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 //
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 {
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 set_exception_caught() { _exception_caught = true;
169 _exception_detected = false; }
170
171 inline void clear_hide_single_stepping() {
172 if (_hide_level > 0) {
173 _hide_level--;
174 } else {
175 assert(_hide_single_stepping, "hide_single_stepping is out of phase");
176 _hide_single_stepping = false;
177 }
178 }
179 inline bool hide_single_stepping() { return _hide_single_stepping; }
180 inline void set_hide_single_stepping() {
181 if (_hide_single_stepping) {
182 _hide_level++;
183 } else {
184 assert(_hide_level == 0, "hide_level is out of phase");
185 _hide_single_stepping = true;
186 }
187 }
188
189 // Step pending flag is set when PopFrame is called and it is cleared
190 // when step for the Pop Frame is completed.
191 // This logic is used to distinguish b/w step for pop frame and repeat step.
192 void set_pending_step_for_popframe() { _pending_step_for_popframe = true; }
193 void clr_pending_step_for_popframe() { _pending_step_for_popframe = false; }
194 bool is_pending_step_for_popframe() { return _pending_step_for_popframe; }
195 void process_pending_step_for_popframe();
196
197 // Step pending flag is set when ForceEarlyReturn is called and it is cleared
198 // when step for the ForceEarlyReturn is completed.
199 // This logic is used to distinguish b/w step for early return and repeat step.
200 void set_pending_step_for_earlyret() { _pending_step_for_earlyret = true; }
201 void clr_pending_step_for_earlyret() { _pending_step_for_earlyret = false; }
202 bool is_pending_step_for_earlyret() { return _pending_step_for_earlyret; }
203 void process_pending_step_for_earlyret();
204
205 // Setter and getter method is used to send redefined class info
206 // when class file load hook event is posted.
207 // It is set while loading redefined class and cleared before the
208 // class file load hook event is posted.
209 inline void set_class_being_redefined(KlassHandle *h_class, JvmtiClassLoadKind kind) {
210 _class_being_redefined = h_class;
211 _class_load_kind = kind;
212 }
213
214 inline void clear_class_being_redefined() {
215 _class_being_redefined = NULL;
216 _class_load_kind = jvmti_class_load_kind_load;
217 }
218
219 inline KlassHandle *get_class_being_redefined() {
220 return _class_being_redefined;
221 }
222
223 inline JvmtiClassLoadKind get_class_load_kind() {
224 return _class_load_kind;
225 }
226
227 // RedefineClasses support
228 // The bug 6214132 caused the verification to fail.
229 //
230 // Below is the detailed description of the fix approach taken:
231 // 1. What's done in RedefineClasses() before verification:
232 // a) A reference to the class being redefined (_the_class) and a
233 // reference to new version of the class (_scratch_class) are
234 // saved here for use during the bytecode verification phase of
235 // RedefineClasses. See RedefineVerifyMark for how these fields
236 // are managed.
237 // b) The _java_mirror field from _the_class is copied to the
238 // _java_mirror field in _scratch_class. This means that a jclass
239 // returned for _the_class or _scratch_class will refer to the
240 // same Java mirror. The verifier will see the "one true mirror"
241 // for the class being verified.
242 // 2. What is done at verification:
243 // When the verifier makes calls into the VM to ask questions about
244 // the class being verified, it will pass the jclass to JVM_* functions.
245 // The jclass is always pointing to the mirror of _the_class.
246 // ~28 JVM_* functions called by the verifier for the information
247 // about CP entries and klass structure should check the jvmtiThreadState
248 // info about equivalent klass versions and use it to replace a klassOop
249 // of _the_class with a klassOop of _scratch_class. The function
250 // class_to_verify_considering_redefinition() must be called for it.
251 //
252 // Note again, that this redirection happens only for the verifier thread.
253 // Other threads have very small overhead by checking the existence
254 // of the jvmtiThreadSate and the information about klasses equivalence.
255 // No JNI functions need to be changed, they don't reference the klass guts.
256 // The JavaThread pointer is already available in all JVM_* functions
257 // used by the verifier, so there is no extra performance issue with it.
258
259 private:
260 KlassHandle *_the_class_for_redefinition_verification;
261 KlassHandle *_scratch_class_for_redefinition_verification;
262
263 public:
264 inline void set_class_versions_map(KlassHandle *the_class,
265 KlassHandle *scratch_class) {
266 _the_class_for_redefinition_verification = the_class;
267 _scratch_class_for_redefinition_verification = scratch_class;
268 }
269
270 inline void clear_class_versions_map() { set_class_versions_map(NULL, NULL); }
271
272 static inline
273 klassOop class_to_verify_considering_redefinition(klassOop klass,
274 JavaThread *thread) {
275 JvmtiThreadState *state = thread->jvmti_thread_state();
276 if (state != NULL && state->_the_class_for_redefinition_verification != NULL) {
277 if ((*(state->_the_class_for_redefinition_verification))() == klass) {
278 klass = (*(state->_scratch_class_for_redefinition_verification))();
279 }
280 }
281 return klass;
282 }
283
284 // Todo: get rid of this!
285 private:
286 bool _debuggable;
287 public:
288 // Should the thread be enumerated by jvmtiInternal::GetAllThreads?
289 bool is_debuggable() { return _debuggable; }
290 // If a thread cannot be suspended (has no valid last_java_frame) then it gets marked !debuggable
291 void set_debuggable(bool debuggable) { _debuggable = debuggable; }
292
293 public:
294
295 bool may_be_walked();
296
297 // Thread local event collector setter and getter methods.
298 JvmtiDynamicCodeEventCollector* get_dynamic_code_event_collector() {
299 return _dynamic_code_event_collector;
300 }
301 JvmtiVMObjectAllocEventCollector* get_vm_object_alloc_event_collector() {
302 return _vm_object_alloc_event_collector;
303 }
304 void set_dynamic_code_event_collector(JvmtiDynamicCodeEventCollector* collector) {
305 _dynamic_code_event_collector = collector;
306 }
307 void set_vm_object_alloc_event_collector(JvmtiVMObjectAllocEventCollector* collector) {
308 _vm_object_alloc_event_collector = collector;
309 }
310
311
312 //
313 // Frame routines
314 //
315
316 public:
317
318 // true when the thread was suspended with a pointer to the last Java frame.
319 bool has_last_frame() { return _thread->has_last_Java_frame(); }
320
321 void update_for_pop_top_frame();
322
323 // already holding JvmtiThreadState_lock - retrieve or create JvmtiThreadState
324 // Can return NULL if JavaThread is exiting.
325 inline static JvmtiThreadState *state_for_while_locked(JavaThread *thread) {
326 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
327
328 JvmtiThreadState *state = thread->jvmti_thread_state();
329 if (state == NULL) {
330 if (thread->is_exiting()) {
331 // don't add a JvmtiThreadState to a thread that is exiting
332 return NULL;
333 }
334
335 state = new JvmtiThreadState(thread);
336 }
337 return state;
338 }
339
340 // retrieve or create JvmtiThreadState
341 // Can return NULL if JavaThread is exiting.
342 inline static JvmtiThreadState *state_for(JavaThread *thread) {
343 JvmtiThreadState *state = thread->jvmti_thread_state();
344 if (state == NULL) {
345 MutexLocker mu(JvmtiThreadState_lock);
346 // check again with the lock held
347 state = state_for_while_locked(thread);
348 } else {
349 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
350 }
351 return state;
352 }
353
354 // JVMTI ForceEarlyReturn support
355
356 // This is set to earlyret_pending to signal that top Java frame
357 // should be returned immediately
358 public:
359 int _earlyret_state;
360 TosState _earlyret_tos;
361 jvalue _earlyret_value;
362 oop _earlyret_oop; // Used to return an oop result into Java code from
363 // ForceEarlyReturnObject, GC-preserved
364
365 // Setting and clearing earlyret_state
366 // earlyret_pending indicates that a ForceEarlyReturn() has been
367 // requested and not yet been completed.
368 public:
369 enum EarlyretState {
370 earlyret_inactive = 0,
371 earlyret_pending = 1
372 };
373
374 void set_earlyret_pending(void) { _earlyret_state = earlyret_pending; }
375 void clr_earlyret_pending(void) { _earlyret_state = earlyret_inactive; }
376 bool is_earlyret_pending(void) { return (_earlyret_state == earlyret_pending); }
377
378 TosState earlyret_tos() { return _earlyret_tos; }
379 oop earlyret_oop() const { return _earlyret_oop; }
380 void set_earlyret_oop (oop x) { _earlyret_oop = x; }
381 jvalue earlyret_value() { return _earlyret_value; }
382 void set_earlyret_value(jvalue val, TosState tos) { _earlyret_tos = tos; _earlyret_value = val; }
383 void clr_earlyret_value() { _earlyret_tos = ilgl; _earlyret_value.j = 0L; }
384
385 static ByteSize earlyret_state_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_state); }
386 static ByteSize earlyret_tos_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_tos); }
387 static ByteSize earlyret_oop_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_oop); }
388 static ByteSize earlyret_value_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_value); }
389
390 void oops_do(OopClosure* f); // GC support
391
392 public:
393 void set_should_post_on_exceptions(bool val) { _thread->set_should_post_on_exceptions_flag(val ? JNI_TRUE : JNI_FALSE); }
394 };
395
396 class RedefineVerifyMark : public StackObj {
397 private:
398 JvmtiThreadState *_state;
399
400 public:
401 RedefineVerifyMark(KlassHandle *the_class, KlassHandle *scratch_class,
402 JvmtiThreadState *state) : _state(state)
403 {
404 _state->set_class_versions_map(the_class, scratch_class);
405 (*scratch_class)->set_java_mirror((*the_class)->java_mirror());
406 }
407
408 ~RedefineVerifyMark() {
409 _state->clear_class_versions_map();
410 }
411 };
412
413 #endif // SHARE_VM_PRIMS_JVMTITHREADSTATE_HPP