aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 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@0: #include "precompiled.hpp"
aoqi@0: #include "gc_implementation/shared/gcTimer.hpp"
aoqi@0: #include "gc_implementation/shared/gcTrace.hpp"
aoqi@0: #include "gc_implementation/shared/spaceDecorator.hpp"
aoqi@0: #include "gc_interface/collectedHeap.inline.hpp"
aoqi@0: #include "memory/allocation.inline.hpp"
aoqi@0: #include "memory/blockOffsetTable.inline.hpp"
aoqi@0: #include "memory/cardTableRS.hpp"
aoqi@0: #include "memory/gcLocker.inline.hpp"
aoqi@0: #include "memory/genCollectedHeap.hpp"
aoqi@0: #include "memory/genMarkSweep.hpp"
aoqi@0: #include "memory/genOopClosures.hpp"
aoqi@0: #include "memory/genOopClosures.inline.hpp"
aoqi@0: #include "memory/generation.hpp"
aoqi@0: #include "memory/generation.inline.hpp"
aoqi@0: #include "memory/space.inline.hpp"
aoqi@0: #include "oops/oop.inline.hpp"
aoqi@0: #include "runtime/java.hpp"
aoqi@0: #include "utilities/copy.hpp"
aoqi@0: #include "utilities/events.hpp"
aoqi@0: 
aoqi@0: PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
aoqi@0: 
aoqi@0: Generation::Generation(ReservedSpace rs, size_t initial_size, int level) :
aoqi@0:   _level(level),
aoqi@0:   _ref_processor(NULL) {
aoqi@0:   if (!_virtual_space.initialize(rs, initial_size)) {
aoqi@0:     vm_exit_during_initialization("Could not reserve enough space for "
aoqi@0:                     "object heap");
aoqi@0:   }
aoqi@0:   // Mangle all of the the initial generation.
aoqi@0:   if (ZapUnusedHeapArea) {
aoqi@0:     MemRegion mangle_region((HeapWord*)_virtual_space.low(),
aoqi@0:       (HeapWord*)_virtual_space.high());
aoqi@0:     SpaceMangler::mangle_region(mangle_region);
aoqi@0:   }
aoqi@0:   _reserved = MemRegion((HeapWord*)_virtual_space.low_boundary(),
aoqi@0:           (HeapWord*)_virtual_space.high_boundary());
aoqi@0: }
aoqi@0: 
aoqi@0: GenerationSpec* Generation::spec() {
aoqi@0:   GenCollectedHeap* gch = GenCollectedHeap::heap();
aoqi@0:   assert(0 <= level() && level() < gch->_n_gens, "Bad gen level");
aoqi@0:   return gch->_gen_specs[level()];
aoqi@0: }
aoqi@0: 
aoqi@0: size_t Generation::max_capacity() const {
aoqi@0:   return reserved().byte_size();
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::print_heap_change(size_t prev_used) const {
aoqi@0:   if (PrintGCDetails && Verbose) {
aoqi@0:     gclog_or_tty->print(" "  SIZE_FORMAT
aoqi@0:                         "->" SIZE_FORMAT
aoqi@0:                         "("  SIZE_FORMAT ")",
aoqi@0:                         prev_used, used(), capacity());
aoqi@0:   } else {
aoqi@0:     gclog_or_tty->print(" "  SIZE_FORMAT "K"
aoqi@0:                         "->" SIZE_FORMAT "K"
aoqi@0:                         "("  SIZE_FORMAT "K)",
aoqi@0:                         prev_used / K, used() / K, capacity() / K);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // By default we get a single threaded default reference processor;
aoqi@0: // generations needing multi-threaded refs processing or discovery override this method.
aoqi@0: void Generation::ref_processor_init() {
aoqi@0:   assert(_ref_processor == NULL, "a reference processor already exists");
aoqi@0:   assert(!_reserved.is_empty(), "empty generation?");
aoqi@0:   _ref_processor = new ReferenceProcessor(_reserved);    // a vanilla reference processor
aoqi@0:   if (_ref_processor == NULL) {
aoqi@0:     vm_exit_during_initialization("Could not allocate ReferenceProcessor object");
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::print() const { print_on(tty); }
aoqi@0: 
aoqi@0: void Generation::print_on(outputStream* st)  const {
aoqi@0:   st->print(" %-20s", name());
aoqi@0:   st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
aoqi@0:              capacity()/K, used()/K);
aoqi@0:   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
aoqi@0:               _virtual_space.low_boundary(),
aoqi@0:               _virtual_space.high(),
aoqi@0:               _virtual_space.high_boundary());
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::print_summary_info() { print_summary_info_on(tty); }
aoqi@0: 
aoqi@0: void Generation::print_summary_info_on(outputStream* st) {
aoqi@0:   StatRecord* sr = stat_record();
aoqi@0:   double time = sr->accumulated_time.seconds();
aoqi@0:   st->print_cr("[Accumulated GC generation %d time %3.7f secs, "
aoqi@0:                "%d GC's, avg GC time %3.7f]",
aoqi@0:                level(), time, sr->invocations,
aoqi@0:                sr->invocations > 0 ? time / sr->invocations : 0.0);
aoqi@0: }
aoqi@0: 
aoqi@0: // Utility iterator classes
aoqi@0: 
aoqi@0: class GenerationIsInReservedClosure : public SpaceClosure {
aoqi@0:  public:
aoqi@0:   const void* _p;
aoqi@0:   Space* sp;
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     if (sp == NULL) {
aoqi@0:       if (s->is_in_reserved(_p)) sp = s;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   GenerationIsInReservedClosure(const void* p) : _p(p), sp(NULL) {}
aoqi@0: };
aoqi@0: 
aoqi@0: class GenerationIsInClosure : public SpaceClosure {
aoqi@0:  public:
aoqi@0:   const void* _p;
aoqi@0:   Space* sp;
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     if (sp == NULL) {
aoqi@0:       if (s->is_in(_p)) sp = s;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   GenerationIsInClosure(const void* p) : _p(p), sp(NULL) {}
aoqi@0: };
aoqi@0: 
aoqi@0: bool Generation::is_in(const void* p) const {
aoqi@0:   GenerationIsInClosure blk(p);
aoqi@0:   ((Generation*)this)->space_iterate(&blk);
aoqi@0:   return blk.sp != NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: DefNewGeneration* Generation::as_DefNewGeneration() {
aoqi@0:   assert((kind() == Generation::DefNew) ||
aoqi@0:          (kind() == Generation::ParNew) ||
aoqi@0:          (kind() == Generation::ASParNew),
aoqi@0:     "Wrong youngest generation type");
aoqi@0:   return (DefNewGeneration*) this;
aoqi@0: }
aoqi@0: 
aoqi@0: Generation* Generation::next_gen() const {
aoqi@0:   GenCollectedHeap* gch = GenCollectedHeap::heap();
aoqi@0:   int next = level() + 1;
aoqi@0:   if (next < gch->_n_gens) {
aoqi@0:     return gch->_gens[next];
aoqi@0:   } else {
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: size_t Generation::max_contiguous_available() const {
aoqi@0:   // The largest number of contiguous free words in this or any higher generation.
aoqi@0:   size_t max = 0;
aoqi@0:   for (const Generation* gen = this; gen != NULL; gen = gen->next_gen()) {
aoqi@0:     size_t avail = gen->contiguous_available();
aoqi@0:     if (avail > max) {
aoqi@0:       max = avail;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return max;
aoqi@0: }
aoqi@0: 
aoqi@0: bool Generation::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
aoqi@0:   size_t available = max_contiguous_available();
aoqi@0:   bool   res = (available >= max_promotion_in_bytes);
aoqi@0:   if (PrintGC && Verbose) {
aoqi@0:     gclog_or_tty->print_cr(
aoqi@0:       "Generation: promo attempt is%s safe: available("SIZE_FORMAT") %s max_promo("SIZE_FORMAT")",
aoqi@0:       res? "":" not", available, res? ">=":"<",
aoqi@0:       max_promotion_in_bytes);
aoqi@0:   }
aoqi@0:   return res;
aoqi@0: }
aoqi@0: 
aoqi@0: // Ignores "ref" and calls allocate().
aoqi@0: oop Generation::promote(oop obj, size_t obj_size) {
aoqi@0:   assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0:   if (Universe::heap()->promotion_should_fail()) {
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0: #endif  // #ifndef PRODUCT
aoqi@0: 
aoqi@0:   HeapWord* result = allocate(obj_size, false);
aoqi@0:   if (result != NULL) {
aoqi@0:     Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
aoqi@0:     return oop(result);
aoqi@0:   } else {
aoqi@0:     GenCollectedHeap* gch = GenCollectedHeap::heap();
aoqi@0:     return gch->handle_failed_promotion(this, obj, obj_size);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: oop Generation::par_promote(int thread_num,
aoqi@0:                             oop obj, markOop m, size_t word_sz) {
aoqi@0:   // Could do a bad general impl here that gets a lock.  But no.
aoqi@0:   ShouldNotCallThis();
aoqi@0:   return NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::par_promote_alloc_undo(int thread_num,
aoqi@0:                                         HeapWord* obj, size_t word_sz) {
aoqi@0:   // Could do a bad general impl here that gets a lock.  But no.
