src/share/vm/prims/jvmtiImpl.cpp

Mon, 21 Oct 2013 14:20:47 +0200

author
ehelin
date
Mon, 21 Oct 2013 14:20:47 +0200
changeset 6008
2fab5b7e6140
parent 5749
4f9a42c33738
child 6063
910026b800b8
permissions
-rw-r--r--

8025834: NPE in Parallel Scavenge with -XX:+CheckUnhandledOops
Reviewed-by: coleenp, mgerdin, sspitsyn

duke@435 1 /*
zgu@4492 2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/systemDictionary.hpp"
stefank@2314 27 #include "interpreter/interpreter.hpp"
stefank@2314 28 #include "jvmtifiles/jvmtiEnv.hpp"
stefank@2314 29 #include "memory/resourceArea.hpp"
stefank@2314 30 #include "oops/instanceKlass.hpp"
stefank@2314 31 #include "prims/jvmtiAgentThread.hpp"
stefank@2314 32 #include "prims/jvmtiEventController.inline.hpp"
stefank@2314 33 #include "prims/jvmtiImpl.hpp"
stefank@2314 34 #include "prims/jvmtiRedefineClasses.hpp"
kamg@2511 35 #include "runtime/atomic.hpp"
stefank@2314 36 #include "runtime/deoptimization.hpp"
stefank@2314 37 #include "runtime/handles.hpp"
stefank@2314 38 #include "runtime/handles.inline.hpp"
stefank@2314 39 #include "runtime/interfaceSupport.hpp"
stefank@2314 40 #include "runtime/javaCalls.hpp"
dcubed@2836 41 #include "runtime/os.hpp"
kamg@2511 42 #include "runtime/serviceThread.hpp"
stefank@2314 43 #include "runtime/signature.hpp"
stefank@4299 44 #include "runtime/thread.inline.hpp"
stefank@2314 45 #include "runtime/vframe.hpp"
stefank@2314 46 #include "runtime/vframe_hp.hpp"
stefank@2314 47 #include "runtime/vm_operations.hpp"
stefank@2314 48 #include "utilities/exceptions.hpp"
duke@435 49
duke@435 50 //
duke@435 51 // class JvmtiAgentThread
duke@435 52 //
duke@435 53 // JavaThread used to wrap a thread started by an agent
duke@435 54 // using the JVMTI method RunAgentThread.
duke@435 55 //
duke@435 56
duke@435 57 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
duke@435 58 : JavaThread(start_function_wrapper) {
duke@435 59 _env = env;
duke@435 60 _start_fn = start_fn;
duke@435 61 _start_arg = start_arg;
duke@435 62 }
duke@435 63
duke@435 64 void
duke@435 65 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
duke@435 66 // It is expected that any Agent threads will be created as
duke@435 67 // Java Threads. If this is the case, notification of the creation
duke@435 68 // of the thread is given in JavaThread::thread_main().
duke@435 69 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
duke@435 70 assert(thread == JavaThread::current(), "sanity check");
duke@435 71
duke@435 72 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
duke@435 73 dthread->call_start_function();
duke@435 74 }
duke@435 75
duke@435 76 void
duke@435 77 JvmtiAgentThread::call_start_function() {
duke@435 78 ThreadToNativeFromVM transition(this);
duke@435 79 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
duke@435 80 }
duke@435 81
duke@435 82
duke@435 83 //
duke@435 84 // class GrowableCache - private methods
duke@435 85 //
duke@435 86
duke@435 87 void GrowableCache::recache() {
duke@435 88 int len = _elements->length();
duke@435 89
zgu@3900 90 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
zgu@3900 91 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
duke@435 92
duke@435 93 for (int i=0; i<len; i++) {
duke@435 94 _cache[i] = _elements->at(i)->getCacheValue();
duke@435 95 //
duke@435 96 // The cache entry has gone bad. Without a valid frame pointer
duke@435 97 // value, the entry is useless so we simply delete it in product
duke@435 98 // mode. The call to remove() will rebuild the cache again
duke@435 99 // without the bad entry.
duke@435 100 //
duke@435 101 if (_cache[i] == NULL) {
duke@435 102 assert(false, "cannot recache NULL elements");
duke@435 103 remove(i);
duke@435 104 return;
duke@435 105 }
duke@435 106 }
duke@435 107 _cache[len] = NULL;
duke@435 108
duke@435 109 _listener_fun(_this_obj,_cache);
duke@435 110 }
duke@435 111
duke@435 112 bool GrowableCache::equals(void* v, GrowableElement *e2) {
duke@435 113 GrowableElement *e1 = (GrowableElement *) v;
duke@435 114 assert(e1 != NULL, "e1 != NULL");
duke@435 115 assert(e2 != NULL, "e2 != NULL");
duke@435 116
duke@435 117 return e1->equals(e2);
duke@435 118 }
duke@435 119
duke@435 120 //
duke@435 121 // class GrowableCache - public methods
duke@435 122 //
duke@435 123
duke@435 124 GrowableCache::GrowableCache() {
duke@435 125 _this_obj = NULL;
duke@435 126 _listener_fun = NULL;
duke@435 127 _elements = NULL;
duke@435 128 _cache = NULL;
duke@435 129 }
duke@435 130
duke@435 131 GrowableCache::~GrowableCache() {
duke@435 132 clear();
duke@435 133 delete _elements;
zgu@3900 134 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
duke@435 135 }
duke@435 136
duke@435 137 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
duke@435 138 _this_obj = this_obj;
duke@435 139 _listener_fun = listener_fun;
zgu@3900 140 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
duke@435 141 recache();
duke@435 142 }
duke@435 143
duke@435 144 // number of elements in the collection
duke@435 145 int GrowableCache::length() {
duke@435 146 return _elements->length();
duke@435 147 }
duke@435 148
duke@435 149 // get the value of the index element in the collection
duke@435 150 GrowableElement* GrowableCache::at(int index) {
duke@435 151 GrowableElement *e = (GrowableElement *) _elements->at(index);
duke@435 152 assert(e != NULL, "e != NULL");
duke@435 153 return e;
duke@435 154 }
duke@435 155
duke@435 156 int GrowableCache::find(GrowableElement* e) {
duke@435 157 return _elements->find(e, GrowableCache::equals);
duke@435 158 }
duke@435 159
duke@435 160 // append a copy of the element to the end of the collection
duke@435 161 void GrowableCache::append(GrowableElement* e) {
duke@435 162 GrowableElement *new_e = e->clone();
duke@435 163 _elements->append(new_e);
duke@435 164 recache();
duke@435 165 }
duke@435 166
duke@435 167 // insert a copy of the element using lessthan()
duke@435 168 void GrowableCache::insert(GrowableElement* e) {
duke@435 169 GrowableElement *new_e = e->clone();
duke@435 170 _elements->append(new_e);
duke@435 171
duke@435 172 int n = length()-2;
duke@435 173 for (int i=n; i>=0; i--) {
duke@435 174 GrowableElement *e1 = _elements->at(i);
duke@435 175 GrowableElement *e2 = _elements->at(i+1);
duke@435 176 if (e2->lessThan(e1)) {
duke@435 177 _elements->at_put(i+1, e1);
duke@435 178 _elements->at_put(i, e2);
duke@435 179 }
duke@435 180 }
duke@435 181
duke@435 182 recache();
duke@435 183 }
duke@435 184
duke@435 185 // remove the element at index
duke@435 186 void GrowableCache::remove (int index) {
duke@435 187 GrowableElement *e = _elements->at(index);
duke@435 188 assert(e != NULL, "e != NULL");
duke@435 189 _elements->remove(e);
duke@435 190 delete e;
duke@435 191 recache();
duke@435 192 }
duke@435 193
duke@435 194 // clear out all elements, release all heap space and
duke@435 195 // let our listener know that things have changed.
duke@435 196 void GrowableCache::clear() {
duke@435 197 int len = _elements->length();
duke@435 198 for (int i=0; i<len; i++) {
duke@435 199 delete _elements->at(i);
duke@435 200 }
duke@435 201 _elements->clear();
duke@435 202 recache();
duke@435 203 }
duke@435 204
duke@435 205 void GrowableCache::oops_do(OopClosure* f) {
duke@435 206 int len = _elements->length();
duke@435 207 for (int i=0; i<len; i++) {
duke@435 208 GrowableElement *e = _elements->at(i);
duke@435 209 e->oops_do(f);
kamg@2467 210 }
kamg@2467 211 }
kamg@2467 212
kamg@2467 213 void GrowableCache::gc_epilogue() {
kamg@2467 214 int len = _elements->length();
kamg@2467 215 for (int i=0; i<len; i++) {
kamg@2467 216 _cache[i] = _elements->at(i)->getCacheValue();
duke@435 217 }
duke@435 218 }
duke@435 219
duke@435 220 //
duke@435 221 // class JvmtiBreakpoint
duke@435 222 //
duke@435 223
duke@435 224 JvmtiBreakpoint::JvmtiBreakpoint() {
duke@435 225 _method = NULL;
duke@435 226 _bci = 0;
coleenp@4037 227 _class_loader = NULL;
duke@435 228 }
duke@435 229
coleenp@4037 230 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
duke@435 231 _method = m_method;
coleenp@4037 232 _class_loader = _method->method_holder()->class_loader_data()->class_loader();
ehelin@6008 233 #ifdef CHECK_UNHANDLED_OOPS
ehelin@6008 234 // _class_loader can't be wrapped in a Handle, because JvmtiBreakpoint:s are
ehelin@6008 235 // eventually allocated on the heap.
ehelin@6008 236 //
ehelin@6008 237 // The code handling JvmtiBreakpoint:s allocated on the stack can't be
ehelin@6008 238 // interrupted by a GC until _class_loader is reachable by the GC via the
ehelin@6008 239 // oops_do method.
ehelin@6008 240 Thread::current()->allow_unhandled_oop(&_class_loader);
ehelin@6008 241 #endif // CHECK_UNHANDLED_OOPS
duke@435 242 assert(_method != NULL, "_method != NULL");
duke@435 243 _bci = (int) location;
duke@435 244 assert(_bci >= 0, "_bci >= 0");
duke@435 245 }
duke@435 246
duke@435 247 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
duke@435 248 _method = bp._method;
duke@435 249 _bci = bp._bci;
coleenp@4037 250 _class_loader = bp._class_loader;
duke@435 251 }
duke@435 252
duke@435 253 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
duke@435 254 Unimplemented();
duke@435 255 return false;
duke@435 256 }
duke@435 257
duke@435 258 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
duke@435 259 return _method == bp._method
duke@435 260 && _bci == bp._bci;
duke@435 261 }
duke@435 262
duke@435 263 bool JvmtiBreakpoint::is_valid() {
coleenp@4037 264 // class loader can be NULL
duke@435 265 return _method != NULL &&
duke@435 266 _bci >= 0;
duke@435 267 }
duke@435 268
duke@435 269 address JvmtiBreakpoint::getBcp() {
duke@435 270 return _method->bcp_from(_bci);
duke@435 271 }
duke@435 272
duke@435 273 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
coleenp@4037 274 ((Method*)_method->*meth_act)(_bci);
duke@435 275
duke@435 276 // add/remove breakpoint to/from versions of the method that
duke@435 277 // are EMCP. Directly or transitively obsolete methods are
coleenp@5749 278 // not saved in the PreviousVersionNodes.
duke@435 279 Thread *thread = Thread::current();
duke@435 280 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
coleenp@2497 281 Symbol* m_name = _method->name();
coleenp@2497 282 Symbol* m_signature = _method->signature();
duke@435 283
coleenp@5749 284 // search previous versions if they exist
coleenp@5749 285 PreviousVersionWalker pvw(thread, (InstanceKlass *)ikh());
coleenp@5749 286 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
coleenp@5749 287 pv_node != NULL; pv_node = pvw.next_previous_version()) {
coleenp@5749 288 GrowableArray<Method*>* methods = pv_node->prev_EMCP_methods();
duke@435 289
coleenp@5749 290 if (methods == NULL) {
coleenp@5749 291 // We have run into a PreviousVersion generation where
coleenp@5749 292 // all methods were made obsolete during that generation's
coleenp@5749 293 // RedefineClasses() operation. At the time of that
coleenp@5749 294 // operation, all EMCP methods were flushed so we don't
coleenp@5749 295 // have to go back any further.
coleenp@5749 296 //
coleenp@5749 297 // A NULL methods array is different than an empty methods
coleenp@5749 298 // array. We cannot infer any optimizations about older
coleenp@5749 299 // generations from an empty methods array for the current
coleenp@5749 300 // generation.
coleenp@5749 301 break;
coleenp@5749 302 }
duke@435 303
coleenp@5749 304 for (int i = methods->length() - 1; i >= 0; i--) {
coleenp@5749 305 Method* method = methods->at(i);
coleenp@5749 306 // obsolete methods that are running are not deleted from
coleenp@5749 307 // previous version array, but they are skipped here.
coleenp@5749 308 if (!method->is_obsolete() &&
coleenp@5749 309 method->name() == m_name &&
coleenp@5749 310 method->signature() == m_signature) {
coleenp@5749 311 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
coleenp@5749 312 meth_act == &Method::set_breakpoint ? "sett" : "clear",
coleenp@5749 313 method->name()->as_C_string(),
coleenp@5749 314 method->signature()->as_C_string()));
duke@435 315
coleenp@5749 316 (method->*meth_act)(_bci);
coleenp@5749 317 break;
duke@435 318 }
coleenp@5749 319 }
coleenp@5749 320 }
duke@435 321 }
duke@435 322
duke@435 323 void JvmtiBreakpoint::set() {
coleenp@4037 324 each_method_version_do(&Method::set_breakpoint);
duke@435 325 }
duke@435 326
duke@435 327 void JvmtiBreakpoint::clear() {
coleenp@4037 328 each_method_version_do(&Method::clear_breakpoint);
duke@435 329 }
duke@435 330
duke@435 331 void JvmtiBreakpoint::print() {
duke@435 332 #ifndef PRODUCT
duke@435 333 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
duke@435 334 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
duke@435 335
duke@435 336 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
duke@435 337 #endif
duke@435 338 }
duke@435 339
duke@435 340
duke@435 341 //
duke@435 342 // class VM_ChangeBreakpoints
duke@435 343 //
duke@435 344 // Modify the Breakpoints data structure at a safepoint
duke@435 345 //
duke@435 346
duke@435 347 void VM_ChangeBreakpoints::doit() {
duke@435 348 switch (_operation) {
duke@435 349 case SET_BREAKPOINT:
duke@435 350 _breakpoints->set_at_safepoint(*_bp);
duke@435 351 break;
duke@435 352 case CLEAR_BREAKPOINT:
duke@435 353 _breakpoints->clear_at_safepoint(*_bp);
duke@435 354 break;
duke@435 355 default:
duke@435 356 assert(false, "Unknown operation");
duke@435 357 }
duke@435 358 }
duke@435 359
duke@435 360 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
sla@5237 361 // The JvmtiBreakpoints in _breakpoints will be visited via
sla@5237 362 // JvmtiExport::oops_do.
duke@435 363 if (_bp != NULL) {
duke@435 364 _bp->oops_do(f);
duke@435 365 }
duke@435 366 }
duke@435 367
duke@435 368 //
duke@435 369 // class JvmtiBreakpoints
duke@435 370 //
duke@435 371 // a JVMTI internal collection of JvmtiBreakpoint
duke@435 372 //
duke@435 373
duke@435 374 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
duke@435 375 _bps.initialize(this,listener_fun);
duke@435 376 }
duke@435 377
duke@435 378 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
duke@435 379
duke@435 380 void JvmtiBreakpoints::oops_do(OopClosure* f) {
duke@435 381 _bps.oops_do(f);
duke@435 382 }
duke@435 383
kamg@2467 384 void JvmtiBreakpoints::gc_epilogue() {
kamg@2467 385 _bps.gc_epilogue();
kamg@2467 386 }
kamg@2467 387
duke@435 388 void JvmtiBreakpoints::print() {
duke@435 389 #ifndef PRODUCT
duke@435 390 ResourceMark rm;
duke@435 391
duke@435 392 int n = _bps.length();
duke@435 393 for (int i=0; i<n; i++) {
duke@435 394 JvmtiBreakpoint& bp = _bps.at(i);
duke@435 395 tty->print("%d: ", i);
duke@435 396 bp.print();
duke@435 397 tty->print_cr("");
duke@435 398 }
duke@435 399 #endif
duke@435 400 }
duke@435 401
duke@435 402
duke@435 403 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
duke@435 404 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
duke@435 405
duke@435 406 int i = _bps.find(bp);
duke@435 407 if (i == -1) {
duke@435 408 _bps.append(bp);
duke@435 409 bp.set();
duke@435 410 }
duke@435 411 }
duke@435 412
duke@435 413 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
duke@435 414 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
duke@435 415
duke@435 416 int i = _bps.find(bp);
duke@435 417 if (i != -1) {
duke@435 418 _bps.remove(i);
duke@435 419 bp.clear();
duke@435 420 }
duke@435 421 }
duke@435 422
duke@435 423 int JvmtiBreakpoints::length() { return _bps.length(); }
duke@435 424
duke@435 425 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
duke@435 426 if ( _bps.find(bp) != -1) {
duke@435 427 return JVMTI_ERROR_DUPLICATE;
duke@435 428 }
sla@5237 429 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
duke@435 430 VMThread::execute(&set_breakpoint);
duke@435 431 return JVMTI_ERROR_NONE;
duke@435 432 }
duke@435 433
duke@435 434 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
duke@435 435 if ( _bps.find(bp) == -1) {
duke@435 436 return JVMTI_ERROR_NOT_FOUND;
duke@435 437 }
duke@435 438
sla@5237 439 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
duke@435 440 VMThread::execute(&clear_breakpoint);
duke@435 441 return JVMTI_ERROR_NONE;
duke@435 442 }
duke@435 443
coleenp@4037 444 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
duke@435 445 bool changed = true;
duke@435 446 // We are going to run thru the list of bkpts
duke@435 447 // and delete some. This deletion probably alters
duke@435 448 // the list in some implementation defined way such
duke@435 449 // that when we delete entry i, the next entry might
duke@435 450 // no longer be at i+1. To be safe, each time we delete
duke@435 451 // an entry, we'll just start again from the beginning.
duke@435 452 // We'll stop when we make a pass thru the whole list without
duke@435 453 // deleting anything.
duke@435 454 while (changed) {
duke@435 455 int len = _bps.length();
duke@435 456 changed = false;
duke@435 457 for (int i = 0; i < len; i++) {
duke@435 458 JvmtiBreakpoint& bp = _bps.at(i);
duke@435 459 if (bp.method()->method_holder() == klass) {
duke@435 460 bp.clear();
duke@435 461 _bps.remove(i);
duke@435 462 // This changed 'i' so we have to start over.
duke@435 463 changed = true;
duke@435 464 break;
duke@435 465 }
duke@435 466 }
duke@435 467 }
duke@435 468 }
duke@435 469
duke@435 470 //
duke@435 471 // class JvmtiCurrentBreakpoints
duke@435 472 //
duke@435 473
duke@435 474 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
duke@435 475 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
duke@435 476
duke@435 477
duke@435 478 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
duke@435 479 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
duke@435 480 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
duke@435 481 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
duke@435 482 return (*_jvmti_breakpoints);
duke@435 483 }
duke@435 484
duke@435 485 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
duke@435 486 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
duke@435 487 assert(this_jvmti != NULL, "this_jvmti != NULL");
duke@435 488
duke@435 489 debug_only(int n = this_jvmti->length(););
duke@435 490 assert(cache[n] == NULL, "cache must be NULL terminated");
duke@435 491
duke@435 492 set_breakpoint_list(cache);
duke@435 493 }
duke@435 494
duke@435 495
duke@435 496 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
duke@435 497 if (_jvmti_breakpoints != NULL) {
duke@435 498 _jvmti_breakpoints->oops_do(f);
duke@435 499 }
duke@435 500 }
duke@435 501
kamg@2467 502 void JvmtiCurrentBreakpoints::gc_epilogue() {
kamg@2467 503 if (_jvmti_breakpoints != NULL) {
kamg@2467 504 _jvmti_breakpoints->gc_epilogue();
kamg@2467 505 }
kamg@2467 506 }
kamg@2467 507
duke@435 508 ///////////////////////////////////////////////////////////////
duke@435 509 //
duke@435 510 // class VM_GetOrSetLocal
duke@435 511 //
duke@435 512
duke@435 513 // Constructor for non-object getter
duke@435 514 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
duke@435 515 : _thread(thread)
duke@435 516 , _calling_thread(NULL)
duke@435 517 , _depth(depth)
duke@435 518 , _index(index)
duke@435 519 , _type(type)
duke@435 520 , _set(false)
duke@435 521 , _jvf(NULL)
duke@435 522 , _result(JVMTI_ERROR_NONE)
duke@435 523 {
duke@435 524 }
duke@435 525
duke@435 526 // Constructor for object or non-object setter
duke@435 527 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
duke@435 528 : _thread(thread)
duke@435 529 , _calling_thread(NULL)
duke@435 530 , _depth(depth)
duke@435 531 , _index(index)
duke@435 532 , _type(type)
duke@435 533 , _value(value)
duke@435 534 , _set(true)
duke@435 535 , _jvf(NULL)
duke@435 536 , _result(JVMTI_ERROR_NONE)
duke@435 537 {
duke@435 538 }
duke@435 539
duke@435 540 // Constructor for object getter
duke@435 541 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
duke@435 542 : _thread(thread)
duke@435 543 , _calling_thread(calling_thread)
duke@435 544 , _depth(depth)
duke@435 545 , _index(index)
duke@435 546 , _type(T_OBJECT)
duke@435 547 , _set(false)
duke@435 548 , _jvf(NULL)
duke@435 549 , _result(JVMTI_ERROR_NONE)
duke@435 550 {
duke@435 551 }
duke@435 552
duke@435 553 vframe *VM_GetOrSetLocal::get_vframe() {
duke@435 554 if (!_thread->has_last_Java_frame()) {
duke@435 555 return NULL;
duke@435 556 }
duke@435 557 RegisterMap reg_map(_thread);
duke@435 558 vframe *vf = _thread->last_java_vframe(&reg_map);
duke@435 559 int d = 0;
duke@435 560 while ((vf != NULL) && (d < _depth)) {
duke@435 561 vf = vf->java_sender();
duke@435 562 d++;
duke@435 563 }
duke@435 564 return vf;
duke@435 565 }
duke@435 566
duke@435 567 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
duke@435 568 vframe* vf = get_vframe();
duke@435 569 if (vf == NULL) {
duke@435 570 _result = JVMTI_ERROR_NO_MORE_FRAMES;
duke@435 571 return NULL;
duke@435 572 }
duke@435 573 javaVFrame *jvf = (javaVFrame*)vf;
duke@435 574
kamg@2361 575 if (!vf->is_java_frame()) {
duke@435 576 _result = JVMTI_ERROR_OPAQUE_FRAME;
duke@435 577 return NULL;
duke@435 578 }
duke@435 579 return jvf;
duke@435 580 }
duke@435 581
duke@435 582 // Check that the klass is assignable to a type with the given signature.
