1 /*
2 * Copyright (c) 1999, 2007, 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 //
26 // Forward Declarations
27 //
28
29 class JvmtiRawMonitor;
30 class JvmtiBreakpoint;
31 class JvmtiBreakpoints;
32
33
34 ///////////////////////////////////////////////////////////////
35 //
36 // class GrowableCache, GrowableElement
37 // Used by : JvmtiBreakpointCache
38 // Used by JVMTI methods: none directly.
39 //
40 // GrowableCache is a permanent CHeap growable array of <GrowableElement *>
41 //
42 // In addition, the GrowableCache maintains a NULL terminated cache array of type address
43 // that's created from the element array using the function:
44 // address GrowableElement::getCacheValue().
45 //
46 // Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated
47 // block of memory. Additionally, every time the cache changes its position in memory, the
48 // void (*_listener_fun)(void *this_obj, address* cache)
49 // gets called with the cache's new address. This gives the user of the GrowableCache a callback
50 // to update its pointer to the address cache.
51 //
52
53 class GrowableElement : public CHeapObj {
54 public:
55 virtual address getCacheValue() =0;
56 virtual bool equals(GrowableElement* e) =0;
57 virtual bool lessThan(GrowableElement *e)=0;
58 virtual GrowableElement *clone() =0;
59 virtual void oops_do(OopClosure* f) =0;
60 };
61
62 class GrowableCache VALUE_OBJ_CLASS_SPEC {
63
64 private:
65 // Object pointer passed into cache & listener functions.
66 void *_this_obj;
67
68 // Array of elements in the collection
69 GrowableArray<GrowableElement *> *_elements;
70
71 // Parallel array of cached values
72 address *_cache;
73
74 // Listener for changes to the _cache field.
75 // Called whenever the _cache field has it's value changed
76 // (but NOT when cached elements are recomputed).
77 void (*_listener_fun)(void *, address*);
78
79 static bool equals(void *, GrowableElement *);
80
81 // recache all elements after size change, notify listener
82 void recache();
83
84 public:
85 GrowableCache();
86 ~GrowableCache();
87
88 void initialize(void *this_obj, void listener_fun(void *, address*) );
89
90 // number of elements in the collection
91 int length();
92 // get the value of the index element in the collection
93 GrowableElement* at(int index);
94 // find the index of the element, -1 if it doesn't exist
95 int find(GrowableElement* e);
96 // append a copy of the element to the end of the collection, notify listener
97 void append(GrowableElement* e);
98 // insert a copy of the element using lessthan(), notify listener
99 void insert(GrowableElement* e);
100 // remove the element at index, notify listener
101 void remove (int index);
102 // clear out all elements and release all heap space, notify listener
103 void clear();
104 // apply f to every element and update the cache
105 void oops_do(OopClosure* f);
106 void gc_epilogue();
107 };
108
109
110 ///////////////////////////////////////////////////////////////
111 //
112 // class JvmtiBreakpointCache
113 // Used by : JvmtiBreakpoints
114 // Used by JVMTI methods: none directly.
115 // Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint
116 //
117
118 class JvmtiBreakpointCache : public CHeapObj {
119
120 private:
121 GrowableCache _cache;
122
123 public:
124 JvmtiBreakpointCache() {}
125 ~JvmtiBreakpointCache() {}
126
127 void initialize(void *this_obj, void listener_fun(void *, address*) ) {
128 _cache.initialize(this_obj,listener_fun);
129 }
130
131 int length() { return _cache.length(); }
132 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); }
133 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); }
134 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); }
135 void remove (int index) { _cache.remove(index); }
136 void clear() { _cache.clear(); }
137 void oops_do(OopClosure* f) { _cache.oops_do(f); }
138 void gc_epilogue() { _cache.gc_epilogue(); }
139 };
140
141
142 ///////////////////////////////////////////////////////////////
143 //
144 // class JvmtiBreakpoint
145 // Used by : JvmtiBreakpoints
146 // Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints
147 // Note: Extends GrowableElement for use in a GrowableCache
148 //
149 // A JvmtiBreakpoint describes a location (class, method, bci) to break at.
