1 /*
2 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // JvmtiTagMap
26
27 #ifndef _JAVA_JVMTI_TAG_MAP_H_
28 #define _JAVA_JVMTI_TAG_MAP_H_
29
30 // forward references
31 class JvmtiTagHashmap;
32 class JvmtiTagHashmapEntry;
33 class JvmtiTagHashmapEntryClosure;
34
35 class JvmtiTagMap : public CHeapObj {
36 private:
37
38 enum{
39 n_hashmaps = 2, // encapsulates 2 hashmaps
40 max_free_entries = 4096 // maximum number of free entries per env
41 };
42
43 // memory region for young generation
44 static MemRegion _young_gen;
45 static void get_young_generation();
46
47 JvmtiEnv* _env; // the jvmti environment
48 Mutex _lock; // lock for this tag map
49 JvmtiTagHashmap* _hashmap[n_hashmaps]; // the hashmaps
50
51 JvmtiTagHashmapEntry* _free_entries; // free list for this environment
52 int _free_entries_count; // number of entries on the free list
53
54 // create a tag map
55 JvmtiTagMap(JvmtiEnv* env);
56
57 // accessors
58 inline Mutex* lock() { return &_lock; }
59 inline JvmtiEnv* env() const { return _env; }
60
61 // rehash tags maps for generation start to end
62 void rehash(int start, int end);
63
64 // indicates if the object is in the young generation
65 static bool is_in_young(oop o);
66
67 // iterate over all entries in this tag map
68 void entry_iterate(JvmtiTagHashmapEntryClosure* closure);
69
70 public:
71
72 // indicates if this tag map is locked
73 bool is_locked() { return lock()->is_locked(); }
74
75 // return the appropriate hashmap for a given object
76 JvmtiTagHashmap* hashmap_for(oop o);
77
78 // create/destroy entries
79 JvmtiTagHashmapEntry* create_entry(jweak ref, jlong tag);
80 void destroy_entry(JvmtiTagHashmapEntry* entry);
81
82 // returns true if the hashmaps are empty
83 bool is_empty();
84
85 // return tag for the given environment
86 static JvmtiTagMap* tag_map_for(JvmtiEnv* env);
87
88 // destroy tag map
89 ~JvmtiTagMap();
90
91 // set/get tag
92 void set_tag(jobject obj, jlong tag);
93 jlong get_tag(jobject obj);
94
95 // deprecated heap iteration functions
96 void iterate_over_heap(jvmtiHeapObjectFilter object_filter,
97 KlassHandle klass,
98 jvmtiHeapObjectCallback heap_object_callback,
99 const void* user_data);
100
101 void iterate_over_reachable_objects(jvmtiHeapRootCallback heap_root_callback,
102 jvmtiStackReferenceCallback stack_ref_callback,
103 jvmtiObjectReferenceCallback object_ref_callback,
104 const void* user_data);
105
106 void iterate_over_objects_reachable_from_object(jobject object,
107 jvmtiObjectReferenceCallback object_reference_callback,
108 const void* user_data);
109
110
111 // advanced (JVMTI 1.1) heap iteration functions
112 void iterate_through_heap(jint heap_filter,
113 KlassHandle klass,
114 const jvmtiHeapCallbacks* callbacks,
115 const void* user_data);
116
117 void follow_references(jint heap_filter,
118 KlassHandle klass,
119 jobject initial_object,
120 const jvmtiHeapCallbacks* callbacks,
121 const void* user_data);
122
123 // get tagged objects
124 jvmtiError get_objects_with_tags(const jlong* tags, jint count,
125 jint* count_ptr, jobject** object_result_ptr,
126 jlong** tag_result_ptr);
127
128 // call post-GC to rehash the tag maps.
129 static void gc_epilogue(bool full);
130
131 // call after referencing processing has completed (CMS)
132 static void cms_ref_processing_epilogue();
133 };
134
135 #endif /* _JAVA_JVMTI_TAG_MAP_H_ */