1 /* 2 * Copyright (c) 1999, 2020, 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/escapeBarrier.hpp" 36 #include "runtime/stackValueCollection.hpp" 37 #include "runtime/vmOperations.hpp" 38 #include "utilities/ostream.hpp" 39 40 // 41 // Forward Declarations 42 // 43 44 class JvmtiBreakpoint; 45 class JvmtiBreakpoints; 46 47 48 /////////////////////////////////////////////////////////////// 49 // 50 // class GrowableCache, GrowableElement 51 // Used by : JvmtiBreakpointCache 52 // Used by JVMTI methods: none directly. 53 // 54 // GrowableCache is a permanent CHeap growable array of <GrowableElement *> 55 // 56 // In addition, the GrowableCache maintains a NULL terminated cache array of type address 57 // that's created from the element array using the function: 58 // address GrowableElement::getCacheValue(). 59 // 60 // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated 61 // block of memory. Additionally, every time the cache changes its position in memory, the 62 // void (*_listener_fun)(void *this_obj, address* cache) 63 // gets called with the cache's new address. This gives the user of the GrowableCache a callback 64 // to update its pointer to the address cache. 65 // 66 67 class GrowableElement : public CHeapObj<mtInternal> { 68 public: ~GrowableElement()69 virtual ~GrowableElement() {} 70 virtual address getCacheValue() =0; 71 virtual bool equals(GrowableElement* e) =0; 72 virtual GrowableElement *clone() =0; 73 }; 74 75 class GrowableCache { 76 77 private: 78 // Object pointer passed into cache & listener functions. 79 void *_this_obj; 80 81 // Array of elements in the collection 82 GrowableArray<GrowableElement *> *_elements; 83 84 // Parallel array of cached values 85 address *_cache; 86 87 // Listener for changes to the _cache field. 88 // Called whenever the _cache field has it's value changed 89 // (but NOT when cached elements are recomputed). 90 void (*_listener_fun)(void *, address*); 91 92 static bool equals(void *, GrowableElement *); 93 94 // recache all elements after size change, notify listener 95 void recache(); 96 97 public: 98 GrowableCache(); 99 ~GrowableCache(); 100 101 void initialize(void *this_obj, void listener_fun(void *, address*) ); 102 103 // number of elements in the collection 104 int length(); 105 // get the value of the index element in the collection 106 GrowableElement* at(int index); 107 // find the index of the element, -1 if it doesn't exist 108 int find(GrowableElement* e); 109 // append a copy of the element to the end of the collection, notify listener 110 void append(GrowableElement* e); 111 // remove the element at index, notify listener 112 void remove (int index); 113 // clear out all elements and release all heap space, notify listener 114 void clear(); 115 }; 116 117 118 /////////////////////////////////////////////////////////////// 119 // 120 // class JvmtiBreakpointCache 121 // Used by : JvmtiBreakpoints 122 // Used by JVMTI methods: none directly. 123 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 124 // 125 126 class JvmtiBreakpointCache : public CHeapObj<mtInternal> { 127 128 private: 129 GrowableCache _cache; 130 131 public: JvmtiBreakpointCache()132 JvmtiBreakpointCache() {} ~JvmtiBreakpointCache()133 ~JvmtiBreakpointCache() {} 134 initialize(void * this_obj,void listener_fun (void *,address *))135 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 136 _cache.initialize(this_obj, listener_fun); 137 } 138 length()139 int length() { return _cache.length(); } at(int index)140 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } find(JvmtiBreakpoint & e)141 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } append(JvmtiBreakpoint & e)142 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } remove(int index)143 void remove (int index) { _cache.remove(index); } 144 }; 145 146 147 /////////////////////////////////////////////////////////////// 148 // 149 // class JvmtiBreakpoint 150 // Used by : JvmtiBreakpoints 151 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 152 // Note: Extends GrowableElement for use in a GrowableCache 153 // 154 // A JvmtiBreakpoint describes a location (class, method, bci) to break at. 155 // 156 157 typedef void (Method::*method_action)(int _bci); 158 159 class JvmtiBreakpoint : public GrowableElement { 160 private: 161 Method* _method; 162 int _bci; 163 OopHandle _class_holder; // keeps _method memory from being deallocated 164 165 public: JvmtiBreakpoint()166 JvmtiBreakpoint() : _method(NULL), _bci(0) {} 167 JvmtiBreakpoint(Method* m_method, jlocation location); 168 virtual ~JvmtiBreakpoint(); 169 bool equals(JvmtiBreakpoint& bp); 170 void copy(JvmtiBreakpoint& bp); 171 address getBcp() const; 172 void each_method_version_do(method_action meth_act); 173 void set(); 174 void clear(); 175 void print_on(outputStream* out) const; 176 method()177 Method* method() { return _method; } 178 179 // GrowableElement implementation getCacheValue()180 address getCacheValue() { return getBcp(); } equals(GrowableElement * e)181 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 182 clone()183 GrowableElement *clone() { 184 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 185 bp->copy(*this); 186 return bp; 187 } 188 }; 189 190 191 /////////////////////////////////////////////////////////////// 192 // 193 // class JvmtiBreakpoints 194 // Used by : JvmtiCurrentBreakpoints 195 // Used by JVMTI methods: none directly 196 // Note: A Helper class 197 // 198 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 199 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 200 // 201 // Because _bps is only modified at safepoints, its possible to always use the 202 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 203 // 204 // It would be possible to make JvmtiBreakpoints a static class, but I've made it 205 // CHeap allocated to emphasize its similarity to JvmtiFramePops. 206 // 207 208 class JvmtiBreakpoints : public CHeapObj<mtInternal> { 209 private: 210 211 JvmtiBreakpointCache _bps; 212 213 // These should only be used by VM_ChangeBreakpoints 214 // to insure they only occur at safepoints. 215 // Todo: add checks for safepoint 216 friend class VM_ChangeBreakpoints; 217 void set_at_safepoint(JvmtiBreakpoint& bp); 218 void clear_at_safepoint(JvmtiBreakpoint& bp); 219 220 public: 221 JvmtiBreakpoints(void listener_fun(void *, address *)); 222 ~JvmtiBreakpoints(); 223 224 int length(); 225 void print(); 226 227 int set(JvmtiBreakpoint& bp); 228 int clear(JvmtiBreakpoint& bp); 229 void clearall_in_class_at_safepoint(Klass* klass); 230 }; 231 232 233 /////////////////////////////////////////////////////////////// 234 // 235 // class JvmtiCurrentBreakpoints 236 // 237 // A static wrapper class for the JvmtiBreakpoints that provides: 238 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 239 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 240 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize 241 // JvmtiFramePops). 242 // 3. An oops_do entry point for GC'ing the breakpoint array. 243 // 244 245 class JvmtiCurrentBreakpoints : public AllStatic { 246 247 private: 248 249 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 250 static JvmtiBreakpoints *_jvmti_breakpoints; 251 252 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 253 // Updated only at safepoints (with listener_fun) when the cache is moved. 254 // It exists only to make is_breakpoint fast. 255 static address *_breakpoint_list; set_breakpoint_list(address * breakpoint_list)256 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 257 258 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 259 static void listener_fun(void *this_obj, address *cache); 260 261 public: 262 static void initialize(); 263 static void destroy(); 264 265 // lazily create _jvmti_breakpoints and _breakpoint_list 266 static JvmtiBreakpoints& get_jvmti_breakpoints(); 267 }; 268 269 /////////////////////////////////////////////////////////////// 270 // 271 // class VM_ChangeBreakpoints 272 // Used by : JvmtiBreakpoints 273 // Used by JVMTI methods: none directly. 274 // Note: A Helper class. 275 // 276 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 277 // 278 279 class VM_ChangeBreakpoints : public VM_Operation { 280 private: 281 JvmtiBreakpoints* _breakpoints; 282 int _operation; 283 JvmtiBreakpoint* _bp; 284 285 public: 286 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 }; 287 VM_ChangeBreakpoints(int operation,JvmtiBreakpoint * bp)288 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) { 289 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 290 _breakpoints = ¤t_bps; 291 _bp = bp; 292 _operation = operation; 293 assert(bp != NULL, "bp != NULL"); 294 } 295 type() const296 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 297 void doit(); 298 }; 299 300 301 /////////////////////////////////////////////////////////////// 302 // The get/set local operations must only be done by the VM thread 303 // because the interpreter version needs to access oop maps, which can 304 // only safely be done by the VM thread 305 // 306 // I'm told that in 1.5 oop maps are now protected by a lock and 307 // we could get rid of the VM op 308 // However if the VM op is removed then the target thread must 309 // be suspended AND a lock will be needed to prevent concurrent 310 // setting of locals to the same java thread. This lock is needed 311 // to prevent compiledVFrames from trying to add deferred updates 312 // to the thread simultaneously. 313 // 314 class VM_GetOrSetLocal : public VM_Operation { 315 protected: 316 JavaThread* _thread; 317 JavaThread* _calling_thread; 318 jint _depth; 319 jint _index; 320 BasicType _type; 321 jvalue _value; 322 javaVFrame* _jvf; 323 bool _set; 324 325 EscapeBarrier _eb; 326 327 // It is possible to get the receiver out of a non-static native wrapper 328 // frame. Use VM_GetReceiver to do this. getting_receiver() const329 virtual bool getting_receiver() const { return false; } 330 331 jvmtiError _result; 332 333 vframe* get_vframe(); 334 javaVFrame* get_java_vframe(); 335 bool check_slot_type_lvt(javaVFrame* vf); 336 bool check_slot_type_no_lvt(javaVFrame* vf); 337 338 public: 339 // Constructor for non-object getter 340 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 341 342 // Constructor for object or non-object setter 343 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 344 345 // Constructor for object getter 346 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 347 int index); 348 type() const349 VMOp_Type type() const { return VMOp_GetOrSetLocal; } value()350 jvalue value() { return _value; } result()351 jvmtiError result() { return _result; } 352 353 bool doit_prologue(); 354 void doit(); 355 bool allow_nested_vm_operations() const; name() const356 const char* name() const { return "get/set locals"; } 357 358 // Check that the klass is assignable to a type with the given signature. 359 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 360 }; 361 362 class VM_GetReceiver : public VM_GetOrSetLocal { 363 protected: getting_receiver() const364 virtual bool getting_receiver() const { return true; } 365 366 public: 367 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); name() const368 const char* name() const { return "get receiver"; } 369 }; 370 371 372 /////////////////////////////////////////////////////////////// 373 // 374 // class JvmtiSuspendControl 375 // 376 // Convenience routines for suspending and resuming threads. 377 // 378 // All attempts by JVMTI to suspend and resume threads must go through the 379 // JvmtiSuspendControl interface. 380 // 381 // methods return true if successful 382 // 383 class JvmtiSuspendControl : public AllStatic { 384 public: 385 // suspend the thread, taking it to a safepoint 386 static bool suspend(JavaThread *java_thread); 387 // resume the thread 388 static bool resume(JavaThread *java_thread); 389 390 static void print(); 391 }; 392 393 394 /** 395 * When a thread (such as the compiler thread or VM thread) cannot post a 396 * JVMTI event itself because the event needs to be posted from a Java 397 * thread, then it can defer the event to the Service thread for posting. 398 * The information needed to post the event is encapsulated into this class 399 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 400 * thread will pick it up and post it. 401 * 402 * This is currently only used for posting compiled-method-load and unload 403 * events, which we don't want posted from the compiler thread. 404 */ 405 class JvmtiDeferredEvent { 406 friend class JvmtiDeferredEventQueue; 407 private: 408 typedef enum { 409 TYPE_NONE, 410 TYPE_COMPILED_METHOD_LOAD, 411 TYPE_COMPILED_METHOD_UNLOAD, 412 TYPE_DYNAMIC_CODE_GENERATED, 413 TYPE_CLASS_UNLOAD 414 } Type; 415 416 Type _type; 417 union { 418 nmethod* compiled_method_load; 419 struct { 420 jmethodID method_id; 421 const void* code_begin; 422 } compiled_method_unload; 423 struct { 424 const char* name; 425 const void* code_begin; 426 const void* code_end; 427 } dynamic_code_generated; 428 struct { 429 const char* name; 430 } class_unload; 431 } _event_data; 432 JvmtiDeferredEvent(Type t)433 JvmtiDeferredEvent(Type t) : _type(t) {} 434 435 public: 436 JvmtiDeferredEvent()437 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 438 439 // Factory methods 440 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 441 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 442 static JvmtiDeferredEvent compiled_method_unload_event( 443 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 444 static JvmtiDeferredEvent dynamic_code_generated_event( 445 const char* name, const void* begin, const void* end) 446 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 447 static JvmtiDeferredEvent class_unload_event( 448 const char* name) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 449 450 // Actually posts the event. 451 void post() NOT_JVMTI_RETURN; 452 void post_compiled_method_load_event(JvmtiEnv* env) NOT_JVMTI_RETURN; 453 void run_nmethod_entry_barriers() NOT_JVMTI_RETURN; 454 // Sweeper support to keep nmethods from being zombied while in the queue. 455 void nmethods_do(CodeBlobClosure* cf) NOT_JVMTI_RETURN; 456 // GC support to keep nmethod from being unloaded while in the queue. 457 void oops_do(OopClosure* f, CodeBlobClosure* cf) NOT_JVMTI_RETURN; 458 }; 459 460 /** 461 * Events enqueued on this queue wake up the Service thread which dequeues 462 * and posts the events. The Service_lock is required to be held 463 * when operating on the queue. 464 */ 465 class JvmtiDeferredEventQueue : public CHeapObj<mtInternal> { 466 friend class JvmtiDeferredEvent; 467 private: 468 class QueueNode : public CHeapObj<mtInternal> { 469 private: 470 JvmtiDeferredEvent _event; 471 QueueNode* _next; 472 473 public: QueueNode(const JvmtiDeferredEvent & event)474 QueueNode(const JvmtiDeferredEvent& event) 475 : _event(event), _next(NULL) {} 476 event()477 JvmtiDeferredEvent& event() { return _event; } next() const478 QueueNode* next() const { return _next; } 479 set_next(QueueNode * next)480 void set_next(QueueNode* next) { _next = next; } 481 }; 482 483 QueueNode* _queue_head; 484 QueueNode* _queue_tail; 485 486 public: JvmtiDeferredEventQueue()487 JvmtiDeferredEventQueue() : _queue_head(NULL), _queue_tail(NULL) {} 488 489 bool has_events() NOT_JVMTI_RETURN_(false); 490 JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 491 492 // Post all events in the queue for the current Jvmti environment 493 void post(JvmtiEnv* env) NOT_JVMTI_RETURN; 494 void enqueue(JvmtiDeferredEvent event) NOT_JVMTI_RETURN; 495 void run_nmethod_entry_barriers(); 496 497 // Sweeper support to keep nmethods from being zombied while in the queue. 498 void nmethods_do(CodeBlobClosure* cf) NOT_JVMTI_RETURN; 499 // GC support to keep nmethod from being unloaded while in the queue. 500 void oops_do(OopClosure* f, CodeBlobClosure* cf) NOT_JVMTI_RETURN; 501 }; 502 503 // Utility macro that checks for NULL pointers: 504 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 505 506 #endif // SHARE_PRIMS_JVMTIIMPL_HPP 507