1 /* 2 * Copyright (c) 1999, 2013, 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_JVMTIIMPL_HPP 26 #define SHARE_VM_PRIMS_JVMTIIMPL_HPP 27 28 #include "classfile/systemDictionary.hpp" 29 #include "jvmtifiles/jvmti.h" 30 #include "oops/objArrayOop.hpp" 31 #include "prims/jvmtiEnvThreadState.hpp" 32 #include "prims/jvmtiEventController.hpp" 33 #include "prims/jvmtiTrace.hpp" 34 #include "prims/jvmtiUtil.hpp" 35 #include "runtime/stackValueCollection.hpp" 36 #include "runtime/vm_operations.hpp" 37 38 // 39 // Forward Declarations 40 // 41 42 class JvmtiBreakpoint; 43 class JvmtiBreakpoints; 44 45 46 /////////////////////////////////////////////////////////////// 47 // 48 // class GrowableCache, GrowableElement 49 // Used by : JvmtiBreakpointCache 50 // Used by JVMTI methods: none directly. 51 // 52 // GrowableCache is a permanent CHeap growable array of <GrowableElement *> 53 // 54 // In addition, the GrowableCache maintains a NULL terminated cache array of type address 55 // that's created from the element array using the function: 56 // address GrowableElement::getCacheValue(). 57 // 58 // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated 59 // block of memory. Additionally, every time the cache changes its position in memory, the 60 // void (*_listener_fun)(void *this_obj, address* cache) 61 // gets called with the cache's new address. This gives the user of the GrowableCache a callback 62 // to update its pointer to the address cache. 63 // 64 65 class GrowableElement : public CHeapObj<mtInternal> { 66 public: 67 virtual address getCacheValue() =0; 68 virtual bool equals(GrowableElement* e) =0; 69 virtual bool lessThan(GrowableElement *e)=0; 70 virtual GrowableElement *clone() =0; 71 virtual void oops_do(OopClosure* f) =0; 72 }; 73 74 class GrowableCache VALUE_OBJ_CLASS_SPEC { 75 76 private: 77 // Object pointer passed into cache & listener functions. 78 void *_this_obj; 79 80 // Array of elements in the collection 81 GrowableArray<GrowableElement *> *_elements; 82 83 // Parallel array of cached values 84 address *_cache; 85 86 // Listener for changes to the _cache field. 87 // Called whenever the _cache field has it's value changed 88 // (but NOT when cached elements are recomputed). 89 void (*_listener_fun)(void *, address*); 90 91 static bool equals(void *, GrowableElement *); 92 93 // recache all elements after size change, notify listener 94 void recache(); 95 96 public: 97 GrowableCache(); 98 ~GrowableCache(); 99 100 void initialize(void *this_obj, void listener_fun(void *, address*) ); 101 102 // number of elements in the collection 103 int length(); 104 // get the value of the index element in the collection 105 GrowableElement* at(int index); 106 // find the index of the element, -1 if it doesn't exist 107 int find(GrowableElement* e); 108 // append a copy of the element to the end of the collection, notify listener 109 void append(GrowableElement* e); 110 // insert a copy of the element using lessthan(), notify listener 111 void insert(GrowableElement* e); 112 // remove the element at index, notify listener 113 void remove (int index); 114 // clear out all elements and release all heap space, notify listener 115 void clear(); 116 // apply f to every element and update the cache 117 void oops_do(OopClosure* f); 118 // update the cache after a full gc 119 void gc_epilogue(); 120 }; 121 122 123 /////////////////////////////////////////////////////////////// 124 // 125 // class JvmtiBreakpointCache 126 // Used by : JvmtiBreakpoints 127 // Used by JVMTI methods: none directly. 128 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 129 // 130 131 class JvmtiBreakpointCache : public CHeapObj<mtInternal> { 132 133 private: 134 GrowableCache _cache; 135 136 public: 137 JvmtiBreakpointCache() {} 138 ~JvmtiBreakpointCache() {} 139 140 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 141 _cache.initialize(this_obj,listener_fun); 142 } 143 144 int length() { return _cache.length(); } 145 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } 146 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } 147 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } 148 void remove (int index) { _cache.remove(index); } 149 void clear() { _cache.clear(); } 150 void oops_do(OopClosure* f) { _cache.oops_do(f); } 151 void gc_epilogue() { _cache.gc_epilogue(); } 152 }; 153 154 155 /////////////////////////////////////////////////////////////// 156 // 157 // class JvmtiBreakpoint 158 // Used by : JvmtiBreakpoints 159 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 160 // Note: Extends GrowableElement for use in a GrowableCache 161 // 162 // A JvmtiBreakpoint describes a location (class, method, bci) to break at. 163 // 164 165 typedef void (Method::*method_action)(int _bci); 166 167 class JvmtiBreakpoint : public GrowableElement { 168 private: 169 Method* _method; 170 int _bci; 171 Bytecodes::Code _orig_bytecode; 172 oop _class_loader; 173 174 public: 175 JvmtiBreakpoint(); 176 JvmtiBreakpoint(Method* m_method, jlocation location); 177 bool equals(JvmtiBreakpoint& bp); 178 bool lessThan(JvmtiBreakpoint &bp); 179 void copy(JvmtiBreakpoint& bp); 180 bool is_valid(); 181 address getBcp(); 182 void each_method_version_do(method_action meth_act); 183 void set(); 184 void clear(); 185 void print(); 186 187 Method* method() { return _method; } 188 189 // GrowableElement implementation 190 address getCacheValue() { return getBcp(); } 191 bool lessThan(GrowableElement* e) { Unimplemented(); return false; } 192 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 193 void oops_do(OopClosure* f) { 194 // Mark the method loader as live 195 f->do_oop(&_class_loader); 196 } 197 GrowableElement *clone() { 198 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 199 bp->copy(*this); 200 return bp; 201 } 202 }; 203 204 205 /////////////////////////////////////////////////////////////// 206 // 207 // class JvmtiBreakpoints 208 // Used by : JvmtiCurrentBreakpoints 209 // Used by JVMTI methods: none directly 210 // Note: A Helper class 211 // 212 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 213 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 214 // 215 // Because _bps is only modified at safepoints, its possible to always use the 216 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 217 // 218 // It would be possible to make JvmtiBreakpoints a static class, but I've made it 219 // CHeap allocated to emphasize its similarity to JvmtiFramePops. 220 // 221 222 class JvmtiBreakpoints : public CHeapObj<mtInternal> { 223 private: 224 225 JvmtiBreakpointCache _bps; 226 227 // These should only be used by VM_ChangeBreakpoints 228 // to insure they only occur at safepoints. 229 // Todo: add checks for safepoint 230 friend class VM_ChangeBreakpoints; 231 void set_at_safepoint(JvmtiBreakpoint& bp); 232 void clear_at_safepoint(JvmtiBreakpoint& bp); 233 234 static void do_element(GrowableElement *e); 235 236 public: 237 JvmtiBreakpoints(void listener_fun(void *, address *)); 238 ~JvmtiBreakpoints(); 239 240 int length(); 241 void oops_do(OopClosure* f); 242 void print(); 243 244 int set(JvmtiBreakpoint& bp); 245 int clear(JvmtiBreakpoint& bp); 246 void clearall_in_class_at_safepoint(Klass* klass); 247 void gc_epilogue(); 248 }; 249 250 251 /////////////////////////////////////////////////////////////// 252 // 253 // class JvmtiCurrentBreakpoints 254 // 255 // A static wrapper class for the JvmtiBreakpoints that provides: 256 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 257 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 258 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize 259 // JvmtiFramePops). 260 // 3. An oops_do entry point for GC'ing the breakpoint array. 261 // 262 263 class JvmtiCurrentBreakpoints : public AllStatic { 264 265 private: 266 267 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 268 static JvmtiBreakpoints *_jvmti_breakpoints; 269 270 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 271 // Updated only at safepoints (with listener_fun) when the cache is moved. 272 // It exists only to make is_breakpoint fast. 273 static address *_breakpoint_list; 274 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 275 static inline address *get_breakpoint_list() { return _breakpoint_list; } 276 277 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 278 static void listener_fun(void *this_obj, address *cache); 279 280 public: 281 static void initialize(); 282 static void destroy(); 283 284 // lazily create _jvmti_breakpoints and _breakpoint_list 285 static JvmtiBreakpoints& get_jvmti_breakpoints(); 286 287 // quickly test whether the bcp matches a cached breakpoint in the list 288 static inline bool is_breakpoint(address bcp); 289 290 static void oops_do(OopClosure* f); 291 static void gc_epilogue(); 292 }; 293 294 // quickly test whether the bcp matches a cached breakpoint in the list 295 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) { 296 address *bps = get_breakpoint_list(); 297 if (bps == NULL) return false; 298 for ( ; (*bps) != NULL; bps++) { 299 if ((*bps) == bcp) return true; 300 } 301 return false; 302 } 303 304 305 /////////////////////////////////////////////////////////////// 306 // 307 // class VM_ChangeBreakpoints 308 // Used by : JvmtiBreakpoints 309 // Used by JVMTI methods: none directly. 310 // Note: A Helper class. 311 // 312 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 313 // 314 315 class VM_ChangeBreakpoints : public VM_Operation { 316 private: 317 JvmtiBreakpoints* _breakpoints; 318 int _operation; 319 JvmtiBreakpoint* _bp; 320 321 public: 322 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 }; 323 324 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) { 325 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 326 _breakpoints = ¤t_bps; 327 _bp = bp; 328 _operation = operation; 329 assert(bp != NULL, "bp != NULL"); 330 } 331 332 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 333 void doit(); 334 void oops_do(OopClosure* f); 335 }; 336 337 338 /////////////////////////////////////////////////////////////// 339 // The get/set local operations must only be done by the VM thread 340 // because the interpreter version needs to access oop maps, which can 341 // only safely be done by the VM thread 342 // 343 // I'm told that in 1.5 oop maps are now protected by a lock and 344 // we could get rid of the VM op 345 // However if the VM op is removed then the target thread must 346 // be suspended AND a lock will be needed to prevent concurrent 347 // setting of locals to the same java thread. This lock is needed 348 // to prevent compiledVFrames from trying to add deferred updates 349 // to the thread simultaneously. 350 // 351 class VM_GetOrSetLocal : public VM_Operation { 352 protected: 353 JavaThread* _thread; 354 JavaThread* _calling_thread; 355 jint _depth; 356 jint _index; 357 BasicType _type; 358 jvalue _value; 359 javaVFrame* _jvf; 360 bool _set; 361 362 // It is possible to get the receiver out of a non-static native wrapper 363 // frame. Use VM_GetReceiver to do this. 364 virtual bool getting_receiver() const { return false; } 365 366 jvmtiError _result; 367 368 vframe* get_vframe(); 369 javaVFrame* get_java_vframe(); 370 bool check_slot_type(javaVFrame* vf); 371 372 public: 373 // Constructor for non-object getter 374 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 375 376 // Constructor for object or non-object setter 377 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 378 379 // Constructor for object getter 380 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 381 int index); 382 383 VMOp_Type type() const { return VMOp_GetOrSetLocal; } 384 jvalue value() { return _value; } 385 jvmtiError result() { return _result; } 386 387 bool doit_prologue(); 388 void doit(); 389 bool allow_nested_vm_operations() const; 390 const char* name() const { return "get/set locals"; } 391 392 // Check that the klass is assignable to a type with the given signature. 393 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 394 }; 395 396 class VM_GetReceiver : public VM_GetOrSetLocal { 397 protected: 398 virtual bool getting_receiver() const { return true; } 399 400 public: 401 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); 402 const char* name() const { return "get receiver"; } 403 }; 404 405 406 /////////////////////////////////////////////////////////////// 407 // 408 // class JvmtiSuspendControl 409 // 410 // Convenience routines for suspending and resuming threads. 411 // 412 // All attempts by JVMTI to suspend and resume threads must go through the 413 // JvmtiSuspendControl interface. 414 // 415 // methods return true if successful 416 // 417 class JvmtiSuspendControl : public AllStatic { 418 public: 419 // suspend the thread, taking it to a safepoint 420 static bool suspend(JavaThread *java_thread); 421 // resume the thread 422 static bool resume(JavaThread *java_thread); 423 424 static void print(); 425 }; 426 427 428 /** 429 * When a thread (such as the compiler thread or VM thread) cannot post a 430 * JVMTI event itself because the event needs to be posted from a Java 431 * thread, then it can defer the event to the Service thread for posting. 432 * The information needed to post the event is encapsulated into this class 433 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 434 * thread will pick it up and post it. 435 * 436 * This is currently only used for posting compiled-method-load and unload 437 * events, which we don't want posted from the compiler thread. 438 */ 439 class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { 440 friend class JvmtiDeferredEventQueue; 441 private: 442 typedef enum { 443 TYPE_NONE, 444 TYPE_COMPILED_METHOD_LOAD, 445 TYPE_COMPILED_METHOD_UNLOAD, 446 TYPE_DYNAMIC_CODE_GENERATED 447 } Type; 448 449 Type _type; 450 union { 451 nmethod* compiled_method_load; 452 struct { 453 nmethod* nm; 454 jmethodID method_id; 455 const void* code_begin; 456 } compiled_method_unload; 457 struct { 458 const char* name; 459 const void* code_begin; 460 const void* code_end; 461 } dynamic_code_generated; 462 } _event_data; 463 464 JvmtiDeferredEvent(Type t) : _type(t) {} 465 466 public: 467 468 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 469 470 // Factory methods 471 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 472 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 473 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm, 474 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 475 static JvmtiDeferredEvent dynamic_code_generated_event( 476 const char* name, const void* begin, const void* end) 477 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 478 479 // Actually posts the event. 480 void post() NOT_JVMTI_RETURN; 481 }; 482 483 /** 484 * Events enqueued on this queue wake up the Service thread which dequeues 485 * and posts the events. The Service_lock is required to be held 486 * when operating on the queue (except for the "pending" events). 487 */ 488 class JvmtiDeferredEventQueue : AllStatic { 489 friend class JvmtiDeferredEvent; 490 private: 491 class QueueNode : public CHeapObj<mtInternal> { 492 private: 493 JvmtiDeferredEvent _event; 494 QueueNode* _next; 495 496 public: 497 QueueNode(const JvmtiDeferredEvent& event) 498 : _event(event), _next(NULL) {} 499 500 const JvmtiDeferredEvent& event() const { return _event; } 501 QueueNode* next() const { return _next; } 502 503 void set_next(QueueNode* next) { _next = next; } 504 }; 505 506 static QueueNode* _queue_head; // Hold Service_lock to access 507 static QueueNode* _queue_tail; // Hold Service_lock to access 508 static volatile QueueNode* _pending_list; // Uses CAS for read/update 509 510 // Transfers events from the _pending_list to the _queue. 511 static void process_pending_events() NOT_JVMTI_RETURN; 512 513 public: 514 // Must be holding Service_lock when calling these 515 static bool has_events() NOT_JVMTI_RETURN_(false); 516 static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN; 517 static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 518 519 // Used to enqueue events without using a lock, for times (such as during 520 // safepoint) when we can't or don't want to lock the Service_lock. 521 // 522 // Events will be held off to the side until there's a call to 523 // dequeue(), enqueue(), or process_pending_events() (all of which require 524 // the holding of the Service_lock), and will be enqueued at that time. 525 static void add_pending_event(const JvmtiDeferredEvent&) NOT_JVMTI_RETURN; 526 }; 527 528 // Utility macro that checks for NULL pointers: 529 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 530 531 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP