1 /*
2 * Copyright (c) 2003, 2010, 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 SHARE_VM_PRIMS_JVMTITAGMAP_HPP
28 #define SHARE_VM_PRIMS_JVMTITAGMAP_HPP
29
30 #ifndef JVMTI_KERNEL
31 #include "gc_interface/collectedHeap.hpp"
32 #include "jvmtifiles/jvmti.h"
33 #include "jvmtifiles/jvmtiEnv.hpp"
34 #include "memory/allocation.hpp"
35 #include "memory/genCollectedHeap.hpp"
36 #include "memory/universe.hpp"
37 #endif
38
39 // forward references
40 class JvmtiTagHashmap;
41 class JvmtiTagHashmapEntry;
42 class JvmtiTagHashmapEntryClosure;
43
44 class JvmtiTagMap : public CHeapObj {
45 private:
46
47 enum{
48 n_hashmaps = 2, // encapsulates 2 hashmaps
49 max_free_entries = 4096 // maximum number of free entries per env
50 };
51
52 // memory region for young generation
53 static MemRegion _young_gen;
54 static void get_young_generation();
55
56 JvmtiEnv* _env; // the jvmti environment
57 Mutex _lock; // lock for this tag map
58 JvmtiTagHashmap* _hashmap[n_hashmaps]; // the hashmaps
59
60 JvmtiTagHashmapEntry* _free_entries; // free list for this environment
61 int _free_entries_count; // number of entries on the free list
62
63 // create a tag map
64 JvmtiTagMap(JvmtiEnv* env);
65
66 // accessors
67 inline Mutex* lock() { return &_lock; }
68 inline JvmtiEnv* env() const { return _env; }
69
70 // rehash tags maps for generation start to end
71 void rehash(int start, int end);
72
73 // indicates if the object is in the young generation
74 static bool is_in_young(oop o);
75
76 // iterate over all entries in this tag map
77 void entry_iterate(JvmtiTagHashmapEntryClosure* closure);
78
79 public:
80
81 // indicates if this tag map is locked
82 bool is_locked() { return lock()->is_locked(); }
83
84 // return the appropriate hashmap for a given object
85 JvmtiTagHashmap* hashmap_for(oop o);
86
87 // create/destroy entries
88 JvmtiTagHashmapEntry* create_entry(jweak ref, jlong tag);
89 void destroy_entry(JvmtiTagHashmapEntry* entry);
90
91 // returns true if the hashmaps are empty
92 bool is_empty();
93
94 // return tag for the given environment
95 static JvmtiTagMap* tag_map_for(JvmtiEnv* env);
96
97 // destroy tag map
98 ~JvmtiTagMap();
99
100 // set/get tag
101 void set_tag(jobject obj, jlong tag);
102 jlong get_tag(jobject obj);
103
104 // deprecated heap iteration functions
105 void iterate_over_heap(jvmtiHeapObjectFilter object_filter,
106 KlassHandle klass,
107 jvmtiHeapObjectCallback heap_object_callback,
108 const void* user_data);
109
110 void iterate_over_reachable_objects(jvmtiHeapRootCallback heap_root_callback,
111 jvmtiStackReferenceCallback stack_ref_callback,
112 jvmtiObjectReferenceCallback object_ref_callback,
113 const void* user_data);
114
115 void iterate_over_objects_reachable_from_object(jobject object,
116 jvmtiObjectReferenceCallback object_reference_callback,
117 const void* user_data);
118
119
120 // advanced (JVMTI 1.1) heap iteration functions
121 void iterate_through_heap(jint heap_filter,
122 KlassHandle klass,
123 const jvmtiHeapCallbacks* callbacks,
124 const void* user_data);
125
126 void follow_references(jint heap_filter,
127 KlassHandle klass,
128 jobject initial_object,
129 const jvmtiHeapCallbacks* callbacks,
130 const void* user_data);
131
132 // get tagged objects
133 jvmtiError get_objects_with_tags(const jlong* tags, jint count,
134 jint* count_ptr, jobject** object_result_ptr,
135 jlong** tag_result_ptr);
136
137 // call post-GC to rehash the tag maps.
138 static void gc_epilogue(bool full);
139
140 // call after referencing processing has completed (CMS)
141 static void cms_ref_processing_epilogue();
142 };
143
144 #endif // SHARE_VM_PRIMS_JVMTITAGMAP_HPP