Wed, 19 Jan 2011 13:51:53 -0800
7012505: BreakpointWithFullGC.sh fails with Internal Error (src/share/vm/oops/methodOop.cpp:220)
Summary: Rebuild breakpoint cache at gc_epilogue instead of during oops_do
Reviewed-by: dcubed, ysr, coleenp
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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25 #ifndef SHARE_VM_PRIMS_JVMTIIMPL_HPP
26 #define SHARE_VM_PRIMS_JVMTIIMPL_HPP
28 #ifndef JVMTI_KERNEL
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"
40 //
41 // Forward Declarations
42 //
44 class JvmtiBreakpoint;
45 class JvmtiBreakpoints;
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 //
67 class GrowableElement : public CHeapObj {
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 };
76 class GrowableCache VALUE_OBJ_CLASS_SPEC {
78 private:
79 // Object pointer passed into cache & listener functions.
80 void *_this_obj;
82 // Array of elements in the collection
83 GrowableArray<GrowableElement *> *_elements;
85 // Parallel array of cached values
86 address *_cache;
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*);
93 static bool equals(void *, GrowableElement *);
95 // recache all elements after size change, notify listener
96 void recache();
98 public:
99 GrowableCache();
100 ~GrowableCache();
102 void initialize(void *this_obj, void listener_fun(void *, address*) );
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 };
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 //
133 class JvmtiBreakpointCache : public CHeapObj {
135 private:
136 GrowableCache _cache;
138 public:
139 JvmtiBreakpointCache() {}
140 ~JvmtiBreakpointCache() {}
142 void initialize(void *this_obj, void listener_fun(void *, address*) ) {
143 _cache.initialize(this_obj,listener_fun);
144 }
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 };
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 //
167 typedef void (methodOopDesc::*method_action)(int _bci);
169 class JvmtiBreakpoint : public GrowableElement {
170 private:
171 methodOop _method;
172 int _bci;
173 Bytecodes::Code _orig_bytecode;
175 public:
176 JvmtiBreakpoint();
177 JvmtiBreakpoint(methodOop m_method, jlocation location);
178 bool equals(JvmtiBreakpoint& bp);
179 bool lessThan(JvmtiBreakpoint &bp);
180 void copy(JvmtiBreakpoint& bp);
181 bool is_valid();
182 address getBcp();
183 void each_method_version_do(method_action meth_act);
184 void set();
185 void clear();
186 void print();
188 methodOop method() { return _method; }
190 // GrowableElement implementation
191 address getCacheValue() { return getBcp(); }
192 bool lessThan(GrowableElement* e) { Unimplemented(); return false; }
193 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); }
194 void oops_do(OopClosure* f) { f->do_oop((oop *) &_method); }
195 GrowableElement *clone() {
196 JvmtiBreakpoint *bp = new JvmtiBreakpoint();
197 bp->copy(*this);
198 return bp;
199 }
200 };
203 ///////////////////////////////////////////////////////////////
204 //
205 // class VM_ChangeBreakpoints
206 // Used by : JvmtiBreakpoints
207 // Used by JVMTI methods: none directly.
208 // Note: A Helper class.
209 //
210 // VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class.
211 //
213 class VM_ChangeBreakpoints : public VM_Operation {
214 private:
215 JvmtiBreakpoints* _breakpoints;
216 int _operation;
217 JvmtiBreakpoint* _bp;
219 public:
220 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1, CLEAR_ALL_BREAKPOINT=2 };
222 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation) {
223 _breakpoints = breakpoints;
224 _bp = NULL;
225 _operation = operation;
226 assert(breakpoints != NULL, "breakpoints != NULL");
227 assert(operation == CLEAR_ALL_BREAKPOINT, "unknown breakpoint operation");
228 }
229 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation, JvmtiBreakpoint *bp) {
230 _breakpoints = breakpoints;
231 _bp = bp;
232 _operation = operation;
233 assert(breakpoints != NULL, "breakpoints != NULL");
234 assert(bp != NULL, "bp != NULL");
235 assert(operation == SET_BREAKPOINT || operation == CLEAR_BREAKPOINT , "unknown breakpoint operation");
236 }
238 VMOp_Type type() const { return VMOp_ChangeBreakpoints; }
239 void doit();
240 void oops_do(OopClosure* f);
241 };
244 ///////////////////////////////////////////////////////////////
245 //
246 // class JvmtiBreakpoints
247 // Used by : JvmtiCurrentBreakpoints
248 // Used by JVMTI methods: none directly
249 // Note: A Helper class
250 //
251 // JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint.
252 // All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints.
253 //
254 // Because _bps is only modified at safepoints, its possible to always use the
255 // cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints).
256 //
257 // It would be possible to make JvmtiBreakpoints a static class, but I've made it
258 // CHeap allocated to emphasize its similarity to JvmtiFramePops.
259 //
261 class JvmtiBreakpoints : public CHeapObj {
262 private:
264 JvmtiBreakpointCache _bps;
266 // These should only be used by VM_ChangeBreakpoints
267 // to insure they only occur at safepoints.
268 // Todo: add checks for safepoint
269 friend class VM_ChangeBreakpoints;
270 void set_at_safepoint(JvmtiBreakpoint& bp);
271 void clear_at_safepoint(JvmtiBreakpoint& bp);
272 void clearall_at_safepoint();
274 static void do_element(GrowableElement *e);
276 public:
277 JvmtiBreakpoints(void listener_fun(void *, address *));
278 ~JvmtiBreakpoints();
280 int length();
281 void oops_do(OopClosure* f);
282 void print();
284 int set(JvmtiBreakpoint& bp);
285 int clear(JvmtiBreakpoint& bp);
286 void clearall_in_class_at_safepoint(klassOop klass);
287 void clearall();
288 void gc_epilogue();
289 };
292 ///////////////////////////////////////////////////////////////
293 //
294 // class JvmtiCurrentBreakpoints
295 //
296 // A static wrapper class for the JvmtiBreakpoints that provides:
297 // 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint).
298 // 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary,
299 // but I'm copying the code from JvmtiThreadState which needs to lazily initialize
300 // JvmtiFramePops).
301 // 3. An oops_do entry point for GC'ing the breakpoint array.
302 //
304 class JvmtiCurrentBreakpoints : public AllStatic {
306 private:
308 // Current breakpoints, lazily initialized by get_jvmti_breakpoints();
309 static JvmtiBreakpoints *_jvmti_breakpoints;
311 // NULL terminated cache of byte-code pointers corresponding to current breakpoints.
312 // Updated only at safepoints (with listener_fun) when the cache is moved.
313 // It exists only to make is_breakpoint fast.
314 static address *_breakpoint_list;
315 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; }
316 static inline address *get_breakpoint_list() { return _breakpoint_list; }
318 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list.
319 static void listener_fun(void *this_obj, address *cache);
321 public:
322 static void initialize();
323 static void destroy();
325 // lazily create _jvmti_breakpoints and _breakpoint_list
326 static JvmtiBreakpoints& get_jvmti_breakpoints();
328 // quickly test whether the bcp matches a cached breakpoint in the list
329 static inline bool is_breakpoint(address bcp);
331 static void oops_do(OopClosure* f);
332 static void gc_epilogue();
333 };
335 // quickly test whether the bcp matches a cached breakpoint in the list
336 bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) {
337 address *bps = get_breakpoint_list();
338 if (bps == NULL) return false;
339 for ( ; (*bps) != NULL; bps++) {
340 if ((*bps) == bcp) return true;
341 }
342 return false;
343 }
345 ///////////////////////////////////////////////////////////////
346 // The get/set local operations must only be done by the VM thread
347 // because the interpreter version needs to access oop maps, which can
348 // only safely be done by the VM thread
349 //
350 // I'm told that in 1.5 oop maps are now protected by a lock and
351 // we could get rid of the VM op
352 // However if the VM op is removed then the target thread must
353 // be suspended AND a lock will be needed to prevent concurrent
354 // setting of locals to the same java thread. This lock is needed
355 // to prevent compiledVFrames from trying to add deferred updates
356 // to the thread simultaneously.
357 //
358 class VM_GetOrSetLocal : public VM_Operation {
359 protected:
360 JavaThread* _thread;
361 JavaThread* _calling_thread;
362 jint _depth;
363 jint _index;
364 BasicType _type;
365 jvalue _value;
366 javaVFrame* _jvf;
367 bool _set;
369 // It is possible to get the receiver out of a non-static native wrapper
370 // frame. Use VM_GetReceiver to do this.
371 virtual bool getting_receiver() const { return false; }
373 jvmtiError _result;
375 vframe* get_vframe();
376 javaVFrame* get_java_vframe();
377 bool check_slot_type(javaVFrame* vf);
379 public:
380 // Constructor for non-object getter
381 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type);
383 // Constructor for object or non-object setter
384 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value);
386 // Constructor for object getter
387 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth,
388 int index);
390 VMOp_Type type() const { return VMOp_GetOrSetLocal; }
391 jvalue value() { return _value; }
392 jvmtiError result() { return _result; }
394 bool doit_prologue();
395 void doit();
396 bool allow_nested_vm_operations() const;
397 const char* name() const { return "get/set locals"; }
399 // Check that the klass is assignable to a type with the given signature.
400 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread);
401 };
403 class VM_GetReceiver : public VM_GetOrSetLocal {
404 protected:
405 virtual bool getting_receiver() const { return true; }
407 public:
408 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth);
409 const char* name() const { return "get receiver"; }
410 };
413 ///////////////////////////////////////////////////////////////
414 //
415 // class JvmtiSuspendControl
416 //
417 // Convenience routines for suspending and resuming threads.
418 //
419 // All attempts by JVMTI to suspend and resume threads must go through the
420 // JvmtiSuspendControl interface.
421 //
422 // methods return true if successful
423 //
424 class JvmtiSuspendControl : public AllStatic {
425 public:
426 // suspend the thread, taking it to a safepoint
427 static bool suspend(JavaThread *java_thread);
428 // resume the thread
429 static bool resume(JavaThread *java_thread);
431 static void print();
432 };
434 #endif // !JVMTI_KERNEL
436 // Utility macro that checks for NULL pointers:
437 #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); }
439 #endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP