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
43class JvmtiBreakpoint;
44class 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
66class GrowableElement : public CHeapObj<mtInternal> {
67public:
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
77class GrowableCache {
78
79private:
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
99public:
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
136class JvmtiBreakpointCache : public CHeapObj<mtInternal> {
137
138private:
139 GrowableCache _cache;
140
141public:
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
171typedef void (Method::*method_action)(int _bci);
172
173class JvmtiBreakpoint : public GrowableElement {
174private:
175 Method* _method;
176 int _bci;
177 Bytecodes::Code _orig_bytecode;
178 oop _class_holder; // keeps _method memory from being deallocated
179
180public:
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
234class JvmtiBreakpoints : public CHeapObj<mtInternal> {
235private:
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
248public:
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
276class JvmtiCurrentBreakpoints : public AllStatic {
277
278private:
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
293public:
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 static void oops_do(OopClosure* f);
301 static void metadata_do(void f(Metadata*)) NOT_JVMTI_RETURN;
302 static void gc_epilogue();
303};
304
305///////////////////////////////////////////////////////////////
306//
307// class VM_ChangeBreakpoints
308// Used by : JvmtiBreakpoints
309// Used by JVMTI methods: none directly.
310// Note: A Helper class.
311//
312// VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
313//
314
315class VM_ChangeBreakpoints : public VM_Operation {
316private:
317 JvmtiBreakpoints* _breakpoints;
318 int _operation;
319 JvmtiBreakpoint* _bp;
320
321public:
322 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1 };
323
324 VM_ChangeBreakpoints(int operation, JvmtiBreakpoint *bp) {
325 JvmtiBreakpoints& current_bps = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
326 _breakpoints = &current_bps;
327 _bp = bp;
328 _operation = operation;
329 assert(bp != NULL, "bp != NULL");
330 }
331
332 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
333 void doit();
334 void oops_do(OopClosure* f);
335 void metadata_do(void f(Metadata*));
336};
337
338
339///////////////////////////////////////////////////////////////
340// The get/set local operations must only be done by the VM thread
341// because the interpreter version needs to access oop maps, which can
342// only safely be done by the VM thread
343//
344// I'm told that in 1.5 oop maps are now protected by a lock and
345// we could get rid of the VM op
346// However if the VM op is removed then the target thread must
347// be suspended AND a lock will be needed to prevent concurrent
348// setting of locals to the same java thread. This lock is needed
349// to prevent compiledVFrames from trying to add deferred updates
350// to the thread simultaneously.
351//
352class VM_GetOrSetLocal : public VM_Operation {
353 protected:
354 JavaThread* _thread;
355 JavaThread* _calling_thread;
356 jint _depth;
357 jint _index;
358 BasicType _type;
359 jvalue _value;
360 javaVFrame* _jvf;
361 bool _set;
362
363 // It is possible to get the receiver out of a non-static native wrapper
364 // frame. Use VM_GetReceiver to do this.
365 virtual bool getting_receiver() const { return false; }
366
367 jvmtiError _result;
368
369 vframe* get_vframe();
370 javaVFrame* get_java_vframe();
371 bool check_slot_type_lvt(javaVFrame* vf);
372 bool check_slot_type_no_lvt(javaVFrame* vf);
373
374public:
375 // Constructor for non-object getter
376 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
377
378 // Constructor for object or non-object setter
379 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
380
381 // Constructor for object getter
382 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
383 int index);
384
385 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
386 jvalue value() { return _value; }
387 jvmtiError result() { return _result; }
388
389 bool doit_prologue();
390 void doit();
391 bool allow_nested_vm_operations() const;
392 const char* name() const { return "get/set locals"; }
393
394 // Check that the klass is assignable to a type with the given signature.
395 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
396};
397
398class VM_GetReceiver : public VM_GetOrSetLocal {
399 protected:
400 virtual bool getting_receiver() const { return true; }
401
402 public:
403 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
404 const char* name() const { return "get receiver"; }
405};
406
407
408///////////////////////////////////////////////////////////////
409//
410// class JvmtiSuspendControl
411//
412// Convenience routines for suspending and resuming threads.
413//
414// All attempts by JVMTI to suspend and resume threads must go through the
415// JvmtiSuspendControl interface.
416//
417// methods return true if successful
418//
419class JvmtiSuspendControl : public AllStatic {
420public:
421 // suspend the thread, taking it to a safepoint
422 static bool suspend(JavaThread *java_thread);
423 // resume the thread
424 static bool resume(JavaThread *java_thread);
425
426 static void print();
427};
428
429
430/**
431 * When a thread (such as the compiler thread or VM thread) cannot post a
432 * JVMTI event itself because the event needs to be posted from a Java
433 * thread, then it can defer the event to the Service thread for posting.
434 * The information needed to post the event is encapsulated into this class
435 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service
436 * thread will pick it up and post it.
437 *
438 * This is currently only used for posting compiled-method-load and unload
439 * events, which we don't want posted from the compiler thread.
440 */
441class JvmtiDeferredEvent {
442 friend class JvmtiDeferredEventQueue;
443 private:
444 typedef enum {
445 TYPE_NONE,
446 TYPE_COMPILED_METHOD_LOAD,
447 TYPE_COMPILED_METHOD_UNLOAD,
448 TYPE_DYNAMIC_CODE_GENERATED
449 } Type;
450
451 Type _type;
452 union {
453 nmethod* compiled_method_load;
454 struct {
455 nmethod* nm;
456 jmethodID method_id;
457 const void* code_begin;
458 } compiled_method_unload;
459 struct {
460 const char* name;
461 const void* code_begin;
462 const void* code_end;
463 } dynamic_code_generated;
464 } _event_data;
465
466 JvmtiDeferredEvent(Type t) : _type(t) {}
467
468 public:
469
470 JvmtiDeferredEvent() : _type(TYPE_NONE) {}
471
472 // Factory methods
473 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm)
474 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
475 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm,
476 jmethodID id, const void* code) NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
477 static JvmtiDeferredEvent dynamic_code_generated_event(
478 const char* name, const void* begin, const void* end)
479 NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
480
481 // Actually posts the event.
482 void post() NOT_JVMTI_RETURN;
483};
484
485/**
486 * Events enqueued on this queue wake up the Service thread which dequeues
487 * and posts the events. The Service_lock is required to be held
488 * when operating on the queue.
489 */
490class JvmtiDeferredEventQueue : AllStatic {
491 friend class JvmtiDeferredEvent;
492 private:
493 class QueueNode : public CHeapObj<mtInternal> {
494 private:
495 JvmtiDeferredEvent _event;
496 QueueNode* _next;
497
498 public:
499 QueueNode(const JvmtiDeferredEvent& event)
500 : _event(event), _next(NULL) {}
501
502 const JvmtiDeferredEvent& event() const { return _event; }
503 QueueNode* next() const { return _next; }
504
505 void set_next(QueueNode* next) { _next = next; }
506 };
507
508 static QueueNode* _queue_head; // Hold Service_lock to access
509 static QueueNode* _queue_tail; // Hold Service_lock to access
510
511 public:
512 // Must be holding Service_lock when calling these
513 static bool has_events() NOT_JVMTI_RETURN_(false);
514 static void enqueue(const JvmtiDeferredEvent& event) NOT_JVMTI_RETURN;
515 static JvmtiDeferredEvent dequeue() NOT_JVMTI_RETURN_(JvmtiDeferredEvent());
516};
517
518// Utility macro that checks for NULL pointers:
519#define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
520
521#endif // SHARE_PRIMS_JVMTIIMPL_HPP
522