1 /*
2 * Copyright (c) 2003, 2017, 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 "prims/jvmtiEventController.hpp"
31 #include "runtime/thread.hpp"
32 #include "utilities/growableArray.hpp"
33
34 //
35 // Forward Declarations
36 //
37
38 class JvmtiEnvBase;
39 class JvmtiEnvThreadState;
40 class JvmtiDynamicCodeEventCollector;
41
42 enum JvmtiClassLoadKind {
43 jvmti_class_load_kind_load = 100,
44 jvmti_class_load_kind_retransform,
45 jvmti_class_load_kind_redefine
46 };
47
48 ///////////////////////////////////////////////////////////////
49 //
50 // class JvmtiEnvThreadStateIterator
51 //
52 // The only safe means of iterating through the JvmtiEnvThreadStates
53 // in a JvmtiThreadState.
54 // Note that this iteratation includes invalid environments pending
55 // deallocation -- in fact, some uses depend on this behavior.
56 //
57 class JvmtiEnvThreadStateIterator : public StackObj {
58 private:
59 JvmtiThreadState* state;
60 public:
61 JvmtiEnvThreadStateIterator(JvmtiThreadState* thread_state);
62 ~JvmtiEnvThreadStateIterator();
63 JvmtiEnvThreadState* first();
64 JvmtiEnvThreadState* next(JvmtiEnvThreadState* ets);
65 };
66
67
68 ///////////////////////////////////////////////////////////////
69 //
70 // class JvmtiThreadState
71 //
72 // The Jvmti state for each thread (across all JvmtiEnv):
73 // 1. Local table of enabled events.
74 class JvmtiThreadState : public CHeapObj<mtInternal> {
75 private:
76 friend class JvmtiEnv;
77 JavaThread *_thread;
78 bool _hide_single_stepping;
79 bool _pending_step_for_popframe;
80 bool _pending_step_for_earlyret;
81 int _hide_level;
82
83 public:
84 enum ExceptionState {
85 ES_CLEARED,
86 ES_DETECTED,
87 ES_CAUGHT
88 };
89
90 private:
91 ExceptionState _exception_state;
92
93 // Used to send class being redefined/retransformed and kind of transform
94 // info to the class file load hook event handler.
95 Klass* _class_being_redefined;
96 JvmtiClassLoadKind _class_load_kind;
97
98 // This is only valid when is_interp_only_mode() returns true
99 int _cur_stack_depth;
100
101 JvmtiThreadEventEnable _thread_event_enable;
102
103 // for support of JvmtiEnvThreadState
104 JvmtiEnvThreadState* _head_env_thread_state;
105
106 // doubly-linked linear list of active thread state
107 // needed in order to iterate the list without holding Threads_lock
108 static JvmtiThreadState *_head;
109 JvmtiThreadState *_next;
110 JvmtiThreadState *_prev;
111
112 // holds the current dynamic code event collector, NULL if no event collector in use
113 JvmtiDynamicCodeEventCollector* _dynamic_code_event_collector;
114 // holds the current vm object alloc event collector, NULL if no event collector in use
115 JvmtiVMObjectAllocEventCollector* _vm_object_alloc_event_collector;
116
117 // Should only be created by factory methods
118 JvmtiThreadState(JavaThread *thread);
119
120 friend class JvmtiEnvThreadStateIterator;
121 inline JvmtiEnvThreadState* head_env_thread_state();
122 inline void set_head_env_thread_state(JvmtiEnvThreadState* ets);
123
124 public:
125 ~JvmtiThreadState();
126
127 // is event_type enabled and usable for this thread in any enviroments?
128 bool is_enabled(jvmtiEvent event_type) {
129 return _thread_event_enable.is_enabled(event_type);
130 }
131
132 JvmtiThreadEventEnable *thread_event_enable() {
133 return &_thread_event_enable;
134 }
135
136 // Must only be called in situations where the state is for the current thread and
137 // the environment can not go away. To be safe, the returned JvmtiEnvThreadState
138 // must be used in such a way as there can be no intervening safepoints.
139 inline JvmtiEnvThreadState* env_thread_state(JvmtiEnvBase *env);
140
141 static void periodic_clean_up();
142
143 void add_env(JvmtiEnvBase *env);
144
145 // Used by the interpreter for fullspeed debugging support
146 bool is_interp_only_mode() { return _thread->is_interp_only_mode(); }
147 void enter_interp_only_mode();
148 void leave_interp_only_mode();
149
150 // access to the linked list of all JVMTI thread states
151 static JvmtiThreadState *first() {
152 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
153 return _head;
154 }
155
156 JvmtiThreadState *next() {
157 return _next;
158 }
159
160 // Current stack depth is only valid when is_interp_only_mode() returns true.
161 // These functions should only be called at a safepoint - usually called from same thread.
162 // Returns the number of Java activations on the stack.
163 int cur_stack_depth();
164 void invalidate_cur_stack_depth();
165 void incr_cur_stack_depth();
166 void decr_cur_stack_depth();
167
168 int count_frames();
169
170 inline JavaThread *get_thread() { return _thread; }
171
172 inline bool is_exception_detected() { return _exception_state == ES_DETECTED; }
173 inline bool is_exception_caught() { return _exception_state == ES_CAUGHT; }
174
175 inline void set_exception_detected() { _exception_state = ES_DETECTED; }
176 inline void set_exception_caught() { _exception_state = ES_CAUGHT; }
177
178 inline void clear_exception_state() { _exception_state = ES_CLEARED; }
179
180 // We need to save and restore exception state inside JvmtiEventMark
181 inline ExceptionState get_exception_state() { return _exception_state; }
182 inline void restore_exception_state(ExceptionState state) { _exception_state = state; }
183
184 inline void clear_hide_single_stepping() {
185 if (_hide_level > 0) {
186 _hide_level--;
187 } else {
188 assert(_hide_single_stepping, "hide_single_stepping is out of phase");
189 _hide_single_stepping = false;
190 }
191 }
192 inline bool hide_single_stepping() { return _hide_single_stepping; }
193 inline void set_hide_single_stepping() {
194 if (_hide_single_stepping) {
195 _hide_level++;
196 } else {
197 assert(_hide_level == 0, "hide_level is out of phase");
198 _hide_single_stepping = true;
199 }
200 }
201
202 // Step pending flag is set when PopFrame is called and it is cleared
203 // when step for the Pop Frame is completed.
204 // This logic is used to distinguish b/w step for pop frame and repeat step.
205 void set_pending_step_for_popframe() { _pending_step_for_popframe = true; }
206 void clr_pending_step_for_popframe() { _pending_step_for_popframe = false; }
207 bool is_pending_step_for_popframe() { return _pending_step_for_popframe; }
208 void process_pending_step_for_popframe();
209
210 // Step pending flag is set when ForceEarlyReturn is called and it is cleared
211 // when step for the ForceEarlyReturn is completed.
212 // This logic is used to distinguish b/w step for early return and repeat step.
213 void set_pending_step_for_earlyret() { _pending_step_for_earlyret = true; }
214 void clr_pending_step_for_earlyret() { _pending_step_for_earlyret = false; }
215 bool is_pending_step_for_earlyret() { return _pending_step_for_earlyret; }
216 void process_pending_step_for_earlyret();
217
218 // Setter and getter method is used to send redefined class info
219 // when class file load hook event is posted.
220 // It is set while loading redefined class and cleared before the
221 // class file load hook event is posted.
