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/cms/cmsCardTable.hpp"
  27 #include "gc/cms/compactibleFreeListSpace.hpp"
  28 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
  29 #include "gc/cms/concurrentMarkSweepThread.hpp"
  30 #include "gc/cms/cmsHeap.hpp"
  31 #include "gc/cms/parNewGeneration.hpp"
  32 #include "gc/cms/vmCMSOperations.hpp"
  33 #include "gc/shared/genMemoryPools.hpp"
  34 #include "gc/shared/genOopClosures.inline.hpp"
  35 #include "gc/shared/strongRootsScope.hpp"
  36 #include "gc/shared/workgroup.hpp"
  37 #include "oops/oop.inline.hpp"
  38 #include "runtime/vmThread.hpp"
  39 #include "services/memoryManager.hpp"
  40 #include "utilities/stack.inline.hpp"
  41 
  42 class CompactibleFreeListSpacePool : public CollectedMemoryPool {
  43 private:
  44   CompactibleFreeListSpace* _space;
  45 public:
  46   CompactibleFreeListSpacePool(CompactibleFreeListSpace* space,
  47                                const char* name,
  48                                size_t max_size,
  49                                bool support_usage_threshold) :
  50     CollectedMemoryPool(name, space->capacity(), max_size, support_usage_threshold),
  51     _space(space) {
  52   }
  53 
  54   MemoryUsage get_memory_usage() {
  55     size_t max_heap_size   = (available_for_allocation() ? max_size() : 0);
  56     size_t used      = used_in_bytes();
  57     size_t committed = _space->capacity();
  58 
  59     return MemoryUsage(initial_size(), used, committed, max_heap_size);
  60   }
  61 
  62   size_t used_in_bytes() {
  63     return _space->used();
  64   }
  65 };
  66 
  67 CMSHeap::CMSHeap(GenCollectorPolicy *policy) :
  68     GenCollectedHeap(policy,
  69                      Generation::ParNew,
  70                      Generation::ConcurrentMarkSweep,
  71                      "ParNew::CMS"),
  72     _eden_pool(NULL),
  73     _survivor_pool(NULL),
  74     _old_pool(NULL) {
  75   _workers = new WorkGang("GC Thread", ParallelGCThreads,
  76                           /* are_GC_task_threads */true,
  77                           /* are_ConcurrentGC_threads */false);
  78   _workers->initialize_workers();
  79 }
  80 
  81 jint CMSHeap::initialize() {
  82   jint status = GenCollectedHeap::initialize();
  83   if (status != JNI_OK) return status;
  84 
  85   // If we are running CMS, create the collector responsible
  86   // for collecting the CMS generations.
  87   if (!create_cms_collector()) {
  88     return JNI_ENOMEM;
  89   }
  90 
  91   return JNI_OK;
  92 }
  93 
  94 CardTableRS* CMSHeap::create_rem_set(const MemRegion& reserved_region) {
  95   return new CMSCardTable(reserved_region);
  96 }
  97 
  98 void CMSHeap::initialize_serviceability() {
  99   _young_manager = new GCMemoryManager("ParNew", "end of minor GC");
 100   _old_manager = new GCMemoryManager("ConcurrentMarkSweep", "end of major GC");
 101 
 102   ParNewGeneration* young = (ParNewGeneration*) young_gen();
 103   _eden_pool = new ContiguousSpacePool(young->eden(),
 104                                        "Par Eden Space",
 105                                        young->max_eden_size(),
 106                                        false);
 107 
 108   _survivor_pool = new SurvivorContiguousSpacePool(young,
 109                                                    "Par Survivor Space",
 110                                                    young->max_survivor_size(),
 111                                                    false);
 112 
 113   ConcurrentMarkSweepGeneration* old = (ConcurrentMarkSweepGeneration*) old_gen();
 114   _old_pool = new CompactibleFreeListSpacePool(old->cmsSpace(),
 115                                                "CMS Old Gen",
 116                                                old->reserved().byte_size(),
 117                                                true);
 118 
 119   _young_manager->add_pool(_eden_pool);
 120   _young_manager->add_pool(_survivor_pool);
 121   young->set_gc_manager(_young_manager);
 122 
 123   _old_manager->add_pool(_eden_pool);
 124   _old_manager->add_pool(_survivor_pool);
 125   _old_manager->add_pool(_old_pool);
 126   old ->set_gc_manager(_old_manager);
 127 
 128 }
 129 
 130 void CMSHeap::check_gen_kinds() {
 131   assert(young_gen()->kind() == Generation::ParNew,
 132          "Wrong youngest generation type");
 133   assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
 134          "Wrong generation kind");
 135 }
 136 
 137 CMSHeap* CMSHeap::heap() {
 138   CollectedHeap* heap = Universe::heap();
 139   assert(heap != NULL, "Uninitialized access to CMSHeap::heap()");
 140   assert(heap->kind() == CollectedHeap::CMS, "Invalid name");
 141   return (CMSHeap*) heap;
 142 }
 143 
 144 void CMSHeap::gc_threads_do(ThreadClosure* tc) const {
 145   assert(workers() != NULL, "should have workers here");
 146   workers()->threads_do(tc);
 147   ConcurrentMarkSweepThread::threads_do(tc);
 148 }
 149 
 150 void CMSHeap::print_gc_threads_on(outputStream* st) const {
 151   assert(workers() != NULL, "should have workers here");
 152   workers()->print_worker_threads_on(st);
 153   ConcurrentMarkSweepThread::print_all_on(st);
 154 }
 155 
 156 void CMSHeap::print_on_error(outputStream* st) const {
 157   GenCollectedHeap::print_on_error(st);
 158   st->cr();
 159   CMSCollector::print_on_error(st);
 160 }
 161 
 162 bool CMSHeap::create_cms_collector() {
 163   assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
 164          "Unexpected generation kinds");
 165   CMSCollector* collector =
 166     new CMSCollector((ConcurrentMarkSweepGeneration*) old_gen(),
 167                      rem_set(),
 168                      (ConcurrentMarkSweepPolicy*) gen_policy());
 169 
 170   if (collector == NULL || !collector->completed_initialization()) {
 171     if (collector) {
 172       delete collector; // Be nice in embedded situation
 173     }
 174     vm_shutdown_during_initialization("Could not create CMS collector");
 175     return false;
 176   }
 177   return true; // success
 178 }
 179 
 180 void CMSHeap::collect(GCCause::Cause cause) {
 181   if (should_do_concurrent_full_gc(cause)) {
 182     // Mostly concurrent full collection.
 183     collect_mostly_concurrent(cause);
 184   } else {
 185     GenCollectedHeap::collect(cause);
 186   }
 187 }
 188 
 189 bool CMSHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
 190   switch (cause) {
 191     case GCCause::_gc_locker:           return GCLockerInvokesConcurrent;
 192     case GCCause::_java_lang_system_gc:
 193     case GCCause::_dcmd_gc_run:         return ExplicitGCInvokesConcurrent;
 194     default:                            return false;
 195   }
 196 }
 197 
 198 void CMSHeap::collect_mostly_concurrent(GCCause::Cause cause) {
 199   assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
 200 
 201   MutexLocker ml(Heap_lock);
 202   // Read the GC counts while holding the Heap_lock
 203   unsigned int full_gc_count_before = total_full_collections();
 204   unsigned int gc_count_before      = total_collections();
 205   {
 206     MutexUnlocker mu(Heap_lock);
 207     VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
 208     VMThread::execute(&op);
 209   }
 210 }
 211 
 212 void CMSHeap::stop() {
 213   ConcurrentMarkSweepThread::cmst()->stop();
 214 }
 215 
 216 void CMSHeap::safepoint_synchronize_begin() {
 217   ConcurrentMarkSweepThread::synchronize(false);
 218 }
 219 
 220 void CMSHeap::safepoint_synchronize_end() {
 221   ConcurrentMarkSweepThread::desynchronize(false);
 222 }
 223 
 224 void CMSHeap::cms_process_roots(StrongRootsScope* scope,
 225                                 bool young_gen_as_roots,
 226                                 ScanningOption so,
 227                                 bool only_strong_roots,
 228                                 OopsInGenClosure* root_closure,
 229                                 CLDClosure* cld_closure) {
 230   MarkingCodeBlobClosure mark_code_closure(root_closure, !CodeBlobToOopClosure::FixRelocations);
 231   OopsInGenClosure* weak_roots = only_strong_roots ? NULL : root_closure;
 232   CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
 233 
 234   process_roots(scope, so, root_closure, weak_roots, cld_closure, weak_cld_closure, &mark_code_closure);
 235   if (!only_strong_roots) {
 236     process_string_table_roots(scope, root_closure);
 237   }
 238 
 239   if (young_gen_as_roots &&
 240       !_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
 241     root_closure->set_generation(young_gen());
 242     young_gen()->oop_iterate(root_closure);
 243     root_closure->reset_generation();
 244   }
 245 
 246   _process_strong_tasks->all_tasks_completed(scope->n_threads());
 247 }
 248 
 249 void CMSHeap::gc_prologue(bool full) {
 250   always_do_update_barrier = false;
 251   GenCollectedHeap::gc_prologue(full);
 252 };
 253 
 254 void CMSHeap::gc_epilogue(bool full) {
 255   GenCollectedHeap::gc_epilogue(full);
 256   always_do_update_barrier = true;
 257 };
 258 
 259 GrowableArray<GCMemoryManager*> CMSHeap::memory_managers() {
 260   GrowableArray<GCMemoryManager*> memory_managers(2);
 261   memory_managers.append(_young_manager);
 262   memory_managers.append(_old_manager);
 263   return memory_managers;
 264 }
 265 
 266 GrowableArray<MemoryPool*> CMSHeap::memory_pools() {
 267   GrowableArray<MemoryPool*> memory_pools(3);
 268   memory_pools.append(_eden_pool);
 269   memory_pools.append(_survivor_pool);
 270   memory_pools.append(_old_pool);
 271   return memory_pools;
 272 }