aoqi@0:   guarantee(false, "No good general implementation.");
aoqi@0: }
aoqi@0: 
aoqi@0: Space* Generation::space_containing(const void* p) const {
aoqi@0:   GenerationIsInReservedClosure blk(p);
aoqi@0:   // Cast away const
aoqi@0:   ((Generation*)this)->space_iterate(&blk);
aoqi@0:   return blk.sp;
aoqi@0: }
aoqi@0: 
aoqi@0: // Some of these are mediocre general implementations.  Should be
aoqi@0: // overridden to get better performance.
aoqi@0: 
aoqi@0: class GenerationBlockStartClosure : public SpaceClosure {
aoqi@0:  public:
aoqi@0:   const void* _p;
aoqi@0:   HeapWord* _start;
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     if (_start == NULL && s->is_in_reserved(_p)) {
aoqi@0:       _start = s->block_start(_p);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   GenerationBlockStartClosure(const void* p) { _p = p; _start = NULL; }
aoqi@0: };
aoqi@0: 
aoqi@0: HeapWord* Generation::block_start(const void* p) const {
aoqi@0:   GenerationBlockStartClosure blk(p);
aoqi@0:   // Cast away const
aoqi@0:   ((Generation*)this)->space_iterate(&blk);
aoqi@0:   return blk._start;
aoqi@0: }
aoqi@0: 
aoqi@0: class GenerationBlockSizeClosure : public SpaceClosure {
aoqi@0:  public:
aoqi@0:   const HeapWord* _p;
aoqi@0:   size_t size;
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     if (size == 0 && s->is_in_reserved(_p)) {
aoqi@0:       size = s->block_size(_p);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   GenerationBlockSizeClosure(const HeapWord* p) { _p = p; size = 0; }
aoqi@0: };
aoqi@0: 
aoqi@0: size_t Generation::block_size(const HeapWord* p) const {
aoqi@0:   GenerationBlockSizeClosure blk(p);
aoqi@0:   // Cast away const
aoqi@0:   ((Generation*)this)->space_iterate(&blk);
aoqi@0:   assert(blk.size > 0, "seems reasonable");
aoqi@0:   return blk.size;
aoqi@0: }
aoqi@0: 
aoqi@0: class GenerationBlockIsObjClosure : public SpaceClosure {
aoqi@0:  public:
aoqi@0:   const HeapWord* _p;
aoqi@0:   bool is_obj;
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     if (!is_obj && s->is_in_reserved(_p)) {
aoqi@0:       is_obj |= s->block_is_obj(_p);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   GenerationBlockIsObjClosure(const HeapWord* p) { _p = p; is_obj = false; }
aoqi@0: };
aoqi@0: 
aoqi@0: bool Generation::block_is_obj(const HeapWord* p) const {
aoqi@0:   GenerationBlockIsObjClosure blk(p);
aoqi@0:   // Cast away const
aoqi@0:   ((Generation*)this)->space_iterate(&blk);
aoqi@0:   return blk.is_obj;
aoqi@0: }
aoqi@0: 
aoqi@0: class GenerationOopIterateClosure : public SpaceClosure {
aoqi@0:  public:
mgerdin@6978:   ExtendedOopClosure* _cl;
aoqi@0:   virtual void do_space(Space* s) {
mgerdin@6978:     s->oop_iterate(_cl);
aoqi@0:   }
mgerdin@6978:   GenerationOopIterateClosure(ExtendedOopClosure* cl) :
mgerdin@6978:     _cl(cl) {}
aoqi@0: };
aoqi@0: 
aoqi@0: void Generation::oop_iterate(ExtendedOopClosure* cl) {
mgerdin@6978:   GenerationOopIterateClosure blk(cl);
aoqi@0:   space_iterate(&blk);
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::younger_refs_in_space_iterate(Space* sp,
aoqi@0:                                                OopsInGenClosure* cl) {
aoqi@0:   GenRemSet* rs = SharedHeap::heap()->rem_set();
aoqi@0:   rs->younger_refs_in_space_iterate(sp, cl);
aoqi@0: }
aoqi@0: 
aoqi@0: class GenerationObjIterateClosure : public SpaceClosure {
aoqi@0:  private:
aoqi@0:   ObjectClosure* _cl;
aoqi@0:  public:
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     s->object_iterate(_cl);
aoqi@0:   }
aoqi@0:   GenerationObjIterateClosure(ObjectClosure* cl) : _cl(cl) {}
aoqi@0: };
aoqi@0: 
aoqi@0: void Generation::object_iterate(ObjectClosure* cl) {
aoqi@0:   GenerationObjIterateClosure blk(cl);
aoqi@0:   space_iterate(&blk);
aoqi@0: }
aoqi@0: 
aoqi@0: class GenerationSafeObjIterateClosure : public SpaceClosure {
aoqi@0:  private:
aoqi@0:   ObjectClosure* _cl;
aoqi@0:  public:
aoqi@0:   virtual void do_space(Space* s) {
aoqi@0:     s->safe_object_iterate(_cl);
aoqi@0:   }
aoqi@0:   GenerationSafeObjIterateClosure(ObjectClosure* cl) : _cl(cl) {}
aoqi@0: };
aoqi@0: 
aoqi@0: void Generation::safe_object_iterate(ObjectClosure* cl) {
aoqi@0:   GenerationSafeObjIterateClosure blk(cl);
aoqi@0:   space_iterate(&blk);
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::prepare_for_compaction(CompactPoint* cp) {
aoqi@0:   // Generic implementation, can be specialized
aoqi@0:   CompactibleSpace* space = first_compaction_space();
aoqi@0:   while (space != NULL) {
aoqi@0:     space->prepare_for_compaction(cp);
aoqi@0:     space = space->next_compaction_space();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: class AdjustPointersClosure: public SpaceClosure {
aoqi@0:  public:
aoqi@0:   void do_space(Space* sp) {
aoqi@0:     sp->adjust_pointers();
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: void Generation::adjust_pointers() {
aoqi@0:   // Note that this is done over all spaces, not just the compactible
aoqi@0:   // ones.
aoqi@0:   AdjustPointersClosure blk;
aoqi@0:   space_iterate(&blk, true);
aoqi@0: }
aoqi@0: 
aoqi@0: void Generation::compact() {
aoqi@0:   CompactibleSpace* sp = first_compaction_space();
aoqi@0:   while (sp != NULL) {
aoqi@0:     sp->compact();
aoqi@0:     sp = sp->next_compaction_space();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
aoqi@0:                                int level,
aoqi@0:                                GenRemSet* remset) :
aoqi@0:   Generation(rs, initial_byte_size, level), _rs(remset),
aoqi@0:   _shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
aoqi@0:   _used_at_prologue()
aoqi@0: {
aoqi@0:   HeapWord* start = (HeapWord*)rs.base();
aoqi@0:   size_t reserved_byte_size = rs.size();
aoqi@0:   assert((uintptr_t(start) & 3) == 0, "bad alignment");
aoqi@0:   assert((reserved_byte_size & 3) == 0, "bad alignment");
aoqi@0:   MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
aoqi@0:   _bts = new BlockOffsetSharedArray(reserved_mr,
aoqi@0:                                     heap_word_size(initial_byte_size));
aoqi@0:   MemRegion committed_mr(start, heap_word_size(initial_byte_size));
aoqi@0:   _rs->resize_covered_region(committed_mr);
aoqi@0:   if (_bts == NULL)
aoqi@0:     vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
aoqi@0: 
aoqi@0:   // Verify that the start and end of this generation is the start of a card.
aoqi@0:   // If this wasn't true, a single card could span more than on generation,
aoqi@0:   // which would cause problems when we commit/uncommit memory, and when we
aoqi@0:   // clear and dirty cards.
aoqi@0:   guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
aoqi@0:   if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
aoqi@0:     // Don't check at the very end of the heap as we'll assert that we're probing off
aoqi@0:     // the end if we try.
aoqi@0:     guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
aoqi@0:   }
aoqi@0:   _min_heap_delta_bytes = MinHeapDeltaBytes;
aoqi@0:   _capacity_at_prologue = initial_byte_size;
aoqi@0:   _used_at_prologue = 0;
aoqi@0: }
aoqi@0: 
aoqi@0: bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
aoqi@0:   assert_locked_or_safepoint(Heap_lock);
aoqi@0:   if (bytes == 0) {
aoqi@0:     return true;  // That's what grow_by(0) would return
aoqi@0:   }
aoqi@0:   size_t aligned_bytes  = ReservedSpace::page_align_size_up(bytes);
aoqi@0:   if (aligned_bytes == 0){
aoqi@0:     // The alignment caused the number of bytes to wrap.  An expand_by(0) will
aoqi@0:     // return true with the implication that an expansion was done when it
aoqi@0:     // was not.  A call to expand implies a best effort to expand by "bytes"
aoqi@0:     // but not a guarantee.  Align down to give a best effort.  This is likely
aoqi@0:     // the most that the generation can expand since it has some capacity to
aoqi@0:     // start with.
aoqi@0:     aligned_bytes = ReservedSpace::page_align_size_down(bytes);
aoqi@0:   }
aoqi@0:   size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
aoqi@0:   bool success = false;
aoqi@0:   if (aligned_expand_bytes > aligned_bytes) {
aoqi@0:     success = grow_by(aligned_expand_bytes);
aoqi@0:   }
aoqi@0:   if (!success) {
aoqi@0:     success = grow_by(aligned_bytes);
aoqi@0:   }
aoqi@0:   if (!success) {
aoqi@0:     success = grow_to_reserved();
aoqi@0:   }
aoqi@0:   if (PrintGC && Verbose) {
aoqi@0:     if (success && GC_locker::is_active_and_needs_gc()) {
aoqi@0:       gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   return success;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: // No young generation references, clear this generation's cards.
aoqi@0: void CardGeneration::clear_remembered_set() {
aoqi@0:   _rs->clear(reserved());
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: // Objects in this generation may have moved, invalidate this
aoqi@0: // generation's cards.
aoqi@0: void CardGeneration::invalidate_remembered_set() {
aoqi@0:   _rs->invalidate(used_region());
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void CardGeneration::compute_new_size() {
aoqi@0:   assert(_shrink_factor <= 100, "invalid shrink factor");
aoqi@0:   size_t current_shrink_factor = _shrink_factor;
aoqi@0:   _shrink_factor = 0;
aoqi@0: 
aoqi@0:   // We don't have floating point command-line arguments
aoqi@0:   // Note:  argument processing ensures that MinHeapFreeRatio < 100.
aoqi@0:   const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
aoqi@0:   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
aoqi@0: 
aoqi@0:   // Compute some numbers about the state of the heap.
aoqi@0:   const size_t used_after_gc = used();
aoqi@0:   const size_t capacity_after_gc = capacity();
aoqi@0: 
aoqi@0:   const double min_tmp = used_after_gc / maximum_used_percentage;
aoqi@0:   size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
aoqi@0:   // Don't shrink less than the initial generation size
aoqi@0:   minimum_desired_capacity = MAX2(minimum_desired_capacity,
aoqi@0:                                   spec()->init_size());
aoqi@0:   assert(used_after_gc <= minimum_desired_capacity, "sanity check");
aoqi@0: 
aoqi@0:   if (PrintGC && Verbose) {
aoqi@0:     const size_t free_after_gc = free();
aoqi@0:     const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
aoqi@0:     gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "  minimum_free_percentage: %6.2f"
aoqi@0:                   "  maximum_used_percentage: %6.2f",
aoqi@0:                   minimum_free_percentage,
aoqi@0:                   maximum_used_percentage);
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "   free_after_gc   : %6.1fK"
aoqi@0:                   "   used_after_gc   : %6.1fK"
aoqi@0:                   "   capacity_after_gc   : %6.1fK",
aoqi@0:                   free_after_gc / (double) K,
aoqi@0:                   used_after_gc / (double) K,
aoqi@0:                   capacity_after_gc / (double) K);
aoqi@0:     gclog_or_tty->print_cr("  "
aoqi@0:                   "   free_percentage: %6.2f",
aoqi@0:                   free_percentage);
aoqi@0:   }
aoqi@0: 
aoqi@0:   if (capacity_after_gc < minimum_desired_capacity) {
aoqi@0:     // If we have less free space than we want then expand
aoqi@0:     size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
aoqi@0:     // Don't expand unless it's significant
aoqi@0:     if (expand_bytes >= _min_heap_delta_bytes) {
aoqi@0:       expand(expand_bytes, 0); // safe if expansion fails
aoqi@0:     }
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("    expanding:"
aoqi@0:                     "  minimum_desired_capacity: %6.1fK"
aoqi@0:                     "  expand_bytes: %6.1fK"
aoqi@0:                     "  _min_heap_delta_bytes: %6.1fK",
aoqi@0:                     minimum_desired_capacity / (double) K,
aoqi@0:                     expand_bytes / (double) K,
aoqi@0:                     _min_heap_delta_bytes / (double) K);
aoqi@0:     }
aoqi@0:     return;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // No expansion, now see if we want to shrink
aoqi@0:   size_t shrink_bytes = 0;
aoqi@0:   // We would never want to shrink more than this
aoqi@0:   size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
aoqi@0: 
aoqi@0:   if (MaxHeapFreeRatio < 100) {
aoqi@0:     const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
aoqi@0:     const double minimum_used_percentage = 1.0 - maximum_free_percentage;
aoqi@0:     const double max_tmp = used_after_gc / minimum_used_percentage;
aoqi@0:     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
aoqi@0:     maximum_desired_capacity = MAX2(maximum_desired_capacity,
aoqi@0:                                     spec()->init_size());
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("  "
aoqi@0:                              "  maximum_free_percentage: %6.2f"
aoqi@0:                              "  minimum_used_percentage: %6.2f",
aoqi@0:                              maximum_free_percentage,
aoqi@0:                              minimum_used_percentage);
aoqi@0:       gclog_or_tty->print_cr("  "
aoqi@0:                              "  _capacity_at_prologue: %6.1fK"
aoqi@0:                              "  minimum_desired_capacity: %6.1fK"
aoqi@0:                              "  maximum_desired_capacity: %6.1fK",
aoqi@0:                              _capacity_at_prologue / (double) K,
aoqi@0:                              minimum_desired_capacity / (double) K,
aoqi@0:                              maximum_desired_capacity / (double) K);
aoqi@0:     }
aoqi@0:     assert(minimum_desired_capacity <= maximum_desired_capacity,
aoqi@0:            "sanity check");
aoqi@0: 
aoqi@0:     if (capacity_after_gc > maximum_desired_capacity) {
aoqi@0:       // Capacity too large, compute shrinking size
aoqi@0:       shrink_bytes = capacity_after_gc - maximum_desired_capacity;
aoqi@0:       // We don't want shrink all the way back to initSize if people call
aoqi@0:       // System.gc(), because some programs do that between "phases" and then
aoqi@0:       // we'd just have to grow the heap up again for the next phase.  So we
aoqi@0:       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
aoqi@0:       // on the third call, and 100% by the fourth call.  But if we recompute
aoqi@0:       // size without shrinking, it goes back to 0%.
aoqi@0:       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
aoqi@0:       assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
aoqi@0:       if (current_shrink_factor == 0) {
aoqi@0:         _shrink_factor = 10;
aoqi@0:       } else {
aoqi@0:         _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
aoqi@0:       }
aoqi@0:       if (PrintGC && Verbose) {
aoqi@0:         gclog_or_tty->print_cr("  "
aoqi@0:                       "  shrinking:"
aoqi@0:                       "  initSize: %.1fK"
aoqi@0:                       "  maximum_desired_capacity: %.1fK",
aoqi@0:                       spec()->init_size() / (double) K,
aoqi@0:                       maximum_desired_capacity / (double) K);
aoqi@0:         gclog_or_tty->print_cr("  "
aoqi@0:                       "  shrink_bytes: %.1fK"
aoqi@0:                       "  current_shrink_factor: %d"
aoqi@0:                       "  new shrink factor: %d"
aoqi@0:                       "  _min_heap_delta_bytes: %.1fK",
aoqi@0:                       shrink_bytes / (double) K,
aoqi@0:                       current_shrink_factor,
aoqi@0:                       _shrink_factor,
aoqi@0:                       _min_heap_delta_bytes / (double) K);
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   if (capacity_after_gc > _capacity_at_prologue) {
aoqi@0:     // We might have expanded for promotions, in which case we might want to
aoqi@0:     // take back that expansion if there's room after GC.  That keeps us from
aoqi@0:     // stretching the heap with promotions when there's plenty of room.
aoqi@0:     size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
aoqi@0:     expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
aoqi@0:     // We have two shrinking computations, take the largest
aoqi@0:     shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
aoqi@0:     assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("  "
aoqi@0:                              "  aggressive shrinking:"
aoqi@0:                              "  _capacity_at_prologue: %.1fK"
aoqi@0:                              "  capacity_after_gc: %.1fK"
aoqi@0:                              "  expansion_for_promotion: %.1fK"
aoqi@0:                              "  shrink_bytes: %.1fK",
aoqi@0:                              capacity_after_gc / (double) K,
aoqi@0:                              _capacity_at_prologue / (double) K,
aoqi@0:                              expansion_for_promotion / (double) K,
aoqi@0:                              shrink_bytes / (double) K);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // Don't shrink unless it's significant
aoqi@0:   if (shrink_bytes >= _min_heap_delta_bytes) {
aoqi@0:     shrink(shrink_bytes);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Currently nothing to do.
aoqi@0: void CardGeneration::prepare_for_verify() {}
aoqi@0: 
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::collect(bool   full,
aoqi@0:                                            bool   clear_all_soft_refs,
aoqi@0:                                            size_t size,
aoqi@0:                                            bool   is_tlab) {
aoqi@0:   GenCollectedHeap* gch = GenCollectedHeap::heap();
aoqi@0: 
aoqi@0:   SpecializationStats::clear();
aoqi@0:   // Temporarily expand the span of our ref processor, so
aoqi@0:   // refs discovery is over the entire heap, not just this generation
aoqi@0:   ReferenceProcessorSpanMutator
aoqi@0:     x(ref_processor(), gch->reserved_region());
aoqi@0: 
aoqi@0:   STWGCTimer* gc_timer = GenMarkSweep::gc_timer();
aoqi@0:   gc_timer->register_gc_start();
aoqi@0: 
aoqi@0:   SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer();
aoqi@0:   gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start());
aoqi@0: 
aoqi@0:   GenMarkSweep::invoke_at_safepoint(_level, ref_processor(), clear_all_soft_refs);
aoqi@0: 
aoqi@0:   gc_timer->register_gc_end();
aoqi@0: 
aoqi@0:   gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions());
aoqi@0: 
aoqi@0:   SpecializationStats::print();
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord*
aoqi@0: OneContigSpaceCardGeneration::expand_and_allocate(size_t word_size,
aoqi@0:                                                   bool is_tlab,
aoqi@0:                                                   bool parallel) {
aoqi@0:   assert(!is_tlab, "OneContigSpaceCardGeneration does not support TLAB allocation");
aoqi@0:   if (parallel) {
aoqi@0:     MutexLocker x(ParGCRareEvent_lock);
aoqi@0:     HeapWord* result = NULL;
aoqi@0:     size_t byte_size = word_size * HeapWordSize;
aoqi@0:     while (true) {
aoqi@0:       expand(byte_size, _min_heap_delta_bytes);
aoqi@0:       if (GCExpandToAllocateDelayMillis > 0) {
aoqi@0:         os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false);
aoqi@0:       }
aoqi@0:       result = _the_space->par_allocate(word_size);
aoqi@0:       if ( result != NULL) {
aoqi@0:         return result;
aoqi@0:       } else {
aoqi@0:         // If there's not enough expansion space available, give up.
aoqi@0:         if (_virtual_space.uncommitted_size() < byte_size) {
aoqi@0:           return NULL;
aoqi@0:         }
aoqi@0:         // else try again
aoqi@0:       }
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     expand(word_size*HeapWordSize, _min_heap_delta_bytes);
aoqi@0:     return _the_space->allocate(word_size);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: bool OneContigSpaceCardGeneration::expand(size_t bytes, size_t expand_bytes) {
aoqi@0:   GCMutexLocker x(ExpandHeap_lock);
aoqi@0:   return CardGeneration::expand(bytes, expand_bytes);
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::shrink(size_t bytes) {
aoqi@0:   assert_locked_or_safepoint(ExpandHeap_lock);
aoqi@0:   size_t size = ReservedSpace::page_align_size_down(bytes);
aoqi@0:   if (size > 0) {
aoqi@0:     shrink_by(size);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: size_t OneContigSpaceCardGeneration::capacity() const {
aoqi@0:   return _the_space->capacity();
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: size_t OneContigSpaceCardGeneration::used() const {
aoqi@0:   return _the_space->used();
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: size_t OneContigSpaceCardGeneration::free() const {
aoqi@0:   return _the_space->free();
aoqi@0: }
aoqi@0: 
aoqi@0: MemRegion OneContigSpaceCardGeneration::used_region() const {
aoqi@0:   return the_space()->used_region();
aoqi@0: }
aoqi@0: 
aoqi@0: size_t OneContigSpaceCardGeneration::unsafe_max_alloc_nogc() const {
aoqi@0:   return _the_space->free();
aoqi@0: }
aoqi@0: 
aoqi@0: size_t OneContigSpaceCardGeneration::contiguous_available() const {
aoqi@0:   return _the_space->free() + _virtual_space.uncommitted_size();
aoqi@0: }
aoqi@0: 
aoqi@0: bool OneContigSpaceCardGeneration::grow_by(size_t bytes) {
aoqi@0:   assert_locked_or_safepoint(ExpandHeap_lock);
aoqi@0:   bool result = _virtual_space.expand_by(bytes);
aoqi@0:   if (result) {
aoqi@0:     size_t new_word_size =
aoqi@0:        heap_word_size(_virtual_space.committed_size());
aoqi@0:     MemRegion mr(_the_space->bottom(), new_word_size);
aoqi@0:     // Expand card table
aoqi@0:     Universe::heap()->barrier_set()->resize_covered_region(mr);
aoqi@0:     // Expand shared block offset array
aoqi@0:     _bts->resize(new_word_size);
aoqi@0: 
aoqi@0:     // Fix for bug #4668531
aoqi@0:     if (ZapUnusedHeapArea) {
aoqi@0:       MemRegion mangle_region(_the_space->end(),
aoqi@0:       (HeapWord*)_virtual_space.high());
aoqi@0:       SpaceMangler::mangle_region(mangle_region);
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Expand space -- also expands space's BOT
aoqi@0:     // (which uses (part of) shared array above)
aoqi@0:     _the_space->set_end((HeapWord*)_virtual_space.high());
aoqi@0: 
aoqi@0:     // update the space and generation capacity counters
aoqi@0:     update_counters();
aoqi@0: 
aoqi@0:     if (Verbose && PrintGC) {
aoqi@0:       size_t new_mem_size = _virtual_space.committed_size();
aoqi@0:       size_t old_mem_size = new_mem_size - bytes;
aoqi@0:       gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by "
aoqi@0:                       SIZE_FORMAT "K to " SIZE_FORMAT "K",
aoqi@0:                       name(), old_mem_size/K, bytes/K, new_mem_size/K);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return result;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool OneContigSpaceCardGeneration::grow_to_reserved() {
aoqi@0:   assert_locked_or_safepoint(ExpandHeap_lock);
aoqi@0:   bool success = true;
aoqi@0:   const size_t remaining_bytes = _virtual_space.uncommitted_size();
aoqi@0:   if (remaining_bytes > 0) {
aoqi@0:     success = grow_by(remaining_bytes);
aoqi@0:     DEBUG_ONLY(if (!success) warning("grow to reserved failed");)
aoqi@0:   }
aoqi@0:   return success;
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::shrink_by(size_t bytes) {
aoqi@0:   assert_locked_or_safepoint(ExpandHeap_lock);
aoqi@0:   // Shrink committed space
aoqi@0:   _virtual_space.shrink_by(bytes);
aoqi@0:   // Shrink space; this also shrinks the space's BOT
