1/* 2 * Copyright (c) 1999, 2017, 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#include "utilities/ostream.hpp" 38 39// 40// Forward Declarations 41// 42 43class JvmtiBreakpoint; 44class 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 66class GrowableElement : public CHeapObj<mtInternal> { 67public: 68 virtual ~GrowableElement() {} 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 virtual void metadata_do(void f(Metadata*)) =0; 75}; 76 77class GrowableCache VALUE_OBJ_CLASS_SPEC { 78 79private: 80 // Object pointer passed into cache & listener functions. 81 void *_this_obj; 82 83 // Array of elements in the collection 84 GrowableArray<GrowableElement *> *_elements; 85 86 // Parallel array of cached values 87 address *_cache; 88 89 // Listener for changes to the _cache field. 90 // Called whenever the _cache field has it's value changed 91 // (but NOT when cached elements are recomputed). 92 void (*_listener_fun)(void *, address*); 93 94 static bool equals(void *, GrowableElement *); 95 96 // recache all elements after size change, notify listener 97 void recache(); 98 99public: 100 GrowableCache(); 101 ~GrowableCache(); 102 103 void initialize(void *this_obj, void listener_fun(void *, address*) ); 104 105 // number of elements in the collection 106 int length(); 107 // get the value of the index element in the collection 108 GrowableElement* at(int index); 109 // find the index of the element, -1 if it doesn't exist 110 int find(GrowableElement* e); 111 // append a copy of the element to the end of the collection, notify listener 112 void append(GrowableElement* e); 113 // insert a copy of the element using lessthan(), notify listener 114 void insert(GrowableElement* e); 115 // remove the element at index, notify listener 116 void remove (int index); 117 // clear out all elements and release all heap space, notify listener 118 void clear(); 119 // apply f to every element and update the cache 120 void oops_do(OopClosure* f); 121 // walk metadata to preserve for RedefineClasses 122 void metadata_do(void f(Metadata*)); 123 // update the cache after a full gc 124 void gc_epilogue(); 125}; 126 127 128/////////////////////////////////////////////////////////////// 129// 130// class JvmtiBreakpointCache 131// Used by : JvmtiBreakpoints 132// Used by JVMTI methods: none directly. 133// Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 134// 135 136class JvmtiBreakpointCache : public CHeapObj<mtInternal> { 137 138private: 139 GrowableCache _cache; 140 141public: 142 JvmtiBreakpointCache() {} 143 ~JvmtiBreakpointCache() {} 144 145 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 146 _cache.initialize(this_obj,listener_fun); 147 } 148 149 int length() { return _cache.length(); } 150 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } 151 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } 152 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } 153 void remove (int index) { _cache.remove(index); } 154 void clear() { _cache.clear(); } 155 void oops_do(OopClosure* f) { _cache.oops_do(f); } 156 void metadata_do(void f(Metadata*)) { _cache.metadata_do(f); } 157 void gc_epilogue() { _cache.gc_epilogue(); } 158}; 159 160 161/////////////////////////////////////////////////////////////// 162// 163// class JvmtiBreakpoint 164// Used by : JvmtiBreakpoints 165// Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 166// Note: Extends GrowableElement for use in a GrowableCache 167// 168// A JvmtiBreakpoint describes a location (class, method, bci) to break at. 169// 170 171typedef void (Method::*method_action)(int _bci); 172 173class JvmtiBreakpoint : public GrowableElement { 174private: 175 Method* _method; 176 int _bci; 177 Bytecodes::Code _orig_bytecode; 178 oop _class_holder; // keeps _method memory from being deallocated 179 180public: 181 JvmtiBreakpoint(); 182 JvmtiBreakpoint(Method* m_method, jlocation location); 183 bool equals(JvmtiBreakpoint& bp); 184 bool lessThan(JvmtiBreakpoint &bp); 185 void copy(JvmtiBreakpoint& bp); 186 bool is_valid(); 187 address getBcp() const; 188 void each_method_version_do(method_action meth_act); 189 void set(); 190 void clear(); 191 void print_on(outputStream* out) const; 192 193 Method* method() { return _method; } 194 195 // GrowableElement implementation 196 address getCacheValue() { return getBcp(); } 197 bool lessThan(GrowableElement* e) { Unimplemented(); return false; } 198 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 199 void oops_do(OopClosure* f) { 200 // Mark the method loader as live so the Method* class loader doesn't get 201 // unloaded and Method* memory reclaimed. 202 f->do_oop(&_class_holder); 203 } 204 void metadata_do(void f(Metadata*)) { 205 // walk metadata to preserve for RedefineClasses 206 f(_method); 207 } 208 209 GrowableElement *clone() { 210 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 211 bp->copy(*this); 212 return bp; 213 } 214}; 215 216 217/////////////////////////////////////////////////////////////// 218// 219// class JvmtiBreakpoints 220// Used by : JvmtiCurrentBreakpoints 221// Used by JVMTI methods: none directly 222// Note: A Helper class 223// 224// JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 225// All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 226// 227// Because _bps is only modified at safepoints, its possible to always use the 228// cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 229// 230// It would be possible to make JvmtiBreakpoints a static class, but I've made it 231// CHeap allocated to emphasize its similarity to JvmtiFramePops. 232// 233 234class JvmtiBreakpoints : public CHeapObj<mtInternal> { 235private: 236 237 JvmtiBreakpointCache _bps; 238 239 // These should only be used by VM_ChangeBreakpoints 240 // to insure they only occur at safepoints. 241 // Todo: add checks for safepoint 242 friend class VM_ChangeBreakpoints; 243 void set_at_safepoint(JvmtiBreakpoint& bp); 244 void clear_at_safepoint(JvmtiBreakpoint& bp); 245 246 static void do_element(GrowableElement *e); 247 248public: 249 JvmtiBreakpoints(void listener_fun(void *, address *)); 250 ~JvmtiBreakpoints(); 251 252 int length(); 253 void oops_do(OopClosure* f); 254 void metadata_do(void f(Metadata*)); 255 void print(); 256 257 int set(JvmtiBreakpoint& bp); 258 int clear(JvmtiBreakpoint& bp); 259 void clearall_in_class_at_safepoint(Klass* klass); 260 void gc_epilogue(); 261}; 262 263 264/////////////////////////////////////////////////////////////// 265// 266// class JvmtiCurrentBreakpoints 267// 268// A static wrapper class for the JvmtiBreakpoints that provides: 269// 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 270// 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 271// but I'm copying the code from JvmtiThreadState which needs to lazily initialize 272// JvmtiFramePops). 273// 3. An oops_do entry point for GC'ing the breakpoint array. 274// 275 276class JvmtiCurrentBreakpoints : public AllStatic { 277 278private: 279 280 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 281 static JvmtiBreakpoints *_jvmti_breakpoints; 282 283 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 284 // Updated only at safepoints (with listener_fun) when the cache is moved. 285 // It exists only to make is_breakpoint fast. 286 static address *_breakpoint_list; 287 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 288 static inline address *get_breakpoint_list() { return _breakpoint_list; } 289 290 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 291 static void listener_fun(void *this_obj, address *cache); 292 293public: 294 static void initialize(); 295 static void destroy(); 296 297 // lazily create _jvmti_breakpoints and _breakpoint_list 298 static JvmtiBreakpoints& get_jvmti_breakpoints(); 299 300 // quickly test whether the bcp matches a cached breakpoint in the list 301 static inline bool is_breakpoint(address bcp); 302 303 static void oops_do(OopClosure* f); 304 static void metadata_do(void f(Metadata*)) NOT_JVMTI_RETURN; 305 static void gc_epilogue(); 306}; 307 308// quickly test whether the bcp matches a cached breakpoint in the list 309bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) { 310 address *bps = get_breakpoint_list(); 311 if (bps == NULL) return false; 312 for ( ; (*bps) != NULL; bps++) { 313 if ((*bps) == bcp) return true; 314 } 315 return false; 316} 317 318 319/////////////////////////////////////////////////////////////// 320// 321// class VM_ChangeBreakpoints 322// Used by : JvmtiBreakpoints 323// Used by JVMTI methods: none directly. 324// Note: A Helper class. 325// 326// VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 327// 328 329class VM_ChangeBreakpoints : public VM_Operation { 330private: 331 JvmtiBreakpoints* _breakpoints; 332 int _operation; 333 JvmtiBreakpoint* _bp; 334 335public: 336 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 }; 337 338 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) { 339 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); 340 _breakpoints = ¤t_bps; 341 _bp = bp; 342 _operation = operation; 343 assert(bp != NULL, "bp != NULL"); 344 } 345 346 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 347 void doit(); 348 void oops_do(OopClosure* f); 349 void metadata_do(void f(Metadata*)); 350}; 351 352 353/////////////////////////////////////////////////////////////// 354// The get/set local operations must only be done by the VM thread 355// because the interpreter version needs to access oop maps, which can 356// only safely be done by the VM thread 357// 358// I'm told that in 1.5 oop maps are now protected by a lock and 359// we could get rid of the VM op 360// However if the VM op is removed then the target thread must 361// be suspended AND a lock will be needed to prevent concurrent 362// setting of locals to the same java thread. This lock is needed 363// to prevent compiledVFrames from trying to add deferred updates 364// to the thread simultaneously. 365// 366class VM_GetOrSetLocal : public VM_Operation { 367 protected: 368 JavaThread* _thread; 369 JavaThread* _calling_thread; 370 jint _depth; 371 jint _index; 372 BasicType _type; 373 jvalue _value; 374 javaVFrame* _jvf; 375 bool _set; 376 377 // It is possible to get the receiver out of a non-static native wrapper 378 // frame. Use VM_GetReceiver to do this. 379 virtual bool getting_receiver() const { return false; } 380 381 jvmtiError _result; 382 383 vframe* get_vframe(); 384 javaVFrame* get_java_vframe(); 385 bool check_slot_type(javaVFrame* vf); 386 387public: 388 // Constructor for non-object getter 389 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 390 391 // Constructor for object or non-object setter 392 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 393 394 // Constructor for object getter 395 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 396 int index); 397 398 VMOp_Type type() const { return VMOp_GetOrSetLocal; } 399 jvalue value() { return _value; } 400 jvmtiError result() { return _result; } 401 402 bool doit_prologue(); 403 void doit(); 404 bool allow_nested_vm_operations() const; 405 const char* name() const { return "get/set locals"; } 406 407 // Check that the klass is assignable to a type with the given signature. 408 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 409}; 410 411class VM_GetReceiver : public VM_GetOrSetLocal { 412 protected: 413 virtual bool getting_receiver() const { return true; } 414 415 public: 416 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); 417 const char* name() const { return "get receiver"; } 418}; 419 420 421/////////////////////////////////////////////////////////////// 422// 423// class JvmtiSuspendControl 424// 425// Convenience routines for suspending and resuming threads. 426// 427// All attempts by JVMTI to suspend and resume threads must go through the 428// JvmtiSuspendControl interface. 429// 430// methods return true if successful 431// 432class JvmtiSuspendControl : public AllStatic { 433public: 434 // suspend the thread, taking it to a safepoint 435 static bool suspend(JavaThread *java_thread); 436 // resume the thread 437 static bool resume(JavaThread *java_thread); 438 439 static void print(); 440}; 441 442 443/** 444 * When a thread (such as the compiler thread or VM thread) cannot post a 445 * JVMTI event itself because the event needs to be posted from a Java 446 * thread, then it can defer the event to the Service thread for posting. 447 * The information needed to post the event is encapsulated into this class 448 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 449 * thread will pick it up and post it. 450 * 451 * This is currently only used for posting compiled-method-load and unload 452 * events, which we don't want posted from the compiler thread. 453 */ 454class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { 455 friend class JvmtiDeferredEventQueue; 456 private: 457 typedef enum { 458 TYPE_NONE, 459 TYPE_COMPILED_METHOD_LOAD, 460 TYPE_COMPILED_METHOD_UNLOAD, 461 TYPE_DYNAMIC_CODE_GENERATED 462 } Type; 463 464 Type _type; 465 union { 466 nmethod* compiled_method_load; 467 struct { 468 nmethod* nm; 469 jmethodID method_id; 470 const void* code_begin; 471 } compiled_method_unload; 472 struct { 473 const char* name; 474 const void* code_begin; 475 const void* code_end; 476 } dynamic_code_generated; 477 } _event_data; 478 479 JvmtiDeferredEvent(Type t) : _type(t) {} 480 481 public: 482 483 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 484 485 // Factory methods 486 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 487 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 488 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm, 489 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 490 static JvmtiDeferredEvent dynamic_code_generated_event( 491 const char* name, const void* begin, const void* end) 492 NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 493 494 // Actually posts the event. 495 void post() NOT_JVMTI_RETURN; 496}; 497 498/** 499 * Events enqueued on this queue wake up the Service thread which dequeues 500 * and posts the events. The Service_lock is required to be held 501 * when operating on the queue. 502 */ 503class JvmtiDeferredEventQueue : AllStatic { 504 friend class JvmtiDeferredEvent; 505 private: 506 class QueueNode : public CHeapObj<mtInternal> { 507 private: 508 JvmtiDeferredEvent _event; 509 QueueNode* _next; 510 511 public: 512 QueueNode(const JvmtiDeferredEvent& event) 513 : _event(event), _next(NULL) {} 514 515 const JvmtiDeferredEvent& event() const { return _event; } 516 QueueNode* next() const { return _next; } 517 518 void set_next(QueueNode* next) { _next = next; } 519 }; 520 521 static QueueNode* _queue_head; // Hold Service_lock to access 522 static QueueNode* _queue_tail; // Hold Service_lock to access 523 524 public: 525 // Must be holding Service_lock when calling these 526 static bool has_events() NOT_JVMTI_RETURN_(false); 527 static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN; 528 static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent()); 529}; 530 531// Utility macro that checks for NULL pointers: 532#define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 533 534#endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP 535