| /* |
| * Copyright (c) 2013, 2020, Red Hat, Inc. 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 "memory/allocation.hpp" |
| #include "memory/universe.hpp" |
| |
| #include "gc/shared/gcArguments.hpp" |
| #include "gc/shared/gcTimer.hpp" |
| #include "gc/shared/gcTraceTime.inline.hpp" |
| #include "gc/shared/locationPrinter.inline.hpp" |
| #include "gc/shared/memAllocator.hpp" |
| #include "gc/shared/oopStorageSet.hpp" |
| #include "gc/shared/plab.hpp" |
| |
| #include "gc/shenandoah/shenandoahBarrierSet.hpp" |
| #include "gc/shenandoah/shenandoahClosures.inline.hpp" |
| #include "gc/shenandoah/shenandoahCollectionSet.hpp" |
| #include "gc/shenandoah/shenandoahCollectorPolicy.hpp" |
| #include "gc/shenandoah/shenandoahConcurrentMark.inline.hpp" |
| #include "gc/shenandoah/shenandoahConcurrentRoots.hpp" |
| #include "gc/shenandoah/shenandoahControlThread.hpp" |
| #include "gc/shenandoah/shenandoahFreeSet.hpp" |
| #include "gc/shenandoah/shenandoahPhaseTimings.hpp" |
| #include "gc/shenandoah/shenandoahHeap.inline.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegionSet.hpp" |
| #include "gc/shenandoah/shenandoahInitLogger.hpp" |
| #include "gc/shenandoah/shenandoahMarkCompact.hpp" |
| #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp" |
| #include "gc/shenandoah/shenandoahMemoryPool.hpp" |
| #include "gc/shenandoah/shenandoahMetrics.hpp" |
| #include "gc/shenandoah/shenandoahMonitoringSupport.hpp" |
| #include "gc/shenandoah/shenandoahOopClosures.inline.hpp" |
| #include "gc/shenandoah/shenandoahPacer.inline.hpp" |
| #include "gc/shenandoah/shenandoahPadding.hpp" |
| #include "gc/shenandoah/shenandoahParallelCleaning.inline.hpp" |
| #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp" |
| #include "gc/shenandoah/shenandoahStringDedup.hpp" |
| #include "gc/shenandoah/shenandoahTaskqueue.hpp" |
| #include "gc/shenandoah/shenandoahUtils.hpp" |
| #include "gc/shenandoah/shenandoahVerifier.hpp" |
| #include "gc/shenandoah/shenandoahCodeRoots.hpp" |
| #include "gc/shenandoah/shenandoahVMOperations.hpp" |
| #include "gc/shenandoah/shenandoahWorkGroup.hpp" |
| #include "gc/shenandoah/shenandoahWorkerPolicy.hpp" |
| #include "gc/shenandoah/mode/shenandoahIUMode.hpp" |
| #include "gc/shenandoah/mode/shenandoahPassiveMode.hpp" |
| #include "gc/shenandoah/mode/shenandoahSATBMode.hpp" |
| #if INCLUDE_JFR |
| #include "gc/shenandoah/shenandoahJfrSupport.hpp" |
| #endif |
| |
| #include "memory/metaspace.hpp" |
| #include "oops/compressedOops.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/globals.hpp" |
| #include "runtime/interfaceSupport.inline.hpp" |
| #include "runtime/orderAccess.hpp" |
| #include "runtime/safepointMechanism.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "services/mallocTracker.hpp" |
| #include "utilities/powerOfTwo.hpp" |
| |
| ShenandoahHeap* ShenandoahHeap::_heap = NULL; |
| |
| #ifdef ASSERT |
| template <class T> |
| void ShenandoahAssertToSpaceClosure::do_oop_work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (! CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| shenandoah_assert_not_forwarded(p, obj); |
| } |
| } |
| |
| void ShenandoahAssertToSpaceClosure::do_oop(narrowOop* p) { do_oop_work(p); } |
| void ShenandoahAssertToSpaceClosure::do_oop(oop* p) { do_oop_work(p); } |
| #endif |
| |
| class ShenandoahPretouchHeapTask : public AbstractGangTask { |
| private: |
| ShenandoahRegionIterator _regions; |
| const size_t _page_size; |
| public: |
| ShenandoahPretouchHeapTask(size_t page_size) : |
| AbstractGangTask("Shenandoah Pretouch Heap"), |
| _page_size(page_size) {} |
| |
| virtual void work(uint worker_id) { |
| ShenandoahHeapRegion* r = _regions.next(); |
| while (r != NULL) { |
| if (r->is_committed()) { |
| os::pretouch_memory(r->bottom(), r->end(), _page_size); |
| } |
| r = _regions.next(); |
| } |
| } |
| }; |
| |
| class ShenandoahPretouchBitmapTask : public AbstractGangTask { |
| private: |
| ShenandoahRegionIterator _regions; |
| char* _bitmap_base; |
| const size_t _bitmap_size; |
| const size_t _page_size; |
| public: |
| ShenandoahPretouchBitmapTask(char* bitmap_base, size_t bitmap_size, size_t page_size) : |
| AbstractGangTask("Shenandoah Pretouch Bitmap"), |
| _bitmap_base(bitmap_base), |
| _bitmap_size(bitmap_size), |
| _page_size(page_size) {} |
| |
| virtual void work(uint worker_id) { |
| ShenandoahHeapRegion* r = _regions.next(); |
| while (r != NULL) { |
| size_t start = r->index() * ShenandoahHeapRegion::region_size_bytes() / MarkBitMap::heap_map_factor(); |
| size_t end = (r->index() + 1) * ShenandoahHeapRegion::region_size_bytes() / MarkBitMap::heap_map_factor(); |
| assert (end <= _bitmap_size, "end is sane: " SIZE_FORMAT " < " SIZE_FORMAT, end, _bitmap_size); |
| |
| if (r->is_committed()) { |
| os::pretouch_memory(_bitmap_base + start, _bitmap_base + end, _page_size); |
| } |
| |
| r = _regions.next(); |
| } |
| } |
| }; |
| |
| jint ShenandoahHeap::initialize() { |
| // |
| // Figure out heap sizing |
| // |
| |
| size_t init_byte_size = InitialHeapSize; |
| size_t min_byte_size = MinHeapSize; |
| size_t max_byte_size = MaxHeapSize; |
| size_t heap_alignment = HeapAlignment; |
| |
| size_t reg_size_bytes = ShenandoahHeapRegion::region_size_bytes(); |
| |
| Universe::check_alignment(max_byte_size, reg_size_bytes, "Shenandoah heap"); |
| Universe::check_alignment(init_byte_size, reg_size_bytes, "Shenandoah heap"); |
| |
| _num_regions = ShenandoahHeapRegion::region_count(); |
| |
| // Now we know the number of regions, initialize the heuristics. |
| initialize_heuristics(); |
| |
| size_t num_committed_regions = init_byte_size / reg_size_bytes; |
| num_committed_regions = MIN2(num_committed_regions, _num_regions); |
| assert(num_committed_regions <= _num_regions, "sanity"); |
| _initial_size = num_committed_regions * reg_size_bytes; |
| |
| size_t num_min_regions = min_byte_size / reg_size_bytes; |
| num_min_regions = MIN2(num_min_regions, _num_regions); |
| assert(num_min_regions <= _num_regions, "sanity"); |
| _minimum_size = num_min_regions * reg_size_bytes; |
| |
| _committed = _initial_size; |
| |
| size_t heap_page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size(); |
| size_t bitmap_page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size(); |
| size_t region_page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size(); |
| |
| // |
| // Reserve and commit memory for heap |
| // |
| |
| ReservedHeapSpace heap_rs = Universe::reserve_heap(max_byte_size, heap_alignment); |
| initialize_reserved_region(heap_rs); |
| _heap_region = MemRegion((HeapWord*)heap_rs.base(), heap_rs.size() / HeapWordSize); |
| _heap_region_special = heap_rs.special(); |
| |
| assert((((size_t) base()) & ShenandoahHeapRegion::region_size_bytes_mask()) == 0, |
| "Misaligned heap: " PTR_FORMAT, p2i(base())); |
| |
| #if SHENANDOAH_OPTIMIZED_OBJTASK |
| // The optimized ObjArrayChunkedTask takes some bits away from the full object bits. |
| // Fail if we ever attempt to address more than we can. |
| if ((uintptr_t)heap_rs.end() >= ObjArrayChunkedTask::max_addressable()) { |
| FormatBuffer<512> buf("Shenandoah reserved [" PTR_FORMAT ", " PTR_FORMAT") for the heap, \n" |
| "but max object address is " PTR_FORMAT ". Try to reduce heap size, or try other \n" |
| "VM options that allocate heap at lower addresses (HeapBaseMinAddress, AllocateHeapAt, etc).", |
| p2i(heap_rs.base()), p2i(heap_rs.end()), ObjArrayChunkedTask::max_addressable()); |
| vm_exit_during_initialization("Fatal Error", buf); |
| } |
| #endif |
| |
| ReservedSpace sh_rs = heap_rs.first_part(max_byte_size); |
| if (!_heap_region_special) { |
| os::commit_memory_or_exit(sh_rs.base(), _initial_size, heap_alignment, false, |
| "Cannot commit heap memory"); |
| } |
| |
| // |
| // Reserve and commit memory for bitmap(s) |
| // |
| |
| _bitmap_size = MarkBitMap::compute_size(heap_rs.size()); |
| _bitmap_size = align_up(_bitmap_size, bitmap_page_size); |
| |
| size_t bitmap_bytes_per_region = reg_size_bytes / MarkBitMap::heap_map_factor(); |
| |
| guarantee(bitmap_bytes_per_region != 0, |
| "Bitmap bytes per region should not be zero"); |
| guarantee(is_power_of_2(bitmap_bytes_per_region), |
| "Bitmap bytes per region should be power of two: " SIZE_FORMAT, bitmap_bytes_per_region); |
| |
| if (bitmap_page_size > bitmap_bytes_per_region) { |
| _bitmap_regions_per_slice = bitmap_page_size / bitmap_bytes_per_region; |
| _bitmap_bytes_per_slice = bitmap_page_size; |
| } else { |
| _bitmap_regions_per_slice = 1; |
| _bitmap_bytes_per_slice = bitmap_bytes_per_region; |
| } |
| |
| guarantee(_bitmap_regions_per_slice >= 1, |
| "Should have at least one region per slice: " SIZE_FORMAT, |
| _bitmap_regions_per_slice); |
| |
| guarantee(((_bitmap_bytes_per_slice) % bitmap_page_size) == 0, |
| "Bitmap slices should be page-granular: bps = " SIZE_FORMAT ", page size = " SIZE_FORMAT, |
| _bitmap_bytes_per_slice, bitmap_page_size); |
| |
| ReservedSpace bitmap(_bitmap_size, bitmap_page_size); |
| MemTracker::record_virtual_memory_type(bitmap.base(), mtGC); |
| _bitmap_region = MemRegion((HeapWord*) bitmap.base(), bitmap.size() / HeapWordSize); |
| _bitmap_region_special = bitmap.special(); |
| |
| size_t bitmap_init_commit = _bitmap_bytes_per_slice * |
| align_up(num_committed_regions, _bitmap_regions_per_slice) / _bitmap_regions_per_slice; |
| bitmap_init_commit = MIN2(_bitmap_size, bitmap_init_commit); |
| if (!_bitmap_region_special) { |
| os::commit_memory_or_exit((char *) _bitmap_region.start(), bitmap_init_commit, bitmap_page_size, false, |
| "Cannot commit bitmap memory"); |
| } |
| |
| _marking_context = new ShenandoahMarkingContext(_heap_region, _bitmap_region, _num_regions); |
| |
| if (ShenandoahVerify) { |
| ReservedSpace verify_bitmap(_bitmap_size, bitmap_page_size); |
| if (!verify_bitmap.special()) { |
| os::commit_memory_or_exit(verify_bitmap.base(), verify_bitmap.size(), bitmap_page_size, false, |
| "Cannot commit verification bitmap memory"); |
| } |
| MemTracker::record_virtual_memory_type(verify_bitmap.base(), mtGC); |
| MemRegion verify_bitmap_region = MemRegion((HeapWord *) verify_bitmap.base(), verify_bitmap.size() / HeapWordSize); |
| _verification_bit_map.initialize(_heap_region, verify_bitmap_region); |
| _verifier = new ShenandoahVerifier(this, &_verification_bit_map); |
| } |
| |
| // Reserve aux bitmap for use in object_iterate(). We don't commit it here. |
| ReservedSpace aux_bitmap(_bitmap_size, bitmap_page_size); |
| MemTracker::record_virtual_memory_type(aux_bitmap.base(), mtGC); |
| _aux_bitmap_region = MemRegion((HeapWord*) aux_bitmap.base(), aux_bitmap.size() / HeapWordSize); |
| _aux_bitmap_region_special = aux_bitmap.special(); |
| _aux_bit_map.initialize(_heap_region, _aux_bitmap_region); |
| |
| // |
| // Create regions and region sets |
| // |
| size_t region_align = align_up(sizeof(ShenandoahHeapRegion), SHENANDOAH_CACHE_LINE_SIZE); |
| size_t region_storage_size = align_up(region_align * _num_regions, region_page_size); |
| region_storage_size = align_up(region_storage_size, os::vm_allocation_granularity()); |
| |
| ReservedSpace region_storage(region_storage_size, region_page_size); |
| MemTracker::record_virtual_memory_type(region_storage.base(), mtGC); |
| if (!region_storage.special()) { |
| os::commit_memory_or_exit(region_storage.base(), region_storage_size, region_page_size, false, |
| "Cannot commit region memory"); |
| } |
| |
| // Try to fit the collection set bitmap at lower addresses. This optimizes code generation for cset checks. |
| // Go up until a sensible limit (subject to encoding constraints) and try to reserve the space there. |
| // If not successful, bite a bullet and allocate at whatever address. |
| { |
| size_t cset_align = MAX2<size_t>(os::vm_page_size(), os::vm_allocation_granularity()); |
| size_t cset_size = align_up(((size_t) sh_rs.base() + sh_rs.size()) >> ShenandoahHeapRegion::region_size_bytes_shift(), cset_align); |
| |
| uintptr_t min = round_up_power_of_2(cset_align); |
| uintptr_t max = (1u << 30u); |
| |
| for (uintptr_t addr = min; addr <= max; addr <<= 1u) { |
| char* req_addr = (char*)addr; |
| assert(is_aligned(req_addr, cset_align), "Should be aligned"); |
| ReservedSpace cset_rs(cset_size, cset_align, false, req_addr); |
| if (cset_rs.is_reserved()) { |
| assert(cset_rs.base() == req_addr, "Allocated where requested: " PTR_FORMAT ", " PTR_FORMAT, p2i(cset_rs.base()), addr); |
| _collection_set = new ShenandoahCollectionSet(this, cset_rs, sh_rs.base()); |
| break; |
| } |
| } |
| |
| if (_collection_set == NULL) { |
| ReservedSpace cset_rs(cset_size, cset_align, false); |
| _collection_set = new ShenandoahCollectionSet(this, cset_rs, sh_rs.base()); |
| } |
| } |
| |
| _regions = NEW_C_HEAP_ARRAY(ShenandoahHeapRegion*, _num_regions, mtGC); |
| _free_set = new ShenandoahFreeSet(this, _num_regions); |
| |
| { |
| ShenandoahHeapLocker locker(lock()); |
| |
| for (size_t i = 0; i < _num_regions; i++) { |
| HeapWord* start = (HeapWord*)sh_rs.base() + ShenandoahHeapRegion::region_size_words() * i; |
| bool is_committed = i < num_committed_regions; |
| void* loc = region_storage.base() + i * region_align; |
| |
| ShenandoahHeapRegion* r = new (loc) ShenandoahHeapRegion(start, i, is_committed); |
| assert(is_aligned(r, SHENANDOAH_CACHE_LINE_SIZE), "Sanity"); |
| |
| _marking_context->initialize_top_at_mark_start(r); |
| _regions[i] = r; |
| assert(!collection_set()->is_in(i), "New region should not be in collection set"); |
| } |
| |
| // Initialize to complete |
| _marking_context->mark_complete(); |
| |
| _free_set->rebuild(); |
| } |
| |
| if (AlwaysPreTouch) { |
| // For NUMA, it is important to pre-touch the storage under bitmaps with worker threads, |
| // before initialize() below zeroes it with initializing thread. For any given region, |
| // we touch the region and the corresponding bitmaps from the same thread. |
| ShenandoahPushWorkerScope scope(workers(), _max_workers, false); |
| |
| _pretouch_heap_page_size = heap_page_size; |
| _pretouch_bitmap_page_size = bitmap_page_size; |
| |
| #ifdef LINUX |
| // UseTransparentHugePages would madvise that backing memory can be coalesced into huge |
| // pages. But, the kernel needs to know that every small page is used, in order to coalesce |
| // them into huge one. Therefore, we need to pretouch with smaller pages. |
| if (UseTransparentHugePages) { |
| _pretouch_heap_page_size = (size_t)os::vm_page_size(); |
| _pretouch_bitmap_page_size = (size_t)os::vm_page_size(); |
| } |
| #endif |
| |
| // OS memory managers may want to coalesce back-to-back pages. Make their jobs |
| // simpler by pre-touching continuous spaces (heap and bitmap) separately. |
| |
| ShenandoahPretouchBitmapTask bcl(bitmap.base(), _bitmap_size, _pretouch_bitmap_page_size); |
| _workers->run_task(&bcl); |
| |
| ShenandoahPretouchHeapTask hcl(_pretouch_heap_page_size); |
| _workers->run_task(&hcl); |
| } |
| |
| // |
| // Initialize the rest of GC subsystems |
| // |
| |
| _liveness_cache = NEW_C_HEAP_ARRAY(ShenandoahLiveData*, _max_workers, mtGC); |
| for (uint worker = 0; worker < _max_workers; worker++) { |
| _liveness_cache[worker] = NEW_C_HEAP_ARRAY(ShenandoahLiveData, _num_regions, mtGC); |
| Copy::fill_to_bytes(_liveness_cache[worker], _num_regions * sizeof(ShenandoahLiveData)); |
| } |
| |
| // There should probably be Shenandoah-specific options for these, |
| // just as there are G1-specific options. |
| { |
| ShenandoahSATBMarkQueueSet& satbqs = ShenandoahBarrierSet::satb_mark_queue_set(); |
| satbqs.set_process_completed_buffers_threshold(20); // G1SATBProcessCompletedThreshold |
| satbqs.set_buffer_enqueue_threshold_percentage(60); // G1SATBBufferEnqueueingThresholdPercent |
| } |
| |
| _monitoring_support = new ShenandoahMonitoringSupport(this); |
| _phase_timings = new ShenandoahPhaseTimings(max_workers()); |
| ShenandoahStringDedup::initialize(); |
| ShenandoahCodeRoots::initialize(); |
| |
| if (ShenandoahPacing) { |
| _pacer = new ShenandoahPacer(this); |
| _pacer->setup_for_idle(); |
| } else { |
| _pacer = NULL; |
| } |
| |
| _control_thread = new ShenandoahControlThread(); |
| |
| _ref_proc_mt_processing = ParallelRefProcEnabled && (ParallelGCThreads > 1); |
| _ref_proc_mt_discovery = _max_workers > 1; |
| |
| ShenandoahInitLogger::print(); |
| |
| return JNI_OK; |
| } |
| |
| void ShenandoahHeap::initialize_heuristics() { |
| if (ShenandoahGCMode != NULL) { |
| if (strcmp(ShenandoahGCMode, "satb") == 0) { |
| _gc_mode = new ShenandoahSATBMode(); |
| } else if (strcmp(ShenandoahGCMode, "iu") == 0) { |
| _gc_mode = new ShenandoahIUMode(); |
| } else if (strcmp(ShenandoahGCMode, "passive") == 0) { |
| _gc_mode = new ShenandoahPassiveMode(); |
| } else { |
| vm_exit_during_initialization("Unknown -XX:ShenandoahGCMode option"); |
| } |
| } else { |
| ShouldNotReachHere(); |
| } |
| _gc_mode->initialize_flags(); |
| if (_gc_mode->is_diagnostic() && !UnlockDiagnosticVMOptions) { |
| vm_exit_during_initialization( |
| err_msg("GC mode \"%s\" is diagnostic, and must be enabled via -XX:+UnlockDiagnosticVMOptions.", |
| _gc_mode->name())); |
| } |
| if (_gc_mode->is_experimental() && !UnlockExperimentalVMOptions) { |
| vm_exit_during_initialization( |
| err_msg("GC mode \"%s\" is experimental, and must be enabled via -XX:+UnlockExperimentalVMOptions.", |
| _gc_mode->name())); |
| } |
| |
| _heuristics = _gc_mode->initialize_heuristics(); |
| |
| if (_heuristics->is_diagnostic() && !UnlockDiagnosticVMOptions) { |
| vm_exit_during_initialization( |
| err_msg("Heuristics \"%s\" is diagnostic, and must be enabled via -XX:+UnlockDiagnosticVMOptions.", |
| _heuristics->name())); |
| } |
| if (_heuristics->is_experimental() && !UnlockExperimentalVMOptions) { |
| vm_exit_during_initialization( |
| err_msg("Heuristics \"%s\" is experimental, and must be enabled via -XX:+UnlockExperimentalVMOptions.", |
| _heuristics->name())); |
| } |
| } |
| |
| #ifdef _MSC_VER |
| #pragma warning( push ) |
| #pragma warning( disable:4355 ) // 'this' : used in base member initializer list |
| #endif |
| |
| ShenandoahHeap::ShenandoahHeap(ShenandoahCollectorPolicy* policy) : |
| CollectedHeap(), |
| _initial_size(0), |
| _used(0), |
| _committed(0), |
| _bytes_allocated_since_gc_start(0), |
| _max_workers(MAX2(ConcGCThreads, ParallelGCThreads)), |
| _workers(NULL), |
| _safepoint_workers(NULL), |
| _heap_region_special(false), |
| _num_regions(0), |
| _regions(NULL), |
| _update_refs_iterator(this), |
| _control_thread(NULL), |
| _shenandoah_policy(policy), |
| _heuristics(NULL), |
| _free_set(NULL), |
| _scm(new ShenandoahConcurrentMark()), |
| _full_gc(new ShenandoahMarkCompact()), |
| _pacer(NULL), |
| _verifier(NULL), |
| _phase_timings(NULL), |
| _monitoring_support(NULL), |
| _memory_pool(NULL), |
| _stw_memory_manager("Shenandoah Pauses", "end of GC pause"), |
| _cycle_memory_manager("Shenandoah Cycles", "end of GC cycle"), |
| _gc_timer(new (ResourceObj::C_HEAP, mtGC) ConcurrentGCTimer()), |
| _soft_ref_policy(), |
| _log_min_obj_alignment_in_bytes(LogMinObjAlignmentInBytes), |
| _ref_processor(NULL), |
| _marking_context(NULL), |
| _bitmap_size(0), |
| _bitmap_regions_per_slice(0), |
| _bitmap_bytes_per_slice(0), |
| _bitmap_region_special(false), |
| _aux_bitmap_region_special(false), |
| _liveness_cache(NULL), |
| _collection_set(NULL) |
| { |
| _heap = this; |
| |
| BarrierSet::set_barrier_set(new ShenandoahBarrierSet(this)); |
| |
| _max_workers = MAX2(_max_workers, 1U); |
| _workers = new ShenandoahWorkGang("Shenandoah GC Threads", _max_workers, |
| /* are_GC_task_threads */ true, |
| /* are_ConcurrentGC_threads */ true); |
| if (_workers == NULL) { |
| vm_exit_during_initialization("Failed necessary allocation."); |
| } else { |
| _workers->initialize_workers(); |
| } |
| |
| if (ParallelGCThreads > 1) { |
| _safepoint_workers = new ShenandoahWorkGang("Safepoint Cleanup Thread", |
| ParallelGCThreads, |
| /* are_GC_task_threads */ false, |
| /* are_ConcurrentGC_threads */ false); |
| _safepoint_workers->initialize_workers(); |
| } |
| } |
| |
| #ifdef _MSC_VER |
| #pragma warning( pop ) |
| #endif |
| |
| class ShenandoahResetBitmapTask : public AbstractGangTask { |
| private: |
| ShenandoahRegionIterator _regions; |
| |
| public: |
| ShenandoahResetBitmapTask() : |
| AbstractGangTask("Parallel Reset Bitmap Task") {} |
| |
| void work(uint worker_id) { |
| ShenandoahHeapRegion* region = _regions.next(); |
| ShenandoahHeap* heap = ShenandoahHeap::heap(); |
| ShenandoahMarkingContext* const ctx = heap->marking_context(); |
| while (region != NULL) { |
| if (heap->is_bitmap_slice_committed(region)) { |
| ctx->clear_bitmap(region); |
| } |
| region = _regions.next(); |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::reset_mark_bitmap() { |
| assert_gc_workers(_workers->active_workers()); |
| mark_incomplete_marking_context(); |
| |
| ShenandoahResetBitmapTask task; |
| _workers->run_task(&task); |
| } |
| |
| void ShenandoahHeap::print_on(outputStream* st) const { |
| st->print_cr("Shenandoah Heap"); |
| st->print_cr(" " SIZE_FORMAT "%s total, " SIZE_FORMAT "%s committed, " SIZE_FORMAT "%s used", |
| byte_size_in_proper_unit(max_capacity()), proper_unit_for_byte_size(max_capacity()), |
| byte_size_in_proper_unit(committed()), proper_unit_for_byte_size(committed()), |
| byte_size_in_proper_unit(used()), proper_unit_for_byte_size(used())); |
| st->print_cr(" " SIZE_FORMAT " x " SIZE_FORMAT"%s regions", |
| num_regions(), |
| byte_size_in_proper_unit(ShenandoahHeapRegion::region_size_bytes()), |
| proper_unit_for_byte_size(ShenandoahHeapRegion::region_size_bytes())); |
| |
| st->print("Status: "); |
| if (has_forwarded_objects()) st->print("has forwarded objects, "); |
| if (is_concurrent_mark_in_progress()) st->print("marking, "); |
| if (is_evacuation_in_progress()) st->print("evacuating, "); |
| if (is_update_refs_in_progress()) st->print("updating refs, "); |
| if (is_degenerated_gc_in_progress()) st->print("degenerated gc, "); |
| if (is_full_gc_in_progress()) st->print("full gc, "); |
| if (is_full_gc_move_in_progress()) st->print("full gc move, "); |
| if (is_concurrent_weak_root_in_progress()) st->print("concurrent weak roots, "); |
| if (is_concurrent_strong_root_in_progress() && |
| !is_concurrent_weak_root_in_progress()) st->print("concurrent strong roots, "); |
| |
| if (cancelled_gc()) { |
| st->print("cancelled"); |
| } else { |
| st->print("not cancelled"); |
| } |
| st->cr(); |
| |
| st->print_cr("Reserved region:"); |
| st->print_cr(" - [" PTR_FORMAT ", " PTR_FORMAT ") ", |
| p2i(reserved_region().start()), |
| p2i(reserved_region().end())); |
| |
| ShenandoahCollectionSet* cset = collection_set(); |
| st->print_cr("Collection set:"); |
| if (cset != NULL) { |
| st->print_cr(" - map (vanilla): " PTR_FORMAT, p2i(cset->map_address())); |
| st->print_cr(" - map (biased): " PTR_FORMAT, p2i(cset->biased_map_address())); |
| } else { |
| st->print_cr(" (NULL)"); |
| } |
| |
| st->cr(); |
| MetaspaceUtils::print_on(st); |
| |
| if (Verbose) { |
| print_heap_regions_on(st); |
| } |
| } |
| |
| class ShenandoahInitWorkerGCLABClosure : public ThreadClosure { |
| public: |
| void do_thread(Thread* thread) { |
| assert(thread != NULL, "Sanity"); |
| assert(thread->is_Worker_thread(), "Only worker thread expected"); |
| ShenandoahThreadLocalData::initialize_gclab(thread); |
| } |
| }; |
| |
| void ShenandoahHeap::post_initialize() { |
| CollectedHeap::post_initialize(); |
| MutexLocker ml(Threads_lock); |
| |
| ShenandoahInitWorkerGCLABClosure init_gclabs; |
| _workers->threads_do(&init_gclabs); |
| |
| // gclab can not be initialized early during VM startup, as it can not determinate its max_size. |
| // Now, we will let WorkGang to initialize gclab when new worker is created. |
| _workers->set_initialize_gclab(); |
| |
| _scm->initialize(_max_workers); |
| _full_gc->initialize(_gc_timer); |
| |
| ref_processing_init(); |
| |
| _heuristics->initialize(); |
| |
| JFR_ONLY(ShenandoahJFRSupport::register_jfr_type_serializers()); |
| } |
| |
| size_t ShenandoahHeap::used() const { |
| return Atomic::load_acquire(&_used); |
| } |
| |
| size_t ShenandoahHeap::committed() const { |
| OrderAccess::acquire(); |
| return _committed; |
| } |
| |
| void ShenandoahHeap::increase_committed(size_t bytes) { |
| shenandoah_assert_heaplocked_or_safepoint(); |
| _committed += bytes; |
| } |
| |
| void ShenandoahHeap::decrease_committed(size_t bytes) { |
| shenandoah_assert_heaplocked_or_safepoint(); |
| _committed -= bytes; |
| } |
| |
| void ShenandoahHeap::increase_used(size_t bytes) { |
| Atomic::add(&_used, bytes); |
| } |
| |
| void ShenandoahHeap::set_used(size_t bytes) { |
| Atomic::release_store_fence(&_used, bytes); |
| } |
| |
| void ShenandoahHeap::decrease_used(size_t bytes) { |
| assert(used() >= bytes, "never decrease heap size by more than we've left"); |
| Atomic::sub(&_used, bytes); |
| } |
| |
| void ShenandoahHeap::increase_allocated(size_t bytes) { |
| Atomic::add(&_bytes_allocated_since_gc_start, bytes); |
| } |
| |
| void ShenandoahHeap::notify_mutator_alloc_words(size_t words, bool waste) { |
| size_t bytes = words * HeapWordSize; |
| if (!waste) { |
| increase_used(bytes); |
| } |
| increase_allocated(bytes); |
| if (ShenandoahPacing) { |
| control_thread()->pacing_notify_alloc(words); |
| if (waste) { |
| pacer()->claim_for_alloc(words, true); |
| } |
| } |
| } |
| |
| size_t ShenandoahHeap::capacity() const { |
| return committed(); |
| } |
| |
| size_t ShenandoahHeap::max_capacity() const { |
| return _num_regions * ShenandoahHeapRegion::region_size_bytes(); |
| } |
| |
| size_t ShenandoahHeap::min_capacity() const { |
| return _minimum_size; |
| } |
| |
| size_t ShenandoahHeap::initial_capacity() const { |
| return _initial_size; |
| } |
| |
| bool ShenandoahHeap::is_in(const void* p) const { |
| HeapWord* heap_base = (HeapWord*) base(); |
| HeapWord* last_region_end = heap_base + ShenandoahHeapRegion::region_size_words() * num_regions(); |
| return p >= heap_base && p < last_region_end; |
| } |
| |
| void ShenandoahHeap::op_uncommit(double shrink_before) { |
| assert (ShenandoahUncommit, "should be enabled"); |
| |
| // Application allocates from the beginning of the heap, and GC allocates at |
| // the end of it. It is more efficient to uncommit from the end, so that applications |
| // could enjoy the near committed regions. GC allocations are much less frequent, |
| // and therefore can accept the committing costs. |
| |
| size_t count = 0; |
| for (size_t i = num_regions(); i > 0; i--) { // care about size_t underflow |
| ShenandoahHeapRegion* r = get_region(i - 1); |
| if (r->is_empty_committed() && (r->empty_time() < shrink_before)) { |
| ShenandoahHeapLocker locker(lock()); |
| if (r->is_empty_committed()) { |
| // Do not uncommit below minimal capacity |
| if (committed() < min_capacity() + ShenandoahHeapRegion::region_size_bytes()) { |
| break; |
| } |
| |
| r->make_uncommitted(); |
| count++; |
| } |
| } |
| SpinPause(); // allow allocators to take the lock |
| } |
| |
| if (count > 0) { |
| control_thread()->notify_heap_changed(); |
| } |
| } |
| |
| HeapWord* ShenandoahHeap::allocate_from_gclab_slow(Thread* thread, size_t size) { |
| // New object should fit the GCLAB size |
| size_t min_size = MAX2(size, PLAB::min_size()); |
| |
| // Figure out size of new GCLAB, looking back at heuristics. Expand aggressively. |
| size_t new_size = ShenandoahThreadLocalData::gclab_size(thread) * 2; |
| new_size = MIN2(new_size, PLAB::max_size()); |
| new_size = MAX2(new_size, PLAB::min_size()); |
| |
| // Record new heuristic value even if we take any shortcut. This captures |
| // the case when moderately-sized objects always take a shortcut. At some point, |
| // heuristics should catch up with them. |
| ShenandoahThreadLocalData::set_gclab_size(thread, new_size); |
| |
| if (new_size < size) { |
| // New size still does not fit the object. Fall back to shared allocation. |
| // This avoids retiring perfectly good GCLABs, when we encounter a large object. |
| return NULL; |
| } |
| |
| // Retire current GCLAB, and allocate a new one. |
| PLAB* gclab = ShenandoahThreadLocalData::gclab(thread); |
| gclab->retire(); |
| |
| size_t actual_size = 0; |
| HeapWord* gclab_buf = allocate_new_gclab(min_size, new_size, &actual_size); |
| if (gclab_buf == NULL) { |
| return NULL; |
| } |
| |
| assert (size <= actual_size, "allocation should fit"); |
| |
| if (ZeroTLAB) { |
| // ..and clear it. |
| Copy::zero_to_words(gclab_buf, actual_size); |
| } else { |
| // ...and zap just allocated object. |
| #ifdef ASSERT |
| // Skip mangling the space corresponding to the object header to |
| // ensure that the returned space is not considered parsable by |
| // any concurrent GC thread. |
| size_t hdr_size = oopDesc::header_size(); |
| Copy::fill_to_words(gclab_buf + hdr_size, actual_size - hdr_size, badHeapWordVal); |
| #endif // ASSERT |
| } |
| gclab->set_buf(gclab_buf, actual_size); |
| return gclab->allocate(size); |
| } |
| |
| HeapWord* ShenandoahHeap::allocate_new_tlab(size_t min_size, |
| size_t requested_size, |
| size_t* actual_size) { |
| ShenandoahAllocRequest req = ShenandoahAllocRequest::for_tlab(min_size, requested_size); |
| HeapWord* res = allocate_memory(req); |
| if (res != NULL) { |
| *actual_size = req.actual_size(); |
| } else { |
| *actual_size = 0; |
| } |
| return res; |
| } |
| |
| HeapWord* ShenandoahHeap::allocate_new_gclab(size_t min_size, |
| size_t word_size, |
| size_t* actual_size) { |
| ShenandoahAllocRequest req = ShenandoahAllocRequest::for_gclab(min_size, word_size); |
| HeapWord* res = allocate_memory(req); |
| if (res != NULL) { |
| *actual_size = req.actual_size(); |
| } else { |
| *actual_size = 0; |
| } |
| return res; |
| } |
| |
| HeapWord* ShenandoahHeap::allocate_memory(ShenandoahAllocRequest& req) { |
| intptr_t pacer_epoch = 0; |
| bool in_new_region = false; |
| HeapWord* result = NULL; |
| |
| if (req.is_mutator_alloc()) { |
| if (ShenandoahPacing) { |
| pacer()->pace_for_alloc(req.size()); |
| pacer_epoch = pacer()->epoch(); |
| } |
| |
| if (!ShenandoahAllocFailureALot || !should_inject_alloc_failure()) { |
| result = allocate_memory_under_lock(req, in_new_region); |
| } |
| |
| // Allocation failed, block until control thread reacted, then retry allocation. |
| // |
| // It might happen that one of the threads requesting allocation would unblock |
| // way later after GC happened, only to fail the second allocation, because |
| // other threads have already depleted the free storage. In this case, a better |
| // strategy is to try again, as long as GC makes progress. |
| // |
| // Then, we need to make sure the allocation was retried after at least one |
| // Full GC, which means we want to try more than ShenandoahFullGCThreshold times. |
| |
| size_t tries = 0; |
| |
| while (result == NULL && _progress_last_gc.is_set()) { |
| tries++; |
| control_thread()->handle_alloc_failure(req); |
| result = allocate_memory_under_lock(req, in_new_region); |
| } |
| |
| while (result == NULL && tries <= ShenandoahFullGCThreshold) { |
| tries++; |
| control_thread()->handle_alloc_failure(req); |
| result = allocate_memory_under_lock(req, in_new_region); |
| } |
| |
| } else { |
| assert(req.is_gc_alloc(), "Can only accept GC allocs here"); |
| result = allocate_memory_under_lock(req, in_new_region); |
| // Do not call handle_alloc_failure() here, because we cannot block. |
| // The allocation failure would be handled by the LRB slowpath with handle_alloc_failure_evac(). |
| } |
| |
| if (in_new_region) { |
| control_thread()->notify_heap_changed(); |
| } |
| |
| if (result != NULL) { |
| size_t requested = req.size(); |
| size_t actual = req.actual_size(); |
| |
| assert (req.is_lab_alloc() || (requested == actual), |
| "Only LAB allocations are elastic: %s, requested = " SIZE_FORMAT ", actual = " SIZE_FORMAT, |
| ShenandoahAllocRequest::alloc_type_to_string(req.type()), requested, actual); |
| |
| if (req.is_mutator_alloc()) { |
| notify_mutator_alloc_words(actual, false); |
| |
| // If we requested more than we were granted, give the rest back to pacer. |
| // This only matters if we are in the same pacing epoch: do not try to unpace |
| // over the budget for the other phase. |
| if (ShenandoahPacing && (pacer_epoch > 0) && (requested > actual)) { |
| pacer()->unpace_for_alloc(pacer_epoch, requested - actual); |
| } |
| } else { |
| increase_used(actual*HeapWordSize); |
| } |
| } |
| |
| return result; |
| } |
| |
| HeapWord* ShenandoahHeap::allocate_memory_under_lock(ShenandoahAllocRequest& req, bool& in_new_region) { |
| ShenandoahHeapLocker locker(lock()); |
| return _free_set->allocate(req, in_new_region); |
| } |
| |
| HeapWord* ShenandoahHeap::mem_allocate(size_t size, |
| bool* gc_overhead_limit_was_exceeded) { |
| ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared(size); |
| return allocate_memory(req); |
| } |
| |
| MetaWord* ShenandoahHeap::satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, |
| size_t size, |
| Metaspace::MetadataType mdtype) { |
| MetaWord* result; |
| |
| // Inform metaspace OOM to GC heuristics if class unloading is possible. |
| if (heuristics()->can_unload_classes()) { |
| ShenandoahHeuristics* h = heuristics(); |
| h->record_metaspace_oom(); |
| } |
| |
| // Expand and retry allocation |
| result = loader_data->metaspace_non_null()->expand_and_allocate(size, mdtype); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // Start full GC |
| collect(GCCause::_metadata_GC_clear_soft_refs); |
| |
| // Retry allocation |
| result = loader_data->metaspace_non_null()->allocate(size, mdtype); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // Expand and retry allocation |
| result = loader_data->metaspace_non_null()->expand_and_allocate(size, mdtype); |
| if (result != NULL) { |
| return result; |
| } |
| |
| // Out of memory |
| return NULL; |
| } |
| |
| class ShenandoahConcurrentEvacuateRegionObjectClosure : public ObjectClosure { |
| private: |
| ShenandoahHeap* const _heap; |
| Thread* const _thread; |
| public: |
| ShenandoahConcurrentEvacuateRegionObjectClosure(ShenandoahHeap* heap) : |
| _heap(heap), _thread(Thread::current()) {} |
| |
| void do_object(oop p) { |
| shenandoah_assert_marked(NULL, p); |
| if (!p->is_forwarded()) { |
| _heap->evacuate_object(p, _thread); |
| } |
| } |
| }; |
| |
| class ShenandoahEvacuationTask : public AbstractGangTask { |
| private: |
| ShenandoahHeap* const _sh; |
| ShenandoahCollectionSet* const _cs; |
| bool _concurrent; |
| public: |
| ShenandoahEvacuationTask(ShenandoahHeap* sh, |
| ShenandoahCollectionSet* cs, |
| bool concurrent) : |
| AbstractGangTask("Parallel Evacuation Task"), |
| _sh(sh), |
| _cs(cs), |
| _concurrent(concurrent) |
| {} |
| |
| void work(uint worker_id) { |
| if (_concurrent) { |
| ShenandoahConcurrentWorkerSession worker_session(worker_id); |
| ShenandoahSuspendibleThreadSetJoiner stsj(ShenandoahSuspendibleWorkers); |
| ShenandoahEvacOOMScope oom_evac_scope; |
| do_work(); |
| } else { |
| ShenandoahParallelWorkerSession worker_session(worker_id); |
| ShenandoahEvacOOMScope oom_evac_scope; |
| do_work(); |
| } |
| } |
| |
| private: |
| void do_work() { |
| ShenandoahConcurrentEvacuateRegionObjectClosure cl(_sh); |
| ShenandoahHeapRegion* r; |
| while ((r =_cs->claim_next()) != NULL) { |
| assert(r->has_live(), "Region " SIZE_FORMAT " should have been reclaimed early", r->index()); |
| _sh->marked_object_iterate(r, &cl); |
| |
| if (ShenandoahPacing) { |
| _sh->pacer()->report_evac(r->used() >> LogHeapWordSize); |
| } |
| |
| if (_sh->check_cancelled_gc_and_yield(_concurrent)) { |
| break; |
| } |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::trash_cset_regions() { |
| ShenandoahHeapLocker locker(lock()); |
| |
| ShenandoahCollectionSet* set = collection_set(); |
| ShenandoahHeapRegion* r; |
| set->clear_current_index(); |
| while ((r = set->next()) != NULL) { |
| r->make_trash(); |
| } |
| collection_set()->clear(); |
| } |
| |
| void ShenandoahHeap::print_heap_regions_on(outputStream* st) const { |
| st->print_cr("Heap Regions:"); |
| st->print_cr("EU=empty-uncommitted, EC=empty-committed, R=regular, H=humongous start, HC=humongous continuation, CS=collection set, T=trash, P=pinned"); |
| st->print_cr("BTE=bottom/top/end, U=used, T=TLAB allocs, G=GCLAB allocs, S=shared allocs, L=live data"); |
| st->print_cr("R=root, CP=critical pins, TAMS=top-at-mark-start, UWM=update watermark"); |
| st->print_cr("SN=alloc sequence number"); |
| |
| for (size_t i = 0; i < num_regions(); i++) { |
| get_region(i)->print_on(st); |
| } |
| } |
| |
| void ShenandoahHeap::trash_humongous_region_at(ShenandoahHeapRegion* start) { |
| assert(start->is_humongous_start(), "reclaim regions starting with the first one"); |
| |
| oop humongous_obj = oop(start->bottom()); |
| size_t size = humongous_obj->size(); |
| size_t required_regions = ShenandoahHeapRegion::required_regions(size * HeapWordSize); |
| size_t index = start->index() + required_regions - 1; |
| |
| assert(!start->has_live(), "liveness must be zero"); |
| |
| for(size_t i = 0; i < required_regions; i++) { |
| // Reclaim from tail. Otherwise, assertion fails when printing region to trace log, |
| // as it expects that every region belongs to a humongous region starting with a humongous start region. |
| ShenandoahHeapRegion* region = get_region(index --); |
| |
| assert(region->is_humongous(), "expect correct humongous start or continuation"); |
| assert(!region->is_cset(), "Humongous region should not be in collection set"); |
| |
| region->make_trash_immediate(); |
| } |
| } |
| |
| class ShenandoahRetireGCLABClosure : public ThreadClosure { |
| public: |
| void do_thread(Thread* thread) { |
| PLAB* gclab = ShenandoahThreadLocalData::gclab(thread); |
| assert(gclab != NULL, "GCLAB should be initialized for %s", thread->name()); |
| gclab->retire(); |
| } |
| }; |
| |
| void ShenandoahHeap::make_parsable(bool retire_tlabs) { |
| if (UseTLAB) { |
| CollectedHeap::ensure_parsability(retire_tlabs); |
| } |
| ShenandoahRetireGCLABClosure cl; |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) { |
| cl.do_thread(t); |
| } |
| workers()->threads_do(&cl); |
| } |
| |
| void ShenandoahHeap::resize_tlabs() { |
| CollectedHeap::resize_all_tlabs(); |
| } |
| |
| class ShenandoahEvacuateUpdateRootsTask : public AbstractGangTask { |
| private: |
| ShenandoahRootEvacuator* _rp; |
| |
| public: |
| ShenandoahEvacuateUpdateRootsTask(ShenandoahRootEvacuator* rp) : |
| AbstractGangTask("Shenandoah evacuate and update roots"), |
| _rp(rp) {} |
| |
| void work(uint worker_id) { |
| ShenandoahParallelWorkerSession worker_session(worker_id); |
| ShenandoahEvacOOMScope oom_evac_scope; |
| ShenandoahEvacuateUpdateRootsClosure<> cl; |
| MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations); |
| _rp->roots_do(worker_id, &cl); |
| } |
| }; |
| |
| void ShenandoahHeap::evacuate_and_update_roots() { |
| #if COMPILER2_OR_JVMCI |
| DerivedPointerTable::clear(); |
| #endif |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Only iterate roots while world is stopped"); |
| { |
| // Include concurrent roots if current cycle can not process those roots concurrently |
| ShenandoahRootEvacuator rp(workers()->active_workers(), |
| ShenandoahPhaseTimings::init_evac, |
| !ShenandoahConcurrentRoots::should_do_concurrent_roots(), |
| !ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()); |
| ShenandoahEvacuateUpdateRootsTask roots_task(&rp); |
| workers()->run_task(&roots_task); |
| } |
| |
| #if COMPILER2_OR_JVMCI |
| DerivedPointerTable::update_pointers(); |
| #endif |
| } |
| |
| // Returns size in bytes |
| size_t ShenandoahHeap::unsafe_max_tlab_alloc(Thread *thread) const { |
| if (ShenandoahElasticTLAB) { |
| // With Elastic TLABs, return the max allowed size, and let the allocation path |
| // figure out the safe size for current allocation. |
| return ShenandoahHeapRegion::max_tlab_size_bytes(); |
| } else { |
| return MIN2(_free_set->unsafe_peek_free(), ShenandoahHeapRegion::max_tlab_size_bytes()); |
| } |
| } |
| |
| size_t ShenandoahHeap::max_tlab_size() const { |
| // Returns size in words |
| return ShenandoahHeapRegion::max_tlab_size_words(); |
| } |
| |
| class ShenandoahRetireAndResetGCLABClosure : public ThreadClosure { |
| public: |
| void do_thread(Thread* thread) { |
| PLAB* gclab = ShenandoahThreadLocalData::gclab(thread); |
| gclab->retire(); |
| if (ShenandoahThreadLocalData::gclab_size(thread) > 0) { |
| ShenandoahThreadLocalData::set_gclab_size(thread, 0); |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::retire_and_reset_gclabs() { |
| ShenandoahRetireAndResetGCLABClosure cl; |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) { |
| cl.do_thread(t); |
| } |
| workers()->threads_do(&cl); |
| } |
| |
| void ShenandoahHeap::collect(GCCause::Cause cause) { |
| control_thread()->request_gc(cause); |
| } |
| |
| void ShenandoahHeap::do_full_collection(bool clear_all_soft_refs) { |
| //assert(false, "Shouldn't need to do full collections"); |
| } |
| |
| HeapWord* ShenandoahHeap::block_start(const void* addr) const { |
| ShenandoahHeapRegion* r = heap_region_containing(addr); |
| if (r != NULL) { |
| return r->block_start(addr); |
| } |
| return NULL; |
| } |
| |
| bool ShenandoahHeap::block_is_obj(const HeapWord* addr) const { |
| ShenandoahHeapRegion* r = heap_region_containing(addr); |
| return r->block_is_obj(addr); |
| } |
| |
| bool ShenandoahHeap::print_location(outputStream* st, void* addr) const { |
| return BlockLocationPrinter<ShenandoahHeap>::print_location(st, addr); |
| } |
| |
| jlong ShenandoahHeap::millis_since_last_gc() { |
| double v = heuristics()->time_since_last_gc() * 1000; |
| assert(0 <= v && v <= max_jlong, "value should fit: %f", v); |
| return (jlong)v; |
| } |
| |
| void ShenandoahHeap::prepare_for_verify() { |
| if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { |
| make_parsable(false); |
| } |
| } |
| |
| void ShenandoahHeap::print_gc_threads_on(outputStream* st) const { |
| workers()->print_worker_threads_on(st); |
| if (ShenandoahStringDedup::is_enabled()) { |
| ShenandoahStringDedup::print_worker_threads_on(st); |
| } |
| } |
| |
| void ShenandoahHeap::gc_threads_do(ThreadClosure* tcl) const { |
| workers()->threads_do(tcl); |
| if (_safepoint_workers != NULL) { |
| _safepoint_workers->threads_do(tcl); |
| } |
| if (ShenandoahStringDedup::is_enabled()) { |
| ShenandoahStringDedup::threads_do(tcl); |
| } |
| } |
| |
| void ShenandoahHeap::print_tracing_info() const { |
| LogTarget(Info, gc, stats) lt; |
| if (lt.is_enabled()) { |
| ResourceMark rm; |
| LogStream ls(lt); |
| |
| phase_timings()->print_global_on(&ls); |
| |
| ls.cr(); |
| ls.cr(); |
| |
| shenandoah_policy()->print_gc_stats(&ls); |
| |
| ls.cr(); |
| ls.cr(); |
| |
| if (ShenandoahPacing) { |
| pacer()->print_on(&ls); |
| } |
| |
| ls.cr(); |
| ls.cr(); |
| } |
| } |
| |
| void ShenandoahHeap::verify(VerifyOption vo) { |
| if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) { |
| if (ShenandoahVerify) { |
| verifier()->verify_generic(vo); |
| } else { |
| // TODO: Consider allocating verification bitmaps on demand, |
| // and turn this on unconditionally. |
| } |
| } |
| } |
| size_t ShenandoahHeap::tlab_capacity(Thread *thr) const { |
| return _free_set->capacity(); |
| } |
| |
| class ObjectIterateScanRootClosure : public BasicOopIterateClosure { |
| private: |
| MarkBitMap* _bitmap; |
| Stack<oop,mtGC>* _oop_stack; |
| ShenandoahHeap* const _heap; |
| ShenandoahMarkingContext* const _marking_context; |
| |
| template <class T> |
| void do_oop_work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| if (_heap->is_concurrent_weak_root_in_progress() && !_marking_context->is_marked(obj)) { |
| // There may be dead oops in weak roots in concurrent root phase, do not touch them. |
| return; |
| } |
| obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj); |
| |
| assert(oopDesc::is_oop(obj), "must be a valid oop"); |
| if (!_bitmap->is_marked(obj)) { |
| _bitmap->mark(obj); |
| _oop_stack->push(obj); |
| } |
| } |
| } |
| public: |
| ObjectIterateScanRootClosure(MarkBitMap* bitmap, Stack<oop,mtGC>* oop_stack) : |
| _bitmap(bitmap), _oop_stack(oop_stack), _heap(ShenandoahHeap::heap()), |
| _marking_context(_heap->marking_context()) {} |
| void do_oop(oop* p) { do_oop_work(p); } |
| void do_oop(narrowOop* p) { do_oop_work(p); } |
| }; |
| |
| /* |
| * This is public API, used in preparation of object_iterate(). |
| * Since we don't do linear scan of heap in object_iterate() (see comment below), we don't |
| * need to make the heap parsable. For Shenandoah-internal linear heap scans that we can |
| * control, we call SH::make_tlabs_parsable(). |
| */ |
| void ShenandoahHeap::ensure_parsability(bool retire_tlabs) { |
| // No-op. |
| } |
| |
| /* |
| * Iterates objects in the heap. This is public API, used for, e.g., heap dumping. |
| * |
| * We cannot safely iterate objects by doing a linear scan at random points in time. Linear |
| * scanning needs to deal with dead objects, which may have dead Klass* pointers (e.g. |
| * calling oopDesc::size() would crash) or dangling reference fields (crashes) etc. Linear |
| * scanning therefore depends on having a valid marking bitmap to support it. However, we only |
| * have a valid marking bitmap after successful marking. In particular, we *don't* have a valid |
| * marking bitmap during marking, after aborted marking or during/after cleanup (when we just |
| * wiped the bitmap in preparation for next marking). |
| * |
| * For all those reasons, we implement object iteration as a single marking traversal, reporting |
| * objects as we mark+traverse through the heap, starting from GC roots. JVMTI IterateThroughHeap |
| * is allowed to report dead objects, but is not required to do so. |
| */ |
| void ShenandoahHeap::object_iterate(ObjectClosure* cl) { |
| assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints"); |
| if (!_aux_bitmap_region_special && !os::commit_memory((char*)_aux_bitmap_region.start(), _aux_bitmap_region.byte_size(), false)) { |
| log_warning(gc)("Could not commit native memory for auxiliary marking bitmap for heap iteration"); |
| return; |
| } |
| |
| // Reset bitmap |
| _aux_bit_map.clear(); |
| |
| Stack<oop,mtGC> oop_stack; |
| |
| // First, we process GC roots according to current GC cycle. This populates the work stack with initial objects. |
| ShenandoahHeapIterationRootScanner rp; |
| ObjectIterateScanRootClosure oops(&_aux_bit_map, &oop_stack); |
| |
| rp.roots_do(&oops); |
| |
| // Work through the oop stack to traverse heap. |
| while (! oop_stack.is_empty()) { |
| oop obj = oop_stack.pop(); |
| assert(oopDesc::is_oop(obj), "must be a valid oop"); |
| cl->do_object(obj); |
| obj->oop_iterate(&oops); |
| } |
| |
| assert(oop_stack.is_empty(), "should be empty"); |
| |
| if (!_aux_bitmap_region_special && !os::uncommit_memory((char*)_aux_bitmap_region.start(), _aux_bitmap_region.byte_size())) { |
| log_warning(gc)("Could not uncommit native memory for auxiliary marking bitmap for heap iteration"); |
| } |
| } |
| |
| // Keep alive an object that was loaded with AS_NO_KEEPALIVE. |
| void ShenandoahHeap::keep_alive(oop obj) { |
| if (is_concurrent_mark_in_progress()) { |
| ShenandoahBarrierSet::barrier_set()->enqueue(obj); |
| } |
| } |
| |
| void ShenandoahHeap::heap_region_iterate(ShenandoahHeapRegionClosure* blk) const { |
| for (size_t i = 0; i < num_regions(); i++) { |
| ShenandoahHeapRegion* current = get_region(i); |
| blk->heap_region_do(current); |
| } |
| } |
| |
| class ShenandoahParallelHeapRegionTask : public AbstractGangTask { |
| private: |
| ShenandoahHeap* const _heap; |
| ShenandoahHeapRegionClosure* const _blk; |
| |
| shenandoah_padding(0); |
| volatile size_t _index; |
| shenandoah_padding(1); |
| |
| public: |
| ShenandoahParallelHeapRegionTask(ShenandoahHeapRegionClosure* blk) : |
| AbstractGangTask("Parallel Region Task"), |
| _heap(ShenandoahHeap::heap()), _blk(blk), _index(0) {} |
| |
| void work(uint worker_id) { |
| ShenandoahParallelWorkerSession worker_session(worker_id); |
| size_t stride = ShenandoahParallelRegionStride; |
| |
| size_t max = _heap->num_regions(); |
| while (_index < max) { |
| size_t cur = Atomic::fetch_and_add(&_index, stride); |
| size_t start = cur; |
| size_t end = MIN2(cur + stride, max); |
| if (start >= max) break; |
| |
| for (size_t i = cur; i < end; i++) { |
| ShenandoahHeapRegion* current = _heap->get_region(i); |
| _blk->heap_region_do(current); |
| } |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const { |
| assert(blk->is_thread_safe(), "Only thread-safe closures here"); |
| if (num_regions() > ShenandoahParallelRegionStride) { |
| ShenandoahParallelHeapRegionTask task(blk); |
| workers()->run_task(&task); |
| } else { |
| heap_region_iterate(blk); |
| } |
| } |
| |
| class ShenandoahInitMarkUpdateRegionStateClosure : public ShenandoahHeapRegionClosure { |
| private: |
| ShenandoahMarkingContext* const _ctx; |
| public: |
| ShenandoahInitMarkUpdateRegionStateClosure() : _ctx(ShenandoahHeap::heap()->marking_context()) {} |
| |
| void heap_region_do(ShenandoahHeapRegion* r) { |
| assert(!r->has_live(), "Region " SIZE_FORMAT " should have no live data", r->index()); |
| if (r->is_active()) { |
| // Check if region needs updating its TAMS. We have updated it already during concurrent |
| // reset, so it is very likely we don't need to do another write here. |
| if (_ctx->top_at_mark_start(r) != r->top()) { |
| _ctx->capture_top_at_mark_start(r); |
| } |
| } else { |
| assert(_ctx->top_at_mark_start(r) == r->top(), |
| "Region " SIZE_FORMAT " should already have correct TAMS", r->index()); |
| } |
| } |
| |
| bool is_thread_safe() { return true; } |
| }; |
| |
| void ShenandoahHeap::op_init_mark() { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Should be at safepoint"); |
| assert(Thread::current()->is_VM_thread(), "can only do this in VMThread"); |
| |
| assert(marking_context()->is_bitmap_clear(), "need clear marking bitmap"); |
| assert(!marking_context()->is_complete(), "should not be complete"); |
| assert(!has_forwarded_objects(), "No forwarded objects on this path"); |
| |
| if (ShenandoahVerify) { |
| verifier()->verify_before_concmark(); |
| } |
| |
| if (VerifyBeforeGC) { |
| Universe::verify(); |
| } |
| |
| set_concurrent_mark_in_progress(true); |
| // We need to reset all TLABs because we'd lose marks on all objects allocated in them. |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::make_parsable); |
| make_parsable(true); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_update_region_states); |
| ShenandoahInitMarkUpdateRegionStateClosure cl; |
| parallel_heap_region_iterate(&cl); |
| } |
| |
| // Make above changes visible to worker threads |
| OrderAccess::fence(); |
| |
| concurrent_mark()->mark_roots(ShenandoahPhaseTimings::scan_roots); |
| |
| if (UseTLAB) { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::resize_tlabs); |
| resize_tlabs(); |
| } |
| |
| if (ShenandoahPacing) { |
| pacer()->setup_for_mark(); |
| } |
| |
| // Arm nmethods for concurrent marking. When a nmethod is about to be executed, |
| // we need to make sure that all its metadata are marked. alternative is to remark |
| // thread roots at final mark pause, but it can be potential latency killer. |
| if (ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| ShenandoahCodeRoots::arm_nmethods(); |
| } |
| } |
| |
| void ShenandoahHeap::op_mark() { |
| concurrent_mark()->mark_from_roots(); |
| } |
| |
| class ShenandoahFinalMarkUpdateRegionStateClosure : public ShenandoahHeapRegionClosure { |
| private: |
| ShenandoahMarkingContext* const _ctx; |
| ShenandoahHeapLock* const _lock; |
| |
| public: |
| ShenandoahFinalMarkUpdateRegionStateClosure() : |
| _ctx(ShenandoahHeap::heap()->complete_marking_context()), _lock(ShenandoahHeap::heap()->lock()) {} |
| |
| void heap_region_do(ShenandoahHeapRegion* r) { |
| if (r->is_active()) { |
| // All allocations past TAMS are implicitly live, adjust the region data. |
| // Bitmaps/TAMS are swapped at this point, so we need to poll complete bitmap. |
| HeapWord *tams = _ctx->top_at_mark_start(r); |
| HeapWord *top = r->top(); |
| if (top > tams) { |
| r->increase_live_data_alloc_words(pointer_delta(top, tams)); |
| } |
| |
| // We are about to select the collection set, make sure it knows about |
| // current pinning status. Also, this allows trashing more regions that |
| // now have their pinning status dropped. |
| if (r->is_pinned()) { |
| if (r->pin_count() == 0) { |
| ShenandoahHeapLocker locker(_lock); |
| r->make_unpinned(); |
| } |
| } else { |
| if (r->pin_count() > 0) { |
| ShenandoahHeapLocker locker(_lock); |
| r->make_pinned(); |
| } |
| } |
| |
| // Remember limit for updating refs. It's guaranteed that we get no |
| // from-space-refs written from here on. |
| r->set_update_watermark_at_safepoint(r->top()); |
| } else { |
| assert(!r->has_live(), "Region " SIZE_FORMAT " should have no live data", r->index()); |
| assert(_ctx->top_at_mark_start(r) == r->top(), |
| "Region " SIZE_FORMAT " should have correct TAMS", r->index()); |
| } |
| } |
| |
| bool is_thread_safe() { return true; } |
| }; |
| |
| void ShenandoahHeap::op_final_mark() { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Should be at safepoint"); |
| assert(!has_forwarded_objects(), "No forwarded objects on this path"); |
| |
| // It is critical that we |
| // evacuate roots right after finishing marking, so that we don't |
| // get unmarked objects in the roots. |
| |
| if (!cancelled_gc()) { |
| concurrent_mark()->finish_mark_from_roots(/* full_gc = */ false); |
| |
| // Marking is completed, deactivate SATB barrier |
| set_concurrent_mark_in_progress(false); |
| mark_complete_marking_context(); |
| |
| parallel_cleaning(false /* full gc*/); |
| |
| if (ShenandoahVerify) { |
| verifier()->verify_roots_no_forwarded(); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_region_states); |
| ShenandoahFinalMarkUpdateRegionStateClosure cl; |
| parallel_heap_region_iterate(&cl); |
| |
| assert_pinned_region_status(); |
| } |
| |
| // Retire the TLABs, which will force threads to reacquire their TLABs after the pause. |
| // This is needed for two reasons. Strong one: new allocations would be with new freeset, |
| // which would be outside the collection set, so no cset writes would happen there. |
| // Weaker one: new allocations would happen past update watermark, and so less work would |
| // be needed for reference updates (would update the large filler instead). |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::retire_tlabs); |
| make_parsable(true); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::choose_cset); |
| ShenandoahHeapLocker locker(lock()); |
| _collection_set->clear(); |
| heuristics()->choose_collection_set(_collection_set); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_rebuild_freeset); |
| ShenandoahHeapLocker locker(lock()); |
| _free_set->rebuild(); |
| } |
| |
| if (!is_degenerated_gc_in_progress()) { |
| prepare_concurrent_roots(); |
| prepare_concurrent_unloading(); |
| } |
| |
| // If collection set has candidates, start evacuation. |
| // Otherwise, bypass the rest of the cycle. |
| if (!collection_set()->is_empty()) { |
| ShenandoahGCPhase init_evac(ShenandoahPhaseTimings::init_evac); |
| |
| if (ShenandoahVerify) { |
| verifier()->verify_before_evacuation(); |
| } |
| |
| set_evacuation_in_progress(true); |
| // From here on, we need to update references. |
| set_has_forwarded_objects(true); |
| |
| if (!is_degenerated_gc_in_progress()) { |
| if (ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| ShenandoahCodeRoots::arm_nmethods(); |
| } |
| evacuate_and_update_roots(); |
| } |
| |
| if (ShenandoahPacing) { |
| pacer()->setup_for_evac(); |
| } |
| |
| if (ShenandoahVerify) { |
| // If OOM while evacuating/updating of roots, there is no guarantee of their consistencies |
| if (!cancelled_gc()) { |
| ShenandoahRootVerifier::RootTypes types = ShenandoahRootVerifier::None; |
| if (ShenandoahConcurrentRoots::should_do_concurrent_roots()) { |
| types = ShenandoahRootVerifier::combine(ShenandoahRootVerifier::JNIHandleRoots, ShenandoahRootVerifier::WeakRoots); |
| types = ShenandoahRootVerifier::combine(types, ShenandoahRootVerifier::CLDGRoots); |
| types = ShenandoahRootVerifier::combine(types, ShenandoahRootVerifier::StringDedupRoots); |
| } |
| |
| if (ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| types = ShenandoahRootVerifier::combine(types, ShenandoahRootVerifier::CodeRoots); |
| } |
| verifier()->verify_roots_no_forwarded_except(types); |
| } |
| verifier()->verify_during_evacuation(); |
| } |
| } else { |
| if (ShenandoahVerify) { |
| verifier()->verify_after_concmark(); |
| } |
| |
| if (VerifyAfterGC) { |
| Universe::verify(); |
| } |
| } |
| |
| } else { |
| // If this cycle was updating references, we need to keep the has_forwarded_objects |
| // flag on, for subsequent phases to deal with it. |
| concurrent_mark()->cancel(); |
| set_concurrent_mark_in_progress(false); |
| |
| if (process_references()) { |
| // Abandon reference processing right away: pre-cleaning must have failed. |
| ReferenceProcessor *rp = ref_processor(); |
| rp->disable_discovery(); |
| rp->abandon_partial_discovery(); |
| rp->verify_no_references_recorded(); |
| } |
| } |
| } |
| |
| void ShenandoahHeap::op_conc_evac() { |
| ShenandoahEvacuationTask task(this, _collection_set, true); |
| workers()->run_task(&task); |
| } |
| |
| void ShenandoahHeap::op_stw_evac() { |
| ShenandoahEvacuationTask task(this, _collection_set, false); |
| workers()->run_task(&task); |
| } |
| |
| void ShenandoahHeap::op_updaterefs() { |
| update_heap_references(true); |
| } |
| |
| void ShenandoahHeap::op_cleanup_early() { |
| free_set()->recycle_trash(); |
| } |
| |
| void ShenandoahHeap::op_cleanup_complete() { |
| free_set()->recycle_trash(); |
| } |
| |
| class ShenandoahConcurrentRootsEvacUpdateTask : public AbstractGangTask { |
| private: |
| ShenandoahVMRoots<true /*concurrent*/> _vm_roots; |
| ShenandoahClassLoaderDataRoots<true /*concurrent*/, false /*single threaded*/> _cld_roots; |
| ShenandoahConcurrentStringDedupRoots _dedup_roots; |
| |
| public: |
| ShenandoahConcurrentRootsEvacUpdateTask(ShenandoahPhaseTimings::Phase phase) : |
| AbstractGangTask("Shenandoah Evacuate/Update Concurrent Strong Roots Task"), |
| _vm_roots(phase), |
| _cld_roots(phase, ShenandoahHeap::heap()->workers()->active_workers()) {} |
| |
| void work(uint worker_id) { |
| ShenandoahConcurrentWorkerSession worker_session(worker_id); |
| ShenandoahEvacOOMScope oom; |
| { |
| // vm_roots and weak_roots are OopStorage backed roots, concurrent iteration |
| // may race against OopStorage::release() calls. |
| ShenandoahEvacUpdateOopStorageRootsClosure cl; |
| _vm_roots.oops_do<ShenandoahEvacUpdateOopStorageRootsClosure>(&cl, worker_id); |
| } |
| |
| { |
| ShenandoahEvacuateUpdateRootsClosure<> cl; |
| CLDToOopClosure clds(&cl, ClassLoaderData::_claim_strong); |
| _cld_roots.cld_do(&clds, worker_id); |
| } |
| |
| { |
| ShenandoahForwardedIsAliveClosure is_alive; |
| ShenandoahEvacuateUpdateRootsClosure<MO_RELEASE> keep_alive; |
| _dedup_roots.oops_do(&is_alive, &keep_alive, worker_id); |
| } |
| } |
| }; |
| |
| class ShenandoahEvacUpdateCleanupOopStorageRootsClosure : public BasicOopIterateClosure { |
| private: |
| ShenandoahHeap* const _heap; |
| ShenandoahMarkingContext* const _mark_context; |
| bool _evac_in_progress; |
| Thread* const _thread; |
| size_t _dead_counter; |
| |
| public: |
| ShenandoahEvacUpdateCleanupOopStorageRootsClosure(); |
| void do_oop(oop* p); |
| void do_oop(narrowOop* p); |
| |
| size_t dead_counter() const; |
| void reset_dead_counter(); |
| }; |
| |
| ShenandoahEvacUpdateCleanupOopStorageRootsClosure::ShenandoahEvacUpdateCleanupOopStorageRootsClosure() : |
| _heap(ShenandoahHeap::heap()), |
| _mark_context(ShenandoahHeap::heap()->marking_context()), |
| _evac_in_progress(ShenandoahHeap::heap()->is_evacuation_in_progress()), |
| _thread(Thread::current()), |
| _dead_counter(0) { |
| } |
| |
| void ShenandoahEvacUpdateCleanupOopStorageRootsClosure::do_oop(oop* p) { |
| const oop obj = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(obj)) { |
| if (!_mark_context->is_marked(obj)) { |
| shenandoah_assert_correct(p, obj); |
| oop old = Atomic::cmpxchg(p, obj, oop(NULL)); |
| if (obj == old) { |
| _dead_counter ++; |
| } |
| } else if (_evac_in_progress && _heap->in_collection_set(obj)) { |
| oop resolved = ShenandoahBarrierSet::resolve_forwarded_not_null(obj); |
| if (resolved == obj) { |
| resolved = _heap->evacuate_object(obj, _thread); |
| } |
| Atomic::cmpxchg(p, obj, resolved); |
| assert(_heap->cancelled_gc() || |
| _mark_context->is_marked(resolved) && !_heap->in_collection_set(resolved), |
| "Sanity"); |
| } |
| } |
| } |
| |
| void ShenandoahEvacUpdateCleanupOopStorageRootsClosure::do_oop(narrowOop* p) { |
| ShouldNotReachHere(); |
| } |
| |
| size_t ShenandoahEvacUpdateCleanupOopStorageRootsClosure::dead_counter() const { |
| return _dead_counter; |
| } |
| |
| void ShenandoahEvacUpdateCleanupOopStorageRootsClosure::reset_dead_counter() { |
| _dead_counter = 0; |
| } |
| |
| class ShenandoahIsCLDAliveClosure : public CLDClosure { |
| public: |
| void do_cld(ClassLoaderData* cld) { |
| cld->is_alive(); |
| } |
| }; |
| |
| class ShenandoahIsNMethodAliveClosure: public NMethodClosure { |
| public: |
| void do_nmethod(nmethod* n) { |
| n->is_unloading(); |
| } |
| }; |
| |
| // This task not only evacuates/updates marked weak roots, but also "NULL" |
| // dead weak roots. |
| class ShenandoahConcurrentWeakRootsEvacUpdateTask : public AbstractGangTask { |
| private: |
| ShenandoahWeakRoot<true /*concurrent*/> _jni_roots; |
| ShenandoahWeakRoot<true /*concurrent*/> _string_table_roots; |
| ShenandoahWeakRoot<true /*concurrent*/> _resolved_method_table_roots; |
| ShenandoahWeakRoot<true /*concurrent*/> _vm_roots; |
| |
| // Roots related to concurrent class unloading |
| ShenandoahClassLoaderDataRoots<true /* concurrent */, false /* single thread*/> |
| _cld_roots; |
| ShenandoahConcurrentNMethodIterator _nmethod_itr; |
| bool _concurrent_class_unloading; |
| |
| public: |
| ShenandoahConcurrentWeakRootsEvacUpdateTask(ShenandoahPhaseTimings::Phase phase) : |
| AbstractGangTask("Shenandoah Concurrent Weak Root Task"), |
| _jni_roots(OopStorageSet::jni_weak(), phase, ShenandoahPhaseTimings::JNIWeakRoots), |
| _string_table_roots(OopStorageSet::string_table_weak(), phase, ShenandoahPhaseTimings::StringTableRoots), |
| _resolved_method_table_roots(OopStorageSet::resolved_method_table_weak(), phase, ShenandoahPhaseTimings::ResolvedMethodTableRoots), |
| _vm_roots(OopStorageSet::vm_weak(), phase, ShenandoahPhaseTimings::VMWeakRoots), |
| _cld_roots(phase, ShenandoahHeap::heap()->workers()->active_workers()), |
| _nmethod_itr(ShenandoahCodeRoots::table()), |
| _concurrent_class_unloading(ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| StringTable::reset_dead_counter(); |
| ResolvedMethodTable::reset_dead_counter(); |
| if (_concurrent_class_unloading) { |
| MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
| _nmethod_itr.nmethods_do_begin(); |
| } |
| } |
| |
| ~ShenandoahConcurrentWeakRootsEvacUpdateTask() { |
| StringTable::finish_dead_counter(); |
| ResolvedMethodTable::finish_dead_counter(); |
| if (_concurrent_class_unloading) { |
| MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
| _nmethod_itr.nmethods_do_end(); |
| } |
| } |
| |
| void work(uint worker_id) { |
| ShenandoahConcurrentWorkerSession worker_session(worker_id); |
| { |
| ShenandoahEvacOOMScope oom; |
| // jni_roots and weak_roots are OopStorage backed roots, concurrent iteration |
| // may race against OopStorage::release() calls. |
| ShenandoahEvacUpdateCleanupOopStorageRootsClosure cl; |
| _jni_roots.oops_do(&cl, worker_id); |
| _vm_roots.oops_do(&cl, worker_id); |
| |
| cl.reset_dead_counter(); |
| _string_table_roots.oops_do(&cl, worker_id); |
| StringTable::inc_dead_counter(cl.dead_counter()); |
| |
| cl.reset_dead_counter(); |
| _resolved_method_table_roots.oops_do(&cl, worker_id); |
| ResolvedMethodTable::inc_dead_counter(cl.dead_counter()); |
| } |
| |
| // If we are going to perform concurrent class unloading later on, we need to |
| // cleanup the weak oops in CLD and determinate nmethod's unloading state, so that we |
| // can cleanup immediate garbage sooner. |
| if (_concurrent_class_unloading) { |
| // Applies ShenandoahIsCLDAlive closure to CLDs, native barrier will either NULL the |
| // CLD's holder or evacuate it. |
| ShenandoahIsCLDAliveClosure is_cld_alive; |
| _cld_roots.cld_do(&is_cld_alive, worker_id); |
| |
| // Applies ShenandoahIsNMethodAliveClosure to registered nmethods. |
| // The closure calls nmethod->is_unloading(). The is_unloading |
| // state is cached, therefore, during concurrent class unloading phase, |
| // we will not touch the metadata of unloading nmethods |
| ShenandoahIsNMethodAliveClosure is_nmethod_alive; |
| _nmethod_itr.nmethods_do(&is_nmethod_alive); |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::op_weak_roots() { |
| if (is_concurrent_weak_root_in_progress()) { |
| // Concurrent weak root processing |
| { |
| ShenandoahTimingsTracker t(ShenandoahPhaseTimings::conc_weak_roots_work); |
| ShenandoahGCWorkerPhase worker_phase(ShenandoahPhaseTimings::conc_weak_roots_work); |
| ShenandoahConcurrentWeakRootsEvacUpdateTask task(ShenandoahPhaseTimings::conc_weak_roots_work); |
| workers()->run_task(&task); |
| if (!ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| set_concurrent_weak_root_in_progress(false); |
| } |
| } |
| |
| // Perform handshake to flush out dead oops |
| { |
| ShenandoahTimingsTracker t(ShenandoahPhaseTimings::conc_weak_roots_rendezvous); |
| ShenandoahRendezvousClosure cl; |
| Handshake::execute(&cl); |
| } |
| } |
| } |
| |
| void ShenandoahHeap::op_class_unloading() { |
| assert (is_concurrent_weak_root_in_progress() && |
| ShenandoahConcurrentRoots::should_do_concurrent_class_unloading(), |
| "Checked by caller"); |
| _unloader.unload(); |
| set_concurrent_weak_root_in_progress(false); |
| } |
| |
| void ShenandoahHeap::op_strong_roots() { |
| assert(is_concurrent_strong_root_in_progress(), "Checked by caller"); |
| ShenandoahConcurrentRootsEvacUpdateTask task(ShenandoahPhaseTimings::conc_strong_roots); |
| workers()->run_task(&task); |
| set_concurrent_strong_root_in_progress(false); |
| } |
| |
| class ShenandoahResetUpdateRegionStateClosure : public ShenandoahHeapRegionClosure { |
| private: |
| ShenandoahMarkingContext* const _ctx; |
| public: |
| ShenandoahResetUpdateRegionStateClosure() : _ctx(ShenandoahHeap::heap()->marking_context()) {} |
| |
| void heap_region_do(ShenandoahHeapRegion* r) { |
| if (r->is_active()) { |
| // Reset live data and set TAMS optimistically. We would recheck these under the pause |
| // anyway to capture any updates that happened since now. |
| r->clear_live_data(); |
| _ctx->capture_top_at_mark_start(r); |
| } |
| } |
| |
| bool is_thread_safe() { return true; } |
| }; |
| |
| void ShenandoahHeap::op_reset() { |
| if (ShenandoahPacing) { |
| pacer()->setup_for_reset(); |
| } |
| reset_mark_bitmap(); |
| |
| ShenandoahResetUpdateRegionStateClosure cl; |
| parallel_heap_region_iterate(&cl); |
| } |
| |
| void ShenandoahHeap::op_preclean() { |
| if (ShenandoahPacing) { |
| pacer()->setup_for_preclean(); |
| } |
| concurrent_mark()->preclean_weak_refs(); |
| } |
| |
| void ShenandoahHeap::op_full(GCCause::Cause cause) { |
| ShenandoahMetricsSnapshot metrics; |
| metrics.snap_before(); |
| |
| full_gc()->do_it(cause); |
| if (UseTLAB) { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::full_gc_resize_tlabs); |
| resize_all_tlabs(); |
| } |
| |
| metrics.snap_after(); |
| |
| if (metrics.is_good_progress()) { |
| _progress_last_gc.set(); |
| } else { |
| // Nothing to do. Tell the allocation path that we have failed to make |
| // progress, and it can finally fail. |
| _progress_last_gc.unset(); |
| } |
| } |
| |
| void ShenandoahHeap::op_degenerated(ShenandoahDegenPoint point) { |
| // Degenerated GC is STW, but it can also fail. Current mechanics communicates |
| // GC failure via cancelled_concgc() flag. So, if we detect the failure after |
| // some phase, we have to upgrade the Degenerate GC to Full GC. |
| |
| clear_cancelled_gc(); |
| |
| ShenandoahMetricsSnapshot metrics; |
| metrics.snap_before(); |
| |
| switch (point) { |
| // The cases below form the Duff's-like device: it describes the actual GC cycle, |
| // but enters it at different points, depending on which concurrent phase had |
| // degenerated. |
| |
| case _degenerated_outside_cycle: |
| // We have degenerated from outside the cycle, which means something is bad with |
| // the heap, most probably heavy humongous fragmentation, or we are very low on free |
| // space. It makes little sense to wait for Full GC to reclaim as much as it can, when |
| // we can do the most aggressive degen cycle, which includes processing references and |
| // class unloading, unless those features are explicitly disabled. |
| // |
| // Note that we can only do this for "outside-cycle" degens, otherwise we would risk |
| // changing the cycle parameters mid-cycle during concurrent -> degenerated handover. |
| set_process_references(heuristics()->can_process_references()); |
| set_unload_classes(heuristics()->can_unload_classes()); |
| |
| op_reset(); |
| |
| op_init_mark(); |
| if (cancelled_gc()) { |
| op_degenerated_fail(); |
| return; |
| } |
| |
| case _degenerated_mark: |
| op_final_mark(); |
| if (cancelled_gc()) { |
| op_degenerated_fail(); |
| return; |
| } |
| |
| if (!has_forwarded_objects() && ShenandoahConcurrentRoots::can_do_concurrent_class_unloading()) { |
| // Disarm nmethods that armed for concurrent mark. On normal cycle, it would |
| // be disarmed while conc-roots phase is running. |
| // TODO: Call op_conc_roots() here instead |
| ShenandoahCodeRoots::disarm_nmethods(); |
| } |
| |
| op_cleanup_early(); |
| |
| case _degenerated_evac: |
| // If heuristics thinks we should do the cycle, this flag would be set, |
| // and we can do evacuation. Otherwise, it would be the shortcut cycle. |
| if (is_evacuation_in_progress()) { |
| |
| // Degeneration under oom-evac protocol might have left some objects in |
| // collection set un-evacuated. Restart evacuation from the beginning to |
| // capture all objects. For all the objects that are already evacuated, |
| // it would be a simple check, which is supposed to be fast. This is also |
| // safe to do even without degeneration, as CSet iterator is at beginning |
| // in preparation for evacuation anyway. |
| // |
| // Before doing that, we need to make sure we never had any cset-pinned |
| // regions. This may happen if allocation failure happened when evacuating |
| // the about-to-be-pinned object, oom-evac protocol left the object in |
| // the collection set, and then the pin reached the cset region. If we continue |
| // the cycle here, we would trash the cset and alive objects in it. To avoid |
| // it, we fail degeneration right away and slide into Full GC to recover. |
| |
| { |
| sync_pinned_region_status(); |
| collection_set()->clear_current_index(); |
| |
| ShenandoahHeapRegion* r; |
| while ((r = collection_set()->next()) != NULL) { |
| if (r->is_pinned()) { |
| cancel_gc(GCCause::_shenandoah_upgrade_to_full_gc); |
| op_degenerated_fail(); |
| return; |
| } |
| } |
| |
| collection_set()->clear_current_index(); |
| } |
| |
| op_stw_evac(); |
| if (cancelled_gc()) { |
| op_degenerated_fail(); |
| return; |
| } |
| } |
| |
| // If heuristics thinks we should do the cycle, this flag would be set, |
| // and we need to do update-refs. Otherwise, it would be the shortcut cycle. |
| if (has_forwarded_objects()) { |
| op_init_updaterefs(); |
| if (cancelled_gc()) { |
| op_degenerated_fail(); |
| return; |
| } |
| } |
| |
| case _degenerated_updaterefs: |
| if (has_forwarded_objects()) { |
| op_final_updaterefs(); |
| if (cancelled_gc()) { |
| op_degenerated_fail(); |
| return; |
| } |
| } |
| |
| op_cleanup_complete(); |
| break; |
| |
| default: |
| ShouldNotReachHere(); |
| } |
| |
| if (ShenandoahVerify) { |
| verifier()->verify_after_degenerated(); |
| } |
| |
| if (VerifyAfterGC) { |
| Universe::verify(); |
| } |
| |
| metrics.snap_after(); |
| |
| // Check for futility and fail. There is no reason to do several back-to-back Degenerated cycles, |
| // because that probably means the heap is overloaded and/or fragmented. |
| if (!metrics.is_good_progress()) { |
| _progress_last_gc.unset(); |
| cancel_gc(GCCause::_shenandoah_upgrade_to_full_gc); |
| op_degenerated_futile(); |
| } else { |
| _progress_last_gc.set(); |
| } |
| } |
| |
| void ShenandoahHeap::op_degenerated_fail() { |
| log_info(gc)("Cannot finish degeneration, upgrading to Full GC"); |
| shenandoah_policy()->record_degenerated_upgrade_to_full(); |
| op_full(GCCause::_shenandoah_upgrade_to_full_gc); |
| } |
| |
| void ShenandoahHeap::op_degenerated_futile() { |
| shenandoah_policy()->record_degenerated_upgrade_to_full(); |
| op_full(GCCause::_shenandoah_upgrade_to_full_gc); |
| } |
| |
| void ShenandoahHeap::force_satb_flush_all_threads() { |
| if (!is_concurrent_mark_in_progress()) { |
| // No need to flush SATBs |
| return; |
| } |
| |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) { |
| ShenandoahThreadLocalData::set_force_satb_flush(t, true); |
| } |
| // The threads are not "acquiring" their thread-local data, but it does not |
| // hurt to "release" the updates here anyway. |
| OrderAccess::fence(); |
| } |
| |
| void ShenandoahHeap::set_gc_state_all_threads(char state) { |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) { |
| ShenandoahThreadLocalData::set_gc_state(t, state); |
| } |
| } |
| |
| void ShenandoahHeap::set_gc_state_mask(uint mask, bool value) { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Should really be Shenandoah safepoint"); |
| _gc_state.set_cond(mask, value); |
| set_gc_state_all_threads(_gc_state.raw_value()); |
| } |
| |
| void ShenandoahHeap::set_concurrent_mark_in_progress(bool in_progress) { |
| if (has_forwarded_objects()) { |
| set_gc_state_mask(MARKING | UPDATEREFS, in_progress); |
| } else { |
| set_gc_state_mask(MARKING, in_progress); |
| } |
| ShenandoahBarrierSet::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress); |
| } |
| |
| void ShenandoahHeap::set_evacuation_in_progress(bool in_progress) { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Only call this at safepoint"); |
| set_gc_state_mask(EVACUATION, in_progress); |
| } |
| |
| void ShenandoahHeap::set_concurrent_strong_root_in_progress(bool in_progress) { |
| assert(ShenandoahConcurrentRoots::can_do_concurrent_roots(), "Why set the flag?"); |
| if (in_progress) { |
| _concurrent_strong_root_in_progress.set(); |
| } else { |
| _concurrent_strong_root_in_progress.unset(); |
| } |
| } |
| |
| void ShenandoahHeap::set_concurrent_weak_root_in_progress(bool in_progress) { |
| assert(ShenandoahConcurrentRoots::can_do_concurrent_roots(), "Why set the flag?"); |
| if (in_progress) { |
| _concurrent_weak_root_in_progress.set(); |
| } else { |
| _concurrent_weak_root_in_progress.unset(); |
| } |
| } |
| |
| void ShenandoahHeap::ref_processing_init() { |
| assert(_max_workers > 0, "Sanity"); |
| |
| _ref_processor = |
| new ReferenceProcessor(&_subject_to_discovery, // is_subject_to_discovery |
| _ref_proc_mt_processing, // MT processing |
| _max_workers, // Degree of MT processing |
| _ref_proc_mt_discovery, // MT discovery |
| _max_workers, // Degree of MT discovery |
| false, // Reference discovery is not atomic |
| NULL, // No closure, should be installed before use |
| true); // Scale worker threads |
| |
| shenandoah_assert_rp_isalive_not_installed(); |
| } |
| |
| GCTracer* ShenandoahHeap::tracer() { |
| return shenandoah_policy()->tracer(); |
| } |
| |
| size_t ShenandoahHeap::tlab_used(Thread* thread) const { |
| return _free_set->used(); |
| } |
| |
| bool ShenandoahHeap::try_cancel_gc() { |
| while (true) { |
| jbyte prev = _cancelled_gc.cmpxchg(CANCELLED, CANCELLABLE); |
| if (prev == CANCELLABLE) return true; |
| else if (prev == CANCELLED) return false; |
| assert(ShenandoahSuspendibleWorkers, "should not get here when not using suspendible workers"); |
| assert(prev == NOT_CANCELLED, "must be NOT_CANCELLED"); |
| if (Thread::current()->is_Java_thread()) { |
| // We need to provide a safepoint here, otherwise we might |
| // spin forever if a SP is pending. |
| ThreadBlockInVM sp(JavaThread::current()); |
| SpinPause(); |
| } |
| } |
| } |
| |
| void ShenandoahHeap::cancel_gc(GCCause::Cause cause) { |
| if (try_cancel_gc()) { |
| FormatBuffer<> msg("Cancelling GC: %s", GCCause::to_string(cause)); |
| log_info(gc)("%s", msg.buffer()); |
| Events::log(Thread::current(), "%s", msg.buffer()); |
| } |
| } |
| |
| uint ShenandoahHeap::max_workers() { |
| return _max_workers; |
| } |
| |
| void ShenandoahHeap::stop() { |
| // The shutdown sequence should be able to terminate when GC is running. |
| |
| // Step 0. Notify policy to disable event recording. |
| _shenandoah_policy->record_shutdown(); |
| |
| // Step 1. Notify control thread that we are in shutdown. |
| // Note that we cannot do that with stop(), because stop() is blocking and waits for the actual shutdown. |
| // Doing stop() here would wait for the normal GC cycle to complete, never falling through to cancel below. |
| control_thread()->prepare_for_graceful_shutdown(); |
| |
| // Step 2. Notify GC workers that we are cancelling GC. |
| cancel_gc(GCCause::_shenandoah_stop_vm); |
| |
| // Step 3. Wait until GC worker exits normally. |
| control_thread()->stop(); |
| |
| // Step 4. Stop String Dedup thread if it is active |
| if (ShenandoahStringDedup::is_enabled()) { |
| ShenandoahStringDedup::stop(); |
| } |
| } |
| |
| void ShenandoahHeap::stw_unload_classes(bool full_gc) { |
| if (!unload_classes()) return; |
| |
| // Unload classes and purge SystemDictionary. |
| { |
| ShenandoahGCPhase phase(full_gc ? |
| ShenandoahPhaseTimings::full_gc_purge_class_unload : |
| ShenandoahPhaseTimings::purge_class_unload); |
| bool purged_class = SystemDictionary::do_unloading(gc_timer()); |
| |
| ShenandoahIsAliveSelector is_alive; |
| uint num_workers = _workers->active_workers(); |
| ShenandoahClassUnloadingTask unlink_task(is_alive.is_alive_closure(), num_workers, purged_class); |
| _workers->run_task(&unlink_task); |
| } |
| |
| { |
| ShenandoahGCPhase phase(full_gc ? |
| ShenandoahPhaseTimings::full_gc_purge_cldg : |
| ShenandoahPhaseTimings::purge_cldg); |
| ClassLoaderDataGraph::purge(); |
| } |
| // Resize and verify metaspace |
| MetaspaceGC::compute_new_size(); |
| MetaspaceUtils::verify_metrics(); |
| } |
| |
| // Weak roots are either pre-evacuated (final mark) or updated (final updaterefs), |
| // so they should not have forwarded oops. |
| // However, we do need to "null" dead oops in the roots, if can not be done |
| // in concurrent cycles. |
| void ShenandoahHeap::stw_process_weak_roots(bool full_gc) { |
| ShenandoahGCPhase root_phase(full_gc ? |
| ShenandoahPhaseTimings::full_gc_purge : |
| ShenandoahPhaseTimings::purge); |
| uint num_workers = _workers->active_workers(); |
| ShenandoahPhaseTimings::Phase timing_phase = full_gc ? |
| ShenandoahPhaseTimings::full_gc_purge_weak_par : |
| ShenandoahPhaseTimings::purge_weak_par; |
| ShenandoahGCPhase phase(timing_phase); |
| ShenandoahGCWorkerPhase worker_phase(timing_phase); |
| |
| // Cleanup weak roots |
| if (has_forwarded_objects()) { |
| ShenandoahForwardedIsAliveClosure is_alive; |
| ShenandoahUpdateRefsClosure keep_alive; |
| ShenandoahParallelWeakRootsCleaningTask<ShenandoahForwardedIsAliveClosure, ShenandoahUpdateRefsClosure> |
| cleaning_task(timing_phase, &is_alive, &keep_alive, num_workers, !ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()); |
| _workers->run_task(&cleaning_task); |
| } else { |
| ShenandoahIsAliveClosure is_alive; |
| #ifdef ASSERT |
| ShenandoahAssertNotForwardedClosure verify_cl; |
| ShenandoahParallelWeakRootsCleaningTask<ShenandoahIsAliveClosure, ShenandoahAssertNotForwardedClosure> |
| cleaning_task(timing_phase, &is_alive, &verify_cl, num_workers, !ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()); |
| #else |
| ShenandoahParallelWeakRootsCleaningTask<ShenandoahIsAliveClosure, DoNothingClosure> |
| cleaning_task(timing_phase, &is_alive, &do_nothing_cl, num_workers, !ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()); |
| #endif |
| _workers->run_task(&cleaning_task); |
| } |
| } |
| |
| void ShenandoahHeap::parallel_cleaning(bool full_gc) { |
| assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); |
| stw_process_weak_roots(full_gc); |
| if (!ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| stw_unload_classes(full_gc); |
| } |
| } |
| |
| void ShenandoahHeap::set_has_forwarded_objects(bool cond) { |
| set_gc_state_mask(HAS_FORWARDED, cond); |
| } |
| |
| void ShenandoahHeap::set_process_references(bool pr) { |
| _process_references.set_cond(pr); |
| } |
| |
| void ShenandoahHeap::set_unload_classes(bool uc) { |
| _unload_classes.set_cond(uc); |
| } |
| |
| bool ShenandoahHeap::process_references() const { |
| return _process_references.is_set(); |
| } |
| |
| bool ShenandoahHeap::unload_classes() const { |
| return _unload_classes.is_set(); |
| } |
| |
| address ShenandoahHeap::in_cset_fast_test_addr() { |
| ShenandoahHeap* heap = ShenandoahHeap::heap(); |
| assert(heap->collection_set() != NULL, "Sanity"); |
| return (address) heap->collection_set()->biased_map_address(); |
| } |
| |
| address ShenandoahHeap::cancelled_gc_addr() { |
| return (address) ShenandoahHeap::heap()->_cancelled_gc.addr_of(); |
| } |
| |
| address ShenandoahHeap::gc_state_addr() { |
| return (address) ShenandoahHeap::heap()->_gc_state.addr_of(); |
| } |
| |
| size_t ShenandoahHeap::bytes_allocated_since_gc_start() { |
| return Atomic::load_acquire(&_bytes_allocated_since_gc_start); |
| } |
| |
| void ShenandoahHeap::reset_bytes_allocated_since_gc_start() { |
| Atomic::release_store_fence(&_bytes_allocated_since_gc_start, (size_t)0); |
| } |
| |
| void ShenandoahHeap::set_degenerated_gc_in_progress(bool in_progress) { |
| _degenerated_gc_in_progress.set_cond(in_progress); |
| } |
| |
| void ShenandoahHeap::set_full_gc_in_progress(bool in_progress) { |
| _full_gc_in_progress.set_cond(in_progress); |
| } |
| |
| void ShenandoahHeap::set_full_gc_move_in_progress(bool in_progress) { |
| assert (is_full_gc_in_progress(), "should be"); |
| _full_gc_move_in_progress.set_cond(in_progress); |
| } |
| |
| void ShenandoahHeap::set_update_refs_in_progress(bool in_progress) { |
| set_gc_state_mask(UPDATEREFS, in_progress); |
| } |
| |
| void ShenandoahHeap::register_nmethod(nmethod* nm) { |
| ShenandoahCodeRoots::register_nmethod(nm); |
| } |
| |
| void ShenandoahHeap::unregister_nmethod(nmethod* nm) { |
| ShenandoahCodeRoots::unregister_nmethod(nm); |
| } |
| |
| void ShenandoahHeap::flush_nmethod(nmethod* nm) { |
| ShenandoahCodeRoots::flush_nmethod(nm); |
| } |
| |
| oop ShenandoahHeap::pin_object(JavaThread* thr, oop o) { |
| heap_region_containing(o)->record_pin(); |
| return o; |
| } |
| |
| void ShenandoahHeap::unpin_object(JavaThread* thr, oop o) { |
| heap_region_containing(o)->record_unpin(); |
| } |
| |
| void ShenandoahHeap::sync_pinned_region_status() { |
| ShenandoahHeapLocker locker(lock()); |
| |
| for (size_t i = 0; i < num_regions(); i++) { |
| ShenandoahHeapRegion *r = get_region(i); |
| if (r->is_active()) { |
| if (r->is_pinned()) { |
| if (r->pin_count() == 0) { |
| r->make_unpinned(); |
| } |
| } else { |
| if (r->pin_count() > 0) { |
| r->make_pinned(); |
| } |
| } |
| } |
| } |
| |
| assert_pinned_region_status(); |
| } |
| |
| #ifdef ASSERT |
| void ShenandoahHeap::assert_pinned_region_status() { |
| for (size_t i = 0; i < num_regions(); i++) { |
| ShenandoahHeapRegion* r = get_region(i); |
| assert((r->is_pinned() && r->pin_count() > 0) || (!r->is_pinned() && r->pin_count() == 0), |
| "Region " SIZE_FORMAT " pinning status is inconsistent", i); |
| } |
| } |
| #endif |
| |
| ConcurrentGCTimer* ShenandoahHeap::gc_timer() const { |
| return _gc_timer; |
| } |
| |
| void ShenandoahHeap::prepare_concurrent_roots() { |
| assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); |
| if (ShenandoahConcurrentRoots::should_do_concurrent_roots()) { |
| set_concurrent_strong_root_in_progress(!collection_set()->is_empty()); |
| set_concurrent_weak_root_in_progress(true); |
| } |
| } |
| |
| void ShenandoahHeap::prepare_concurrent_unloading() { |
| assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); |
| if (ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| _unloader.prepare(); |
| } |
| } |
| |
| void ShenandoahHeap::finish_concurrent_unloading() { |
| assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); |
| if (ShenandoahConcurrentRoots::should_do_concurrent_class_unloading()) { |
| _unloader.finish(); |
| } |
| } |
| |
| #ifdef ASSERT |
| void ShenandoahHeap::assert_gc_workers(uint nworkers) { |
| assert(nworkers > 0 && nworkers <= max_workers(), "Sanity"); |
| |
| if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) { |
| if (UseDynamicNumberOfGCThreads) { |
| assert(nworkers <= ParallelGCThreads, "Cannot use more than it has"); |
| } else { |
| // Use ParallelGCThreads inside safepoints |
| assert(nworkers == ParallelGCThreads, "Use ParallelGCThreads within safepoints"); |
| } |
| } else { |
| if (UseDynamicNumberOfGCThreads) { |
| assert(nworkers <= ConcGCThreads, "Cannot use more than it has"); |
| } else { |
| // Use ConcGCThreads outside safepoints |
| assert(nworkers == ConcGCThreads, "Use ConcGCThreads outside safepoints"); |
| } |
| } |
| } |
| #endif |
| |
| ShenandoahVerifier* ShenandoahHeap::verifier() { |
| guarantee(ShenandoahVerify, "Should be enabled"); |
| assert (_verifier != NULL, "sanity"); |
| return _verifier; |
| } |
| |
| template<class T> |
| class ShenandoahUpdateHeapRefsTask : public AbstractGangTask { |
| private: |
| T cl; |
| ShenandoahHeap* _heap; |
| ShenandoahRegionIterator* _regions; |
| bool _concurrent; |
| public: |
| ShenandoahUpdateHeapRefsTask(ShenandoahRegionIterator* regions, bool concurrent) : |
| AbstractGangTask("Concurrent Update References Task"), |
| cl(T()), |
| _heap(ShenandoahHeap::heap()), |
| _regions(regions), |
| _concurrent(concurrent) { |
| } |
| |
| void work(uint worker_id) { |
| if (_concurrent) { |
| ShenandoahConcurrentWorkerSession worker_session(worker_id); |
| ShenandoahSuspendibleThreadSetJoiner stsj(ShenandoahSuspendibleWorkers); |
| do_work(); |
| } else { |
| ShenandoahParallelWorkerSession worker_session(worker_id); |
| do_work(); |
| } |
| } |
| |
| private: |
| void do_work() { |
| ShenandoahHeapRegion* r = _regions->next(); |
| ShenandoahMarkingContext* const ctx = _heap->complete_marking_context(); |
| while (r != NULL) { |
| HeapWord* update_watermark = r->get_update_watermark(); |
| assert (update_watermark >= r->bottom(), "sanity"); |
| if (r->is_active() && !r->is_cset()) { |
| _heap->marked_object_oop_iterate(r, &cl, update_watermark); |
| } |
| if (ShenandoahPacing) { |
| _heap->pacer()->report_updaterefs(pointer_delta(update_watermark, r->bottom())); |
| } |
| if (_heap->check_cancelled_gc_and_yield(_concurrent)) { |
| return; |
| } |
| r = _regions->next(); |
| } |
| } |
| }; |
| |
| void ShenandoahHeap::update_heap_references(bool concurrent) { |
| ShenandoahUpdateHeapRefsTask<ShenandoahUpdateHeapRefsClosure> task(&_update_refs_iterator, concurrent); |
| workers()->run_task(&task); |
| } |
| |
| void ShenandoahHeap::op_init_updaterefs() { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "must be at safepoint"); |
| |
| set_evacuation_in_progress(false); |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_update_refs_retire_gclabs); |
| retire_and_reset_gclabs(); |
| } |
| |
| if (ShenandoahVerify) { |
| if (!is_degenerated_gc_in_progress()) { |
| verifier()->verify_roots_in_to_space_except(ShenandoahRootVerifier::ThreadRoots); |
| } |
| verifier()->verify_before_updaterefs(); |
| } |
| |
| set_update_refs_in_progress(true); |
| |
| _update_refs_iterator.reset(); |
| |
| if (ShenandoahPacing) { |
| pacer()->setup_for_updaterefs(); |
| } |
| } |
| |
| class ShenandoahFinalUpdateRefsUpdateRegionStateClosure : public ShenandoahHeapRegionClosure { |
| private: |
| ShenandoahHeapLock* const _lock; |
| |
| public: |
| ShenandoahFinalUpdateRefsUpdateRegionStateClosure() : _lock(ShenandoahHeap::heap()->lock()) {} |
| |
| void heap_region_do(ShenandoahHeapRegion* r) { |
| // Drop unnecessary "pinned" state from regions that does not have CP marks |
| // anymore, as this would allow trashing them. |
| |
| if (r->is_active()) { |
| if (r->is_pinned()) { |
| if (r->pin_count() == 0) { |
| ShenandoahHeapLocker locker(_lock); |
| r->make_unpinned(); |
| } |
| } else { |
| if (r->pin_count() > 0) { |
| ShenandoahHeapLocker locker(_lock); |
| r->make_pinned(); |
| } |
| } |
| } |
| } |
| |
| bool is_thread_safe() { return true; } |
| }; |
| |
| void ShenandoahHeap::op_final_updaterefs() { |
| assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "must be at safepoint"); |
| |
| finish_concurrent_unloading(); |
| |
| // Check if there is left-over work, and finish it |
| if (_update_refs_iterator.has_next()) { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs_finish_work); |
| |
| // Finish updating references where we left off. |
| clear_cancelled_gc(); |
| update_heap_references(false); |
| } |
| |
| // Clear cancelled GC, if set. On cancellation path, the block before would handle |
| // everything. On degenerated paths, cancelled gc would not be set anyway. |
| if (cancelled_gc()) { |
| clear_cancelled_gc(); |
| } |
| assert(!cancelled_gc(), "Should have been done right before"); |
| |
| if (ShenandoahVerify && !is_degenerated_gc_in_progress()) { |
| verifier()->verify_roots_in_to_space_except(ShenandoahRootVerifier::ThreadRoots); |
| } |
| |
| if (is_degenerated_gc_in_progress()) { |
| concurrent_mark()->update_roots(ShenandoahPhaseTimings::degen_gc_update_roots); |
| } else { |
| concurrent_mark()->update_thread_roots(ShenandoahPhaseTimings::final_update_refs_roots); |
| } |
| |
| // Has to be done before cset is clear |
| if (ShenandoahVerify) { |
| verifier()->verify_roots_in_to_space(); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs_update_region_states); |
| ShenandoahFinalUpdateRefsUpdateRegionStateClosure cl; |
| parallel_heap_region_iterate(&cl); |
| |
| assert_pinned_region_status(); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs_trash_cset); |
| trash_cset_regions(); |
| } |
| |
| set_has_forwarded_objects(false); |
| set_update_refs_in_progress(false); |
| |
| if (ShenandoahVerify) { |
| verifier()->verify_after_updaterefs(); |
| } |
| |
| if (VerifyAfterGC) { |
| Universe::verify(); |
| } |
| |
| { |
| ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs_rebuild_freeset); |
| ShenandoahHeapLocker locker(lock()); |
| _free_set->rebuild(); |
| } |
| } |
| |
| void ShenandoahHeap::print_extended_on(outputStream *st) const { |
| print_on(st); |
| print_heap_regions_on(st); |
| } |
| |
| bool ShenandoahHeap::is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self) { |
| size_t slice = r->index() / _bitmap_regions_per_slice; |
| |
| size_t regions_from = _bitmap_regions_per_slice * slice; |
| size_t regions_to = MIN2(num_regions(), _bitmap_regions_per_slice * (slice + 1)); |
| for (size_t g = regions_from; g < regions_to; g++) { |
| assert (g / _bitmap_regions_per_slice == slice, "same slice"); |
| if (skip_self && g == r->index()) continue; |
| if (get_region(g)->is_committed()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool ShenandoahHeap::commit_bitmap_slice(ShenandoahHeapRegion* r) { |
| shenandoah_assert_heaplocked(); |
| |
| // Bitmaps in special regions do not need commits |
| if (_bitmap_region_special) { |
| return true; |
| } |
| |
| if (is_bitmap_slice_committed(r, true)) { |
| // Some other region from the group is already committed, meaning the bitmap |
| // slice is already committed, we exit right away. |
| return true; |
| } |
| |
| // Commit the bitmap slice: |
| size_t slice = r->index() / _bitmap_regions_per_slice; |
| size_t off = _bitmap_bytes_per_slice * slice; |
| size_t len = _bitmap_bytes_per_slice; |
| char* start = (char*) _bitmap_region.start() + off; |
| |
| if (!os::commit_memory(start, len, false)) { |
| return false; |
| } |
| |
| if (AlwaysPreTouch) { |
| os::pretouch_memory(start, start + len, _pretouch_bitmap_page_size); |
| } |
| |
| return true; |
| } |
| |
| bool ShenandoahHeap::uncommit_bitmap_slice(ShenandoahHeapRegion *r) { |
| shenandoah_assert_heaplocked(); |
| |
| // Bitmaps in special regions do not need uncommits |
| if (_bitmap_region_special) { |
| return true; |
| } |
| |
| if (is_bitmap_slice_committed(r, true)) { |
| // Some other region from the group is still committed, meaning the bitmap |
| // slice is should stay committed, exit right away. |
| return true; |
| } |
| |
| // Uncommit the bitmap slice: |
| size_t slice = r->index() / _bitmap_regions_per_slice; |
| size_t off = _bitmap_bytes_per_slice * slice; |
| size_t len = _bitmap_bytes_per_slice; |
| if (!os::uncommit_memory((char*)_bitmap_region.start() + off, len)) { |
| return false; |
| } |
| return true; |
| } |
| |
| void ShenandoahHeap::safepoint_synchronize_begin() { |
| if (ShenandoahSuspendibleWorkers || UseStringDeduplication) { |
| SuspendibleThreadSet::synchronize(); |
| } |
| } |
| |
| void ShenandoahHeap::safepoint_synchronize_end() { |
| if (ShenandoahSuspendibleWorkers || UseStringDeduplication) { |
| SuspendibleThreadSet::desynchronize(); |
| } |
| } |
| |
| void ShenandoahHeap::vmop_entry_init_mark() { |
| TraceCollectorStats tcs(monitoring_support()->stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::init_mark_gross); |
| |
| try_inject_alloc_failure(); |
| VM_ShenandoahInitMark op; |
| VMThread::execute(&op); // jump to entry_init_mark() under safepoint |
| } |
| |
| void ShenandoahHeap::vmop_entry_final_mark() { |
| TraceCollectorStats tcs(monitoring_support()->stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::final_mark_gross); |
| |
| try_inject_alloc_failure(); |
| VM_ShenandoahFinalMarkStartEvac op; |
| VMThread::execute(&op); // jump to entry_final_mark under safepoint |
| } |
| |
| void ShenandoahHeap::vmop_entry_init_updaterefs() { |
| TraceCollectorStats tcs(monitoring_support()->stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::init_update_refs_gross); |
| |
| try_inject_alloc_failure(); |
| VM_ShenandoahInitUpdateRefs op; |
| VMThread::execute(&op); |
| } |
| |
| void ShenandoahHeap::vmop_entry_final_updaterefs() { |
| TraceCollectorStats tcs(monitoring_support()->stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::final_update_refs_gross); |
| |
| try_inject_alloc_failure(); |
| VM_ShenandoahFinalUpdateRefs op; |
| VMThread::execute(&op); |
| } |
| |
| void ShenandoahHeap::vmop_entry_full(GCCause::Cause cause) { |
| TraceCollectorStats tcs(monitoring_support()->full_stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::full_gc_gross); |
| |
| try_inject_alloc_failure(); |
| VM_ShenandoahFullGC op(cause); |
| VMThread::execute(&op); |
| } |
| |
| void ShenandoahHeap::vmop_degenerated(ShenandoahDegenPoint point) { |
| TraceCollectorStats tcs(monitoring_support()->full_stw_collection_counters()); |
| ShenandoahTimingsTracker timing(ShenandoahPhaseTimings::degen_gc_gross); |
| |
| VM_ShenandoahDegeneratedGC degenerated_gc((int)point); |
| VMThread::execute(°enerated_gc); |
| } |
| |
| void ShenandoahHeap::entry_init_mark() { |
| const char* msg = init_mark_event_message(); |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::init_mark); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_init_marking(), |
| "init marking"); |
| |
| op_init_mark(); |
| } |
| |
| void ShenandoahHeap::entry_final_mark() { |
| const char* msg = final_mark_event_message(); |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::final_mark); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_final_marking(), |
| "final marking"); |
| |
| op_final_mark(); |
| } |
| |
| void ShenandoahHeap::entry_init_updaterefs() { |
| static const char* msg = "Pause Init Update Refs"; |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::init_update_refs); |
| EventMark em("%s", msg); |
| |
| // No workers used in this phase, no setup required |
| |
| op_init_updaterefs(); |
| } |
| |
| void ShenandoahHeap::entry_final_updaterefs() { |
| static const char* msg = "Pause Final Update Refs"; |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::final_update_refs); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_final_update_ref(), |
| "final reference update"); |
| |
| op_final_updaterefs(); |
| } |
| |
| void ShenandoahHeap::entry_full(GCCause::Cause cause) { |
| static const char* msg = "Pause Full"; |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::full_gc, true /* log_heap_usage */); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_fullgc(), |
| "full gc"); |
| |
| op_full(cause); |
| } |
| |
| void ShenandoahHeap::entry_degenerated(int point) { |
| ShenandoahDegenPoint dpoint = (ShenandoahDegenPoint)point; |
| const char* msg = degen_event_message(dpoint); |
| ShenandoahPausePhase gc_phase(msg, ShenandoahPhaseTimings::degen_gc, true /* log_heap_usage */); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_stw_degenerated(), |
| "stw degenerated gc"); |
| |
| set_degenerated_gc_in_progress(true); |
| op_degenerated(dpoint); |
| set_degenerated_gc_in_progress(false); |
| } |
| |
| void ShenandoahHeap::entry_mark() { |
| TraceCollectorStats tcs(monitoring_support()->concurrent_collection_counters()); |
| |
| const char* msg = conc_mark_event_message(); |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_mark); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_marking(), |
| "concurrent marking"); |
| |
| try_inject_alloc_failure(); |
| op_mark(); |
| } |
| |
| void ShenandoahHeap::entry_evac() { |
| TraceCollectorStats tcs(monitoring_support()->concurrent_collection_counters()); |
| |
| static const char* msg = "Concurrent evacuation"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_evac); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_evac(), |
| "concurrent evacuation"); |
| |
| try_inject_alloc_failure(); |
| op_conc_evac(); |
| } |
| |
| void ShenandoahHeap::entry_updaterefs() { |
| static const char* msg = "Concurrent update references"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_update_refs); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_update_ref(), |
| "concurrent reference update"); |
| |
| try_inject_alloc_failure(); |
| op_updaterefs(); |
| } |
| |
| void ShenandoahHeap::entry_weak_roots() { |
| static const char* msg = "Concurrent weak roots"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_weak_roots); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_root_processing(), |
| "concurrent weak root"); |
| |
| try_inject_alloc_failure(); |
| op_weak_roots(); |
| } |
| |
| void ShenandoahHeap::entry_class_unloading() { |
| static const char* msg = "Concurrent class unloading"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_class_unload); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_root_processing(), |
| "concurrent class unloading"); |
| |
| try_inject_alloc_failure(); |
| op_class_unloading(); |
| } |
| |
| void ShenandoahHeap::entry_strong_roots() { |
| static const char* msg = "Concurrent strong roots"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_strong_roots); |
| EventMark em("%s", msg); |
| |
| ShenandoahGCWorkerPhase worker_phase(ShenandoahPhaseTimings::conc_strong_roots); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_root_processing(), |
| "concurrent strong root"); |
| |
| try_inject_alloc_failure(); |
| op_strong_roots(); |
| } |
| |
| void ShenandoahHeap::entry_cleanup_early() { |
| static const char* msg = "Concurrent cleanup"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_cleanup_early, true /* log_heap_usage */); |
| EventMark em("%s", msg); |
| |
| // This phase does not use workers, no need for setup |
| |
| try_inject_alloc_failure(); |
| op_cleanup_early(); |
| } |
| |
| void ShenandoahHeap::entry_cleanup_complete() { |
| static const char* msg = "Concurrent cleanup"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_cleanup_complete, true /* log_heap_usage */); |
| EventMark em("%s", msg); |
| |
| // This phase does not use workers, no need for setup |
| |
| try_inject_alloc_failure(); |
| op_cleanup_complete(); |
| } |
| |
| void ShenandoahHeap::entry_reset() { |
| static const char* msg = "Concurrent reset"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_reset); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_reset(), |
| "concurrent reset"); |
| |
| try_inject_alloc_failure(); |
| op_reset(); |
| } |
| |
| void ShenandoahHeap::entry_preclean() { |
| if (ShenandoahPreclean && process_references()) { |
| static const char* msg = "Concurrent precleaning"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_preclean); |
| EventMark em("%s", msg); |
| |
| ShenandoahWorkerScope scope(workers(), |
| ShenandoahWorkerPolicy::calc_workers_for_conc_preclean(), |
| "concurrent preclean", |
| /* check_workers = */ false); |
| |
| try_inject_alloc_failure(); |
| op_preclean(); |
| } |
| } |
| |
| void ShenandoahHeap::entry_uncommit(double shrink_before) { |
| static const char *msg = "Concurrent uncommit"; |
| ShenandoahConcurrentPhase gc_phase(msg, ShenandoahPhaseTimings::conc_uncommit, true /* log_heap_usage */); |
| EventMark em("%s", msg); |
| |
| op_uncommit(shrink_before); |
| } |
| |
| void ShenandoahHeap::try_inject_alloc_failure() { |
| if (ShenandoahAllocFailureALot && !cancelled_gc() && ((os::random() % 1000) > 950)) { |
| _inject_alloc_failure.set(); |
| os::naked_short_sleep(1); |
| if (cancelled_gc()) { |
| log_info(gc)("Allocation failure was successfully injected"); |
| } |
| } |
| } |
| |
| bool ShenandoahHeap::should_inject_alloc_failure() { |
| return _inject_alloc_failure.is_set() && _inject_alloc_failure.try_unset(); |
| } |
| |
| void ShenandoahHeap::initialize_serviceability() { |
| _memory_pool = new ShenandoahMemoryPool(this); |
| _cycle_memory_manager.add_pool(_memory_pool); |
| _stw_memory_manager.add_pool(_memory_pool); |
| } |
| |
| GrowableArray<GCMemoryManager*> ShenandoahHeap::memory_managers() { |
| GrowableArray<GCMemoryManager*> memory_managers(2); |
| memory_managers.append(&_cycle_memory_manager); |
| memory_managers.append(&_stw_memory_manager); |
| return memory_managers; |
| } |
| |
| GrowableArray<MemoryPool*> ShenandoahHeap::memory_pools() { |
| GrowableArray<MemoryPool*> memory_pools(1); |
| memory_pools.append(_memory_pool); |
| return memory_pools; |
| } |
| |
| MemoryUsage ShenandoahHeap::memory_usage() { |
| return _memory_pool->get_memory_usage(); |
| } |
| |
| ShenandoahRegionIterator::ShenandoahRegionIterator() : |
| _heap(ShenandoahHeap::heap()), |
| _index(0) {} |
| |
| ShenandoahRegionIterator::ShenandoahRegionIterator(ShenandoahHeap* heap) : |
| _heap(heap), |
| _index(0) {} |
| |
| void ShenandoahRegionIterator::reset() { |
| _index = 0; |
| } |
| |
| bool ShenandoahRegionIterator::has_next() const { |
| return _index < _heap->num_regions(); |
| } |
| |
| char ShenandoahHeap::gc_state() const { |
| return _gc_state.raw_value(); |
| } |
| |
| void ShenandoahHeap::deduplicate_string(oop str) { |
| assert(java_lang_String::is_instance(str), "invariant"); |
| |
| if (ShenandoahStringDedup::is_enabled()) { |
| ShenandoahStringDedup::deduplicate(str); |
| } |
| } |
| |
| const char* ShenandoahHeap::init_mark_event_message() const { |
| assert(!has_forwarded_objects(), "Should not have forwarded objects here"); |
| |
| bool proc_refs = process_references(); |
| bool unload_cls = unload_classes(); |
| |
| if (proc_refs && unload_cls) { |
| return "Pause Init Mark (process weakrefs) (unload classes)"; |
| } else if (proc_refs) { |
| return "Pause Init Mark (process weakrefs)"; |
| } else if (unload_cls) { |
| return "Pause Init Mark (unload classes)"; |
| } else { |
| return "Pause Init Mark"; |
| } |
| } |
| |
| const char* ShenandoahHeap::final_mark_event_message() const { |
| assert(!has_forwarded_objects(), "Should not have forwarded objects here"); |
| |
| bool proc_refs = process_references(); |
| bool unload_cls = unload_classes(); |
| |
| if (proc_refs && unload_cls) { |
| return "Pause Final Mark (process weakrefs) (unload classes)"; |
| } else if (proc_refs) { |
| return "Pause Final Mark (process weakrefs)"; |
| } else if (unload_cls) { |
| return "Pause Final Mark (unload classes)"; |
| } else { |
| return "Pause Final Mark"; |
| } |
| } |
| |
| const char* ShenandoahHeap::conc_mark_event_message() const { |
| assert(!has_forwarded_objects(), "Should not have forwarded objects here"); |
| |
| bool proc_refs = process_references(); |
| bool unload_cls = unload_classes(); |
| |
| if (proc_refs && unload_cls) { |
| return "Concurrent marking (process weakrefs) (unload classes)"; |
| } else if (proc_refs) { |
| return "Concurrent marking (process weakrefs)"; |
| } else if (unload_cls) { |
| return "Concurrent marking (unload classes)"; |
| } else { |
| return "Concurrent marking"; |
| } |
| } |
| |
| const char* ShenandoahHeap::degen_event_message(ShenandoahDegenPoint point) const { |
| switch (point) { |
| case _degenerated_unset: |
| return "Pause Degenerated GC (<UNSET>)"; |
| case _degenerated_outside_cycle: |
| return "Pause Degenerated GC (Outside of Cycle)"; |
| case _degenerated_mark: |
| return "Pause Degenerated GC (Mark)"; |
| case _degenerated_evac: |
| return "Pause Degenerated GC (Evacuation)"; |
| case _degenerated_updaterefs: |
| return "Pause Degenerated GC (Update Refs)"; |
| default: |
| ShouldNotReachHere(); |
| return "ERROR"; |
| } |
| } |
| |
| ShenandoahLiveData* ShenandoahHeap::get_liveness_cache(uint worker_id) { |
| #ifdef ASSERT |
| assert(_liveness_cache != NULL, "sanity"); |
| assert(worker_id < _max_workers, "sanity"); |
| for (uint i = 0; i < num_regions(); i++) { |
| assert(_liveness_cache[worker_id][i] == 0, "liveness cache should be empty"); |
| } |
| #endif |
| return _liveness_cache[worker_id]; |
| } |
| |
| void ShenandoahHeap::flush_liveness_cache(uint worker_id) { |
| assert(worker_id < _max_workers, "sanity"); |
| assert(_liveness_cache != NULL, "sanity"); |
| ShenandoahLiveData* ld = _liveness_cache[worker_id]; |
| for (uint i = 0; i < num_regions(); i++) { |
| ShenandoahLiveData live = ld[i]; |
| if (live > 0) { |
| ShenandoahHeapRegion* r = get_region(i); |
| r->increase_live_data_gc_words(live); |
| ld[i] = 0; |
| } |
| } |
| } |