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); // 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