8251158: Implementation of JEP 387: Elastic Metaspace

Reviewed-by: lkorinth, coleenp, iklam, rrich

src/hotspot/share/classfile/classLoaderData.cpp

@@ -58,7 +58,9 @@
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
 #include "memory/allocation.inline.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "memory/metadataFactory.hpp"
+#include "memory/metaspace.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
 #include "oops/access.inline.hpp"
@@ -953,9 +955,11 @@ void ClassLoaderData::verify() {
   guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || has_class_mirror_holder(), "must be");
 
   // Verify the integrity of the allocated space.
+#ifdef ASSERT
   if (metaspace_or_null() != NULL) {
     metaspace_or_null()->verify();
   }
+#endif
 
   for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
     guarantee(k->class_loader_data() == this, "Must be the same");

src/hotspot/share/classfile/classLoaderData.hpp

@@ -62,6 +62,7 @@ class ModuleEntryTable;
 class PackageEntryTable;
 class DictionaryEntry;
 class Dictionary;
+class ClassLoaderMetaspace;
 
 // ClassLoaderData class
 

src/hotspot/share/classfile/classLoaderDataGraph.cpp

@@ -661,24 +661,6 @@ Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass() {
   return NULL;
 }
 
-ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
-  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
-  _data = ClassLoaderDataGraph::_head;
-}
-
-ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
-
-ClassLoaderMetaspace* ClassLoaderDataGraphMetaspaceIterator::get_next() {
-  assert(_data != NULL, "Should not be NULL in call to the iterator");
-  ClassLoaderMetaspace* result = _data->metaspace_or_null();
-  _data = _data->next();
-  // This result might be NULL for class loaders without metaspace
-  // yet.  It would be nice to return only non-null results but
-  // there is no guarantee that there will be a non-null result
-  // down the list so the caller is going to have to check.
-  return result;
-}
-
 void ClassLoaderDataGraph::verify() {
   ClassLoaderDataGraphIterator iter;
   while (ClassLoaderData* cld = iter.get_next()) {

src/hotspot/share/classfile/classLoaderDataGraph.hpp

@@ -162,12 +162,4 @@ class ClassLoaderDataGraphKlassIteratorAtomic : public StackObj {
   static Klass* next_klass_in_cldg(Klass* klass);
 };
 
-class ClassLoaderDataGraphMetaspaceIterator : public StackObj {
-  ClassLoaderData* _data;
- public:
-  ClassLoaderDataGraphMetaspaceIterator();
-  ~ClassLoaderDataGraphMetaspaceIterator();
-  bool repeat() { return _data != NULL; }
-  ClassLoaderMetaspace* get_next();
-};
 #endif // SHARE_CLASSFILE_CLASSLOADERDATAGRAPH_HPP

src/hotspot/share/classfile/classLoaderStats.cpp

@@ -26,6 +26,7 @@
 #include "classfile/classLoaderData.inline.hpp"
 #include "classfile/classLoaderDataGraph.hpp"
 #include "classfile/classLoaderStats.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "oops/objArrayKlass.hpp"
 #include "oops/oop.inline.hpp"
 #include "utilities/globalDefinitions.hpp"
@@ -80,15 +81,17 @@ void ClassLoaderStatsClosure::do_cld(ClassLoaderData* cld) {
 
   ClassLoaderMetaspace* ms = cld->metaspace_or_null();
   if (ms != NULL) {
+    size_t used_bytes, capacity_bytes;
+    ms->calculate_jfr_stats(&used_bytes, &capacity_bytes);
     if(cld->has_class_mirror_holder()) {
-      cls->_hidden_chunk_sz += ms->allocated_chunks_bytes();
-      cls->_hidden_block_sz += ms->allocated_blocks_bytes();
+      cls->_hidden_chunk_sz += capacity_bytes;
+      cls->_hidden_block_sz += used_bytes;
     } else {
-      cls->_chunk_sz = ms->allocated_chunks_bytes();
-      cls->_block_sz = ms->allocated_blocks_bytes();
+      cls->_chunk_sz = capacity_bytes;
+      cls->_block_sz = used_bytes;
     }
-    _total_chunk_sz += ms->allocated_chunks_bytes();
-    _total_block_sz += ms->allocated_blocks_bytes();
+    _total_chunk_sz += capacity_bytes;
+    _total_block_sz += used_bytes;
   }
 }
 

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

@@ -1034,7 +1034,7 @@ void G1CollectedHeap::prepare_heap_for_mutators() {
 
   // Delete metaspaces for unloaded class loaders and clean up loader_data graph
   ClassLoaderDataGraph::purge(/*at_safepoint*/true);
-  MetaspaceUtils::verify_metrics();
+  DEBUG_ONLY(MetaspaceUtils::verify();)
 
   // Prepare heap for normal collections.
   assert(num_free_regions() == 0, "we should not have added any free regions");

src/hotspot/share/gc/parallel/psParallelCompact.cpp

@@ -1058,7 +1058,7 @@ void PSParallelCompact::post_compact()
 
   // Delete metaspaces for unloaded class loaders and clean up loader_data graph
   ClassLoaderDataGraph::purge(/*at_safepoint*/true);
-  MetaspaceUtils::verify_metrics();
+  DEBUG_ONLY(MetaspaceUtils::verify();)
 
   heap->prune_scavengable_nmethods();
 

src/hotspot/share/gc/shared/collectedHeap.cpp

@@ -37,7 +37,7 @@
 #include "gc/shared/memAllocator.hpp"
 #include "logging/log.hpp"
 #include "logging/logStream.hpp"
-#include "memory/metaspace.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
 #include "oops/instanceMirrorKlass.hpp"

src/hotspot/share/gc/shared/gcVMOperations.cpp

@@ -32,6 +32,7 @@
 #include "gc/shared/genCollectedHeap.hpp"
 #include "interpreter/oopMapCache.hpp"
 #include "logging/log.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/universe.hpp"
 #include "runtime/handles.inline.hpp"

src/hotspot/share/gc/shared/gcVMOperations.hpp

@@ -28,6 +28,7 @@
 #include "gc/shared/collectedHeap.hpp"
 #include "gc/shared/genCollectedHeap.hpp"
 #include "memory/heapInspection.hpp"
+#include "memory/metaspace.hpp"
 #include "prims/jvmtiExport.hpp"
 #include "runtime/handles.hpp"
 #include "runtime/jniHandles.hpp"

src/hotspot/share/gc/shared/genCollectedHeap.cpp

@@ -58,6 +58,7 @@
 #include "gc/shared/workgroup.hpp"
 #include "memory/filemap.hpp"
 #include "memory/iterator.hpp"
+#include "memory/metaspace/metaspaceSizesSnapshot.hpp"
 #include "memory/metaspaceCounters.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
@@ -662,7 +663,7 @@ void GenCollectedHeap::do_collection(bool           full,
 
     // Delete metaspaces for unloaded class loaders and clean up loader_data graph
     ClassLoaderDataGraph::purge(/*at_safepoint*/true);
-    MetaspaceUtils::verify_metrics();
+    DEBUG_ONLY(MetaspaceUtils::verify();)
     // Resize the metaspace capacity after full collections
     MetaspaceGC::compute_new_size();
     update_full_collections_completed();

src/hotspot/share/gc/shared/generationSpec.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, 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
@@ -25,7 +25,6 @@
 #include "precompiled.hpp"
 #include "gc/shared/cardTableRS.hpp"
 #include "gc/shared/generationSpec.hpp"
-#include "memory/binaryTreeDictionary.hpp"
 #include "memory/filemap.hpp"
 #include "runtime/java.hpp"
 #include "utilities/macros.hpp"

src/hotspot/share/gc/shared/jvmFlagConstraintsGC.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, 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
@@ -262,18 +262,6 @@ JVMFlag::Error GCPauseIntervalMillisConstraintFunc(uintx value, bool verbose) {
   return JVMFlag::SUCCESS;
 }
 
-JVMFlag::Error InitialBootClassLoaderMetaspaceSizeConstraintFunc(size_t value, bool verbose) {
-  size_t aligned_max = align_down(max_uintx/2, Metaspace::reserve_alignment_words());
-  if (value > aligned_max) {
-    JVMFlag::printError(verbose,
-                        "InitialBootClassLoaderMetaspaceSize (" SIZE_FORMAT ") must be "
-                        "less than or equal to aligned maximum value (" SIZE_FORMAT ")\n",
-                        value, aligned_max);
-    return JVMFlag::VIOLATES_CONSTRAINT;
-  }
-  return JVMFlag::SUCCESS;
-}
-
 // To avoid an overflow by 'align_up(value, alignment)'.
 static JVMFlag::Error MaxSizeForAlignment(const char* name, size_t value, size_t alignment, bool verbose) {
   size_t aligned_max = ((max_uintx - alignment) & ~(alignment-1));

src/hotspot/share/gc/shared/jvmFlagConstraintsGC.hpp

@@ -56,7 +56,6 @@
                                                                \
  f(uintx,  MaxGCPauseMillisConstraintFunc)                     \
  f(uintx,  GCPauseIntervalMillisConstraintFunc)                \
- f(size_t, InitialBootClassLoaderMetaspaceSizeConstraintFunc)  \
  f(size_t, MinHeapSizeConstraintFunc)                          \
  f(size_t, InitialHeapSizeConstraintFunc)                      \
  f(size_t, MaxHeapSizeConstraintFunc)                          \

src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

@@ -71,7 +71,7 @@
 #include "gc/shenandoah/shenandoahJfrSupport.hpp"
 #endif
 
-#include "memory/metaspace.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "oops/compressedOops.inline.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/globals.hpp"
@@ -2410,7 +2410,7 @@ void ShenandoahHeap::stw_unload_classes(bool full_gc) {
   }
   // Resize and verify metaspace
   MetaspaceGC::compute_new_size();
-  MetaspaceUtils::verify_metrics();
+  DEBUG_ONLY(MetaspaceUtils::verify();)
 }
 
 // Weak roots are either pre-evacuated (final mark) or updated (final updaterefs),

src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp

@@ -35,6 +35,7 @@
 #include "gc/shenandoah/shenandoahPadding.hpp"
 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
 #include "gc/shenandoah/shenandoahUnload.hpp"
+#include "memory/metaspace.hpp"
 #include "services/memoryManager.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/stack.hpp"

src/hotspot/share/gc/shenandoah/shenandoahUnload.cpp

@@ -197,5 +197,5 @@ void ShenandoahUnload::unload() {
 
 void ShenandoahUnload::finish() {
   MetaspaceGC::compute_new_size();
-  MetaspaceUtils::verify_metrics();
+  DEBUG_ONLY(MetaspaceUtils::verify();)
 }

src/hotspot/share/gc/z/zCollectedHeap.cpp

@@ -35,6 +35,7 @@
 #include "gc/z/zServiceability.hpp"
 #include "gc/z/zStat.hpp"
 #include "gc/z/zUtils.inline.hpp"
+#include "memory/classLoaderMetaspace.hpp"
 #include "memory/iterator.hpp"
 #include "memory/universe.hpp"
 #include "utilities/align.hpp"