1 /*
2 * Copyright (c) 1999, 2019, 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_PRIMS_JVMTIIMPL_HPP
26 #define SHARE_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 };
124
125
126 ///////////////////////////////////////////////////////////////
127 //
128 // class JvmtiBreakpointCache
129 // Used by : JvmtiBreakpoints
130 // Used by JVMTI methods: none directly.
131 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint
132 //
133
134 class JvmtiBreakpointCache : public CHeapObj<mtInternal> {
135
136 private:
137 GrowableCache _cache;
138
139 public:
140 JvmtiBreakpointCache() {}
141 ~JvmtiBreakpointCache() {}
142
143 void initialize(void *this_obj, void listener_fun(void *, address*) ) {
144 _cache.initialize(this_obj,listener_fun);
145 }
146
147 int length() { return _cache.length(); }
148 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); }
149 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); }
150 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); }
151 void remove (int index) { _cache.remove(index); }
152 void clear() { _cache.clear(); }
153 void oops_do(OopClosure* f) { _cache.oops_do(f); }
154 void metadata_do(void f(Metadata*)) { _cache.metadata_do(f); }
155 };
156
157
158 ///////////////////////////////////////////////////////////////
159 //
160 // class JvmtiBreakpoint
161 // Used by : JvmtiBreakpoints
162 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints
163 // Note: Extends GrowableElement for use in a GrowableCache
164 //
165 // A JvmtiBreakpoint describes a location (class, method, bci) to break at.
166 //
167
168 typedef void (Method::*method_action)(int _bci);
169
170 class JvmtiBreakpoint : public GrowableElement {
171 private:
172 Method* _method;
173 int _bci;
174 Bytecodes::Code _orig_bytecode;
175 oop _class_holder; // keeps _method memory from being deallocated
176
177 public:
178 JvmtiBreakpoint();
179 JvmtiBreakpoint(Method* m_method, jlocation location);
180 bool equals(JvmtiBreakpoint& bp);
181 bool lessThan(JvmtiBreakpoint &bp);
182 void copy(JvmtiBreakpoint& bp);
183 bool is_valid();
184 address getBcp() const;
185 void each_method_version_do(method_action meth_act);
186 void set();
187 void clear();
188 void print_on(outputStream* out) const;
189
190 Method* method() { return _method; }
191
192 // GrowableElement implementation
193 address getCacheValue() { return getBcp(); }
194 bool lessThan(GrowableElement* e) { Unimplemented(); return false; }
195 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }
196 void oops_do(OopClosure* f) {
197 // Mark the method loader as live so the Method* class loader doesn't get
198 // unloaded and Method* memory reclaimed.
199 f->do_oop(&_class_holder);
200 }
201 void metadata_do(void f(Metadata*)) {
202 // walk metadata to preserve for RedefineClasses
203 f(_method);
204 }
205
206 GrowableElement *clone() {
207 JvmtiBreakpoint *bp = new JvmtiBreakpoint();
208 bp->copy(*this);
209 return bp;
210 }
211 };
212
213
214 ///////////////////////////////////////////////////////////////
215 //
216 // class JvmtiBreakpoints
217 // Used by : JvmtiCurrentBreakpoints
218 // Used by JVMTI methods: none directly
219 // Note: A Helper class
220 //
221 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.
222 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.
223 //
224 // Because _bps is only modified at safepoints, its possible to always use the
225 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).
226 //
227 // It would be possible to make JvmtiBreakpoints a static class, but I've made it
228 // CHeap allocated to emphasize its similarity to JvmtiFramePops.
229 //
230
231 class JvmtiBreakpoints : public CHeapObj<mtInternal> {
232 private:
233
234 JvmtiBreakpointCache _bps;
235
236 // These should only be used by VM_ChangeBreakpoints
237 // to insure they only occur at safepoints.
238 // Todo: add checks for safepoint
239 friend class VM_ChangeBreakpoints;
240 void set_at_safepoint(JvmtiBreakpoint& bp);
241 void clear_at_safepoint(JvmtiBreakpoint& bp);
242
243 static void do_element(GrowableElement *e);
244
245 public:
246 JvmtiBreakpoints(void listener_fun(void *, address *));
247 ~JvmtiBreakpoints();
248
249 int length();
250 void oops_do(OopClosure* f);
251 void metadata_do(void f(Metadata*));
252 void print();
253
254 int set(JvmtiBreakpoint& bp);
255 int clear(JvmtiBreakpoint& bp);
256 void clearall_in_class_at_safepoint(Klass* klass);
257 };
258
259
260 ///////////////////////////////////////////////////////////////
261 //
262 // class JvmtiCurrentBreakpoints
263 //
264 // A static wrapper class for the JvmtiBreakpoints that provides:
265 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).
266 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,
267 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize
268 // JvmtiFramePops).
269 // 3. An oops_do entry point for GC'ing the breakpoint array.
270 //
271
272 class JvmtiCurrentBreakpoints : public AllStatic {
273
274 private:
275
276 // Current breakpoints, lazily initialized by get_jvmti_breakpoints();
277 static JvmtiBreakpoints *_jvmti_breakpoints;
278
279 // NULL terminated cache of byte-code pointers corresponding to current breakpoints.
280 // Updated only at safepoints (with listener_fun) when the cache is moved.
281 // It exists only to make is_breakpoint fast.
282 static address *_breakpoint_list;
283 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }
284 static inline address *get_breakpoint_list() { return _breakpoint_list; }
285
286 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.
287 static void listener_fun(void *this_obj, address *cache);
288
289 public:
290 static void initialize();
291 static void destroy();
292
293 // lazily create _jvmti_breakpoints and _breakpoint_list
294 static JvmtiBreakpoints& get_jvmti_breakpoints();
295
296 static void oops_do(OopClosure* f);
297 static void metadata_do(void f(Metadata*)) NOT_JVMTI_RETURN;
298 };
299
300 ///////////////////////////////////////////////////////////////
301 //
302 // class VM_ChangeBreakpoints
303 // Used by : JvmtiBreakpoints
304 // Used by JVMTI methods: none directly.
305 // Note: A Helper class.
306 //
307 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
308 //
309
310 class VM_ChangeBreakpoints : public VM_Operation {
311 private:
312 JvmtiBreakpoints* _breakpoints;
313 int _operation;
314 JvmtiBreakpoint* _bp;
315
316 public:
317 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 };
318
319 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) {
320 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
321 _breakpoints = ¤t_bps;
322 _bp = bp;
323 _operation = operation;
324 assert(bp != NULL, "bp != NULL");
325 }
326
327 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
328 void doit();
329 void oops_do(OopClosure* f);
330 void metadata_do(void f(Metadata*));
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_lvt(javaVFrame* vf);
367 bool check_slot_type_no_lvt(javaVFrame* vf);
368
369 public:
370 // Constructor for non-object getter
371 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
372
373 // Constructor for object or non-object setter
374 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
375
376 // Constructor for object getter
377 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
378 int index);
379
380 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
381 jvalue value() { return _value; }
382 jvmtiError result() { return _result; }
383
384 bool doit_prologue();
385 void doit();
386 bool allow_nested_vm_operations() const;
387 const char* name() const { return "get/set locals"; }
388
389 // Check that the klass is assignable to a type with the given signature.
390 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
391 };
392
393 class VM_GetReceiver : public VM_GetOrSetLocal {
394 protected:
395 virtual bool getting_receiver() const { return true; }
396
397 public:
398 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
399 const char* name() const { return "get receiver"; }
400 };
401
402
403 ///////////////////////////////////////////////////////////////
404 //
405 // class JvmtiSuspendControl
406 //
407 // Convenience routines for suspending and resuming threads.
408 //
409 // All attempts by JVMTI to suspend and resume threads must go through the
410 // JvmtiSuspendControl interface.
411 //
412 // methods return true if successful
413 //
414 class JvmtiSuspendControl : public AllStatic {
415 public:
416 // suspend the thread, taking it to a safepoint
417 static bool suspend(JavaThread *java_thread);
418 // resume the thread
419 static bool resume(JavaThread *java_thread);
420
421 static void print();
422 };
423
424
425 /**
426 * When a thread (such as the compiler thread or VM thread) cannot post a
427 * JVMTI event itself because the event needs to be posted from a Java
428 * thread, then it can defer the event to the Service thread for posting.
429 * The information needed to post the event is encapsulated into this class
430 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service
431 * thread will pick it up and post it.
432 *
433 * This is currently only used for posting compiled-method-load and unload
434 * events, which we don't want posted from the compiler thread.
435 */
436 class JvmtiDeferredEvent {
437 friend class JvmtiDeferredEventQueue;
438 private:
439 typedef enum {
440 TYPE_NONE,
441 TYPE_COMPILED_METHOD_LOAD,
442 TYPE_COMPILED_METHOD_UNLOAD,
443 TYPE_DYNAMIC_CODE_GENERATED,
444 TYPE_CLASS_UNLOADED
445 } Type;
446
447 Type _type;
448 union {
449 nmethod* compiled_method_load;
450 struct {
451 nmethod* nm;
452 jmethodID method_id;
453 const void* code_begin;
454 } compiled_method_unload;
455 struct {
456 const char* name;
457 const void* code_begin;
458 const void* code_end;
459 } dynamic_code_generated;
460 struct {
461 const char* name;
462 } class_unloaded;
463 } _event_data;
464
465 JvmtiDeferredEvent(Type t) : _type(t) {}
466
467 public:
468
469 JvmtiDeferredEvent() : _type(TYPE_NONE) {}
470
471 // Factory methods
472 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm)
473 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
474 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,
475 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
476 static JvmtiDeferredEvent dynamic_code_generated_event(
477 const char* name, const void* begin, const void* end)
478 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
479 static JvmtiDeferredEvent class_unload_event(
480 const char* name) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
481
482 // Actually posts the event.
483 void post() NOT_JVMTI_RETURN;
484 };
485
486 /**
487 * Events enqueued on this queue wake up the Service thread which dequeues
488 * and posts the events. The Service_lock is required to be held
489 * when operating on the queue.
490 */
491 class JvmtiDeferredEventQueue : AllStatic {
492 friend class JvmtiDeferredEvent;
493 private:
494 class QueueNode : public CHeapObj<mtInternal> {
495 private:
496 JvmtiDeferredEvent _event;
497 QueueNode* _next;
498
499 public:
500 QueueNode(const JvmtiDeferredEvent& event)
501 : _event(event), _next(NULL) {}
502
503 const JvmtiDeferredEvent& event() const { return _event; }
504 QueueNode* next() const { return _next; }
505
506 void set_next(QueueNode* next) { _next = next; }
507 };
508
509 static QueueNode* _queue_head; // Hold Service_lock to access
510 static QueueNode* _queue_tail; // Hold Service_lock to access
511
512 public:
513 // Must be holding Service_lock when calling these
514 static bool has_events() NOT_JVMTI_RETURN_(false);
515 static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN;
516 static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
517 };
518
519 // Utility macro that checks for NULL pointers:
520 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
521
522 #endif // SHARE_PRIMS_JVMTIIMPL_HPP