1 /* 2 * Copyright (c) 1999, 2011, 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 #ifndef JVMTI_KERNEL 29 30 #include "classfile/systemDictionary.hpp" 31 #include "jvmtifiles/jvmti.h" 32 #include "oops/objArrayOop.hpp" 33 #include "prims/jvmtiEnvThreadState.hpp" 34 #include "prims/jvmtiEventController.hpp" 35 #include "prims/jvmtiTrace.hpp" 36 #include "prims/jvmtiUtil.hpp" 37 #include "runtime/stackValueCollection.hpp" 38 #include "runtime/vm_operations.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 { 68 public: 69 virtual address getCacheValue() =0; 70 virtual bool equals(GrowableElement* e) =0; 71 virtual bool lessThan(GrowableElement *e)=0; 72 virtual GrowableElement *clone() =0; 73 virtual void oops_do(OopClosure* f) =0; 74 }; 75 76 class GrowableCache VALUE_OBJ_CLASS_SPEC { 77 78 private: 79 // Object pointer passed into cache & listener functions. 80 void *_this_obj; 81 82 // Array of elements in the collection 83 GrowableArray<GrowableElement *> *_elements; 84 85 // Parallel array of cached values 86 address *_cache; 87 88 // Listener for changes to the _cache field. 89 // Called whenever the _cache field has it's value changed 90 // (but NOT when cached elements are recomputed). 91 void (*_listener_fun)(void *, address*); 92 93 static bool equals(void *, GrowableElement *); 94 95 // recache all elements after size change, notify listener 96 void recache(); 97 98 public: 99 GrowableCache(); 100 ~GrowableCache(); 101 102 void initialize(void *this_obj, void listener_fun(void *, address*) ); 103 104 // number of elements in the collection 105 int length(); 106 // get the value of the index element in the collection 107 GrowableElement* at(int index); 108 // find the index of the element, -1 if it doesn't exist 109 int find(GrowableElement* e); 110 // append a copy of the element to the end of the collection, notify listener 111 void append(GrowableElement* e); 112 // insert a copy of the element using lessthan(), notify listener 113 void insert(GrowableElement* e); 114 // remove the element at index, notify listener 115 void remove (int index); 116 // clear out all elements and release all heap space, notify listener 117 void clear(); 118 // apply f to every element and update the cache 119 void oops_do(OopClosure* f); 120 // update the cache after a full gc 121 void gc_epilogue(); 122 }; 123 124 125 /////////////////////////////////////////////////////////////// 126 // 127 // class JvmtiBreakpointCache 128 // Used by : JvmtiBreakpoints 129 // Used by JVMTI methods: none directly. 130 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 131 // 132 133 class JvmtiBreakpointCache : public CHeapObj { 134 135 private: 136 GrowableCache _cache; 137 138 public: 139 JvmtiBreakpointCache() {} 140 ~JvmtiBreakpointCache() {} 141 142 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 143 _cache.initialize(this_obj,listener_fun); 144 } 145 146 int length() { return _cache.length(); } 147 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } 148 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } 149 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } 150 void remove (int index) { _cache.remove(index); } 151 void clear() { _cache.clear(); } 152 void oops_do(OopClosure* f) { _cache.oops_do(f); } 153 void gc_epilogue() { _cache.gc_epilogue(); } 154 }; 155 156 157 /////////////////////////////////////////////////////////////// 158 // 159 // class JvmtiBreakpoint 160 // Used by : JvmtiBreakpoints 161 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 162 // Note: Extends GrowableElement for use in a GrowableCache 163 // 164 // A JvmtiBreakpoint describes a location (class, method, bci) to break at. 165 // 166 167 typedef void (methodOopDesc::*method_action)(int _bci); 168 169 class JvmtiBreakpoint : public GrowableElement { 170 private: 171 methodOop _method; 172 int _bci; 173 Bytecodes::Code _orig_bytecode; 174 175 public: 176 JvmtiBreakpoint(); 177 JvmtiBreakpoint(methodOop m_method, jlocation location); 178 bool equals(JvmtiBreakpoint& bp); 179 bool lessThan(JvmtiBreakpoint &bp); 180 void copy(JvmtiBreakpoint& bp); 181 bool is_valid(); 182 address getBcp(); 183 void each_method_version_do(method_action meth_act); 184 void set(); 185 void clear(); 186 void print(); 187 188 methodOop method() { return _method; } 189 190 // GrowableElement implementation 191 address getCacheValue() { return getBcp(); } 192 bool lessThan(GrowableElement* e) { Unimplemented(); return false; } 193 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 194 void oops_do(OopClosure* f) { f->do_oop((oop *) &_method); } 195 GrowableElement *clone() { 196 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 197 bp->copy(*this); 198 return bp; 199 } 200 }; 201 202 203 /////////////////////////////////////////////////////////////// 204 // 205 // class VM_ChangeBreakpoints 206 // Used by : JvmtiBreakpoints 207 // Used by JVMTI methods: none directly. 208 // Note: A Helper class. 209 // 210 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 211 // 212 213 class VM_ChangeBreakpoints : public VM_Operation { 214 private: 215 JvmtiBreakpoints* _breakpoints; 216 int _operation; 217 JvmtiBreakpoint* _bp; 218 219 public: 220 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1, CLEAR_ALL_BREAKPOINT=2 }; 221 222 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation) { 223 _breakpoints = breakpoints; 224 _bp = NULL; 225 _operation = operation; 226 assert(breakpoints != NULL, "breakpoints != NULL"); 227 assert(operation == CLEAR_ALL_BREAKPOINT, "unknown breakpoint operation"); 228 } 229 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation, JvmtiBreakpoint *bp) { 230 _breakpoints = breakpoints; 231 _bp = bp; 232 _operation = operation; 233 assert(breakpoints != NULL, "breakpoints != NULL"); 234 assert(bp != NULL, "bp != NULL"); 235 assert(operation == SET_BREAKPOINT || operation == CLEAR_BREAKPOINT , "unknown breakpoint operation"); 236 } 237 238 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 239 void doit(); 240 void oops_do(OopClosure* f); 241 }; 242 243 244 /////////////////////////////////////////////////////////////// 245 // 246 // class JvmtiBreakpoints 247 // Used by : JvmtiCurrentBreakpoints 248 // Used by JVMTI methods: none directly 249 // Note: A Helper class 250 // 251 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 252 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 253 // 254 // Because _bps is only modified at safepoints, its possible to always use the 255 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 256 // 257 // It would be possible to make JvmtiBreakpoints a static class, but I've made it 258 // CHeap allocated to emphasize its similarity to JvmtiFramePops. 259 // 260 261 class JvmtiBreakpoints : public CHeapObj { 262 private: 263 264 JvmtiBreakpointCache _bps; 265 266 // These should only be used by VM_ChangeBreakpoints 267 // to insure they only occur at safepoints. 268 // Todo: add checks for safepoint 269 friend class VM_ChangeBreakpoints; 270 void set_at_safepoint(JvmtiBreakpoint& bp); 271 void clear_at_safepoint(JvmtiBreakpoint& bp); 272 void clearall_at_safepoint(); 273 274 static void do_element(GrowableElement *e); 275 276 public: 277 JvmtiBreakpoints(void listener_fun(void *, address *)); 278 ~JvmtiBreakpoints(); 279 280 int length(); 281 void oops_do(OopClosure* f); 282 void print(); 283 284 int set(JvmtiBreakpoint& bp); 285 int clear(JvmtiBreakpoint& bp); 286 void clearall_in_class_at_safepoint(klassOop klass); 287 void clearall(); 288 void gc_epilogue(); 289 }; 290 291 292 /////////////////////////////////////////////////////////////// 293 // 294 // class JvmtiCurrentBreakpoints 295 // 296 // A static wrapper class for the JvmtiBreakpoints that provides: 297 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 298 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 299 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize 300 // JvmtiFramePops). 301 // 3. An oops_do entry point for GC'ing the breakpoint array. 302 // 303 304 class JvmtiCurrentBreakpoints : public AllStatic { 305 306 private: 307 308 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 309 static JvmtiBreakpoints *_jvmti_breakpoints; 310 311 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 312 // Updated only at safepoints (with listener_fun) when the cache is moved. 313 // It exists only to make is_breakpoint fast. 314 static address *_breakpoint_list; 315 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 316 static inline address *get_breakpoint_list() { return _breakpoint_list; } 317 318 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 319 static void listener_fun(void *this_obj, address *cache); 320 321 public: 322 static void initialize(); 323 static void destroy(); 324 325 // lazily create _jvmti_breakpoints and _breakpoint_list 326 static JvmtiBreakpoints& get_jvmti_breakpoints(); 327 328 // quickly test whether the bcp matches a cached breakpoint in the list 329 static inline bool is_breakpoint(address bcp); 330 331 static void oops_do(OopClosure* f); 332 static void gc_epilogue(); 333 }; 334 335 // quickly test whether the bcp matches a cached breakpoint in the list 336 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) { 337 address *bps = get_breakpoint_list(); 338 if (bps == NULL) return false; 339 for ( ; (*bps) != NULL; bps++) { 340 if ((*bps) == bcp) return true; 341 } 342 return false; 343 } 344 345 /////////////////////////////////////////////////////////////// 346 // The get/set local operations must only be done by the VM thread 347 // because the interpreter version needs to access oop maps, which can 348 // only safely be done by the VM thread 349 // 350 // I'm told that in 1.5 oop maps are now protected by a lock and 351 // we could get rid of the VM op 352 // However if the VM op is removed then the target thread must 353 // be suspended AND a lock will be needed to prevent concurrent 354 // setting of locals to the same java thread. This lock is needed 355 // to prevent compiledVFrames from trying to add deferred updates 356 // to the thread simultaneously. 357 // 358 class VM_GetOrSetLocal : public VM_Operation { 359 protected: 360 JavaThread* _thread; 361 JavaThread* _calling_thread; 362 jint _depth; 363 jint _index; 364 BasicType _type; 365 jvalue _value; 366 javaVFrame* _jvf; 367 bool _set; 368 369 // It is possible to get the receiver out of a non-static native wrapper 370 // frame. Use VM_GetReceiver to do this. 371 virtual bool getting_receiver() const { return false; } 372 373 jvmtiError _result; 374 375 vframe* get_vframe(); 376 javaVFrame* get_java_vframe(); 377 bool check_slot_type(javaVFrame* vf); 378 379 public: 380 // Constructor for non-object getter 381 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 382 383 // Constructor for object or non-object setter 384 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 385 386 // Constructor for object getter 387 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 388 int index); 389 390 VMOp_Type type() const { return VMOp_GetOrSetLocal; } 391 jvalue value() { return _value; } 392 jvmtiError result() { return _result; } 393 394 bool doit_prologue(); 395 void doit(); 396 bool allow_nested_vm_operations() const; 397 const char* name() const { return "get/set locals"; } 398 399 // Check that the klass is assignable to a type with the given signature. 400 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 401 }; 402 403 class VM_GetReceiver : public VM_GetOrSetLocal { 404 protected: 405 virtual bool getting_receiver() const { return true; } 406 407 public: 408 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); 409 const char* name() const { return "get receiver"; } 410 }; 411 412 413 /////////////////////////////////////////////////////////////// 414 // 415 // class JvmtiSuspendControl 416 // 417 // Convenience routines for suspending and resuming threads. 418 // 419 // All attempts by JVMTI to suspend and resume threads must go through the 420 // JvmtiSuspendControl interface. 421 // 422 // methods return true if successful 423 // 424 class JvmtiSuspendControl : public AllStatic { 425 public: 426 // suspend the thread, taking it to a safepoint 427 static bool suspend(JavaThread *java_thread); 428 // resume the thread 429 static bool resume(JavaThread *java_thread); 430 431 static void print(); 432 }; 433 434 #endif // !JVMTI_KERNEL 435 436 /** 437 * When a thread (such as the compiler thread or VM thread) cannot post a 438 * JVMTI event itself because the event needs to be posted from a Java 439 * thread, then it can defer the event to the Service thread for posting. 440 * The information needed to post the event is encapsulated into this class 441 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 442 * thread will pick it up and post it. 443 * 444 * This is currently only used for posting compiled-method-load and unload 445 * events, which we don't want posted from the compiler thread. 446 */ 447 class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { 448 friend class JvmtiDeferredEventQueue; 449 private: 450 typedef enum { 451 TYPE_NONE, 452 TYPE_COMPILED_METHOD_LOAD, 453 TYPE_COMPILED_METHOD_UNLOAD, 454 TYPE_DYNAMIC_CODE_GENERATED 455 } Type; 456 457 Type _type; 458 union { 459 nmethod* compiled_method_load; 460 struct { 461 nmethod* nm; 462 jmethodID method_id; 463 const void* code_begin; 464 } compiled_method_unload; 465 struct { 466 const char* name; 467 const void* code_begin; 468 const void* code_end; 469 } dynamic_code_generated; 470 } _event_data; 471 472 JvmtiDeferredEvent(Type t) : _type(t) {} 473 474 public: 475 476 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 477 478 // Factory methods 479 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 480 KERNEL_RETURN_(JvmtiDeferredEvent()); 481 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm, 482 jmethodID id, const void* code) KERNEL_RETURN_(JvmtiDeferredEvent()); 483 static JvmtiDeferredEvent dynamic_code_generated_event( 484 const char* name, const void* begin, const void* end) 485 KERNEL_RETURN_(JvmtiDeferredEvent()); 486 487 // Actually posts the event. 488 void post() KERNEL_RETURN; 489 }; 490 491 /** 492 * Events enqueued on this queue wake up the Service thread which dequeues 493 * and posts the events. The Service_lock is required to be held 494 * when operating on the queue (except for the "pending" events). 495 */ 496 class JvmtiDeferredEventQueue : AllStatic { 497 friend class JvmtiDeferredEvent; 498 private: 499 class QueueNode : public CHeapObj { 500 private: 501 JvmtiDeferredEvent _event; 502 QueueNode* _next; 503 504 public: 505 QueueNode(const JvmtiDeferredEvent& event) 506 : _event(event), _next(NULL) {} 507 508 const JvmtiDeferredEvent& event() const { return _event; } 509 QueueNode* next() const { return _next; } 510 511 void set_next(QueueNode* next) { _next = next; } 512 }; 513 514 static QueueNode* _queue_head; // Hold Service_lock to access 515 static QueueNode* _queue_tail; // Hold Service_lock to access 516 static volatile QueueNode* _pending_list; // Uses CAS for read/update 517 518 // Transfers events from the _pending_list to the _queue. 519 static void process_pending_events() KERNEL_RETURN; 520 521 public: 522 // Must be holding Service_lock when calling these 523 static bool has_events() KERNEL_RETURN_(false); 524 static void enqueue(const JvmtiDeferredEvent& event) KERNEL_RETURN; 525 static JvmtiDeferredEvent dequeue() KERNEL_RETURN_(JvmtiDeferredEvent()); 526 527 // Used to enqueue events without using a lock, for times (such as during 528 // safepoint) when we can't or don't want to lock the Service_lock. 529 // 530 // Events will be held off to the side until there's a call to 531 // dequeue(), enqueue(), or process_pending_events() (all of which require 532 // the holding of the Service_lock), and will be enqueued at that time. 533 static void add_pending_event(const JvmtiDeferredEvent&) KERNEL_RETURN; 534 }; 535 536 // Utility macro that checks for NULL pointers: 537 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 538 539 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP