1 /* 2 * Copyright (c) 2003, 2017, 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 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "jvmtifiles/jvmtiEnv.hpp" 28 #include "memory/resourceArea.hpp" 29 #include "oops/objArrayKlass.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/oop.inline.hpp" 32 #include "prims/jvmtiEnvBase.hpp" 33 #include "prims/jvmtiEventController.inline.hpp" 34 #include "prims/jvmtiExtensions.hpp" 35 #include "prims/jvmtiImpl.hpp" 36 #include "prims/jvmtiManageCapabilities.hpp" 37 #include "prims/jvmtiTagMap.hpp" 38 #include "prims/jvmtiThreadState.inline.hpp" 39 #include "runtime/biasedLocking.hpp" 40 #include "runtime/deoptimization.hpp" 41 #include "runtime/interfaceSupport.hpp" 42 #include "runtime/jfieldIDWorkaround.hpp" 43 #include "runtime/objectMonitor.hpp" 44 #include "runtime/objectMonitor.inline.hpp" 45 #include "runtime/signature.hpp" 46 #include "runtime/thread.inline.hpp" 47 #include "runtime/threadSMR.hpp" 48 #include "runtime/vframe.hpp" 49 #include "runtime/vframe_hp.hpp" 50 #include "runtime/vmThread.hpp" 51 #include "runtime/vm_operations.hpp" 52 53 /////////////////////////////////////////////////////////////// 54 // 55 // JvmtiEnvBase 56 // 57 58 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL; 59 60 bool JvmtiEnvBase::_globally_initialized = false; 61 volatile bool JvmtiEnvBase::_needs_clean_up = false; 62 63 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 64 65 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 66 67 extern jvmtiInterface_1_ jvmti_Interface; 68 extern jvmtiInterface_1_ jvmtiTrace_Interface; 69 70 71 // perform initializations that must occur before any JVMTI environments 72 // are released but which should only be initialized once (no matter 73 // how many environments are created). 74 void 75 JvmtiEnvBase::globally_initialize() { 76 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 77 assert(_globally_initialized == false, "bad call"); 78 79 JvmtiManageCapabilities::initialize(); 80 81 // register extension functions and events 82 JvmtiExtensions::register_extensions(); 83 84 #ifdef JVMTI_TRACE 85 JvmtiTrace::initialize(); 86 #endif 87 88 _globally_initialized = true; 89 } 90 91 92 void 93 JvmtiEnvBase::initialize() { 94 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 95 96 // Add this environment to the end of the environment list (order is important) 97 { 98 // This block of code must not contain any safepoints, as list deallocation 99 // (which occurs at a safepoint) cannot occur simultaneously with this list 100 // addition. Note: NoSafepointVerifier cannot, currently, be used before 101 // threads exist. 102 JvmtiEnvIterator it; 103 JvmtiEnvBase *previous_env = NULL; 104 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 105 previous_env = env; 106 } 107 if (previous_env == NULL) { 108 _head_environment = this; 109 } else { 110 previous_env->set_next_environment(this); 111 } 112 } 113 114 if (_globally_initialized == false) { 115 globally_initialize(); 116 } 117 } 118 119 jvmtiPhase 120 JvmtiEnvBase::phase() { 121 // For the JVMTI environments possessed the can_generate_early_vmstart: 122 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START 123 if (_phase == JVMTI_PHASE_PRIMORDIAL && 124 JvmtiExport::early_vmstart_recorded() && 125 early_vmstart_env()) { 126 return JVMTI_PHASE_START; 127 } 128 return _phase; // Normal case 129 } 130 131 bool 132 JvmtiEnvBase::is_valid() { 133 jint value = 0; 134 135 // This object might not be a JvmtiEnvBase so we can't assume 136 // the _magic field is properly aligned. Get the value in a safe 137 // way and then check against JVMTI_MAGIC. 138 139 switch (sizeof(_magic)) { 140 case 2: 141 value = Bytes::get_native_u2((address)&_magic); 142 break; 143 144 case 4: 145 value = Bytes::get_native_u4((address)&_magic); 146 break; 147 148 case 8: 149 value = Bytes::get_native_u8((address)&_magic); 150 break; 151 152 default: 153 guarantee(false, "_magic field is an unexpected size"); 154 } 155 156 return value == JVMTI_MAGIC; 157 } 158 159 160 bool 161 JvmtiEnvBase::use_version_1_0_semantics() { 162 int major, minor, micro; 163 164 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 165 return major == 1 && minor == 0; // micro version doesn't matter here 166 } 167 168 169 bool 170 JvmtiEnvBase::use_version_1_1_semantics() { 171 int major, minor, micro; 172 173 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 174 return major == 1 && minor == 1; // micro version doesn't matter here 175 } 176 177 bool 178 JvmtiEnvBase::use_version_1_2_semantics() { 179 int major, minor, micro; 180 181 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 182 return major == 1 && minor == 2; // micro version doesn't matter here 183 } 184 185 186 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 187 _version = version; 188 _env_local_storage = NULL; 189 _tag_map = NULL; 190 _native_method_prefix_count = 0; 191 _native_method_prefixes = NULL; 192 _next = NULL; 193 _class_file_load_hook_ever_enabled = false; 194 195 // Moot since ClassFileLoadHook not yet enabled. 196 // But "true" will give a more predictable ClassFileLoadHook behavior 197 // for environment creation during ClassFileLoadHook. 198 _is_retransformable = true; 199 200 // all callbacks initially NULL 201 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks)); 202 203 // all capabilities initially off 204 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 205 206 // all prohibited capabilities initially off 207 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 208 209 _magic = JVMTI_MAGIC; 210 211 JvmtiEventController::env_initialize((JvmtiEnv*)this); 212 213 #ifdef JVMTI_TRACE 214 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface; 215 #else 216 _jvmti_external.functions = &jvmti_Interface; 217 #endif 218 } 219 220 221 void 222 JvmtiEnvBase::dispose() { 223 224 #ifdef JVMTI_TRACE 225 JvmtiTrace::shutdown(); 226 #endif 227 228 // Dispose of event info and let the event controller call us back 229 // in a locked state (env_dispose, below) 230 JvmtiEventController::env_dispose(this); 231 } 232 233 void 234 JvmtiEnvBase::env_dispose() { 235 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 236 237 // We have been entered with all events disabled on this environment. 