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 #ifndef SHARE_CLASSFILE_CLASSLOADERDATA_HPP
26 #define SHARE_CLASSFILE_CLASSLOADERDATA_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/memRegion.hpp"
30 #include "memory/metaspace.hpp"
31 #include "oops/oopHandle.hpp"
32 #include "oops/weakHandle.hpp"
33 #include "runtime/atomic.hpp"
34 #include "runtime/mutex.hpp"
35 #include "utilities/growableArray.hpp"
36 #include "utilities/macros.hpp"
37 #if INCLUDE_JFR
38 #include "jfr/support/jfrTraceIdExtension.hpp"
39 #endif
40
41 // external name (synthetic) for the primordial "bootstrap" class loader instance
42 #define BOOTSTRAP_LOADER_NAME "bootstrap"
43 #define BOOTSTRAP_LOADER_NAME_LEN 9
44
45 //
46 // A class loader represents a linkset. Conceptually, a linkset identifies
47 // the complete transitive closure of resolved links that a dynamic linker can
48 // produce.
49 //
50 // A ClassLoaderData also encapsulates the allocation space, called a metaspace,
51 // used by the dynamic linker to allocate the runtime representation of all
52 // the types it defines.
53 //
54 // ClassLoaderData are stored in the runtime representation of classes,
55 // and provides iterators for root tracing and other GC operations.
56
57 class ClassLoaderDataGraph;
58 class JNIMethodBlock;
59 class ModuleEntry;
60 class PackageEntry;
61 class ModuleEntryTable;
62 class PackageEntryTable;
63 class DictionaryEntry;
64 class Dictionary;
65
66 // ClassLoaderData class
67
68 class ClassLoaderData : public CHeapObj<mtClass> {
69 friend class VMStructs;
70
71 private:
72 class ChunkedHandleList {
73 struct Chunk : public CHeapObj<mtClass> {
74 static const size_t CAPACITY = 32;
75
76 oop _data[CAPACITY];
77 volatile juint _size;
78 Chunk* _next;
79
80 Chunk(Chunk* c) : _size(0), _next(c) { }
81 };
82
83 Chunk* volatile _head;
84
85 void oops_do_chunk(OopClosure* f, Chunk* c, const juint size);
96 void oops_do(OopClosure* f);
97
98 int count() const;
99 };
100
101 friend class ClassLoaderDataGraph;
102 friend class ClassLoaderDataGraphIterator;
103 friend class ClassLoaderDataGraphKlassIteratorAtomic;
104 friend class ClassLoaderDataGraphKlassIteratorStatic;
105 friend class ClassLoaderDataGraphMetaspaceIterator;
106 friend class Klass;
107 friend class MetaDataFactory;
108 friend class Method;
109
110 static ClassLoaderData * _the_null_class_loader_data;
111
112 WeakHandle<vm_class_loader_data> _holder; // The oop that determines lifetime of this class loader
113 OopHandle _class_loader; // The instance of java/lang/ClassLoader associated with
114 // this ClassLoaderData
115
116 ClassLoaderMetaspace * volatile _metaspace; // Meta-space where meta-data defined by the
117 // classes in the class loader are allocated.
118 Mutex* _metaspace_lock; // Locks the metaspace for allocations and setup.
119 bool _unloading; // true if this class loader goes away
120 bool _is_unsafe_anonymous; // CLD is dedicated to one class and that class determines the CLDs lifecycle.
121 // For example, an unsafe anonymous class.
122
123 // Remembered sets support for the oops in the class loader data.
124 bool _modified_oops; // Card Table Equivalent (YC/CMS support)
125 bool _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
126
127 s2 _keep_alive; // if this CLD is kept alive.
128 // Used for unsafe anonymous classes and the boot class
129 // loader. _keep_alive does not need to be volatile or
130 // atomic since there is one unique CLD per unsafe anonymous class.
131
132 volatile int _claim; // non-zero if claimed, for example during GC traces.
133 // To avoid applying oop closure more than once.
134 ChunkedHandleList _handles; // Handles to constant pool arrays, Modules, etc, which
135 // have the same life cycle of the corresponding ClassLoader.
136
206
207 // The "claim" is typically used to check if oops_do needs to be applied on
208 // the CLD or not. Most GCs only perform strong marking during the marking phase.
209 enum Claim {
210 _claim_none = 0,
211 _claim_finalizable = 2,
212 _claim_strong = 3,
213 _claim_other = 4
214 };
215 void clear_claim() { _claim = 0; }
216 void clear_claim(int claim);
217 bool claimed() const { return _claim != 0; }
218 bool claimed(int claim) const { return (_claim & claim) == claim; }
219 bool try_claim(int claim);
220
221 // Computes if the CLD is alive or not. This is safe to call in concurrent
222 // contexts.
223 bool is_alive() const;
224
225 // Accessors
226 ClassLoaderMetaspace* metaspace_or_null() const { return _metaspace; }
227
228 static ClassLoaderData* the_null_class_loader_data() {
229 return _the_null_class_loader_data;
230 }
231
232 Mutex* metaspace_lock() const { return _metaspace_lock; }
233
234 bool is_unsafe_anonymous() const { return _is_unsafe_anonymous; }
235
236 static void init_null_class_loader_data();
237
238 bool is_the_null_class_loader_data() const {
239 return this == _the_null_class_loader_data;
240 }
241
242 // Returns true if this class loader data is for the system class loader.
243 // (Note that the class loader data may be unsafe anonymous.)
244 bool is_system_class_loader_data() const;
245
246 // Returns true if this class loader data is for the platform class loader.
247 // (Note that the class loader data may be unsafe anonymous.)
248 bool is_platform_class_loader_data() const;
249
250 // Returns true if this class loader data is for the boot class loader.
251 // (Note that the class loader data may be unsafe anonymous.)
252 inline bool is_boot_class_loader_data() const;
253
254 bool is_builtin_class_loader_data() const;
255 bool is_permanent_class_loader_data() const;
256
257 // The Metaspace is created lazily so may be NULL. This
258 // method will allocate a Metaspace if needed.
259 ClassLoaderMetaspace* metaspace_non_null();
260
261 inline oop class_loader() const;
262
263 // Returns true if this class loader data is for a loader going away.
264 // Note that this is only safe after the GC has computed if the CLD is
265 // unloading or not. In concurrent contexts where there are no such
266 // guarantees, is_alive() should be used instead.
267 bool is_unloading() const {
268 assert(!(is_the_null_class_loader_data() && _unloading), "The null class loader can never be unloaded");
269 return _unloading;
270 }
271
272 // Used to refcount an unsafe anonymous class's CLD in order to
273 // indicate their aliveness.
274 void inc_keep_alive();
275 void dec_keep_alive();
276
277 void initialize_holder(Handle holder);
278
279 void oops_do(OopClosure* f, int claim_value, bool clear_modified_oops = false);
|
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 #ifndef SHARE_CLASSFILE_CLASSLOADERDATA_HPP
26 #define SHARE_CLASSFILE_CLASSLOADERDATA_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/memRegion.hpp"
30 #include "oops/oopHandle.hpp"
31 #include "oops/weakHandle.hpp"
32 #include "runtime/atomic.hpp"
33 #include "runtime/mutex.hpp"
34 #include "utilities/growableArray.hpp"
35 #include "utilities/macros.hpp"
36 #if INCLUDE_JFR
37 #include "jfr/support/jfrTraceIdExtension.hpp"
38 #endif
39
40 // external name (synthetic) for the primordial "bootstrap" class loader instance
41 #define BOOTSTRAP_LOADER_NAME "bootstrap"
42 #define BOOTSTRAP_LOADER_NAME_LEN 9
43
44 //
45 // A class loader represents a linkset. Conceptually, a linkset identifies
46 // the complete transitive closure of resolved links that a dynamic linker can
47 // produce.
48 //
49 // A ClassLoaderData also encapsulates the allocation space, called a metaspace,
50 // used by the dynamic linker to allocate the runtime representation of all
51 // the types it defines.
52 //
53 // ClassLoaderData are stored in the runtime representation of classes,
54 // and provides iterators for root tracing and other GC operations.
55
56 class ClassLoaderDataGraph;
57 class JNIMethodBlock;
58 class ModuleEntry;
59 class PackageEntry;
60 class ModuleEntryTable;
61 class PackageEntryTable;
62 class DictionaryEntry;
63 class Dictionary;
64
65 namespace metaspace {
66 class ClassLoaderMetaspace;
67 }
68
69 // ClassLoaderData class
70
71 class ClassLoaderData : public CHeapObj<mtClass> {
72 friend class VMStructs;
73
74 private:
75 class ChunkedHandleList {
76 struct Chunk : public CHeapObj<mtClass> {
77 static const size_t CAPACITY = 32;
78
79 oop _data[CAPACITY];
80 volatile juint _size;
81 Chunk* _next;
82
83 Chunk(Chunk* c) : _size(0), _next(c) { }
84 };
85
86 Chunk* volatile _head;
87
88 void oops_do_chunk(OopClosure* f, Chunk* c, const juint size);
99 void oops_do(OopClosure* f);
100
101 int count() const;
102 };
103
104 friend class ClassLoaderDataGraph;
105 friend class ClassLoaderDataGraphIterator;
106 friend class ClassLoaderDataGraphKlassIteratorAtomic;
107 friend class ClassLoaderDataGraphKlassIteratorStatic;
108 friend class ClassLoaderDataGraphMetaspaceIterator;
109 friend class Klass;
110 friend class MetaDataFactory;
111 friend class Method;
112
113 static ClassLoaderData * _the_null_class_loader_data;
114
115 WeakHandle<vm_class_loader_data> _holder; // The oop that determines lifetime of this class loader
116 OopHandle _class_loader; // The instance of java/lang/ClassLoader associated with
117 // this ClassLoaderData
118
119 metaspace::ClassLoaderMetaspace* volatile _metaspace; // Meta-space where meta-data defined by the
120 // classes in the class loader are allocated.
121 Mutex* _metaspace_lock; // Locks the metaspace for allocations and setup.
122 bool _unloading; // true if this class loader goes away
123 bool _is_unsafe_anonymous; // CLD is dedicated to one class and that class determines the CLDs lifecycle.
124 // For example, an unsafe anonymous class.
125
126 // Remembered sets support for the oops in the class loader data.
127 bool _modified_oops; // Card Table Equivalent (YC/CMS support)
128 bool _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
129
130 s2 _keep_alive; // if this CLD is kept alive.
131 // Used for unsafe anonymous classes and the boot class
132 // loader. _keep_alive does not need to be volatile or
133 // atomic since there is one unique CLD per unsafe anonymous class.
134
135 volatile int _claim; // non-zero if claimed, for example during GC traces.
136 // To avoid applying oop closure more than once.
137 ChunkedHandleList _handles; // Handles to constant pool arrays, Modules, etc, which
138 // have the same life cycle of the corresponding ClassLoader.
139
209
210 // The "claim" is typically used to check if oops_do needs to be applied on
211 // the CLD or not. Most GCs only perform strong marking during the marking phase.
212 enum Claim {
213 _claim_none = 0,
214 _claim_finalizable = 2,
215 _claim_strong = 3,
216 _claim_other = 4
217 };
218 void clear_claim() { _claim = 0; }
219 void clear_claim(int claim);
220 bool claimed() const { return _claim != 0; }
221 bool claimed(int claim) const { return (_claim & claim) == claim; }
222 bool try_claim(int claim);
223
224 // Computes if the CLD is alive or not. This is safe to call in concurrent
225 // contexts.
226 bool is_alive() const;
227
228 // Accessors
229 metaspace::ClassLoaderMetaspace* metaspace_or_null() const { return _metaspace; }
230
231 static ClassLoaderData* the_null_class_loader_data() {
232 return _the_null_class_loader_data;
233 }
234
235 Mutex* metaspace_lock() const { return _metaspace_lock; }
236
237 bool is_unsafe_anonymous() const { return _is_unsafe_anonymous; }
238
239 static void init_null_class_loader_data();
240
241 bool is_the_null_class_loader_data() const {
242 return this == _the_null_class_loader_data;
243 }
244
245 // Returns true if this class loader data is for the system class loader.
246 // (Note that the class loader data may be unsafe anonymous.)
247 bool is_system_class_loader_data() const;
248
249 // Returns true if this class loader data is for the platform class loader.
250 // (Note that the class loader data may be unsafe anonymous.)
251 bool is_platform_class_loader_data() const;
252
253 // Returns true if this class loader data is for the boot class loader.
254 // (Note that the class loader data may be unsafe anonymous.)
255 inline bool is_boot_class_loader_data() const;
256
257 bool is_builtin_class_loader_data() const;
258 bool is_permanent_class_loader_data() const;
259
260 // The Metaspace is created lazily so may be NULL. This
261 // method will allocate a Metaspace if needed.
262 metaspace::ClassLoaderMetaspace* metaspace_non_null();
263
264 inline oop class_loader() const;
265
266 // Returns true if this class loader data is for a loader going away.
267 // Note that this is only safe after the GC has computed if the CLD is
268 // unloading or not. In concurrent contexts where there are no such
269 // guarantees, is_alive() should be used instead.
270 bool is_unloading() const {
271 assert(!(is_the_null_class_loader_data() && _unloading), "The null class loader can never be unloaded");
272 return _unloading;
273 }
274
275 // Used to refcount an unsafe anonymous class's CLD in order to
276 // indicate their aliveness.
277 void inc_keep_alive();
278 void dec_keep_alive();
279
280 void initialize_holder(Handle holder);
281
282 void oops_do(OopClosure* f, int claim_value, bool clear_modified_oops = false);
|