1 /*
2 * Copyright (c) 1999, 2018, 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/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:
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
77 class GrowableCache {
78
79 private:
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
99 public:
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
136 class JvmtiBreakpointCache : public CHeapObj<mtInternal> {
137
138 private:
139 GrowableCache _cache;
140
141 public:
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
171 typedef void (Method::*method_action)(int _bci);
172
173 class JvmtiBreakpoint : public GrowableElement {
174 private:
175 Method* _method;
176 int _bci;
177 Bytecodes::Code _orig_bytecode;
178 oop _class_holder; // keeps _method memory from being deallocated
179
180 public:
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
234 class JvmtiBreakpoints : public CHeapObj<mtInternal> {
235 private:
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
248 public:
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
276 class JvmtiCurrentBreakpoints : public AllStatic {
277
278 private:
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
293 public:
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
309 bool 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
329 class VM_ChangeBreakpoints : public VM_Operation {
330 private:
331 JvmtiBreakpoints* _breakpoints;
332 int _operation;
333 JvmtiBreakpoint* _bp;
334
335 public:
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 //
366 class 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_lvt(javaVFrame* vf);
386 bool check_slot_type_no_lvt(javaVFrame* vf);
387
388 public:
389 // Constructor for non-object getter
390 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
391
392 // Constructor for object or non-object setter
393 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
394
395 // Constructor for object getter
396 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
397 int index);
398
399 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
400 jvalue value() { return _value; }
401 jvmtiError result() { return _result; }
402
403 bool doit_prologue();
404 void doit();
405 bool allow_nested_vm_operations() const;
406 const char* name() const { return "get/set locals"; }
407
408 // Check that the klass is assignable to a type with the given signature.
409 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
410 };
411
412 class VM_GetReceiver : public VM_GetOrSetLocal {
413 protected:
414 virtual bool getting_receiver() const { return true; }
415
416 public:
417 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
418 const char* name() const { return "get receiver"; }
419 };
420
421
422 ///////////////////////////////////////////////////////////////
423 //
424 // class JvmtiSuspendControl
425 //
426 // Convenience routines for suspending and resuming threads.
427 //
428 // All attempts by JVMTI to suspend and resume threads must go through the
429 // JvmtiSuspendControl interface.
430 //
431 // methods return true if successful
432 //
433 class JvmtiSuspendControl : public AllStatic {
434 public:
435 // suspend the thread, taking it to a safepoint
436 static bool suspend(JavaThread *java_thread);
437 // resume the thread
438 static bool resume(JavaThread *java_thread);
439
440 static void print();
441 };
442
443
444 /**
445 * When a thread (such as the compiler thread or VM thread) cannot post a
446 * JVMTI event itself because the event needs to be posted from a Java
447 * thread, then it can defer the event to the Service thread for posting.
448 * The information needed to post the event is encapsulated into this class
449 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service
450 * thread will pick it up and post it.
451 *
452 * This is currently only used for posting compiled-method-load and unload
453 * events, which we don't want posted from the compiler thread.
454 */
455 class JvmtiDeferredEvent {
456 friend class JvmtiDeferredEventQueue;
457 private:
458 typedef enum {
459 TYPE_NONE,
460 TYPE_COMPILED_METHOD_LOAD,
461 TYPE_COMPILED_METHOD_UNLOAD,
462 TYPE_DYNAMIC_CODE_GENERATED
463 } Type;
464
465 Type _type;
466 union {
467 nmethod* compiled_method_load;
468 struct {
469 nmethod* nm;
470 jmethodID method_id;
471 const void* code_begin;
472 } compiled_method_unload;
473 struct {
474 const char* name;
475 const void* code_begin;
476 const void* code_end;
477 } dynamic_code_generated;
478 } _event_data;
479
480 JvmtiDeferredEvent(Type t) : _type(t) {}
481
482 public:
483
484 JvmtiDeferredEvent() : _type(TYPE_NONE) {}
485
486 // Factory methods
487 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm)
488 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
489 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,
490 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
491 static JvmtiDeferredEvent dynamic_code_generated_event(
492 const char* name, const void* begin, const void* end)
493 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
494
495 // Actually posts the event.
496 void post() NOT_JVMTI_RETURN;
497 };
498
499 /**
500 * Events enqueued on this queue wake up the Service thread which dequeues
501 * and posts the events. The Service_lock is required to be held
502 * when operating on the queue.
503 */
504 class JvmtiDeferredEventQueue : AllStatic {
505 friend class JvmtiDeferredEvent;
506 private:
507 class QueueNode : public CHeapObj<mtInternal> {
508 private:
509 JvmtiDeferredEvent _event;
510 QueueNode* _next;
511
512 public:
513 QueueNode(const JvmtiDeferredEvent& event)
514 : _event(event), _next(NULL) {}
515
516 const JvmtiDeferredEvent& event() const { return _event; }
517 QueueNode* next() const { return _next; }
518
519 void set_next(QueueNode* next) { _next = next; }
520 };
521
522 static QueueNode* _queue_head; // Hold Service_lock to access
523 static QueueNode* _queue_tail; // Hold Service_lock to access
524
525 public:
526 // Must be holding Service_lock when calling these
527 static bool has_events() NOT_JVMTI_RETURN_(false);
528 static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN;
529 static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
530 };
531
532 // Utility macro that checks for NULL pointers:
533 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
534
535 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP