Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2016, 2018, 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.

  *

  */

 #include "precompiled.hpp"

 #include "classfile/classLoaderData.inline.hpp"

 #include "classfile/javaClasses.hpp"

 #include "classfile/symbolTable.hpp"

 #include "classfile/systemDictionary.hpp"

 #include "jfr/jfr.hpp"

 #include "jfr/jni/jfrGetAllEventClasses.hpp"

 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"

 #include "jfr/recorder/checkpoint/types/jfrTypeSet.hpp"

 #include "jfr/recorder/checkpoint/types/jfrTypeSetUtils.hpp"

 #include "jfr/recorder/checkpoint/types/jfrTypeSetWriter.hpp"

 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp"

 #include "jfr/recorder/storage/jfrBuffer.hpp"

 #include "jfr/utilities/jfrHashtable.hpp"

 #include "jfr/utilities/jfrTypes.hpp"

 #include "memory/iterator.hpp"

 #include "memory/resourceArea.hpp"

 #include "oops/instanceKlass.hpp"

 #include "oops/objArrayKlass.hpp"

 #include "oops/oop.inline.hpp"

 #include "memory/resourceArea.hpp"

 #include "utilities/accessFlags.hpp"

 // incremented on each checkpoint

 static u8 checkpoint_id = 0;

 // creates a unique id by combining a checkpoint relative symbol id (2^24)

 // with the current checkpoint id (2^40)

 #define CREATE_SYMBOL_ID(sym_id) (((u8)((checkpoint_id << 24) | sym_id)))

 #define CREATE_PACKAGE_ID(pkg_id) (((u8)((checkpoint_id << 24) | pkg_id)))

 typedef const Klass* KlassPtr;

 typedef const ClassLoaderData* CldPtr;

 typedef const Method* MethodPtr;

 typedef const Symbol* SymbolPtr;

 typedef const JfrSymbolId::SymbolEntry* SymbolEntryPtr;

 typedef const JfrSymbolId::CStringEntry* CStringEntryPtr;

 inline uintptr_t package_name_hash(const char *s) {

   uintptr_t val = 0;

   while (*s != 0) {

     val = *s++ + 31 * val;

   }

   return val;

 }

 static traceid package_id(KlassPtr klass, JfrArtifactSet* artifacts) {

   assert(klass != NULL, "invariant");

   char* klass_name = klass->name()->as_C_string(); // uses ResourceMark declared in JfrTypeSet::serialize()

   const char* pkg_name = ClassLoader::package_from_name(klass_name, NULL);

   if (pkg_name == NULL) {

     return 0;

   }

   return CREATE_PACKAGE_ID(artifacts->markPackage(pkg_name, package_name_hash(pkg_name)));

 }

 static traceid cld_id(CldPtr cld) {

   assert(cld != NULL, "invariant");

   return cld->is_anonymous() ? 0 : TRACE_ID(cld);

 }

 static void tag_leakp_klass_artifacts(KlassPtr k, bool class_unload) {

   assert(k != NULL, "invariant");

   CldPtr cld = k->class_loader_data();

   assert(cld != NULL, "invariant");

   if (!cld->is_anonymous()) {

     tag_leakp_artifact(cld, class_unload);

   }

 }

 class TagLeakpKlassArtifact {

   bool _class_unload;

  public:

   TagLeakpKlassArtifact(bool class_unload) : _class_unload(class_unload) {}

   bool operator()(KlassPtr klass) {

     if (_class_unload) {

       if (LEAKP_USED_THIS_EPOCH(klass)) {

         tag_leakp_klass_artifacts(klass, _class_unload);

       }

     } else {

       if (LEAKP_USED_PREV_EPOCH(klass)) {

         tag_leakp_klass_artifacts(klass, _class_unload);

       }

     }

     return true;

   }

 };

 /*

  * In C++03, functions used as template parameters must have external linkage;

  * this restriction was removed in C++11. Change back to "static" and

  * rename functions when C++11 becomes available.

  *

  * The weird naming is an effort to decrease the risk of name clashes.

  */

 int write__artifact__klass(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* k) {

   assert(writer != NULL, "invariant");

   assert(artifacts != NULL, "invariant");

   assert(k != NULL, "invariant");

   KlassPtr klass = (KlassPtr)k;

   traceid pkg_id = 0;

   KlassPtr theklass = klass;

   if (theklass->oop_is_objArray()) {

     const ObjArrayKlass* obj_arr_klass = ObjArrayKlass::cast((Klass*)klass);

     theklass = obj_arr_klass->bottom_klass();

   }

   if (theklass->oop_is_instance()) {

     pkg_id = package_id(theklass, artifacts);

   } else {

     assert(theklass->oop_is_typeArray(), "invariant");

   }

   const traceid symbol_id = artifacts->mark(klass);

   assert(symbol_id > 0, "need to have an address for symbol!");

   writer->write(TRACE_ID(klass));

   writer->write(cld_id(klass->class_loader_data()));

   writer->write((traceid)CREATE_SYMBOL_ID(symbol_id));

   writer->write(pkg_id);

   writer->write((s4)klass->access_flags().get_flags());

   return 1;

 }

 typedef LeakPredicate<KlassPtr> LeakKlassPredicate;

 typedef JfrPredicatedArtifactWriterImplHost<KlassPtr, LeakKlassPredicate, write__artifact__klass> LeakKlassWriterImpl;

 typedef JfrArtifactWriterHost<LeakKlassWriterImpl, TYPE_CLASS> LeakKlassWriter;

 typedef JfrArtifactWriterImplHost<KlassPtr, write__artifact__klass> KlassWriterImpl;

 typedef JfrArtifactWriterHost<KlassWriterImpl, TYPE_CLASS> KlassWriter;

 int write__artifact__method(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* m) {

   assert(writer != NULL, "invariant");

   assert(artifacts != NULL, "invariant");

   assert(m != NULL, "invariant");

   MethodPtr method = (MethodPtr)m;

   const traceid method_name_symbol_id = artifacts->mark(method->name());

   assert(method_name_symbol_id > 0, "invariant");

   const traceid method_sig_symbol_id = artifacts->mark(method->signature());

   assert(method_sig_symbol_id > 0, "invariant");

   KlassPtr klass = method->method_holder();

   assert(klass != NULL, "invariant");

   assert(METHOD_USED_ANY_EPOCH(klass), "invariant");

   writer->write((u8)METHOD_ID(klass, method));

   writer->write((u8)TRACE_ID(klass));

   writer->write((u8)CREATE_SYMBOL_ID(method_name_symbol_id));

   writer->write((u8)CREATE_SYMBOL_ID(method_sig_symbol_id));

   writer->write((u2)method->access_flags().get_flags());

   writer->write(const_cast<Method*>(method)->is_hidden() ? (u1)1 : (u1)0);

   return 1;

 }

 typedef JfrArtifactWriterImplHost<MethodPtr, write__artifact__method> MethodWriterImplTarget;

 typedef JfrArtifactWriterHost<MethodWriterImplTarget, TYPE_METHOD> MethodWriterImpl;

 int write__artifact__package(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* p) {

   assert(writer != NULL, "invariant");

   assert(artifacts != NULL, "invariant");

   assert(p != NULL, "invariant");

   CStringEntryPtr entry = (CStringEntryPtr)p;

   const traceid package_name_symbol_id = artifacts->mark(entry->value(), package_name_hash(entry->value()));

   assert(package_name_symbol_id > 0, "invariant");

   writer->write((traceid)CREATE_PACKAGE_ID(entry->id()));

   writer->write((traceid)CREATE_SYMBOL_ID(package_name_symbol_id));

   writer->write((bool)true); // exported

   return 1;

 }

 int write__artifact__classloader(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* c) {

   assert(c != NULL, "invariant");

   CldPtr cld = (CldPtr)c;

   assert(!cld->is_anonymous(), "invariant");

   const traceid cld_id = TRACE_ID(cld);

   // class loader type

   const Klass* class_loader_klass = cld->class_loader() != NULL ? cld->class_loader()->klass() : NULL;

   if (class_loader_klass == NULL) {

     // (primordial) boot class loader

     writer->write(cld_id); // class loader instance id

     writer->write((traceid)0);  // class loader type id (absence of)

     writer->write((traceid)CREATE_SYMBOL_ID(1)); // 1 maps to synthetic name -> "bootstrap"

   } else {

     Symbol* symbol_name = class_loader_klass->name();

     const traceid symbol_name_id = symbol_name != NULL ? artifacts->mark(symbol_name) : 0;

     writer->write(cld_id); // class loader instance id

     writer->write(TRACE_ID(class_loader_klass)); // class loader type id

     writer->write(symbol_name_id == 0 ? (traceid)0 :

       (traceid)CREATE_SYMBOL_ID(symbol_name_id)); // class loader instance name

   }

   return 1;

 }

 typedef LeakPredicate<CldPtr> LeakCldPredicate;

 int _compare_cld_ptr_(CldPtr const& lhs, CldPtr const& rhs) { return lhs > rhs ? 1 : (lhs < rhs) ? -1 : 0; }

 typedef UniquePredicate<CldPtr, _compare_cld_ptr_> CldPredicate;

 typedef JfrPredicatedArtifactWriterImplHost<CldPtr, LeakCldPredicate, write__artifact__classloader> LeakCldWriterImpl;

 typedef JfrPredicatedArtifactWriterImplHost<CldPtr, CldPredicate, write__artifact__classloader> CldWriterImpl;

 typedef JfrArtifactWriterHost<LeakCldWriterImpl, TYPE_CLASSLOADER> LeakCldWriter;

 typedef JfrArtifactWriterHost<CldWriterImpl, TYPE_CLASSLOADER> CldWriter;

 typedef const JfrSymbolId::SymbolEntry* SymbolEntryPtr;

 static int write__artifact__symbol__entry__(JfrCheckpointWriter* writer,

                                             SymbolEntryPtr entry) {

   assert(writer != NULL, "invariant");

   assert(entry != NULL, "invariant");

   ResourceMark rm;

   writer->write(CREATE_SYMBOL_ID(entry->id()));

   writer->write(entry->value()->as_C_string());

   return 1;

 }

 int write__artifact__symbol__entry(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* e) {

   assert(e != NULL, "invariant");

   return write__artifact__symbol__entry__(writer, (SymbolEntryPtr)e);

 }

 typedef JfrArtifactWriterImplHost<SymbolEntryPtr, write__artifact__symbol__entry> SymbolEntryWriterImpl;

 typedef JfrArtifactWriterHost<SymbolEntryWriterImpl, TYPE_SYMBOL> SymbolEntryWriter;

 typedef const JfrSymbolId::CStringEntry* CStringEntryPtr;

 static int write__artifact__cstring__entry__(JfrCheckpointWriter* writer, CStringEntryPtr entry) {

   assert(writer != NULL, "invariant");

   assert(entry != NULL, "invariant");

   writer->write(CREATE_SYMBOL_ID(entry->id()));

   writer->write(entry->value());

   return 1;

 }

 int write__artifact__cstring__entry(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* e) {

   assert(e != NULL, "invariant");

   return write__artifact__cstring__entry__(writer, (CStringEntryPtr)e);

 }

 typedef JfrArtifactWriterImplHost<CStringEntryPtr, write__artifact__cstring__entry> CStringEntryWriterImpl;

 typedef JfrArtifactWriterHost<CStringEntryWriterImpl, TYPE_SYMBOL> CStringEntryWriter;

 int write__artifact__klass__symbol(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, const void* k) {

   assert(writer != NULL, "invariant");

   assert(artifacts != NULL, "invaiant");

   assert(k != NULL, "invariant");

   const InstanceKlass* const ik = (const InstanceKlass*)k;

   if (ik->is_anonymous()) {

     CStringEntryPtr entry =

       artifacts->map_cstring(JfrSymbolId::anonymous_klass_name_hash_code(ik));

     assert(entry != NULL, "invariant");

     return write__artifact__cstring__entry__(writer, entry);

   }

   SymbolEntryPtr entry = artifacts->map_symbol(JfrSymbolId::regular_klass_name_hash_code(ik));

   return write__artifact__symbol__entry__(writer, entry);

 }

 int _compare_traceid_(const traceid& lhs, const traceid& rhs) {

   return lhs > rhs ? 1 : (lhs < rhs) ? -1 : 0;

 }

 template <template <typename> class Predicate>

 class KlassSymbolWriterImpl {

  private:

   JfrCheckpointWriter* _writer;

   JfrArtifactSet* _artifacts;

   Predicate<KlassPtr> _predicate;

   MethodUsedPredicate<true> _method_used_predicate;

   MethodFlagPredicate _method_flag_predicate;

   UniquePredicate<traceid, _compare_traceid_> _unique_predicate;

   int klass_symbols(KlassPtr klass);

   int class_loader_symbols(CldPtr cld);

   int method_symbols(KlassPtr klass);

  public:

   typedef KlassPtr Type;

   KlassSymbolWriterImpl(JfrCheckpointWriter* writer,

                         JfrArtifactSet* artifacts,

                         bool class_unload) : _writer(writer),

                                              _artifacts(artifacts),

                                              _predicate(class_unload),

                                              _method_used_predicate(class_unload),

                                              _method_flag_predicate(class_unload),

                                              _unique_predicate(class_unload) {}

   int operator()(KlassPtr klass) {

     assert(klass != NULL, "invariant");

     int count = 0;

     if (_predicate(klass)) {

       count += klass_symbols(klass);

       CldPtr cld = klass->class_loader_data();

       assert(cld != NULL, "invariant");

       if (!cld->is_anonymous()) {

         count += class_loader_symbols(cld);

       }

       if (_method_used_predicate(klass)) {

         count += method_symbols(klass);

       }

     }

     return count;

   }

 };

 template <template <typename> class Predicate>

 int KlassSymbolWriterImpl<Predicate>::klass_symbols(KlassPtr klass) {

   assert(klass != NULL, "invariant");

   assert(_predicate(klass), "invariant");

   const InstanceKlass* const ik = (const InstanceKlass*)klass;

   if (ik->is_anonymous()) {

     CStringEntryPtr entry =

       this->_artifacts->map_cstring(JfrSymbolId::anonymous_klass_name_hash_code(ik));

     assert(entry != NULL, "invariant");

     return _unique_predicate(entry->id()) ? write__artifact__cstring__entry__(this->_writer, entry) : 0;

   }

   SymbolEntryPtr entry = this->_artifacts->map_symbol(ik->name());

   assert(entry != NULL, "invariant");

   return _unique_predicate(entry->id()) ? write__artifact__symbol__entry__(this->_writer, entry) : 0;

 }

 template <template <typename> class Predicate>

 int KlassSymbolWriterImpl<Predicate>::class_loader_symbols(CldPtr cld) {

   assert(cld != NULL, "invariant");

   assert(!cld->is_anonymous(), "invariant");

   int count = 0;

   // class loader type

   const Klass* class_loader_klass = cld->class_loader() != NULL ? cld->class_loader()->klass() : NULL;

   if (class_loader_klass == NULL) {

     // (primordial) boot class loader

     CStringEntryPtr entry = this->_artifacts->map_cstring(0);

     assert(entry != NULL, "invariant");

     assert(strncmp(entry->literal(),

       BOOTSTRAP_LOADER_NAME,

       BOOTSTRAP_LOADER_NAME_LEN) == 0, "invariant");

     if (_unique_predicate(entry->id())) {

       count += write__artifact__cstring__entry__(this->_writer, entry);

     }

   } else {

     const Symbol* class_loader_name = class_loader_klass->name()/* XXX TODO cld->name()*/;

     if (class_loader_name != NULL) {

       SymbolEntryPtr entry = this->_artifacts->map_symbol(class_loader_name);

       assert(entry != NULL, "invariant");

       if (_unique_predicate(entry->id())) {

         count += write__artifact__symbol__entry__(this->_writer, entry);

       }

     }

   }

   return count;

 }

 template <template <typename> class Predicate>

 int KlassSymbolWriterImpl<Predicate>::method_symbols(KlassPtr klass) {

   assert(_predicate(klass), "invariant");

   assert(_method_used_predicate(klass), "invariant");

   assert(METHOD_AND_CLASS_USED_ANY_EPOCH(klass), "invariant");

   int count = 0;

   const InstanceKlass* const ik = InstanceKlass::cast((Klass*)klass);

   const int len = ik->methods()->length();

   for (int i = 0; i < len; ++i) {

     MethodPtr method = ik->methods()->at(i);

     if (_method_flag_predicate(method)) {

       SymbolEntryPtr entry = this->_artifacts->map_symbol(method->name());

       assert(entry != NULL, "invariant");

       if (_unique_predicate(entry->id())) {

         count += write__artifact__symbol__entry__(this->_writer, entry);

       }

       entry = this->_artifacts->map_symbol(method->signature());

       assert(entry != NULL, "invariant");

       if (_unique_predicate(entry->id())) {

         count += write__artifact__symbol__entry__(this->_writer, entry);

       }

     }

   }

   return count;

 }

 typedef KlassSymbolWriterImpl<LeakPredicate> LeakKlassSymbolWriterImpl;

 typedef JfrArtifactWriterHost<LeakKlassSymbolWriterImpl, TYPE_SYMBOL> LeakKlassSymbolWriter;

 class ClearKlassAndMethods {

  private:

   ClearArtifact<KlassPtr> _clear_klass_tag_bits;

   ClearArtifact<MethodPtr> _clear_method_flag;

   MethodUsedPredicate<false> _method_used_predicate;

  public:

   ClearKlassAndMethods(bool class_unload) : _clear_klass_tag_bits(class_unload),

                                             _clear_method_flag(class_unload),

                                             _method_used_predicate(class_unload) {}

   bool operator()(KlassPtr klass) {

     if (_method_used_predicate(klass)) {

       const InstanceKlass* ik = InstanceKlass::cast((Klass*)klass);

       const int len = ik->methods()->length();

       for (int i = 0; i < len; ++i) {

         MethodPtr method = ik->methods()->at(i);

         _clear_method_flag(method);

       }

     }

     _clear_klass_tag_bits(klass);

     return true;

   }

 };

 typedef CompositeFunctor<KlassPtr,

                          TagLeakpKlassArtifact,

                          LeakKlassWriter> LeakpKlassArtifactTagging;

 typedef CompositeFunctor<KlassPtr,

                          LeakpKlassArtifactTagging,

                          KlassWriter> CompositeKlassWriter;

 typedef CompositeFunctor<KlassPtr,

                          CompositeKlassWriter,

                          KlassArtifactRegistrator> CompositeKlassWriterRegistration;

 typedef CompositeFunctor<KlassPtr,

                          KlassWriter,

                          KlassArtifactRegistrator> KlassWriterRegistration;

 typedef JfrArtifactCallbackHost<KlassPtr, KlassWriterRegistration> KlassCallback;

 typedef JfrArtifactCallbackHost<KlassPtr, CompositeKlassWriterRegistration> CompositeKlassCallback;

 /*

  * Composite operation

  *

  * TagLeakpKlassArtifact ->

  *   LeakpPredicate ->

  *     LeakpKlassWriter ->

  *       KlassPredicate ->

  *         KlassWriter ->

  *           KlassWriterRegistration

  */

 void JfrTypeSet::write_klass_constants(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer) {

   assert(!_artifacts->has_klass_entries(), "invariant");

   KlassArtifactRegistrator reg(_artifacts);

   KlassWriter kw(writer, _artifacts, _class_unload);

   KlassWriterRegistration kwr(&kw, &reg);

   if (leakp_writer == NULL) {

     KlassCallback callback(&kwr);

     _subsystem_callback = &callback;

     do_klasses();

     return;

   }

   TagLeakpKlassArtifact tagging(_class_unload);

   LeakKlassWriter lkw(leakp_writer, _artifacts, _class_unload);

   LeakpKlassArtifactTagging lpkat(&tagging, &lkw);

   CompositeKlassWriter ckw(&lpkat, &kw);

   CompositeKlassWriterRegistration ckwr(&ckw, &reg);

   CompositeKlassCallback callback(&ckwr);

   _subsystem_callback = &callback;

   do_klasses();

 }

 typedef JfrArtifactWriterImplHost<CStringEntryPtr, write__artifact__package> PackageEntryWriterImpl;

 typedef JfrArtifactWriterHost<PackageEntryWriterImpl, TYPE_PACKAGE> PackageEntryWriter;

 void JfrTypeSet::write_package_constants(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer) {

   assert(_artifacts->has_klass_entries(), "invariant");

   assert(writer != NULL, "invariant");

   // below jdk9 there is no oop for packages, so nothing to do with leakp_writer

   // just write packages

   PackageEntryWriter pw(writer, _artifacts, _class_unload);

   _artifacts->iterate_packages(pw);

 }

 typedef CompositeFunctor<CldPtr, CldWriter, ClearArtifact<CldPtr> > CldWriterWithClear;

 typedef CompositeFunctor<CldPtr, LeakCldWriter, CldWriter> CompositeCldWriter;

 typedef CompositeFunctor<CldPtr, CompositeCldWriter, ClearArtifact<CldPtr> > CompositeCldWriterWithClear;

 typedef JfrArtifactCallbackHost<CldPtr, CldWriterWithClear> CldCallback;

 typedef JfrArtifactCallbackHost<CldPtr, CompositeCldWriterWithClear> CompositeCldCallback;

 class CldFieldSelector {

  public:

   typedef CldPtr TypePtr;

   static TypePtr select(KlassPtr klass) {

     assert(klass != NULL, "invariant");

     CldPtr cld = klass->class_loader_data();

     return cld->is_anonymous() ? NULL : cld;

   }

 };

 typedef KlassToFieldEnvelope<CldFieldSelector, CldWriterWithClear> KlassCldWriterWithClear;

 typedef KlassToFieldEnvelope<CldFieldSelector, CompositeCldWriterWithClear> KlassCompositeCldWriterWithClear;

 /*

  * Composite operation

  *

  * LeakpClassLoaderWriter ->

  *   ClassLoaderWriter ->

  *     ClearArtifact<ClassLoaderData>

  */

 void JfrTypeSet::write_class_loader_constants(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer) {

   assert(_artifacts->has_klass_entries(), "invariant");

   ClearArtifact<CldPtr> clear(_class_unload);

   CldWriter cldw(writer, _artifacts, _class_unload);

   if (leakp_writer == NULL) {

     CldWriterWithClear cldwwc(&cldw, &clear);

     KlassCldWriterWithClear kcldwwc(&cldwwc);

     _artifacts->iterate_klasses(kcldwwc);

     CldCallback callback(&cldwwc);

     _subsystem_callback = &callback;

     do_class_loaders();

     return;

   }

   LeakCldWriter lcldw(leakp_writer, _artifacts, _class_unload);

   CompositeCldWriter ccldw(&lcldw, &cldw);

   CompositeCldWriterWithClear ccldwwc(&ccldw, &clear);

   KlassCompositeCldWriterWithClear kcclwwc(&ccldwwc);

   _artifacts->iterate_klasses(kcclwwc);

   CompositeCldCallback callback(&ccldwwc);

   _subsystem_callback = &callback;

   do_class_loaders();

 }

 template <bool predicate_bool, typename MethodFunctor>

 class MethodIteratorHost {

  private:

   MethodFunctor _method_functor;

   MethodUsedPredicate<predicate_bool> _method_used_predicate;

   MethodFlagPredicate _method_flag_predicate;

  public:

   MethodIteratorHost(JfrCheckpointWriter* writer,

                      JfrArtifactSet* artifacts,

                      bool class_unload,

                      bool skip_header = false) :

     _method_functor(writer, artifacts, class_unload, skip_header),

     _method_used_predicate(class_unload),

     _method_flag_predicate(class_unload) {}

   bool operator()(KlassPtr klass) {

     if (_method_used_predicate(klass)) {

       assert(METHOD_AND_CLASS_USED_ANY_EPOCH(klass), "invariant");

       const InstanceKlass* ik = InstanceKlass::cast((Klass*)klass);

       const int len = ik->methods()->length();

       for (int i = 0; i < len; ++i) {

         MethodPtr method = ik->methods()->at(i);

         if (_method_flag_predicate(method)) {

           _method_functor(method);

         }

       }

     }

     return true;

   }

   int count() const { return _method_functor.count(); }

   void add(int count) { _method_functor.add(count); }

 };

 typedef MethodIteratorHost<true /*leakp */,  MethodWriterImpl> LeakMethodWriter;

 typedef MethodIteratorHost<false, MethodWriterImpl> MethodWriter;

 typedef CompositeFunctor<KlassPtr, LeakMethodWriter, MethodWriter> CompositeMethodWriter;

 /*

  * Composite operation

  *

  * LeakpMethodWriter ->

  *   MethodWriter

  */

 void JfrTypeSet::write_method_constants(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer) {

   assert(_artifacts->has_klass_entries(), "invariant");

   MethodWriter mw(writer, _artifacts, _class_unload);

   if (leakp_writer == NULL) {

     _artifacts->iterate_klasses(mw);

     return;

   }

   LeakMethodWriter lpmw(leakp_writer, _artifacts, _class_unload);

   CompositeMethodWriter cmw(&lpmw, &mw);

   _artifacts->iterate_klasses(cmw);

 }

 static void write_symbols_leakp(JfrCheckpointWriter* leakp_writer, JfrArtifactSet* artifacts, bool class_unload) {

   assert(leakp_writer != NULL, "invariant");

   assert(artifacts != NULL, "invariant");

   LeakKlassSymbolWriter lpksw(leakp_writer, artifacts, class_unload);

   artifacts->iterate_klasses(lpksw);

 }

 static void write_symbols(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, JfrArtifactSet* artifacts, bool class_unload) {

   assert(writer != NULL, "invariant");

   assert(artifacts != NULL, "invariant");

   if (leakp_writer != NULL) {

     write_symbols_leakp(leakp_writer, artifacts, class_unload);

   }

   // iterate all registered symbols

   SymbolEntryWriter symbol_writer(writer, artifacts, class_unload);

   artifacts->iterate_symbols(symbol_writer);

   CStringEntryWriter cstring_writer(writer, artifacts, class_unload, true); // skip header

   artifacts->iterate_cstrings(cstring_writer);

   symbol_writer.add(cstring_writer.count());

 }

 bool JfrTypeSet::_class_unload = false;

 JfrArtifactSet* JfrTypeSet::_artifacts = NULL;

 JfrArtifactClosure* JfrTypeSet::_subsystem_callback = NULL;

 void JfrTypeSet::write_symbol_constants(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer) {

   assert(writer != NULL, "invariant");

   assert(_artifacts->has_klass_entries(), "invariant");

   write_symbols(writer, leakp_writer, _artifacts, _class_unload);

 }

 void JfrTypeSet::do_unloaded_klass(Klass* klass) {

   assert(klass != NULL, "invariant");

   assert(_subsystem_callback != NULL, "invariant");

   if (IS_JDK_JFR_EVENT_SUBKLASS(klass)) {

     JfrEventClasses::increment_unloaded_event_class();

   }

   if (USED_THIS_EPOCH(klass)) { // includes leakp subset

     _subsystem_callback->do_artifact(klass);

     return;

   }

   if (klass->is_subclass_of(SystemDictionary::ClassLoader_klass()) || klass == SystemDictionary::Object_klass()) {

     SET_LEAKP_USED_THIS_EPOCH(klass); // tag leakp "safe byte" for subset inclusion

     _subsystem_callback->do_artifact(klass);

   }

 }

 void JfrTypeSet::do_klass(Klass* klass) {

   assert(klass != NULL, "invariant");

   assert(_subsystem_callback != NULL, "invariant");

   if (USED_PREV_EPOCH(klass)) { // includes leakp subset

     _subsystem_callback->do_artifact(klass);

     return;

   }

   if (klass->is_subclass_of(SystemDictionary::ClassLoader_klass()) || klass == SystemDictionary::Object_klass()) {

     SET_LEAKP_USED_PREV_EPOCH(klass); // tag leakp "safe byte" for subset inclusion

     _subsystem_callback->do_artifact(klass);

   }

 }

 void JfrTypeSet::do_klasses() {

   if (_class_unload) {

     ClassLoaderDataGraph::classes_unloading_do(&do_unloaded_klass);

     return;

   }

   ClassLoaderDataGraph::classes_do(&do_klass);

 }

 void JfrTypeSet::do_unloaded_class_loader_data(ClassLoaderData* cld) {

   assert(_subsystem_callback != NULL, "invariant");

   if (ANY_USED_THIS_EPOCH(cld)) { // includes leakp subset

     _subsystem_callback->do_artifact(cld);

   }

 }

 void JfrTypeSet::do_class_loader_data(ClassLoaderData* cld) {

   assert(_subsystem_callback != NULL, "invariant");

   if (ANY_USED_PREV_EPOCH(cld)) { // includes leakp subset

     _subsystem_callback->do_artifact(cld);

   }

 }

 class CLDCallback : public CLDClosure {

  private:

   bool _class_unload;

  public:

   CLDCallback(bool class_unload) : _class_unload(class_unload) {}

   void do_cld(ClassLoaderData* cld) {

      assert(cld != NULL, "invariant");

     if (cld->is_anonymous()) {

       return;

     }

     if (_class_unload) {

       JfrTypeSet::do_unloaded_class_loader_data(cld);

       return;

     }

     JfrTypeSet::do_class_loader_data(cld);

   }

 };

 void JfrTypeSet::do_class_loaders() {

   CLDCallback cld_cb(_class_unload);

   if (_class_unload) {

     ClassLoaderDataGraph::cld_unloading_do(&cld_cb);

     return;

   }

   ClassLoaderDataGraph::cld_do(&cld_cb);

 }

 static void clear_artifacts(JfrArtifactSet* artifacts,

                             bool class_unload) {

   assert(artifacts != NULL, "invariant");

   assert(artifacts->has_klass_entries(), "invariant");

   // untag

   ClearKlassAndMethods clear(class_unload);

   artifacts->iterate_klasses(clear);

   artifacts->clear();

 }

 /**

  * Write all "tagged" (in-use) constant artifacts and their dependencies.

  */

 void JfrTypeSet::serialize(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload) {

   assert(writer != NULL, "invariant");

   ResourceMark rm;

   // initialization begin

   _class_unload = class_unload;

   ++checkpoint_id;

   if (_artifacts == NULL) {

     _artifacts = new JfrArtifactSet(class_unload);

     _subsystem_callback = NULL;

   } else {

     _artifacts->initialize(class_unload);

     _subsystem_callback = NULL;

   }

   assert(_artifacts != NULL, "invariant");

   assert(!_artifacts->has_klass_entries(), "invariant");

   assert(_subsystem_callback == NULL, "invariant");

   // initialization complete

   // write order is important because an individual write step

   // might tag an artifact to be written in a subsequent step

   write_klass_constants(writer, leakp_writer);

   if (_artifacts->has_klass_entries()) {

     write_package_constants(writer, leakp_writer);

     write_class_loader_constants(writer, leakp_writer);

     write_method_constants(writer, leakp_writer);

     write_symbol_constants(writer, leakp_writer);

     clear_artifacts(_artifacts, class_unload);

   }

 }