| /* |
| * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "gc/shared/allocTracer.hpp" |
| #include "gc/shared/barrierSet.hpp" |
| #include "gc/shared/collectedHeap.hpp" |
| #include "gc/shared/collectedHeap.inline.hpp" |
| #include "gc/shared/gcLocker.inline.hpp" |
| #include "gc/shared/gcHeapSummary.hpp" |
| #include "gc/shared/gcTrace.hpp" |
| #include "gc/shared/gcTraceTime.inline.hpp" |
| #include "gc/shared/gcVMOperations.hpp" |
| #include "gc/shared/gcWhen.hpp" |
| #include "gc/shared/memAllocator.hpp" |
| #include "logging/log.hpp" |
| #include "memory/metaspace.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "memory/universe.hpp" |
| #include "oops/instanceMirrorKlass.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/init.hpp" |
| #include "runtime/thread.inline.hpp" |
| #include "runtime/threadSMR.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "services/heapDumper.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/copy.hpp" |
| |
| class ClassLoaderData; |
| |
| size_t CollectedHeap::_filler_array_max_size = 0; |
| |
| template <> |
| void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) { |
| st->print_cr("GC heap %s", m.is_before ? "before" : "after"); |
| st->print_raw(m); |
| } |
| |
| void GCHeapLog::log_heap(CollectedHeap* heap, bool before) { |
| if (!should_log()) { |
| return; |
| } |
| |
| double timestamp = fetch_timestamp(); |
| MutexLocker ml(&_mutex, Mutex::_no_safepoint_check_flag); |
| int index = compute_log_index(); |
| _records[index].thread = NULL; // Its the GC thread so it's not that interesting. |
| _records[index].timestamp = timestamp; |
| _records[index].data.is_before = before; |
| stringStream st(_records[index].data.buffer(), _records[index].data.size()); |
| |
| st.print_cr("{Heap %s GC invocations=%u (full %u):", |
| before ? "before" : "after", |
| heap->total_collections(), |
| heap->total_full_collections()); |
| |
| heap->print_on(&st); |
| st.print_cr("}"); |
| } |
| |
| size_t CollectedHeap::unused() const { |
| MutexLocker ml(Heap_lock); |
| return capacity() - used(); |
| } |
| |
| VirtualSpaceSummary CollectedHeap::create_heap_space_summary() { |
| size_t capacity_in_words = capacity() / HeapWordSize; |
| |
| return VirtualSpaceSummary( |
| _reserved.start(), _reserved.start() + capacity_in_words, _reserved.end()); |
| } |
| |
| GCHeapSummary CollectedHeap::create_heap_summary() { |
| VirtualSpaceSummary heap_space = create_heap_space_summary(); |
| return GCHeapSummary(heap_space, used()); |
| } |
| |
| MetaspaceSummary CollectedHeap::create_metaspace_summary() { |
| const MetaspaceSizes meta_space( |
| MetaspaceUtils::committed_bytes(), |
| MetaspaceUtils::used_bytes(), |
| MetaspaceUtils::reserved_bytes()); |
| const MetaspaceSizes data_space( |
| MetaspaceUtils::committed_bytes(Metaspace::NonClassType), |
| MetaspaceUtils::used_bytes(Metaspace::NonClassType), |
| MetaspaceUtils::reserved_bytes(Metaspace::NonClassType)); |
| const MetaspaceSizes class_space( |
| MetaspaceUtils::committed_bytes(Metaspace::ClassType), |
| MetaspaceUtils::used_bytes(Metaspace::ClassType), |
| MetaspaceUtils::reserved_bytes(Metaspace::ClassType)); |
| |
| const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary = |
| MetaspaceUtils::chunk_free_list_summary(Metaspace::NonClassType); |
| const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary = |
| MetaspaceUtils::chunk_free_list_summary(Metaspace::ClassType); |
| |
| return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space, |
| ms_chunk_free_list_summary, class_chunk_free_list_summary); |
| } |
| |
| void CollectedHeap::print_heap_before_gc() { |
| Universe::print_heap_before_gc(); |
| if (_gc_heap_log != NULL) { |
| _gc_heap_log->log_heap_before(this); |
| } |
| } |
| |
| void CollectedHeap::print_heap_after_gc() { |
| Universe::print_heap_after_gc(); |
| if (_gc_heap_log != NULL) { |
| _gc_heap_log->log_heap_after(this); |
| } |
| } |
| |
| void CollectedHeap::print() const { print_on(tty); } |
| |
| void CollectedHeap::print_on_error(outputStream* st) const { |
| st->print_cr("Heap:"); |
| print_extended_on(st); |
| st->cr(); |
| |
| BarrierSet* bs = BarrierSet::barrier_set(); |
| if (bs != NULL) { |
| bs->print_on(st); |
| } |
| } |
| |
| void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) { |
| const GCHeapSummary& heap_summary = create_heap_summary(); |
| gc_tracer->report_gc_heap_summary(when, heap_summary); |
| |
| const MetaspaceSummary& metaspace_summary = create_metaspace_summary(); |
| gc_tracer->report_metaspace_summary(when, metaspace_summary); |
| } |
| |
| void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) { |
| trace_heap(GCWhen::BeforeGC, gc_tracer); |
| } |
| |
| void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) { |
| trace_heap(GCWhen::AfterGC, gc_tracer); |
| } |
| |
| // Default implementation, for collectors that don't support the feature. |
| bool CollectedHeap::supports_concurrent_gc_breakpoints() const { |
| return false; |
| } |
| |
| bool CollectedHeap::is_oop(oop object) const { |
| if (!is_object_aligned(object)) { |
| return false; |
| } |
| |
| if (!is_in(object)) { |
| return false; |
| } |
| |
| if (is_in(object->klass_or_null())) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // Memory state functions. |
| |
| |
| CollectedHeap::CollectedHeap() : |
| _is_gc_active(false), |
| _last_whole_heap_examined_time_ns(os::javaTimeNanos()), |
| _total_collections(0), |
| _total_full_collections(0), |
| _gc_cause(GCCause::_no_gc), |
| _gc_lastcause(GCCause::_no_gc) |
| { |
| const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT)); |
| const size_t elements_per_word = HeapWordSize / sizeof(jint); |
| _filler_array_max_size = align_object_size(filler_array_hdr_size() + |
| max_len / elements_per_word); |
| |
| NOT_PRODUCT(_promotion_failure_alot_count = 0;) |
| NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;) |
| |
| if (UsePerfData) { |
| EXCEPTION_MARK; |
| |
| // create the gc cause jvmstat counters |
| _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause", |
| 80, GCCause::to_string(_gc_cause), CHECK); |
| |
| _perf_gc_lastcause = |
| PerfDataManager::create_string_variable(SUN_GC, "lastCause", |
| 80, GCCause::to_string(_gc_lastcause), CHECK); |
| } |
| |
| // Create the ring log |
| if (LogEvents) { |
| _gc_heap_log = new GCHeapLog(); |
| } else { |
| _gc_heap_log = NULL; |
| } |
| } |
| |
| // This interface assumes that it's being called by the |
| // vm thread. It collects the heap assuming that the |
| // heap lock is already held and that we are executing in |
| // the context of the vm thread. |
| void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { |
| Thread* thread = Thread::current(); |
| assert(thread->is_VM_thread(), "Precondition#1"); |
| assert(Heap_lock->is_locked(), "Precondition#2"); |
| GCCauseSetter gcs(this, cause); |
| switch (cause) { |
| case GCCause::_heap_inspection: |
| case GCCause::_heap_dump: |
| case GCCause::_metadata_GC_threshold : { |
| HandleMark hm(thread); |
| do_full_collection(false); // don't clear all soft refs |
| break; |
| } |
| case GCCause::_archive_time_gc: |
| case GCCause::_metadata_GC_clear_soft_refs: { |
| HandleMark hm(thread); |
| do_full_collection(true); // do clear all soft refs |
| break; |
| } |
| default: |
| ShouldNotReachHere(); // Unexpected use of this function |
| } |
| } |
| |
| MetaWord* CollectedHeap::satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, |
