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 #ifndef _JAVA_JVMTITHREADSTATE_H_
26 #define _JAVA_JVMTITHREADSTATE_H_
27
28 //
29 // Forward Declarations
30 //
31
32 class JvmtiEnvBase;
33 class JvmtiEnvThreadState;
34 class JvmtiDynamicCodeEventCollector;
35
36 enum JvmtiClassLoadKind {
37 jvmti_class_load_kind_load = 100,
38 jvmti_class_load_kind_retransform,
39 jvmti_class_load_kind_redefine
40 };
41
42 ///////////////////////////////////////////////////////////////
43 //
44 // class JvmtiEnvThreadStateIterator
45 //
46 // The only safe means of iterating through the JvmtiEnvThreadStates
47 // in a JvmtiThreadState.
48 // Note that this iteratation includes invalid environments pending
49 // deallocation -- in fact, some uses depend on this behavior.
50 //
51 class JvmtiEnvThreadStateIterator : public StackObj {
52 private:
53 JvmtiThreadState* state;
54 public:
55 JvmtiEnvThreadStateIterator(JvmtiThreadState* thread_state);
56 ~JvmtiEnvThreadStateIterator();
57 JvmtiEnvThreadState* first();
58 JvmtiEnvThreadState* next(JvmtiEnvThreadState* ets);
59 };
60
61
62 ///////////////////////////////////////////////////////////////
63 //
64 // class JvmtiThreadState
65 //
66 // The Jvmti state for each thread (across all JvmtiEnv):
67 // 1. Local table of enabled events.
68 class JvmtiThreadState : public CHeapObj {
69 private:
70 friend class JvmtiEnv;
71 JavaThread *_thread;
72 bool _exception_detected;
73 bool _exception_caught;
74 bool _hide_single_stepping;
75 bool _pending_step_for_popframe;
76 bool _pending_step_for_earlyret;
77 int _hide_level;
78
79 // Used to send class being redefined/retransformed and kind of transform
80 // info to the class file load hook event handler.
81 KlassHandle *_class_being_redefined;
82 JvmtiClassLoadKind _class_load_kind;
83
84 // This is only valid when is_interp_only_mode() returns true
85 int _cur_stack_depth;
86
87 JvmtiThreadEventEnable _thread_event_enable;
88
89 // for support of JvmtiEnvThreadState
90 JvmtiEnvThreadState* _head_env_thread_state;
91
92 // doubly-linked linear list of active thread state
93 // needed in order to iterate the list without holding Threads_lock
94 static JvmtiThreadState *_head;
95 JvmtiThreadState *_next;
96 JvmtiThreadState *_prev;
97
98 // holds the current dynamic code event collector, NULL if no event collector in use
99 JvmtiDynamicCodeEventCollector* _dynamic_code_event_collector;
100 // holds the current vm object alloc event collector, NULL if no event collector in use
101 JvmtiVMObjectAllocEventCollector* _vm_object_alloc_event_collector;
102
103 // Should only be created by factory methods
104 JvmtiThreadState(JavaThread *thread);
105
106 friend class JvmtiEnvThreadStateIterator;
107 inline JvmtiEnvThreadState* head_env_thread_state();
108 inline void set_head_env_thread_state(JvmtiEnvThreadState* ets);
109
110 public:
111 ~JvmtiThreadState();
112
113 // is event_type enabled and usable for this thread in any enviroments?
114 bool is_enabled(jvmtiEvent event_type) {
115 return _thread_event_enable.is_enabled(event_type);
116 }
117
118 JvmtiThreadEventEnable *thread_event_enable() {
119 return &_thread_event_enable;
120 }
121
122 // Must only be called in situations where the state is for the current thread and
123 // the environment can not go away. To be safe, the returned JvmtiEnvThreadState
124 // must be used in such a way as there can be no intervening safepoints.
125 inline JvmtiEnvThreadState* env_thread_state(JvmtiEnvBase *env);
126
127 static void periodic_clean_up();
128
129 void add_env(JvmtiEnvBase *env);
130
131 // Used by the interpreter for fullspeed debugging support
132 bool is_interp_only_mode() { return _thread->is_interp_only_mode(); }
133 void enter_interp_only_mode();
134 void leave_interp_only_mode();
135
136 // access to the linked list of all JVMTI thread states
137 static JvmtiThreadState *first() {
138 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
139 return _head;
140 }
141
142 JvmtiThreadState *next() {
143 return _next;
144 }
145
146 // Current stack depth is only valid when is_interp_only_mode() returns true.
147 // These functions should only be called at a safepoint - usually called from same thread.
148 // Returns the number of Java activations on the stack.
149 int cur_stack_depth();
150 void invalidate_cur_stack_depth();
151 void incr_cur_stack_depth();
152 void decr_cur_stack_depth();
153
154 int count_frames();
155
156 inline JavaThread *get_thread() { return _thread; }
157 inline bool is_exception_detected() { return _exception_detected; }
158 inline bool is_exception_caught() { return _exception_caught; }
159 inline void set_exception_detected() { _exception_detected = true;
160 _exception_caught = false; }
161 inline void set_exception_caught() { _exception_caught = true;
162 _exception_detected = false; }
163
164 inline void clear_hide_single_stepping() {
165 if (_hide_level > 0) {
166 _hide_level--;
167 } else {
168 assert(_hide_single_stepping, "hide_single_stepping is out of phase");
169 _hide_single_stepping = false;
170 }
171 }
172 inline bool hide_single_stepping() { return _hide_single_stepping; }
173 inline void set_hide_single_stepping() {
174 if (_hide_single_stepping) {
175 _hide_level++;
176 } else {
177 assert(_hide_level == 0, "hide_level is out of phase");
178 _hide_single_stepping = true;
179 }
180 }
181
182 // Step pending flag is set when PopFrame is called and it is cleared
183 // when step for the Pop Frame is completed.
184 // This logic is used to distinguish b/w step for pop frame and repeat step.
185 void set_pending_step_for_popframe() { _pending_step_for_popframe = true; }
186 void clr_pending_step_for_popframe() { _pending_step_for_popframe = false; }
187 bool is_pending_step_for_popframe() { return _pending_step_for_popframe; }
188 void process_pending_step_for_popframe();
189
190 // Step pending flag is set when ForceEarlyReturn is called and it is cleared
191 // when step for the ForceEarlyReturn is completed.
192 // This logic is used to distinguish b/w step for early return and repeat step.
193 void set_pending_step_for_earlyret() { _pending_step_for_earlyret = true; }
194 void clr_pending_step_for_earlyret() { _pending_step_for_earlyret = false; }
195 bool is_pending_step_for_earlyret() { return _pending_step_for_earlyret; }
196 void process_pending_step_for_earlyret();
197
198 // Setter and getter method is used to send redefined class info
199 // when class file load hook event is posted.
200 // It is set while loading redefined class and cleared before the
201 // class file load hook event is posted.
202 inline void set_class_being_redefined(KlassHandle *h_class, JvmtiClassLoadKind kind) {
203 _class_being_redefined = h_class;
204 _class_load_kind = kind;
205 }
206
207 inline void clear_class_being_redefined() {
208 _class_being_redefined = NULL;
209 _class_load_kind = jvmti_class_load_kind_load;
210 }
211
212 inline KlassHandle *get_class_being_redefined() {
213 return _class_being_redefined;
214 }
215
216 inline JvmtiClassLoadKind get_class_load_kind() {
217 return _class_load_kind;
218 }
219
220 // RedefineClasses support
221 // The bug 6214132 caused the verification to fail.
222 //
223 // Below is the detailed description of the fix approach taken:
224 // 1. What's done in RedefineClasses() before verification:
225 // a) A reference to the class being redefined (_the_class) and a
226 // reference to new version of the class (_scratch_class) are
227 // saved here for use during the bytecode verification phase of
228 // RedefineClasses. See RedefineVerifyMark for how these fields
229 // are managed.
230 // b) The _java_mirror field from _the_class is copied to the
231 // _java_mirror field in _scratch_class. This means that a jclass
232 // returned for _the_class or _scratch_class will refer to the
233 // same Java mirror. The verifier will see the "one true mirror"
234 // for the class being verified.
235 // 2. What is done at verification:
236 // When the verifier makes calls into the VM to ask questions about
237 // the class being verified, it will pass the jclass to JVM_* functions.
238 // The jclass is always pointing to the mirror of _the_class.
239 // ~28 JVM_* functions called by the verifier for the information
240 // about CP entries and klass structure should check the jvmtiThreadState
241 // info about equivalent klass versions and use it to replace a klassOop
242 // of _the_class with a klassOop of _scratch_class. The function
243 // class_to_verify_considering_redefinition() must be called for it.
244 //
245 // Note again, that this redirection happens only for the verifier thread.
246 // Other threads have very small overhead by checking the existence
247 // of the jvmtiThreadSate and the information about klasses equivalence.
248 // No JNI functions need to be changed, they don't reference the klass guts.
249 // The JavaThread pointer is already available in all JVM_* functions
250 // used by the verifier, so there is no extra performance issue with it.
251
252 private:
253 KlassHandle *_the_class_for_redefinition_verification;
254 KlassHandle *_scratch_class_for_redefinition_verification;
255
256 public:
257 inline void set_class_versions_map(KlassHandle *the_class,
258 KlassHandle *scratch_class) {
259 _the_class_for_redefinition_verification = the_class;
260 _scratch_class_for_redefinition_verification = scratch_class;
261 }
262
263 inline void clear_class_versions_map() { set_class_versions_map(NULL, NULL); }
264
265 static inline
266 klassOop class_to_verify_considering_redefinition(klassOop klass,
267 JavaThread *thread) {
268 JvmtiThreadState *state = thread->jvmti_thread_state();
269 if (state != NULL && state->_the_class_for_redefinition_verification != NULL) {
270 if ((*(state->_the_class_for_redefinition_verification))() == klass) {
271 klass = (*(state->_scratch_class_for_redefinition_verification))();
272 }
273 }
274 return klass;
275 }
276
277 // Todo: get rid of this!
278 private:
279 bool _debuggable;
280 public:
281 // Should the thread be enumerated by jvmtiInternal::GetAllThreads?
282 bool is_debuggable() { return _debuggable; }
283 // If a thread cannot be suspended (has no valid last_java_frame) then it gets marked !debuggable
284 void set_debuggable(bool debuggable) { _debuggable = debuggable; }
285
286 public:
287
288 bool may_be_walked();
289
290 // Thread local event collector setter and getter methods.
291 JvmtiDynamicCodeEventCollector* get_dynamic_code_event_collector() {
292 return _dynamic_code_event_collector;
293 }
294 JvmtiVMObjectAllocEventCollector* get_vm_object_alloc_event_collector() {
295 return _vm_object_alloc_event_collector;
296 }
297 void set_dynamic_code_event_collector(JvmtiDynamicCodeEventCollector* collector) {
298 _dynamic_code_event_collector = collector;
299 }
300 void set_vm_object_alloc_event_collector(JvmtiVMObjectAllocEventCollector* collector) {
301 _vm_object_alloc_event_collector = collector;
302 }
303
304
305 //
306 // Frame routines
307 //
308
309 public:
310
311 // true when the thread was suspended with a pointer to the last Java frame.
312 bool has_last_frame() { return _thread->has_last_Java_frame(); }
313
314 void update_for_pop_top_frame();
315
316 // already holding JvmtiThreadState_lock - retrieve or create JvmtiThreadState
317 // Can return NULL if JavaThread is exiting.
318 inline static JvmtiThreadState *state_for_while_locked(JavaThread *thread) {
319 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
320
321 JvmtiThreadState *state = thread->jvmti_thread_state();
322 if (state == NULL) {
323 if (thread->is_exiting()) {
324 // don't add a JvmtiThreadState to a thread that is exiting
325 return NULL;
326 }
327
328 state = new JvmtiThreadState(thread);
329 }
330 return state;
331 }
332
333 // retrieve or create JvmtiThreadState
334 // Can return NULL if JavaThread is exiting.
335 inline static JvmtiThreadState *state_for(JavaThread *thread) {
336 JvmtiThreadState *state = thread->jvmti_thread_state();
337 if (state == NULL) {
338 MutexLocker mu(JvmtiThreadState_lock);
339 // check again with the lock held
340 state = state_for_while_locked(thread);
341 } else {
342 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
343 }
344 return state;
345 }
346
347 // JVMTI ForceEarlyReturn support
348
349 // This is set to earlyret_pending to signal that top Java frame
350 // should be returned immediately
351 public:
352 int _earlyret_state;
353 TosState _earlyret_tos;
354 jvalue _earlyret_value;
355 oop _earlyret_oop; // Used to return an oop result into Java code from
356 // ForceEarlyReturnObject, GC-preserved
357
358 // Setting and clearing earlyret_state
359 // earlyret_pending indicates that a ForceEarlyReturn() has been
360 // requested and not yet been completed.
361 public:
362 enum EarlyretState {
363 earlyret_inactive = 0,
364 earlyret_pending = 1
365 };
366
367 void set_earlyret_pending(void) { _earlyret_state = earlyret_pending; }
368 void clr_earlyret_pending(void) { _earlyret_state = earlyret_inactive; }
369 bool is_earlyret_pending(void) { return (_earlyret_state == earlyret_pending); }
370
371 TosState earlyret_tos() { return _earlyret_tos; }
372 oop earlyret_oop() const { return _earlyret_oop; }
373 void set_earlyret_oop (oop x) { _earlyret_oop = x; }
374 jvalue earlyret_value() { return _earlyret_value; }
375 void set_earlyret_value(jvalue val, TosState tos) { _earlyret_tos = tos; _earlyret_value = val; }
376 void clr_earlyret_value() { _earlyret_tos = ilgl; _earlyret_value.j = 0L; }
377
378 static ByteSize earlyret_state_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_state); }
379 static ByteSize earlyret_tos_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_tos); }
380 static ByteSize earlyret_oop_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_oop); }
381 static ByteSize earlyret_value_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_value); }
382
383 void oops_do(OopClosure* f); // GC support
384
385 public:
386 void set_should_post_on_exceptions(bool val) { _thread->set_should_post_on_exceptions_flag(val ? JNI_TRUE : JNI_FALSE); }
387 };
388
389 class RedefineVerifyMark : public StackObj {
390 private:
391 JvmtiThreadState *_state;
392
393 public:
394 RedefineVerifyMark(KlassHandle *the_class, KlassHandle *scratch_class,
395 JvmtiThreadState *state) : _state(state)
396 {
397 _state->set_class_versions_map(the_class, scratch_class);
398 (*scratch_class)->set_java_mirror((*the_class)->java_mirror());
399 }
400
401 ~RedefineVerifyMark() {
402 _state->clear_class_versions_map();
403 }
404 };
405
406 #endif /* _JAVA_JVMTITHREADSTATE_H_ */