1 /*
2 * Copyright (c) 1999, 2012, 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<mtInternal> {
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<mtInternal> {
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 (Method::*method_action)(int _bci);
168
169 class JvmtiBreakpoint : public GrowableElement {
170 private:
171 Method* _method;
172 int _bci;
173 Bytecodes::Code _orig_bytecode;
174 oop _class_loader;
175
176 public:
177 JvmtiBreakpoint();
178 JvmtiBreakpoint(Method* m_method, jlocation location);
179 bool equals(JvmtiBreakpoint& bp);
180 bool lessThan(JvmtiBreakpoint &bp);
181 void copy(JvmtiBreakpoint& bp);
182 bool is_valid();
183 address getBcp();
184 void each_method_version_do(method_action meth_act);
185 void set();
186 void clear();
187 void print();
188
189 Method* method() { return _method; }
190
191 // GrowableElement implementation
192 address getCacheValue() { return getBcp(); }
193 bool lessThan(GrowableElement* e) { Unimplemented(); return false; }
194 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }
195 void oops_do(OopClosure* f) {
196 // Mark the method loader as live
197 f->do_oop(&_class_loader);
198 }
199 GrowableElement *clone() {
200 JvmtiBreakpoint *bp = new JvmtiBreakpoint();
201 bp->copy(*this);
202 return bp;
203 }
204 };
205
206
207 ///////////////////////////////////////////////////////////////
208 //
209 // class VM_ChangeBreakpoints
210 // Used by : JvmtiBreakpoints
211 // Used by JVMTI methods: none directly.
212 // Note: A Helper class.
213 //
214 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
215 //
216
217 class VM_ChangeBreakpoints : public VM_Operation {
218 private:
219 JvmtiBreakpoints* _breakpoints;
220 int _operation;
221 JvmtiBreakpoint* _bp;
222
223 public:
224 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1, CLEAR_ALL_BREAKPOINT=2 };
225
226 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation) {
227 _breakpoints = breakpoints;
228 _bp = NULL;
229 _operation = operation;
230 assert(breakpoints != NULL, "breakpoints != NULL");
231 assert(operation == CLEAR_ALL_BREAKPOINT, "unknown breakpoint operation");
232 }
233 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation, JvmtiBreakpoint *bp) {
234 _breakpoints = breakpoints;
235 _bp = bp;
236 _operation = operation;
237 assert(breakpoints != NULL, "breakpoints != NULL");
238 assert(bp != NULL, "bp != NULL");
239 assert(operation == SET_BREAKPOINT || operation == CLEAR_BREAKPOINT , "unknown breakpoint operation");
240 }
241
242 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
243 void doit();
244 void oops_do(OopClosure* f);
245 };
246
247
248 ///////////////////////////////////////////////////////////////
249 //
250 // class JvmtiBreakpoints
251 // Used by : JvmtiCurrentBreakpoints
252 // Used by JVMTI methods: none directly
253 // Note: A Helper class
254 //
255 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.
256 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.
257 //
258 // Because _bps is only modified at safepoints, its possible to always use the
259 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).
260 //
261 // It would be possible to make JvmtiBreakpoints a static class, but I've made it
262 // CHeap allocated to emphasize its similarity to JvmtiFramePops.
263 //
264
265 class JvmtiBreakpoints : public CHeapObj<mtInternal> {
266 private:
267
268 JvmtiBreakpointCache _bps;
269
270 // These should only be used by VM_ChangeBreakpoints
271 // to insure they only occur at safepoints.
272 // Todo: add checks for safepoint
273 friend class VM_ChangeBreakpoints;
274 void set_at_safepoint(JvmtiBreakpoint& bp);
275 void clear_at_safepoint(JvmtiBreakpoint& bp);
276 void clearall_at_safepoint();
277
278 static void do_element(GrowableElement *e);
279
280 public:
281 JvmtiBreakpoints(void listener_fun(void *, address *));
282 ~JvmtiBreakpoints();
283
284 int length();
285 void oops_do(OopClosure* f);
286 void print();
287
288 int set(JvmtiBreakpoint& bp);
289 int clear(JvmtiBreakpoint& bp);
290 void clearall_in_class_at_safepoint(Klass* klass);
291 void clearall();
292 void gc_epilogue();
293 };
294
295
296 ///////////////////////////////////////////////////////////////
297 //
298 // class JvmtiCurrentBreakpoints
299 //
300 // A static wrapper class for the JvmtiBreakpoints that provides:
301 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).
302 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,
303 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize
304 // JvmtiFramePops).
305 // 3. An oops_do entry point for GC'ing the breakpoint array.
306 //
307
308 class JvmtiCurrentBreakpoints : public AllStatic {
309
310 private:
311
312 // Current breakpoints, lazily initialized by get_jvmti_breakpoints();
313 static JvmtiBreakpoints *_jvmti_breakpoints;
314
315 // NULL terminated cache of byte-code pointers corresponding to current breakpoints.
316 // Updated only at safepoints (with listener_fun) when the cache is moved.
317 // It exists only to make is_breakpoint fast.
318 static address *_breakpoint_list;
319 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }
320 static inline address *get_breakpoint_list() { return _breakpoint_list; }
321
322 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.
323 static void listener_fun(void *this_obj, address *cache);
324
325 public:
326 static void initialize();
327 static void destroy();
328
329 // lazily create _jvmti_breakpoints and _breakpoint_list
330 static JvmtiBreakpoints& get_jvmti_breakpoints();
331
332 // quickly test whether the bcp matches a cached breakpoint in the list
333 static inline bool is_breakpoint(address bcp);
334
335 static void oops_do(OopClosure* f);
336 static void gc_epilogue();
337 };
338
339 // quickly test whether the bcp matches a cached breakpoint in the list
340 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) {
341 address *bps = get_breakpoint_list();
342 if (bps == NULL) return false;
343 for ( ; (*bps) != NULL; bps++) {
344 if ((*bps) == bcp) return true;
345 }
346 return false;
347 }
348
349 ///////////////////////////////////////////////////////////////
350 // The get/set local operations must only be done by the VM thread
351 // because the interpreter version needs to access oop maps, which can
352 // only safely be done by the VM thread
353 //
354 // I'm told that in 1.5 oop maps are now protected by a lock and
355 // we could get rid of the VM op
356 // However if the VM op is removed then the target thread must
357 // be suspended AND a lock will be needed to prevent concurrent
358 // setting of locals to the same java thread. This lock is needed
359 // to prevent compiledVFrames from trying to add deferred updates
360 // to the thread simultaneously.
361 //
362 class VM_GetOrSetLocal : public VM_Operation {
363 protected:
364 JavaThread* _thread;
365 JavaThread* _calling_thread;
366 jint _depth;
367 jint _index;
368 BasicType _type;
369 jvalue _value;
370 javaVFrame* _jvf;
371 bool _set;
372
373 // It is possible to get the receiver out of a non-static native wrapper
374 // frame. Use VM_GetReceiver to do this.
375 virtual bool getting_receiver() const { return false; }
376
377 jvmtiError _result;
378
379 vframe* get_vframe();
380 javaVFrame* get_java_vframe();
381 bool check_slot_type(javaVFrame* vf);
382
383 public:
384 // Constructor for non-object getter
385 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
386
387 // Constructor for object or non-object setter
388 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
389
390 // Constructor for object getter
391 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
392 int index);
393
394 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
395 jvalue value() { return _value; }
396 jvmtiError result() { return _result; }
397
398 bool doit_prologue();
399 void doit();
400 bool allow_nested_vm_operations() const;
401 const char* name() const { return "get/set locals"; }
402
403 // Check that the klass is assignable to a type with the given signature.
404 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
405 };
406
407 class VM_GetReceiver : public VM_GetOrSetLocal {
408 protected:
409 virtual bool getting_receiver() const { return true; }
410
411 public:
412 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
413 const char* name() const { return "get receiver"; }
414 };
415
416
417 ///////////////////////////////////////////////////////////////
418 //
419 // class JvmtiSuspendControl
420 //
421 // Convenience routines for suspending and resuming threads.
