/*

 * 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.

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 */

// JvmtiTagMap

#ifndef _JAVA_JVMTI_TAG_MAP_H_

#define _JAVA_JVMTI_TAG_MAP_H_

// forward references

class JvmtiTagHashmap;

class JvmtiTagHashmapEntry;

class JvmtiTagHashmapEntryClosure;

class JvmtiTagMap :  public CHeapObj {

 private:

  enum{

    n_hashmaps = 2,                                 // encapsulates 2 hashmaps

    max_free_entries = 4096                         // maximum number of free entries per env

  };

  // memory region for young generation

  static MemRegion _young_gen;

  static void get_young_generation();

  JvmtiEnv*             _env;                       // the jvmti environment

  Mutex                 _lock;                      // lock for this tag map

  JvmtiTagHashmap*      _hashmap[n_hashmaps];       // the hashmaps

  JvmtiTagHashmapEntry* _free_entries;              // free list for this environment

  int _free_entries_count;                          // number of entries on the free list

  // create a tag map

  JvmtiTagMap(JvmtiEnv* env);

  // accessors

  inline Mutex* lock()                      { return &_lock; }

  inline JvmtiEnv* env() const              { return _env; }

  // rehash tags maps for generation start to end

  void rehash(int start, int end);

  // indicates if the object is in the young generation

  static bool is_in_young(oop o);

  // iterate over all entries in this tag map

  void entry_iterate(JvmtiTagHashmapEntryClosure* closure);

 public:

  // indicates if this tag map is locked

  bool is_locked()                          { return lock()->is_locked(); }

  // return the appropriate hashmap for a given object

  JvmtiTagHashmap* hashmap_for(oop o);

  // create/destroy entries

  JvmtiTagHashmapEntry* create_entry(jweak ref, jlong tag);

  void destroy_entry(JvmtiTagHashmapEntry* entry);

  // returns true if the hashmaps are empty

  bool is_empty();

  // return tag for the given environment

  static JvmtiTagMap* tag_map_for(JvmtiEnv* env);

  // destroy tag map

  ~JvmtiTagMap();

  // set/get tag

  void set_tag(jobject obj, jlong tag);

  jlong get_tag(jobject obj);

  // deprecated heap iteration functions

  void iterate_over_heap(jvmtiHeapObjectFilter object_filter,

                         KlassHandle klass,

                         jvmtiHeapObjectCallback heap_object_callback,

                         const void* user_data);

  void iterate_over_reachable_objects(jvmtiHeapRootCallback heap_root_callback,

                                      jvmtiStackReferenceCallback stack_ref_callback,

                                      jvmtiObjectReferenceCallback object_ref_callback,

                                      const void* user_data);

  void iterate_over_objects_reachable_from_object(jobject object,

                                                  jvmtiObjectReferenceCallback object_reference_callback,

                                                  const void* user_data);

  // advanced (JVMTI 1.1) heap iteration functions

  void iterate_through_heap(jint heap_filter,

                            KlassHandle klass,

                            const jvmtiHeapCallbacks* callbacks,

                            const void* user_data);

  void follow_references(jint heap_filter,

                         KlassHandle klass,

                         jobject initial_object,

                         const jvmtiHeapCallbacks* callbacks,

                         const void* user_data);

  // get tagged objects

  jvmtiError get_objects_with_tags(const jlong* tags, jint count,

                                   jint* count_ptr, jobject** object_result_ptr,

                                   jlong** tag_result_ptr);

  // call post-GC to rehash the tag maps.

  static void gc_epilogue(bool full);

  // call after referencing processing has completed (CMS)

  static void cms_ref_processing_epilogue();

};

#endif   /* _JAVA_JVMTI_TAG_MAP_H_ */