8150752: Share Class Data

Reviewed-by: acorn, hseigel, mschoene

src/share/vm/classfile/dictionary.cpp

 /*
- * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, 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 "classfile/systemDictionaryShared.hpp"
 #include "memory/iterator.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
@@ -36,9 +37,16 @@ PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 DictionaryEntry*  Dictionary::_current_class_entry = NULL;
 int               Dictionary::_current_class_index =    0;
 
+size_t Dictionary::entry_size() {
+  if (DumpSharedSpaces) {
+    return SystemDictionaryShared::dictionary_entry_size();
+  } else {
+    return sizeof(DictionaryEntry);
+  }
+}
 
 Dictionary::Dictionary(int table_size)
-  : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry)) {
+  : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size()) {
   _current_class_index = 0;
   _current_class_entry = NULL;
   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
@@ -47,7 +55,7 @@ Dictionary::Dictionary(int table_size)
 
 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
                        int number_of_entries)
-  : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry), t, number_of_entries) {
+  : TwoOopHashtable<Klass*, mtClass>(table_size, (int)entry_size(), t, number_of_entries) {
   _current_class_index = 0;
   _current_class_entry = NULL;
   _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
@@ -63,6 +71,9 @@ DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
   entry->set_loader_data(loader_data);
   entry->set_pd_set(NULL);
   assert(klass->oop_is_instance(), "Must be");
+  if (DumpSharedSpaces) {
+    SystemDictionaryShared::init_shared_dictionary_entry(klass, entry);
+  }
   return entry;
 }
 

src/share/vm/classfile/dictionary.hpp

 /*
- * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, 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
@@ -53,6 +53,7 @@ private:
   DictionaryEntry* get_entry(int index, unsigned int hash,
                              Symbol* name, ClassLoaderData* loader_data);
 
+protected:
   DictionaryEntry* bucket(int i) {
     return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i);
   }
@@ -66,6 +67,8 @@ private:
     Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry);
   }
 
+  static size_t entry_size();
+
 public:
   Dictionary(int table_size);
   Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);

src/share/vm/classfile/systemDictionary.cpp

 /*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, 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
@@ -1198,8 +1198,13 @@ instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
 
     if (ik->super() != NULL) {
       Symbol*  cn = ik->super()->name();
-      resolve_super_or_fail(class_name, cn,
-                            class_loader, protection_domain, true, CHECK_(nh));
+      Klass *s = resolve_super_or_fail(class_name, cn,
+                                       class_loader, protection_domain, true, CHECK_(nh));
+      if (s != ik->super()) {
+        // The dynamically resolved super class is not the same as the one we used during dump time,
+        // so we cannot use ik.
+        return nh;
+      }
     }
 
     Array<Klass*>* interfaces = ik->local_interfaces();
@@ -1212,7 +1217,12 @@ instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
       // reinitialized yet (they will be once the interface classes
       // are loaded)
       Symbol*  name  = k->name();
-      resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
+      Klass* i = resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
+      if (k != i) {
+        // The dynamically resolved interface class is not the same as the one we used during dump time,
+        // so we cannot use ik.
+        return nh;
+      }
     }
 
     // Adjust methods to recover missing data.  They need addresses for

src/share/vm/classfile/systemDictionaryShared.hpp

 /*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2016, 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
@@ -26,6 +26,7 @@
 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP
 
+#include "classfile/dictionary.hpp"
 #include "classfile/systemDictionary.hpp"
 
 class SystemDictionaryShared: public SystemDictionary {
@@ -42,6 +43,22 @@ public:
     oop class_loader = loader_data->class_loader();
     return (class_loader == NULL);
   }
+
+  static size_t dictionary_entry_size() {
+    return sizeof(DictionaryEntry);
+  }
+  static void init_shared_dictionary_entry(Klass* k, DictionaryEntry* entry) {}
+
+  // The (non-application) CDS implementation supports only classes in the boot
+  // class loader, which ensures that the verification dependencies are the same
+  // during archive creation time and runtime. Thus we can do the dependency checks
+  // entirely during archive creation time.
+  static void add_verification_dependency(Klass* k, Symbol* accessor_clsname,
+                                          Symbol* target_clsname) {}
+  static void finalize_verification_dependencies() {}
+  static bool check_verification_dependencies(Klass* k, Handle class_loader,
+                                              Handle protection_domain,
+                                              char** message_buffer, TRAPS) {return true;}
 };
 
 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARYSHARED_HPP

src/share/vm/classfile/verificationType.cpp

 /*
- * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, 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
@@ -24,6 +24,7 @@
 
 #include "precompiled.hpp"
 #include "classfile/symbolTable.hpp"
+#include "classfile/systemDictionaryShared.hpp"
 #include "classfile/verificationType.hpp"
 #include "classfile/verifier.hpp"
 
@@ -73,7 +74,23 @@ bool VerificationType::is_reference_assignable_from(
       Klass* from_class = SystemDictionary::resolve_or_fail(
           from.name(), Handle(THREAD, klass->class_loader()),
           Handle(THREAD, klass->protection_domain()), true, CHECK_false);
-      return InstanceKlass::cast(from_class)->is_subclass_of(this_class());
+      bool result = InstanceKlass::cast(from_class)->is_subclass_of(this_class());
+      if (result && DumpSharedSpaces) {
+        if (klass()->is_subclass_of(from_class) && klass()->is_subclass_of(this_class())) {
+          // No need to save verification dependency. At run time, <klass> will be
+          // loaded from the archived only if <from_class> and <this_class> are
+          // also loaded from the archive. I.e., all 3 classes are exactly the same
+          // as we saw at archive creation time.
+        } else {
+          // Save the dependency. At run time, we need to check that the condition
+          // from_class->is_subclass_of(this_class() is still true.
+          Symbol* accessor_clsname = from.name();
+          Symbol* target_clsname = this_class()->name();
+          SystemDictionaryShared::add_verification_dependency(klass(),
+                       accessor_clsname, target_clsname);
+        }
+      }
+      return result;
     }
   } else if (is_array() && from.is_array()) {
     VerificationType comp_this = get_component(context, CHECK_false);

src/share/vm/memory/metaspaceShared.cpp

 /*
- * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2016, 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
@@ -30,6 +30,7 @@
 #include "classfile/sharedClassUtil.hpp"
 #include "classfile/symbolTable.hpp"
 #include "classfile/systemDictionary.hpp"
+#include "classfile/systemDictionaryShared.hpp"
 #include "code/codeCache.hpp"
 #include "memory/filemap.hpp"
 #include "memory/gcLocker.hpp"
@@ -684,6 +685,10 @@ void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
       exit(1);
     }
   }
+
+  // Copy the dependencies from C_HEAP-alloced GrowableArrays to RO-alloced
+  // Arrays
+  SystemDictionaryShared::finalize_verification_dependencies();
 }
 
 void MetaspaceShared::prepare_for_dumping() {

src/share/vm/oops/instanceKlass.cpp

 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, 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/javaClasses.hpp"
 #include "classfile/systemDictionary.hpp"
+#include "classfile/systemDictionaryShared.hpp"
 #include "classfile/verifier.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "compiler/compileBroker.hpp"
@@ -706,6 +707,16 @@ bool InstanceKlass::link_class_impl(
 
         // also sets rewritten
         this_oop->rewrite_class(CHECK_false);
+      } else if (this_oop()->is_shared()) {
+        ResourceMark rm(THREAD);
+        char* message_buffer; // res-allocated by check_verification_dependencies
+        Handle loader = this_oop()->class_loader();
+        Handle pd     = this_oop()->protection_domain();
+        bool verified = SystemDictionaryShared::check_verification_dependencies(this_oop(),
+                        loader, pd, &message_buffer, THREAD);
+        if (!verified) {
+          THROW_MSG_(vmSymbols::java_lang_VerifyError(), message_buffer, false);
+        }
       }
 
       // relocate jsrs and link methods after they are all rewritten

src/share/vm/prims/whitebox.cpp

 /*
- * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2016, 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 "memory/metadataFactory.hpp"
+#include "memory/metaspaceShared.hpp"
 #include "memory/universe.hpp"
 #include "oops/oop.inline.hpp"
 
@@ -914,6 +915,10 @@ WB_ENTRY(jlong, WB_MetaspaceCapacityUntilGC(JNIEnv* env, jobject wb))
   return (jlong) MetaspaceGC::capacity_until_GC();
 WB_END
 
+WB_ENTRY(jboolean, WB_IsSharedClass(JNIEnv* env, jobject wb, jclass clazz))
+  return (jboolean)MetaspaceShared::is_in_shared_space(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
+WB_END
+
 WB_ENTRY(jboolean, WB_IsMonitorInflated(JNIEnv* env, jobject wb, jobject obj))
   oop obj_oop = JNIHandles::resolve(obj);
   return (jboolean) obj_oop->mark()->has_monitor();
@@ -1034,6 +1039,7 @@ static JNINativeMethod methods[] = {
   {CC"runMemoryUnitTests", CC"()V",                   (void*)&WB_RunMemoryUnitTests},
   {CC"readFromNoaccessArea",CC"()V",                  (void*)&WB_ReadFromNoaccessArea},
   {CC"stressVirtualSpaceResize",CC"(JJJ)I",           (void*)&WB_StressVirtualSpaceResize},
+  {CC"isSharedClass", CC"(Ljava/lang/Class;)Z",       (void*)&WB_IsSharedClass },
 #if INCLUDE_ALL_GCS
   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },

test/testlibrary/whitebox/sun/hotspot/WhiteBox.java

 /*
- * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2016, 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
@@ -233,4 +233,6 @@ public class WhiteBox {
     return offset;
   }
 
+  // Class Data Sharing
+  public native boolean isSharedClass(Class<?> c);
 }