422 //
423 // All attempts by JVMTI to suspend and resume threads must go through the
424 // JvmtiSuspendControl interface.
425 //
426 // methods return true if successful
427 //
428 class JvmtiSuspendControl : public AllStatic {
429 public:
430 // suspend the thread, taking it to a safepoint
431 static bool suspend(JavaThread *java_thread);
432 // resume the thread
433 static bool resume(JavaThread *java_thread);
434
435 static void print();
436 };
437
438 #endif // !JVMTI_KERNEL
439
440 /**
441 * When a thread (such as the compiler thread or VM thread) cannot post a
442 * JVMTI event itself because the event needs to be posted from a Java
443 * thread, then it can defer the event to the Service thread for posting.
444 * The information needed to post the event is encapsulated into this class
445 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service
446 * thread will pick it up and post it.
447 *
448 * This is currently only used for posting compiled-method-load and unload
449 * events, which we don't want posted from the compiler thread.
450 */
451 class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC {
452 friend class JvmtiDeferredEventQueue;
453 private:
454 typedef enum {
455 TYPE_NONE,
456 TYPE_COMPILED_METHOD_LOAD,
457 TYPE_COMPILED_METHOD_UNLOAD,
458 TYPE_DYNAMIC_CODE_GENERATED
459 } Type;
460
461 Type _type;
462 union {
463 nmethod* compiled_method_load;
464 struct {
465 nmethod* nm;
466 jmethodID method_id;
467 const void* code_begin;
468 } compiled_method_unload;
469 struct {
470 const char* name;
471 const void* code_begin;
472 const void* code_end;
473 } dynamic_code_generated;
474 } _event_data;
475
476 JvmtiDeferredEvent(Type t) : _type(t) {}
477
478 public:
479
480 JvmtiDeferredEvent() : _type(TYPE_NONE) {}
481
482 // Factory methods
483 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm)
484 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
485 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,
486 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
487 static JvmtiDeferredEvent dynamic_code_generated_event(
488 const char* name, const void* begin, const void* end)
489 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
490
491 // Actually posts the event.
492 void post() NOT_JVMTI_RETURN;
493 };
494
495 /**
496 * Events enqueued on this queue wake up the Service thread which dequeues
497 * and posts the events. The Service_lock is required to be held
498 * when operating on the queue (except for the "pending" events).
499 */
500 class JvmtiDeferredEventQueue : AllStatic {
501 friend class JvmtiDeferredEvent;
502 private:
503 class QueueNode : public CHeapObj<mtInternal> {
504 private:
505 JvmtiDeferredEvent _event;
506 QueueNode* _next;
507
508 public:
509 QueueNode(const JvmtiDeferredEvent& event)
510 : _event(event), _next(NULL) {}
511
512 const JvmtiDeferredEvent& event() const { return _event; }
513 QueueNode* next() const { return _next; }
514
515 void set_next(QueueNode* next) { _next = next; }
516 };
517
518 static QueueNode* _queue_head; // Hold Service_lock to access
519 static QueueNode* _queue_tail; // Hold Service_lock to access
520 static volatile QueueNode* _pending_list; // Uses CAS for read/update
521
522 // Transfers events from the _pending_list to the _queue.
523 static void process_pending_events() NOT_JVMTI_RETURN;
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 // Used to enqueue events without using a lock, for times (such as during
532 // safepoint) when we can't or don't want to lock the Service_lock.
533 //
534 // Events will be held off to the side until there's a call to
535 // dequeue(), enqueue(), or process_pending_events() (all of which require
536 // the holding of the Service_lock), and will be enqueued at that time.
537 static void add_pending_event(const JvmtiDeferredEvent&) NOT_JVMTI_RETURN;
538 };
539
540 // Utility macro that checks for NULL pointers:
541 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
542
543 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP