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