238 // A race to re-enable events (by setting callbacks) is prevented by 239 // checking for a valid environment when setting callbacks (while 240 // holding the JvmtiThreadState_lock). 241 242 // Mark as invalid. 243 _magic = DISPOSED_MAGIC; 244 245 // Relinquish all capabilities. 246 jvmtiCapabilities *caps = get_capabilities(); 247 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 248 249 // Same situation as with events (see above) 250 set_native_method_prefixes(0, NULL); 251 252 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 253 set_tag_map(NULL); 254 // A tag map can be big, deallocate it now 255 if (tag_map_to_deallocate != NULL) { 256 delete tag_map_to_deallocate; 257 } 258 259 _needs_clean_up = true; 260 } 261 262 263 JvmtiEnvBase::~JvmtiEnvBase() { 264 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 265 266 // There is a small window of time during which the tag map of a 267 // disposed environment could have been reallocated. 268 // Make sure it is gone. 269 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 270 set_tag_map(NULL); 271 // A tag map can be big, deallocate it now 272 if (tag_map_to_deallocate != NULL) { 273 delete tag_map_to_deallocate; 274 } 275 276 _magic = BAD_MAGIC; 277 } 278 279 280 void 281 JvmtiEnvBase::periodic_clean_up() { 282 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 283 284 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 285 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 286 JvmtiThreadState::periodic_clean_up(); 287 288 // Unlink all invalid environments from the list of environments 289 // and deallocate them 290 JvmtiEnvIterator it; 291 JvmtiEnvBase* previous_env = NULL; 292 JvmtiEnvBase* env = it.first(); 293 while (env != NULL) { 294 if (env->is_valid()) { 295 previous_env = env; 296 env = it.next(env); 297 } else { 298 // This one isn't valid, remove it from the list and deallocate it 299 JvmtiEnvBase* defunct_env = env; 300 env = it.next(env); 301 if (previous_env == NULL) { 302 _head_environment = env; 303 } else { 304 previous_env->set_next_environment(env); 305 } 306 delete defunct_env; 307 } 308 } 309 310 } 311 312 313 void 314 JvmtiEnvBase::check_for_periodic_clean_up() { 315 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 316 317 class ThreadInsideIterationClosure: public ThreadClosure { 318 private: 319 bool _inside; 320 public: 321 ThreadInsideIterationClosure() : _inside(false) {}; 322 323 void do_thread(Thread* thread) { 324 _inside |= thread->is_inside_jvmti_env_iteration(); 325 } 326 327 bool is_inside_jvmti_env_iteration() { 328 return _inside; 329 } 330 }; 331 332 if (_needs_clean_up) { 333 // Check if we are currently iterating environment, 334 // deallocation should not occur if we are 335 ThreadInsideIterationClosure tiic; 336 Threads::threads_do(&tiic); 337 if (!tiic.is_inside_jvmti_env_iteration() && 338 !is_inside_dying_thread_env_iteration()) { 339 _needs_clean_up = false; 340 JvmtiEnvBase::periodic_clean_up(); 341 } 342 } 343 } 344 345 346 void 347 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 348 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 349 "sanity check"); 350 351 if (!_class_file_load_hook_ever_enabled) { 352 _class_file_load_hook_ever_enabled = true; 353 354 if (get_capabilities()->can_retransform_classes) { 355 _is_retransformable = true; 356 } else { 357 _is_retransformable = false; 358 359 // cannot add retransform capability after ClassFileLoadHook has been enabled 360 get_prohibited_capabilities()->can_retransform_classes = 1; 361 } 362 } 363 } 364 365 366 void 367 JvmtiEnvBase::record_class_file_load_hook_enabled() { 368 if (!_class_file_load_hook_ever_enabled) { 369 if (Threads::number_of_threads() == 0) { 370 record_first_time_class_file_load_hook_enabled(); 371 } else { 372 MutexLocker mu(JvmtiThreadState_lock); 373 record_first_time_class_file_load_hook_enabled(); 374 } 375 } 376 } 377 378 379 jvmtiError 380 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 381 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 382 "sanity check"); 383 384 int old_prefix_count = get_native_method_prefix_count(); 385 char **old_prefixes = get_native_method_prefixes(); 386 387 // allocate and install the new prefixex 388 if (prefix_count == 0 || !is_valid()) { 389 _native_method_prefix_count = 0; 390 _native_method_prefixes = NULL; 391 } else { 392 // there are prefixes, allocate an array to hold them, and fill it 393 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal); 394 if (new_prefixes == NULL) { 395 return JVMTI_ERROR_OUT_OF_MEMORY; 396 } 397 for (int i = 0; i < prefix_count; i++) { 398 char* prefix = prefixes[i]; 399 if (prefix == NULL) { 400 for (int j = 0; j < (i-1); j++) { 401 os::free(new_prefixes[j]); 402 } 403 os::free(new_prefixes); 404 return JVMTI_ERROR_NULL_POINTER; 405 } 406 prefix = os::strdup(prefixes[i]); 407 if (prefix == NULL) { 408 for (int j = 0; j < (i-1); j++) { 409 os::free(new_prefixes[j]); 410 } 411 os::free(new_prefixes); 412 return JVMTI_ERROR_OUT_OF_MEMORY; 413 } 414 new_prefixes[i] = prefix; 415 } 416 _native_method_prefix_count = prefix_count; 417 _native_method_prefixes = new_prefixes; 418 } 419 420 // now that we know the new prefixes have been successfully installed we can 421 // safely remove the old ones 422 if (old_prefix_count != 0) { 423 for (int i = 0; i < old_prefix_count; i++) { 424 os::free(old_prefixes[i]); 425 } 426 os::free(old_prefixes); 427 } 428 429 return JVMTI_ERROR_NONE; 430 } 431 432 433 // Collect all the prefixes which have been set in any JVM TI environments 434 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 435 // order of environments and the order of prefixes within each environment. 436 // Return in a resource allocated array. 