--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp Mon Dec 10 15:47:44 2018 +0100
@@ -0,0 +1,2796 @@
+/*
+ * Copyright (c) 2013, 2018, Red Hat, Inc. All rights reserved.
+ *
+ * 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 "gc/shared/gcTimer.hpp"
+#include "gc/shared/gcTraceTime.inline.hpp"
+#include "gc/shared/memAllocator.hpp"
+#include "gc/shared/parallelCleaning.hpp"
+#include "gc/shared/plab.hpp"
+
+#include "gc/shenandoah/shenandoahAllocTracker.hpp"
+#include "gc/shenandoah/shenandoahBarrierSet.hpp"
+#include "gc/shenandoah/shenandoahBrooksPointer.hpp"
+#include "gc/shenandoah/shenandoahCollectionSet.hpp"
+#include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
+#include "gc/shenandoah/shenandoahConcurrentMark.hpp"
+#include "gc/shenandoah/shenandoahConcurrentMark.inline.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.hpp"
+#include "gc/shenandoah/shenandoahHeapRegionSet.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.hpp"
+#include "gc/shenandoah/shenandoahPacer.inline.hpp"
+#include "gc/shenandoah/shenandoahRootProcessor.hpp"
+#include "gc/shenandoah/shenandoahStringDedup.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/heuristics/shenandoahAdaptiveHeuristics.hpp"
+#include "gc/shenandoah/heuristics/shenandoahAggressiveHeuristics.hpp"
+#include "gc/shenandoah/heuristics/shenandoahCompactHeuristics.hpp"
+#include "gc/shenandoah/heuristics/shenandoahPassiveHeuristics.hpp"
+#include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp"
+#include "gc/shenandoah/heuristics/shenandoahTraversalHeuristics.hpp"
+
+#include "memory/metaspace.hpp"
+#include "runtime/vmThread.hpp"
+#include "services/mallocTracker.hpp"
+
+ShenandoahUpdateRefsClosure::ShenandoahUpdateRefsClosure() : _heap(ShenandoahHeap::heap()) {}
+
+#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 ShenandoahPretouchTask : public AbstractGangTask {
+private:
+ ShenandoahRegionIterator _regions;
+ const size_t _bitmap_size;
+ const size_t _page_size;
+ char* _bitmap_base;
+public:
+ ShenandoahPretouchTask(char* bitmap_base, size_t bitmap_size, size_t page_size) :
+ AbstractGangTask("Shenandoah PreTouch"),
+ _bitmap_size(bitmap_size),
+ _page_size(page_size),
+ _bitmap_base(bitmap_base) {
+ }
+
+ virtual void work(uint worker_id) {
+ ShenandoahHeapRegion* r = _regions.next();
+ while (r != NULL) {
+ os::pretouch_memory(r->bottom(), r->end(), _page_size);
+
+ size_t start = r->region_number() * ShenandoahHeapRegion::region_size_bytes() / MarkBitMap::heap_map_factor();
+ size_t end = (r->region_number() + 1) * ShenandoahHeapRegion::region_size_bytes() / MarkBitMap::heap_map_factor();
+ assert (end <= _bitmap_size, "end is sane: " SIZE_FORMAT " < " SIZE_FORMAT, end, _bitmap_size);
+
+ os::pretouch_memory(_bitmap_base + start, _bitmap_base + end, _page_size);
+
+ r = _regions.next();
+ }
+ }
+};
+
+jint ShenandoahHeap::initialize() {
+ ShenandoahBrooksPointer::initial_checks();
+
+ initialize_heuristics();
+
+ size_t init_byte_size = collector_policy()->initial_heap_byte_size();
+ size_t max_byte_size = collector_policy()->max_heap_byte_size();
+ size_t heap_alignment = collector_policy()->heap_alignment();
+
+ if (ShenandoahAlwaysPreTouch) {
+ // Enabled pre-touch means the entire heap is committed right away.
+ init_byte_size = max_byte_size;
+ }
+
+ Universe::check_alignment(max_byte_size,
+ ShenandoahHeapRegion::region_size_bytes(),
+ "shenandoah heap");
+ Universe::check_alignment(init_byte_size,
+ ShenandoahHeapRegion::region_size_bytes(),
+ "shenandoah heap");
+
+ ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size,
+ heap_alignment);
+ initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*) (heap_rs.base() + heap_rs.size()));
+
+ ReservedSpace pgc_rs = heap_rs.first_part(max_byte_size);
+
+ _num_regions = ShenandoahHeapRegion::region_count();
+
+ size_t num_committed_regions = init_byte_size / ShenandoahHeapRegion::region_size_bytes();
+ num_committed_regions = MIN2(num_committed_regions, _num_regions);
+ assert(num_committed_regions <= _num_regions, "sanity");
+
+ _initial_size = num_committed_regions * ShenandoahHeapRegion::region_size_bytes();
+ _committed = _initial_size;
+
+ log_info(gc, heap)("Initialize Shenandoah heap with initial size " SIZE_FORMAT "%s",
+ byte_size_in_proper_unit(_initial_size), proper_unit_for_byte_size(_initial_size));
+ if (!os::commit_memory(pgc_rs.base(), _initial_size, false)) {
+ vm_exit_out_of_memory(_initial_size, OOM_MMAP_ERROR, "Shenandoah failed to initialize heap");
+ }
+
+ size_t reg_size_words = ShenandoahHeapRegion::region_size_words();
+ size_t reg_size_bytes = ShenandoahHeapRegion::region_size_bytes();
+
+ _regions = NEW_C_HEAP_ARRAY(ShenandoahHeapRegion*, _num_regions, mtGC);
+ _free_set = new ShenandoahFreeSet(this, _num_regions);
+
+ _collection_set = new ShenandoahCollectionSet(this, (HeapWord*)pgc_rs.base());
+
+ if (ShenandoahPacing) {
+ _pacer = new ShenandoahPacer(this);
+ _pacer->setup_for_idle();
+ } else {
+ _pacer = NULL;
+ }
+
+ assert((((size_t) base()) & ShenandoahHeapRegion::region_size_bytes_mask()) == 0,
+ "misaligned heap: " PTR_FORMAT, p2i(base()));
+
+ // The call below uses stuff (the SATB* things) that are in G1, but probably
+ // belong into a shared location.
+ ShenandoahBarrierSet::satb_mark_queue_set().initialize(this,
+ SATB_Q_CBL_mon,
+ 20 /*G1SATBProcessCompletedThreshold */,
+ 60 /* G1SATBBufferEnqueueingThresholdPercent */,
+ Shared_SATB_Q_lock);
+
+ // Reserve space for prev and next bitmap.
+ size_t bitmap_page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size();
+ _bitmap_size = MarkBitMap::compute_size(heap_rs.size());
+ _bitmap_size = align_up(_bitmap_size, bitmap_page_size);
+ _heap_region = MemRegion((HeapWord*) heap_rs.base(), heap_rs.size() / HeapWordSize);
+
+ 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 bitmap0(_bitmap_size, bitmap_page_size);
+ MemTracker::record_virtual_memory_type(bitmap0.base(), mtGC);
+ _bitmap_region = MemRegion((HeapWord*) bitmap0.base(), bitmap0.size() / HeapWordSize);
+
+ 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);
+ os::commit_memory_or_exit((char *) (_bitmap_region.start()), bitmap_init_commit, false,
+ "couldn't allocate initial bitmap");
+
+ size_t page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size();
+
+ if (ShenandoahVerify) {
+ ReservedSpace verify_bitmap(_bitmap_size, page_size);
+ os::commit_memory_or_exit(verify_bitmap.base(), verify_bitmap.size(), false,
+ "couldn't allocate verification bitmap");
+ 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);
+ }
+
+ _marking_context = new ShenandoahMarkingContext(_heap_region, _bitmap_region, _num_regions);
+
+ {
+ ShenandoahHeapLocker locker(lock());
+ for (size_t i = 0; i < _num_regions; i++) {
+ ShenandoahHeapRegion* r = new ShenandoahHeapRegion(this,
+ (HeapWord*) pgc_rs.base() + reg_size_words * i,
+ reg_size_words,
+ i,
+ i < num_committed_regions);
+
+ _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 (ShenandoahAlwaysPreTouch) {
+ assert (!AlwaysPreTouch, "Should have been overridden");
+
+ // 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);
+
+ log_info(gc, heap)("Parallel pretouch " SIZE_FORMAT " regions with " SIZE_FORMAT " byte pages",
+ _num_regions, page_size);
+ ShenandoahPretouchTask cl(bitmap0.base(), _bitmap_size, page_size);
+ _workers->run_task(&cl);
+ }
+
+ // 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_bit_map.initialize(_heap_region, _aux_bitmap_region);
+
+ _traversal_gc = heuristics()->can_do_traversal_gc() ?
+ new ShenandoahTraversalGC(this, _num_regions) :
+ NULL;
+
+ _monitoring_support = new ShenandoahMonitoringSupport(this);
+
+ _phase_timings = new ShenandoahPhaseTimings();
+
+ if (ShenandoahAllocationTrace) {
+ _alloc_tracker = new ShenandoahAllocTracker();
+ }
+
+ ShenandoahStringDedup::initialize();
+
+ _control_thread = new ShenandoahControlThread();
+
+ ShenandoahCodeRoots::initialize();
+
+ log_info(gc, init)("Safepointing mechanism: %s",
+ SafepointMechanism::uses_thread_local_poll() ? "thread-local poll" :
+ (SafepointMechanism::uses_global_page_poll() ? "global-page poll" : "unknown"));
+
+ _liveness_cache = NEW_C_HEAP_ARRAY(jushort*, _max_workers, mtGC);
+ for (uint worker = 0; worker < _max_workers; worker++) {
+ _liveness_cache[worker] = NEW_C_HEAP_ARRAY(jushort, _num_regions, mtGC);
+ Copy::fill_to_bytes(_liveness_cache[worker], _num_regions * sizeof(jushort));
+ }
+
+ return JNI_OK;
+}
+
+void ShenandoahHeap::initialize_heuristics() {
+ if (ShenandoahGCHeuristics != NULL) {
+ if (strcmp(ShenandoahGCHeuristics, "aggressive") == 0) {
+ _heuristics = new ShenandoahAggressiveHeuristics();
+ } else if (strcmp(ShenandoahGCHeuristics, "static") == 0) {
+ _heuristics = new ShenandoahStaticHeuristics();
+ } else if (strcmp(ShenandoahGCHeuristics, "adaptive") == 0) {
+ _heuristics = new ShenandoahAdaptiveHeuristics();
+ } else if (strcmp(ShenandoahGCHeuristics, "passive") == 0) {
+ _heuristics = new ShenandoahPassiveHeuristics();
+ } else if (strcmp(ShenandoahGCHeuristics, "compact") == 0) {
+ _heuristics = new ShenandoahCompactHeuristics();
+ } else if (strcmp(ShenandoahGCHeuristics, "traversal") == 0) {
+ _heuristics = new ShenandoahTraversalHeuristics();
+ } else {
+ vm_exit_during_initialization("Unknown -XX:ShenandoahGCHeuristics option");
+ }
+
+ 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()));
+ }
+
+ if (ShenandoahStoreValEnqueueBarrier && ShenandoahStoreValReadBarrier) {
+ vm_exit_during_initialization("Cannot use both ShenandoahStoreValEnqueueBarrier and ShenandoahStoreValReadBarrier");
+ }
+ log_info(gc, init)("Shenandoah heuristics: %s",
+ _heuristics->name());
+ } else {
+ ShouldNotReachHere();
+ }
+
+}
+
+#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),
+ _num_regions(0),
+ _regions(NULL),
+ _update_refs_iterator(this),
+ _control_thread(NULL),
+ _shenandoah_policy(policy),
+ _heuristics(NULL),
+ _free_set(NULL),
+ _scm(new ShenandoahConcurrentMark()),
+ _traversal_gc(NULL),
+ _full_gc(new ShenandoahMarkCompact()),
+ _pacer(NULL),
+ _verifier(NULL),
+ _alloc_tracker(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(),
+ _ref_processor(NULL),
+ _marking_context(NULL),
+ _collection_set(NULL)
+{
+ log_info(gc, init)("GC threads: " UINT32_FORMAT " parallel, " UINT32_FORMAT " concurrent", ParallelGCThreads, ConcGCThreads);
+ log_info(gc, init)("Reference processing: %s", ParallelRefProcEnabled ? "parallel" : "serial");
+
+ 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 */false);
+ if (_workers == NULL) {
+ vm_exit_during_initialization("Failed necessary allocation.");
+ } else {
+ _workers->initialize_workers();
+ }
+
+ if (ShenandoahParallelSafepointThreads > 1) {
+ _safepoint_workers = new ShenandoahWorkGang("Safepoint Cleanup Thread",
+ ShenandoahParallelSafepointThreads,
+ false, 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 "K total, " SIZE_FORMAT "K committed, " SIZE_FORMAT "K used",
+ capacity() / K, committed() / K, used() / K);
+ st->print_cr(" " SIZE_FORMAT " x " SIZE_FORMAT"K regions",
+ num_regions(), ShenandoahHeapRegion::region_size_bytes() / K);
+
+ 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_concurrent_traversal_in_progress()) st->print("traversal, ");
+ 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 (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()));
+
+ st->cr();
+ MetaspaceUtils::print_on(st);
+
+ if (Verbose) {
+ print_heap_regions_on(st);
+ }
+}
+
+class ShenandoahInitGCLABClosure : public ThreadClosure {
+public:
+ void do_thread(Thread* thread) {
+ if (thread != NULL && (thread->is_Java_thread() || thread->is_Worker_thread())) {
+ ShenandoahThreadLocalData::initialize_gclab(thread);
+ }
+ }
+};
+
+void ShenandoahHeap::post_initialize() {
+ CollectedHeap::post_initialize();
+ MutexLocker ml(Threads_lock);
+
+ ShenandoahInitGCLABClosure init_gclabs;
+ Threads::threads_do(&init_gclabs);
+ _workers->threads_do(&init_gclabs);
+ _safepoint_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();
+}
+
+size_t ShenandoahHeap::used() const {
+ return OrderAccess::load_acquire(&_used);
+}
+
+size_t ShenandoahHeap::committed() const {
+ OrderAccess::acquire();
+ return _committed;
+}
+
+void ShenandoahHeap::increase_committed(size_t bytes) {
+ assert_heaplock_or_safepoint();
+ _committed += bytes;
+}
+
+void ShenandoahHeap::decrease_committed(size_t bytes) {
+ assert_heaplock_or_safepoint();
+ _committed -= bytes;
+}
+
+void ShenandoahHeap::increase_used(size_t bytes) {
+ Atomic::add(bytes, &_used);
+}
+
+void ShenandoahHeap::set_used(size_t bytes) {
+ OrderAccess::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(bytes, &_used);
+}
+
+void ShenandoahHeap::increase_allocated(size_t bytes) {
+ Atomic::add(bytes, &_bytes_allocated_since_gc_start);
+}
+
+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 num_regions() * ShenandoahHeapRegion::region_size_bytes();
+}
+
+size_t ShenandoahHeap::max_capacity() const {
+ return _num_regions * ShenandoahHeapRegion::region_size_bytes();
+}
+
+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");
+
+ size_t count = 0;
+ for (size_t i = 0; i < num_regions(); i++) {
+ ShenandoahHeapRegion* r = get_region(i);
+ if (r->is_empty_committed() && (r->empty_time() < shrink_before)) {
+ ShenandoahHeapLocker locker(lock());
+ if (r->is_empty_committed()) {
+ r->make_uncommitted();
+ count++;
+ }
+ }
+ SpinPause(); // allow allocators to take the lock
+ }
+
+ if (count > 0) {
+ log_info(gc)("Uncommitted " SIZE_FORMAT "M. Heap: " SIZE_FORMAT "M reserved, " SIZE_FORMAT "M committed, " SIZE_FORMAT "M used",
+ count * ShenandoahHeapRegion::region_size_bytes() / M, capacity() / M, committed() / M, used() / M);
+ 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;
+}
+
+ShenandoahHeap* ShenandoahHeap::heap() {
+ CollectedHeap* heap = Universe::heap();
+ assert(heap != NULL, "Unitialized access to ShenandoahHeap::heap()");
+ assert(heap->kind() == CollectedHeap::Shenandoah, "not a shenandoah heap");
+ return (ShenandoahHeap*) heap;
+}
+
+ShenandoahHeap* ShenandoahHeap::heap_no_check() {
+ CollectedHeap* heap = Universe::heap();
+ return (ShenandoahHeap*) heap;
+}
+
+HeapWord* ShenandoahHeap::allocate_memory(ShenandoahAllocRequest& req) {
+ ShenandoahAllocTrace trace_alloc(req.size(), req.type());
+
+ 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.size());
+ result = allocate_memory_under_lock(req, in_new_region);
+ }
+
+ while (result == NULL && tries <= ShenandoahFullGCThreshold) {
+ tries++;
+ control_thread()->handle_alloc_failure(req.size());
+ 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 WB 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);
+}
+
+class ShenandoahMemAllocator : public MemAllocator {
+private:
+ MemAllocator& _initializer;
+public:
+ ShenandoahMemAllocator(MemAllocator& initializer, Klass* klass, size_t word_size, Thread* thread) :
+ MemAllocator(klass, word_size + ShenandoahBrooksPointer::word_size(), thread),
+ _initializer(initializer) {}
+
+protected:
+ virtual HeapWord* mem_allocate(Allocation& allocation) const {
+ HeapWord* result = MemAllocator::mem_allocate(allocation);
+ // Initialize brooks-pointer
+ if (result != NULL) {
+ result += ShenandoahBrooksPointer::word_size();
+ ShenandoahBrooksPointer::initialize(oop(result));
+ assert(! ShenandoahHeap::heap()->in_collection_set(result), "never allocate in targetted region");
+ }
+ return result;
+ }
+
+ virtual oop initialize(HeapWord* mem) const {
+ return _initializer.initialize(mem);
+ }
+};
+
+oop ShenandoahHeap::obj_allocate(Klass* klass, int size, TRAPS) {
+ ObjAllocator initializer(klass, size, THREAD);
+ ShenandoahMemAllocator allocator(initializer, klass, size, THREAD);
+ return allocator.allocate();
+}
+
+oop ShenandoahHeap::array_allocate(Klass* klass, int size, int length, bool do_zero, TRAPS) {
+ ObjArrayAllocator initializer(klass, size, length, do_zero, THREAD);
+ ShenandoahMemAllocator allocator(initializer, klass, size, THREAD);
+ return allocator.allocate();
+}
+
+oop ShenandoahHeap::class_allocate(Klass* klass, int size, TRAPS) {
+ ClassAllocator initializer(klass, size, THREAD);
+ ShenandoahMemAllocator allocator(initializer, klass, size, THREAD);
+ return allocator.allocate();
+}
+
+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;
+}
+
+void ShenandoahHeap::fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap) {
+ HeapWord* obj = tlab_post_allocation_setup(start);
+ CollectedHeap::fill_with_object(obj, end);
+}
+
+size_t ShenandoahHeap::min_dummy_object_size() const {
+ return CollectedHeap::min_dummy_object_size() + ShenandoahBrooksPointer::word_size();
+}
+
+class ShenandoahEvacuateUpdateRootsClosure: public BasicOopIterateClosure {
+private:
+ ShenandoahHeap* _heap;
+ Thread* _thread;
+public:
+ ShenandoahEvacuateUpdateRootsClosure() :
+ _heap(ShenandoahHeap::heap()), _thread(Thread::current()) {
+ }
+
+private:
+ template <class T>
+ void do_oop_work(T* p) {
+ assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
+
+ T o = RawAccess<>::oop_load(p);
+ if (! CompressedOops::is_null(o)) {
+ oop obj = CompressedOops::decode_not_null(o);
+ if (_heap->in_collection_set(obj)) {
+ shenandoah_assert_marked(p, obj);
+ oop resolved = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
+ if (oopDesc::equals_raw(resolved, obj)) {
+ resolved = _heap->evacuate_object(obj, _thread);
+ }
+ RawAccess<IS_NOT_NULL>::oop_store(p, resolved);
+ }
+ }
+ }
+
+public:
+ void do_oop(oop* p) {
+ do_oop_work(p);
+ }
+ void do_oop(narrowOop* p) {
+ do_oop_work(p);
+ }
+};
+
+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 (oopDesc::equals_raw(p, ShenandoahBarrierSet::resolve_forwarded_not_null(p))) {
+ _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(), "all-garbage regions are reclaimed early");
+ _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 (previous, next)");
+ st->print_cr("SN=alloc sequence numbers (first mutator, last mutator, first gc, last gc)");
+
+ 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() + ShenandoahBrooksPointer::word_size());
+ size_t size = humongous_obj->size() + ShenandoahBrooksPointer::word_size();
+ size_t required_regions = ShenandoahHeapRegion::required_regions(size * HeapWordSize);
+ size_t index = start->region_number() + 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);
+ _safepoint_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->process_evacuate_roots(&cl, &blobsCl, worker_id);
+ }
+};
+
+void ShenandoahHeap::evacuate_and_update_roots() {
+#if defined(COMPILER2) || INCLUDE_JVMCI
+ DerivedPointerTable::clear();
+#endif
+ assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Only iterate roots while world is stopped");
+
+ {
+ ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahPhaseTimings::init_evac);
+ ShenandoahEvacuateUpdateRootsTask roots_task(&rp);
+ workers()->run_task(&roots_task);
+ }
+
+#if defined(COMPILER2) || INCLUDE_JVMCI
+ DerivedPointerTable::update_pointers();
+#endif
+}
+
+void ShenandoahHeap::roots_iterate(OopClosure* cl) {
+ assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Only iterate roots while world is stopped");
+
+ CodeBlobToOopClosure blobsCl(cl, false);
+ CLDToOopClosure cldCl(cl, ClassLoaderData::_claim_strong);
+
+ ShenandoahRootProcessor rp(this, 1, ShenandoahPhaseTimings::_num_phases);
+ rp.process_all_roots(cl, NULL, &cldCl, &blobsCl, NULL, 0);
+}
+
+// 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);
+ _safepoint_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");
+}
+
+CollectorPolicy* ShenandoahHeap::collector_policy() const {
+ return _shenandoah_policy;
+}
+
+HeapWord* ShenandoahHeap::block_start(const void* addr) const {
+ Space* sp = heap_region_containing(addr);
+ if (sp != NULL) {
+ return sp->block_start(addr);
+ }
+ return NULL;
+}
+
+size_t ShenandoahHeap::block_size(const HeapWord* addr) const {
+ Space* sp = heap_region_containing(addr);
+ assert(sp != NULL, "block_size of address outside of heap");
+ return sp->block_size(addr);
+}
+
+bool ShenandoahHeap::block_is_obj(const HeapWord* addr) const {
+ Space* sp = heap_region_containing(addr);
+ return sp->block_is_obj(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);
+ _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_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();
+
+ if (ShenandoahAllocationTrace) {
+ assert(alloc_tracker() != NULL, "Must be");
+ alloc_tracker()->print_on(&ls);
+ } else {
+ ls.print_cr(" Allocation tracing is disabled, use -XX:+ShenandoahAllocationTrace to enable.");
+ }
+ }
+}
+
+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;
+
+ 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);
+ obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
+ assert(oopDesc::is_oop(obj), "must be a valid oop");
+ if (!_bitmap->is_marked((HeapWord*) obj)) {
+ _bitmap->mark((HeapWord*) obj);
+ _oop_stack->push(obj);
+ }
+ }
+ }
+public:
+ ObjectIterateScanRootClosure(MarkBitMap* bitmap, Stack<oop,mtGC>* oop_stack) :
+ _bitmap(bitmap), _oop_stack(oop_stack) {}
+ 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 (!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 all GC roots. This populates the work stack with initial objects.
+ ShenandoahRootProcessor rp(this, 1, ShenandoahPhaseTimings::_num_phases);
+ ObjectIterateScanRootClosure oops(&_aux_bit_map, &oop_stack);
+ CLDToOopClosure clds(&oops, ClassLoaderData::_claim_none);
+ CodeBlobToOopClosure blobs(&oops, false);
+ rp.process_all_roots(&oops, &oops, &clds, &blobs, NULL, 0);
+
+ // 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 (!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");
+ }
+}
+
+void ShenandoahHeap::safe_object_iterate(ObjectClosure* cl) {
+ assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints");
+ object_iterate(cl);
+}
+
+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;
+
+ DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
+ volatile size_t _index;
+ DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
+
+public:
+ ShenandoahParallelHeapRegionTask(ShenandoahHeapRegionClosure* blk) :
+ AbstractGangTask("Parallel Region Task"),
+ _heap(ShenandoahHeap::heap()), _blk(blk), _index(0) {}
+
+ void work(uint worker_id) {
+ size_t stride = ShenandoahParallelRegionStride;
+
+ size_t max = _heap->num_regions();
+ while (_index < max) {
+ size_t cur = Atomic::add(stride, &_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 ShenandoahClearLivenessClosure : public ShenandoahHeapRegionClosure {
+private:
+ ShenandoahMarkingContext* const _ctx;
+public:
+ ShenandoahClearLivenessClosure() : _ctx(ShenandoahHeap::heap()->marking_context()) {}
+
+ void heap_region_do(ShenandoahHeapRegion* r) {
+ if (r->is_active()) {
+ r->clear_live_data();
+ _ctx->capture_top_at_mark_start(r);
+ } else {
+ assert(!r->has_live(), "Region " SIZE_FORMAT " should have no live data", r->region_number());
+ assert(_ctx->top_at_mark_start(r) == r->top(),
+ "Region " SIZE_FORMAT " should already have correct TAMS", r->region_number());
+ }
+ }
+
+ 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");
+
+ 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::clear_liveness);
+ ShenandoahClearLivenessClosure clc;
+ parallel_heap_region_iterate(&clc);
+ }
+
+ // 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();
+ }
+}
+
+void ShenandoahHeap::op_mark() {
+ concurrent_mark()->mark_from_roots();
+}
+
+class ShenandoahCompleteLivenessClosure : public ShenandoahHeapRegionClosure {
+private:
+ ShenandoahMarkingContext* const _ctx;
+public:
+ ShenandoahCompleteLivenessClosure() : _ctx(ShenandoahHeap::heap()->complete_marking_context()) {}
+
+ void heap_region_do(ShenandoahHeapRegion* r) {
+ if (r->is_active()) {
+ 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));
+ }
+ } else {
+ assert(!r->has_live(), "Region " SIZE_FORMAT " should have no live data", r->region_number());
+ assert(_ctx->top_at_mark_start(r) == r->top(),
+ "Region " SIZE_FORMAT " should have correct TAMS", r->region_number());
+ }
+ }
+
+ bool is_thread_safe() { return true; }
+};
+
+void ShenandoahHeap::op_final_mark() {
+ assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Should be at safepoint");
+
+ // 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);
+
+ if (has_forwarded_objects()) {
+ concurrent_mark()->update_roots(ShenandoahPhaseTimings::update_roots);
+ }
+
+ stop_concurrent_marking();
+
+ {
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::complete_liveness);
+
+ // 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.
+ ShenandoahCompleteLivenessClosure cl;
+ parallel_heap_region_iterate(&cl);
+ }
+
+ {
+ ShenandoahGCPhase prepare_evac(ShenandoahPhaseTimings::prepare_evac);
+
+ make_parsable(true);
+
+ trash_cset_regions();
+
+ {
+ ShenandoahHeapLocker locker(lock());
+ _collection_set->clear();
+ _free_set->clear();
+
+ heuristics()->choose_collection_set(_collection_set);
+
+ _free_set->rebuild();
+ }
+ }
+
+ // 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);
+
+ evacuate_and_update_roots();
+
+ if (ShenandoahPacing) {
+ pacer()->setup_for_evac();
+ }
+ } else {
+ if (ShenandoahVerify) {
+ verifier()->verify_after_concmark();
+ }
+
+ if (VerifyAfterGC) {
+ Universe::verify();
+ }
+ }
+
+ } else {
+ concurrent_mark()->cancel();
+ stop_concurrent_marking();
+
+ 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_final_evac() {
+ assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "Should be at safepoint");
+
+ set_evacuation_in_progress(false);
+
+ retire_and_reset_gclabs();
+
+ if (ShenandoahVerify) {
+ verifier()->verify_after_evacuation();
+ }
+
+ if (VerifyAfterGC) {
+ Universe::verify();
+ }
+}
+
+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() {
+ free_set()->recycle_trash();
+}
+
+void ShenandoahHeap::op_reset() {
+ reset_mark_bitmap();
+}
+
+void ShenandoahHeap::op_preclean() {
+ concurrent_mark()->preclean_weak_refs();
+}
+
+void ShenandoahHeap::op_init_traversal() {
+ traversal_gc()->init_traversal_collection();
+}
+
+void ShenandoahHeap::op_traversal() {
+ traversal_gc()->concurrent_traversal_collection();
+}
+
+void ShenandoahHeap::op_final_traversal() {
+ traversal_gc()->final_traversal_collection();
+}
+
+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();
+ metrics.print();
+
+ if (metrics.is_good_progress("Full GC")) {
+ _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) {
+ case _degenerated_traversal:
+ {
+ // Drop the collection set. Note: this leaves some already forwarded objects
+ // behind, which may be problematic, see comments for ShenandoahEvacAssist
+ // workarounds in ShenandoahTraversalHeuristics.
+
+ ShenandoahHeapLocker locker(lock());
+ collection_set()->clear_current_index();
+ for (size_t i = 0; i < collection_set()->count(); i++) {
+ ShenandoahHeapRegion* r = collection_set()->next();
+ r->make_regular_bypass();
+ }
+ collection_set()->clear();
+ }
+ op_final_traversal();
+ op_cleanup();
+ return;
+
+ // 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());
+
+ if (heuristics()->can_do_traversal_gc()) {
+ // Not possible to degenerate from here, upgrade to Full GC right away.
+ cancel_gc(GCCause::_shenandoah_upgrade_to_full_gc);
+ op_degenerated_fail();
+ return;
+ }
+
+ 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;
+ }
+
+ op_cleanup();
+
+ 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.
+ 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();
+ break;
+
+ default:
+ ShouldNotReachHere();
+ }
+
+ if (ShenandoahVerify) {
+ verifier()->verify_after_degenerated();
+ }
+
+ if (VerifyAfterGC) {
+ Universe::verify();
+ }
+
+ metrics.snap_after();
+ metrics.print();
+
+ // 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("Degenerated GC")) {
+ _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::stop_concurrent_marking() {
+ assert(is_concurrent_mark_in_progress(), "How else could we get here?");
+ if (!cancelled_gc()) {
+ // If we needed to update refs, and concurrent marking has been cancelled,
+ // we need to finish updating references.
+ set_has_forwarded_objects(false);
+ mark_complete_marking_context();
+ }
+ set_concurrent_mark_in_progress(false);
+}
+
+void ShenandoahHeap::force_satb_flush_all_threads() {
+ if (!is_concurrent_mark_in_progress() && !is_concurrent_traversal_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) {
+ set_gc_state_mask(MARKING, in_progress);
+ ShenandoahBarrierSet::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress);
+}
+
+void ShenandoahHeap::set_concurrent_traversal_in_progress(bool in_progress) {
+ set_gc_state_mask(TRAVERSAL | HAS_FORWARDED, 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);
+}
+
+HeapWord* ShenandoahHeap::tlab_post_allocation_setup(HeapWord* obj) {
+ // Initialize Brooks pointer for the next object
+ HeapWord* result = obj + ShenandoahBrooksPointer::word_size();
+ ShenandoahBrooksPointer::initialize(oop(result));
+ return result;
+}
+
+ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() :
+ _mark_context(ShenandoahHeap::heap()->marking_context()) {
+}
+
+ShenandoahIsAliveClosure::ShenandoahIsAliveClosure() :
+ _mark_context(ShenandoahHeap::heap()->marking_context()) {
+}
+
+bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) {
+ if (CompressedOops::is_null(obj)) {
+ return false;
+ }
+ obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
+ shenandoah_assert_not_forwarded_if(NULL, obj, ShenandoahHeap::heap()->is_concurrent_mark_in_progress() || ShenandoahHeap::heap()->is_concurrent_traversal_in_progress());
+ return _mark_context->is_marked(obj);
+}
+
+bool ShenandoahIsAliveClosure::do_object_b(oop obj) {
+ if (CompressedOops::is_null(obj)) {
+ return false;
+ }
+ shenandoah_assert_not_forwarded(NULL, obj);
+ return _mark_context->is_marked(obj);
+}
+
+void ShenandoahHeap::ref_processing_init() {
+ assert(_max_workers > 0, "Sanity");
+
+ _ref_processor =
+ new ReferenceProcessor(&_subject_to_discovery, // is_subject_to_discovery
+ ParallelRefProcEnabled, // MT processing
+ _max_workers, // Degree of MT processing
+ true, // 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();
+}
+
+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::unload_classes_and_cleanup_tables(bool full_gc) {
+ assert(heuristics()->can_unload_classes(), "Class unloading should be enabled");
+
+ ShenandoahGCPhase root_phase(full_gc ?
+ ShenandoahPhaseTimings::full_gc_purge :
+ ShenandoahPhaseTimings::purge);
+
+ ShenandoahIsAliveSelector alive;
+ BoolObjectClosure* is_alive = alive.is_alive_closure();
+
+ bool purged_class;
+
+ // Unload classes and purge SystemDictionary.
+ {
+ ShenandoahGCPhase phase(full_gc ?
+ ShenandoahPhaseTimings::full_gc_purge_class_unload :
+ ShenandoahPhaseTimings::purge_class_unload);
+ purged_class = SystemDictionary::do_unloading(gc_timer());
+ }
+
+ {
+ ShenandoahGCPhase phase(full_gc ?
+ ShenandoahPhaseTimings::full_gc_purge_par :
+ ShenandoahPhaseTimings::purge_par);
+ uint active = _workers->active_workers();
+ StringDedupUnlinkOrOopsDoClosure dedup_cl(is_alive, NULL);
+ ParallelCleaningTask unlink_task(is_alive, &dedup_cl, active, purged_class);
+ _workers->run_task(&unlink_task);
+ }
+
+ if (ShenandoahStringDedup::is_enabled()) {
+ ShenandoahGCPhase phase(full_gc ?
+ ShenandoahPhaseTimings::full_gc_purge_string_dedup :
+ ShenandoahPhaseTimings::purge_string_dedup);
+ ShenandoahStringDedup::parallel_cleanup();
+ }
+
+ {
+ ShenandoahGCPhase phase(full_gc ?
+ ShenandoahPhaseTimings::full_gc_purge_cldg :
+ ShenandoahPhaseTimings::purge_cldg);
+ ClassLoaderDataGraph::purge();
+ }
+}
+
+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 OrderAccess::load_acquire(&_bytes_allocated_since_gc_start);
+}
+
+void ShenandoahHeap::reset_bytes_allocated_since_gc_start() {
+ OrderAccess::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::add_nmethod(nm);
+}
+
+void ShenandoahHeap::unregister_nmethod(nmethod* nm) {
+ ShenandoahCodeRoots::remove_nmethod(nm);
+}
+
+oop ShenandoahHeap::pin_object(JavaThread* thr, oop o) {
+ o = ShenandoahBarrierSet::barrier_set()->write_barrier(o);
+ ShenandoahHeapLocker locker(lock());
+ heap_region_containing(o)->make_pinned();
+ return o;
+}
+
+void ShenandoahHeap::unpin_object(JavaThread* thr, oop o) {
+ o = ShenandoahBarrierSet::barrier_set()->read_barrier(o);
+ ShenandoahHeapLocker locker(lock());
+ heap_region_containing(o)->make_unpinned();
+}
+
+GCTimer* ShenandoahHeap::gc_timer() const {
+ return _gc_timer;
+}
+
+#ifdef ASSERT
+void ShenandoahHeap::assert_gc_workers(uint nworkers) {
+ assert(nworkers > 0 && nworkers <= max_workers(), "Sanity");
+
+ if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
+ if (UseDynamicNumberOfGCThreads ||
+ (FLAG_IS_DEFAULT(ParallelGCThreads) && ForceDynamicNumberOfGCThreads)) {
+ assert(nworkers <= ParallelGCThreads, "Cannot use more than it has");
+ } else {
+ // Use ParallelGCThreads inside safepoints
+ assert(nworkers == ParallelGCThreads, "Use ParalleGCThreads within safepoints");
+ }
+ } else {
+ if (UseDynamicNumberOfGCThreads ||
+ (FLAG_IS_DEFAULT(ConcGCThreads) && ForceDynamicNumberOfGCThreads)) {
+ 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* top_at_start_ur = r->concurrent_iteration_safe_limit();
+ assert (top_at_start_ur >= r->bottom(), "sanity");
+ if (r->is_active() && !r->is_cset()) {
+ _heap->marked_object_oop_iterate(r, &cl, top_at_start_ur);
+ }
+ if (ShenandoahPacing) {
+ _heap->pacer()->report_updaterefs(pointer_delta(top_at_start_ur, 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);
+
+ retire_and_reset_gclabs();
+
+ if (ShenandoahVerify) {
+ verifier()->verify_before_updaterefs();
+ }
+
+ set_update_refs_in_progress(true);
+ make_parsable(true);
+ for (uint i = 0; i < num_regions(); i++) {
+ ShenandoahHeapRegion* r = get_region(i);
+ r->set_concurrent_iteration_safe_limit(r->top());
+ }
+
+ // Reset iterator.
+ _update_refs_iterator.reset();
+
+ if (ShenandoahPacing) {
+ pacer()->setup_for_updaterefs();
+ }
+}
+
+void ShenandoahHeap::op_final_updaterefs() {
+ assert(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "must be at safepoint");
+
+ // Check if there is left-over work, and finish it
+ if (_update_refs_iterator.has_next()) {
+ ShenandoahGCPhase final_work(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");
+
+ concurrent_mark()->update_roots(is_degenerated_gc_in_progress() ?
+ ShenandoahPhaseTimings::degen_gc_update_roots:
+ ShenandoahPhaseTimings::final_update_refs_roots);
+
+ ShenandoahGCPhase final_update_refs(ShenandoahPhaseTimings::final_update_refs_recycle);
+
+ trash_cset_regions();
+ set_has_forwarded_objects(false);
+ set_update_refs_in_progress(false);
+
+ if (ShenandoahVerify) {
+ verifier()->verify_after_updaterefs();
+ }
+
+ if (VerifyAfterGC) {
+ Universe::verify();
+ }
+
+ {
+ ShenandoahHeapLocker locker(lock());
+ _free_set->rebuild();
+ }
+}
+
+#ifdef ASSERT
+void ShenandoahHeap::assert_heaplock_owned_by_current_thread() {
+ _lock.assert_owned_by_current_thread();
+}
+
+void ShenandoahHeap::assert_heaplock_not_owned_by_current_thread() {
+ _lock.assert_not_owned_by_current_thread();
+}
+
+void ShenandoahHeap::assert_heaplock_or_safepoint() {
+ _lock.assert_owned_by_current_thread_or_safepoint();
+}
+#endif
+
+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->region_number() / _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->region_number()) continue;
+ if (get_region(g)->is_committed()) {
+ return true;
+ }
+ }
+ return false;
+}
+
+bool ShenandoahHeap::commit_bitmap_slice(ShenandoahHeapRegion* r) {
+ assert_heaplock_owned_by_current_thread();
+
+ 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->region_number() / _bitmap_regions_per_slice;
+ size_t off = _bitmap_bytes_per_slice * slice;
+ size_t len = _bitmap_bytes_per_slice;
+ if (!os::commit_memory((char*)_bitmap_region.start() + off, len, false)) {
+ return false;
+ }
+ return true;
+}
+
+bool ShenandoahHeap::uncommit_bitmap_slice(ShenandoahHeapRegion *r) {
+ assert_heaplock_owned_by_current_thread();
+
+ 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->region_number() / _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());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(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());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(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_final_evac() {
+ TraceCollectorStats tcs(monitoring_support()->stw_collection_counters());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_evac_gross);
+
+ VM_ShenandoahFinalEvac op;
+ VMThread::execute(&op); // jump to entry_final_evac under safepoint
+}
+
+void ShenandoahHeap::vmop_entry_init_updaterefs() {
+ TraceCollectorStats tcs(monitoring_support()->stw_collection_counters());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(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());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs_gross);
+
+ try_inject_alloc_failure();
+ VM_ShenandoahFinalUpdateRefs op;
+ VMThread::execute(&op);
+}
+
+void ShenandoahHeap::vmop_entry_init_traversal() {
+ TraceCollectorStats tcs(monitoring_support()->stw_collection_counters());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_traversal_gc_gross);
+
+ try_inject_alloc_failure();
+ VM_ShenandoahInitTraversalGC op;
+ VMThread::execute(&op);
+}
+
+void ShenandoahHeap::vmop_entry_final_traversal() {
+ TraceCollectorStats tcs(monitoring_support()->stw_collection_counters());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_traversal_gc_gross);
+
+ try_inject_alloc_failure();
+ VM_ShenandoahFinalTraversalGC op;
+ VMThread::execute(&op);
+}
+
+void ShenandoahHeap::vmop_entry_full(GCCause::Cause cause) {
+ TraceCollectorStats tcs(monitoring_support()->full_stw_collection_counters());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(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());
+ ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::degen_gc_gross);
+
+ VM_ShenandoahDegeneratedGC degenerated_gc((int)point);
+ VMThread::execute(°enerated_gc);
+}
+
+void ShenandoahHeap::entry_init_mark() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_mark);
+ const char* msg = init_mark_event_message();
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_init_marking(),
+ "init marking");
+
+ op_init_mark();
+}
+
+void ShenandoahHeap::entry_final_mark() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_mark);
+ const char* msg = final_mark_event_message();
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_final_marking(),
+ "final marking");
+
+ op_final_mark();
+}
+
+void ShenandoahHeap::entry_final_evac() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_evac);
+ static const char* msg = "Pause Final Evac";
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ op_final_evac();
+}
+
+void ShenandoahHeap::entry_init_updaterefs() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_update_refs);
+
+ static const char* msg = "Pause Init Update Refs";
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ // No workers used in this phase, no setup required
+
+ op_init_updaterefs();
+}
+
+void ShenandoahHeap::entry_final_updaterefs() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_update_refs);
+
+ static const char* msg = "Pause Final Update Refs";
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_final_update_ref(),
+ "final reference update");
+
+ op_final_updaterefs();
+}
+
+void ShenandoahHeap::entry_init_traversal() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_traversal_gc);
+
+ static const char* msg = "Pause Init Traversal";
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_stw_traversal(),
+ "init traversal");
+
+ op_init_traversal();
+}
+
+void ShenandoahHeap::entry_final_traversal() {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_traversal_gc);
+
+ static const char* msg = "Pause Final Traversal";
+ GCTraceTime(Info, gc) time(msg, gc_timer());
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_stw_traversal(),
+ "final traversal");
+
+ op_final_traversal();
+}
+
+void ShenandoahHeap::entry_full(GCCause::Cause cause) {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::full_gc);
+
+ static const char* msg = "Pause Full";
+ GCTraceTime(Info, gc) time(msg, gc_timer(), cause, true);
+ EventMark em("%s", msg);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_fullgc(),
+ "full gc");
+
+ op_full(cause);
+}
+
+void ShenandoahHeap::entry_degenerated(int point) {
+ ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::degen_gc);
+
+ ShenandoahDegenPoint dpoint = (ShenandoahDegenPoint)point;
+ const char* msg = degen_event_message(dpoint);
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ 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();
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ 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() {
+ ShenandoahGCPhase conc_evac_phase(ShenandoahPhaseTimings::conc_evac);
+ TraceCollectorStats tcs(monitoring_support()->concurrent_collection_counters());
+
+ static const char* msg = "Concurrent evacuation";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ 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() {
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_update_refs);
+
+ static const char* msg = "Concurrent update references";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ 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_cleanup() {
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_cleanup);
+
+ static const char* msg = "Concurrent cleanup";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ EventMark em("%s", msg);
+
+ // This phase does not use workers, no need for setup
+
+ try_inject_alloc_failure();
+ op_cleanup();
+}
+
+void ShenandoahHeap::entry_reset() {
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_reset);
+
+ static const char* msg = "Concurrent reset";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ 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";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ EventMark em("%s", msg);
+
+ ShenandoahGCPhase conc_preclean(ShenandoahPhaseTimings::conc_preclean);
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_conc_preclean(),
+ "concurrent preclean",
+ /* check_workers = */ false);
+
+ try_inject_alloc_failure();
+ op_preclean();
+ }
+}
+
+void ShenandoahHeap::entry_traversal() {
+ static const char* msg = "Concurrent traversal";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ EventMark em("%s", msg);
+
+ TraceCollectorStats tcs(monitoring_support()->concurrent_collection_counters());
+
+ ShenandoahWorkerScope scope(workers(),
+ ShenandoahWorkerPolicy::calc_workers_for_conc_traversal(),
+ "concurrent traversal");
+
+ try_inject_alloc_failure();
+ op_traversal();
+}
+
+void ShenandoahHeap::entry_uncommit(double shrink_before) {
+ static const char *msg = "Concurrent uncommit";
+ GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
+ EventMark em("%s", msg);
+
+ ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_uncommit);
+
+ 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;
+}
+
+void ShenandoahHeap::enter_evacuation() {
+ _oom_evac_handler.enter_evacuation();
+}
+
+void ShenandoahHeap::leave_evacuation() {
+ _oom_evac_handler.leave_evacuation();
+}
+
+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 {
+ bool update_refs = has_forwarded_objects();
+ bool proc_refs = process_references();
+ bool unload_cls = unload_classes();
+
+ if (update_refs && proc_refs && unload_cls) {
+ return "Pause Init Mark (update refs) (process weakrefs) (unload classes)";
+ } else if (update_refs && proc_refs) {
+ return "Pause Init Mark (update refs) (process weakrefs)";
+ } else if (update_refs && unload_cls) {
+ return "Pause Init Mark (update refs) (unload classes)";
+ } else if (proc_refs && unload_cls) {
+ return "Pause Init Mark (process weakrefs) (unload classes)";
+ } else if (update_refs) {
+ return "Pause Init Mark (update refs)";
+ } 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 {
+ bool update_refs = has_forwarded_objects();
+ bool proc_refs = process_references();
+ bool unload_cls = unload_classes();
+
+ if (update_refs && proc_refs && unload_cls) {
+ return "Pause Final Mark (update refs) (process weakrefs) (unload classes)";
+ } else if (update_refs && proc_refs) {
+ return "Pause Final Mark (update refs) (process weakrefs)";
+ } else if (update_refs && unload_cls) {
+ return "Pause Final Mark (update refs) (unload classes)";
+ } else if (proc_refs && unload_cls) {
+ return "Pause Final Mark (process weakrefs) (unload classes)";
+ } else if (update_refs) {
+ return "Pause Final Mark (update refs)";
+ } 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 {
+ bool update_refs = has_forwarded_objects();
+ bool proc_refs = process_references();
+ bool unload_cls = unload_classes();
+
+ if (update_refs && proc_refs && unload_cls) {
+ return "Concurrent marking (update refs) (process weakrefs) (unload classes)";
+ } else if (update_refs && proc_refs) {
+ return "Concurrent marking (update refs) (process weakrefs)";
+ } else if (update_refs && unload_cls) {
+ return "Concurrent marking (update refs) (unload classes)";
+ } else if (proc_refs && unload_cls) {
+ return "Concurrent marking (process weakrefs) (unload classes)";
+ } else if (update_refs) {
+ return "Concurrent marking (update refs)";
+ } 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_traversal:
+ return "Pause Degenerated GC (Traversal)";
+ 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";
+ }
+}
+
+jushort* ShenandoahHeap::get_liveness_cache(uint worker_id) {
+#ifdef ASSERT
+ 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");
+ jushort* ld = _liveness_cache[worker_id];
+ for (uint i = 0; i < num_regions(); i++) {
+ ShenandoahHeapRegion* r = get_region(i);
+ jushort live = ld[i];
+ if (live > 0) {
+ r->increase_live_data_gc_words(live);
+ ld[i] = 0;
+ }
+ }
+}
+
+size_t ShenandoahHeap::obj_size(oop obj) const {
+ return CollectedHeap::obj_size(obj) + ShenandoahBrooksPointer::word_size();
+}
+
+ptrdiff_t ShenandoahHeap::cell_header_size() const {
+ return ShenandoahBrooksPointer::byte_size();
+}
+
+BoolObjectClosure* ShenandoahIsAliveSelector::is_alive_closure() {
+ return ShenandoahHeap::heap()->has_forwarded_objects() ? reinterpret_cast<BoolObjectClosure*>(&_fwd_alive_cl)
+ : reinterpret_cast<BoolObjectClosure*>(&_alive_cl);
+}