1 /*
2 * Copyright (c) 1999, 2013, 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
38 //
39 // Forward Declarations
40 //
41
42 class JvmtiBreakpoint;
43 class JvmtiBreakpoints;
44
45
46 ///////////////////////////////////////////////////////////////
47 //
48 // class GrowableCache, GrowableElement
49 // Used by : JvmtiBreakpointCache
50 // Used by JVMTI methods: none directly.
51 //
52 // GrowableCache is a permanent CHeap growable array of <GrowableElement *>
53 //
54 // In addition, the GrowableCache maintains a NULL terminated cache array of type address
55 // that's created from the element array using the function:
56 // address GrowableElement::getCacheValue().
57 //
58 // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated
59 // block of memory. Additionally, every time the cache changes its position in memory, the
60 // void (*_listener_fun)(void *this_obj, address* cache)
61 // gets called with the cache's new address. This gives the user of the GrowableCache a callback
62 // to update its pointer to the address cache.
63 //
64
65 class GrowableElement : public CHeapObj<mtInternal> {
66 public:
67 virtual address getCacheValue() =0;
68 virtual bool equals(GrowableElement* e) =0;
69 virtual bool lessThan(GrowableElement *e)=0;
70 virtual GrowableElement *clone() =0;
71 virtual void oops_do(OopClosure* f) =0;
72 };
73
74 class GrowableCache VALUE_OBJ_CLASS_SPEC {
75
76 private:
77 // Object pointer passed into cache & listener functions.
78 void *_this_obj;
79
80 // Array of elements in the collection
81 GrowableArray<GrowableElement *> *_elements;
82
83 // Parallel array of cached values
84 address *_cache;
85
86 // Listener for changes to the _cache field.
87 // Called whenever the _cache field has it's value changed
88 // (but NOT when cached elements are recomputed).
89 void (*_listener_fun)(void *, address*);
90
91 static bool equals(void *, GrowableElement *);
92
93 // recache all elements after size change, notify listener
94 void recache();
95
96 public:
97 GrowableCache();
98 ~GrowableCache();
99
100 void initialize(void *this_obj, void listener_fun(void *, address*) );
101
102 // number of elements in the collection
103 int length();
104 // get the value of the index element in the collection
105 GrowableElement* at(int index);
106 // find the index of the element, -1 if it doesn't exist
107 int find(GrowableElement* e);
108 // append a copy of the element to the end of the collection, notify listener
109 void append(GrowableElement* e);
110 // insert a copy of the element using lessthan(), notify listener
111 void insert(GrowableElement* e);
112 // remove the element at index, notify listener
113 void remove (int index);
114 // clear out all elements and release all heap space, notify listener
115 void clear();
116 // apply f to every element and update the cache
117 void oops_do(OopClosure* f);
118 // update the cache after a full gc
119 void gc_epilogue();
120 };
121
122
123 ///////////////////////////////////////////////////////////////
124 //
125 // class JvmtiBreakpointCache
126 // Used by : JvmtiBreakpoints
127 // Used by JVMTI methods: none directly.
128 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint
129 //
130
131 class JvmtiBreakpointCache : public CHeapObj<mtInternal> {
132
133 private:
134 GrowableCache _cache;
135
136 public:
137 JvmtiBreakpointCache() {}
138 ~JvmtiBreakpointCache() {}
139
140 void initialize(void *this_obj, void listener_fun(void *, address*) ) {
141 _cache.initialize(this_obj,listener_fun);
142 }
143
144 int length() { return _cache.length(); }
145 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); }
146 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); }
147 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); }
148 void remove (int index) { _cache.remove(index); }
149 void clear() { _cache.clear(); }
150 void oops_do(OopClosure* f) { _cache.oops_do(f); }
151 void gc_epilogue() { _cache.gc_epilogue(); }
152 };
153
154
155 ///////////////////////////////////////////////////////////////
156 //
157 // class JvmtiBreakpoint
158 // Used by : JvmtiBreakpoints
159 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints
160 // Note: Extends GrowableElement for use in a GrowableCache
161 //
162 // A JvmtiBreakpoint describes a location (class, method, bci) to break at.
163 //
164
165 typedef void (methodOopDesc::*method_action)(int _bci);
166
167 class JvmtiBreakpoint : public GrowableElement {
168 private:
169 methodOop _method;
170 int _bci;
171 Bytecodes::Code _orig_bytecode;
172
173 public:
174 JvmtiBreakpoint();
175 JvmtiBreakpoint(methodOop m_method, jlocation location);
176 bool equals(JvmtiBreakpoint& bp);
177 bool lessThan(JvmtiBreakpoint &bp);
178 void copy(JvmtiBreakpoint& bp);
179 bool is_valid();
180 address getBcp();
181 void each_method_version_do(method_action meth_act);
182 void set();
183 void clear();
184 void print();
185
186 methodOop method() { return _method; }
187
188 // GrowableElement implementation
189 address getCacheValue() { return getBcp(); }
190 bool lessThan(GrowableElement* e) { Unimplemented(); return false; }
191 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }
192 void oops_do(OopClosure* f) { f->do_oop((oop *) &_method); }
193 GrowableElement *clone() {
194 JvmtiBreakpoint *bp = new JvmtiBreakpoint();
195 bp->copy(*this);
196 return bp;
197 }
198 };
199
200
201 ///////////////////////////////////////////////////////////////
202 //
203 // class JvmtiBreakpoints
204 // Used by : JvmtiCurrentBreakpoints
205 // Used by JVMTI methods: none directly
206 // Note: A Helper class
207 //
208 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.
209 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.
210 //
211 // Because _bps is only modified at safepoints, its possible to always use the
212 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).
213 //
214 // It would be possible to make JvmtiBreakpoints a static class, but I've made it
215 // CHeap allocated to emphasize its similarity to JvmtiFramePops.
216 //
217
218 class JvmtiBreakpoints : public CHeapObj<mtInternal> {
219 private:
220
221 JvmtiBreakpointCache _bps;
222
223 // These should only be used by VM_ChangeBreakpoints
224 // to insure they only occur at safepoints.
225 // Todo: add checks for safepoint
226 friend class VM_ChangeBreakpoints;
227 void set_at_safepoint(JvmtiBreakpoint& bp);
228 void clear_at_safepoint(JvmtiBreakpoint& bp);
229
230 static void do_element(GrowableElement *e);
231
232 public:
233 JvmtiBreakpoints(void listener_fun(void *, address *));
234 ~JvmtiBreakpoints();
235
236 int length();
237 void oops_do(OopClosure* f);
238 void print();
239
240 int set(JvmtiBreakpoint& bp);
241 int clear(JvmtiBreakpoint& bp);
242 void clearall_in_class_at_safepoint(klassOop klass);
243 void gc_epilogue();
244 };
245
246
247 ///////////////////////////////////////////////////////////////
248 //
249 // class JvmtiCurrentBreakpoints
250 //
251 // A static wrapper class for the JvmtiBreakpoints that provides:
252 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).
253 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,
254 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize
255 // JvmtiFramePops).
256 // 3. An oops_do entry point for GC'ing the breakpoint array.
257 //
258
259 class JvmtiCurrentBreakpoints : public AllStatic {
260
261 private:
262
263 // Current breakpoints, lazily initialized by get_jvmti_breakpoints();
264 static JvmtiBreakpoints *_jvmti_breakpoints;
265
266 // NULL terminated cache of byte-code pointers corresponding to current breakpoints.
267 // Updated only at safepoints (with listener_fun) when the cache is moved.
268 // It exists only to make is_breakpoint fast.
269 static address *_breakpoint_list;
270 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }
271 static inline address *get_breakpoint_list() { return _breakpoint_list; }
272
273 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.
274 static void listener_fun(void *this_obj, address *cache);
275
276 public:
277 static void initialize();
278 static void destroy();
279
280 // lazily create _jvmti_breakpoints and _breakpoint_list
281 static JvmtiBreakpoints& get_jvmti_breakpoints();
282
283 // quickly test whether the bcp matches a cached breakpoint in the list
284 static inline bool is_breakpoint(address bcp);
285
286 static void oops_do(OopClosure* f);
287 static void gc_epilogue();
288 };
289
290 // quickly test whether the bcp matches a cached breakpoint in the list
291 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) {
292 address *bps = get_breakpoint_list();
293 if (bps == NULL) return false;
294 for ( ; (*bps) != NULL; bps++) {
295 if ((*bps) == bcp) return true;
296 }
297 return false;
298 }
299
300
301 ///////////////////////////////////////////////////////////////
302 //
303 // class VM_ChangeBreakpoints
304 // Used by : JvmtiBreakpoints
305 // Used by JVMTI methods: none directly.
306 // Note: A Helper class.
307 //
308 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
309 //
310
311 class VM_ChangeBreakpoints : public VM_Operation {
312 private:
313 JvmtiBreakpoints* _breakpoints;
314 int _operation;
315 JvmtiBreakpoint* _bp;
316
317 public:
318 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 };
319
320 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) {
321 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
322 _breakpoints = ¤t_bps;
323 _bp = bp;
324 _operation = operation;
325 assert(bp != NULL, "bp != NULL");
326 }
327
328 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
329 void doit();
330 void oops_do(OopClosure* f);
331 };
332
333
334 ///////////////////////////////////////////////////////////////
335 // The get/set local operations must only be done by the VM thread
336 // because the interpreter version needs to access oop maps, which can
337 // only safely be done by the VM thread
338 //
339 // I'm told that in 1.5 oop maps are now protected by a lock and
340 // we could get rid of the VM op
341 // However if the VM op is removed then the target thread must
342 // be suspended AND a lock will be needed to prevent concurrent
343 // setting of locals to the same java thread. This lock is needed
344 // to prevent compiledVFrames from trying to add deferred updates
345 // to the thread simultaneously.
346 //
347 class VM_GetOrSetLocal : public VM_Operation {
348 protected:
349 JavaThread* _thread;
350 JavaThread* _calling_thread;
351 jint _depth;
352 jint _index;
353 BasicType _type;
354 jvalue _value;
355 javaVFrame* _jvf;
356 bool _set;
357
358 // It is possible to get the receiver out of a non-static native wrapper
359 // frame. Use VM_GetReceiver to do this.
360 virtual bool getting_receiver() const { return false; }
361
362 jvmtiError _result;
363
364 vframe* get_vframe();
365 javaVFrame* get_java_vframe();
366 bool check_slot_type(javaVFrame* vf);
367
368 public:
369 // Constructor for non-object getter
370 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
371
372 // Constructor for object or non-object setter
373 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
374
375 // Constructor for object getter
376 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
377 int index);
378
379 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
380 jvalue value() { return _value; }
381 jvmtiError result() { return _result; }
382
383 bool doit_prologue();
384 void doit();
385 bool allow_nested_vm_operations() const;
386 const char* name() const { return "get/set locals"; }
387
388 // Check that the klass is assignable to a type with the given signature.
389 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
390 };
391
392 class VM_GetReceiver : public VM_GetOrSetLocal {
393 protected:
394 virtual bool getting_receiver() const { return true; }
395
396 public:
397 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
398 const char* name() const { return "get receiver"; }
399 };
400
401
402 ///////////////////////////////////////////////////////////////
403 //
404 // class JvmtiSuspendControl
405 //
406 // Convenience routines for suspending and resuming threads.
407 //
408 // All attempts by JVMTI to suspend and resume threads must go through the
409 // JvmtiSuspendControl interface.
410 //
411 // methods return true if successful
412 //
413 class JvmtiSuspendControl : public AllStatic {
414 public:
415 // suspend the thread, taking it to a safepoint
416 static bool suspend(JavaThread *java_thread);
417 // resume the thread
418 static bool resume(JavaThread *java_thread);
419
420 static void print();
421 };
422
423
424 /**
425 * When a thread (such as the compiler thread or VM thread) cannot post a
426 * JVMTI event itself because the event needs to be posted from a Java
427 * thread, then it can defer the event to the Service thread for posting.
428 * The information needed to post the event is encapsulated into this class
429 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service
430 * thread will pick it up and post it.
431 *
432 * This is currently only used for posting compiled-method-load and unload
433 * events, which we don't want posted from the compiler thread.
434 */
435 class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC {
436 friend class JvmtiDeferredEventQueue;
437 private:
438 typedef enum {
439 TYPE_NONE,
440 TYPE_COMPILED_METHOD_LOAD,
441 TYPE_COMPILED_METHOD_UNLOAD,
442 TYPE_DYNAMIC_CODE_GENERATED
443 } Type;
444
445 Type _type;
446 union {
447 nmethod* compiled_method_load;
448 struct {
449 nmethod* nm;
450 jmethodID method_id;
451 const void* code_begin;
452 } compiled_method_unload;
453 struct {
454 const char* name;
455 const void* code_begin;
456 const void* code_end;
457 } dynamic_code_generated;
458 } _event_data;
459
460 JvmtiDeferredEvent(Type t) : _type(t) {}
461
462 public:
463
464 JvmtiDeferredEvent() : _type(TYPE_NONE) {}
465
466 // Factory methods
467 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm);
468 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,
469 jmethodID id, const void* code);
470 static JvmtiDeferredEvent dynamic_code_generated_event(
471 const char* name, const void* begin, const void* end);
472
473 // Actually posts the event.
474 void post();
475 };
476
477 /**
478 * Events enqueued on this queue wake up the Service thread which dequeues
479 * and posts the events. The Service_lock is required to be held
480 * when operating on the queue (except for the "pending" events).
481 */
482 class JvmtiDeferredEventQueue : AllStatic {
483 friend class JvmtiDeferredEvent;
484 private:
485 class QueueNode : public CHeapObj<mtInternal> {
486 private:
487 JvmtiDeferredEvent _event;
488 QueueNode* _next;
489
490 public:
491 QueueNode(const JvmtiDeferredEvent& event)
492 : _event(event), _next(NULL) {}
493
494 const JvmtiDeferredEvent& event() const { return _event; }
495 QueueNode* next() const { return _next; }
496
497 void set_next(QueueNode* next) { _next = next; }
498 };
499
500 static QueueNode* _queue_head; // Hold Service_lock to access
501 static QueueNode* _queue_tail; // Hold Service_lock to access
502 static volatile QueueNode* _pending_list; // Uses CAS for read/update
503
504 // Transfers events from the _pending_list to the _queue.
505 static void process_pending_events();
506
507 public:
508 // Must be holding Service_lock when calling these
509 static bool has_events();
510 static void enqueue(const JvmtiDeferredEvent& event);
511 static JvmtiDeferredEvent dequeue();
512
513 // Used to enqueue events without using a lock, for times (such as during
514 // safepoint) when we can't or don't want to lock the Service_lock.
515 //
516 // Events will be held off to the side until there's a call to
517 // dequeue(), enqueue(), or process_pending_events() (all of which require
518 // the holding of the Service_lock), and will be enqueued at that time.
519 static void add_pending_event(const JvmtiDeferredEvent&);
520 };
521
522 // Utility macro that checks for NULL pointers:
523 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
524
525 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP