jdk8-mips64-public/hotspot: src/share/vm/memory/generation.cpp@2958af1d8c5a (annotated)

src/share/vm/memory/generation.cpp@2958af1d8c5a (annotated)

src/share/vm/memory/generation.cpp

Fri, 17 May 2013 06:01:10 +0200

author: jwilhelm
date: Fri, 17 May 2013 06:01:10 +0200
changeset 5125: 2958af1d8c5a
parent 4900: 8617e38bb4cb
child 5237: f2110083203d
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1997, 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/shared/spaceDecorator.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/blockOffsetTable.inline.hpp"
 #include "memory/cardTableRS.hpp"
 #include "memory/gcLocker.inline.hpp"
 #include "memory/genCollectedHeap.hpp"
 #include "memory/genMarkSweep.hpp"
 #include "memory/genOopClosures.hpp"
 #include "memory/genOopClosures.inline.hpp"
 #include "memory/generation.hpp"
 #include "memory/generation.inline.hpp"
 #include "memory/space.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/java.hpp"
 #include "utilities/copy.hpp"
 #include "utilities/events.hpp"
 Generation::Generation(ReservedSpace rs, size_t initial_size, int level) :
   _level(level),
   _ref_processor(NULL) {
   if (!_virtual_space.initialize(rs, initial_size)) {
     vm_exit_during_initialization("Could not reserve enough space for "
                     "object heap");
   }
   // Mangle all of the the initial generation.
   if (ZapUnusedHeapArea) {
     MemRegion mangle_region((HeapWord*)_virtual_space.low(),
       (HeapWord*)_virtual_space.high());
     SpaceMangler::mangle_region(mangle_region);
   }
   _reserved = MemRegion((HeapWord*)_virtual_space.low_boundary(),
           (HeapWord*)_virtual_space.high_boundary());
 }
 GenerationSpec* Generation::spec() {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   assert(0 <= level() && level() < gch->_n_gens, "Bad gen level");
   return gch->_gen_specs[level()];
 }
 size_t Generation::max_capacity() const {
   return reserved().byte_size();
 }
 void Generation::print_heap_change(size_t prev_used) const {
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print(" "  SIZE_FORMAT
                         "->" SIZE_FORMAT
                         "("  SIZE_FORMAT ")",
                         prev_used, used(), capacity());
   } else {
     gclog_or_tty->print(" "  SIZE_FORMAT "K"
                         "->" SIZE_FORMAT "K"
                         "("  SIZE_FORMAT "K)",
                         prev_used / K, used() / K, capacity() / K);
   }
 }
 // By default we get a single threaded default reference processor;
 // generations needing multi-threaded refs processing or discovery override this method.
 void Generation::ref_processor_init() {
   assert(_ref_processor == NULL, "a reference processor already exists");
   assert(!_reserved.is_empty(), "empty generation?");
   _ref_processor = new ReferenceProcessor(_reserved);    // a vanilla reference processor
   if (_ref_processor == NULL) {
     vm_exit_during_initialization("Could not allocate ReferenceProcessor object");
   }
 }
 void Generation::print() const { print_on(tty); }
 void Generation::print_on(outputStream* st)  const {
   st->print(" %-20s", name());
   st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
              capacity()/K, used()/K);
   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
               _virtual_space.low_boundary(),
               _virtual_space.high(),
               _virtual_space.high_boundary());
 }
 void Generation::print_summary_info() { print_summary_info_on(tty); }
 void Generation::print_summary_info_on(outputStream* st) {
   StatRecord* sr = stat_record();
   double time = sr->accumulated_time.seconds();
   st->print_cr("[Accumulated GC generation %d time %3.7f secs, "
                "%d GC's, avg GC time %3.7f]",
                level(), time, sr->invocations,
                sr->invocations > 0 ? time / sr->invocations : 0.0);
 }
 // Utility iterator classes
 class GenerationIsInReservedClosure : public SpaceClosure {
  public:
   const void* _p;
   Space* sp;
   virtual void do_space(Space* s) {
     if (sp == NULL) {
       if (s->is_in_reserved(_p)) sp = s;
     }
   }
   GenerationIsInReservedClosure(const void* p) : _p(p), sp(NULL) {}
 };
 class GenerationIsInClosure : public SpaceClosure {
  public:
   const void* _p;
   Space* sp;
   virtual void do_space(Space* s) {
     if (sp == NULL) {
       if (s->is_in(_p)) sp = s;
     }
   }
   GenerationIsInClosure(const void* p) : _p(p), sp(NULL) {}
 };
 bool Generation::is_in(const void* p) const {
   GenerationIsInClosure blk(p);
   ((Generation*)this)->space_iterate(&blk);
   return blk.sp != NULL;
 }
 DefNewGeneration* Generation::as_DefNewGeneration() {
   assert((kind() == Generation::DefNew) ||
          (kind() == Generation::ParNew) ||
          (kind() == Generation::ASParNew),
     "Wrong youngest generation type");
   return (DefNewGeneration*) this;
 }
 Generation* Generation::next_gen() const {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   int next = level() + 1;
   if (next < gch->_n_gens) {
     return gch->_gens[next];
   } else {
     return NULL;
   }
 }
 size_t Generation::max_contiguous_available() const {
   // The largest number of contiguous free words in this or any higher generation.
   size_t max = 0;
   for (const Generation* gen = this; gen != NULL; gen = gen->next_gen()) {
     size_t avail = gen->contiguous_available();
     if (avail > max) {
       max = avail;
     }
   }
   return max;
 }
 bool Generation::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
   size_t available = max_contiguous_available();
   bool   res = (available >= max_promotion_in_bytes);
   if (PrintGC && Verbose) {
     gclog_or_tty->print_cr(
       "Generation: promo attempt is%s safe: available("SIZE_FORMAT") %s max_promo("SIZE_FORMAT")",
       res? "":" not", available, res? ">=":"<",
       max_promotion_in_bytes);
   }
   return res;
 }
 // Ignores "ref" and calls allocate().
 oop Generation::promote(oop obj, size_t obj_size) {
   assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
 #ifndef PRODUCT
   if (Universe::heap()->promotion_should_fail()) {
     return NULL;
   }
 #endif  // #ifndef PRODUCT
   HeapWord* result = allocate(obj_size, false);
   if (result != NULL) {
     Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
     return oop(result);
   } else {
     GenCollectedHeap* gch = GenCollectedHeap::heap();
     return gch->handle_failed_promotion(this, obj, obj_size);
   }
 }
 oop Generation::par_promote(int thread_num,
                             oop obj, markOop m, size_t word_sz) {
   // Could do a bad general impl here that gets a lock.  But no.
   ShouldNotCallThis();
   return NULL;
 }
 void Generation::par_promote_alloc_undo(int thread_num,
                                         HeapWord* obj, size_t word_sz) {
   // Could do a bad general impl here that gets a lock.  But no.
   guarantee(false, "No good general implementation.");
 }
 Space* Generation::space_containing(const void* p) const {
   GenerationIsInReservedClosure blk(p);
   // Cast away const
   ((Generation*)this)->space_iterate(&blk);
   return blk.sp;
 }
 // Some of these are mediocre general implementations.  Should be
 // overridden to get better performance.
 class GenerationBlockStartClosure : public SpaceClosure {
  public:
   const void* _p;
   HeapWord* _start;
   virtual void do_space(Space* s) {
     if (_start == NULL && s->is_in_reserved(_p)) {
       _start = s->block_start(_p);
     }
   }
   GenerationBlockStartClosure(const void* p) { _p = p; _start = NULL; }
 };
 HeapWord* Generation::block_start(const void* p) const {
   GenerationBlockStartClosure blk(p);
   // Cast away const
   ((Generation*)this)->space_iterate(&blk);
   return blk._start;
 }
 class GenerationBlockSizeClosure : public SpaceClosure {
  public:
   const HeapWord* _p;
   size_t size;
   virtual void do_space(Space* s) {
     if (size == 0 && s->is_in_reserved(_p)) {
       size = s->block_size(_p);
     }
   }
   GenerationBlockSizeClosure(const HeapWord* p) { _p = p; size = 0; }
 };
 size_t Generation::block_size(const HeapWord* p) const {
   GenerationBlockSizeClosure blk(p);
   // Cast away const
   ((Generation*)this)->space_iterate(&blk);
   assert(blk.size > 0, "seems reasonable");
   return blk.size;
 }
 class GenerationBlockIsObjClosure : public SpaceClosure {
  public:
   const HeapWord* _p;
   bool is_obj;
   virtual void do_space(Space* s) {
     if (!is_obj && s->is_in_reserved(_p)) {
       is_obj |= s->block_is_obj(_p);
     }
   }
   GenerationBlockIsObjClosure(const HeapWord* p) { _p = p; is_obj = false; }
 };
 bool Generation::block_is_obj(const HeapWord* p) const {
   GenerationBlockIsObjClosure blk(p);
   // Cast away const
   ((Generation*)this)->space_iterate(&blk);
   return blk.is_obj;
 }
 class GenerationOopIterateClosure : public SpaceClosure {
  public:
   ExtendedOopClosure* cl;
   MemRegion mr;
   virtual void do_space(Space* s) {
     s->oop_iterate(mr, cl);
   }
   GenerationOopIterateClosure(ExtendedOopClosure* _cl, MemRegion _mr) :
     cl(_cl), mr(_mr) {}
 };
 void Generation::oop_iterate(ExtendedOopClosure* cl) {
   GenerationOopIterateClosure blk(cl, _reserved);
   space_iterate(&blk);
 }
 void Generation::oop_iterate(MemRegion mr, ExtendedOopClosure* cl) {
   GenerationOopIterateClosure blk(cl, mr);
   space_iterate(&blk);
 }
 void Generation::younger_refs_in_space_iterate(Space* sp,
                                                OopsInGenClosure* cl) {
   GenRemSet* rs = SharedHeap::heap()->rem_set();
   rs->younger_refs_in_space_iterate(sp, cl);
 }
 class GenerationObjIterateClosure : public SpaceClosure {
  private:
   ObjectClosure* _cl;
  public:
   virtual void do_space(Space* s) {
     s->object_iterate(_cl);
   }
   GenerationObjIterateClosure(ObjectClosure* cl) : _cl(cl) {}
 };
 void Generation::object_iterate(ObjectClosure* cl) {
   GenerationObjIterateClosure blk(cl);
   space_iterate(&blk);
 }
 class GenerationSafeObjIterateClosure : public SpaceClosure {
  private:
   ObjectClosure* _cl;
  public:
   virtual void do_space(Space* s) {
     s->safe_object_iterate(_cl);
   }
   GenerationSafeObjIterateClosure(ObjectClosure* cl) : _cl(cl) {}
 };
 void Generation::safe_object_iterate(ObjectClosure* cl) {
   GenerationSafeObjIterateClosure blk(cl);
   space_iterate(&blk);
 }
 void Generation::prepare_for_compaction(CompactPoint* cp) {
   // Generic implementation, can be specialized
   CompactibleSpace* space = first_compaction_space();
   while (space != NULL) {
     space->prepare_for_compaction(cp);
     space = space->next_compaction_space();
   }
 }
 class AdjustPointersClosure: public SpaceClosure {
  public:
   void do_space(Space* sp) {
     sp->adjust_pointers();
   }
 };
 void Generation::adjust_pointers() {
   // Note that this is done over all spaces, not just the compactible
   // ones.
   AdjustPointersClosure blk;
   space_iterate(&blk, true);
 }
 void Generation::compact() {
   CompactibleSpace* sp = first_compaction_space();
   while (sp != NULL) {
     sp->compact();
     sp = sp->next_compaction_space();
   }
 }
 CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
                                int level,
                                GenRemSet* remset) :
   Generation(rs, initial_byte_size, level), _rs(remset),
   _shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
   _used_at_prologue()
 {
   HeapWord* start = (HeapWord*)rs.base();
   size_t reserved_byte_size = rs.size();
   assert((uintptr_t(start) & 3) == 0, "bad alignment");
   assert((reserved_byte_size & 3) == 0, "bad alignment");
   MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
   _bts = new BlockOffsetSharedArray(reserved_mr,
                                     heap_word_size(initial_byte_size));
   MemRegion committed_mr(start, heap_word_size(initial_byte_size));
   _rs->resize_covered_region(committed_mr);
   if (_bts == NULL)
     vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
   // Verify that the start and end of this generation is the start of a card.
   // If this wasn't true, a single card could span more than on generation,
   // which would cause problems when we commit/uncommit memory, and when we
   // clear and dirty cards.
   guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
   if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
     // Don't check at the very end of the heap as we'll assert that we're probing off
     // the end if we try.
     guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
   }
   _min_heap_delta_bytes = MinHeapDeltaBytes;
   _capacity_at_prologue = initial_byte_size;
   _used_at_prologue = 0;
 }
 bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
   assert_locked_or_safepoint(Heap_lock);
   if (bytes == 0) {
     return true;  // That's what grow_by(0) would return
   }
   size_t aligned_bytes  = ReservedSpace::page_align_size_up(bytes);
   if (aligned_bytes == 0){
     // The alignment caused the number of bytes to wrap.  An expand_by(0) will
     // return true with the implication that an expansion was done when it
     // was not.  A call to expand implies a best effort to expand by "bytes"
     // but not a guarantee.  Align down to give a best effort.  This is likely
     // the most that the generation can expand since it has some capacity to
     // start with.
     aligned_bytes = ReservedSpace::page_align_size_down(bytes);
   }
   size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
   bool success = false;
   if (aligned_expand_bytes > aligned_bytes) {
     success = grow_by(aligned_expand_bytes);
   }
   if (!success) {
     success = grow_by(aligned_bytes);
   }
   if (!success) {
     success = grow_to_reserved();
   }
   if (PrintGC && Verbose) {
     if (success && GC_locker::is_active_and_needs_gc()) {
       gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
     }
   }
   return success;
 }
 // No young generation references, clear this generation's cards.
 void CardGeneration::clear_remembered_set() {
   _rs->clear(reserved());
 }
 // Objects in this generation may have moved, invalidate this
 // generation's cards.
 void CardGeneration::invalidate_remembered_set() {
   _rs->invalidate(used_region());
 }
 void CardGeneration::compute_new_size() {
   assert(_shrink_factor <= 100, "invalid shrink factor");
   size_t current_shrink_factor = _shrink_factor;
   _shrink_factor = 0;
   // We don't have floating point command-line arguments
   // Note:  argument processing ensures that MinHeapFreeRatio < 100.
   const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
   // Compute some numbers about the state of the heap.
   const size_t used_after_gc = used();
   const size_t capacity_after_gc = capacity();
   const double min_tmp = used_after_gc / maximum_used_percentage;
   size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
   // Don't shrink less than the initial generation size
   minimum_desired_capacity = MAX2(minimum_desired_capacity,
                                   spec()->init_size());
   assert(used_after_gc <= minimum_desired_capacity, "sanity check");
   if (PrintGC && Verbose) {
     const size_t free_after_gc = free();
     const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
     gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
     gclog_or_tty->print_cr("  "
                   "  minimum_free_percentage: %6.2f"
                   "  maximum_used_percentage: %6.2f",
                   minimum_free_percentage,
                   maximum_used_percentage);
     gclog_or_tty->print_cr("  "
                   "   free_after_gc   : %6.1fK"
                   "   used_after_gc   : %6.1fK"
                   "   capacity_after_gc   : %6.1fK",
                   free_after_gc / (double) K,
                   used_after_gc / (double) K,
                   capacity_after_gc / (double) K);
     gclog_or_tty->print_cr("  "
                   "   free_percentage: %6.2f",
                   free_percentage);
   }
   if (capacity_after_gc < minimum_desired_capacity) {
     // If we have less free space than we want then expand
     size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
     // Don't expand unless it's significant
     if (expand_bytes >= _min_heap_delta_bytes) {
       expand(expand_bytes, 0); // safe if expansion fails
     }
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("    expanding:"
                     "  minimum_desired_capacity: %6.1fK"
                     "  expand_bytes: %6.1fK"
                     "  _min_heap_delta_bytes: %6.1fK",
                     minimum_desired_capacity / (double) K,
                     expand_bytes / (double) K,
                     _min_heap_delta_bytes / (double) K);
     }
     return;
   }
   // No expansion, now see if we want to shrink
   size_t shrink_bytes = 0;
   // We would never want to shrink more than this
   size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
   if (MaxHeapFreeRatio < 100) {
     const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
     const double max_tmp = used_after_gc / minimum_used_percentage;
     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
     maximum_desired_capacity = MAX2(maximum_desired_capacity,
                                     spec()->init_size());
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("  "
                              "  maximum_free_percentage: %6.2f"
                              "  minimum_used_percentage: %6.2f",
                              maximum_free_percentage,
                              minimum_used_percentage);
       gclog_or_tty->print_cr("  "
                              "  _capacity_at_prologue: %6.1fK"
                              "  minimum_desired_capacity: %6.1fK"
                              "  maximum_desired_capacity: %6.1fK",
                              _capacity_at_prologue / (double) K,
                              minimum_desired_capacity / (double) K,
                              maximum_desired_capacity / (double) K);
     }
     assert(minimum_desired_capacity <= maximum_desired_capacity,
            "sanity check");
     if (capacity_after_gc > maximum_desired_capacity) {
       // Capacity too large, compute shrinking size
       shrink_bytes = capacity_after_gc - maximum_desired_capacity;
       // We don't want shrink all the way back to initSize if people call
       // System.gc(), because some programs do that between "phases" and then
       // we'd just have to grow the heap up again for the next phase.  So we
       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
       // on the third call, and 100% by the fourth call.  But if we recompute
       // size without shrinking, it goes back to 0%.
       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
       assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
       if (current_shrink_factor == 0) {
         _shrink_factor = 10;
       } else {
         _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
       }
       if (PrintGC && Verbose) {
         gclog_or_tty->print_cr("  "
                       "  shrinking:"
                       "  initSize: %.1fK"
                       "  maximum_desired_capacity: %.1fK",
                       spec()->init_size() / (double) K,
                       maximum_desired_capacity / (double) K);
         gclog_or_tty->print_cr("  "
                       "  shrink_bytes: %.1fK"
                       "  current_shrink_factor: %d"
                       "  new shrink factor: %d"
                       "  _min_heap_delta_bytes: %.1fK",
                       shrink_bytes / (double) K,
                       current_shrink_factor,
                       _shrink_factor,
                       _min_heap_delta_bytes / (double) K);
       }
     }
   }
   if (capacity_after_gc > _capacity_at_prologue) {
     // We might have expanded for promotions, in which case we might want to
     // take back that expansion if there's room after GC.  That keeps us from
     // stretching the heap with promotions when there's plenty of room.
     size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
     expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
     // We have two shrinking computations, take the largest
     shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
     assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("  "
                              "  aggressive shrinking:"
                              "  _capacity_at_prologue: %.1fK"
                              "  capacity_after_gc: %.1fK"
                              "  expansion_for_promotion: %.1fK"
                              "  shrink_bytes: %.1fK",
                              capacity_after_gc / (double) K,
                              _capacity_at_prologue / (double) K,
                              expansion_for_promotion / (double) K,
                              shrink_bytes / (double) K);
     }
   }
   // Don't shrink unless it's significant
   if (shrink_bytes >= _min_heap_delta_bytes) {
     shrink(shrink_bytes);
   }
 }
 // Currently nothing to do.
 void CardGeneration::prepare_for_verify() {}
 void OneContigSpaceCardGeneration::collect(bool   full,
                                            bool   clear_all_soft_refs,
                                            size_t size,
                                            bool   is_tlab) {
   SpecializationStats::clear();
   // Temporarily expand the span of our ref processor, so
   // refs discovery is over the entire heap, not just this generation
   ReferenceProcessorSpanMutator
     x(ref_processor(), GenCollectedHeap::heap()->reserved_region());
   GenMarkSweep::invoke_at_safepoint(_level, ref_processor(), clear_all_soft_refs);
   SpecializationStats::print();
 }
 HeapWord*
 OneContigSpaceCardGeneration::expand_and_allocate(size_t word_size,
                                                   bool is_tlab,
                                                   bool parallel) {
   assert(!is_tlab, "OneContigSpaceCardGeneration does not support TLAB allocation");
   if (parallel) {
     MutexLocker x(ParGCRareEvent_lock);
     HeapWord* result = NULL;
     size_t byte_size = word_size * HeapWordSize;
     while (true) {
       expand(byte_size, _min_heap_delta_bytes);
       if (GCExpandToAllocateDelayMillis > 0) {
         os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false);
       }
       result = _the_space->par_allocate(word_size);
       if ( result != NULL) {
         return result;
       } else {
         // If there's not enough expansion space available, give up.
         if (_virtual_space.uncommitted_size() < byte_size) {
           return NULL;
         }
         // else try again
       }
     }
   } else {
     expand(word_size*HeapWordSize, _min_heap_delta_bytes);
     return _the_space->allocate(word_size);
   }
 }
 bool OneContigSpaceCardGeneration::expand(size_t bytes, size_t expand_bytes) {
   GCMutexLocker x(ExpandHeap_lock);
   return CardGeneration::expand(bytes, expand_bytes);
 }
 void OneContigSpaceCardGeneration::shrink(size_t bytes) {
   assert_locked_or_safepoint(ExpandHeap_lock);
   size_t size = ReservedSpace::page_align_size_down(bytes);
   if (size > 0) {
     shrink_by(size);
   }
 }
 size_t OneContigSpaceCardGeneration::capacity() const {
   return _the_space->capacity();
 }
 size_t OneContigSpaceCardGeneration::used() const {
   return _the_space->used();
 }
 size_t OneContigSpaceCardGeneration::free() const {
   return _the_space->free();
 }
 MemRegion OneContigSpaceCardGeneration::used_region() const {
   return the_space()->used_region();
 }
 size_t OneContigSpaceCardGeneration::unsafe_max_alloc_nogc() const {
   return _the_space->free();
 }
 size_t OneContigSpaceCardGeneration::contiguous_available() const {
   return _the_space->free() + _virtual_space.uncommitted_size();
 }
 bool OneContigSpaceCardGeneration::grow_by(size_t bytes) {
   assert_locked_or_safepoint(ExpandHeap_lock);
   bool result = _virtual_space.expand_by(bytes);
   if (result) {
     size_t new_word_size =
        heap_word_size(_virtual_space.committed_size());
     MemRegion mr(_the_space->bottom(), new_word_size);
     // Expand card table
     Universe::heap()->barrier_set()->resize_covered_region(mr);
     // Expand shared block offset array
     _bts->resize(new_word_size);
     // Fix for bug #4668531
     if (ZapUnusedHeapArea) {
       MemRegion mangle_region(_the_space->end(),
       (HeapWord*)_virtual_space.high());
       SpaceMangler::mangle_region(mangle_region);
     }
     // Expand space -- also expands space's BOT
     // (which uses (part of) shared array above)
     _the_space->set_end((HeapWord*)_virtual_space.high());
     // update the space and generation capacity counters
     update_counters();
     if (Verbose && PrintGC) {
       size_t new_mem_size = _virtual_space.committed_size();
       size_t old_mem_size = new_mem_size - bytes;
       gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by "
                       SIZE_FORMAT "K to " SIZE_FORMAT "K",
                       name(), old_mem_size/K, bytes/K, new_mem_size/K);
     }
   }
   return result;
 }
 bool OneContigSpaceCardGeneration::grow_to_reserved() {
   assert_locked_or_safepoint(ExpandHeap_lock);
   bool success = true;
   const size_t remaining_bytes = _virtual_space.uncommitted_size();
   if (remaining_bytes > 0) {
     success = grow_by(remaining_bytes);
     DEBUG_ONLY(if (!success) warning("grow to reserved failed");)
   }
   return success;
 }
 void OneContigSpaceCardGeneration::shrink_by(size_t bytes) {
   assert_locked_or_safepoint(ExpandHeap_lock);
   // Shrink committed space
   _virtual_space.shrink_by(bytes);
   // Shrink space; this also shrinks the space's BOT
   _the_space->set_end((HeapWord*) _virtual_space.high());
   size_t new_word_size = heap_word_size(_the_space->capacity());
   // Shrink the shared block offset array
   _bts->resize(new_word_size);
   MemRegion mr(_the_space->bottom(), new_word_size);
   // Shrink the card table
   Universe::heap()->barrier_set()->resize_covered_region(mr);
   if (Verbose && PrintGC) {
     size_t new_mem_size = _virtual_space.committed_size();
     size_t old_mem_size = new_mem_size + bytes;
     gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K",
                   name(), old_mem_size/K, new_mem_size/K);
   }
 }
 // Currently nothing to do.
 void OneContigSpaceCardGeneration::prepare_for_verify() {}
 // Override for a card-table generation with one contiguous
 // space. NOTE: For reasons that are lost in the fog of history,
 // this code is used when you iterate over perm gen objects,
 // even when one uses CDS, where the perm gen has a couple of
 // other spaces; this is because CompactingPermGenGen derives
 // from OneContigSpaceCardGeneration. This should be cleaned up,
 // see CR 6897789..
 void OneContigSpaceCardGeneration::object_iterate(ObjectClosure* blk) {
   _the_space->object_iterate(blk);
 }
 void OneContigSpaceCardGeneration::space_iterate(SpaceClosure* blk,
                                                  bool usedOnly) {
   blk->do_space(_the_space);
 }
 void OneContigSpaceCardGeneration::object_iterate_since_last_GC(ObjectClosure* blk) {
   // Deal with delayed initialization of _the_space,
   // and lack of initialization of _last_gc.
   if (_last_gc.space() == NULL) {
     assert(the_space() != NULL, "shouldn't be NULL");
     _last_gc = the_space()->bottom_mark();
   }
   the_space()->object_iterate_from(_last_gc, blk);
 }
 void OneContigSpaceCardGeneration::younger_refs_iterate(OopsInGenClosure* blk) {
   blk->set_generation(this);
   younger_refs_in_space_iterate(_the_space, blk);
   blk->reset_generation();
 }
 void OneContigSpaceCardGeneration::save_marks() {
   _the_space->set_saved_mark();
 }
 void OneContigSpaceCardGeneration::reset_saved_marks() {
   _the_space->reset_saved_mark();
 }
 bool OneContigSpaceCardGeneration::no_allocs_since_save_marks() {
   return _the_space->saved_mark_at_top();
 }
 #define OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix)      \
                                                                                 \
 void OneContigSpaceCardGeneration::                                             \
 oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) {                  \
   blk->set_generation(this);                                                    \
   _the_space->oop_since_save_marks_iterate##nv_suffix(blk);                     \
   blk->reset_generation();                                                      \
   save_marks();                                                                 \
 }
 ALL_SINCE_SAVE_MARKS_CLOSURES(OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN)
 #undef OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN
 void OneContigSpaceCardGeneration::gc_epilogue(bool full) {
   _last_gc = WaterMark(the_space(), the_space()->top());
   // update the generation and space performance counters
   update_counters();
   if (ZapUnusedHeapArea) {
     the_space()->check_mangled_unused_area_complete();
   }
 }
 void OneContigSpaceCardGeneration::record_spaces_top() {
   assert(ZapUnusedHeapArea, "Not mangling unused space");
   the_space()->set_top_for_allocations();
 }
 void OneContigSpaceCardGeneration::verify() {
   the_space()->verify();
 }
 void OneContigSpaceCardGeneration::print_on(outputStream* st)  const {
   Generation::print_on(st);
   st->print("   the");
   the_space()->print_on(st);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/generation.cpp@2958af1d8c5a (annotated)

src/share/vm/memory/generation.cpp