jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@caac22686b17 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@caac22686b17 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp

Mon, 29 Apr 2013 09:31:59 +0200

author: mgerdin
date: Mon, 29 Apr 2013 09:31:59 +0200
changeset 5022: caac22686b17
parent 3900: d2a62e0f25eb
child 5074: b0d20fa374b4
permissions: -rw-r--r--

Merge

 /*
  * 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/heapRegion.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "gc_implementation/g1/heapRegionSets.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "memory/allocation.hpp"
 // Private
 uint HeapRegionSeq::find_contiguous_from(uint from, uint num) {
   uint len = length();
   assert(num > 1, "use this only for sequences of length 2 or greater");
   assert(from <= len,
          err_msg("from: %u should be valid and <= than %u", from, len));
   uint curr = from;
   uint first = G1_NULL_HRS_INDEX;
   uint num_so_far = 0;
   while (curr < len && num_so_far < num) {
     if (at(curr)->is_empty()) {
       if (first == G1_NULL_HRS_INDEX) {
         first = curr;
         num_so_far = 1;
       } else {
         num_so_far += 1;
       }
     } else {
       first = G1_NULL_HRS_INDEX;
       num_so_far = 0;
     }
     curr += 1;
   }
   assert(num_so_far <= num, "post-condition");
   if (num_so_far == num) {
     // we found enough space for the humongous object
     assert(from <= first && first < len, "post-condition");
     assert(first < curr && (curr - first) == num, "post-condition");
     for (uint i = first; i < first + num; ++i) {
       assert(at(i)->is_empty(), "post-condition");
     }
     return first;
   } else {
     // we failed to find enough space for the humongous object
     return G1_NULL_HRS_INDEX;
   }
 }
 // Public
 void HeapRegionSeq::initialize(HeapWord* bottom, HeapWord* end,
                                uint max_length) {
   assert((uintptr_t) bottom % HeapRegion::GrainBytes == 0,
          "bottom should be heap region aligned");
   assert((uintptr_t) end % HeapRegion::GrainBytes == 0,
          "end should be heap region aligned");
   _length = 0;
   _heap_bottom = bottom;
   _heap_end = end;
   _region_shift = HeapRegion::LogOfHRGrainBytes;
   _next_search_index = 0;
   _allocated_length = 0;
   _max_length = max_length;
   _regions = NEW_C_HEAP_ARRAY(HeapRegion*, max_length, mtGC);
   memset(_regions, 0, (size_t) max_length * sizeof(HeapRegion*));
   _regions_biased = _regions - ((uintx) bottom >> _region_shift);
   assert(&_regions[0] == &_regions_biased[addr_to_index_biased(bottom)],
          "bottom should be included in the region with index 0");
 }
 MemRegion HeapRegionSeq::expand_by(HeapWord* old_end,
                                    HeapWord* new_end,
                                    FreeRegionList* list) {
   assert(old_end < new_end, "don't call it otherwise");
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   HeapWord* next_bottom = old_end;
   assert(_heap_bottom <= next_bottom, "invariant");
   while (next_bottom < new_end) {
     assert(next_bottom < _heap_end, "invariant");
     uint index = length();
     assert(index < _max_length, "otherwise we cannot expand further");
     if (index == 0) {
       // We have not allocated any regions so far
       assert(next_bottom == _heap_bottom, "invariant");
     } else {
       // next_bottom should match the end of the last/previous region
       assert(next_bottom == at(index - 1)->end(), "invariant");
     }
     if (index == _allocated_length) {
       // We have to allocate a new HeapRegion.
       HeapRegion* new_hr = g1h->new_heap_region(index, next_bottom);
       if (new_hr == NULL) {
         // allocation failed, we bail out and return what we have done so far
         return MemRegion(old_end, next_bottom);
       }
       assert(_regions[index] == NULL, "invariant");
       _regions[index] = new_hr;
       increment_length(&_allocated_length);
     }
     // Have to increment the length first, otherwise we will get an
     // assert failure at(index) below.
     increment_length(&_length);
     HeapRegion* hr = at(index);
     list->add_as_tail(hr);
     next_bottom = hr->end();
   }
   assert(next_bottom == new_end, "post-condition");
   return MemRegion(old_end, next_bottom);
 }
 uint HeapRegionSeq::free_suffix() {
   uint res = 0;
   uint index = length();
   while (index > 0) {
     index -= 1;
     if (!at(index)->is_empty()) {
       break;
     }
     res += 1;
   }
   return res;
 }
 uint HeapRegionSeq::find_contiguous(uint num) {
   assert(num > 1, "use this only for sequences of length 2 or greater");
   assert(_next_search_index <= length(),
          err_msg("_next_search_index: %u should be valid and <= than %u",
                  _next_search_index, length()));
   uint start = _next_search_index;
   uint res = find_contiguous_from(start, num);
   if (res == G1_NULL_HRS_INDEX && start > 0) {
     // Try starting from the beginning. If _next_search_index was 0,
     // no point in doing this again.
     res = find_contiguous_from(0, num);
   }
   if (res != G1_NULL_HRS_INDEX) {
     assert(res < length(), err_msg("res: %u should be valid", res));
     _next_search_index = res + num;
     assert(_next_search_index <= length(),
            err_msg("_next_search_index: %u should be valid and <= than %u",
                    _next_search_index, length()));
   }
   return res;
 }
 void HeapRegionSeq::iterate(HeapRegionClosure* blk) const {
   iterate_from((HeapRegion*) NULL, blk);
 }
 void HeapRegionSeq::iterate_from(HeapRegion* hr, HeapRegionClosure* blk) const {
   uint hr_index = 0;
   if (hr != NULL) {
     hr_index = hr->hrs_index();
   }
   uint len = length();
   for (uint i = hr_index; i < len; i += 1) {
     bool res = blk->doHeapRegion(at(i));
     if (res) {
       blk->incomplete();
       return;
     }
   }
   for (uint i = 0; i < hr_index; i += 1) {
     bool res = blk->doHeapRegion(at(i));
     if (res) {
       blk->incomplete();
       return;
     }
   }
 }
 MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes,
                                    uint* num_regions_deleted) {
   // Reset this in case it's currently pointing into the regions that
   // we just removed.
   _next_search_index = 0;
   assert(shrink_bytes % os::vm_page_size() == 0, "unaligned");
   assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned");
   assert(length() > 0, "the region sequence should not be empty");
   assert(length() <= _allocated_length, "invariant");
   assert(_allocated_length > 0, "we should have at least one region committed");
   // around the loop, i will be the next region to be removed
   uint i = length() - 1;
   assert(i > 0, "we should never remove all regions");
   // [last_start, end) is the MemRegion that covers the regions we will remove.
   HeapWord* end = at(i)->end();
   HeapWord* last_start = end;
   *num_regions_deleted = 0;
   while (shrink_bytes > 0) {
     HeapRegion* cur = at(i);
     // We should leave the humongous regions where they are.
     if (cur->isHumongous()) break;
     // We should stop shrinking if we come across a non-empty region.
     if (!cur->is_empty()) break;
     i -= 1;
     *num_regions_deleted += 1;
     shrink_bytes -= cur->capacity();
     last_start = cur->bottom();
     decrement_length(&_length);
     // We will reclaim the HeapRegion. _allocated_length should be
     // covering this index. So, even though we removed the region from
     // the active set by decreasing _length, we still have it
     // available in the future if we need to re-use it.
     assert(i > 0, "we should never remove all regions");
     assert(length() > 0, "we should never remove all regions");
   }
   return MemRegion(last_start, end);
 }
 #ifndef PRODUCT
 void HeapRegionSeq::verify_optional() {
   guarantee(_length <= _allocated_length,
             err_msg("invariant: _length: %u _allocated_length: %u",
                     _length, _allocated_length));
   guarantee(_allocated_length <= _max_length,
             err_msg("invariant: _allocated_length: %u _max_length: %u",
                     _allocated_length, _max_length));
   guarantee(_next_search_index <= _length,
             err_msg("invariant: _next_search_index: %u _length: %u",
                     _next_search_index, _length));
   HeapWord* prev_end = _heap_bottom;
   for (uint i = 0; i < _allocated_length; i += 1) {
     HeapRegion* hr = _regions[i];
     guarantee(hr != NULL, err_msg("invariant: i: %u", i));
     guarantee(hr->bottom() == prev_end,
               err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT,
                       i, HR_FORMAT_PARAMS(hr), prev_end));
     guarantee(hr->hrs_index() == i,
               err_msg("invariant: i: %u hrs_index(): %u", i, hr->hrs_index()));
     if (i < _length) {
       // Asserts will fire if i is >= _length
       HeapWord* addr = hr->bottom();
       guarantee(addr_to_region(addr) == hr, "sanity");
       guarantee(addr_to_region_unsafe(addr) == hr, "sanity");
     } else {
       guarantee(hr->is_empty(), "sanity");
       guarantee(!hr->isHumongous(), "sanity");
       // using assert instead of guarantee here since containing_set()
       // is only available in non-product builds.
       assert(hr->containing_set() == NULL, "sanity");
     }
     if (hr->startsHumongous()) {
       prev_end = hr->orig_end();
     } else {
       prev_end = hr->end();
     }
   }
   for (uint i = _allocated_length; i < _max_length; i += 1) {
     guarantee(_regions[i] == NULL, err_msg("invariant i: %u", i));
   }
 }
 #endif // PRODUCT

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@caac22686b17 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp