
+if (obj->klass() == NULL) return q;
+n += _sp->block_size(q);
+}
+assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
+// [q, n) is the block that crosses the boundary.
+alloc_block_work2(&next_boundary, &next_index, q, n);
+}
+}
+return forward_to_block_containing_addr_const(q, n, addr);
+}
+HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const {
+assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
+assert(_bottom <= addr && addr < _end,
+"addr must be covered by this Array");
+// Must read this exactly once because it can be modified by parallel
+// allocation.
+HeapWord* ub = _unallocated_block;
+if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
+assert(ub < _end, "tautology (see above)");
+return ub;
+}
+// Otherwise, find the block start using the table, but taking
+// care (cf block_start_unsafe() above) not to parse any objects/blocks
+// on the cards themsleves.
+size_t index = _array->index_for(addr);
+assert(_array->address_for_index(index) == addr,
+"arg should be start of card");
+HeapWord* q = (HeapWord*)addr;
+uint offset;
+do {
+offset = _array->offset_array(index--);
+q -= offset;
+} while (offset == N_words);
+assert(q <= addr, "block start should be to left of arg");
+return q;
+}
+// Note that the committed size of the covered space may have changed,
+// so the table size might also wish to change.
+void G1BlockOffsetArray::resize(size_t new_word_size) {
+HeapWord* new_end = _bottom + new_word_size;
+if (_end < new_end && !init_to_zero()) {
+// verify that the old and new boundaries are also card boundaries
+assert(_array->is_card_boundary(_end),
+"_end not a card boundary");
+assert(_array->is_card_boundary(new_end),
+"new _end would not be a card boundary");
+// set all the newly added cards
+_array->set_offset_array(_end, new_end, N_words);
+}
+_end = new_end;  // update _end
+}
+void G1BlockOffsetArray::set_region(MemRegion mr) {
+_bottom = mr.start();
+_end = mr.end();
+}
+//
+//              threshold_
+//              |   _index_
+//              v   v
+//      +-------+-------+-------+-------+-------+
+//      | i-1   |   i   | i+1   | i+2   | i+3   |
+//      +-------+-------+-------+-------+-------+
+//       ( ^    ]
+//         block-start
+//
+void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_,
+HeapWord* blk_start, HeapWord* blk_end) {
+// For efficiency, do copy-in/copy-out.
+HeapWord* threshold = *threshold_;
+size_t    index = *index_;
+assert(blk_start != NULL && blk_end > blk_start,
+"phantom block");
+assert(blk_end > threshold, "should be past threshold");
+assert(blk_start <= threshold, "blk_start should be at or before threshold")
+assert(pointer_delta(threshold, blk_start) <= N_words,
+"offset should be <= BlockOffsetSharedArray::N");
+assert(Universe::heap()->is_in_reserved(blk_start),
+"reference must be into the heap");
+assert(Universe::heap()->is_in_reserved(blk_end-1),
+"limit must be within the heap");
+assert(threshold == _array->_reserved.start() + index*N_words,
+"index must agree with threshold");
+DEBUG_ONLY(size_t orig_index = index;)
+// Mark the card that holds the offset into the block.  Note
+// that _next_offset_index and _next_offset_threshold are not
+// updated until the end of this method.
+_array->set_offset_array(index, threshold, blk_start);
+// We need to now mark the subsequent cards that this blk spans.
+// Index of card on which blk ends.
+size_t end_index   = _array->index_for(blk_end - 1);
+// Are there more cards left to be updated?
+if (index + 1 <= end_index) {
+HeapWord* rem_st  = _array->address_for_index(index + 1);
+// Calculate rem_end this way because end_index
+// may be the last valid index in the covered region.
+HeapWord* rem_end = _array->address_for_index(end_index) +  N_words;
+set_remainder_to_point_to_start(rem_st, rem_end);
+}
+index = end_index + 1;
+// Calculate threshold_ this way because end_index
+// may be the last valid index in the covered region.
+threshold = _array->address_for_index(end_index) + N_words;
+assert(threshold >= blk_end, "Incorrect offset threshold");
+// index_ and threshold_ updated here.
+*threshold_ = threshold;
+*index_ = index;
+#ifdef ASSERT
+// The offset can be 0 if the block starts on a boundary.  That
+// is checked by an assertion above.
+size_t start_index = _array->index_for(blk_start);
+HeapWord* boundary    = _array->address_for_index(start_index);
+assert((_array->offset_array(orig_index) == 0 &&
+blk_start == boundary) ||
+(_array->offset_array(orig_index) > 0 &&
+_array->offset_array(orig_index) <= N_words),
+"offset array should have been set");
+for (size_t j = orig_index + 1; j <= end_index; j++) {
+assert(_array->offset_array(j) > 0 &&
+_array->offset_array(j) <=
+(u_char) (N_words+BlockOffsetArray::N_powers-1),
+"offset array should have been set");
+}
+#endif
+}
+//////////////////////////////////////////////////////////////////////
+// G1BlockOffsetArrayContigSpace
+//////////////////////////////////////////////////////////////////////
+HeapWord*
+G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) {
+assert(_bottom <= addr && addr < _end,
+"addr must be covered by this Array");
+HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
+return forward_to_block_containing_addr(q, addr);
+}
+HeapWord*
+G1BlockOffsetArrayContigSpace::
+block_start_unsafe_const(const void* addr) const {
+assert(_bottom <= addr && addr < _end,
+"addr must be covered by this Array");
+HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
+HeapWord* n = q + _sp->block_size(q);
+return forward_to_block_containing_addr_const(q, n, addr);
+}
+G1BlockOffsetArrayContigSpace::
+G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array,
+MemRegion mr) :
+G1BlockOffsetArray(array, mr, true)
+{
+_next_offset_threshold = NULL;
+_next_offset_index = 0;
+}
+HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() {
+assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
+"just checking");
+_next_offset_index = _array->index_for(_bottom);
+_next_offset_index++;
+_next_offset_threshold =
+_array->address_for_index(_next_offset_index);
+return _next_offset_threshold;
+}
+void G1BlockOffsetArrayContigSpace::zero_bottom_entry() {
+assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
+"just checking");
+size_t bottom_index = _array->index_for(_bottom);
+assert(_array->address_for_index(bottom_index) == _bottom,
+"Precondition of call");
+_array->set_offset_array(bottom_index, 0);
+}

Mercurial > hg > graal-compiler

comparison src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp @ 342:37f87013dfd8