Merge

.hgtags

@@ -381,3 +381,5 @@ a09fe9d1e016c285307507a5793bc4fa6215e9c9 hs25-b50
 566db1b0e6efca31f181456e54c8911d0192410d hs25-b51
 c81dd5393a5e333df7cb1f6621f5897ada6522b5 jdk8-b109
 58043478c26d4e8bf48700acea5f97aba8b417d4 hs25-b52
+6209b0ed51c086d4127bac0e086c8f326d1764d7 jdk8-b110
+562a3d356de67670b4172b82aca2d30743449e04 hs25-b53

agent/src/share/classes/sun/jvm/hotspot/memory/ProtectionDomainCacheEntry.java

+/*
+ * Copyright (c) 2001, 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.memory;
+
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.oops.*;
+import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.types.*;
+
+public class ProtectionDomainCacheEntry extends VMObject {
+  private static sun.jvm.hotspot.types.OopField protectionDomainField;
+
+  static {
+    VM.registerVMInitializedObserver(new Observer() {
+        public void update(Observable o, Object data) {
+          initialize(VM.getVM().getTypeDataBase());
+        }
+      });
+  }
+
+  private static synchronized void initialize(TypeDataBase db) {
+    Type type = db.lookupType("ProtectionDomainCacheEntry");
+    protectionDomainField = type.getOopField("_literal");
+  }
+
+  public ProtectionDomainCacheEntry(Address addr) {
+    super(addr);
+  }
+
+  public Oop protectionDomain() {
+    return VM.getVM().getObjectHeap().newOop(protectionDomainField.getValue(addr));
+  }
+}

agent/src/share/classes/sun/jvm/hotspot/memory/ProtectionDomainEntry.java

 /*
- * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2013, 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
@@ -32,7 +32,7 @@ import sun.jvm.hotspot.types.*;
 
 public class ProtectionDomainEntry extends VMObject {
   private static AddressField nextField;
-  private static sun.jvm.hotspot.types.OopField protectionDomainField;
+  private static AddressField pdCacheField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
@@ -46,7 +46,7 @@ public class ProtectionDomainEntry extends VMObject {
     Type type = db.lookupType("ProtectionDomainEntry");
 
     nextField = type.getAddressField("_next");
-    protectionDomainField = type.getOopField("_protection_domain");
+    pdCacheField = type.getAddressField("_pd_cache");
   }
 
   public ProtectionDomainEntry(Address addr) {
@@ -54,10 +54,12 @@ public class ProtectionDomainEntry extends VMObject {
   }
 
   public ProtectionDomainEntry next() {
-    return (ProtectionDomainEntry) VMObjectFactory.newObject(ProtectionDomainEntry.class, addr);
+    return (ProtectionDomainEntry) VMObjectFactory.newObject(ProtectionDomainEntry.class, nextField.getValue(addr));
   }
 
   public Oop protectionDomain() {
-    return VM.getVM().getObjectHeap().newOop(protectionDomainField.getValue(addr));
+    ProtectionDomainCacheEntry pd_cache = (ProtectionDomainCacheEntry)
+      VMObjectFactory.newObject(ProtectionDomainCacheEntry.class, pdCacheField.getValue(addr));
+    return pd_cache.protectionDomain();
   }
 }

make/hotspot_version

@@ -35,7 +35,7 @@ HOTSPOT_VM_COPYRIGHT=Copyright 2013
 
 HS_MAJOR_VER=25
 HS_MINOR_VER=0
-HS_BUILD_NUMBER=53
+HS_BUILD_NUMBER=54
 
 JDK_MAJOR_VER=1
 JDK_MINOR_VER=8

src/cpu/sparc/vm/c1_Runtime1_sparc.cpp

@@ -37,6 +37,9 @@
 #include "runtime/vframeArray.hpp"
 #include "utilities/macros.hpp"
 #include "vmreg_sparc.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#endif
 
 // Implementation of StubAssembler
 
@@ -912,7 +915,7 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         Register tmp2 = G3_scratch;
         jbyte* byte_map_base = ((CardTableModRefBS*)bs)->byte_map_base;
 
-        Label not_already_dirty, restart, refill;
+        Label not_already_dirty, restart, refill, young_card;
 
 #ifdef _LP64
         __ srlx(addr, CardTableModRefBS::card_shift, addr);
@@ -924,9 +927,15 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         __ set(rs, cardtable);         // cardtable := <card table base>
         __ ldub(addr, cardtable, tmp); // tmp := [addr + cardtable]
 
+        __ cmp_and_br_short(tmp, G1SATBCardTableModRefBS::g1_young_card_val(), Assembler::equal, Assembler::pt, young_card);
+
+        __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+        __ ldub(addr, cardtable, tmp); // tmp := [addr + cardtable]
+
         assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
         __ cmp_and_br_short(tmp, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
+        __ bind(young_card);
         // We didn't take the branch, so we're already dirty: return.
         // Use return-from-leaf
         __ retl();

src/cpu/sparc/vm/macroAssembler_sparc.cpp

@@ -3752,7 +3752,7 @@ static void generate_dirty_card_log_enqueue(jbyte* byte_map_base) {
 #define __ masm.
   address start = __ pc();
 
-  Label not_already_dirty, restart, refill;
+  Label not_already_dirty, restart, refill, young_card;
 
 #ifdef _LP64
   __ srlx(O0, CardTableModRefBS::card_shift, O0);
@@ -3763,9 +3763,15 @@ static void generate_dirty_card_log_enqueue(jbyte* byte_map_base) {
   __ set(addrlit, O1); // O1 := <card table base>
   __ ldub(O0, O1, O2); // O2 := [O0 + O1]
 
+  __ cmp_and_br_short(O2, G1SATBCardTableModRefBS::g1_young_card_val(), Assembler::equal, Assembler::pt, young_card);
+
+  __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+  __ ldub(O0, O1, O2); // O2 := [O0 + O1]
+
   assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
   __ cmp_and_br_short(O2, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
+  __ bind(young_card);
   // We didn't take the branch, so we're already dirty: return.
   // Use return-from-leaf
   __ retl();

src/cpu/x86/vm/c1_Runtime1_x86.cpp

@@ -38,6 +38,9 @@
 #include "runtime/vframeArray.hpp"
 #include "utilities/macros.hpp"
 #include "vmreg_x86.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#endif
 
 
 // Implementation of StubAssembler
@@ -1753,13 +1756,17 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         __ leal(card_addr, __ as_Address(ArrayAddress(cardtable, index)));
 #endif
 
-        __ cmpb(Address(card_addr, 0), 0);
+        __ cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
+        __ jcc(Assembler::equal, done);
+
+        __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+        __ cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
         __ jcc(Assembler::equal, done);
 
         // storing region crossing non-NULL, card is clean.
         // dirty card and log.
 
-        __ movb(Address(card_addr, 0), 0);
+        __ movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
         __ cmpl(queue_index, 0);
         __ jcc(Assembler::equal, runtime);

src/cpu/x86/vm/macroAssembler_x86.cpp

@@ -3389,13 +3389,18 @@ void MacroAssembler::g1_write_barrier_post(Register store_addr,
   const Register card_addr = tmp;
   lea(card_addr, as_Address(ArrayAddress(cardtable, index)));
 #endif
-  cmpb(Address(card_addr, 0), 0);
+  cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
   jcc(Assembler::equal, done);
 
+  membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+  cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
+  jcc(Assembler::equal, done);
+
+
   // storing a region crossing, non-NULL oop, card is clean.
   // dirty card and log.
 
-  movb(Address(card_addr, 0), 0);
+  movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
   cmpl(queue_index, 0);
   jcc(Assembler::equal, runtime);

src/os/linux/vm/globals_linux.hpp

@@ -53,7 +53,7 @@
 // Defines Linux-specific default values. The flags are available on all
 // platforms, but they may have different default values on other platforms.
 //
-define_pd_global(bool, UseLargePages, true);
+define_pd_global(bool, UseLargePages, false);
 define_pd_global(bool, UseLargePagesIndividualAllocation, false);
 define_pd_global(bool, UseOSErrorReporting, false);
 define_pd_global(bool, UseThreadPriorities, true) ;

src/os/linux/vm/os_linux.cpp

@@ -3361,13 +3361,15 @@ bool os::Linux::setup_large_page_type(size_t page_size) {
   if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
       FLAG_IS_DEFAULT(UseSHM) &&
       FLAG_IS_DEFAULT(UseTransparentHugePages)) {
-    // If UseLargePages is specified on the command line try all methods,
-    // if it's default, then try only UseTransparentHugePages.
-    if (FLAG_IS_DEFAULT(UseLargePages)) {
-      UseTransparentHugePages = true;
-    } else {
-      UseHugeTLBFS = UseTransparentHugePages = UseSHM = true;
-    }
+
+    // The type of large pages has not been specified by the user.
+
+    // Try UseHugeTLBFS and then UseSHM.
+    UseHugeTLBFS = UseSHM = true;
+
+    // Don't try UseTransparentHugePages since there are known
+    // performance issues with it turned on. This might change in the future.
+    UseTransparentHugePages = false;
   }
 
   if (UseTransparentHugePages) {
@@ -3393,9 +3395,19 @@ bool os::Linux::setup_large_page_type(size_t page_size) {
 }
 
 void os::large_page_init() {
-  if (!UseLargePages) {
-    UseHugeTLBFS = false;
+  if (!UseLargePages &&
+      !UseTransparentHugePages &&
+      !UseHugeTLBFS &&
+      !UseSHM) {
+    // Not using large pages.
+    return;
+  }
+
+  if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
+    // The user explicitly turned off large pages.
+    // Ignore the rest of the large pages flags.
     UseTransparentHugePages = false;
+    UseHugeTLBFS = false;
     UseSHM = false;
     return;
   }

src/share/vm/classfile/dictionary.cpp

 /*
- * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2013, 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
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "classfile/dictionary.hpp"
 #include "classfile/systemDictionary.hpp"
+#include "memory/iterator.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
 #include "utilities/hashtable.inline.hpp"
@@ -38,17 +39,21 @@ Dictionary::Dictionary(int table_size)
   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry)) {
   _current_class_index = 0;
   _current_class_entry = NULL;
+  _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };
 
 
-
 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
                        int number_of_entries)
   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry), t, number_of_entries) {
   _current_class_index = 0;
   _current_class_entry = NULL;
+  _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };
 
+ProtectionDomainCacheEntry* Dictionary::cache_get(oop protection_domain) {
+  return _pd_cache_table->get(protection_domain);
+}
 
 DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
                                        ClassLoaderData* loader_data) {
@@ -105,11 +110,12 @@ bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
 }
 
 
-void DictionaryEntry::add_protection_domain(oop protection_domain) {
+void DictionaryEntry::add_protection_domain(Dictionary* dict, oop protection_domain) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   if (!contains_protection_domain(protection_domain)) {
+    ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
     ProtectionDomainEntry* new_head =
-                new ProtectionDomainEntry(protection_domain, _pd_set);
+                new ProtectionDomainEntry(entry, _pd_set);
     // Warning: Preserve store ordering.  The SystemDictionary is read
     //          without locks.  The new ProtectionDomainEntry must be
     //          complete before other threads can be allowed to see it
@@ -193,7 +199,10 @@ bool Dictionary::do_unloading() {
 
 
 void Dictionary::always_strong_oops_do(OopClosure* blk) {
-  // Follow all system classes and temporary placeholders in dictionary
+  // Follow all system classes and temporary placeholders in dictionary; only
+  // protection domain oops contain references into the heap. In a first
+  // pass over the system dictionary determine which need to be treated as
+  // strongly reachable and mark them as such.
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry *probe = bucket(index);
                           probe != NULL;
@@ -201,10 +210,13 @@ void Dictionary::always_strong_oops_do(OopClosure* blk) {
       Klass* e = probe->klass();
       ClassLoaderData* loader_data = probe->loader_data();
       if (is_strongly_reachable(loader_data, e)) {
-        probe->protection_domain_set_oops_do(blk);
+        probe->set_strongly_reachable();
       }
     }
   }
+  // Then iterate over the protection domain cache to apply the closure on the
+  // previously marked ones.
+  _pd_cache_table->always_strong_oops_do(blk);
 }
 
 
@@ -266,18 +278,12 @@ void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
   }
 }
 
-
 void Dictionary::oops_do(OopClosure* f) {
-  for (int index = 0; index < table_size(); index++) {
-    for (DictionaryEntry* probe = bucket(index);
-                          probe != NULL;
-                          probe = probe->next()) {
-      probe->protection_domain_set_oops_do(f);
-    }
-  }
+  // Only the protection domain oops contain references into the heap. Iterate
+  // over all of them.
+  _pd_cache_table->oops_do(f);
 }
 
-
 void Dictionary::methods_do(void f(Method*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
@@ -292,6 +298,11 @@ void Dictionary::methods_do(void f(Method*)) {
   }
 }
 
+void Dictionary::unlink(BoolObjectClosure* is_alive) {
+  // Only the protection domain cache table may contain references to the heap
+  // that need to be unlinked.
+  _pd_cache_table->unlink(is_alive);
+}
 
 Klass* Dictionary::try_get_next_class() {
   while (true) {
@@ -306,7 +317,6 @@ Klass* Dictionary::try_get_next_class() {
   // never reached
 }
 
-
 // Add a loaded class to the system dictionary.
 // Readers of the SystemDictionary aren't always locked, so _buckets
 // is volatile. The store of the next field in the constructor is
@@ -396,7 +406,7 @@ void Dictionary::add_protection_domain(int index, unsigned int hash,
   assert(protection_domain() != NULL,
          "real protection domain should be present");
 
-  entry->add_protection_domain(protection_domain());
+  entry->add_protection_domain(this, protection_domain());
 
   assert(entry->contains_protection_domain(protection_domain()),
          "now protection domain should be present");
@@ -446,6 +456,146 @@ void Dictionary::reorder_dictionary() {
   }
 }
 
+ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
+  : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
+{
+}
+
+void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
+  assert(SafepointSynchronize::is_at_safepoint(), "must be");
+  for (int i = 0; i < table_size(); ++i) {
+    ProtectionDomainCacheEntry** p = bucket_addr(i);
+    ProtectionDomainCacheEntry* entry = bucket(i);
+    while (entry != NULL) {
+      if (is_alive->do_object_b(entry->literal())) {
+        p = entry->next_addr();
+      } else {
+        *p = entry->next();
+        free_entry(entry);
+      }
+      entry = *p;
+    }
+  }
+}
+
+void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->oops_do(f);
+    }
+  }
+}
+
+uint ProtectionDomainCacheTable::bucket_size() {
+  return sizeof(ProtectionDomainCacheEntry);
+}
+
+#ifndef PRODUCT
+void ProtectionDomainCacheTable::print() {
+  tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
+                table_size(), number_of_entries());
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->print();
+    }
+  }
+}
+
+void ProtectionDomainCacheEntry::print() {
+  tty->print_cr("entry "PTR_FORMAT" value "PTR_FORMAT" strongly_reachable %d next "PTR_FORMAT,
+                this, (void*)literal(), _strongly_reachable, next());
+}
+#endif
+
+void ProtectionDomainCacheTable::verify() {
+  int element_count = 0;
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->verify();
+      element_count++;
+    }
+  }
+  guarantee(number_of_entries() == element_count,
+            "Verify of protection domain cache table failed");
+  debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
+}
+
+void ProtectionDomainCacheEntry::verify() {
+  guarantee(literal()->is_oop(), "must be an oop");
+}
+
+void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
+  // the caller marked the protection domain cache entries that we need to apply
+  // the closure on. Only process them.
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      if (probe->is_strongly_reachable()) {
+        probe->reset_strongly_reachable();
+        probe->oops_do(f);
+      }
+    }
+  }
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(oop protection_domain) {
+  unsigned int hash = compute_hash(protection_domain);
+  int index = hash_to_index(hash);
+
+  ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
+  if (entry == NULL) {
+    entry = add_entry(index, hash, protection_domain);
+  }
+  return entry;
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, oop protection_domain) {
+  for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
+    if (e->protection_domain() == protection_domain) {
+      return e;
+    }
+  }
+
+  return NULL;
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, oop protection_domain) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  assert(index == index_for(protection_domain), "incorrect index?");
+  assert(find_entry(index, protection_domain) == NULL, "no double entry");
+
+  ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
+  Hashtable<oop, mtClass>::add_entry(index, p);
+  return p;
+}
+
+void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
+  unsigned int hash = compute_hash(to_delete->protection_domain());
+  int index = hash_to_index(hash);
+
+  ProtectionDomainCacheEntry** p = bucket_addr(index);
+  ProtectionDomainCacheEntry* entry = bucket(index);
+  while (true) {
+    assert(entry != NULL, "sanity");
+
+    if (entry == to_delete) {
+      *p = entry->next();
+      Hashtable<oop, mtClass>::free_entry(entry);
+      break;
+    } else {
+      p = entry->next_addr();
+      entry = *p;
+    }
+  }
+}
+
 SymbolPropertyTable::SymbolPropertyTable(int table_size)
   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
 {
@@ -532,11 +682,13 @@ void Dictionary::print() {
       tty->cr();
     }
   }
+  tty->cr();
+  _pd_cache_table->print();
+  tty->cr();
 }
 
 #endif
 
-
 void Dictionary::verify() {
   guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
 
@@ -563,5 +715,7 @@ void Dictionary::verify() {
   guarantee(number_of_entries() == element_count,
             "Verify of system dictionary failed");
   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
+
+  _pd_cache_table->verify();
 }
 

src/share/vm/classfile/dictionary.hpp

@@ -27,11 +27,14 @@
 
 #include "classfile/systemDictionary.hpp"
 #include "oops/instanceKlass.hpp"
-#include "oops/oop.hpp"
+#include "oops/oop.inline.hpp"
 #include "utilities/hashtable.hpp"
 
 class DictionaryEntry;
 class PSPromotionManager;
+class ProtectionDomainCacheTable;
+class ProtectionDomainCacheEntry;
+class BoolObjectClosure;
 
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // The data structure for the system dictionary (and the shared system
@@ -45,6 +48,8 @@ private:
   // pointer to the current hash table entry.
   static DictionaryEntry*       _current_class_entry;
 
+  ProtectionDomainCacheTable*   _pd_cache_table;
+
   DictionaryEntry* get_entry(int index, unsigned int hash,
                              Symbol* name, ClassLoaderData* loader_data);
 
@@ -93,6 +98,7 @@ public:
 
   void methods_do(void f(Method*));
 
+  void unlink(BoolObjectClosure* is_alive);
 
   // Classes loaded by the bootstrap loader are always strongly reachable.
   // If we're not doing class unloading, all classes are strongly reachable.
@@ -118,6 +124,7 @@ public:
   // Sharing support
   void reorder_dictionary();
 
+  ProtectionDomainCacheEntry* cache_get(oop protection_domain);
 
 #ifndef PRODUCT
   void print();
@@ -126,21 +133,112 @@ public:
 };
 
 // The following classes can be in dictionary.cpp, but we need these
-// to be in header file so that SA's vmStructs can access.
+// to be in header file so that SA's vmStructs can access them.
+class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> {
+  friend class VMStructs;
+ private:
+  // Flag indicating whether this protection domain entry is strongly reachable.
+  // Used during iterating over the system dictionary to remember oops that need
+  // to be updated.
+  bool _strongly_reachable;
+ public:
+  oop protection_domain() { return literal(); }
+
+  void init() {
+    _strongly_reachable = false;
+  }
+
+  ProtectionDomainCacheEntry* next() {
+    return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next();
+  }
+
+  ProtectionDomainCacheEntry** next_addr() {
+    return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr();
+  }
+
+  void oops_do(OopClosure* f) {
+    f->do_oop(literal_addr());
+  }
+
+  void set_strongly_reachable()   { _strongly_reachable = true; }
+  bool is_strongly_reachable()    { return _strongly_reachable; }
+  void reset_strongly_reachable() { _strongly_reachable = false; }
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
+// The ProtectionDomainCacheTable contains all protection domain oops. The system
+// dictionary entries reference its entries instead of having references to oops
+// directly.
+// This is used to speed up system dictionary iteration: the oops in the
+// protection domain are the only ones referring the Java heap. So when there is
+// need to update these, instead of going over every entry of the system dictionary,
+// we only need to iterate over this set.
+// The amount of different protection domains used is typically magnitudes smaller
+// than the number of system dictionary entries (loaded classes).
+class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> {
+  friend class VMStructs;
+private:
+  ProtectionDomainCacheEntry* bucket(int i) {
+    return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i);
+  }
+
+  // The following method is not MT-safe and must be done under lock.
+  ProtectionDomainCacheEntry** bucket_addr(int i) {
+    return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i);
+  }
+
+  ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) {
+    ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain);
+    entry->init();
+    return entry;
+  }
+
+  static unsigned int compute_hash(oop protection_domain) {
+    return (unsigned int)(protection_domain->identity_hash());
+  }
+
+  int index_for(oop protection_domain) {
+    return hash_to_index(compute_hash(protection_domain));
+  }
+
+  ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);
+  ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);
+
+public:
+
+  ProtectionDomainCacheTable(int table_size);
+
+  ProtectionDomainCacheEntry* get(oop protection_domain);
+  void free(ProtectionDomainCacheEntry* entry);
+
+  void unlink(BoolObjectClosure* cl);
+
+  // GC support
+  void oops_do(OopClosure* f);
+  void always_strong_oops_do(OopClosure* f);
+
+  static uint bucket_size();
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
 
 class ProtectionDomainEntry :public CHeapObj<mtClass> {
   friend class VMStructs;
  public:
   ProtectionDomainEntry* _next;
-  oop                    _protection_domain;
+  ProtectionDomainCacheEntry* _pd_cache;
 
-  ProtectionDomainEntry(oop protection_domain, ProtectionDomainEntry* next) {
-    _protection_domain = protection_domain;
-    _next              = next;
+  ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
+    _pd_cache = pd_cache;
+    _next     = next;
   }
 
   ProtectionDomainEntry* next() { return _next; }
-  oop protection_domain() { return _protection_domain; }
+  oop protection_domain() { return _pd_cache->protection_domain(); }
 };
 
 // An entry in the system dictionary, this describes a class as
@@ -151,6 +249,24 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
  private:
   // Contains the set of approved protection domains that can access
   // this system dictionary entry.
+  //
+  // This protection domain set is a set of tuples:
+  //
+  // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
+  //
+  // [Note that C.protection_domain(), which is stored in the java.lang.Class
+  // mirror of C, is NOT the same as PD]
+  //
+  // If such an entry (C, ICL, PD) exists in the table, it means that
+  // it is okay for a class Foo to reference C, where
+  //
+  //    Foo.protection_domain() == PD, and
+  //    Foo's defining class loader == ICL
+  //
+  // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
+  // It is essentially a cache to avoid repeated Java up-calls to
+  // ClassLoader.checkPackageAccess().
+  //
   ProtectionDomainEntry* _pd_set;
   ClassLoaderData*       _loader_data;
 
@@ -158,7 +274,7 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
   // Tells whether a protection is in the approved set.
   bool contains_protection_domain(oop protection_domain) const;
   // Adds a protection domain to the approved set.
-  void add_protection_domain(oop protection_domain);
+  void add_protection_domain(Dictionary* dict, oop protection_domain);
 
   Klass* klass() const { return (Klass*)literal(); }
   Klass** klass_addr() { return (Klass**)literal_addr(); }
@@ -189,12 +305,11 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
          : contains_protection_domain(protection_domain());
   }
 
-
-  void protection_domain_set_oops_do(OopClosure* f) {
+  void set_strongly_reachable() {
     for (ProtectionDomainEntry* current = _pd_set;
                                 current != NULL;
                                 current = current->_next) {
-      f->do_oop(&(current->_protection_domain));
+      current->_pd_cache->set_strongly_reachable();
     }
   }
 
@@ -202,7 +317,7 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
     for (ProtectionDomainEntry* current = _pd_set;
                                 current != NULL;
                                 current = current->_next) {
-      current->_protection_domain->verify();
+      current->_pd_cache->protection_domain()->verify();
     }
   }
 

src/share/vm/classfile/systemDictionary.cpp

@@ -1697,6 +1697,24 @@ int SystemDictionary::calculate_systemdictionary_size(int classcount) {
   return newsize;
 }
 
+#ifdef ASSERT
+class VerifySDReachableAndLiveClosure : public OopClosure {
+private:
+  BoolObjectClosure* _is_alive;
+
+  template <class T> void do_oop_work(T* p) {
+    oop obj = oopDesc::load_decode_heap_oop(p);
+    guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
+  }
+
+public:
+  VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
+
+  virtual void do_oop(oop* p)       { do_oop_work(p); }
+  virtual void do_oop(narrowOop* p) { do_oop_work(p); }
+};
+#endif
+
 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
 // Note: anonymous classes are not in the SD.
 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
@@ -1707,7 +1725,15 @@ bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
     unloading_occurred = dictionary()->do_unloading();
     constraints()->purge_loader_constraints();
     resolution_errors()->purge_resolution_errors();
-}
+  }
+  // Oops referenced by the system dictionary may get unreachable independently
+  // of the class loader (eg. cached protection domain oops). So we need to
+  // explicitly unlink them here instead of in Dictionary::do_unloading.
+  dictionary()->unlink(is_alive);
+#ifdef ASSERT
+  VerifySDReachableAndLiveClosure cl(is_alive);
+  dictionary()->oops_do(&cl);
+#endif
   return unloading_occurred;
 }
 

src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -6035,7 +6035,11 @@ void G1CollectedHeap::verify_dirty_region(HeapRegion* hr) {
   // is dirty.
   G1SATBCardTableModRefBS* ct_bs = g1_barrier_set();
   MemRegion mr(hr->bottom(), hr->pre_dummy_top());
-  ct_bs->verify_dirty_region(mr);
+  if (hr->is_young()) {
+    ct_bs->verify_g1_young_region(mr);
+  } else {
+    ct_bs->verify_dirty_region(mr);
+  }
 }
 
 void G1CollectedHeap::verify_dirty_young_list(HeapRegion* head) {

src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp

@@ -29,6 +29,7 @@
 #include "gc_implementation/g1/g1CollectedHeap.hpp"
 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "utilities/taskqueue.hpp"
 
@@ -134,7 +135,7 @@ G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
 
   MemRegion mr(start, end);
-  g1_barrier_set()->dirty(mr);
+  g1_barrier_set()->g1_mark_as_young(mr);
 }
 
 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

@@ -319,10 +319,10 @@ G1CollectorPolicy::G1CollectorPolicy() :
 }
 
 void G1CollectorPolicy::initialize_flags() {
-  set_min_alignment(HeapRegion::GrainBytes);
+  _min_alignment = HeapRegion::GrainBytes;
   size_t card_table_alignment = GenRemSet::max_alignment_constraint(rem_set_name());
   size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
-  set_max_alignment(MAX3(card_table_alignment, min_alignment(), page_size));
+  _max_alignment = MAX3(card_table_alignment, _min_alignment, page_size);
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp

@@ -70,6 +70,12 @@ bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
   if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
     return false;
   }
+
+  if  (val == g1_young_gen) {
+    // the card is for a young gen region. We don't need to keep track of all pointers into young
+    return false;
+  }
+
   // Cached bit can be installed either on a clean card or on a claimed card.
   jbyte new_val = val;
   if (val == clean_card_val()) {
@@ -85,6 +91,19 @@ bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
   return true;
 }
 
+void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
+  jbyte *const first = byte_for(mr.start());
+  jbyte *const last = byte_after(mr.last());
+
+  memset(first, g1_young_gen, last - first);
+}
+
+#ifndef PRODUCT
+void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
+  verify_region(mr, g1_young_gen,  true);
+}
+#endif
+
 G1SATBCardTableLoggingModRefBS::
 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
                                int max_covered_regions) :
@@ -97,7 +116,11 @@ G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
 void
 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
                                                      oop new_val) {
-  jbyte* byte = byte_for(field);
+  volatile jbyte* byte = byte_for(field);
+  if (*byte == g1_young_gen) {
+    return;
+  }
+  OrderAccess::storeload();
   if (*byte != dirty_card) {
     *byte = dirty_card;
     Thread* thr = Thread::current();
@@ -129,7 +152,7 @@ G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
 
 void
 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
-  jbyte* byte = byte_for(mr.start());
+  volatile jbyte* byte = byte_for(mr.start());
   jbyte* last_byte = byte_for(mr.last());
   Thread* thr = Thread::current();
   if (whole_heap) {
@@ -138,25 +161,35 @@ G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
       byte++;
     }
   } else {
-    // Enqueue if necessary.
-    if (thr->is_Java_thread()) {
-      JavaThread* jt = (JavaThread*)thr;
-      while (byte <= last_byte) {
-        if (*byte != dirty_card) {
-          *byte = dirty_card;
-          jt->dirty_card_queue().enqueue(byte);
+    // skip all consecutive young cards
+    for (; byte <= last_byte && *byte == g1_young_gen; byte++);
+
+    if (byte <= last_byte) {
+      OrderAccess::storeload();
+      // Enqueue if necessary.
+      if (thr->is_Java_thread()) {
+        JavaThread* jt = (JavaThread*)thr;
+        for (; byte <= last_byte; byte++) {
+          if (*byte == g1_young_gen) {
+            continue;
+          }
+          if (*byte != dirty_card) {
+            *byte = dirty_card;
+            jt->dirty_card_queue().enqueue(byte);
+          }
         }
-        byte++;
-      }
-    } else {
-      MutexLockerEx x(Shared_DirtyCardQ_lock,
-                      Mutex::_no_safepoint_check_flag);
-      while (byte <= last_byte) {
-        if (*byte != dirty_card) {
-          *byte = dirty_card;
-          _dcqs.shared_dirty_card_queue()->enqueue(byte);
+      } else {
+        MutexLockerEx x(Shared_DirtyCardQ_lock,
+                        Mutex::_no_safepoint_check_flag);
+        for (; byte <= last_byte; byte++) {
+          if (*byte == g1_young_gen) {
+            continue;
+          }
+          if (*byte != dirty_card) {
+            *byte = dirty_card;
+            _dcqs.shared_dirty_card_queue()->enqueue(byte);
+          }
         }
-        byte++;
       }
     }
   }

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp

@@ -38,7 +38,14 @@ class DirtyCardQueueSet;
 // snapshot-at-the-beginning marking.
 
 class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {
+protected:
+  enum G1CardValues {
+    g1_young_gen = CT_MR_BS_last_reserved << 1
+  };
+
 public:
+  static int g1_young_card_val()   { return g1_young_gen; }
+
   // Add "pre_val" to a set of objects that may have been disconnected from the
   // pre-marking object graph.
   static void enqueue(oop pre_val);
@@ -118,6 +125,9 @@ public:
       _byte_map[card_index] = val;
   }
 
+  void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
+  void g1_mark_as_young(const MemRegion& mr);
+
   bool mark_card_deferred(size_t card_index);
 
   bool is_card_deferred(size_t card_index) {

src/share/vm/gc_implementation/g1/ptrQueue.hpp

@@ -80,6 +80,10 @@ public:
 
   void reset() { if (_buf != NULL) _index = _sz; }
 
+  void enqueue(volatile void* ptr) {
+    enqueue((void*)(ptr));
+  }
+
   // Enqueues the given "obj".
   void enqueue(void* ptr) {
     if (!_active) return;

src/share/vm/gc_implementation/shared/vmGCOperations.hpp

@@ -214,9 +214,6 @@ class VM_CollectForMetadataAllocation: public VM_GC_Operation {
     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true),
       _loader_data(loader_data), _size(size), _mdtype(mdtype), _result(NULL) {
   }
-  ~VM_CollectForMetadataAllocation()  {
-    MetaspaceGC::set_expand_after_GC(false);
-  }
   virtual VMOp_Type type() const { return VMOp_CollectForMetadataAllocation; }
   virtual void doit();
   MetaWord* result() const       { return _result; }

src/share/vm/gc_interface/collectedHeap.cpp

@@ -202,12 +202,6 @@ void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
       ShouldNotReachHere(); // Unexpected use of this function
   }
 }
-MetaWord* CollectedHeap::satisfy_failed_metadata_allocation(
-                                              ClassLoaderData* loader_data,
-                                              size_t size, Metaspace::MetadataType mdtype) {
-  return collector_policy()->satisfy_failed_metadata_allocation(loader_data, size, mdtype);
-}
-
 
 void CollectedHeap::pre_initialize() {
   // Used for ReduceInitialCardMarks (when COMPILER2 is used);

src/share/vm/gc_interface/collectedHeap.hpp

@@ -475,11 +475,6 @@ class CollectedHeap : public CHeapObj<mtInternal> {
   // the context of the vm thread.
   virtual void collect_as_vm_thread(GCCause::Cause cause);
 
-  // Callback from VM_CollectForMetadataAllocation operation.
-  MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
-                                               size_t size,
-                                               Metaspace::MetadataType mdtype);
-
   // Returns the barrier set for this heap
   BarrierSet* barrier_set() { return _barrier_set; }
 

src/share/vm/memory/collectorPolicy.hpp

@@ -101,17 +101,12 @@ class CollectorPolicy : public CHeapObj<mtGC> {
   // Return maximum heap alignment that may be imposed by the policy
   static size_t compute_max_alignment();
 
-  void set_min_alignment(size_t align)         { _min_alignment = align; }
   size_t min_alignment()                       { return _min_alignment; }
-  void set_max_alignment(size_t align)         { _max_alignment = align; }
   size_t max_alignment()                       { return _max_alignment; }
 
   size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
-  void set_initial_heap_byte_size(size_t v) { _initial_heap_byte_size = v; }
   size_t max_heap_byte_size()     { return _max_heap_byte_size; }
-  void set_max_heap_byte_size(size_t v) { _max_heap_byte_size = v; }
   size_t min_heap_byte_size()     { return _min_heap_byte_size; }
-  void set_min_heap_byte_size(size_t v) { _min_heap_byte_size = v; }
 
   enum Name {
     CollectorPolicyKind,
@@ -248,12 +243,9 @@ class GenCollectorPolicy : public CollectorPolicy {
 
  public:
   // Accessors
-  size_t min_gen0_size() { return _min_gen0_size; }
-  void set_min_gen0_size(size_t v) { _min_gen0_size = v; }
+  size_t min_gen0_size()     { return _min_gen0_size; }
   size_t initial_gen0_size() { return _initial_gen0_size; }
-  void set_initial_gen0_size(size_t v) { _initial_gen0_size = v; }
-  size_t max_gen0_size() { return _max_gen0_size; }
-  void set_max_gen0_size(size_t v) { _max_gen0_size = v; }
+  size_t max_gen0_size()     { return _max_gen0_size; }
 
   virtual int number_of_generations() = 0;
 
@@ -302,12 +294,9 @@ class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
 
  public:
   // Accessors
-  size_t min_gen1_size() { return _min_gen1_size; }
-  void set_min_gen1_size(size_t v) { _min_gen1_size = v; }
+  size_t min_gen1_size()     { return _min_gen1_size; }
   size_t initial_gen1_size() { return _initial_gen1_size; }
-  void set_initial_gen1_size(size_t v) { _initial_gen1_size = v; }
-  size_t max_gen1_size() { return _max_gen1_size; }
-  void set_max_gen1_size(size_t v) { _max_gen1_size = v; }
+  size_t max_gen1_size()     { return _max_gen1_size; }
 
   // Inherited methods
   TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }

src/share/vm/memory/filemap.hpp

@@ -26,6 +26,7 @@
 #define SHARE_VM_MEMORY_FILEMAP_HPP
 
 #include "memory/metaspaceShared.hpp"
+#include "memory/metaspace.hpp"
 
 // Layout of the file:
 //  header: dump of archive instance plus versioning info, datestamp, etc.

src/share/vm/memory/metaspace.hpp

@@ -87,9 +87,10 @@ class Metaspace : public CHeapObj<mtClass> {
   friend class MetaspaceAux;
 
  public:
-  enum MetadataType {ClassType = 0,
-                     NonClassType = ClassType + 1,
-                     MetadataTypeCount = ClassType + 2
+  enum MetadataType {
+    ClassType,
+    NonClassType,
+    MetadataTypeCount
   };
   enum MetaspaceType {
     StandardMetaspaceType,
@@ -103,6 +104,9 @@ class Metaspace : public CHeapObj<mtClass> {
  private:
   void initialize(Mutex* lock, MetaspaceType type);
 
+  // Get the first chunk for a Metaspace.  Used for
+  // special cases such as the boot class loader, reflection
+  // class loader and anonymous class loader.
   Metachunk* get_initialization_chunk(MetadataType mdtype,
                                       size_t chunk_word_size,
                                       size_t chunk_bunch);
@@ -123,6 +127,9 @@ class Metaspace : public CHeapObj<mtClass> {
   static size_t _first_chunk_word_size;
   static size_t _first_class_chunk_word_size;
 
+  static size_t _commit_alignment;
+  static size_t _reserve_alignment;
+
   SpaceManager* _vsm;
   SpaceManager* vsm() const { return _vsm; }
 
@@ -191,12 +198,17 @@ class Metaspace : public CHeapObj<mtClass> {
   Metaspace(Mutex* lock, MetaspaceType type);
   ~Metaspace();
 
-  // Initialize globals for Metaspace
+  static void ergo_initialize();
   static void global_initialize();
 
   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 
+  static size_t reserve_alignment()       { return _reserve_alignment; }
+  static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
+  static size_t commit_alignment()        { return _commit_alignment; }
+  static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
+
   char*  bottom() const;
   size_t used_words_slow(MetadataType mdtype) const;
   size_t free_words_slow(MetadataType mdtype) const;
@@ -219,6 +231,9 @@ class Metaspace : public CHeapObj<mtClass> {
   static void purge(MetadataType mdtype);
   static void purge();
 
+  static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
+                                   MetadataType mdtype, TRAPS);
+
   void print_on(outputStream* st) const;
   // Debugging support
   void verify();
@@ -352,17 +367,10 @@ class MetaspaceAux : AllStatic {
 
 class MetaspaceGC : AllStatic {
 
-  // The current high-water-mark for inducing a GC.  When
-  // the capacity of all space in the virtual lists reaches this value,
-  // a GC is induced and the value is increased.  This should be changed
-  // to the space actually used for allocations to avoid affects of
-  // fragmentation losses to partially used chunks.  Size is in words.
-  static size_t _capacity_until_GC;
-
-  // After a GC is done any allocation that fails should try to expand
-  // the capacity of the Metaspaces.  This flag is set during attempts
-  // to allocate in the VMGCOperation that does the GC.
-  static bool _expand_after_GC;
+  // The current high-water-mark for inducing a GC.
+  // When committed memory of all metaspaces reaches this value,
+  // a GC is induced and the value is increased. Size is in bytes.
+  static volatile intptr_t _capacity_until_GC;
 
   // For a CMS collection, signal that a concurrent collection should
   // be started.
@@ -370,20 +378,16 @@ class MetaspaceGC : AllStatic {
 
   static uint _shrink_factor;
 
-  static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; }
-
   static size_t shrink_factor() { return _shrink_factor; }
   void set_shrink_factor(uint v) { _shrink_factor = v; }
 
  public:
 
-  static size_t capacity_until_GC() { return _capacity_until_GC; }
-  static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; }
-  static void dec_capacity_until_GC(size_t v) {
-    _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0;
-  }
-  static bool expand_after_GC()           { return _expand_after_GC; }
-  static void set_expand_after_GC(bool v) { _expand_after_GC = v; }
+  static void initialize() { _capacity_until_GC = MetaspaceSize; }
+
+  static size_t capacity_until_GC();
+  static size_t inc_capacity_until_GC(size_t v);
+  static size_t dec_capacity_until_GC(size_t v);
 
   static bool should_concurrent_collect() { return _should_concurrent_collect; }
   static void set_should_concurrent_collect(bool v) {
@@ -391,11 +395,14 @@ class MetaspaceGC : AllStatic {
   }
 
   // The amount to increase the high-water-mark (_capacity_until_GC)
-  static size_t delta_capacity_until_GC(size_t word_size);
+  static size_t delta_capacity_until_GC(size_t bytes);
+
+  // Tells if we have can expand metaspace without hitting set limits.
+  static bool can_expand(size_t words, bool is_class);
 
-  // It is expected that this will be called when the current capacity
-  // has been used and a GC should be considered.
-  static bool should_expand(VirtualSpaceList* vsl, size_t word_size);
+  // Returns amount that we can expand without hitting a GC,
+  // measured in words.
+  static size_t allowed_expansion();
 
   // Calculate the new high-water mark at which to induce
   // a GC.

src/share/vm/opto/graphKit.cpp

@@ -3713,7 +3713,8 @@ void GraphKit::g1_write_barrier_post(Node* oop_store,
   Node* no_base = __ top();
   float likely  = PROB_LIKELY(0.999);
   float unlikely  = PROB_UNLIKELY(0.999);
-  Node* zero = __ ConI(0);
+  Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
+  Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
   Node* zeroX = __ ConX(0);
 
   // Get the alias_index for raw card-mark memory
@@ -3769,8 +3770,16 @@ void GraphKit::g1_write_barrier_post(Node* oop_store,
         // load the original value of the card
         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
 
-        __ if_then(card_val, BoolTest::ne, zero); {
-          g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
+        __ if_then(card_val, BoolTest::ne, young_card); {
+          sync_kit(ideal);
+          // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
+          insert_mem_bar(Op_MemBarVolatile, oop_store);
+          __ sync_kit(this);
+
+          Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
+          __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
+            g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
+          } __ end_if();
         } __ end_if();
       } __ end_if();
     } __ end_if();

src/share/vm/runtime/arguments.cpp

@@ -2657,16 +2657,16 @@ jint Arguments::parse_each_vm_init_arg(const JavaVMInitArgs* args,
       FLAG_SET_CMDLINE(bool, BackgroundCompilation, false);
     // -Xmn for compatibility with other JVM vendors
     } else if (match_option(option, "-Xmn", &tail)) {
-      julong long_initial_eden_size = 0;
-      ArgsRange errcode = parse_memory_size(tail, &long_initial_eden_size, 1);
+      julong long_initial_young_size = 0;
+      ArgsRange errcode = parse_memory_size(tail, &long_initial_young_size, 1);
       if (errcode != arg_in_range) {
         jio_fprintf(defaultStream::error_stream(),
-                    "Invalid initial eden size: %s\n", option->optionString);
+                    "Invalid initial young generation size: %s\n", option->optionString);
         describe_range_error(errcode);
         return JNI_EINVAL;
       }
-      FLAG_SET_CMDLINE(uintx, MaxNewSize, (uintx)long_initial_eden_size);
-      FLAG_SET_CMDLINE(uintx, NewSize, (uintx)long_initial_eden_size);
+      FLAG_SET_CMDLINE(uintx, MaxNewSize, (uintx)long_initial_young_size);
+      FLAG_SET_CMDLINE(uintx, NewSize, (uintx)long_initial_young_size);
     // -Xms
     } else if (match_option(option, "-Xms", &tail)) {
       julong long_initial_heap_size = 0;
@@ -3666,6 +3666,9 @@ jint Arguments::apply_ergo() {
   assert(verify_serial_gc_flags(), "SerialGC unset");
 #endif // INCLUDE_ALL_GCS
 
+  // Initialize Metaspace flags and alignments.
+  Metaspace::ergo_initialize();
+
   // Set bytecode rewriting flags
   set_bytecode_flags();
 

src/share/vm/runtime/virtualspace.cpp

@@ -368,8 +368,15 @@ VirtualSpace::VirtualSpace() {
 
 
 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
+  const size_t max_commit_granularity = os::page_size_for_region(rs.size(), rs.size(), 1);
+  return initialize_with_granularity(rs, committed_size, max_commit_granularity);
+}
+
+bool VirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t committed_size, size_t max_commit_granularity) {
   if(!rs.is_reserved()) return false;  // allocation failed.
   assert(_low_boundary == NULL, "VirtualSpace already initialized");
+  assert(max_commit_granularity > 0, "Granularity must be non-zero.");
+
   _low_boundary  = rs.base();
   _high_boundary = low_boundary() + rs.size();
 
@@ -390,7 +397,7 @@ bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
   // No attempt is made to force large page alignment at the very top and
   // bottom of the space if they are not aligned so already.
   _lower_alignment  = os::vm_page_size();
-  _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1);
+  _middle_alignment = max_commit_granularity;
   _upper_alignment  = os::vm_page_size();
 
   // End of each region
@@ -966,17 +973,52 @@ void TestReservedSpace_test() {
 
 
 class TestVirtualSpace : AllStatic {
+  enum TestLargePages {
+    Default,
+    Disable,
+    Reserve,
+    Commit
+  };
+
+  static ReservedSpace reserve_memory(size_t reserve_size_aligned, TestLargePages mode) {
+    switch(mode) {
+    default:
+    case Default:
+    case Reserve:
+      return ReservedSpace(reserve_size_aligned);
+    case Disable:
+    case Commit:
+      return ReservedSpace(reserve_size_aligned,
+                           os::vm_allocation_granularity(),
+                           /* large */ false, /* exec */ false);
+    }
+  }
+
+  static bool initialize_virtual_space(VirtualSpace& vs, ReservedSpace rs, TestLargePages mode) {
+    switch(mode) {
+    default:
+    case Default:
+    case Reserve:
+      return vs.initialize(rs, 0);
+    case Disable:
+      return vs.initialize_with_granularity(rs, 0, os::vm_page_size());
+    case Commit:
+      return vs.initialize_with_granularity(rs, 0, os::page_size_for_region(rs.size(), rs.size(), 1));
+    }
+  }
+
  public:
-  static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size) {
+  static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size,
+                                                        TestLargePages mode = Default) {
     size_t granularity = os::vm_allocation_granularity();
     size_t reserve_size_aligned = align_size_up(reserve_size, granularity);
 
-    ReservedSpace reserved(reserve_size_aligned);
+    ReservedSpace reserved = reserve_memory(reserve_size_aligned, mode);
 
     assert(reserved.is_reserved(), "Must be");
 
     VirtualSpace vs;
-    bool initialized = vs.initialize(reserved, 0);
+    bool initialized = initialize_virtual_space(vs, reserved, mode);
     assert(initialized, "Failed to initialize VirtualSpace");
 
     vs.expand_by(commit_size, false);
@@ -986,7 +1028,10 @@ class TestVirtualSpace : AllStatic {
     } else {
       assert_ge(vs.actual_committed_size(), commit_size);
       // Approximate the commit granularity.
-      size_t commit_granularity = UseLargePages ? os::large_page_size() : os::vm_page_size();
+      // Make sure that we don't commit using large pages
+      // if large pages has been disabled for this VirtualSpace.
+      size_t commit_granularity = (mode == Disable || !UseLargePages) ?
+                                   os::vm_page_size() : os::large_page_size();
       assert_lt(vs.actual_committed_size(), commit_size + commit_granularity);
     }
 
@@ -1042,9 +1087,40 @@ class TestVirtualSpace : AllStatic {
     test_virtual_space_actual_committed_space(10 * M, 10 * M);
   }
 
+  static void test_virtual_space_disable_large_pages() {
+    if (!UseLargePages) {
+      return;
+    }
+    // These test cases verify that if we force VirtualSpace to disable large pages
+    test_virtual_space_actual_committed_space(10 * M, 0, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Disable);
+
+    test_virtual_space_actual_committed_space(10 * M, 0, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Reserve);
+
+    test_virtual_space_actual_committed_space(10 * M, 0, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Commit);
+  }
+
   static void test_virtual_space() {
     test_virtual_space_actual_committed_space();
     test_virtual_space_actual_committed_space_one_large_page();
+    test_virtual_space_disable_large_pages();
   }
 };
 

src/share/vm/runtime/virtualspace.hpp

@@ -178,6 +178,7 @@ class VirtualSpace VALUE_OBJ_CLASS_SPEC {
  public:
   // Initialization
   VirtualSpace();
+  bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
   bool initialize(ReservedSpace rs, size_t committed_byte_size);
 
   // Destruction

src/share/vm/runtime/vmStructs.cpp

@@ -716,11 +716,17 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   nonstatic_field(PlaceholderEntry,            _loader_data,                                  ClassLoaderData*)                      \
                                                                                                                                      \
   /**************************/                                                                                                       \
-  /* ProctectionDomainEntry */                                                                                                       \
+  /* ProtectionDomainEntry  */                                                                                                       \
   /**************************/                                                                                                       \
                                                                                                                                      \
   nonstatic_field(ProtectionDomainEntry,       _next,                                         ProtectionDomainEntry*)                \
-  nonstatic_field(ProtectionDomainEntry,       _protection_domain,                            oop)                                   \
+  nonstatic_field(ProtectionDomainEntry,       _pd_cache,                                     ProtectionDomainCacheEntry*)           \
+                                                                                                                                     \
+  /*******************************/                                                                                                  \
+  /* ProtectionDomainCacheEntry  */                                                                                                  \
+  /*******************************/                                                                                                  \
+                                                                                                                                     \
+  nonstatic_field(ProtectionDomainCacheEntry,  _literal,                                      oop)                                   \
                                                                                                                                      \
   /*************************/                                                                                                        \
   /* LoaderConstraintEntry */                                                                                                        \
@@ -1563,6 +1569,7 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   declare_toplevel_type(SystemDictionary)                                 \
   declare_toplevel_type(vmSymbols)                                        \
   declare_toplevel_type(ProtectionDomainEntry)                            \
+  declare_toplevel_type(ProtectionDomainCacheEntry)                       \
                                                                           \
   declare_toplevel_type(GenericGrowableArray)                             \
   declare_toplevel_type(GrowableArray<int>)                               \

src/share/vm/services/memoryService.hpp

@@ -148,6 +148,12 @@ public:
   static void track_code_cache_memory_usage() {
     track_memory_pool_usage(_code_heap_pool);
   }
+  static void track_metaspace_memory_usage() {
+    track_memory_pool_usage(_metaspace_pool);
+  }
+  static void track_compressed_class_memory_usage() {
+    track_memory_pool_usage(_compressed_class_pool);
+  }
   static void track_memory_pool_usage(MemoryPool* pool);
 
   static void gc_begin(bool fullGC, bool recordGCBeginTime,

src/share/vm/utilities/globalDefinitions.hpp

@@ -326,12 +326,15 @@ typedef jlong  s8;
 
 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 
+// Default ProtectionDomainCacheSize values
+
+const int defaultProtectionDomainCacheSize = NOT_LP64(137) LP64_ONLY(2017);
 
 //----------------------------------------------------------------------------------------------------
 // Default and minimum StringTableSize values
 
 const int defaultStringTableSize = NOT_LP64(1009) LP64_ONLY(60013);
-const int minimumStringTableSize=1009;
+const int minimumStringTableSize = 1009;
 
 const int defaultSymbolTableSize = 20011;
 const int minimumSymbolTableSize = 1009;

test/runtime/memory/LargePages/TestLargePagesFlags.java

+/*
+ * Copyright (c) 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test TestLargePagesFlags
+ * @summary Tests how large pages are choosen depending on the given large pages flag combinations.
+ * @library /testlibrary
+ * @run main TestLargePagesFlags
+ */
+
+import com.oracle.java.testlibrary.OutputAnalyzer;
+import com.oracle.java.testlibrary.Platform;
+import com.oracle.java.testlibrary.ProcessTools;
+import java.util.ArrayList;
+
+public class TestLargePagesFlags {
+
+  public static void main(String [] args) throws Exception {
+    if (!Platform.isLinux()) {
+      System.out.println("Skipping. TestLargePagesFlags has only been implemented for Linux.");
+      return;
+    }
+
+    testUseTransparentHugePages();
+    testUseHugeTLBFS();
+    testUseSHM();
+    testCombinations();
+  }
+
+  public static void testUseTransparentHugePages() throws Exception {
+    if (!canUse(UseTransparentHugePages(true))) {
+      System.out.println("Skipping testUseTransparentHugePages");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseTransparentHugePages.
+    new FlagTester()
+      .use(UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Don't turn on UseTransparentHugePages
+    // unless the user explicitly asks for them.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseTransparentHugePages(false));
+  }
+
+  public static void testUseHugeTLBFS() throws Exception {
+    if (!canUse(UseHugeTLBFS(true))) {
+      System.out.println("Skipping testUseHugeTLBFS");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseHugeTLBFS.
+    new FlagTester()
+      .use(UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Using UseLargePages will default to UseHugeTLBFS large pages.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+  }
+
+  public static void testUseSHM() throws Exception {
+    if (!canUse(UseSHM(true))) {
+      System.out.println("Skipping testUseSHM");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseSHM(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseSHM.
+    new FlagTester()
+      .use(UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true)) ;
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true)) ;
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseSHM(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Setting UseLargePages can allow the system to choose
+    // UseHugeTLBFS instead of UseSHM, but never UseTransparentHugePages.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false));
+  }
+
+  public static void testCombinations() throws Exception {
+    if (!canUse(UseSHM(true)) || !canUse(UseHugeTLBFS(true))) {
+      System.out.println("Skipping testUseHugeTLBFSAndUseSHMCombination");
+      return;
+    }
+
+    // UseHugeTLBFS takes precedence over SHM.
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(false))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+
+    if (!canUse(UseTransparentHugePages(true))) {
+      return;
+    }
+
+    // UseTransparentHugePages takes precedence.
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseTransparentHugePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+  }
+
+  private static class FlagTester {
+    private Flag [] useFlags;
+
+    public FlagTester use(Flag... useFlags) {
+      this.useFlags = useFlags;
+      return this;
+    }
+
+    public void expect(Flag... expectedFlags) throws Exception {
+      if (useFlags == null) {
+        throw new IllegalStateException("Must run use() before expect()");
+      }
+
+      OutputAnalyzer output = executeNewJVM(useFlags);
+
+      for (Flag flag : expectedFlags) {
+        System.out.println("Looking for: " + flag.flagString());
+        String strValue = output.firstMatch(".* " + flag.name() +  " .* :?= (\\S+).*", 1);
+
+        if (strValue == null) {
+          throw new RuntimeException("Flag " + flag.name() + " couldn't be found");
+        }
+
+        if (!flag.value().equals(strValue)) {
+          throw new RuntimeException("Wrong value for: " + flag.name()
+                                     + " expected: " + flag.value()
+                                     + " got: " + strValue);
+        }
+      }
+
+      output.shouldHaveExitValue(0);
+    }
+  }
+
+  private static OutputAnalyzer executeNewJVM(Flag... flags) throws Exception {
+    ArrayList<String> args = new ArrayList<>();
+    for (Flag flag : flags) {
+      args.add(flag.flagString());
+    }
+    args.add("-XX:+PrintFlagsFinal");
+    args.add("-version");
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args.toArray(new String[args.size()]));
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    return output;
+  }
+
+  private static boolean canUse(Flag flag) {
+    try {
+      new FlagTester().use(flag).expect(flag);
+    } catch (Exception e) {
+      return false;
+    }
+
+    return true;
+  }
+
+  private static Flag UseLargePages(boolean value) {
+    return new BooleanFlag("UseLargePages", value);
+  }
+
+  private static Flag UseTransparentHugePages(boolean value) {
+    return new BooleanFlag("UseTransparentHugePages", value);
+  }
+
+  private static Flag UseHugeTLBFS(boolean value) {
+    return new BooleanFlag("UseHugeTLBFS", value);
+  }
+
+  private static Flag UseSHM(boolean value) {
+    return new BooleanFlag("UseSHM", value);
+  }
+
+  private static class BooleanFlag implements Flag {
+    private String name;
+    private boolean value;
+
+    BooleanFlag(String name, boolean value) {
+      this.name = name;
+      this.value = value;
+    }
+
+    public String flagString() {
+      return "-XX:" + (value ? "+" : "-") + name;
+    }
+
+    public String name() {
+      return name;
+    }
+
+    public String value() {
+      return Boolean.toString(value);
+    }
+  }
+
+  private static interface Flag {
+    public String flagString();
+    public String name();
+    public String value();
+  }
+}