1 /*
2 * Copyright (c) 2003, 2006, 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 # include "incls/_precompiled.incl"
26 # include "incls/_jvmtiThreadState.cpp.incl"
27
28 // marker for when the stack depth has been reset and is now unknown.
29 // any negative number would work but small ones might obscure an
30 // underrun error.
31 static const int UNKNOWN_STACK_DEPTH = -99;
32
33 ///////////////////////////////////////////////////////////////
34 //
35 // class JvmtiThreadState
36 //
37 // Instances of JvmtiThreadState hang off of each thread.
38 // Thread local storage for JVMTI.
39 //
40
41 JvmtiThreadState *JvmtiThreadState::_head = NULL;
42
43 JvmtiThreadState::JvmtiThreadState(JavaThread* thread)
44 : _thread_event_enable() {
45 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
46 _thread = thread;
47 _exception_detected = false;
48 _exception_caught = false;
49 _debuggable = true;
50 _hide_single_stepping = false;
51 _hide_level = 0;
52 _pending_step_for_popframe = false;
53 _class_being_redefined = NULL;
54 _class_load_kind = jvmti_class_load_kind_load;
55 _head_env_thread_state = NULL;
56 _dynamic_code_event_collector = NULL;
57 _vm_object_alloc_event_collector = NULL;
58 _the_class_for_redefinition_verification = NULL;
59 _scratch_class_for_redefinition_verification = NULL;
60
61 // JVMTI ForceEarlyReturn support
62 _pending_step_for_earlyret = false;
63 _earlyret_state = earlyret_inactive;
64 _earlyret_tos = ilgl;
65 _earlyret_value.j = 0L;
66 _earlyret_oop = NULL;
67
68 // add all the JvmtiEnvThreadState to the new JvmtiThreadState
69 {
70 JvmtiEnvIterator it;
71 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
72 if (env->is_valid()) {
73 add_env(env);
74 }
75 }
76 }
77
78 // link us into the list
79 {
80 // The thread state list manipulation code must not have safepoints.
81 // See periodic_clean_up().
82 debug_only(No_Safepoint_Verifier nosafepoint;)
83
84 _prev = NULL;
85 _next = _head;
86 if (_head != NULL) {
87 _head->_prev = this;
88 }
89 _head = this;
90 }
91
92 // set this as the state for the thread
93 thread->set_jvmti_thread_state(this);
94 }
95
96
97 JvmtiThreadState::~JvmtiThreadState() {
98 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
99
100 // clear this as the state for the thread
101 get_thread()->set_jvmti_thread_state(NULL);
102
103 // zap our env thread states
104 {
105 JvmtiEnvBase::entering_dying_thread_env_iteration();
106 JvmtiEnvThreadStateIterator it(this);
107 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ) {
108 JvmtiEnvThreadState* zap = ets;
109 ets = it.next(ets);
110 delete zap;
111 }
112 JvmtiEnvBase::leaving_dying_thread_env_iteration();
113 }
114
115 // remove us from the list
116 {
117 // The thread state list manipulation code must not have safepoints.
118 // See periodic_clean_up().
119 debug_only(No_Safepoint_Verifier nosafepoint;)
120
121 if (_prev == NULL) {
122 assert(_head == this, "sanity check");
123 _head = _next;
124 } else {
125 assert(_head != this, "sanity check");
126 _prev->_next = _next;
127 }
128 if (_next != NULL) {
129 _next->_prev = _prev;
130 }
131 _next = NULL;
132 _prev = NULL;
133 }
134 }
135
136
137 void
138 JvmtiThreadState::periodic_clean_up() {
139 assert(SafepointSynchronize::is_at_safepoint(), "at safepoint");
140
141 // This iteration is initialized with "_head" instead of "JvmtiThreadState::first()"
142 // because the latter requires the JvmtiThreadState_lock.
143 // This iteration is safe at a safepoint as well, see the No_Safepoint_Verifier
144 // asserts at all list manipulation sites.
145 for (JvmtiThreadState *state = _head; state != NULL; state = state->next()) {
146 // For each environment thread state corresponding to an invalid environment
147 // unlink it from the list and deallocate it.
148 JvmtiEnvThreadStateIterator it(state);
149 JvmtiEnvThreadState* previous_ets = NULL;
150 JvmtiEnvThreadState* ets = it.first();
151 while (ets != NULL) {
152 if (ets->get_env()->is_valid()) {
153 previous_ets = ets;
154 ets = it.next(ets);
155 } else {
156 // This one isn't valid, remove it from the list and deallocate it
157 JvmtiEnvThreadState* defunct_ets = ets;
158 ets = ets->next();
159 if (previous_ets == NULL) {
160 assert(state->head_env_thread_state() == defunct_ets, "sanity check");
161 state->set_head_env_thread_state(ets);
162 } else {
163 previous_ets->set_next(ets);
164 }
165 delete defunct_ets;
166 }
167 }
168 }
169 }
170
171 void JvmtiThreadState::add_env(JvmtiEnvBase *env) {
172 assert(JvmtiThreadState_lock->is_locked(), "sanity check");
173
174 JvmtiEnvThreadState *new_ets = new JvmtiEnvThreadState(_thread, env);
175 // add this environment thread state to the end of the list (order is important)
176 {
177 // list deallocation (which occurs at a safepoint) cannot occur simultaneously
178 debug_only(No_Safepoint_Verifier nosafepoint;)
179
180 JvmtiEnvThreadStateIterator it(this);
181 JvmtiEnvThreadState* previous_ets = NULL;
182 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) {
183 previous_ets = ets;
184 }
185 if (previous_ets == NULL) {
186 set_head_env_thread_state(new_ets);
187 } else {
188 previous_ets->set_next(new_ets);
189 }
190 }
191 }
192
193
194
195
196 void JvmtiThreadState::enter_interp_only_mode() {
197 assert(_thread->get_interp_only_mode() == 0, "entering interp only when mode not zero");
198 _thread->increment_interp_only_mode();
199 }
200
201
202 void JvmtiThreadState::leave_interp_only_mode() {
203 assert(_thread->get_interp_only_mode() == 1, "leaving interp only when mode not one");
204 _thread->decrement_interp_only_mode();
205 }
206
207
208 // Helper routine used in several places
209 int JvmtiThreadState::count_frames() {
210 #ifdef ASSERT
211 uint32_t debug_bits = 0;
212 #endif
213 assert(SafepointSynchronize::is_at_safepoint() ||
214 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits),
215 "at safepoint or must be suspended");
216
217 if (!get_thread()->has_last_Java_frame()) return 0; // no Java frames
218
219 ResourceMark rm;
220 RegisterMap reg_map(get_thread());
221 javaVFrame *jvf = get_thread()->last_java_vframe(®_map);
222 int n = 0;
223 // tty->print_cr("CSD: counting frames on %s ...",
224 // JvmtiTrace::safe_get_thread_name(get_thread()));
225 while (jvf != NULL) {
226 methodOop method = jvf->method();
227 // tty->print_cr("CSD: frame - method %s.%s - loc %d",
228 // method->klass_name()->as_C_string(),
229 // method->name()->as_C_string(),
230 // jvf->bci() );
231 jvf = jvf->java_sender();
232 n++;
233 }
234 // tty->print_cr("CSD: frame count: %d", n);
235 return n;
236 }
237
238
239 void JvmtiThreadState::invalidate_cur_stack_depth() {
240 Thread *cur = Thread::current();
241 uint32_t debug_bits = 0;
242
243 // The caller can be the VMThread at a safepoint, the current thread
244 // or the target thread must be suspended.
245 guarantee((cur->is_VM_thread() && SafepointSynchronize::is_at_safepoint()) ||
246 (JavaThread *)cur == get_thread() ||
247 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits),
248 "sanity check");
249
250 _cur_stack_depth = UNKNOWN_STACK_DEPTH;
251 }
252
253 void JvmtiThreadState::incr_cur_stack_depth() {
254 guarantee(JavaThread::current() == get_thread(), "must be current thread");
255
256 if (!is_interp_only_mode()) {
257 _cur_stack_depth = UNKNOWN_STACK_DEPTH;
258 }
259 if (_cur_stack_depth != UNKNOWN_STACK_DEPTH) {
260 ++_cur_stack_depth;
261 }
262 }
263
264 void JvmtiThreadState::decr_cur_stack_depth() {
265 guarantee(JavaThread::current() == get_thread(), "must be current thread");
266
267 if (!is_interp_only_mode()) {
268 _cur_stack_depth = UNKNOWN_STACK_DEPTH;
269 }
270 if (_cur_stack_depth != UNKNOWN_STACK_DEPTH) {
271 --_cur_stack_depth;
272 assert(_cur_stack_depth >= 0, "incr/decr_cur_stack_depth mismatch");
273 }
274 }
275
276 int JvmtiThreadState::cur_stack_depth() {
277 uint32_t debug_bits = 0;
278 guarantee(JavaThread::current() == get_thread() ||
279 JvmtiEnv::is_thread_fully_suspended(get_thread(), false, &debug_bits),
280 "must be current thread or suspended");
281
282 if (!is_interp_only_mode() || _cur_stack_depth == UNKNOWN_STACK_DEPTH) {
283 _cur_stack_depth = count_frames();
284 } else {
285 // heavy weight assert
286 assert(_cur_stack_depth == count_frames(),
287 "cur_stack_depth out of sync");
288 }
289 return _cur_stack_depth;
290 }
291
292 bool JvmtiThreadState::may_be_walked() {
293 return (get_thread()->is_being_ext_suspended() || (JavaThread::current() == get_thread()));
294 }
295
296
297 void JvmtiThreadState::process_pending_step_for_popframe() {
298 // We are single stepping as the last part of the PopFrame() dance
299 // so we have some house keeping to do.
300
301 JavaThread *thr = get_thread();
302 if (thr->popframe_condition() != JavaThread::popframe_inactive) {
303 // If the popframe_condition field is not popframe_inactive, then
304 // we missed all of the popframe_field cleanup points:
305 //
306 // - unpack_frames() was not called (nothing to deopt)
307 // - remove_activation_preserving_args_entry() was not called
308 // (did not get suspended in a call_vm() family call and did
309 // not complete a call_vm() family call on the way here)
310 thr->clear_popframe_condition();
311 }
312
313 // clearing the flag indicates we are done with the PopFrame() dance
314 clr_pending_step_for_popframe();
315
316 // If step is pending for popframe then it may not be
317 // a repeat step. The new_bci and method_id is same as current_bci
318 // and current method_id after pop and step for recursive calls.
319 // Force the step by clearing the last location.
320 JvmtiEnvThreadStateIterator it(this);
321 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) {
322 ets->clear_current_location();
323 }
324 }
325
326
327 // Class: JvmtiThreadState
328 // Function: update_for_pop_top_frame
329 // Description:
330 // This function removes any frame pop notification request for
331 // the top frame and invalidates both the current stack depth and
332 // all cached frameIDs.
333 //
334 // Called by: PopFrame
335 //
336 void JvmtiThreadState::update_for_pop_top_frame() {
337 if (is_interp_only_mode()) {
338 // remove any frame pop notification request for the top frame
339 // in any environment
340 int popframe_number = cur_stack_depth();
341 {
342 JvmtiEnvThreadStateIterator it(this);
343 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) {
344 if (ets->is_frame_pop(popframe_number)) {
345 ets->clear_frame_pop(popframe_number);
346 }
347 }
348 }
349 // force stack depth to be recalculated
350 invalidate_cur_stack_depth();
351 } else {
352 assert(!is_enabled(JVMTI_EVENT_FRAME_POP), "Must have no framepops set");
353 }
354 }
355
356
357 void JvmtiThreadState::process_pending_step_for_earlyret() {
358 // We are single stepping as the last part of the ForceEarlyReturn
359 // dance so we have some house keeping to do.
360
361 if (is_earlyret_pending()) {
362 // If the earlyret_state field is not earlyret_inactive, then
363 // we missed all of the earlyret_field cleanup points:
364 //
365 // - remove_activation() was not called
366 // (did not get suspended in a call_vm() family call and did
367 // not complete a call_vm() family call on the way here)
368 //
369 // One legitimate way for us to miss all the cleanup points is
370 // if we got here right after handling a compiled return. If that
371 // is the case, then we consider our return from compiled code to
372 // complete the ForceEarlyReturn request and we clear the condition.
373 clr_earlyret_pending();
374 set_earlyret_oop(NULL);
375 clr_earlyret_value();
376 }
377
378 // clearing the flag indicates we are done with
379 // the ForceEarlyReturn() dance
380 clr_pending_step_for_earlyret();
381
382 // If step is pending for earlyret then it may not be a repeat step.
383 // The new_bci and method_id is same as current_bci and current
384 // method_id after earlyret and step for recursive calls.
385 // Force the step by clearing the last location.
386 JvmtiEnvThreadStateIterator it(this);
387 for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) {
388 ets->clear_current_location();
389 }
390 }
391
392 void JvmtiThreadState::oops_do(OopClosure* f) {
393 f->do_oop((oop*) &_earlyret_oop);
394 }