jdk-sandbox: comparison hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp

equal deleted inserted replaced

-:70fb742e40aa
+:d27050bdfb04
 *
 */
 #include "precompiled.hpp"
 #include "classfile/symbolTable.hpp"
+#include "code/codeCache.hpp"
 #include "gc_implementation/g1/concurrentMark.inline.hpp"
 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "gc_implementation/shared/vmGCOperations.hpp"
 #include "gc_implementation/shared/gcTimer.hpp"
 #include "gc_implementation/shared/gcTrace.hpp"
 #include "gc_implementation/shared/gcTraceTime.hpp"
+#include "memory/allocation.hpp"
 #include "memory/genOopClosures.inline.hpp"
 #include "memory/referencePolicy.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/handles.inline.hpp"
 _shifter(shifter) {
 _bmStartWord = 0;
 _bmWordSize = 0;
 }
-HeapWord* CMBitMapRO::getNextMarkedWordAddress(HeapWord* addr,
+HeapWord* CMBitMapRO::getNextMarkedWordAddress(const HeapWord* addr,
-HeapWord* limit) const {
+const HeapWord* limit) const {
 // First we must round addr *up* to a possible object boundary.
 addr = (HeapWord*)align_size_up((intptr_t)addr,
 HeapWordSize << _shifter);
 size_t addrOffset = heapWordToOffset(addr);
 if (limit == NULL) {
 assert(nextAddr == limit || isMarked(nextAddr),
 "get_next_one postcondition");
 return nextAddr;
 }
-HeapWord* CMBitMapRO::getNextUnmarkedWordAddress(HeapWord* addr,
+HeapWord* CMBitMapRO::getNextUnmarkedWordAddress(const HeapWord* addr,
-HeapWord* limit) const {
+const HeapWord* limit) const {
 size_t addrOffset = heapWordToOffset(addr);
 if (limit == NULL) {
 limit = _bmStartWord + _bmWordSize;
 }
 size_t limitOffset = heapWordToOffset(limit);
 }
 }
 };
 void ConcurrentMark::scanRootRegions() {
+// Start of concurrent marking.
+ClassLoaderDataGraph::clear_claimed_marks();
 // scan_in_progress() will have been set to true only if there was
 // at least one root region to scan. So, if it's false, we
 // should not attempt to do any further work.
 if (root_regions()->scan_in_progress()) {
 _parallel_marking_threads = calc_parallel_marking_threads();
 set_concurrency_and_phase(active_workers, true /* concurrent */);
 CMConcurrentMarkingTask markingTask(this, cmThread());
 if (use_parallel_marking_threads()) {
 _parallel_workers->set_active_workers((int)active_workers);
-// Don't set _n_par_threads because it affects MT in process_strong_roots()
+// Don't set _n_par_threads because it affects MT in process_roots()
 // and the decisions on that MT processing is made elsewhere.
 assert(_parallel_workers->active_workers() > 0, "Should have been set");
 _parallel_workers->run_task(&markingTask);
 } else {
 markingTask.work(0);
 // Clean up will have freed any regions completely full of garbage.
 // Update the soft reference policy with the new heap occupancy.
 Universe::update_heap_info_at_gc();
-// We need to make this be a "collection" so any collection pause that
-// races with it goes around and waits for completeCleanup to finish.
-g1h->increment_total_collections();
-// We reclaimed old regions so we should calculate the sizes to make
-// sure we update the old gen/space data.
-g1h->g1mm()->update_sizes();
 if (VerifyDuringGC) {
 HandleMark hm;  // handle scope
 Universe::heap()->prepare_for_verify();
 Universe::verify(VerifyOption_G1UsePrevMarking,
 " VerifyDuringGC:(after)");
 }
 g1h->check_bitmaps("Cleanup End");
 g1h->verify_region_sets_optional();
+// We need to make this be a "collection" so any collection pause that
+// races with it goes around and waits for completeCleanup to finish.
+g1h->increment_total_collections();
+// Clean out dead classes and update Metaspace sizes.
+ClassLoaderDataGraph::purge();
+MetaspaceGC::compute_new_size();
+// We reclaimed old regions so we should calculate the sizes to make
+// sure we update the old gen/space data.
+g1h->g1mm()->update_sizes();
 g1h->trace_heap_after_concurrent_cycle();
 }
 void ConcurrentMark::completeCleanup() {
 if (has_aborted()) return;
 _g1h->set_par_threads(_active_workers);
 _workers->run_task(&enq_task_proxy);
 _g1h->set_par_threads(0);
 }
+void ConcurrentMark::weakRefsWorkParallelPart(BoolObjectClosure* is_alive, bool purged_classes) {
+G1CollectedHeap::heap()->parallel_cleaning(is_alive, true, true, purged_classes);
+}
+// Helper class to get rid of some boilerplate code.
+class G1RemarkGCTraceTime : public GCTraceTime {
+static bool doit_and_prepend(bool doit) {
+if (doit) {
+gclog_or_tty->put(' ');
+}
+return doit;
+}
+public:
+G1RemarkGCTraceTime(const char* title, bool doit)
+: GCTraceTime(title, doit_and_prepend(doit), false, G1CollectedHeap::heap()->gc_timer_cm(),
+G1CollectedHeap::heap()->concurrent_mark()->concurrent_gc_id()) {
+}
+};
 void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) {
 if (has_overflown()) {
 // Skip processing the discovered references if we have
 // overflown the global marking stack. Reference objects
 // only get discovered once so it is OK to not
 if (has_overflown()) {
 // We can not trust g1_is_alive if the marking stack overflowed
 return;
 }
-g1h->unlink_string_and_symbol_table(&g1_is_alive,
+assert(_markStack.isEmpty(), "Marking should have completed");
-/* process_strings */ false, // currently strings are always roots
-/* process_symbols */ true);
+// Unload Klasses, String, Symbols, Code Cache, etc.
+G1RemarkGCTraceTime trace("Unloading", G1Log::finer());
+bool purged_classes;
+{
+G1RemarkGCTraceTime trace("System Dictionary Unloading", G1Log::finest());
+purged_classes = SystemDictionary::do_unloading(&g1_is_alive);
+}
+{
+G1RemarkGCTraceTime trace("Parallel Unloading", G1Log::finest());
+weakRefsWorkParallelPart(&g1_is_alive, purged_classes);
+}
+if (G1StringDedup::is_enabled()) {
+G1RemarkGCTraceTime trace("String Deduplication Unlink", G1Log::finest());
+G1StringDedup::unlink(&g1_is_alive);
+}
 }
 void ConcurrentMark::swapMarkBitMaps() {
 CMBitMapRO* temp = _prevMarkBitMap;
 _prevMarkBitMap  = (CMBitMapRO*)_nextMarkBitMap;
 _nextMarkBitMap  = (CMBitMap*)  temp;
 }
+class CMObjectClosure;
+// Closure for iterating over objects, currently only used for
+// processing SATB buffers.
+class CMObjectClosure : public ObjectClosure {
+private:
+CMTask* _task;
+public:
+void do_object(oop obj) {
+_task->deal_with_reference(obj);
+}
+CMObjectClosure(CMTask* task) : _task(task) { }
+};
+class G1RemarkThreadsClosure : public ThreadClosure {
+CMObjectClosure _cm_obj;
+G1CMOopClosure _cm_cl;
+MarkingCodeBlobClosure _code_cl;
+int _thread_parity;
+bool _is_par;
+public:
+G1RemarkThreadsClosure(G1CollectedHeap* g1h, CMTask* task, bool is_par) :
+_cm_obj(task), _cm_cl(g1h, g1h->concurrent_mark(), task), _code_cl(&_cm_cl, !CodeBlobToOopClosure::FixRelocations),
+_thread_parity(SharedHeap::heap()->strong_roots_parity()), _is_par(is_par) {}
+void do_thread(Thread* thread) {
+if (thread->is_Java_thread()) {
+if (thread->claim_oops_do(_is_par, _thread_parity)) {
+JavaThread* jt = (JavaThread*)thread;
+// In theory it should not be neccessary to explicitly walk the nmethods to find roots for concurrent marking
+// however the liveness of oops reachable from nmethods have very complex lifecycles:
+// * Alive if on the stack of an executing method
+// * Weakly reachable otherwise
+// Some objects reachable from nmethods, such as the class loader (or klass_holder) of the receiver should be
+// live by the SATB invariant but other oops recorded in nmethods may behave differently.
+jt->nmethods_do(&_code_cl);
+jt->satb_mark_queue().apply_closure_and_empty(&_cm_obj);
+}
+} else if (thread->is_VM_thread()) {
+if (thread->claim_oops_do(_is_par, _thread_parity)) {
+JavaThread::satb_mark_queue_set().shared_satb_queue()->apply_closure_and_empty(&_cm_obj);
+}
+}
+}
+};
 class CMRemarkTask: public AbstractGangTask {
 private:
 ConcurrentMark* _cm;
 bool            _is_serial;
 // Since all available tasks are actually started, we should
 // only proceed if we're supposed to be active.
 if (worker_id < _cm->active_tasks()) {
 CMTask* task = _cm->task(worker_id);
 task->record_start_time();
+{
+ResourceMark rm;
+HandleMark hm;
+G1RemarkThreadsClosure threads_f(G1CollectedHeap::heap(), task, !_is_serial);
+Threads::threads_do(&threads_f);
+}
 do {
 task->do_marking_step(1000000000.0 /* something very large */,
 true         /* do_termination       */,
 _is_serial);
 } while (task->has_aborted() && !_cm->has_overflown());
 void ConcurrentMark::checkpointRootsFinalWork() {
 ResourceMark rm;
 HandleMark   hm;
 G1CollectedHeap* g1h = G1CollectedHeap::heap();
+G1RemarkGCTraceTime trace("Finalize Marking", G1Log::finer());
 g1h->ensure_parsability(false);
 if (G1CollectedHeap::use_parallel_gc_threads()) {
 G1CollectedHeap::StrongRootsScope srs(g1h);
 // the iteration
 return !_task->has_aborted();
 }
 };
-// Closure for iterating over objects, currently only used for
-// processing SATB buffers.
-class CMObjectClosure : public ObjectClosure {
-private:
-CMTask* _task;
-public:
-void do_object(oop obj) {
-_task->deal_with_reference(obj);
-}
-CMObjectClosure(CMTask* task) : _task(task) { }
-};
 G1CMOopClosure::G1CMOopClosure(G1CollectedHeap* g1h,
 ConcurrentMark* cm,
 CMTask* task)
 : _g1h(g1h), _cm(cm), _task(task) {
 assert(_ref_processor == NULL, "should be initialized to NULL");
 if (_cm->verbose_medium()) {
 gclog_or_tty->print_cr("[%u] processed an SATB buffer", _worker_id);
 }
 statsOnly( ++_satb_buffers_processed );
 regular_clock_call();
-}
-}
-if (!concurrent() && !has_aborted()) {
-// We should only do this during remark.
-if (G1CollectedHeap::use_parallel_gc_threads()) {
-satb_mq_set.par_iterate_closure_all_threads(_worker_id);
-} else {
-satb_mq_set.iterate_closure_all_threads();
 }
 }
 _draining_satb_buffers = false;

changeset 25492	d27050bdfb04
parent 25491	70fb742e40aa
child 25728	7f8a76e3baa8