437 char** 438 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 439 assert(Threads::number_of_threads() == 0 || 440 SafepointSynchronize::is_at_safepoint() || 441 JvmtiThreadState_lock->is_locked(), 442 "sanity check"); 443 444 int total_count = 0; 445 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 446 447 JvmtiEnvIterator it; 448 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 449 int prefix_count = env->get_native_method_prefix_count(); 450 char** prefixes = env->get_native_method_prefixes(); 451 for (int j = 0; j < prefix_count; j++) { 452 // retrieve a prefix and so that it is safe against asynchronous changes 453 // copy it into the resource area 454 char* prefix = prefixes[j]; 455 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 456 strcpy(prefix_copy, prefix); 457 prefix_array->at_put_grow(total_count++, prefix_copy); 458 } 459 } 460 461 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 462 char** p = all_prefixes; 463 for (int i = 0; i < total_count; ++i) { 464 *p++ = prefix_array->at(i); 465 } 466 *count_ptr = total_count; 467 return all_prefixes; 468 } 469 470 void 471 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 472 jint size_of_callbacks) { 473 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 474 475 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 476 477 // clear in either case to be sure we got any gap between sizes 478 memset(&_event_callbacks, 0, byte_cnt); 479 480 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 481 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 482 // occurs after the boiler-plate environment check and before the lock is acquired. 483 if (callbacks != NULL && is_valid()) { 484 if (size_of_callbacks < (jint)byte_cnt) { 485 byte_cnt = size_of_callbacks; 486 } 487 memcpy(&_event_callbacks, callbacks, byte_cnt); 488 } 489 } 490 491 492 // In the fullness of time, all users of the method should instead 493 // directly use allocate, besides being cleaner and faster, this will 494 // mean much better out of memory handling 495 unsigned char * 496 JvmtiEnvBase::jvmtiMalloc(jlong size) { 497 unsigned char* mem = NULL; 498 jvmtiError result = allocate(size, &mem); 499 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 500 return mem; 501 } 502 503 504 // 505 // Threads 506 // 507 508 jobject * 509 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) { 510 if (length == 0) { 511 return NULL; 512 } 513 514 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length); 515 NULL_CHECK(objArray, NULL); 516 517 for (int i=0; i<length; i++) { 518 objArray[i] = jni_reference(handles[i]); 519 } 520 return objArray; 521 } 522 523 jthread * 524 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 525 return (jthread *) new_jobjectArray(length,handles); 526 } 527 528 jthreadGroup * 529 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) { 530 return (jthreadGroup *) new_jobjectArray(length,handles); 531 } 532 533 // return the vframe on the specified thread and depth, NULL if no such frame 534 vframe* 535 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) { 536 if (!java_thread->has_last_Java_frame()) { 537 return NULL; 538 } 539 RegisterMap reg_map(java_thread); 540 vframe *vf = java_thread->last_java_vframe(®_map); 541 int d = 0; 542 while ((vf != NULL) && (d < depth)) { 543 vf = vf->java_sender(); 544 d++; 545 } 546 return vf; 547 } 548 549 550 // 551 // utilities: JNI objects 552 // 553 554 555 jclass 556 JvmtiEnvBase::get_jni_class_non_null(Klass* k) { 557 assert(k != NULL, "k != NULL"); 558 Thread *thread = Thread::current(); 559 return (jclass)jni_reference(Handle(thread, k->java_mirror())); 560 } 561 562 // 563 // Field Information 564 // 565 566 bool 567 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) { 568 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 569 return false; 570 } 571 bool found = false; 572 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 573 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 574 found = id->find_local_field(fd); 575 } else { 576 // Non-static field. The fieldID is really the offset of the field within the object. 577 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 578 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 579 } 580 return found; 581 } 582 583 // 584 // Object Monitor Information 585 // 586 587 // 588 // Count the number of objects for a lightweight monitor. The hobj 589 // parameter is object that owns the monitor so this routine will 590 // count the number of times the same object was locked by frames 591 // in java_thread. 592 // 593 jint 594 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 595 jint ret = 0; 596 if (!java_thread->has_last_Java_frame()) { 597 return ret; // no Java frames so no monitors 598 } 599 600 ResourceMark rm; 601 HandleMark hm; 602 RegisterMap reg_map(java_thread); 603 604 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL; 605 jvf = jvf->java_sender()) { 606 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 607 if (!mons->is_empty()) { 608 for (int i = 0; i < mons->length(); i++) { 609 MonitorInfo *mi = mons->at(i); 610 if (mi->owner_is_scalar_replaced()) continue; 611 612 // see if owner of the monitor is our object 613 if (mi->owner() != NULL && mi->owner() == hobj()) { 614 ret++; 615 } 616 } 617 } 618 } 619 return ret; 620 } 621 622 623 624 jvmtiError 625 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) { 626 #ifdef ASSERT 627 uint32_t debug_bits = 0; 628 #endif 629 assert((SafepointSynchronize::is_at_safepoint() || 630 java_thread->is_thread_fully_suspended(false, &debug_bits)), 631 "at safepoint or target thread is suspended"); 632 oop obj = NULL; 633 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 634 if (mon == NULL) { 635 // thread is not doing an Object.wait() call 636 mon = java_thread->current_pending_monitor(); 637 if (mon != NULL) { 638 // The thread is trying to enter() or raw_enter() an ObjectMonitor. 639 obj = (oop)mon->object(); 640 // If obj == NULL, then ObjectMonitor is raw which doesn't count 641 // as contended for this API 642 } 643 // implied else: no contended ObjectMonitor 644 } else { 645 // thread is doing an Object.wait() call 646 obj = (oop)mon->object(); 647 assert(obj != NULL, "Object.wait() should have an object"); 648 } 649 650 if (obj == NULL) { 651 *monitor_ptr = NULL; 652 } else { 653 HandleMark hm; 654 Handle hobj(Thread::current(), obj); 655 *monitor_ptr = jni_reference(calling_thread, hobj); 656 } 657 return JVMTI_ERROR_NONE; 658 } 659 660 661 jvmtiError 662 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 663 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 664 jvmtiError err = JVMTI_ERROR_NONE; 665 #ifdef ASSERT 666 uint32_t debug_bits = 0; 667 #endif 668 assert((SafepointSynchronize::is_at_safepoint() || 669 java_thread->is_thread_fully_suspended(false, &debug_bits)), 670 "at safepoint or target thread is suspended"); 671 672 if (java_thread->has_last_Java_frame()) { 673 ResourceMark rm; 674 HandleMark hm; 675 RegisterMap reg_map(java_thread); 676 677 int depth = 0; 678 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL; 679 jvf = jvf->java_sender()) { 680 if (depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 681 // add locked objects for this frame into list 682 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1); 683 if (err != JVMTI_ERROR_NONE) { 684 return err; 685 } 686 } 687 } 688 } 689 690 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 691 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this); 692 ObjectSynchronizer::monitors_iterate(&jmc); 693 err = jmc.error(); 694 695 return err; 696 } 697 698 // Save JNI local handles for any objects that this frame owns. 699 jvmtiError 700 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread, 701 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) { 702 jvmtiError err = JVMTI_ERROR_NONE; 703 ResourceMark rm; 704 705 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 706 if (mons->is_empty()) { 707 return err; // this javaVFrame holds no monitors 708 } 709 710 HandleMark hm; 711 oop wait_obj = NULL; 712 { 713 // save object of current wait() call (if any) for later comparison 714 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 715 if (mon != NULL) { 716 wait_obj = (oop)mon->object(); 717 } 718 } 719 oop pending_obj = NULL; 720 { 721 // save object of current enter() call (if any) for later comparison 722 ObjectMonitor *mon = java_thread->current_pending_monitor(); 723 if (mon != NULL) { 724 pending_obj = (oop)mon->object(); 725 } 726 } 727 728 for (int i = 0; i < mons->length(); i++) { 729 MonitorInfo *mi = mons->at(i); 730 731 if (mi->owner_is_scalar_replaced()) continue; 732 733 oop obj = mi->owner(); 734 if (obj == NULL) { 735 // this monitor doesn't have an owning object so skip it 736 continue; 737 } 738 739 if (wait_obj == obj) { 740 // the thread is waiting on this monitor so it isn't really owned 741 continue; 742 } 743 744 if (pending_obj == obj) { 745 // the thread is pending on this monitor so it isn't really owned 746 continue; 747 } 748 749 if (owned_monitors_list->length() > 0) { 750 // Our list has at least one object on it so we have to check 751 // for recursive object locking 752 bool found = false; 753 for (int j = 0; j < owned_monitors_list->length(); j++) { 754 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 755 oop check = JNIHandles::resolve(jobj); 756 if (check == obj) { 757 found = true; // we found the object 758 break; 759 } 760 } 761 762 if (found) { 763 // already have this object so don't include it 764 continue; 765 } 766 } 767 768 // add the owning object to our list 769 jvmtiMonitorStackDepthInfo *jmsdi; 770 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 771 if (err != JVMTI_ERROR_NONE) { 772 return err; 773 } 774 Handle hobj(Thread::current(), obj); 775 jmsdi->monitor = jni_reference(calling_thread, hobj); 776 jmsdi->stack_depth = stack_depth; 777 owned_monitors_list->append(jmsdi); 778 } 779 780 return err; 781 } 782 783 jvmtiError 784 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 785 jint start_depth, jint max_count, 786 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 787 #ifdef ASSERT 788 uint32_t debug_bits = 0; 789 #endif 790 assert((SafepointSynchronize::is_at_safepoint() || 791 java_thread->is_thread_fully_suspended(false, &debug_bits)), 792 "at safepoint or target thread is suspended"); 793 int count = 0; 794 if (java_thread->has_last_Java_frame()) { 795 RegisterMap reg_map(java_thread); 796 Thread* current_thread = Thread::current(); 797 ResourceMark rm(current_thread); 798 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 799 HandleMark hm(current_thread); 800 if (start_depth != 0) { 801 if (start_depth > 0) { 802 for (int j = 0; j < start_depth && jvf != NULL; j++) { 803 jvf = jvf->java_sender(); 804 } 805 if (jvf == NULL) { 806 // start_depth is deeper than the stack depth 807 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 808 } 809 } else { // start_depth < 0 810 // we are referencing the starting depth based on the oldest 811 // part of the stack. 812 // optimize to limit the number of times that java_sender() is called 813 javaVFrame *jvf_cursor = jvf; 814 javaVFrame *jvf_prev = NULL; 815 javaVFrame *jvf_prev_prev = NULL; 816 int j = 0; 817 while (jvf_cursor != NULL) { 818 jvf_prev_prev = jvf_prev; 819 jvf_prev = jvf_cursor; 820 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) { 821 jvf_cursor = jvf_cursor->java_sender(); 822 } 823 } 824 if (j == start_depth) { 825 // previous pointer is exactly where we want to start 826 jvf = jvf_prev; 827 } else { 828 // we need to back up further to get to the right place 829 if (jvf_prev_prev == NULL) { 830 // the -start_depth is greater than the stack depth 831 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 832 } 833 // j now is the number of frames on the stack starting with 834 // jvf_prev, we start from jvf_prev_prev and move older on 835 // the stack that many, the result is -start_depth frames 836 // remaining. 837 jvf = jvf_prev_prev; 838 for (; j < 0; j++) { 839 jvf = jvf->java_sender(); 840 } 841 } 842 } 843 } 844 for (; count < max_count && jvf != NULL; count++) { 845 frame_buffer[count].method = jvf->method()->jmethod_id(); 846 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 847 jvf = jvf->java_sender(); 848 } 849 } else { 850 if (start_depth != 0) { 851 // no frames and there is a starting depth 852 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 853 } 854 } 855 *count_ptr = count; 856 return JVMTI_ERROR_NONE; 857 } 858 859 jvmtiError 860 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) { 861 assert((state != NULL), 862 "JavaThread should create JvmtiThreadState before calling this method"); 863 *count_ptr = state->count_frames(); 864 return JVMTI_ERROR_NONE; 865 } 866 867 jvmtiError 868 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 869 jmethodID* method_ptr, jlocation* location_ptr) { 870 #ifdef ASSERT 871 uint32_t debug_bits = 0; 872 #endif 873 assert((SafepointSynchronize::is_at_safepoint() || 874 java_thread->is_thread_fully_suspended(false, &debug_bits)), 875 "at safepoint or target thread is suspended"); 876 Thread* current_thread = Thread::current(); 877 ResourceMark rm(current_thread); 878 879 vframe *vf = vframeFor(java_thread, depth); 880 if (vf == NULL) { 881 return JVMTI_ERROR_NO_MORE_FRAMES; 882 } 883 884 // vframeFor should return a java frame. If it doesn't 885 // it means we've got an internal error and we return the 886 // error in product mode. In debug mode we will instead 887 // attempt to cast the vframe to a javaVFrame and will 888 // cause an assertion/crash to allow further diagnosis. 889 #ifdef PRODUCT 890 if (!vf->is_java_frame()) { 891 return JVMTI_ERROR_INTERNAL; 892 } 893 #endif 894 895 HandleMark hm(current_thread); 896 javaVFrame *jvf = javaVFrame::cast(vf); 897 Method* method = jvf->method(); 898 if (method->is_native()) { 899 *location_ptr = -1; 900 } else { 901 *location_ptr = jvf->bci(); 902 } 903 *method_ptr = method->jmethod_id(); 904 905 return JVMTI_ERROR_NONE; 906 } 907 908 909 jvmtiError 910 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 911 HandleMark hm; 912 Handle hobj; 913 914 Thread* current_thread = Thread::current(); 915 bool at_safepoint = SafepointSynchronize::is_at_safepoint(); 916 917 // Check arguments 918 { 919 oop mirror = JNIHandles::resolve_external_guard(object); 920 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 921 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 922 923 hobj = Handle(current_thread, mirror); 924 } 925 926 JavaThread *owning_thread = NULL; 927 ObjectMonitor *mon = NULL; 928 jvmtiMonitorUsage ret = { 929 NULL, 0, 0, NULL, 0, NULL 930 }; 931 932 uint32_t debug_bits = 0; 933 // first derive the object's owner and entry_count (if any) 934 { 935 // Revoke any biases before querying the mark word 936 if (at_safepoint) { 937 BiasedLocking::revoke_at_safepoint(hobj); 938 } else { 939 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread); 940 } 941 942 address owner = NULL; 943 { 944 markOop mark = hobj()->mark(); 945 946 if (!mark->has_monitor()) { 947 // this object has a lightweight monitor 948 949 if (mark->has_locker()) { 950 owner = (address)mark->locker(); // save the address of the Lock word 951 } 952 // implied else: no owner 953 } else { 954 // this object has a heavyweight monitor 955 mon = mark->monitor(); 956 957 // The owner field of a heavyweight monitor may be NULL for no 958 // owner, a JavaThread * or it may still be the address of the 959 // Lock word in a JavaThread's stack. A monitor can be inflated 960 // by a non-owning JavaThread, but only the owning JavaThread 961 // can change the owner field from the Lock word to the 962 // JavaThread * and it may not have done that yet. 963 owner = (address)mon->owner(); 964 } 965 } 966 967 if (owner != NULL) { 968 // Use current thread since function can be called from a 969 // JavaThread or the VMThread. 970 ThreadsListHandle tlh; 971 // This monitor is owned so we have to find the owning JavaThread. 972 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner); 973 // Cannot assume (owning_thread != NULL) here because this function 974 // may not have been called at a safepoint and the owning_thread 975 // might not be suspended. 976 if (owning_thread != NULL) { 977 // The monitor's owner either has to be the current thread, at safepoint 978 // or it has to be suspended. Any of these conditions will prevent both 979 // contending and waiting threads from modifying the state of 980 // the monitor. 981 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) { 982 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED 983 // will not make it back to the JVM/TI agent. The error code will 984 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which 985 // will retry the call via a VM_GetObjectMonitorUsage VM op. 986 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 987 } 988 HandleMark hm; 989 Handle th(current_thread, owning_thread->threadObj()); 990 ret.owner = (jthread)jni_reference(calling_thread, th); 991 } 992 // implied else: no owner 993 } // ThreadsListHandle is destroyed here. 994 995 if (owning_thread != NULL) { // monitor is owned 996 // The recursions field of a monitor does not reflect recursions 997 // as lightweight locks before inflating the monitor are not included. 998 // We have to count the number of recursive monitor entries the hard way. 999 // We pass a handle to survive any GCs along the way. 1000 ResourceMark rm; 1001 ret.entry_count = count_locked_objects(owning_thread, hobj); 1002 } 1003 // implied else: entry_count == 0 1004 } 1005 1006 jint nWant = 0, nWait = 0; 1007 if (mon != NULL) { 1008 // this object has a heavyweight monitor 1009 nWant = mon->contentions(); // # of threads contending for monitor 1010 nWait = mon->waiters(); // # of threads in Object.wait() 1011 ret.waiter_count = nWant + nWait; 1012 ret.notify_waiter_count = nWait; 1013 } else { 1014 // this object has a lightweight monitor 1015 ret.waiter_count = 0; 1016 ret.notify_waiter_count = 0; 1017 } 1018 1019 // Allocate memory for heavyweight and lightweight monitor. 1020 jvmtiError err; 1021 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1022 if (err != JVMTI_ERROR_NONE) { 1023 return err; 1024 } 1025 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1026 (unsigned char**)&ret.notify_waiters); 1027 if (err != JVMTI_ERROR_NONE) { 1028 deallocate((unsigned char*)ret.waiters); 1029 return err; 1030 } 1031 1032 // now derive the rest of the fields 1033 if (mon != NULL) { 1034 // this object has a heavyweight monitor 1035 1036 // Number of waiters may actually be less than the waiter count. 1037 // So NULL out memory so that unused memory will be NULL. 1038 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1039 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1040 1041 if (ret.waiter_count > 0) { 1042 // we have contending and/or waiting threads 1043 HandleMark hm; 1044 // Use current thread since function can be called from a 1045 // JavaThread or the VMThread. 1046 ThreadsListHandle tlh; 1047 if (nWant > 0) { 1048 // we have contending threads 1049 ResourceMark rm; 1050 // get_pending_threads returns only java thread so we do not need to 1051 // check for non java threads. 1052 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon); 1053 if (wantList->length() < nWant) { 1054 // robustness: the pending list has gotten smaller 1055 nWant = wantList->length(); 1056 } 1057 for (int i = 0; i < nWant; i++) { 1058 JavaThread *pending_thread = wantList->at(i); 1059 // If the monitor has no owner, then a non-suspended contending 1060 // thread could potentially change the state of the monitor by 1061 // entering it. The JVM/TI spec doesn't allow this. 1062 if (owning_thread == NULL && !at_safepoint & 1063 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) { 1064 if (ret.owner != NULL) { 1065 destroy_jni_reference(calling_thread, ret.owner); 1066 } 1067 for (int j = 0; j < i; j++) { 1068 destroy_jni_reference(calling_thread, ret.waiters[j]); 1069 } 1070 deallocate((unsigned char*)ret.waiters); 1071 deallocate((unsigned char*)ret.notify_waiters); 1072 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1073 } 1074 Handle th(current_thread, pending_thread->threadObj()); 1075 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1076 } 1077 } 1078 if (nWait > 0) { 1079 // we have threads in Object.wait() 1080 int offset = nWant; // add after any contending threads 1081 ObjectWaiter *waiter = mon->first_waiter(); 1082 for (int i = 0, j = 0; i < nWait; i++) { 1083 if (waiter == NULL) { 1084 // robustness: the waiting list has gotten smaller 1085 nWait = j; 1086 break; 1087 } 1088 Thread *t = mon->thread_of_waiter(waiter); 1089 if (t != NULL && t->is_Java_thread()) { 1090 JavaThread *wjava_thread = (JavaThread *)t; 1091 // If the thread was found on the ObjectWaiter list, then 1092 // it has not been notified. This thread can't change the 1093 // state of the monitor so it doesn't need to be suspended. 1094 Handle th(current_thread, wjava_thread->threadObj()); 1095 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th); 1096 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th); 1097 } 1098 waiter = mon->next_waiter(waiter); 1099 } 1100 } 1101 } // ThreadsListHandle is destroyed here. 1102 1103 // Adjust count. nWant and nWait count values may be less than original. 1104 ret.waiter_count = nWant + nWait; 1105 ret.notify_waiter_count = nWait; 1106 } else { 1107 // this object has a lightweight monitor and we have nothing more 1108 // to do here because the defaults are just fine. 1109 } 1110 1111 // we don't update return parameter unless everything worked 1112 *info_ptr = ret; 1113 1114 return JVMTI_ERROR_NONE; 1115 } 1116 1117 ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1118 _env = env; 1119 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true); 1120 _failed = false; 1121 } 1122 ResourceTracker::~ResourceTracker() { 1123 if (_failed) { 1124 for (int i=0; i<_allocations->length(); i++) { 1125 _env->deallocate(_allocations->at(i)); 1126 } 1127 } 1128 delete _allocations; 1129 } 1130 1131 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1132 unsigned char *ptr; 1133 jvmtiError err = _env->allocate(size, &ptr); 1134 if (err == JVMTI_ERROR_NONE) { 1135 _allocations->append(ptr); 1136 *mem_ptr = ptr; 1137 } else { 1138 *mem_ptr = NULL; 1139 _failed = true; 1140 } 1141 return err; 1142 } 1143 1144 unsigned char* ResourceTracker::allocate(jlong size) { 1145 unsigned char* ptr; 1146 allocate(size, &ptr); 1147 return ptr; 1148 } 1149 1150 char* ResourceTracker::strdup(const char* str) { 1151 char *dup_str = (char*)allocate(strlen(str)+1); 1152 if (dup_str != NULL) { 1153 strcpy(dup_str, str); 1154 } 1155 return dup_str; 1156 } 1157 1158 struct StackInfoNode { 1159 struct StackInfoNode *next; 1160 jvmtiStackInfo info; 1161 }; 1162 1163 // Create a jvmtiStackInfo inside a linked list node and create a 1164 // buffer for the frame information, both allocated as resource objects. 1165 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1166 // Note that either or both of thr and thread_oop 1167 // may be null if the thread is new or has exited. 1168 void 1169 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1170 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1171 1172 jint state = 0; 1173 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1174 jvmtiStackInfo *infop = &(node->info); 1175 node->next = head(); 1176 set_head(node); 1177 infop->frame_count = 0; 1178 infop->thread = jt; 1179 1180 if (thread_oop != NULL) { 1181 // get most state bits 1182 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 1183 } 1184 1185 if (thr != NULL) { // add more state bits if there is a JavaThead to query 1186 // same as is_being_ext_suspended() but without locking 1187 if (thr->is_ext_suspended() || thr->is_external_suspend()) { 1188 state |= JVMTI_THREAD_STATE_SUSPENDED; 1189 } 1190 JavaThreadState jts = thr->thread_state(); 1191 if (jts == _thread_in_native) { 1192 state |= JVMTI_THREAD_STATE_IN_NATIVE; 1193 } 1194 OSThread* osThread = thr->osthread(); 1195 if (osThread != NULL && osThread->interrupted()) { 1196 state |= JVMTI_THREAD_STATE_INTERRUPTED; 1197 } 1198 } 1199 infop->state = state; 1200 1201 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1202 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1203 env()->get_stack_trace(thr, 0, max_frame_count(), 1204 infop->frame_buffer, &(infop->frame_count)); 1205 } else { 1206 infop->frame_buffer = NULL; 1207 infop->frame_count = 0; 1208 } 1209 _frame_count_total += infop->frame_count; 1210 } 1211 1212 // Based on the stack information in the linked list, allocate memory 1213 // block to return and fill it from the info in the linked list. 1214 void 1215 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) { 1216 // do I need to worry about alignment issues? 1217 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1218 + _frame_count_total * sizeof(jvmtiFrameInfo); 1219 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1220 1221 // pointers to move through the newly allocated space as it is filled in 1222 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1223 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1224 1225 // copy information in resource area into allocated buffer 1226 // insert stack info backwards since linked list is backwards 1227 // insert frame info forwards 1228 // walk the StackInfoNodes 1229 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) { 1230 jint frame_count = sin->info.frame_count; 1231 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1232 --si; 1233 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1234 if (frames_size == 0) { 1235 si->frame_buffer = NULL; 1236 } else { 1237 memcpy(fi, sin->info.frame_buffer, frames_size); 1238 si->frame_buffer = fi; // point to the new allocated copy of the frames 1239 fi += frame_count; 1240 } 1241 } 1242 assert(si == _stack_info, "the last copied stack info must be the first record"); 1243 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1244 "the last copied frame info must be the last record"); 1245 } 1246 1247 1248 void 1249 VM_GetThreadListStackTraces::doit() { 1250 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1251 1252 ResourceMark rm; 1253 ThreadsListHandle tlh; 1254 for (int i = 0; i < _thread_count; ++i) { 1255 jthread jt = _thread_list[i]; 1256 JavaThread* java_thread = NULL; 1257 oop thread_oop = NULL; 1258 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop); 1259 if (err != JVMTI_ERROR_NONE) { 1260 // We got an error code so we don't have a JavaThread *, but 1261 // only return an error from here if we didn't get a valid 1262 // thread_oop. 1263 if (thread_oop == NULL) { 1264 set_result(err); 1265 return; 1266 } 1267 // We have a valid thread_oop. 1268 } 1269 fill_frames(jt, java_thread, thread_oop); 1270 } 1271 allocate_and_fill_stacks(_thread_count); 1272 } 1273 1274 void 1275 VM_GetAllStackTraces::doit() { 1276 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1277 1278 ResourceMark rm; 1279 _final_thread_count = 0; 1280 { 1281 ThreadsListHandle tlh; 1282 JavaThreadIterator jti(tlh.list()); 1283 for (JavaThread *jt = jti.first(); jt != NULL; jt = jti.next()) { 1284 oop thread_oop = jt->threadObj(); 1285 if (thread_oop != NULL && 1286 !jt->is_exiting() && 1287 java_lang_Thread::is_alive(thread_oop) && 1288 !jt->is_hidden_from_external_view()) { 1289 ++_final_thread_count; 1290 // Handle block of the calling thread is used to create local refs. 1291 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1292 jt, thread_oop); 1293 } 1294 } 1295 } 1296 allocate_and_fill_stacks(_final_thread_count); 1297 } 1298 1299 // Verifies that the top frame is a java frame in an expected state. 1300 // Deoptimizes frame if needed. 1301 // Checks that the frame method signature matches the return type (tos). 1302 // HandleMark must be defined in the caller only. 1303 // It is to keep a ret_ob_h handle alive after return to the caller. 1304 jvmtiError 1305 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread, 1306 jvalue value, TosState tos, Handle* ret_ob_h) { 1307 ResourceMark rm(current_thread); 1308 1309 vframe *vf = vframeFor(java_thread, 0); 1310 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES); 1311 1312 javaVFrame *jvf = (javaVFrame*) vf; 1313 if (!vf->is_java_frame() || jvf->method()->is_native()) { 1314 return JVMTI_ERROR_OPAQUE_FRAME; 1315 } 1316 1317 // If the frame is a compiled one, need to deoptimize it. 1318 if (vf->is_compiled_frame()) { 1319 if (!vf->fr().can_be_deoptimized()) { 1320 return JVMTI_ERROR_OPAQUE_FRAME; 1321 } 1322 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 1323 } 1324 1325 // Get information about method return type 1326 Symbol* signature = jvf->method()->signature(); 1327 1328 ResultTypeFinder rtf(signature); 1329 TosState fr_tos = as_TosState(rtf.type()); 1330 if (fr_tos != tos) { 1331 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) { 1332 return JVMTI_ERROR_TYPE_MISMATCH; 1333 } 1334 } 1335 1336 // Check that the jobject class matches the return type signature. 1337 jobject jobj = value.l; 1338 if (tos == atos && jobj != NULL) { // NULL reference is allowed 1339 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj)); 1340 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 1341 Klass* ob_k = ob_h()->klass(); 1342 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT); 1343 1344 // Method return type signature. 1345 char* ty_sign = 1 + strchr(signature->as_C_string(), ')'); 1346 1347 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) { 1348 return JVMTI_ERROR_TYPE_MISMATCH; 1349 } 1350 *ret_ob_h = ob_h; 1351 } 1352 return JVMTI_ERROR_NONE; 1353 } /* end check_top_frame */ 1354 1355 1356 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 1357 // Main difference is on the last stage in the interpreter. 1358 // The PopFrame stops method execution to continue execution 1359 // from the same method call instruction. 1360 // The ForceEarlyReturn forces return from method so the execution 1361 // continues at the bytecode following the method call. 1362 1363 // Threads_lock NOT held, java_thread not protected by lock 1364 // java_thread - pre-checked 1365 1366 jvmtiError 1367 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) { 1368 JavaThread* current_thread = JavaThread::current(); 1369 HandleMark hm(current_thread); 1370 uint32_t debug_bits = 0; 1371 1372 // retrieve or create the state 1373 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 1374 if (state == NULL) { 1375 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1376 } 1377 1378 // Check if java_thread is fully suspended 1379 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) { 1380 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1381 } 1382 1383 // Check to see if a ForceEarlyReturn was already in progress 1384 if (state->is_earlyret_pending()) { 1385 // Probably possible for JVMTI clients to trigger this, but the 1386 // JPDA backend shouldn't allow this to happen 1387 return JVMTI_ERROR_INTERNAL; 1388 } 1389 { 1390 // The same as for PopFrame. Workaround bug: 1391 // 4812902: popFrame hangs if the method is waiting at a synchronize 1392 // Catch this condition and return an error to avoid hanging. 1393 // Now JVMTI spec allows an implementation to bail out with an opaque 1394 // frame error. 1395 OSThread* osThread = java_thread->osthread(); 1396 if (osThread->get_state() == MONITOR_WAIT) { 1397 return JVMTI_ERROR_OPAQUE_FRAME; 1398 } 1399 } 1400 Handle ret_ob_h; 1401 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h); 1402 if (err != JVMTI_ERROR_NONE) { 1403 return err; 1404 } 1405 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL, 1406 "return object oop must not be NULL if jobject is not NULL"); 1407 1408 // Update the thread state to reflect that the top frame must be 1409 // forced to return. 1410 // The current frame will be returned later when the suspended 1411 // thread is resumed and right before returning from VM to Java. 1412 // (see call_VM_base() in assembler_<cpu>.cpp). 1413 1414 state->set_earlyret_pending(); 1415 state->set_earlyret_oop(ret_ob_h()); 1416 state->set_earlyret_value(value, tos); 1417 1418 // Set pending step flag for this early return. 1419 // It is cleared when next step event is posted. 1420 state->set_pending_step_for_earlyret(); 1421 1422 return JVMTI_ERROR_NONE; 1423 } /* end force_early_return */ 1424 1425 void 1426 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 1427 if ( _error != JVMTI_ERROR_NONE) { 1428 // Error occurred in previous iteration so no need to add 1429 // to the list. 1430 return; 1431 } 1432 if (mon->owner() == _java_thread ) { 1433 // Filter out on stack monitors collected during stack walk. 1434 oop obj = (oop)mon->object(); 1435 bool found = false; 1436 for (int j = 0; j < _owned_monitors_list->length(); j++) { 1437 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 1438 oop check = JNIHandles::resolve(jobj); 1439 if (check == obj) { 1440 // On stack monitor already collected during the stack walk. 1441 found = true; 1442 break; 1443 } 1444 } 1445 if (found == false) { 1446 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 1447 jvmtiError err; 1448 jvmtiMonitorStackDepthInfo *jmsdi; 1449 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1450 if (err != JVMTI_ERROR_NONE) { 1451 _error = err; 1452 return; 1453 } 1454 Handle hobj(Thread::current(), obj); 1455 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 1456 // stack depth is unknown for this monitor. 1457 jmsdi->stack_depth = -1; 1458 _owned_monitors_list->append(jmsdi); 1459 } 1460 } 1461 } 1462 1463 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL; 1464 1465 jvmtiError 1466 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) { 1467 ResourceMark rm; 1468 MutexLocker ml(Module_lock); 1469 1470 _tbl = new GrowableArray<OopHandle>(77); 1471 if (_tbl == NULL) { 1472 return JVMTI_ERROR_OUT_OF_MEMORY; 1473 } 1474 1475 // Iterate over all the modules loaded to the system. 1476 ClassLoaderDataGraph::modules_do(&do_module); 1477 1478 jint len = _tbl->length(); 1479 guarantee(len > 0, "at least one module must be present"); 1480 1481 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject))); 1482 if (array == NULL) { 1483 return JVMTI_ERROR_OUT_OF_MEMORY; 1484 } 1485 for (jint idx = 0; idx < len; idx++) { 1486 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve()); 1487 } 1488 _tbl = NULL; 1489 *modules_ptr = array; 1490 *module_count_ptr = len; 1491 return JVMTI_ERROR_NONE; 1492 } 1493 1494 void 1495 VM_UpdateForPopTopFrame::doit() { 1496 JavaThread* jt = _state->get_thread(); 1497 ThreadsListHandle tlh; 1498 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1499 _state->update_for_pop_top_frame(); 1500 } else { 1501 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1502 } 1503 } 1504 1505 void 1506 VM_SetFramePop::doit() { 1507 JavaThread* jt = _state->get_thread(); 1508 ThreadsListHandle tlh; 1509 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1510 int frame_number = _state->count_frames() - _depth; 1511 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number); 1512 } else { 1513 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1514 } 1515 } 1516 1517 void 1518 VM_GetOwnedMonitorInfo::doit() { 1519 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1520 ThreadsListHandle tlh; 1521 if (_java_thread != NULL && tlh.includes(_java_thread) 1522 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1523 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread, 1524 _owned_monitors_list); 1525 } 1526 } 1527 1528 void 1529 VM_GetCurrentContendedMonitor::doit() { 1530 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1531 ThreadsListHandle tlh; 1532 if (_java_thread != NULL && tlh.includes(_java_thread) 1533 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1534 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr); 1535 } 1536 } 1537 1538 void 1539 VM_GetStackTrace::doit() { 1540 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1541 ThreadsListHandle tlh; 1542 if (_java_thread != NULL && tlh.includes(_java_thread) 1543 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1544 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread, 1545 _start_depth, _max_count, 1546 _frame_buffer, _count_ptr); 1547 } 1548 } 1549 1550 void 1551 VM_GetFrameCount::doit() { 1552 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1553 JavaThread* jt = _state->get_thread(); 1554 ThreadsListHandle tlh; 1555 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1556 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr); 1557 } 1558 } 1559 1560 void 1561 VM_GetFrameLocation::doit() { 1562 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1563 ThreadsListHandle tlh; 1564 if (_java_thread != NULL && tlh.includes(_java_thread) 1565 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1566 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth, 1567 _method_ptr, _location_ptr); 1568 } 1569 }