duke@435 583 // Another solution could be to use the function Klass::is_subtype_of(type).
duke@435 584 // But the type class can be forced to load/initialize eagerly in such a case.
duke@435 585 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
duke@435 586 // It is better to avoid such a behavior.
duke@435 587 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
duke@435 588 assert(ty_sign != NULL, "type signature must not be NULL");
duke@435 589 assert(thread != NULL, "thread must not be NULL");
duke@435 590 assert(klass != NULL, "klass must not be NULL");
duke@435 591
duke@435 592 int len = (int) strlen(ty_sign);
duke@435 593 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
duke@435 594 ty_sign++;
duke@435 595 len -= 2;
duke@435 596 }
coleenp@2497 597 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
coleenp@2497 598 if (klass->name() == ty_sym) {
duke@435 599 return true;
duke@435 600 }
duke@435 601 // Compare primary supers
duke@435 602 int super_depth = klass->super_depth();
duke@435 603 int idx;
duke@435 604 for (idx = 0; idx < super_depth; idx++) {
hseigel@4278 605 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
duke@435 606 return true;
duke@435 607 }
duke@435 608 }
duke@435 609 // Compare secondary supers
coleenp@4037 610 Array<Klass*>* sec_supers = klass->secondary_supers();
duke@435 611 for (idx = 0; idx < sec_supers->length(); idx++) {
hseigel@4278 612 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
duke@435 613 return true;
duke@435 614 }
duke@435 615 }
duke@435 616 return false;
duke@435 617 }
duke@435 618
duke@435 619 // Checks error conditions:
duke@435 620 // JVMTI_ERROR_INVALID_SLOT
duke@435 621 // JVMTI_ERROR_TYPE_MISMATCH
duke@435 622 // Returns: 'true' - everything is Ok, 'false' - error code
duke@435 623
duke@435 624 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
coleenp@4037 625 Method* method_oop = jvf->method();
duke@435 626 if (!method_oop->has_localvariable_table()) {
duke@435 627 // Just to check index boundaries
duke@435 628 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
duke@435 629 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
duke@435 630 _result = JVMTI_ERROR_INVALID_SLOT;
duke@435 631 return false;
duke@435 632 }
duke@435 633 return true;
duke@435 634 }
duke@435 635
duke@435 636 jint num_entries = method_oop->localvariable_table_length();
duke@435 637 if (num_entries == 0) {
duke@435 638 _result = JVMTI_ERROR_INVALID_SLOT;
duke@435 639 return false; // There are no slots
duke@435 640 }
duke@435 641 int signature_idx = -1;
duke@435 642 int vf_bci = jvf->bci();
duke@435 643 LocalVariableTableElement* table = method_oop->localvariable_table_start();
duke@435 644 for (int i = 0; i < num_entries; i++) {
duke@435 645 int start_bci = table[i].start_bci;
duke@435 646 int end_bci = start_bci + table[i].length;
duke@435 647
duke@435 648 // Here we assume that locations of LVT entries
duke@435 649 // with the same slot number cannot be overlapped
duke@435 650 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
duke@435 651 signature_idx = (int) table[i].descriptor_cp_index;
duke@435 652 break;
duke@435 653 }
duke@435 654 }
duke@435 655 if (signature_idx == -1) {
duke@435 656 _result = JVMTI_ERROR_INVALID_SLOT;
duke@435 657 return false; // Incorrect slot index
duke@435 658 }
coleenp@2497 659 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
duke@435 660 const char* signature = (const char *) sign_sym->as_utf8();
duke@435 661 BasicType slot_type = char2type(signature[0]);
duke@435 662
duke@435 663 switch (slot_type) {
duke@435 664 case T_BYTE:
duke@435 665 case T_SHORT:
duke@435 666 case T_CHAR:
duke@435 667 case T_BOOLEAN:
duke@435 668 slot_type = T_INT;
duke@435 669 break;
duke@435 670 case T_ARRAY:
duke@435 671 slot_type = T_OBJECT;
duke@435 672 break;
duke@435 673 };
duke@435 674 if (_type != slot_type) {
duke@435 675 _result = JVMTI_ERROR_TYPE_MISMATCH;
duke@435 676 return false;
duke@435 677 }
duke@435 678
duke@435 679 jobject jobj = _value.l;
duke@435 680 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
duke@435 681 // Check that the jobject class matches the return type signature.
duke@435 682 JavaThread* cur_thread = JavaThread::current();
duke@435 683 HandleMark hm(cur_thread);
duke@435 684
duke@435 685 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
duke@435 686 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
duke@435 687 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
duke@435 688 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
duke@435 689
hseigel@4278 690 if (!is_assignable(signature, ob_kh(), cur_thread)) {
duke@435 691 _result = JVMTI_ERROR_TYPE_MISMATCH;
duke@435 692 return false;
duke@435 693 }
duke@435 694 }
duke@435 695 return true;
duke@435 696 }
duke@435 697
duke@435 698 static bool can_be_deoptimized(vframe* vf) {
duke@435 699 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
duke@435 700 }
duke@435 701
duke@435 702 bool VM_GetOrSetLocal::doit_prologue() {
duke@435 703 _jvf = get_java_vframe();
duke@435 704 NULL_CHECK(_jvf, false);
duke@435 705
kamg@2361 706 if (_jvf->method()->is_native()) {
kamg@2361 707 if (getting_receiver() && !_jvf->method()->is_static()) {
kamg@2361 708 return true;
kamg@2361 709 } else {
kamg@2361 710 _result = JVMTI_ERROR_OPAQUE_FRAME;
kamg@2361 711 return false;
kamg@2361 712 }
kamg@2361 713 }
kamg@2361 714
duke@435 715 if (!check_slot_type(_jvf)) {
duke@435 716 return false;
duke@435 717 }
duke@435 718 return true;
duke@435 719 }
duke@435 720
duke@435 721 void VM_GetOrSetLocal::doit() {
duke@435 722 if (_set) {
duke@435 723 // Force deoptimization of frame if compiled because it's
duke@435 724 // possible the compiler emitted some locals as constant values,
duke@435 725 // meaning they are not mutable.
