1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/g1/g1CollectedHeap.hpp"
  27 #include "gc/g1/g1FullCollector.hpp"
  28 #include "gc/g1/g1FullGCMarker.hpp"
  29 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
  30 #include "gc/g1/g1FullGCReferenceProcessorExecutor.hpp"
  31 #include "gc/shared/gcTraceTime.inline.hpp"
  32 #include "gc/shared/referenceProcessor.hpp"
  33 
  34 G1FullGCReferenceProcessingExecutor::G1FullGCReferenceProcessingExecutor(G1FullCollector* collector) :
  35     _collector(collector),
  36     _reference_processor(collector->reference_processor()),
  37     _old_mt_degree(_reference_processor->num_q()) {
  38   if (_reference_processor->processing_is_mt()) {
  39     _reference_processor->set_active_mt_degree(_collector->workers());
  40   }
  41 }
  42 
  43 G1FullGCReferenceProcessingExecutor::~G1FullGCReferenceProcessingExecutor() {
  44   if (_reference_processor->processing_is_mt()) {
  45     _reference_processor->set_active_mt_degree(_old_mt_degree);
  46   }
  47 }
  48 
  49 G1FullGCReferenceProcessingExecutor::G1RefProcTaskProxy::G1RefProcTaskProxy(ProcessTask& proc_task,
  50                                                                       G1FullCollector* collector) :
  51      AbstractGangTask("G1 reference processing task"),
  52      _proc_task(proc_task),
  53      _collector(collector),
  54      _terminator(_collector->workers(), _collector->oop_queue_set()) { }
  55 
  56 void G1FullGCReferenceProcessingExecutor::G1RefProcTaskProxy::work(uint worker_id) {
  57   G1FullGCMarker* marker = _collector->marker(worker_id);
  58   G1IsAliveClosure is_alive(_collector->mark_bitmap());
  59   G1FullKeepAliveClosure keep_alive(marker);
  60   _proc_task.work(worker_id,
  61                   is_alive,
  62                   keep_alive,
  63                   *marker->stack_closure());
  64 }
  65 
  66 G1FullGCReferenceProcessingExecutor::G1RefEnqueueTaskProxy::G1RefEnqueueTaskProxy(EnqueueTask& enq_task) :
  67   AbstractGangTask("G1 reference enqueue task"),
  68   _enq_task(enq_task) { }
  69 
  70 void G1FullGCReferenceProcessingExecutor::G1RefEnqueueTaskProxy::work(uint worker_id) {
  71   _enq_task.work(worker_id);
  72 }
  73 
  74 void G1FullGCReferenceProcessingExecutor::run_task(AbstractGangTask* task) {
  75   G1CollectedHeap::heap()->workers()->run_task(task, _collector->workers());
  76 }
  77 
  78 void G1FullGCReferenceProcessingExecutor::execute(ProcessTask& proc_task) {
  79   G1RefProcTaskProxy proc_task_proxy(proc_task, _collector);
  80   run_task(&proc_task_proxy);
  81 }
  82 
  83 // Driver routine for parallel reference processing.
  84 void G1FullGCReferenceProcessingExecutor::execute(EnqueueTask& enq_task) {
  85   G1RefEnqueueTaskProxy enq_task_proxy(enq_task);
  86   run_task(&enq_task_proxy);
  87 }
  88 
  89 void G1FullGCReferenceProcessingExecutor::execute(STWGCTimer* timer, G1FullGCTracer* tracer) {
  90   GCTraceTime(Debug, gc, phases) debug("Phase 1: Reference Processing", timer);
  91   // Process reference objects found during marking.
  92   G1FullGCMarker* marker = _collector->marker(0);
  93   G1IsAliveClosure is_alive(_collector->mark_bitmap());
  94   G1FullKeepAliveClosure keep_alive(marker);
  95   ReferenceProcessorPhaseTimes pt(timer, _reference_processor->num_q());
  96   AbstractRefProcTaskExecutor* executor = _reference_processor->processing_is_mt() ? this : NULL;
  97 
  98   // Process discovered references, use this executor if multi-threaded
  99   // processing is enabled.
 100   const ReferenceProcessorStats& stats =
 101       _reference_processor->process_discovered_references(&is_alive,
 102                                                           &keep_alive,
 103                                                           marker->stack_closure(),
 104                                                           executor,
 105                                                           &pt);
 106 
 107   tracer->report_gc_reference_stats(stats);
 108   pt.print_all_references();
 109 
 110   assert(marker->oop_stack()->is_empty(), "Should be no oops on the stack");
 111 
 112   // Now enqueue the references.
 113   _reference_processor->enqueue_discovered_references(executor, &pt);
 114   pt.print_enqueue_phase();
 115 }