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