| /* |
| * 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); |
| } |