aoqi@0:   _the_space->set_end((HeapWord*) _virtual_space.high());
aoqi@0:   size_t new_word_size = heap_word_size(_the_space->capacity());
aoqi@0:   // Shrink the shared block offset array
aoqi@0:   _bts->resize(new_word_size);
aoqi@0:   MemRegion mr(_the_space->bottom(), new_word_size);
aoqi@0:   // Shrink the card table
aoqi@0:   Universe::heap()->barrier_set()->resize_covered_region(mr);
aoqi@0: 
aoqi@0:   if (Verbose && PrintGC) {
aoqi@0:     size_t new_mem_size = _virtual_space.committed_size();
aoqi@0:     size_t old_mem_size = new_mem_size + bytes;
aoqi@0:     gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K",
aoqi@0:                   name(), old_mem_size/K, new_mem_size/K);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Currently nothing to do.
aoqi@0: void OneContigSpaceCardGeneration::prepare_for_verify() {}
aoqi@0: 
aoqi@0: 
aoqi@0: // Override for a card-table generation with one contiguous
aoqi@0: // space. NOTE: For reasons that are lost in the fog of history,
aoqi@0: // this code is used when you iterate over perm gen objects,
aoqi@0: // even when one uses CDS, where the perm gen has a couple of
aoqi@0: // other spaces; this is because CompactingPermGenGen derives
aoqi@0: // from OneContigSpaceCardGeneration. This should be cleaned up,
aoqi@0: // see CR 6897789..
aoqi@0: void OneContigSpaceCardGeneration::object_iterate(ObjectClosure* blk) {
aoqi@0:   _the_space->object_iterate(blk);
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::space_iterate(SpaceClosure* blk,
aoqi@0:                                                  bool usedOnly) {
aoqi@0:   blk->do_space(_the_space);
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::younger_refs_iterate(OopsInGenClosure* blk) {
aoqi@0:   blk->set_generation(this);
aoqi@0:   younger_refs_in_space_iterate(_the_space, blk);
aoqi@0:   blk->reset_generation();
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::save_marks() {
aoqi@0:   _the_space->set_saved_mark();
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::reset_saved_marks() {
aoqi@0:   _the_space->reset_saved_mark();
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool OneContigSpaceCardGeneration::no_allocs_since_save_marks() {
aoqi@0:   return _the_space->saved_mark_at_top();
aoqi@0: }
aoqi@0: 
aoqi@0: #define OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix)      \
aoqi@0:                                                                                 \
aoqi@0: void OneContigSpaceCardGeneration::                                             \
aoqi@0: oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) {                  \
aoqi@0:   blk->set_generation(this);                                                    \
aoqi@0:   _the_space->oop_since_save_marks_iterate##nv_suffix(blk);                     \
aoqi@0:   blk->reset_generation();                                                      \
aoqi@0:   save_marks();                                                                 \
aoqi@0: }
aoqi@0: 
aoqi@0: ALL_SINCE_SAVE_MARKS_CLOSURES(OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN)
aoqi@0: 
aoqi@0: #undef OneContig_SINCE_SAVE_MARKS_ITERATE_DEFN
aoqi@0: 
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::gc_epilogue(bool full) {
aoqi@0:   _last_gc = WaterMark(the_space(), the_space()->top());
aoqi@0: 
aoqi@0:   // update the generation and space performance counters
aoqi@0:   update_counters();
aoqi@0:   if (ZapUnusedHeapArea) {
aoqi@0:     the_space()->check_mangled_unused_area_complete();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::record_spaces_top() {
aoqi@0:   assert(ZapUnusedHeapArea, "Not mangling unused space");
aoqi@0:   the_space()->set_top_for_allocations();
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::verify() {
aoqi@0:   the_space()->verify();
aoqi@0: }
aoqi@0: 
aoqi@0: void OneContigSpaceCardGeneration::print_on(outputStream* st)  const {
aoqi@0:   Generation::print_on(st);
aoqi@0:   st->print("   the");
aoqi@0:   the_space()->print_on(st);
aoqi@0: }