duke@435 726 if (can_be_deoptimized(_jvf)) {
duke@435 727
duke@435 728 // Schedule deoptimization so that eventually the local
duke@435 729 // update will be written to an interpreter frame.
never@2260 730 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
duke@435 731
duke@435 732 // Now store a new value for the local which will be applied
duke@435 733 // once deoptimization occurs. Note however that while this
duke@435 734 // write is deferred until deoptimization actually happens
duke@435 735 // can vframe created after this point will have its locals
duke@435 736 // reflecting this update so as far as anyone can see the
duke@435 737 // write has already taken place.
duke@435 738
duke@435 739 // If we are updating an oop then get the oop from the handle
duke@435 740 // since the handle will be long gone by the time the deopt
duke@435 741 // happens. The oop stored in the deferred local will be
duke@435 742 // gc'd on its own.
duke@435 743 if (_type == T_OBJECT) {
duke@435 744 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
duke@435 745 }
duke@435 746 // Re-read the vframe so we can see that it is deoptimized
duke@435 747 // [ Only need because of assert in update_local() ]
duke@435 748 _jvf = get_java_vframe();
duke@435 749 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
duke@435 750 return;
duke@435 751 }
duke@435 752 StackValueCollection *locals = _jvf->locals();
duke@435 753 HandleMark hm;
duke@435 754
duke@435 755 switch (_type) {
kamg@2361 756 case T_INT: locals->set_int_at (_index, _value.i); break;
kamg@2361 757 case T_LONG: locals->set_long_at (_index, _value.j); break;
kamg@2361 758 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
kamg@2361 759 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
kamg@2361 760 case T_OBJECT: {
kamg@2361 761 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
kamg@2361 762 locals->set_obj_at (_index, ob_h);
kamg@2361 763 break;
kamg@2361 764 }
kamg@2361 765 default: ShouldNotReachHere();
duke@435 766 }
duke@435 767 _jvf->set_locals(locals);
duke@435 768 } else {
kamg@2361 769 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
kamg@2361 770 assert(getting_receiver(), "Can only get here when getting receiver");
kamg@2361 771 oop receiver = _jvf->fr().get_native_receiver();
kamg@2361 772 _value.l = JNIHandles::make_local(_calling_thread, receiver);
kamg@2361 773 } else {
kamg@2361 774 StackValueCollection *locals = _jvf->locals();
duke@435 775
kamg@2361 776 if (locals->at(_index)->type() == T_CONFLICT) {
kamg@2361 777 memset(&_value, 0, sizeof(_value));
kamg@2361 778 _value.l = NULL;
kamg@2361 779 return;
kamg@2361 780 }
duke@435 781
kamg@2361 782 switch (_type) {
kamg@2361 783 case T_INT: _value.i = locals->int_at (_index); break;
kamg@2361 784 case T_LONG: _value.j = locals->long_at (_index); break;
kamg@2361 785 case T_FLOAT: _value.f = locals->float_at (_index); break;
kamg@2361 786 case T_DOUBLE: _value.d = locals->double_at(_index); break;
kamg@2361 787 case T_OBJECT: {
kamg@2361 788 // Wrap the oop to be returned in a local JNI handle since
kamg@2361 789 // oops_do() no longer applies after doit() is finished.
kamg@2361 790 oop obj = locals->obj_at(_index)();
kamg@2361 791 _value.l = JNIHandles::make_local(_calling_thread, obj);
kamg@2361 792 break;
kamg@2361 793 }
kamg@2361 794 default: ShouldNotReachHere();
kamg@2361 795 }
duke@435 796 }
duke@435 797 }
duke@435 798 }
duke@435 799
duke@435 800
duke@435 801 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
duke@435 802 return true; // May need to deoptimize
duke@435 803 }
duke@435 804
duke@435 805
kamg@2361 806 VM_GetReceiver::VM_GetReceiver(
kamg@2361 807 JavaThread* thread, JavaThread* caller_thread, jint depth)
kamg@2361 808 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
kamg@2361 809
duke@435 810 /////////////////////////////////////////////////////////////////////////////////////////
duke@435 811
duke@435 812 //
duke@435 813 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
duke@435 814 //
duke@435 815
duke@435 816 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
duke@435 817 // external suspend should have caught suspending a thread twice
duke@435 818
duke@435 819 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
duke@435 820 // not deadlock due to later suspension on transitions while holding
duke@435 821 // raw monitors. Passing true causes the immediate suspension.
duke@435 822 // java_suspend() will catch threads in the process of exiting
duke@435 823 // and will ignore them.
duke@435 824 java_thread->java_suspend();
duke@435 825
duke@435 826 // It would be nice to have the following assertion in all the time,
duke@435 827 // but it is possible for a racing resume request to have resumed
duke@435 828 // this thread right after we suspended it. Temporarily enable this
duke@435 829 // assertion if you are chasing a different kind of bug.
duke@435 830 //
duke@435 831 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
duke@435 832 // java_thread->is_being_ext_suspended(), "thread is not suspended");
duke@435 833
duke@435 834 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
duke@435 835 // check again because we can get delayed in java_suspend():
duke@435 836 // the thread is in process of exiting.
duke@435 837 return false;
duke@435 838 }
duke@435 839
duke@435 840 return true;
duke@435 841 }
duke@435 842
duke@435 843 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
duke@435 844 // external suspend should have caught resuming a thread twice
duke@435 845 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
duke@435 846
duke@435 847 // resume thread
duke@435 848 {
duke@435 849 // must always grab Threads_lock, see JVM_SuspendThread
duke@435 850 MutexLocker ml(Threads_lock);
duke@435 851 java_thread->java_resume();
duke@435 852 }
duke@435 853
duke@435 854 return true;
duke@435 855 }
duke@435 856
duke@435 857
duke@435 858 void JvmtiSuspendControl::print() {
duke@435 859 #ifndef PRODUCT
duke@435 860 MutexLocker mu(Threads_lock);
duke@435 861 ResourceMark rm;
duke@435 862
duke@435 863 tty->print("Suspended Threads: [");
duke@435 864 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
jprovino@4721 865 #ifdef JVMTI_TRACE
duke@435 866 const char *name = JvmtiTrace::safe_get_thread_name(thread);
duke@435 867 #else
duke@435 868 const char *name = "";
duke@435 869 #endif /*JVMTI_TRACE */
duke@435 870 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
duke@435 871 if (!thread->has_last_Java_frame()) {
duke@435 872 tty->print("no stack");
duke@435 873 }
duke@435 874 tty->print(") ");
duke@435 875 }
duke@435 876 tty->print_cr("]");
duke@435 877 #endif
duke@435 878 }
kamg@2511 879
kamg@2511 880 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
kamg@2511 881 nmethod* nm) {
kamg@2511 882 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
kamg@2583 883 event._event_data.compiled_method_load = nm;
dcubed@2624 884 // Keep the nmethod alive until the ServiceThread can process
dcubed@2624 885 // this deferred event.
dcubed@2624 886 nmethodLocker::lock_nmethod(nm);
kamg@2511 887 return event;
kamg@2511 888 }
kamg@2511 889
kamg@2511 890 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
dcubed@2624 891 nmethod* nm, jmethodID id, const void* code) {
kamg@2511 892 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
dcubed@2624 893 event._event_data.compiled_method_unload.nm = nm;
kamg@2583 894 event._event_data.compiled_method_unload.method_id = id;
kamg@2583 895 event._event_data.compiled_method_unload.code_begin = code;
dcubed@2624 896 // Keep the nmethod alive until the ServiceThread can process
dcubed@2624 897 // this deferred event. This will keep the memory for the
dcubed@2624 898 // generated code from being reused too early. We pass
dcubed@2624 899 // zombie_ok == true here so that our nmethod that was just
dcubed@2624 900 // made into a zombie can be locked.
dcubed@2624 901 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
kamg@2583 902 return event;
kamg@2583 903 }
dcubed@2836 904
kamg@2583 905 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
kamg@2583 906 const char* name, const void* code_begin, const void* code_end) {
kamg@2583 907 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
dcubed@2836 908 // Need to make a copy of the name since we don't know how long
dcubed@2836 909 // the event poster will keep it around after we enqueue the
dcubed@2836 910 // deferred event and return. strdup() failure is handled in
dcubed@2836 911 // the post() routine below.
dcubed@2836 912 event._event_data.dynamic_code_generated.name = os::strdup(name);
kamg@2583 913 event._event_data.dynamic_code_generated.code_begin = code_begin;
kamg@2583 914 event._event_data.dynamic_code_generated.code_end = code_end;
kamg@2511 915 return event;
kamg@2511 916 }
kamg@2511 917
kamg@2511 918 void JvmtiDeferredEvent::post() {
kamg@2583 919 assert(ServiceThread::is_service_thread(Thread::current()),
kamg@2583 920 "Service thread must post enqueued events");
kamg@2511 921 switch(_type) {
kamg@2583 922 case TYPE_COMPILED_METHOD_LOAD: {
kamg@2583 923 nmethod* nm = _event_data.compiled_method_load;
kamg@2583 924 JvmtiExport::post_compiled_method_load(nm);
dcubed@2624 925 // done with the deferred event so unlock the nmethod
kamg@2583 926 nmethodLocker::unlock_nmethod(nm);
kamg@2511 927 break;
kamg@2583 928 }
dcubed@2624 929 case TYPE_COMPILED_METHOD_UNLOAD: {
dcubed@2624 930 nmethod* nm = _event_data.compiled_method_unload.nm;
kamg@2511 931 JvmtiExport::post_compiled_method_unload(
kamg@2583 932 _event_data.compiled_method_unload.method_id,
kamg@2583 933 _event_data.compiled_method_unload.code_begin);
dcubed@2624 934 // done with the deferred event so unlock the nmethod
dcubed@2624 935 nmethodLocker::unlock_nmethod(nm);
kamg@2511 936 break;
dcubed@2624 937 }
dcubed@2836 938 case TYPE_DYNAMIC_CODE_GENERATED: {
kamg@2583 939 JvmtiExport::post_dynamic_code_generated_internal(
dcubed@2836 940 // if strdup failed give the event a default name
dcubed@2836 941 (_event_data.dynamic_code_generated.name == NULL)
dcubed@2836 942 ? "unknown_code" : _event_data.dynamic_code_generated.name,
kamg@2583 943 _event_data.dynamic_code_generated.code_begin,
kamg@2583 944 _event_data.dynamic_code_generated.code_end);
dcubed@2836 945 if (_event_data.dynamic_code_generated.name != NULL) {
dcubed@2836 946 // release our copy
dcubed@2836 947 os::free((void *)_event_data.dynamic_code_generated.name);
dcubed@2836 948 }
kamg@2511 949 break;
dcubed@2836 950 }
kamg@2511 951 default:
kamg@2511 952 ShouldNotReachHere();
kamg@2511 953 }
kamg@2511 954 }
kamg@2511 955
kamg@2511 956 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
kamg@2511 957 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
kamg@2511 958
kamg@2511 959 volatile JvmtiDeferredEventQueue::QueueNode*
kamg@2511 960 JvmtiDeferredEventQueue::_pending_list = NULL;
kamg@2511 961
kamg@2511 962 bool JvmtiDeferredEventQueue::has_events() {
kamg@2511 963 assert(Service_lock->owned_by_self(), "Must own Service_lock");
kamg@2511 964 return _queue_head != NULL || _pending_list != NULL;
kamg@2511 965 }
kamg@2511 966
kamg@2511 967 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
kamg@2511 968 assert(Service_lock->owned_by_self(), "Must own Service_lock");
kamg@2511 969
kamg@2511 970 process_pending_events();
kamg@2511 971
kamg@2511 972 // Events get added to the end of the queue (and are pulled off the front).
kamg@2511 973 QueueNode* node = new QueueNode(event);
kamg@2511 974 if (_queue_tail == NULL) {
kamg@2511 975 _queue_tail = _queue_head = node;
kamg@2511 976 } else {
kamg@2511 977 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
kamg@2511 978 _queue_tail->set_next(node);
kamg@2511 979 _queue_tail = node;
kamg@2511 980 }
kamg@2511 981
kamg@2511 982 Service_lock->notify_all();
kamg@2511 983 assert((_queue_head == NULL) == (_queue_tail == NULL),
kamg@2511 984 "Inconsistent queue markers");
kamg@2511 985 }
kamg@2511 986
kamg@2511 987 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
kamg@2511 988 assert(Service_lock->owned_by_self(), "Must own Service_lock");
kamg@2511 989
kamg@2511 990 process_pending_events();
kamg@2511 991
kamg@2511 992 assert(_queue_head != NULL, "Nothing to dequeue");
kamg@2511 993
kamg@2511 994 if (_queue_head == NULL) {
kamg@2511 995 // Just in case this happens in product; it shouldn't but let's not crash
kamg@2511 996 return JvmtiDeferredEvent();
kamg@2511 997 }
kamg@2511 998
kamg@2511 999 QueueNode* node = _queue_head;
kamg@2511 1000 _queue_head = _queue_head->next();
kamg@2511 1001 if (_queue_head == NULL) {
kamg@2511 1002 _queue_tail = NULL;
kamg@2511 1003 }
kamg@2511 1004
kamg@2511 1005 assert((_queue_head == NULL) == (_queue_tail == NULL),
kamg@2511 1006 "Inconsistent queue markers");
kamg@2511 1007
kamg@2511 1008 JvmtiDeferredEvent event = node->event();
kamg@2511 1009 delete node;
kamg@2511 1010 return event;
kamg@2511 1011 }
kamg@2511 1012
kamg@2511 1013 void JvmtiDeferredEventQueue::add_pending_event(
kamg@2511 1014 const JvmtiDeferredEvent& event) {
kamg@2511 1015
kamg@2511 1016 QueueNode* node = new QueueNode(event);
kamg@2511 1017
kamg@2511 1018 bool success = false;
kamg@2511 1019 QueueNode* prev_value = (QueueNode*)_pending_list;
kamg@2511 1020 do {
kamg@2511 1021 node->set_next(prev_value);
kamg@2511 1022 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
kamg@2511 1023 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
kamg@2511 1024 } while (prev_value != node->next());
kamg@2511 1025 }
kamg@2511 1026
kamg@2511 1027 // This method transfers any events that were added by someone NOT holding
kamg@2511 1028 // the lock into the mainline queue.
kamg@2511 1029 void JvmtiDeferredEventQueue::process_pending_events() {
kamg@2511 1030 assert(Service_lock->owned_by_self(), "Must own Service_lock");
kamg@2511 1031
kamg@2511 1032 if (_pending_list != NULL) {
kamg@2511 1033 QueueNode* head =
kamg@2511 1034 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
kamg@2511 1035
kamg@2511 1036 assert((_queue_head == NULL) == (_queue_tail == NULL),
kamg@2511 1037 "Inconsistent queue markers");
kamg@2511 1038
kamg@2511 1039 if (head != NULL) {
kamg@2511 1040 // Since we've treated the pending list as a stack (with newer
kamg@2511 1041 // events at the beginning), we need to join the bottom of the stack
kamg@2511 1042 // with the 'tail' of the queue in order to get the events in the
kamg@2511 1043 // right order. We do this by reversing the pending list and appending
kamg@2511 1044 // it to the queue.
kamg@2511 1045
kamg@2511 1046 QueueNode* new_tail = head;
kamg@2511 1047 QueueNode* new_head = NULL;
kamg@2511 1048
kamg@2511 1049 // This reverses the list
kamg@2511 1050 QueueNode* prev = new_tail;
kamg@2511 1051 QueueNode* node = new_tail->next();
kamg@2511 1052 new_tail->set_next(NULL);
kamg@2511 1053 while (node != NULL) {
kamg@2511 1054 QueueNode* next = node->next();
kamg@2511 1055 node->set_next(prev);
kamg@2511 1056 prev = node;
kamg@2511 1057 node = next;
kamg@2511 1058 }
kamg@2511 1059 new_head = prev;
kamg@2511 1060
kamg@2511 1061 // Now append the new list to the queue
kamg@2511 1062 if (_queue_tail != NULL) {
kamg@2511 1063 _queue_tail->set_next(new_head);
kamg@2511 1064 } else { // _queue_head == NULL
kamg@2511 1065 _queue_head = new_head;
kamg@2511 1066 }
kamg@2511 1067 _queue_tail = new_tail;
kamg@2511 1068 }
kamg@2511 1069 }
kamg@2511 1070 }

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