| /* |
| * Copyright (c) 2015, 2017, 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 "aot/aotLoader.hpp" |
| #include "classfile/stringTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "code/codeCache.hpp" |
| #include "gc/g1/bufferingOopClosure.hpp" |
| #include "gc/g1/g1CodeBlobClosure.hpp" |
| #include "gc/g1/g1CollectedHeap.inline.hpp" |
| #include "gc/g1/g1CollectorState.hpp" |
| #include "gc/g1/g1GCPhaseTimes.hpp" |
| #include "gc/g1/g1Policy.hpp" |
| #include "gc/g1/g1RootClosures.hpp" |
| #include "gc/g1/g1RootProcessor.hpp" |
| #include "gc/g1/heapRegion.inline.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "runtime/mutex.hpp" |
| #include "services/management.hpp" |
| #include "utilities/macros.hpp" |
| |
| void G1RootProcessor::worker_has_discovered_all_strong_classes() { |
| assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading"); |
| |
| uint new_value = (uint)Atomic::add(1, &_n_workers_discovered_strong_classes); |
| if (new_value == n_workers()) { |
| // This thread is last. Notify the others. |
| MonitorLockerEx ml(&_lock, Mutex::_no_safepoint_check_flag); |
| _lock.notify_all(); |
| } |
| } |
| |
| void G1RootProcessor::wait_until_all_strong_classes_discovered() { |
| assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading"); |
| |
| if ((uint)_n_workers_discovered_strong_classes != n_workers()) { |
| MonitorLockerEx ml(&_lock, Mutex::_no_safepoint_check_flag); |
| while ((uint)_n_workers_discovered_strong_classes != n_workers()) { |
| _lock.wait(Mutex::_no_safepoint_check_flag, 0, false); |
| } |
| } |
| } |
| |
| G1RootProcessor::G1RootProcessor(G1CollectedHeap* g1h, uint n_workers) : |
| _g1h(g1h), |
| _process_strong_tasks(G1RP_PS_NumElements), |
| _srs(n_workers), |
| _lock(Mutex::leaf, "G1 Root Scanning barrier lock", false, Monitor::_safepoint_check_never), |
| _n_workers_discovered_strong_classes(0) {} |
| |
| void G1RootProcessor::evacuate_roots(G1EvacuationRootClosures* closures, uint worker_i) { |
| double ext_roots_start = os::elapsedTime(); |
| G1GCPhaseTimes* phase_times = _g1h->g1_policy()->phase_times(); |
| |
| process_java_roots(closures, phase_times, worker_i); |
| |
| // This is the point where this worker thread will not find more strong CLDs/nmethods. |
| // Report this so G1 can synchronize the strong and weak CLDs/nmethods processing. |
| if (closures->trace_metadata()) { |
| worker_has_discovered_all_strong_classes(); |
| } |
| |
| process_vm_roots(closures, phase_times, worker_i); |
| process_string_table_roots(closures, phase_times, worker_i); |
| |
| { |
| // Now the CM ref_processor roots. |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CMRefRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_refProcessor_oops_do)) { |
| // We need to treat the discovered reference lists of the |
| // concurrent mark ref processor as roots and keep entries |
| // (which are added by the marking threads) on them live |
| // until they can be processed at the end of marking. |
| _g1h->ref_processor_cm()->weak_oops_do(closures->strong_oops()); |
| } |
| } |
| |
| if (closures->trace_metadata()) { |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::WaitForStrongCLD, worker_i); |
| // Barrier to make sure all workers passed |
| // the strong CLD and strong nmethods phases. |
| wait_until_all_strong_classes_discovered(); |
| } |
| |
| // Now take the complement of the strong CLDs. |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::WeakCLDRoots, worker_i); |
| assert(closures->second_pass_weak_clds() != NULL, "Should be non-null if we are tracing metadata."); |
| ClassLoaderDataGraph::roots_cld_do(NULL, closures->second_pass_weak_clds()); |
| } else { |
| phase_times->record_time_secs(G1GCPhaseTimes::WaitForStrongCLD, worker_i, 0.0); |
| phase_times->record_time_secs(G1GCPhaseTimes::WeakCLDRoots, worker_i, 0.0); |
| assert(closures->second_pass_weak_clds() == NULL, "Should be null if not tracing metadata."); |
| } |
| |
| // Finish up any enqueued closure apps (attributed as object copy time). |
| closures->flush(); |
| |
| double obj_copy_time_sec = closures->closure_app_seconds(); |
| |
| phase_times->record_time_secs(G1GCPhaseTimes::ObjCopy, worker_i, obj_copy_time_sec); |
| |
| double ext_root_time_sec = os::elapsedTime() - ext_roots_start - obj_copy_time_sec; |
| |
| phase_times->record_time_secs(G1GCPhaseTimes::ExtRootScan, worker_i, ext_root_time_sec); |
| |
| // During conc marking we have to filter the per-thread SATB buffers |
| // to make sure we remove any oops into the CSet (which will show up |
| // as implicitly live). |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::SATBFiltering, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_filter_satb_buffers) && _g1h->collector_state()->mark_in_progress()) { |
| JavaThread::satb_mark_queue_set().filter_thread_buffers(); |
| } |
| } |
| |
| _process_strong_tasks.all_tasks_completed(n_workers()); |
| } |
| |
| // Adaptor to pass the closures to the strong roots in the VM. |
| class StrongRootsClosures : public G1RootClosures { |
| OopClosure* _roots; |
| CLDClosure* _clds; |
| CodeBlobClosure* _blobs; |
| public: |
| StrongRootsClosures(OopClosure* roots, CLDClosure* clds, CodeBlobClosure* blobs) : |
| _roots(roots), _clds(clds), _blobs(blobs) {} |
| |
| OopClosure* weak_oops() { return NULL; } |
| OopClosure* strong_oops() { return _roots; } |
| |
| CLDClosure* weak_clds() { return NULL; } |
| CLDClosure* strong_clds() { return _clds; } |
| |
| CodeBlobClosure* strong_codeblobs() { return _blobs; } |
| }; |
| |
| void G1RootProcessor::process_strong_roots(OopClosure* oops, |
| CLDClosure* clds, |
| CodeBlobClosure* blobs) { |
| StrongRootsClosures closures(oops, clds, blobs); |
| |
| process_java_roots(&closures, NULL, 0); |
| process_vm_roots(&closures, NULL, 0); |
| |
| _process_strong_tasks.all_tasks_completed(n_workers()); |
| } |
| |
| // Adaptor to pass the closures to all the roots in the VM. |
| class AllRootsClosures : public G1RootClosures { |
| OopClosure* _roots; |
| CLDClosure* _clds; |
| public: |
| AllRootsClosures(OopClosure* roots, CLDClosure* clds) : |
| _roots(roots), _clds(clds) {} |
| |
| OopClosure* weak_oops() { return _roots; } |
| OopClosure* strong_oops() { return _roots; } |
| |
| // By returning the same CLDClosure for both weak and strong CLDs we ensure |
| // that a single walk of the CLDG will invoke the closure on all CLDs i the |
| // system. |
| CLDClosure* weak_clds() { return _clds; } |
| CLDClosure* strong_clds() { return _clds; } |
| |
| // We don't want to visit code blobs more than once, so we return NULL for the |
| // strong case and walk the entire code cache as a separate step. |
| CodeBlobClosure* strong_codeblobs() { return NULL; } |
| }; |
| |
| void G1RootProcessor::process_all_roots(OopClosure* oops, |
| CLDClosure* clds, |
| CodeBlobClosure* blobs, |
| bool process_string_table) { |
| AllRootsClosures closures(oops, clds); |
| |
| process_java_roots(&closures, NULL, 0); |
| process_vm_roots(&closures, NULL, 0); |
| |
| if (process_string_table) { |
| process_string_table_roots(&closures, NULL, 0); |
| } |
| process_code_cache_roots(blobs, NULL, 0); |
| |
| _process_strong_tasks.all_tasks_completed(n_workers()); |
| } |
| |
| void G1RootProcessor::process_all_roots(OopClosure* oops, |
| CLDClosure* clds, |
| CodeBlobClosure* blobs) { |
| process_all_roots(oops, clds, blobs, true); |
| } |
| |
| void G1RootProcessor::process_all_roots_no_string_table(OopClosure* oops, |
| CLDClosure* clds, |
| CodeBlobClosure* blobs) { |
| assert(!ClassUnloading, "Should only be used when class unloading is disabled"); |
| process_all_roots(oops, clds, blobs, false); |
| } |
| |
| void G1RootProcessor::process_java_roots(G1RootClosures* closures, |
| G1GCPhaseTimes* phase_times, |
| uint worker_i) { |
| // Iterating over the CLDG and the Threads are done early to allow us to |
| // first process the strong CLDs and nmethods and then, after a barrier, |
| // let the thread process the weak CLDs and nmethods. |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CLDGRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_ClassLoaderDataGraph_oops_do)) { |
| ClassLoaderDataGraph::roots_cld_do(closures->strong_clds(), closures->weak_clds()); |
| } |
| } |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ThreadRoots, worker_i); |
| bool is_par = n_workers() > 1; |
| Threads::possibly_parallel_oops_do(is_par, |
| closures->strong_oops(), |
| closures->strong_codeblobs()); |
| } |
| } |
| |
| void G1RootProcessor::process_vm_roots(G1RootClosures* closures, |
| G1GCPhaseTimes* phase_times, |
| uint worker_i) { |
| OopClosure* strong_roots = closures->strong_oops(); |
| OopClosure* weak_roots = closures->weak_oops(); |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::UniverseRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_Universe_oops_do)) { |
| Universe::oops_do(strong_roots); |
| } |
| } |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JNIRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_JNIHandles_oops_do)) { |
| JNIHandles::oops_do(strong_roots); |
| } |
| } |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ObjectSynchronizerRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_ObjectSynchronizer_oops_do)) { |
| ObjectSynchronizer::oops_do(strong_roots); |
| } |
| } |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ManagementRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_Management_oops_do)) { |
| Management::oops_do(strong_roots); |
| } |
| } |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JVMTIRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_jvmti_oops_do)) { |
| JvmtiExport::oops_do(strong_roots); |
| } |
| } |
| |
| #if INCLUDE_AOT |
| if (UseAOT) { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::AOTCodeRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_aot_oops_do)) { |
| AOTLoader::oops_do(strong_roots); |
| } |
| } |
| #endif |
| |
| { |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::SystemDictionaryRoots, worker_i); |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_SystemDictionary_oops_do)) { |
| SystemDictionary::roots_oops_do(strong_roots, weak_roots); |
| } |
| } |
| } |
| |
| void G1RootProcessor::process_string_table_roots(G1RootClosures* closures, |
| G1GCPhaseTimes* phase_times, |
| uint worker_i) { |
| assert(closures->weak_oops() != NULL, "Should only be called when all roots are processed"); |
| G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::StringTableRoots, worker_i); |
| // All threads execute the following. A specific chunk of buckets |
| // from the StringTable are the individual tasks. |
| StringTable::possibly_parallel_oops_do(closures->weak_oops()); |
| } |
| |
| void G1RootProcessor::process_code_cache_roots(CodeBlobClosure* code_closure, |
| G1GCPhaseTimes* phase_times, |
| uint worker_i) { |
| if (!_process_strong_tasks.is_task_claimed(G1RP_PS_CodeCache_oops_do)) { |
| CodeCache::blobs_do(code_closure); |
| } |
| } |
| |
| uint G1RootProcessor::n_workers() const { |
| return _srs.n_threads(); |
| } |