1 /* 2 * Copyright (c) 1999, 2019, 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_PRIMS_JVMTIIMPL_HPP 26 #define SHARE_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/vmOperations.hpp" 37 #include "utilities/ostream.hpp" 38 39 // 40 // Forward Declarations 41 // 42 43 class JvmtiBreakpoint; 44 class JvmtiBreakpoints; 45 46 47 /////////////////////////////////////////////////////////////// 48 // 49 // class GrowableCache, GrowableElement 50 // Used by : JvmtiBreakpointCache 51 // Used by JVMTI methods: none directly. 52 // 53 // GrowableCache is a permanent CHeap growable array of <GrowableElement *> 54 // 55 // In addition, the GrowableCache maintains a NULL terminated cache array of type address 56 // that's created from the element array using the function: 57 // address GrowableElement::getCacheValue(). 58 // 59 // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated 60 // block of memory. Additionally, every time the cache changes its position in memory, the 61 // void (*_listener_fun)(void *this_obj, address* cache) 62 // gets called with the cache's new address. This gives the user of the GrowableCache a callback 63 // to update its pointer to the address cache. 64 // 65 66 class GrowableElement : public CHeapObj<mtInternal> { 67 public: ~GrowableElement()68 virtual ~GrowableElement() {} 69 virtual address getCacheValue() =0; 70 virtual bool equals(GrowableElement* e) =0; 71 virtual GrowableElement *clone() =0; 72 }; 73 74 class GrowableCache { 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 // remove the element at index, notify listener 111 void remove (int index); 112 // clear out all elements and release all heap space, notify listener 113 void clear(); 114 }; 115 116 117 /////////////////////////////////////////////////////////////// 118 // 119 // class JvmtiBreakpointCache 120 // Used by : JvmtiBreakpoints 121 // Used by JVMTI methods: none directly. 122 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 123 // 124 125 class JvmtiBreakpointCache : public CHeapObj<mtInternal> { 126 127 private: 128 GrowableCache _cache; 129 130 public: JvmtiBreakpointCache()131 JvmtiBreakpointCache() {} ~JvmtiBreakpointCache()132 ~JvmtiBreakpointCache() {} 133 initialize(void * this_obj,void listener_fun (void *,address *))134 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 135 _cache.initialize(this_obj, listener_fun); 136 } 137 length()138 int length() { return _cache.length(); } at(int index)139 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } find(JvmtiBreakpoint & e)140 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } append(JvmtiBreakpoint & e)141 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } remove(int index)142 void remove (int index) { _cache.remove(index); } 143 }; 144 145 146 /////////////////////////////////////////////////////////////// 147 // 148 // class JvmtiBreakpoint 149 // Used by : JvmtiBreakpoints 150 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 151 // Note: Extends GrowableElement for use in a GrowableCache 152 // 153 // A JvmtiBreakpoint describes a location (class, method, bci) to break at. 154 // 155 156 typedef void (Method::*method_action)(int _bci); 157 158 class JvmtiBreakpoint : public GrowableElement { 159 private: 160 Method* _method; 161 int _bci; 162 oop* _class_holder; // keeps _method memory from being deallocated 163 164 public: JvmtiBreakpoint()165 JvmtiBreakpoint() : _method(NULL), _bci(0), _class_holder(NULL) {} 166 JvmtiBreakpoint(Method* m_method, jlocation location); 167 virtual ~JvmtiBreakpoint(); 168 bool equals(JvmtiBreakpoint& bp); 169 void copy(JvmtiBreakpoint& bp); 170 address getBcp() const; 171 void each_method_version_do(method_action meth_act); 172 void set(); 173 void clear(); 174 void print_on(outputStream* out) const; 175 method()176 Method* method() { return _method; } 177 178 // GrowableElement implementation getCacheValue()179 address getCacheValue() { return getBcp(); } equals(GrowableElement * e)180 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 181 clone()182 GrowableElement *clone() { 183 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 184 bp->copy(*this); 185 return bp; 186 } 187 }; 188 189 190 /////////////////////////////////////////////////////////////// 191 // 192 // class JvmtiBreakpoints 193 // Used by : JvmtiCurrentBreakpoints 194 // Used by JVMTI methods: none directly 195 // Note: A Helper class 196 // 197 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 198 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 199 // 200 // Because _bps is only modified at safepoints, its possible to always use the 201 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 202 // 203 // It would be possible to make JvmtiBreakpoints a static class, but I've made it 204 // CHeap allocated to emphasize its similarity to JvmtiFramePops. 205 // 206 207 class JvmtiBreakpoints : public CHeapObj<mtInternal> { 208 private: 209 210 JvmtiBreakpointCache _bps; 211 212 // These should only be used by VM_ChangeBreakpoints 213 // to insure they only occur at safepoints. 214 // Todo: add checks for safepoint 215 friend class VM_ChangeBreakpoints; 216 void set_at_safepoint(JvmtiBreakpoint& bp); 217 void clear_at_safepoint(JvmtiBreakpoint& bp); 218 219 public: 220 JvmtiBreakpoints(void listener_fun(void *, address *)); 221 ~JvmtiBreakpoints(); 222 223 int length(); 224 void print(); 225 226 int set(JvmtiBreakpoint& bp); 227 int clear(JvmtiBreakpoint& bp); 228 void clearall_in_class_at_safepoint(Klass* klass); 229 }; 230 231 232 /////////////////////////////////////////////////////////////// 233 // 234 // class JvmtiCurrentBreakpoints 235 // 236 // A static wrapper class for the JvmtiBreakpoints that provides: 237 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 238 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 239 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize 240 // JvmtiFramePops). 241 // 3. An oops_do entry point for GC'ing the breakpoint array. 242 // 243 244 class JvmtiCurrentBreakpoints : public AllStatic { 245 246 private: 247 248 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 249 static JvmtiBreakpoints *_jvmti_breakpoints; 250 251 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 252 // Updated only at safepoints (with listener_fun) when the cache is moved. 253 // It exists only to make is_breakpoint fast. 254 static address *_breakpoint_list; set_breakpoint_list(address * breakpoint_list)255 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 256 257 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 258 static void listener_fun(void *this_obj, address *cache); 259 260 public: 261 static void initialize(); 262 static void destroy(); 263 264 // lazily create _jvmti_breakpoints and _breakpoint_list 265 static JvmtiBreakpoints& get_jvmti_breakpoints(); 266 }; 267 268 /////////////////////////////////////////////////////////////// 269 // 270 // class VM_ChangeBreakpoints 271 // Used by : JvmtiBreakpoints 272 // Used by JVMTI methods: none directly. 273 // Note: A Helper class. 274 // 275 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 276 // 277 278 class VM_ChangeBreakpoints : public VM_Operation { 279 private: 280 JvmtiBreakpoints* _breakpoints; 281 int _operation; 282 JvmtiBreakpoint* _bp; 283 284 public: 285 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 }; 286 VM_ChangeBreakpoints(int operation,JvmtiBreakpoint * bp)287 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) { 288 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 289 _breakpoints = ¤t_bps; 290 _bp = bp; 291 _operation = operation; 292 assert(bp != NULL, "bp != NULL"); 293 } 294 type() const295 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 296 void doit(); 297 }; 298 299 300 /////////////////////////////////////////////////////////////// 301 // The get/set local operations must only be done by the VM thread 302 // because the interpreter version needs to access oop maps, which can 303 // only safely be done by the VM thread 304 // 305 // I'm told that in 1.5 oop maps are now protected by a lock and 306 // we could get rid of the VM op 307 // However if the VM op is removed then the target thread must 308 // be suspended AND a lock will be needed to prevent concurrent 309 // setting of locals to the same java thread. This lock is needed 310 // to prevent compiledVFrames from trying to add deferred updates 311 // to the thread simultaneously. 312 // 313 class VM_GetOrSetLocal : public VM_Operation { 314 protected: 315 JavaThread* _thread; 316 JavaThread* _calling_thread; 317 jint _depth; 318 jint _index; 319 BasicType _type; 320 jvalue _value; 321 javaVFrame* _jvf; 322 bool _set; 323 324 // It is possible to get the receiver out of a non-static native wrapper 325 // frame. Use VM_GetReceiver to do this. getting_receiver() const326 virtual bool getting_receiver() const { return false; } 327 328 jvmtiError _result; 329 330 vframe* get_vframe(); 331 javaVFrame* get_java_vframe(); 332 bool check_slot_type_lvt(javaVFrame* vf); 333 bool check_slot_type_no_lvt(javaVFrame* vf); 334 335 public: 336 // Constructor for non-object getter 337 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 338 339 // Constructor for object or non-object setter 340 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 341 342 // Constructor for object getter 343 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 344 int index); 345 type() const346 VMOp_Type type() const { return VMOp_GetOrSetLocal; } value()347 jvalue value() { return _value; } result()348 jvmtiError result() { return _result; } 349 350 bool doit_prologue(); 351 void doit(); 352 bool allow_nested_vm_operations() const; name() const353 const char* name() const { return "get/set locals"; } 354 355 // Check that the klass is assignable to a type with the given signature. 356 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 357 }; 358 359 class VM_GetReceiver : public VM_GetOrSetLocal { 360 protected: getting_receiver() const361 virtual bool getting_receiver() const { return true; } 362 363 public: 364 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); name() const365 const char* name() const { return "get receiver"; } 366 }; 367 368 369 /////////////////////////////////////////////////////////////// 370 // 371 // class JvmtiSuspendControl 372 // 373 // Convenience routines for suspending and resuming threads. 374 // 375 // All attempts by JVMTI to suspend and resume threads must go through the 376 // JvmtiSuspendControl interface. 377 // 378 // methods return true if successful 379 // 380 class JvmtiSuspendControl : public AllStatic { 381 public: 382 // suspend the thread, taking it to a safepoint 383 static bool suspend(JavaThread *java_thread); 384 // resume the thread 385 static bool resume(JavaThread *java_thread); 386 387 static void print(); 388 }; 389 390 391 /** 392 * When a thread (such as the compiler thread or VM thread) cannot post a 393 * JVMTI event itself because the event needs to be posted from a Java 394 * thread, then it can defer the event to the Service thread for posting. 395 * The information needed to post the event is encapsulated into this class 396 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 397 * thread will pick it up and post it. 398 * 399 * This is currently only used for posting compiled-method-load and unload 400 * events, which we don't want posted from the compiler thread. 401 */ 402 class JvmtiDeferredEvent { 403 friend class JvmtiDeferredEventQueue; 404 private: 405 typedef enum { 406 TYPE_NONE, 407 TYPE_COMPILED_METHOD_LOAD, 408 TYPE_COMPILED_METHOD_UNLOAD, 409 TYPE_DYNAMIC_CODE_GENERATED, 410 TYPE_CLASS_UNLOAD 411 } Type; 412 413 Type _type; 414 union { 415 nmethod* compiled_method_load; 416 struct { 417 jmethodID method_id; 418 const void* code_begin; 419 } compiled_method_unload; 420 struct { 421 const char* name; 422 const void* code_begin; 423 const void* code_end; 424 } dynamic_code_generated; 425 struct { 426 const char* name; 427 } class_unload; 428 } _event_data; 429 JvmtiDeferredEvent(Type t)430 JvmtiDeferredEvent(Type t) : _type(t) {} 431 432 public: 433 JvmtiDeferredEvent()434 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 435 436 // Factory methods 437 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 438 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 439 static JvmtiDeferredEvent compiled_method_unload_event( 440 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 441 static JvmtiDeferredEvent dynamic_code_generated_event( 442 const char* name, const void* begin, const void* end) 443 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 444 static JvmtiDeferredEvent class_unload_event( 445 const char* name) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 446 447 // Actually posts the event. 448 void post() NOT_JVMTI_RETURN; 449 void post_compiled_method_load_event(JvmtiEnv* env) NOT_JVMTI_RETURN; 450 void run_nmethod_entry_barriers() NOT_JVMTI_RETURN; 451 // Sweeper support to keep nmethods from being zombied while in the queue. 452 void nmethods_do(CodeBlobClosure* cf) NOT_JVMTI_RETURN; 453 // GC support to keep nmethod from being unloaded while in the queue. 454 void oops_do(OopClosure* f, CodeBlobClosure* cf) NOT_JVMTI_RETURN; 455 }; 456 457 /** 458 * Events enqueued on this queue wake up the Service thread which dequeues 459 * and posts the events. The Service_lock is required to be held 460 * when operating on the queue. 461 */ 462 class JvmtiDeferredEventQueue : public CHeapObj<mtInternal> { 463 friend class JvmtiDeferredEvent; 464 private: 465 class QueueNode : public CHeapObj<mtInternal> { 466 private: 467 JvmtiDeferredEvent _event; 468 QueueNode* _next; 469 470 public: QueueNode(const JvmtiDeferredEvent & event)471 QueueNode(const JvmtiDeferredEvent& event) 472 : _event(event), _next(NULL) {} 473 event()474 JvmtiDeferredEvent& event() { return _event; } next() const475 QueueNode* next() const { return _next; } 476 set_next(QueueNode * next)477 void set_next(QueueNode* next) { _next = next; } 478 }; 479 480 QueueNode* _queue_head; 481 QueueNode* _queue_tail; 482 483 public: JvmtiDeferredEventQueue()484 JvmtiDeferredEventQueue() : _queue_head(NULL), _queue_tail(NULL) {} 485 486 bool has_events() NOT_JVMTI_RETURN_(false); 487 JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 488 489 // Post all events in the queue for the current Jvmti environment 490 void post(JvmtiEnv* env) NOT_JVMTI_RETURN; 491 void enqueue(JvmtiDeferredEvent event) NOT_JVMTI_RETURN; 492 void run_nmethod_entry_barriers(); 493 494 // Sweeper support to keep nmethods from being zombied while in the queue. 495 void nmethods_do(CodeBlobClosure* cf) NOT_JVMTI_RETURN; 496 // GC support to keep nmethod from being unloaded while in the queue. 497 void oops_do(OopClosure* f, CodeBlobClosure* cf) NOT_JVMTI_RETURN; 498 }; 499 500 // Utility macro that checks for NULL pointers: 501 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 502 503 #endif // SHARE_PRIMS_JVMTIIMPL_HPP 504