1 /*
2 * Copyright (c) 2003, 2012, 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 SHARE_VM_PRIMS_JVMTITHREADSTATE_HPP
26 #define SHARE_VM_PRIMS_JVMTITHREADSTATE_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "memory/allocation.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "prims/jvmtiEventController.hpp"
32 #include "runtime/thread.hpp"
33 #include "utilities/growableArray.hpp"
34
35 //
36 // Forward Declarations
37 //
38
39 class JvmtiEnvBase;
40 class JvmtiEnvThreadState;
41 class JvmtiDynamicCodeEventCollector;
42
43 enum JvmtiClassLoadKind {
44 jvmti_class_load_kind_load = 100,
45 jvmti_class_load_kind_retransform,
46 jvmti_class_load_kind_redefine
47 };
48
49 ///////////////////////////////////////////////////////////////
50 //
51 // class JvmtiEnvThreadStateIterator
52 //
53 // The only safe means of iterating through the JvmtiEnvThreadStates
54 // in a JvmtiThreadState.
55 // Note that this iteratation includes invalid environments pending
56 // deallocation -- in fact, some uses depend on this behavior.
57 //
58 class JvmtiEnvThreadStateIterator : public StackObj {
59 private:
60 JvmtiThreadState* state;
61 public:
62 JvmtiEnvThreadStateIterator(JvmtiThreadState* thread_state);
63 ~JvmtiEnvThreadStateIterator();
64 JvmtiEnvThreadState* first();
65 JvmtiEnvThreadState* next(JvmtiEnvThreadState* ets);
66 };
67
68
69 ///////////////////////////////////////////////////////////////
70 //
71 // class JvmtiThreadState
72 //
73 // The Jvmti state for each thread (across all JvmtiEnv):
74 // 1. Local table of enabled events.
75 class JvmtiThreadState : public CHeapObj<mtInternal> {
76 private:
77 friend class JvmtiEnv;
78 JavaThread *_thread;
79 bool _hide_single_stepping;
80 bool _pending_step_for_popframe;
81 bool _pending_step_for_earlyret;
82 int _hide_level;
83
84 public:
85 enum ExceptionState {
86 ES_CLEARED,
87 ES_DETECTED,
88 ES_CAUGHT
89 };
90
91 private:
92 ExceptionState _exception_state;
93
94 // Used to send class being redefined/retransformed and kind of transform
95 // info to the class file load hook event handler.
96 KlassHandle *_class_being_redefined;
97 JvmtiClassLoadKind _class_load_kind;
98
99 // This is only valid when is_interp_only_mode() returns true
100 int _cur_stack_depth;
101
102 JvmtiThreadEventEnable _thread_event_enable;
103
104 // for support of JvmtiEnvThreadState
105 JvmtiEnvThreadState* _head_env_thread_state;
106
107 // doubly-linked linear list of active thread state
108 // needed in order to iterate the list without holding Threads_lock
109 static JvmtiThreadState *_head;
110 JvmtiThreadState *_next;
111 JvmtiThreadState *_prev;
112
113 // holds the current dynamic code event collector, NULL if no event collector in use
114 JvmtiDynamicCodeEventCollector* _dynamic_code_event_collector;
115 // holds the current vm object alloc event collector, NULL if no event collector in use
116 JvmtiVMObjectAllocEventCollector* _vm_object_alloc_event_collector;
117
118 // Should only be created by factory methods
119 JvmtiThreadState(JavaThread *thread);
120
121 friend class JvmtiEnvThreadStateIterator;
122 inline JvmtiEnvThreadState* head_env_thread_state();
123 inline void set_head_env_thread_state(JvmtiEnvThreadState* ets);
124
125 public:
126 ~JvmtiThreadState();
127
128 // is event_type enabled and usable for this thread in any enviroments?
129 bool is_enabled(jvmtiEvent event_type) {
130 return _thread_event_enable.is_enabled(event_type);
131 }
132
133 JvmtiThreadEventEnable *thread_event_enable() {
134 return &_thread_event_enable;
135 }
136
137 // Must only be called in situations where the state is for the current thread and
138 // the environment can not go away. To be safe, the returned JvmtiEnvThreadState
139 // must be used in such a way as there can be no intervening safepoints.
140 inline JvmtiEnvThreadState* env_thread_state(JvmtiEnvBase *env);
141
142 static void periodic_clean_up();
143
144 void add_env(JvmtiEnvBase *env);
145
146 // Used by the interpreter for fullspeed debugging support
147 bool is_interp_only_mode() { return _thread->is_interp_only_mode(); }
148 void enter_interp_only_mode();
149 void leave_interp_only_mode();
150
151 // access to the linked list of all JVMTI thread states
152 static JvmtiThreadState *first() {
153 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
154 return _head;
155 }
156
157 JvmtiThreadState *next() {
158 return _next;
159 }
160
161 // Current stack depth is only valid when is_interp_only_mode() returns true.
162 // These functions should only be called at a safepoint - usually called from same thread.
163 // Returns the number of Java activations on the stack.
164 int cur_stack_depth();
165 void invalidate_cur_stack_depth();
166 void incr_cur_stack_depth();
167 void decr_cur_stack_depth();
168
169 int count_frames();
170
171 inline JavaThread *get_thread() { return _thread; }
172
173 inline bool is_exception_detected() { return _exception_state == ES_DETECTED; }
174 inline bool is_exception_caught() { return _exception_state == ES_CAUGHT; }
175
176 inline void set_exception_detected() { _exception_state = ES_DETECTED; }
177 inline void set_exception_caught() { _exception_state = ES_CAUGHT; }
178
179 inline void clear_exception_state() { _exception_state = ES_CLEARED; }
180
181 // We need to save and restore exception state inside JvmtiEventMark
182 inline void save_exception_state(ExceptionState *state) { *state = _exception_state; }
183 inline void restore_exception_state(ExceptionState state) { _exception_state = state; }
184
185 inline void clear_hide_single_stepping() {
186 if (_hide_level > 0) {
187 _hide_level--;
188 } else {
189 assert(_hide_single_stepping, "hide_single_stepping is out of phase");
190 _hide_single_stepping = false;
191 }
192 }
193 inline bool hide_single_stepping() { return _hide_single_stepping; }
194 inline void set_hide_single_stepping() {
195 if (_hide_single_stepping) {
196 _hide_level++;
197 } else {
198 assert(_hide_level == 0, "hide_level is out of phase");
199 _hide_single_stepping = true;
200 }
201 }
202
203 // Step pending flag is set when PopFrame is called and it is cleared
204 // when step for the Pop Frame is completed.
205 // This logic is used to distinguish b/w step for pop frame and repeat step.
206 void set_pending_step_for_popframe() { _pending_step_for_popframe = true; }
207 void clr_pending_step_for_popframe() { _pending_step_for_popframe = false; }
208 bool is_pending_step_for_popframe() { return _pending_step_for_popframe; }
209 void process_pending_step_for_popframe();
210
211 // Step pending flag is set when ForceEarlyReturn is called and it is cleared
212 // when step for the ForceEarlyReturn is completed.
213 // This logic is used to distinguish b/w step for early return and repeat step.
214 void set_pending_step_for_earlyret() { _pending_step_for_earlyret = true; }
215 void clr_pending_step_for_earlyret() { _pending_step_for_earlyret = false; }
216 bool is_pending_step_for_earlyret() { return _pending_step_for_earlyret; }
217 void process_pending_step_for_earlyret();
218
219 // Setter and getter method is used to send redefined class info
220 // when class file load hook event is posted.
221 // It is set while loading redefined class and cleared before the
222 // class file load hook event is posted.
223 inline void set_class_being_redefined(KlassHandle *h_class, JvmtiClassLoadKind kind) {
224 _class_being_redefined = h_class;
225 _class_load_kind = kind;
226 }
227
228 inline void clear_class_being_redefined() {
229 _class_being_redefined = NULL;
230 _class_load_kind = jvmti_class_load_kind_load;
231 }
232
233 inline KlassHandle *get_class_being_redefined() {
234 return _class_being_redefined;
235 }
236
237 inline JvmtiClassLoadKind get_class_load_kind() {
238 return _class_load_kind;
239 }
240
241 // RedefineClasses support
242 // The bug 6214132 caused the verification to fail.
243 //
244 // Below is the detailed description of the fix approach taken:
245 // 1. What's done in RedefineClasses() before verification:
246 // a) A reference to the class being redefined (_the_class) and a
247 // reference to new version of the class (_scratch_class) are
248 // saved here for use during the bytecode verification phase of
249 // RedefineClasses. See RedefineVerifyMark for how these fields
250 // are managed.
251 // b) The _java_mirror field from _the_class is copied to the
252 // _java_mirror field in _scratch_class. This means that a jclass
253 // returned for _the_class or _scratch_class will refer to the
254 // same Java mirror. The verifier will see the "one true mirror"
255 // for the class being verified.
256 // 2. What is done at verification:
257 // When the verifier makes calls into the VM to ask questions about
258 // the class being verified, it will pass the jclass to JVM_* functions.
259 // The jclass is always pointing to the mirror of _the_class.
260 // ~28 JVM_* functions called by the verifier for the information
261 // about CP entries and klass structure should check the jvmtiThreadState
262 // info about equivalent klass versions and use it to replace a Klass*
263 // of _the_class with a Klass* of _scratch_class. The function
264 // class_to_verify_considering_redefinition() must be called for it.
265 //
266 // Note again, that this redirection happens only for the verifier thread.
267 // Other threads have very small overhead by checking the existence
268 // of the jvmtiThreadSate and the information about klasses equivalence.
269 // No JNI functions need to be changed, they don't reference the klass guts.
270 // The JavaThread pointer is already available in all JVM_* functions
271 // used by the verifier, so there is no extra performance issue with it.
272
273 private:
274 KlassHandle *_the_class_for_redefinition_verification;
275 KlassHandle *_scratch_class_for_redefinition_verification;
276
277 public:
278 inline void set_class_versions_map(KlassHandle *the_class,
279 KlassHandle *scratch_class) {
280 _the_class_for_redefinition_verification = the_class;
281 _scratch_class_for_redefinition_verification = scratch_class;
282 }
283
284 inline void clear_class_versions_map() { set_class_versions_map(NULL, NULL); }
285
286 static inline
287 Klass* class_to_verify_considering_redefinition(Klass* klass,
288 JavaThread *thread) {
289 JvmtiThreadState *state = thread->jvmti_thread_state();
290 if (state != NULL && state->_the_class_for_redefinition_verification != NULL) {
291 if ((*(state->_the_class_for_redefinition_verification))() == klass) {
292 klass = (*(state->_scratch_class_for_redefinition_verification))();
293 }
294 }
295 return klass;
296 }
297
298 // Todo: get rid of this!
299 private:
300 bool _debuggable;
301 public:
302 // Should the thread be enumerated by jvmtiInternal::GetAllThreads?
303 bool is_debuggable() { return _debuggable; }
304 // If a thread cannot be suspended (has no valid last_java_frame) then it gets marked !debuggable
305 void set_debuggable(bool debuggable) { _debuggable = debuggable; }
306
307 public:
308
309 bool may_be_walked();
310
311 // Thread local event collector setter and getter methods.
312 JvmtiDynamicCodeEventCollector* get_dynamic_code_event_collector() {
313 return _dynamic_code_event_collector;
314 }
315 JvmtiVMObjectAllocEventCollector* get_vm_object_alloc_event_collector() {
316 return _vm_object_alloc_event_collector;
317 }
318 void set_dynamic_code_event_collector(JvmtiDynamicCodeEventCollector* collector) {
319 _dynamic_code_event_collector = collector;
320 }
321 void set_vm_object_alloc_event_collector(JvmtiVMObjectAllocEventCollector* collector) {
322 _vm_object_alloc_event_collector = collector;
323 }
324
325
326 //
327 // Frame routines
328 //
329
330 public:
331
332 // true when the thread was suspended with a pointer to the last Java frame.
333 bool has_last_frame() { return _thread->has_last_Java_frame(); }
334
335 void update_for_pop_top_frame();
336
337 // already holding JvmtiThreadState_lock - retrieve or create JvmtiThreadState
338 // Can return NULL if JavaThread is exiting.
339 inline static JvmtiThreadState *state_for_while_locked(JavaThread *thread) {
340 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
341
342 JvmtiThreadState *state = thread->jvmti_thread_state();
343 if (state == NULL) {
344 if (thread->is_exiting()) {
345 // don't add a JvmtiThreadState to a thread that is exiting
346 return NULL;
347 }
348
349 state = new JvmtiThreadState(thread);
350 }
351 return state;
352 }
353
354 // retrieve or create JvmtiThreadState
355 // Can return NULL if JavaThread is exiting.
356 inline static JvmtiThreadState *state_for(JavaThread *thread) {
357 JvmtiThreadState *state = thread->jvmti_thread_state();
358 if (state == NULL) {
359 MutexLocker mu(JvmtiThreadState_lock);
360 // check again with the lock held
361 state = state_for_while_locked(thread);
362 } else {
363 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
364 }
365 return state;
366 }
367
368 // JVMTI ForceEarlyReturn support
369
370 // This is set to earlyret_pending to signal that top Java frame
371 // should be returned immediately
372 public:
373 int _earlyret_state;
374 TosState _earlyret_tos;
375 jvalue _earlyret_value;
376 oop _earlyret_oop; // Used to return an oop result into Java code from
377 // ForceEarlyReturnObject, GC-preserved
378
379 // Setting and clearing earlyret_state
380 // earlyret_pending indicates that a ForceEarlyReturn() has been
381 // requested and not yet been completed.
382 public:
383 enum EarlyretState {
384 earlyret_inactive = 0,
385 earlyret_pending = 1
386 };
387
388 void set_earlyret_pending(void) { _earlyret_state = earlyret_pending; }
389 void clr_earlyret_pending(void) { _earlyret_state = earlyret_inactive; }
390 bool is_earlyret_pending(void) { return (_earlyret_state == earlyret_pending); }
391
392 TosState earlyret_tos() { return _earlyret_tos; }
393 oop earlyret_oop() const { return _earlyret_oop; }
394 void set_earlyret_oop (oop x) { _earlyret_oop = x; }
395 jvalue earlyret_value() { return _earlyret_value; }
396 void set_earlyret_value(jvalue val, TosState tos) { _earlyret_tos = tos; _earlyret_value = val; }
397 void clr_earlyret_value() { _earlyret_tos = ilgl; _earlyret_value.j = 0L; }
398
399 static ByteSize earlyret_state_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_state); }
400 static ByteSize earlyret_tos_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_tos); }
401 static ByteSize earlyret_oop_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_oop); }
402 static ByteSize earlyret_value_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_value); }
403
404 void oops_do(OopClosure* f) NOT_JVMTI_RETURN; // GC support
405
406 public:
407 void set_should_post_on_exceptions(bool val) { _thread->set_should_post_on_exceptions_flag(val ? JNI_TRUE : JNI_FALSE); }
408 };
409
410 class RedefineVerifyMark : public StackObj {
411 private:
412 JvmtiThreadState *_state;
413 KlassHandle _scratch_class;
414 Handle _scratch_mirror;
415
416 public:
417 RedefineVerifyMark(KlassHandle *the_class, KlassHandle *scratch_class,
418 JvmtiThreadState *state) : _state(state), _scratch_class(*scratch_class)
419 {
420 _state->set_class_versions_map(the_class, scratch_class);
421 _scratch_mirror = Handle(_scratch_class->java_mirror());
422 (*scratch_class)->set_java_mirror((*the_class)->java_mirror());
423 }
424
425 ~RedefineVerifyMark() {
426 // Restore the scratch class's mirror, so when scratch_class is removed
427 // the correct mirror pointing to it can be cleared.
428 _scratch_class->set_java_mirror(_scratch_mirror());
429 _state->clear_class_versions_map();
430 }
431 };
432
433 #endif // SHARE_VM_PRIMS_JVMTITHREADSTATE_HPP