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