222 inline void set_class_being_redefined(Klass* k, JvmtiClassLoadKind kind) {
223 _class_being_redefined = k;
224 _class_load_kind = kind;
225 }
226
227 inline void clear_class_being_redefined() {
228 _class_being_redefined = NULL;
229 _class_load_kind = jvmti_class_load_kind_load;
230 }
231
232 inline Klass* get_class_being_redefined() {
233 return _class_being_redefined;
234 }
235
236 inline JvmtiClassLoadKind get_class_load_kind() {
237 return _class_load_kind;
238 }
239
240 // RedefineClasses support
241 // The bug 6214132 caused the verification to fail.
242 //
243 // Below is the detailed description of the fix approach taken:
244 // 1. What's done in RedefineClasses() before verification:
245 // a) A reference to the class being redefined (_the_class) and a
246 // reference to new version of the class (_scratch_class) are
247 // saved here for use during the bytecode verification phase of
248 // RedefineClasses. See RedefineVerifyMark for how these fields
249 // are managed.
250 // b) The _java_mirror field from _the_class is copied to the
251 // _java_mirror field in _scratch_class. This means that a jclass
252 // returned for _the_class or _scratch_class will refer to the
253 // same Java mirror. The verifier will see the "one true mirror"
254 // for the class being verified.
255 // 2. What is done at verification:
256 // When the verifier makes calls into the VM to ask questions about
257 // the class being verified, it will pass the jclass to JVM_* functions.
258 // The jclass is always pointing to the mirror of _the_class.
259 // ~28 JVM_* functions called by the verifier for the information
260 // about CP entries and klass structure should check the jvmtiThreadState
261 // info about equivalent klass versions and use it to replace a Klass*
262 // of _the_class with a Klass* of _scratch_class. The function
263 // class_to_verify_considering_redefinition() must be called for it.
264 //
265 // Note again, that this redirection happens only for the verifier thread.
266 // Other threads have very small overhead by checking the existence
267 // of the jvmtiThreadSate and the information about klasses equivalence.
268 // No JNI functions need to be changed, they don't reference the klass guts.
269 // The JavaThread pointer is already available in all JVM_* functions
270 // used by the verifier, so there is no extra performance issue with it.
271
272 private:
273 Klass* _the_class_for_redefinition_verification;
274 Klass* _scratch_class_for_redefinition_verification;
275
276 public:
277 inline void set_class_versions_map(Klass* the_class,
278 Klass* scratch_class) {
279 _the_class_for_redefinition_verification = the_class;
280 _scratch_class_for_redefinition_verification = scratch_class;
281 }
282
283 inline void clear_class_versions_map() { set_class_versions_map(NULL, NULL); }
284
285 static inline
286 Klass* class_to_verify_considering_redefinition(Klass* klass,
287 JavaThread *thread) {
288 JvmtiThreadState *state = thread->jvmti_thread_state();
289 if (state != NULL && state->_the_class_for_redefinition_verification != NULL) {
290 if (state->_the_class_for_redefinition_verification == klass) {
291 klass = state->_scratch_class_for_redefinition_verification;
292 }
293 }
294 return klass;
295 }
296
297 // Todo: get rid of this!
298 private:
299 bool _debuggable;
300 public:
301 // Should the thread be enumerated by jvmtiInternal::GetAllThreads?
302 bool is_debuggable() { return _debuggable; }
303 // If a thread cannot be suspended (has no valid last_java_frame) then it gets marked !debuggable
304 void set_debuggable(bool debuggable) { _debuggable = debuggable; }
305
306 public:
307
308 bool may_be_walked();
309
310 // Thread local event collector setter and getter methods.
311 JvmtiDynamicCodeEventCollector* get_dynamic_code_event_collector() {
312 return _dynamic_code_event_collector;
313 }
314 JvmtiVMObjectAllocEventCollector* get_vm_object_alloc_event_collector() {
315 return _vm_object_alloc_event_collector;
316 }
317 void set_dynamic_code_event_collector(JvmtiDynamicCodeEventCollector* collector) {
318 _dynamic_code_event_collector = collector;
319 }
320 void set_vm_object_alloc_event_collector(JvmtiVMObjectAllocEventCollector* collector) {
321 _vm_object_alloc_event_collector = collector;
322 }
323
324
325 //
326 // Frame routines
327 //
328
329 public:
330
331 // true when the thread was suspended with a pointer to the last Java frame.
332 bool has_last_frame() { return _thread->has_last_Java_frame(); }
333
334 void update_for_pop_top_frame();
335
336 // already holding JvmtiThreadState_lock - retrieve or create JvmtiThreadState
337 // Can return NULL if JavaThread is exiting.
338 static JvmtiThreadState *state_for_while_locked(JavaThread *thread);
339 // retrieve or create JvmtiThreadState
340 // Can return NULL if JavaThread is exiting.
341 static JvmtiThreadState *state_for(JavaThread *thread);
342
343 // JVMTI ForceEarlyReturn support
344
345 // This is set to earlyret_pending to signal that top Java frame
346 // should be returned immediately
347 public:
348 int _earlyret_state;
349 TosState _earlyret_tos;
350 jvalue _earlyret_value;
351 oop _earlyret_oop; // Used to return an oop result into Java code from
352 // ForceEarlyReturnObject, GC-preserved
353
354 // Setting and clearing earlyret_state
355 // earlyret_pending indicates that a ForceEarlyReturn() has been
356 // requested and not yet been completed.
357 public:
358 enum EarlyretState {
359 earlyret_inactive = 0,
360 earlyret_pending = 1
361 };
362
363 void set_earlyret_pending(void) { _earlyret_state = earlyret_pending; }
364 void clr_earlyret_pending(void) { _earlyret_state = earlyret_inactive; }
365 bool is_earlyret_pending(void) { return (_earlyret_state == earlyret_pending); }
366
367 TosState earlyret_tos() { return _earlyret_tos; }
368 oop earlyret_oop() const { return _earlyret_oop; }
369 void set_earlyret_oop (oop x) { _earlyret_oop = x; }
370 jvalue earlyret_value() { return _earlyret_value; }
371 void set_earlyret_value(jvalue val, TosState tos) { _earlyret_tos = tos; _earlyret_value = val; }
372 void clr_earlyret_value() { _earlyret_tos = ilgl; _earlyret_value.j = 0L; }
373
374 static ByteSize earlyret_state_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_state); }
375 static ByteSize earlyret_tos_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_tos); }
376 static ByteSize earlyret_oop_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_oop); }
377 static ByteSize earlyret_value_offset() { return byte_offset_of(JvmtiThreadState, _earlyret_value); }
378
379 void oops_do(OopClosure* f) NOT_JVMTI_RETURN; // GC support
380
381 public:
382 void set_should_post_on_exceptions(bool val) { _thread->set_should_post_on_exceptions_flag(val ? JNI_TRUE : JNI_FALSE); }
383 };
384
385 class RedefineVerifyMark : public StackObj {
386 private:
387 JvmtiThreadState* _state;
388 Klass* _scratch_class;
389 OopHandle _scratch_mirror;
390
391 public:
392 RedefineVerifyMark(Klass* the_class, Klass* scratch_class,
393 JvmtiThreadState *state) : _state(state), _scratch_class(scratch_class)
394 {
395 _state->set_class_versions_map(the_class, scratch_class);
396 _scratch_mirror = _scratch_class->java_mirror_handle();
397 _scratch_class->set_java_mirror_handle(the_class->java_mirror_handle());
398 }
399
400 ~RedefineVerifyMark() {
401 // Restore the scratch class's mirror, so when scratch_class is removed
402 // the correct mirror pointing to it can be cleared.
403 _scratch_class->set_java_mirror_handle(_scratch_mirror);
404 _state->clear_class_versions_map();
405 }
406 };
407
408 #endif // SHARE_VM_PRIMS_JVMTITHREADSTATE_HPP