| size_t word_size, |
| Metaspace::MetadataType mdtype) { |
| uint loop_count = 0; |
| uint gc_count = 0; |
| uint full_gc_count = 0; |
| |
| assert(!Heap_lock->owned_by_self(), "Should not be holding the Heap_lock"); |
| |
| do { |
| MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype); |
| if (result != NULL) { |
| return result; |
| } |
| |
| if (GCLocker::is_active_and_needs_gc()) { |
| // If the GCLocker is active, just expand and allocate. |
| // If that does not succeed, wait if this thread is not |
| // in a critical section itself. |
| result = loader_data->metaspace_non_null()->expand_and_allocate(word_size, mdtype); |
| if (result != NULL) { |
| return result; |
| } |
| JavaThread* jthr = JavaThread::current(); |
| if (!jthr->in_critical()) { |
| // Wait for JNI critical section to be exited |
| GCLocker::stall_until_clear(); |
| // The GC invoked by the last thread leaving the critical |
| // section will be a young collection and a full collection |
| // is (currently) needed for unloading classes so continue |
| // to the next iteration to get a full GC. |
| continue; |
| } else { |
| if (CheckJNICalls) { |
| fatal("Possible deadlock due to allocating while" |
| " in jni critical section"); |
| } |
| return NULL; |
| } |
| } |
| |
| { // Need lock to get self consistent gc_count's |
| MutexLocker ml(Heap_lock); |
| gc_count = Universe::heap()->total_collections(); |
| full_gc_count = Universe::heap()->total_full_collections(); |
| } |
| |
| // Generate a VM operation |
| VM_CollectForMetadataAllocation op(loader_data, |
| word_size, |
| mdtype, |
| gc_count, |
| full_gc_count, |
| GCCause::_metadata_GC_threshold); |
| VMThread::execute(&op); |
| |
| // If GC was locked out, try again. Check before checking success because the |
| // prologue could have succeeded and the GC still have been locked out. |
| if (op.gc_locked()) { |
| continue; |
| } |
| |
| if (op.prologue_succeeded()) { |
| return op.result(); |
| } |
| loop_count++; |
| if ((QueuedAllocationWarningCount > 0) && |
| (loop_count % QueuedAllocationWarningCount == 0)) { |
| log_warning(gc, ergo)("satisfy_failed_metadata_allocation() retries %d times," |
| " size=" SIZE_FORMAT, loop_count, word_size); |
| } |
| } while (true); // Until a GC is done |
| } |
| |
| MemoryUsage CollectedHeap::memory_usage() { |
| return MemoryUsage(InitialHeapSize, used(), capacity(), max_capacity()); |
| } |
| |
| |
| #ifndef PRODUCT |
| void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) { |
| if (CheckMemoryInitialization && ZapUnusedHeapArea) { |
| // please note mismatch between size (in 32/64 bit words), and ju_addr that always point to a 32 bit word |
| for (juint* ju_addr = reinterpret_cast<juint*>(addr); ju_addr < reinterpret_cast<juint*>(addr + size); ++ju_addr) { |
| assert(*ju_addr == badHeapWordVal, "Found non badHeapWordValue in pre-allocation check"); |
| } |
| } |
| } |
| #endif // PRODUCT |
| |
| size_t CollectedHeap::max_tlab_size() const { |
| // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE]. |
| // This restriction could be removed by enabling filling with multiple arrays. |
| // If we compute that the reasonable way as |
| // header_size + ((sizeof(jint) * max_jint) / HeapWordSize) |
| // we'll overflow on the multiply, so we do the divide first. |
| // We actually lose a little by dividing first, |
| // but that just makes the TLAB somewhat smaller than the biggest array, |
| // which is fine, since we'll be able to fill that. |
| size_t max_int_size = typeArrayOopDesc::header_size(T_INT) + |
| sizeof(jint) * |
| ((juint) max_jint / (size_t) HeapWordSize); |
| return align_down(max_int_size, MinObjAlignment); |
| } |
| |
| size_t CollectedHeap::filler_array_hdr_size() { |
| return align_object_offset(arrayOopDesc::header_size(T_INT)); // align to Long |
| } |
| |
| size_t CollectedHeap::filler_array_min_size() { |
| return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment |
| } |
| |
| #ifdef ASSERT |
| void CollectedHeap::fill_args_check(HeapWord* start, size_t words) |
| { |
| assert(words >= min_fill_size(), "too small to fill"); |
| assert(is_object_aligned(words), "unaligned size"); |
| } |
| |
| void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap) |
| { |
| if (ZapFillerObjects && zap) { |
| Copy::fill_to_words(start + filler_array_hdr_size(), |
| words - filler_array_hdr_size(), 0XDEAFBABE); |
| } |
| } |
| #endif // ASSERT |
| |
| void |
| CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap) |
| { |
| assert(words >= filler_array_min_size(), "too small for an array"); |
| assert(words <= filler_array_max_size(), "too big for a single object"); |
| |
| const size_t payload_size = words - filler_array_hdr_size(); |
| const size_t len = payload_size * HeapWordSize / sizeof(jint); |
| assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len); |
| |
| ObjArrayAllocator allocator(Universe::intArrayKlassObj(), words, (int)len, /* do_zero */ false); |
| allocator.initialize(start); |
| DEBUG_ONLY(zap_filler_array(start, words, zap);) |
| } |
| |
| void |
| CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap) |
| { |
| assert(words <= filler_array_max_size(), "too big for a single object"); |
| |
| if (words >= filler_array_min_size()) { |
| fill_with_array(start, words, zap); |
| } else if (words > 0) { |
| assert(words == min_fill_size(), "unaligned size"); |
| ObjAllocator allocator(SystemDictionary::Object_klass(), words); |
| allocator.initialize(start); |
| } |
| } |
| |
| void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap) |
| { |
| DEBUG_ONLY(fill_args_check(start, words);) |
| HandleMark hm(Thread::current()); // Free handles before leaving. |
| fill_with_object_impl(start, words, zap); |
| } |
| |
| void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap) |
| { |
| DEBUG_ONLY(fill_args_check(start, words);) |
| HandleMark hm(Thread::current()); // Free handles before leaving. |
| |
| // Multiple objects may be required depending on the filler array maximum size. Fill |
| // the range up to that with objects that are filler_array_max_size sized. The |
| // remainder is filled with a single object. |
| const size_t min = min_fill_size(); |
| const size_t max = filler_array_max_size(); |
| while (words > max) { |
| const size_t cur = (words - max) >= min ? max : max - min; |
| fill_with_array(start, cur, zap); |
| start += cur; |
| words -= cur; |
| } |
| |
| fill_with_object_impl(start, words, zap); |
| } |
| |
| void CollectedHeap::fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap) { |
| CollectedHeap::fill_with_object(start, end, zap); |
| } |
| |
| size_t CollectedHeap::min_dummy_object_size() const { |
| return oopDesc::header_size(); |
| } |
| |
| size_t CollectedHeap::tlab_alloc_reserve() const { |
| size_t min_size = min_dummy_object_size(); |
| return min_size > (size_t)MinObjAlignment ? align_object_size(min_size) : 0; |
| } |
| |
| HeapWord* CollectedHeap::allocate_new_tlab(size_t min_size, |
| size_t requested_size, |
| size_t* actual_size) { |
| guarantee(false, "thread-local allocation buffers not supported"); |
| return NULL; |
| } |
| |
| void CollectedHeap::ensure_parsability(bool retire_tlabs) { |
| assert(SafepointSynchronize::is_at_safepoint() || !is_init_completed(), |
| "Should only be called at a safepoint or at start-up"); |
| |
| ThreadLocalAllocStats stats; |
| |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next();) { |
| BarrierSet::barrier_set()->make_parsable(thread); |
| if (UseTLAB) { |
| if (retire_tlabs) { |
| thread->tlab().retire(&stats); |
| } else { |
| thread->tlab().make_parsable(); |
| } |
| } |
| } |
| |
| stats.publish(); |
| } |
| |
| void CollectedHeap::resize_all_tlabs() { |
| assert(SafepointSynchronize::is_at_safepoint() || !is_init_completed(), |
| "Should only resize tlabs at safepoint"); |
| |
| if (UseTLAB && ResizeTLAB) { |
| for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { |
| thread->tlab().resize(); |
| } |
| } |
| } |
| |
| jlong CollectedHeap::millis_since_last_whole_heap_examined() { |
| return (os::javaTimeNanos() - _last_whole_heap_examined_time_ns) / NANOSECS_PER_MILLISEC; |
| } |
| |
| void CollectedHeap::record_whole_heap_examined_timestamp() { |
| _last_whole_heap_examined_time_ns = os::javaTimeNanos(); |
| } |
| |
| void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) { |
| assert(timer != NULL, "timer is null"); |
| if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) { |
| GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer); |
| HeapDumper::dump_heap(); |
| } |
| |
| LogTarget(Trace, gc, classhisto) lt; |
| if (lt.is_enabled()) { |
| GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer); |
| ResourceMark rm; |
| LogStream ls(lt); |
| VM_GC_HeapInspection inspector(&ls, false /* ! full gc */); |
| inspector.doit(); |
| } |
| } |
| |
| void CollectedHeap::pre_full_gc_dump(GCTimer* timer) { |
| full_gc_dump(timer, true); |
| } |
| |
| void CollectedHeap::post_full_gc_dump(GCTimer* timer) { |
| full_gc_dump(timer, false); |
| } |
| |
| void CollectedHeap::initialize_reserved_region(const ReservedHeapSpace& rs) { |
| // It is important to do this in a way such that concurrent readers can't |
| // temporarily think something is in the heap. (Seen this happen in asserts.) |
| _reserved.set_word_size(0); |
| _reserved.set_start((HeapWord*)rs.base()); |
| _reserved.set_end((HeapWord*)rs.end()); |
| } |
| |
| void CollectedHeap::post_initialize() { |
| initialize_serviceability(); |
| } |
| |
| #ifndef PRODUCT |
| |
| bool CollectedHeap::promotion_should_fail(volatile size_t* count) { |
| // Access to count is not atomic; the value does not have to be exact. |
| if (PromotionFailureALot) { |
| const size_t gc_num = total_collections(); |
| const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number; |
| if (elapsed_gcs >= PromotionFailureALotInterval) { |
| // Test for unsigned arithmetic wrap-around. |
| if (++*count >= PromotionFailureALotCount) { |
| *count = 0; |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| bool CollectedHeap::promotion_should_fail() { |
| return promotion_should_fail(&_promotion_failure_alot_count); |
| } |
| |
| void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) { |
| if (PromotionFailureALot) { |
| _promotion_failure_alot_gc_number = total_collections(); |
| *count = 0; |
| } |
| } |
| |
| void CollectedHeap::reset_promotion_should_fail() { |
| reset_promotion_should_fail(&_promotion_failure_alot_count); |
| } |
| |
| #endif // #ifndef PRODUCT |
| |
| bool CollectedHeap::supports_object_pinning() const { |
| return false; |
| } |
| |
| oop CollectedHeap::pin_object(JavaThread* thread, oop obj) { |
| ShouldNotReachHere(); |
| return NULL; |
| } |
| |
| void CollectedHeap::unpin_object(JavaThread* thread, oop obj) { |
| ShouldNotReachHere(); |
| } |
| |
| void CollectedHeap::deduplicate_string(oop str) { |
| // Do nothing, unless overridden in subclass. |
| } |
| |
| uint32_t CollectedHeap::hash_oop(oop obj) const { |
| const uintptr_t addr = cast_from_oop<uintptr_t>(obj); |
| return static_cast<uint32_t>(addr >> LogMinObjAlignment); |
| } |