150 //
151
152 typedef void (methodOopDesc::*method_action)(int _bci);
153
154 class JvmtiBreakpoint : public GrowableElement {
155 private:
156 methodOop _method;
157 int _bci;
158 Bytecodes::Code _orig_bytecode;
159
160 public:
161 JvmtiBreakpoint();
162 JvmtiBreakpoint(methodOop m_method, jlocation location);
163 bool equals(JvmtiBreakpoint& bp);
164 bool lessThan(JvmtiBreakpoint &bp);
165 void copy(JvmtiBreakpoint& bp);
166 bool is_valid();
167 address getBcp();
168 void each_method_version_do(method_action meth_act);
169 void set();
170 void clear();
171 void print();
172
173 methodOop method() { return _method; }
174
175 // GrowableElement implementation
176 address getCacheValue() { return getBcp(); }
177 bool lessThan(GrowableElement* e) { Unimplemented(); return false; }
178 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }
179 void oops_do(OopClosure* f) { f->do_oop((oop *) &_method); }
180 GrowableElement *clone() {
181 JvmtiBreakpoint *bp = new JvmtiBreakpoint();
182 bp->copy(*this);
183 return bp;
184 }
185 };
186
187
188 ///////////////////////////////////////////////////////////////
189 //
190 // class VM_ChangeBreakpoints
191 // Used by : JvmtiBreakpoints
192 // Used by JVMTI methods: none directly.
193 // Note: A Helper class.
194 //
195 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
196 //
197
198 class VM_ChangeBreakpoints : public VM_Operation {
199 private:
200 JvmtiBreakpoints* _breakpoints;
201 int _operation;
202 JvmtiBreakpoint* _bp;
203
204 public:
205 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1, CLEAR_ALL_BREAKPOINT=2 };
206
207 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation) {
208 _breakpoints = breakpoints;
209 _bp = NULL;
210 _operation = operation;
211 assert(breakpoints != NULL, "breakpoints != NULL");
212 assert(operation == CLEAR_ALL_BREAKPOINT, "unknown breakpoint operation");
213 }
214 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation, JvmtiBreakpoint *bp) {
215 _breakpoints = breakpoints;
216 _bp = bp;
217 _operation = operation;
218 assert(breakpoints != NULL, "breakpoints != NULL");
219 assert(bp != NULL, "bp != NULL");
220 assert(operation == SET_BREAKPOINT || operation == CLEAR_BREAKPOINT , "unknown breakpoint operation");
221 }
222
223 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
224 void doit();
225 void oops_do(OopClosure* f);
226 };
227
228
229 ///////////////////////////////////////////////////////////////
230 //
231 // class JvmtiBreakpoints
232 // Used by : JvmtiCurrentBreakpoints
233 // Used by JVMTI methods: none directly
234 // Note: A Helper class
235 //
236 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.
237 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.
238 //
239 // Because _bps is only modified at safepoints, its possible to always use the
240 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).
241 //
242 // It would be possible to make JvmtiBreakpoints a static class, but I've made it
243 // CHeap allocated to emphasize its similarity to JvmtiFramePops.
244 //
245
246 class JvmtiBreakpoints : public CHeapObj {
247 private:
248
249 JvmtiBreakpointCache _bps;
250
251 // These should only be used by VM_ChangeBreakpoints
252 // to insure they only occur at safepoints.
253 // Todo: add checks for safepoint
254 friend class VM_ChangeBreakpoints;
255 void set_at_safepoint(JvmtiBreakpoint& bp);
256 void clear_at_safepoint(JvmtiBreakpoint& bp);
257 void clearall_at_safepoint();
258
259 static void do_element(GrowableElement *e);
260
261 public:
262 JvmtiBreakpoints(void listener_fun(void *, address *));
263 ~JvmtiBreakpoints();
264
265 int length();
266 void oops_do(OopClosure* f);
267 void gc_epilogue();
268 void print();
269
270 int set(JvmtiBreakpoint& bp);
271 int clear(JvmtiBreakpoint& bp);
272 void clearall_in_class_at_safepoint(klassOop klass);
273 void clearall();
274 };
275
276
277 ///////////////////////////////////////////////////////////////
278 //
279 // class JvmtiCurrentBreakpoints
280 //
281 // A static wrapper class for the JvmtiBreakpoints that provides:
282 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).
283 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,
284 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize
285 // JvmtiFramePops).
286 // 3. An oops_do entry point for GC'ing the breakpoint array.
287 //
288
289 class JvmtiCurrentBreakpoints : public AllStatic {
290
291 private:
292
293 // Current breakpoints, lazily initialized by get_jvmti_breakpoints();
294 static JvmtiBreakpoints *_jvmti_breakpoints;
295
296 // NULL terminated cache of byte-code pointers corresponding to current breakpoints.
297 // Updated only at safepoints (with listener_fun) when the cache is moved.
298 // It exists only to make is_breakpoint fast.
299 static address *_breakpoint_list;
300 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }
301 static inline address *get_breakpoint_list() { return _breakpoint_list; }
302
303 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.
304 static void listener_fun(void *this_obj, address *cache);
305
306 public:
307 static void initialize();
308 static void destroy();
309
310 // lazily create _jvmti_breakpoints and _breakpoint_list
311 static JvmtiBreakpoints& get_jvmti_breakpoints();
312
313 // quickly test whether the bcp matches a cached breakpoint in the list
314 static inline bool is_breakpoint(address bcp);
315
316 static void oops_do(OopClosure* f);
317 static void gc_epilogue();
318 };
319
320 // quickly test whether the bcp matches a cached breakpoint in the list
321 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) {
322 address *bps = get_breakpoint_list();
323 if (bps == NULL) return false;
324 for ( ; (*bps) != NULL; bps++) {
325 if ((*bps) == bcp) return true;
326 }
327 return false;
328 }
329
330
331 ///////////////////////////////////////////////////////////////
332 //
333 // class JvmtiRawMonitor
334 //
335 // Used by JVMTI methods: All RawMonitor methods (CreateRawMonitor, EnterRawMonitor, etc.)
336 //
337 // Wrapper for ObjectMonitor class that saves the Monitor's name
338 //
339
340 class JvmtiRawMonitor : public ObjectMonitor {
341 private:
342 int _magic;
343 char * _name;
344 // JVMTI_RM_MAGIC is set in contructor and unset in destructor.
345 enum { JVMTI_RM_MAGIC = (int)(('T' << 24) | ('I' << 16) | ('R' << 8) | 'M') };
346
347 public:
348 JvmtiRawMonitor(const char *name);
349 ~JvmtiRawMonitor();
350 int magic() { return _magic; }
351 const char *get_name() { return _name; }
352 bool is_valid();
353 };
354
355 // Onload pending raw monitors
356 // Class is used to cache onload or onstart monitor enter
357 // which will transition into real monitor when
358 // VM is fully initialized.
359 class JvmtiPendingMonitors : public AllStatic {
360
361 private:
362 static GrowableArray<JvmtiRawMonitor*> *_monitors; // Cache raw monitor enter
363
364 inline static GrowableArray<JvmtiRawMonitor*>* monitors() { return _monitors; }
365
366 static void dispose() {
367 delete monitors();
368 }
369
370 public:
371 static void enter(JvmtiRawMonitor *monitor) {
372 monitors()->append(monitor);
373 }
374
375 static int count() {
376 return monitors()->length();
377 }
378
379 static void destroy(JvmtiRawMonitor *monitor) {
380 while (monitors()->contains(monitor)) {
381 monitors()->remove(monitor);
382 }
383 }
384
385 // Return false if monitor is not found in the list.
386 static bool exit(JvmtiRawMonitor *monitor) {
387 if (monitors()->contains(monitor)) {
388 monitors()->remove(monitor);
389 return true;
390 } else {
391 return false;
392 }
393 }
394
395 static void transition_raw_monitors();
396 };
397
398
399
400 ///////////////////////////////////////////////////////////////
401 // The get/set local operations must only be done by the VM thread
402 // because the interpreter version needs to access oop maps, which can
403 // only safely be done by the VM thread
404 //
405 // I'm told that in 1.5 oop maps are now protected by a lock and
406 // we could get rid of the VM op
407 // However if the VM op is removed then the target thread must
408 // be suspended AND a lock will be needed to prevent concurrent
409 // setting of locals to the same java thread. This lock is needed
410 // to prevent compiledVFrames from trying to add deferred updates
411 // to the thread simultaneously.
412 //
413 class VM_GetOrSetLocal : public VM_Operation {
414 private:
415 JavaThread* _thread;
416 JavaThread* _calling_thread;
417 jint _depth;
418 jint _index;
419 BasicType _type;
420 jvalue _value;
421 javaVFrame* _jvf;
422 bool _set;
423
424 jvmtiError _result;
425
426 vframe* get_vframe();
427 javaVFrame* get_java_vframe();
428 bool check_slot_type(javaVFrame* vf);
429
430 public:
431 // Constructor for non-object getter
432 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
433
434 // Constructor for object or non-object setter
435 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
436
437 // Constructor for object getter
438 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
439 int index);
440
441 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
442 jvalue value() { return _value; }
443 jvmtiError result() { return _result; }
444
445 bool doit_prologue();
446 void doit();
447 bool allow_nested_vm_operations() const;
448 const char* name() const { return "get/set locals"; }
449
450 // Check that the klass is assignable to a type with the given signature.
451 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
452 };
453
454
455 ///////////////////////////////////////////////////////////////
456 //
457 // class JvmtiSuspendControl
458 //
459 // Convenience routines for suspending and resuming threads.
460 //
461 // All attempts by JVMTI to suspend and resume threads must go through the
462 // JvmtiSuspendControl interface.
463 //
464 // methods return true if successful
465 //
466 class JvmtiSuspendControl : public AllStatic {
467 public:
468 // suspend the thread, taking it to a safepoint
469 static bool suspend(JavaThread *java_thread);
470 // resume the thread
471 static bool resume(JavaThread *java_thread);
472
473 static void print();
474 };
475
476 // Utility macro that checks for NULL pointers:
477 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }