mgerdin@7659: /*
fmatte@9358:  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
mgerdin@7659:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
mgerdin@7659:  *
mgerdin@7659:  * This code is free software; you can redistribute it and/or modify it
mgerdin@7659:  * under the terms of the GNU General Public License version 2 only, as
mgerdin@7659:  * published by the Free Software Foundation.
mgerdin@7659:  *
mgerdin@7659:  * This code is distributed in the hope that it will be useful, but WITHOUT
mgerdin@7659:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
mgerdin@7659:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
mgerdin@7659:  * version 2 for more details (a copy is included in the LICENSE file that
mgerdin@7659:  * accompanied this code).
mgerdin@7659:  *
mgerdin@7659:  * You should have received a copy of the GNU General Public License version
mgerdin@7659:  * 2 along with this work; if not, write to the Free Software Foundation,
mgerdin@7659:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
mgerdin@7659:  *
mgerdin@7659:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
mgerdin@7659:  * or visit www.oracle.com if you need additional information or have any
mgerdin@7659:  * questions.
mgerdin@7659:  *
mgerdin@7659:  */
mgerdin@7659: 
mgerdin@7659: #include "precompiled.hpp"
mgerdin@7659: 
mgerdin@7659: #include "classfile/symbolTable.hpp"
mgerdin@7659: #include "classfile/systemDictionary.hpp"
mgerdin@7659: #include "code/codeCache.hpp"
mgerdin@7659: #include "gc_implementation/g1/bufferingOopClosure.hpp"
mgerdin@7659: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
mgerdin@7659: #include "gc_implementation/g1/g1CollectorPolicy.hpp"
mgerdin@7659: #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
mgerdin@7659: #include "gc_implementation/g1/g1RemSet.inline.hpp"
mgerdin@7659: #include "gc_implementation/g1/g1RootProcessor.hpp"
mgerdin@7659: #include "memory/allocation.inline.hpp"
mgerdin@7659: #include "runtime/fprofiler.hpp"
mgerdin@7659: #include "runtime/mutex.hpp"
mgerdin@7659: #include "services/management.hpp"
mgerdin@7659: 
mgerdin@7659: class G1CodeBlobClosure : public CodeBlobClosure {
mgerdin@7659:   class HeapRegionGatheringOopClosure : public OopClosure {
mgerdin@7659:     G1CollectedHeap* _g1h;
mgerdin@7659:     OopClosure* _work;
mgerdin@7659:     nmethod* _nm;
mgerdin@7659: 
mgerdin@7659:     template <typename T>
mgerdin@7659:     void do_oop_work(T* p) {
mgerdin@7659:       _work->do_oop(p);
mgerdin@7659:       T oop_or_narrowoop = oopDesc::load_heap_oop(p);
mgerdin@7659:       if (!oopDesc::is_null(oop_or_narrowoop)) {
mgerdin@7659:         oop o = oopDesc::decode_heap_oop_not_null(oop_or_narrowoop);
mgerdin@7659:         HeapRegion* hr = _g1h->heap_region_containing_raw(o);
mgerdin@7659:         assert(!_g1h->obj_in_cs(o) || hr->rem_set()->strong_code_roots_list_contains(_nm), "if o still in CS then evacuation failed and nm must already be in the remset");
mgerdin@7659:         hr->add_strong_code_root(_nm);
mgerdin@7659:       }
mgerdin@7659:     }
mgerdin@7659: 
mgerdin@7659:   public:
mgerdin@7659:     HeapRegionGatheringOopClosure(OopClosure* oc) : _g1h(G1CollectedHeap::heap()), _work(oc), _nm(NULL) {}
mgerdin@7659: 
mgerdin@7659:     void do_oop(oop* o) {
mgerdin@7659:       do_oop_work(o);
mgerdin@7659:     }
mgerdin@7659: 
mgerdin@7659:     void do_oop(narrowOop* o) {
mgerdin@7659:       do_oop_work(o);
mgerdin@7659:     }
mgerdin@7659: 
mgerdin@7659:     void set_nm(nmethod* nm) {
mgerdin@7659:       _nm = nm;
mgerdin@7659:     }
mgerdin@7659:   };
mgerdin@7659: 
mgerdin@7659:   HeapRegionGatheringOopClosure _oc;
mgerdin@7659: public:
mgerdin@7659:   G1CodeBlobClosure(OopClosure* oc) : _oc(oc) {}
mgerdin@7659: 
mgerdin@7659:   void do_code_blob(CodeBlob* cb) {
mgerdin@7659:     nmethod* nm = cb->as_nmethod_or_null();
mgerdin@7659:     if (nm != NULL) {
mgerdin@7659:       if (!nm->test_set_oops_do_mark()) {
mgerdin@7659:         _oc.set_nm(nm);
mgerdin@7659:         nm->oops_do(&_oc);
mgerdin@7659:         nm->fix_oop_relocations();
mgerdin@7659:       }
mgerdin@7659:     }
mgerdin@7659:   }
mgerdin@7659: };
mgerdin@7659: 
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::worker_has_discovered_all_strong_classes() {
mgerdin@7659:   uint n_workers = _g1h->n_par_threads();
mgerdin@7659:   assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading");
mgerdin@7659: 
sangheki@7764:   if (n_workers > 0) {
sangheki@7764:     uint new_value = (uint)Atomic::add(1, &_n_workers_discovered_strong_classes);
sangheki@7764:     if (new_value == n_workers) {
sangheki@7764:       // This thread is last. Notify the others.
sangheki@7764:       MonitorLockerEx ml(&_lock, Mutex::_no_safepoint_check_flag);
sangheki@7764:       _lock.notify_all();
sangheki@7764:     }
mgerdin@7659:   }
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::wait_until_all_strong_classes_discovered() {
mgerdin@7659:   uint n_workers = _g1h->n_par_threads();
mgerdin@7659:   assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading");
mgerdin@7659: 
sangheki@7764:   if (n_workers > 0 && (uint)_n_workers_discovered_strong_classes != n_workers) {
mgerdin@7659:     MonitorLockerEx ml(&_lock, Mutex::_no_safepoint_check_flag);
mgerdin@7659:     while ((uint)_n_workers_discovered_strong_classes != n_workers) {
mgerdin@7659:       _lock.wait(Mutex::_no_safepoint_check_flag, 0, false);
mgerdin@7659:     }
mgerdin@7659:   }
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: G1RootProcessor::G1RootProcessor(G1CollectedHeap* g1h) :
mgerdin@7659:     _g1h(g1h),
mgerdin@8070:     _process_strong_tasks(G1RP_PS_NumElements),
mgerdin@7659:     _srs(g1h),
mgerdin@7659:     _lock(Mutex::leaf, "G1 Root Scanning barrier lock", false),
mgerdin@7659:     _n_workers_discovered_strong_classes(0) {}
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::evacuate_roots(OopClosure* scan_non_heap_roots,
mgerdin@7659:                                      OopClosure* scan_non_heap_weak_roots,
mgerdin@7659:                                      CLDClosure* scan_strong_clds,
mgerdin@7659:                                      CLDClosure* scan_weak_clds,
mgerdin@7659:                                      bool trace_metadata,
mgerdin@7659:                                      uint worker_i) {
mgerdin@7659:   // First scan the shared roots.
mgerdin@7659:   double ext_roots_start = os::elapsedTime();
brutisso@7660:   G1GCPhaseTimes* phase_times = _g1h->g1_policy()->phase_times();
mgerdin@7659: 
mgerdin@7659:   BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots);
mgerdin@7659:   BufferingOopClosure buf_scan_non_heap_weak_roots(scan_non_heap_weak_roots);
mgerdin@7659: 
mgerdin@7659:   OopClosure* const weak_roots = &buf_scan_non_heap_weak_roots;
mgerdin@7659:   OopClosure* const strong_roots = &buf_scan_non_heap_roots;
mgerdin@7659: 
mgerdin@7659:   // CodeBlobClosures are not interoperable with BufferingOopClosures
mgerdin@7659:   G1CodeBlobClosure root_code_blobs(scan_non_heap_roots);
mgerdin@7659: 
mgerdin@7659:   process_java_roots(strong_roots,
mgerdin@7659:                      trace_metadata ? scan_strong_clds : NULL,
mgerdin@7659:                      scan_strong_clds,
mgerdin@7659:                      trace_metadata ? NULL : scan_weak_clds,
brutisso@7660:                      &root_code_blobs,
brutisso@7660:                      phase_times,
brutisso@7660:                      worker_i);
mgerdin@7659: 
mgerdin@7659:   // This is the point where this worker thread will not find more strong CLDs/nmethods.
mgerdin@7659:   // Report this so G1 can synchronize the strong and weak CLDs/nmethods processing.
mgerdin@7659:   if (trace_metadata) {
mgerdin@7659:     worker_has_discovered_all_strong_classes();
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   process_vm_roots(strong_roots, weak_roots, phase_times, worker_i);
fmatte@9358:   process_string_table_roots(weak_roots, phase_times, worker_i);
brutisso@7660:   {
brutisso@7660:     // Now the CM ref_processor roots.
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CMRefRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_refProcessor_oops_do)) {
brutisso@7660:       // We need to treat the discovered reference lists of the
brutisso@7660:       // concurrent mark ref processor as roots and keep entries
brutisso@7660:       // (which are added by the marking threads) on them live
brutisso@7660:       // until they can be processed at the end of marking.
brutisso@7660:       _g1h->ref_processor_cm()->weak_oops_do(&buf_scan_non_heap_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
mgerdin@7659:   if (trace_metadata) {
brutisso@7660:     {
brutisso@7660:       G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::WaitForStrongCLD, worker_i);
brutisso@7660:       // Barrier to make sure all workers passed
brutisso@7660:       // the strong CLD and strong nmethods phases.
brutisso@7660:       wait_until_all_strong_classes_discovered();
brutisso@7660:     }
mgerdin@7659: 
mgerdin@7659:     // Now take the complement of the strong CLDs.
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::WeakCLDRoots, worker_i);
mgerdin@7659:     ClassLoaderDataGraph::roots_cld_do(NULL, scan_weak_clds);
brutisso@7660:   } else {
brutisso@7660:     phase_times->record_time_secs(G1GCPhaseTimes::WaitForStrongCLD, worker_i, 0.0);
brutisso@7660:     phase_times->record_time_secs(G1GCPhaseTimes::WeakCLDRoots, worker_i, 0.0);
mgerdin@7659:   }
mgerdin@7659: 
mgerdin@7659:   // Finish up any enqueued closure apps (attributed as object copy time).
mgerdin@7659:   buf_scan_non_heap_roots.done();
mgerdin@7659:   buf_scan_non_heap_weak_roots.done();
mgerdin@7659: 
mgerdin@7659:   double obj_copy_time_sec = buf_scan_non_heap_roots.closure_app_seconds()
mgerdin@7659:       + buf_scan_non_heap_weak_roots.closure_app_seconds();
mgerdin@7659: 
mgerdin@7659:   phase_times->record_time_secs(G1GCPhaseTimes::ObjCopy, worker_i, obj_copy_time_sec);
mgerdin@7659: 
mgerdin@7659:   double ext_root_time_sec = os::elapsedTime() - ext_roots_start - obj_copy_time_sec;
mgerdin@7659: 
mgerdin@7659:   phase_times->record_time_secs(G1GCPhaseTimes::ExtRootScan, worker_i, ext_root_time_sec);
mgerdin@7659: 
mgerdin@7659:   // During conc marking we have to filter the per-thread SATB buffers
mgerdin@7659:   // to make sure we remove any oops into the CSet (which will show up
mgerdin@7659:   // as implicitly live).
mgerdin@7659:   {
mgerdin@7659:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::SATBFiltering, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_filter_satb_buffers) && _g1h->mark_in_progress()) {
mgerdin@7659:       JavaThread::satb_mark_queue_set().filter_thread_buffers();
mgerdin@7659:     }
mgerdin@7659:   }
mgerdin@7659: 
mgerdin@8070:   _process_strong_tasks.all_tasks_completed();
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::process_strong_roots(OopClosure* oops,
mgerdin@7659:                                            CLDClosure* clds,
mgerdin@7659:                                            CodeBlobClosure* blobs) {
mgerdin@7659: 
brutisso@7660:   process_java_roots(oops, clds, clds, NULL, blobs, NULL, 0);
brutisso@7660:   process_vm_roots(oops, NULL, NULL, 0);
mgerdin@7659: 
mgerdin@8070:   _process_strong_tasks.all_tasks_completed();
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::process_all_roots(OopClosure* oops,
mgerdin@7659:                                         CLDClosure* clds,
fmatte@9358:                                         CodeBlobClosure* blobs,
fmatte@9358:                                         bool process_string_table) {
mgerdin@7659: 
brutisso@7660:   process_java_roots(oops, NULL, clds, clds, NULL, NULL, 0);
brutisso@7660:   process_vm_roots(oops, oops, NULL, 0);
mgerdin@7659: 
fmatte@9358:   if (process_string_table) {
fmatte@9358:     process_string_table_roots(oops, NULL, 0);
fmatte@9358:    }
fmatte@9358:   process_code_cache_roots(blobs, NULL, 0);
mgerdin@7659: 
mgerdin@8070:   _process_strong_tasks.all_tasks_completed();
mgerdin@7659: }
mgerdin@7659: 
fmatte@9358: void G1RootProcessor::process_all_roots(OopClosure* oops,
fmatte@9358:                                         CLDClosure* clds,
fmatte@9358:                                         CodeBlobClosure* blobs) {
fmatte@9358:   process_all_roots(oops, clds, blobs, true);
fmatte@9358: }
fmatte@9358: 
fmatte@9358: void G1RootProcessor::process_all_roots_no_string_table(OopClosure* oops,
fmatte@9358:                                                         CLDClosure* clds,
fmatte@9358:                                                         CodeBlobClosure* blobs) {
fmatte@9358:   assert(!ClassUnloading, "Should only be used when class unloading is disabled");
fmatte@9358:   process_all_roots(oops, clds, blobs, false);
fmatte@9358: }
fmatte@9358: 
fmatte@9358: 
mgerdin@7659: void G1RootProcessor::process_java_roots(OopClosure* strong_roots,
mgerdin@7659:                                          CLDClosure* thread_stack_clds,
mgerdin@7659:                                          CLDClosure* strong_clds,
mgerdin@7659:                                          CLDClosure* weak_clds,
brutisso@7660:                                          CodeBlobClosure* strong_code,
brutisso@7660:                                          G1GCPhaseTimes* phase_times,
brutisso@7660:                                          uint worker_i) {
mgerdin@7659:   assert(thread_stack_clds == NULL || weak_clds == NULL, "There is overlap between those, only one may be set");
mgerdin@7659:   // Iterating over the CLDG and the Threads are done early to allow us to
mgerdin@7659:   // first process the strong CLDs and nmethods and then, after a barrier,
mgerdin@7659:   // let the thread process the weak CLDs and nmethods.
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CLDGRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_ClassLoaderDataGraph_oops_do)) {
brutisso@7660:       ClassLoaderDataGraph::roots_cld_do(strong_clds, weak_clds);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ThreadRoots, worker_i);
brutisso@7660:     Threads::possibly_parallel_oops_do(strong_roots, thread_stack_clds, strong_code);
brutisso@7660:   }
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::process_vm_roots(OopClosure* strong_roots,
brutisso@7660:                                        OopClosure* weak_roots,
brutisso@7660:                                        G1GCPhaseTimes* phase_times,
brutisso@7660:                                        uint worker_i) {
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::UniverseRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_Universe_oops_do)) {
brutisso@7660:       Universe::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JNIRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_JNIHandles_oops_do)) {
brutisso@7660:       JNIHandles::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ObjectSynchronizerRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_ObjectSynchronizer_oops_do)) {
brutisso@7660:       ObjectSynchronizer::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::FlatProfilerRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_FlatProfiler_oops_do)) {
brutisso@7660:       FlatProfiler::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::ManagementRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_Management_oops_do)) {
brutisso@7660:       Management::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::JVMTIRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_jvmti_oops_do)) {
brutisso@7660:       JvmtiExport::oops_do(strong_roots);
brutisso@7660:     }
mgerdin@7659:   }
mgerdin@7659: 
brutisso@7660:   {
brutisso@7660:     G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::SystemDictionaryRoots, worker_i);
mgerdin@8070:     if (!_process_strong_tasks.is_task_claimed(G1RP_PS_SystemDictionary_oops_do)) {
brutisso@7660:       SystemDictionary::roots_oops_do(strong_roots, weak_roots);
brutisso@7660:     }
mgerdin@7659:   }
fmatte@9358: }
mgerdin@7659: 
fmatte@9358: void G1RootProcessor::process_string_table_roots(OopClosure* weak_roots, G1GCPhaseTimes* phase_times,
fmatte@9358:                                                  uint worker_i) {
fmatte@9358:   assert(weak_roots != NULL, "Should only be called when all roots are processed");
fmatte@9358: 
fmatte@9358:   G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::StringTableRoots, worker_i);
fmatte@9358:   // All threads execute the following. A specific chunk of buckets
fmatte@9358:   // from the StringTable are the individual tasks.
fmatte@9358:   StringTable::possibly_parallel_oops_do(weak_roots);
fmatte@9358: }
fmatte@9358: 
fmatte@9358: void G1RootProcessor::process_code_cache_roots(CodeBlobClosure* code_closure,
fmatte@9358:                                                G1GCPhaseTimes* phase_times,
fmatte@9358:                                                uint worker_i) {
fmatte@9358:   if (!_process_strong_tasks.is_task_claimed(G1RP_PS_CodeCache_oops_do)) {
fmatte@9358:     CodeCache::blobs_do(code_closure);
mgerdin@7659:   }
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::scan_remembered_sets(G1ParPushHeapRSClosure* scan_rs,
mgerdin@7659:                                            OopClosure* scan_non_heap_weak_roots,
mgerdin@7659:                                            uint worker_i) {
brutisso@7660:   G1GCPhaseTimes* phase_times = _g1h->g1_policy()->phase_times();
brutisso@7660:   G1GCParPhaseTimesTracker x(phase_times, G1GCPhaseTimes::CodeCacheRoots, worker_i);
brutisso@7660: 
mgerdin@7659:   // Now scan the complement of the collection set.
mgerdin@7659:   G1CodeBlobClosure scavenge_cs_nmethods(scan_non_heap_weak_roots);
mgerdin@7659: 
mgerdin@7659:   _g1h->g1_rem_set()->oops_into_collection_set_do(scan_rs, &scavenge_cs_nmethods, worker_i);
mgerdin@7659: }
mgerdin@7659: 
mgerdin@7659: void G1RootProcessor::set_num_workers(int active_workers) {
mgerdin@8070:   _process_strong_tasks.set_n_threads(active_workers);
mgerdin@7659: }