jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@2d160770d2e5 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@2d160770d2e5 (annotated)

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

Mon, 02 Aug 2010 12:51:43 -0700

author: johnc
date: Mon, 02 Aug 2010 12:51:43 -0700
changeset 2060: 2d160770d2e5
parent 1907: c18cbe5936b8
child 2043: 2dfd013a7465
permissions: -rw-r--r--

6814437: G1: remove the _new_refs array
Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp

 /*
  * Copyright (c) 2001, 2009, 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 "incls/_precompiled.incl"
 #include "incls/_heapRegionSeq.cpp.incl"
 // Local to this file.
 static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
   if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1;
   else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1;
   else if (*hr1p == *hr2p) return 0;
   else {
     assert(false, "We should never compare distinct overlapping regions.");
   }
   return 0;
 }
 HeapRegionSeq::HeapRegionSeq(const size_t max_size) :
   _alloc_search_start(0),
   // The line below is the worst bit of C++ hackery I've ever written
   // (Detlefs, 11/23).  You should think of it as equivalent to
   // "_regions(100, true)": initialize the growable array and inform it
   // that it should allocate its elem array(s) on the C heap.  The first
   // argument, however, is actually a comma expression (new-expr, 100).
   // The purpose of the new_expr is to inform the growable array that it
   // is *already* allocated on the C heap: it uses the placement syntax to
   // keep it from actually doing any allocation.
   _regions((ResourceObj::operator new (sizeof(GrowableArray<HeapRegion*>),
                                        (void*)&_regions,
                                        ResourceObj::C_HEAP),
             (int)max_size),
            true),
   _next_rr_candidate(0),
   _seq_bottom(NULL)
 {}
 // Private methods.
 HeapWord*
 HeapRegionSeq::alloc_obj_from_region_index(int ind, size_t word_size) {
   assert(G1CollectedHeap::isHumongous(word_size),
          "Allocation size should be humongous");
   int cur = ind;
   int first = cur;
   size_t sumSizes = 0;
   while (cur < _regions.length() && sumSizes < word_size) {
     // Loop invariant:
     //  For all i in [first, cur):
     //       _regions.at(i)->is_empty()
     //    && _regions.at(i) is contiguous with its predecessor, if any
     //  && sumSizes is the sum of the sizes of the regions in the interval
     //       [first, cur)
     HeapRegion* curhr = _regions.at(cur);
     if (curhr->is_empty()
         && (first == cur
             || (_regions.at(cur-1)->end() ==
                 curhr->bottom()))) {
       sumSizes += curhr->capacity() / HeapWordSize;
     } else {
       first = cur + 1;
       sumSizes = 0;
     }
     cur++;
   }
   if (sumSizes >= word_size) {
     _alloc_search_start = cur;
     // Mark the allocated regions as allocated.
     bool zf = G1CollectedHeap::heap()->allocs_are_zero_filled();
     HeapRegion* first_hr = _regions.at(first);
     for (int i = first; i < cur; i++) {
       HeapRegion* hr = _regions.at(i);
       if (zf)
         hr->ensure_zero_filled();
       {
         MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
         hr->set_zero_fill_allocated();
       }
       size_t sz = hr->capacity() / HeapWordSize;
       HeapWord* tmp = hr->allocate(sz);
       assert(tmp != NULL, "Humongous allocation failure");
       MemRegion mr = MemRegion(tmp, sz);
       CollectedHeap::fill_with_object(mr);
       hr->declare_filled_region_to_BOT(mr);
       if (i == first) {
         first_hr->set_startsHumongous();
       } else {
         assert(i > first, "sanity");
         hr->set_continuesHumongous(first_hr);
       }
     }
     HeapWord* first_hr_bot = first_hr->bottom();
     HeapWord* obj_end = first_hr_bot + word_size;
     first_hr->set_top(obj_end);
     return first_hr_bot;
   } else {
     // If we started from the beginning, we want to know why we can't alloc.
     return NULL;
   }
 }
 void HeapRegionSeq::print_empty_runs() {
   int empty_run = 0;
   int n_empty = 0;
   int empty_run_start;
   for (int i = 0; i < _regions.length(); i++) {
     HeapRegion* r = _regions.at(i);
     if (r->continuesHumongous()) continue;
     if (r->is_empty()) {
       assert(!r->isHumongous(), "H regions should not be empty.");
       if (empty_run == 0) empty_run_start = i;
       empty_run++;
       n_empty++;
     } else {
       if (empty_run > 0) {
         gclog_or_tty->print("  %d:%d", empty_run_start, empty_run);
         empty_run = 0;
       }
     }
   }
   if (empty_run > 0) {
     gclog_or_tty->print(" %d:%d", empty_run_start, empty_run);
   }
   gclog_or_tty->print_cr(" [tot = %d]", n_empty);
 }
 int HeapRegionSeq::find(HeapRegion* hr) {
   // FIXME: optimized for adjacent regions of fixed size.
   int ind = hr->hrs_index();
   if (ind != -1) {
     assert(_regions.at(ind) == hr, "Mismatch");
   }
   return ind;
 }
 // Public methods.
 void HeapRegionSeq::insert(HeapRegion* hr) {
   assert(!_regions.is_full(), "Too many elements in HeapRegionSeq");
   if (_regions.length() == 0
       || _regions.top()->end() <= hr->bottom()) {
     hr->set_hrs_index(_regions.length());
     _regions.append(hr);
   } else {
     _regions.append(hr);
     _regions.sort(orderRegions);
     for (int i = 0; i < _regions.length(); i++) {
       _regions.at(i)->set_hrs_index(i);
     }
   }
   char* bot = (char*)_regions.at(0)->bottom();
   if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot;
 }
 size_t HeapRegionSeq::length() {
   return _regions.length();
 }
 size_t HeapRegionSeq::free_suffix() {
   size_t res = 0;
   int first = _regions.length() - 1;
   int cur = first;
   while (cur >= 0 &&
          (_regions.at(cur)->is_empty()
           && (first == cur
               || (_regions.at(cur+1)->bottom() ==
                   _regions.at(cur)->end())))) {
       res++;
       cur--;
   }
   return res;
 }
 HeapWord* HeapRegionSeq::obj_allocate(size_t word_size) {
   int cur = _alloc_search_start;
   // Make sure "cur" is a valid index.
   assert(cur >= 0, "Invariant.");
   HeapWord* res = alloc_obj_from_region_index(cur, word_size);
   if (res == NULL)
     res = alloc_obj_from_region_index(0, word_size);
   return res;
 }
 void HeapRegionSeq::iterate(HeapRegionClosure* blk) {
   iterate_from((HeapRegion*)NULL, blk);
 }
 // The first argument r is the heap region at which iteration begins.
 // This operation runs fastest when r is NULL, or the heap region for
 // which a HeapRegionClosure most recently returned true, or the
 // heap region immediately to its right in the sequence.  In all
 // other cases a linear search is required to find the index of r.
 void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) {
   // :::: FIXME ::::
   // Static cache value is bad, especially when we start doing parallel
   // remembered set update. For now just don't cache anything (the
   // code in the def'd out blocks).
 #if 0
   static int cached_j = 0;
 #endif
   int len = _regions.length();
   int j = 0;
   // Find the index of r.
   if (r != NULL) {
 #if 0
     assert(cached_j >= 0, "Invariant.");
     if ((cached_j < len) && (r == _regions.at(cached_j))) {
       j = cached_j;
     } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) {
       j = cached_j + 1;
     } else {
       j = find(r);
 #endif
       if (j < 0) {
         j = 0;
       }
 #if 0
     }
 #endif
   }
   int i;
   for (i = j; i < len; i += 1) {
     int res = blk->doHeapRegion(_regions.at(i));
     if (res) {
 #if 0
       cached_j = i;
 #endif
       blk->incomplete();
       return;
     }
   }
   for (i = 0; i < j; i += 1) {
     int res = blk->doHeapRegion(_regions.at(i));
     if (res) {
 #if 0
       cached_j = i;
 #endif
       blk->incomplete();
       return;
     }
   }
 }
 void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) {
   int len = _regions.length();
   int i;
   for (i = idx; i < len; i++) {
     if (blk->doHeapRegion(_regions.at(i))) {
       blk->incomplete();
       return;
     }
   }
   for (i = 0; i < idx; i++) {
     if (blk->doHeapRegion(_regions.at(i))) {
       blk->incomplete();
       return;
     }
   }
 }
 MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes,
                                    size_t& num_regions_deleted) {
   assert(shrink_bytes % os::vm_page_size() == 0, "unaligned");
   assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned");
   if (_regions.length() == 0) {
     num_regions_deleted = 0;
     return MemRegion();
   }
   int j = _regions.length() - 1;
   HeapWord* end = _regions.at(j)->end();
   HeapWord* last_start = end;
   while (j >= 0 && shrink_bytes > 0) {
     HeapRegion* cur = _regions.at(j);
     // We have to leave humongous regions where they are,
     // and work around them.
     if (cur->isHumongous()) {
       return MemRegion(last_start, end);
     }
     assert(cur == _regions.top(), "Should be top");
     if (!cur->is_empty()) break;
     cur->reset_zero_fill();
     shrink_bytes -= cur->capacity();
     num_regions_deleted++;
     _regions.pop();
     last_start = cur->bottom();
     // We need to delete these somehow, but can't currently do so here: if
     // we do, the ZF thread may still access the deleted region.  We'll
     // leave this here as a reminder that we have to do something about
     // this.
     // delete cur;
     j--;
   }
   return MemRegion(last_start, end);
 }
 class PrintHeapRegionClosure : public  HeapRegionClosure {
 public:
   bool doHeapRegion(HeapRegion* r) {
     gclog_or_tty->print(PTR_FORMAT ":", r);
     r->print();
     return false;
   }
 };
 void HeapRegionSeq::print() {
   PrintHeapRegionClosure cl;
   iterate(&cl);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp@2d160770d2e5 (annotated)

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