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