1 /* 2 * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/classLoaderDataGraph.hpp" 27 #include "classfile/moduleEntry.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "jvmtifiles/jvmtiEnv.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "oops/objArrayKlass.hpp" 32 #include "oops/objArrayOop.hpp" 33 #include "oops/oop.inline.hpp" 34 #include "oops/oopHandle.inline.hpp" 35 #include "prims/jvmtiEnvBase.hpp" 36 #include "prims/jvmtiEventController.inline.hpp" 37 #include "prims/jvmtiExtensions.hpp" 38 #include "prims/jvmtiImpl.hpp" 39 #include "prims/jvmtiManageCapabilities.hpp" 40 #include "prims/jvmtiTagMap.hpp" 41 #include "prims/jvmtiThreadState.inline.hpp" 42 #include "runtime/biasedLocking.hpp" 43 #include "runtime/deoptimization.hpp" 44 #include "runtime/frame.inline.hpp" 45 #include "runtime/handles.inline.hpp" 46 #include "runtime/interfaceSupport.inline.hpp" 47 #include "runtime/jfieldIDWorkaround.hpp" 48 #include "runtime/jniHandles.inline.hpp" 49 #include "runtime/objectMonitor.hpp" 50 #include "runtime/objectMonitor.inline.hpp" 51 #include "runtime/signature.hpp" 52 #include "runtime/thread.inline.hpp" 53 #include "runtime/threadSMR.hpp" 54 #include "runtime/vframe.hpp" 55 #include "runtime/vframe_hp.hpp" 56 #include "runtime/vmThread.hpp" 57 #include "runtime/vmOperations.hpp" 58 59 /////////////////////////////////////////////////////////////// 60 // 61 // JvmtiEnvBase 62 // 63 64 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL; 65 66 bool JvmtiEnvBase::_globally_initialized = false; 67 volatile bool JvmtiEnvBase::_needs_clean_up = false; 68 69 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 70 71 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 72 73 extern jvmtiInterface_1_ jvmti_Interface; 74 extern jvmtiInterface_1_ jvmtiTrace_Interface; 75 76 77 // perform initializations that must occur before any JVMTI environments 78 // are released but which should only be initialized once (no matter 79 // how many environments are created). 80 void 81 JvmtiEnvBase::globally_initialize() { 82 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 83 assert(_globally_initialized == false, "bad call"); 84 85 JvmtiManageCapabilities::initialize(); 86 87 // register extension functions and events 88 JvmtiExtensions::register_extensions(); 89 90 #ifdef JVMTI_TRACE 91 JvmtiTrace::initialize(); 92 #endif 93 94 _globally_initialized = true; 95 } 96 97 98 void 99 JvmtiEnvBase::initialize() { 100 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 101 102 // Add this environment to the end of the environment list (order is important) 103 { 104 // This block of code must not contain any safepoints, as list deallocation 105 // (which occurs at a safepoint) cannot occur simultaneously with this list 106 // addition. Note: NoSafepointVerifier cannot, currently, be used before 107 // threads exist. 108 JvmtiEnvIterator it; 109 JvmtiEnvBase *previous_env = NULL; 110 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 111 previous_env = env; 112 } 113 if (previous_env == NULL) { 114 _head_environment = this; 115 } else { 116 previous_env->set_next_environment(this); 117 } 118 } 119 120 if (_globally_initialized == false) { 121 globally_initialize(); 122 } 123 } 124 125 jvmtiPhase 126 JvmtiEnvBase::phase() { 127 // For the JVMTI environments possessed the can_generate_early_vmstart: 128 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START 129 if (_phase == JVMTI_PHASE_PRIMORDIAL && 130 JvmtiExport::early_vmstart_recorded() && 131 early_vmstart_env()) { 132 return JVMTI_PHASE_START; 133 } 134 return _phase; // Normal case 135 } 136 137 bool 138 JvmtiEnvBase::is_valid() { 139 jint value = 0; 140 141 // This object might not be a JvmtiEnvBase so we can't assume 142 // the _magic field is properly aligned. Get the value in a safe 143 // way and then check against JVMTI_MAGIC. 144 145 switch (sizeof(_magic)) { 146 case 2: 147 value = Bytes::get_native_u2((address)&_magic); 148 break; 149 150 case 4: 151 value = Bytes::get_native_u4((address)&_magic); 152 break; 153 154 case 8: 155 value = Bytes::get_native_u8((address)&_magic); 156 break; 157 158 default: 159 guarantee(false, "_magic field is an unexpected size"); 160 } 161 162 return value == JVMTI_MAGIC; 163 } 164 165 166 bool 167 JvmtiEnvBase::use_version_1_0_semantics() { 168 int major, minor, micro; 169 170 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 171 return major == 1 && minor == 0; // micro version doesn't matter here 172 } 173 174 175 bool 176 JvmtiEnvBase::use_version_1_1_semantics() { 177 int major, minor, micro; 178 179 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 180 return major == 1 && minor == 1; // micro version doesn't matter here 181 } 182 183 bool 184 JvmtiEnvBase::use_version_1_2_semantics() { 185 int major, minor, micro; 186 187 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 188 return major == 1 && minor == 2; // micro version doesn't matter here 189 } 190 191 192 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 193 _version = version; 194 _env_local_storage = NULL; 195 _tag_map = NULL; 196 _native_method_prefix_count = 0; 197 _native_method_prefixes = NULL; 198 _next = NULL; 199 _class_file_load_hook_ever_enabled = false; 200 201 // Moot since ClassFileLoadHook not yet enabled. 202 // But "true" will give a more predictable ClassFileLoadHook behavior 203 // for environment creation during ClassFileLoadHook. 204 _is_retransformable = true; 205 206 // all callbacks initially NULL 207 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks)); 208 209 // all capabilities initially off 210 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 211 212 // all prohibited capabilities initially off 213 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 214 215 _magic = JVMTI_MAGIC; 216 217 JvmtiEventController::env_initialize((JvmtiEnv*)this); 218 219 #ifdef JVMTI_TRACE 220 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface; 221 #else 222 _jvmti_external.functions = &jvmti_Interface; 223 #endif 224 } 225 226 227 void 228 JvmtiEnvBase::dispose() { 229 230 #ifdef JVMTI_TRACE 231 JvmtiTrace::shutdown(); 232 #endif 233 234 // Dispose of event info and let the event controller call us back 235 // in a locked state (env_dispose, below) 236 JvmtiEventController::env_dispose(this); 237 } 238 239 void 240 JvmtiEnvBase::env_dispose() { 241 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 242 243 // We have been entered with all events disabled on this environment. 244 // A race to re-enable events (by setting callbacks) is prevented by 245 // checking for a valid environment when setting callbacks (while 246 // holding the JvmtiThreadState_lock). 247 248 // Mark as invalid. 249 _magic = DISPOSED_MAGIC; 250 251 // Relinquish all capabilities. 252 jvmtiCapabilities *caps = get_capabilities(); 253 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 254 255 // Same situation as with events (see above) 256 set_native_method_prefixes(0, NULL); 257 258 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 259 set_tag_map(NULL); 260 // A tag map can be big, deallocate it now 261 if (tag_map_to_deallocate != NULL) { 262 delete tag_map_to_deallocate; 263 } 264 265 _needs_clean_up = true; 266 } 267 268 269 JvmtiEnvBase::~JvmtiEnvBase() { 270 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 271 272 // There is a small window of time during which the tag map of a 273 // disposed environment could have been reallocated. 274 // Make sure it is gone. 275 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 276 set_tag_map(NULL); 277 // A tag map can be big, deallocate it now 278 if (tag_map_to_deallocate != NULL) { 279 delete tag_map_to_deallocate; 280 } 281 282 _magic = BAD_MAGIC; 283 } 284 285 286 void 287 JvmtiEnvBase::periodic_clean_up() { 288 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 289 290 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 291 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 292 JvmtiThreadState::periodic_clean_up(); 293 294 // Unlink all invalid environments from the list of environments 295 // and deallocate them 296 JvmtiEnvIterator it; 297 JvmtiEnvBase* previous_env = NULL; 298 JvmtiEnvBase* env = it.first(); 299 while (env != NULL) { 300 if (env->is_valid()) { 301 previous_env = env; 302 env = it.next(env); 303 } else { 304 // This one isn't valid, remove it from the list and deallocate it 305 JvmtiEnvBase* defunct_env = env; 306 env = it.next(env); 307 if (previous_env == NULL) { 308 _head_environment = env; 309 } else { 310 previous_env->set_next_environment(env); 311 } 312 delete defunct_env; 313 } 314 } 315 316 } 317 318 319 void 320 JvmtiEnvBase::check_for_periodic_clean_up() { 321 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 322 323 class ThreadInsideIterationClosure: public ThreadClosure { 324 private: 325 bool _inside; 326 public: 327 ThreadInsideIterationClosure() : _inside(false) {}; 328 329 void do_thread(Thread* thread) { 330 _inside |= thread->is_inside_jvmti_env_iteration(); 331 } 332 333 bool is_inside_jvmti_env_iteration() { 334 return _inside; 335 } 336 }; 337 338 if (_needs_clean_up) { 339 // Check if we are currently iterating environment, 340 // deallocation should not occur if we are 341 ThreadInsideIterationClosure tiic; 342 Threads::threads_do(&tiic); 343 if (!tiic.is_inside_jvmti_env_iteration() && 344 !is_inside_dying_thread_env_iteration()) { 345 _needs_clean_up = false; 346 JvmtiEnvBase::periodic_clean_up(); 347 } 348 } 349 } 350 351 352 void 353 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 354 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 355 "sanity check"); 356 357 if (!_class_file_load_hook_ever_enabled) { 358 _class_file_load_hook_ever_enabled = true; 359 360 if (get_capabilities()->can_retransform_classes) { 361 _is_retransformable = true; 362 } else { 363 _is_retransformable = false; 364 365 // cannot add retransform capability after ClassFileLoadHook has been enabled 366 get_prohibited_capabilities()->can_retransform_classes = 1; 367 } 368 } 369 } 370 371 372 void 373 JvmtiEnvBase::record_class_file_load_hook_enabled() { 374 if (!_class_file_load_hook_ever_enabled) { 375 if (Threads::number_of_threads() == 0) { 376 record_first_time_class_file_load_hook_enabled(); 377 } else { 378 MutexLocker mu(JvmtiThreadState_lock); 379 record_first_time_class_file_load_hook_enabled(); 380 } 381 } 382 } 383 384 385 jvmtiError 386 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 387 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 388 "sanity check"); 389 390 int old_prefix_count = get_native_method_prefix_count(); 391 char **old_prefixes = get_native_method_prefixes(); 392 393 // allocate and install the new prefixex 394 if (prefix_count == 0 || !is_valid()) { 395 _native_method_prefix_count = 0; 396 _native_method_prefixes = NULL; 397 } else { 398 // there are prefixes, allocate an array to hold them, and fill it 399 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal); 400 if (new_prefixes == NULL) { 401 return JVMTI_ERROR_OUT_OF_MEMORY; 402 } 403 for (int i = 0; i < prefix_count; i++) { 404 char* prefix = prefixes[i]; 405 if (prefix == NULL) { 406 for (int j = 0; j < (i-1); j++) { 407 os::free(new_prefixes[j]); 408 } 409 os::free(new_prefixes); 410 return JVMTI_ERROR_NULL_POINTER; 411 } 412 prefix = os::strdup(prefixes[i]); 413 if (prefix == NULL) { 414 for (int j = 0; j < (i-1); j++) { 415 os::free(new_prefixes[j]); 416 } 417 os::free(new_prefixes); 418 return JVMTI_ERROR_OUT_OF_MEMORY; 419 } 420 new_prefixes[i] = prefix; 421 } 422 _native_method_prefix_count = prefix_count; 423 _native_method_prefixes = new_prefixes; 424 } 425 426 // now that we know the new prefixes have been successfully installed we can 427 // safely remove the old ones 428 if (old_prefix_count != 0) { 429 for (int i = 0; i < old_prefix_count; i++) { 430 os::free(old_prefixes[i]); 431 } 432 os::free(old_prefixes); 433 } 434 435 return JVMTI_ERROR_NONE; 436 } 437 438 439 // Collect all the prefixes which have been set in any JVM TI environments 440 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 441 // order of environments and the order of prefixes within each environment. 442 // Return in a resource allocated array. 443 char** 444 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 445 assert(Threads::number_of_threads() == 0 || 446 SafepointSynchronize::is_at_safepoint() || 447 JvmtiThreadState_lock->is_locked(), 448 "sanity check"); 449 450 int total_count = 0; 451 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 452 453 JvmtiEnvIterator it; 454 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 455 int prefix_count = env->get_native_method_prefix_count(); 456 char** prefixes = env->get_native_method_prefixes(); 457 for (int j = 0; j < prefix_count; j++) { 458 // retrieve a prefix and so that it is safe against asynchronous changes 459 // copy it into the resource area 460 char* prefix = prefixes[j]; 461 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 462 strcpy(prefix_copy, prefix); 463 prefix_array->at_put_grow(total_count++, prefix_copy); 464 } 465 } 466 467 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 468 char** p = all_prefixes; 469 for (int i = 0; i < total_count; ++i) { 470 *p++ = prefix_array->at(i); 471 } 472 *count_ptr = total_count; 473 return all_prefixes; 474 } 475 476 void 477 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 478 jint size_of_callbacks) { 479 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 480 481 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 482 483 // clear in either case to be sure we got any gap between sizes 484 memset(&_event_callbacks, 0, byte_cnt); 485 486 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 487 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 488 // occurs after the boiler-plate environment check and before the lock is acquired. 489 if (callbacks != NULL && is_valid()) { 490 if (size_of_callbacks < (jint)byte_cnt) { 491 byte_cnt = size_of_callbacks; 492 } 493 memcpy(&_event_callbacks, callbacks, byte_cnt); 494 } 495 } 496 497 498 // In the fullness of time, all users of the method should instead 499 // directly use allocate, besides being cleaner and faster, this will 500 // mean much better out of memory handling 501 unsigned char * 502 JvmtiEnvBase::jvmtiMalloc(jlong size) { 503 unsigned char* mem = NULL; 504 jvmtiError result = allocate(size, &mem); 505 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 506 return mem; 507 } 508 509 510 // Handle management 511 512 jobject JvmtiEnvBase::jni_reference(Handle hndl) { 513 return JNIHandles::make_local(hndl()); 514 } 515 516 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) { 517 return JNIHandles::make_local(thread, hndl()); 518 } 519 520 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) { 521 JNIHandles::destroy_local(jobj); 522 } 523 524 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) { 525 JNIHandles::destroy_local(jobj); // thread is unused. 526 } 527 528 // 529 // Threads 530 // 531 532 jobject * 533 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) { 534 if (length == 0) { 535 return NULL; 536 } 537 538 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length); 539 NULL_CHECK(objArray, NULL); 540 541 for (int i=0; i<length; i++) { 542 objArray[i] = jni_reference(handles[i]); 543 } 544 return objArray; 545 } 546 547 jthread * 548 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 549 return (jthread *) new_jobjectArray(length,handles); 550 } 551 552 jthreadGroup * 553 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) { 554 return (jthreadGroup *) new_jobjectArray(length,handles); 555 } 556 557 // return the vframe on the specified thread and depth, NULL if no such frame 558 vframe* 559 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) { 560 if (!java_thread->has_last_Java_frame()) { 561 return NULL; 562 } 563 RegisterMap reg_map(java_thread); 564 vframe *vf = java_thread->last_java_vframe(®_map); 565 int d = 0; 566 while ((vf != NULL) && (d < depth)) { 567 vf = vf->java_sender(); 568 d++; 569 } 570 return vf; 571 } 572 573 574 // 575 // utilities: JNI objects 576 // 577 578 579 jclass 580 JvmtiEnvBase::get_jni_class_non_null(Klass* k) { 581 assert(k != NULL, "k != NULL"); 582 Thread *thread = Thread::current(); 583 return (jclass)jni_reference(Handle(thread, k->java_mirror())); 584 } 585 586 // 587 // Field Information 588 // 589 590 bool 591 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) { 592 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 593 return false; 594 } 595 bool found = false; 596 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 597 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 598 found = id->find_local_field(fd); 599 } else { 600 // Non-static field. The fieldID is really the offset of the field within the object. 601 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 602 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 603 } 604 return found; 605 } 606 607 // 608 // Object Monitor Information 609 // 610 611 // 612 // Count the number of objects for a lightweight monitor. The hobj 613 // parameter is object that owns the monitor so this routine will 614 // count the number of times the same object was locked by frames 615 // in java_thread. 616 // 617 jint 618 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 619 jint ret = 0; 620 if (!java_thread->has_last_Java_frame()) { 621 return ret; // no Java frames so no monitors 622 } 623 624 ResourceMark rm; 625 HandleMark hm; 626 RegisterMap reg_map(java_thread); 627 628 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL; 629 jvf = jvf->java_sender()) { 630 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 631 if (!mons->is_empty()) { 632 for (int i = 0; i < mons->length(); i++) { 633 MonitorInfo *mi = mons->at(i); 634 if (mi->owner_is_scalar_replaced()) continue; 635 636 // see if owner of the monitor is our object 637 if (mi->owner() != NULL && mi->owner() == hobj()) { 638 ret++; 639 } 640 } 641 } 642 } 643 return ret; 644 } 645 646 647 648 jvmtiError 649 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) { 650 #ifdef ASSERT 651 uint32_t debug_bits = 0; 652 #endif 653 assert((SafepointSynchronize::is_at_safepoint() || 654 java_thread->is_thread_fully_suspended(false, &debug_bits)), 655 "at safepoint or target thread is suspended"); 656 oop obj = NULL; 657 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 658 if (mon == NULL) { 659 // thread is not doing an Object.wait() call 660 mon = java_thread->current_pending_monitor(); 661 if (mon != NULL) { 662 // The thread is trying to enter() an ObjectMonitor. 663 obj = (oop)mon->object(); 664 assert(obj != NULL, "ObjectMonitor should have a valid object!"); 665 } 666 // implied else: no contended ObjectMonitor 667 } else { 668 // thread is doing an Object.wait() call 669 obj = (oop)mon->object(); 670 assert(obj != NULL, "Object.wait() should have an object"); 671 } 672 673 if (obj == NULL) { 674 *monitor_ptr = NULL; 675 } else { 676 HandleMark hm; 677 Handle hobj(Thread::current(), obj); 678 *monitor_ptr = jni_reference(calling_thread, hobj); 679 } 680 return JVMTI_ERROR_NONE; 681 } 682 683 684 jvmtiError 685 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 686 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 687 jvmtiError err = JVMTI_ERROR_NONE; 688 #ifdef ASSERT 689 uint32_t debug_bits = 0; 690 #endif 691 assert((SafepointSynchronize::is_at_safepoint() || 692 java_thread->is_thread_fully_suspended(false, &debug_bits)), 693 "at safepoint or target thread is suspended"); 694 695 if (java_thread->has_last_Java_frame()) { 696 ResourceMark rm; 697 HandleMark hm; 698 RegisterMap reg_map(java_thread); 699 700 int depth = 0; 701 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL; 702 jvf = jvf->java_sender()) { 703 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 704 // add locked objects for this frame into list 705 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1); 706 if (err != JVMTI_ERROR_NONE) { 707 return err; 708 } 709 } 710 } 711 } 712 713 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 714 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this); 715 ObjectSynchronizer::monitors_iterate(&jmc); 716 err = jmc.error(); 717 718 return err; 719 } 720 721 // Save JNI local handles for any objects that this frame owns. 722 jvmtiError 723 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread, 724 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) { 725 jvmtiError err = JVMTI_ERROR_NONE; 726 ResourceMark rm; 727 728 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 729 if (mons->is_empty()) { 730 return err; // this javaVFrame holds no monitors 731 } 732 733 HandleMark hm; 734 oop wait_obj = NULL; 735 { 736 // save object of current wait() call (if any) for later comparison 737 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 738 if (mon != NULL) { 739 wait_obj = (oop)mon->object(); 740 } 741 } 742 oop pending_obj = NULL; 743 { 744 // save object of current enter() call (if any) for later comparison 745 ObjectMonitor *mon = java_thread->current_pending_monitor(); 746 if (mon != NULL) { 747 pending_obj = (oop)mon->object(); 748 } 749 } 750 751 for (int i = 0; i < mons->length(); i++) { 752 MonitorInfo *mi = mons->at(i); 753 754 if (mi->owner_is_scalar_replaced()) continue; 755 756 oop obj = mi->owner(); 757 if (obj == NULL) { 758 // this monitor doesn't have an owning object so skip it 759 continue; 760 } 761 762 if (wait_obj == obj) { 763 // the thread is waiting on this monitor so it isn't really owned 764 continue; 765 } 766 767 if (pending_obj == obj) { 768 // the thread is pending on this monitor so it isn't really owned 769 continue; 770 } 771 772 if (owned_monitors_list->length() > 0) { 773 // Our list has at least one object on it so we have to check 774 // for recursive object locking 775 bool found = false; 776 for (int j = 0; j < owned_monitors_list->length(); j++) { 777 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 778 oop check = JNIHandles::resolve(jobj); 779 if (check == obj) { 780 found = true; // we found the object 781 break; 782 } 783 } 784 785 if (found) { 786 // already have this object so don't include it 787 continue; 788 } 789 } 790 791 // add the owning object to our list 792 jvmtiMonitorStackDepthInfo *jmsdi; 793 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 794 if (err != JVMTI_ERROR_NONE) { 795 return err; 796 } 797 Handle hobj(Thread::current(), obj); 798 jmsdi->monitor = jni_reference(calling_thread, hobj); 799 jmsdi->stack_depth = stack_depth; 800 owned_monitors_list->append(jmsdi); 801 } 802 803 return err; 804 } 805 806 jvmtiError 807 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 808 jint start_depth, jint max_count, 809 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 810 #ifdef ASSERT 811 uint32_t debug_bits = 0; 812 #endif 813 assert((SafepointSynchronize::is_at_safepoint() || 814 java_thread->is_thread_fully_suspended(false, &debug_bits)), 815 "at safepoint or target thread is suspended"); 816 int count = 0; 817 if (java_thread->has_last_Java_frame()) { 818 RegisterMap reg_map(java_thread); 819 Thread* current_thread = Thread::current(); 820 ResourceMark rm(current_thread); 821 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 822 HandleMark hm(current_thread); 823 if (start_depth != 0) { 824 if (start_depth > 0) { 825 for (int j = 0; j < start_depth && jvf != NULL; j++) { 826 jvf = jvf->java_sender(); 827 } 828 if (jvf == NULL) { 829 // start_depth is deeper than the stack depth 830 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 831 } 832 } else { // start_depth < 0 833 // we are referencing the starting depth based on the oldest 834 // part of the stack. 835 // optimize to limit the number of times that java_sender() is called 836 javaVFrame *jvf_cursor = jvf; 837 javaVFrame *jvf_prev = NULL; 838 javaVFrame *jvf_prev_prev = NULL; 839 int j = 0; 840 while (jvf_cursor != NULL) { 841 jvf_prev_prev = jvf_prev; 842 jvf_prev = jvf_cursor; 843 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) { 844 jvf_cursor = jvf_cursor->java_sender(); 845 } 846 } 847 if (j == start_depth) { 848 // previous pointer is exactly where we want to start 849 jvf = jvf_prev; 850 } else { 851 // we need to back up further to get to the right place 852 if (jvf_prev_prev == NULL) { 853 // the -start_depth is greater than the stack depth 854 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 855 } 856 // j now is the number of frames on the stack starting with 857 // jvf_prev, we start from jvf_prev_prev and move older on 858 // the stack that many, the result is -start_depth frames 859 // remaining. 860 jvf = jvf_prev_prev; 861 for (; j < 0; j++) { 862 jvf = jvf->java_sender(); 863 } 864 } 865 } 866 } 867 for (; count < max_count && jvf != NULL; count++) { 868 frame_buffer[count].method = jvf->method()->jmethod_id(); 869 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 870 jvf = jvf->java_sender(); 871 } 872 } else { 873 if (start_depth != 0) { 874 // no frames and there is a starting depth 875 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 876 } 877 } 878 *count_ptr = count; 879 return JVMTI_ERROR_NONE; 880 } 881 882 jvmtiError 883 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) { 884 assert((state != NULL), 885 "JavaThread should create JvmtiThreadState before calling this method"); 886 *count_ptr = state->count_frames(); 887 return JVMTI_ERROR_NONE; 888 } 889 890 jvmtiError 891 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 892 jmethodID* method_ptr, jlocation* location_ptr) { 893 #ifdef ASSERT 894 uint32_t debug_bits = 0; 895 #endif 896 assert((SafepointSynchronize::is_at_safepoint() || 897 java_thread->is_thread_fully_suspended(false, &debug_bits)), 898 "at safepoint or target thread is suspended"); 899 Thread* current_thread = Thread::current(); 900 ResourceMark rm(current_thread); 901 902 vframe *vf = vframeFor(java_thread, depth); 903 if (vf == NULL) { 904 return JVMTI_ERROR_NO_MORE_FRAMES; 905 } 906 907 // vframeFor should return a java frame. If it doesn't 908 // it means we've got an internal error and we return the 909 // error in product mode. In debug mode we will instead 910 // attempt to cast the vframe to a javaVFrame and will 911 // cause an assertion/crash to allow further diagnosis. 912 #ifdef PRODUCT 913 if (!vf->is_java_frame()) { 914 return JVMTI_ERROR_INTERNAL; 915 } 916 #endif 917 918 HandleMark hm(current_thread); 919 javaVFrame *jvf = javaVFrame::cast(vf); 920 Method* method = jvf->method(); 921 if (method->is_native()) { 922 *location_ptr = -1; 923 } else { 924 *location_ptr = jvf->bci(); 925 } 926 *method_ptr = method->jmethod_id(); 927 928 return JVMTI_ERROR_NONE; 929 } 930 931 932 jvmtiError 933 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 934 HandleMark hm; 935 Handle hobj; 936 937 Thread* current_thread = Thread::current(); 938 bool at_safepoint = SafepointSynchronize::is_at_safepoint(); 939 940 // Check arguments 941 { 942 oop mirror = JNIHandles::resolve_external_guard(object); 943 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 944 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 945 946 hobj = Handle(current_thread, mirror); 947 } 948 949 JavaThread *owning_thread = NULL; 950 ObjectMonitor *mon = NULL; 951 jvmtiMonitorUsage ret = { 952 NULL, 0, 0, NULL, 0, NULL 953 }; 954 955 uint32_t debug_bits = 0; 956 // first derive the object's owner and entry_count (if any) 957 { 958 // Revoke any biases before querying the mark word 959 if (at_safepoint) { 960 BiasedLocking::revoke_at_safepoint(hobj); 961 } else { 962 BiasedLocking::revoke(hobj, calling_thread); 963 } 964 965 address owner = NULL; 966 { 967 markWord mark = hobj()->mark(); 968 969 if (!mark.has_monitor()) { 970 // this object has a lightweight monitor 971 972 if (mark.has_locker()) { 973 owner = (address)mark.locker(); // save the address of the Lock word 974 } 975 // implied else: no owner 976 } else { 977 // this object has a heavyweight monitor 978 mon = mark.monitor(); 979 980 // The owner field of a heavyweight monitor may be NULL for no 981 // owner, a JavaThread * or it may still be the address of the 982 // Lock word in a JavaThread's stack. A monitor can be inflated 983 // by a non-owning JavaThread, but only the owning JavaThread 984 // can change the owner field from the Lock word to the 985 // JavaThread * and it may not have done that yet. 986 owner = (address)mon->owner(); 987 } 988 } 989 990 if (owner != NULL) { 991 // Use current thread since function can be called from a 992 // JavaThread or the VMThread. 993 ThreadsListHandle tlh; 994 // This monitor is owned so we have to find the owning JavaThread. 995 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner); 996 // Cannot assume (owning_thread != NULL) here because this function 997 // may not have been called at a safepoint and the owning_thread 998 // might not be suspended. 999 if (owning_thread != NULL) { 1000 // The monitor's owner either has to be the current thread, at safepoint 1001 // or it has to be suspended. Any of these conditions will prevent both 1002 // contending and waiting threads from modifying the state of 1003 // the monitor. 1004 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) { 1005 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED 1006 // will not make it back to the JVM/TI agent. The error code will 1007 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which 1008 // will retry the call via a VM_GetObjectMonitorUsage VM op. 1009 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1010 } 1011 HandleMark hm; 1012 Handle th(current_thread, owning_thread->threadObj()); 1013 ret.owner = (jthread)jni_reference(calling_thread, th); 1014 } 1015 // implied else: no owner 1016 } // ThreadsListHandle is destroyed here. 1017 1018 if (owning_thread != NULL) { // monitor is owned 1019 // The recursions field of a monitor does not reflect recursions 1020 // as lightweight locks before inflating the monitor are not included. 1021 // We have to count the number of recursive monitor entries the hard way. 1022 // We pass a handle to survive any GCs along the way. 1023 ResourceMark rm; 1024 ret.entry_count = count_locked_objects(owning_thread, hobj); 1025 } 1026 // implied else: entry_count == 0 1027 } 1028 1029 jint nWant = 0, nWait = 0; 1030 if (mon != NULL) { 1031 // this object has a heavyweight monitor 1032 nWant = mon->contentions(); // # of threads contending for monitor 1033 nWait = mon->waiters(); // # of threads in Object.wait() 1034 ret.waiter_count = nWant + nWait; 1035 ret.notify_waiter_count = nWait; 1036 } else { 1037 // this object has a lightweight monitor 1038 ret.waiter_count = 0; 1039 ret.notify_waiter_count = 0; 1040 } 1041 1042 // Allocate memory for heavyweight and lightweight monitor. 1043 jvmtiError err; 1044 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1045 if (err != JVMTI_ERROR_NONE) { 1046 return err; 1047 } 1048 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1049 (unsigned char**)&ret.notify_waiters); 1050 if (err != JVMTI_ERROR_NONE) { 1051 deallocate((unsigned char*)ret.waiters); 1052 return err; 1053 } 1054 1055 // now derive the rest of the fields 1056 if (mon != NULL) { 1057 // this object has a heavyweight monitor 1058 1059 // Number of waiters may actually be less than the waiter count. 1060 // So NULL out memory so that unused memory will be NULL. 1061 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1062 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1063 1064 if (ret.waiter_count > 0) { 1065 // we have contending and/or waiting threads 1066 HandleMark hm; 1067 // Use current thread since function can be called from a 1068 // JavaThread or the VMThread. 1069 ThreadsListHandle tlh; 1070 if (nWant > 0) { 1071 // we have contending threads 1072 ResourceMark rm; 1073 // get_pending_threads returns only java thread so we do not need to 1074 // check for non java threads. 1075 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon); 1076 if (wantList->length() < nWant) { 1077 // robustness: the pending list has gotten smaller 1078 nWant = wantList->length(); 1079 } 1080 for (int i = 0; i < nWant; i++) { 1081 JavaThread *pending_thread = wantList->at(i); 1082 // If the monitor has no owner, then a non-suspended contending 1083 // thread could potentially change the state of the monitor by 1084 // entering it. The JVM/TI spec doesn't allow this. 1085 if (owning_thread == NULL && !at_safepoint && 1086 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) { 1087 if (ret.owner != NULL) { 1088 destroy_jni_reference(calling_thread, ret.owner); 1089 } 1090 for (int j = 0; j < i; j++) { 1091 destroy_jni_reference(calling_thread, ret.waiters[j]); 1092 } 1093 deallocate((unsigned char*)ret.waiters); 1094 deallocate((unsigned char*)ret.notify_waiters); 1095 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1096 } 1097 Handle th(current_thread, pending_thread->threadObj()); 1098 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1099 } 1100 } 1101 if (nWait > 0) { 1102 // we have threads in Object.wait() 1103 int offset = nWant; // add after any contending threads 1104 ObjectWaiter *waiter = mon->first_waiter(); 1105 for (int i = 0, j = 0; i < nWait; i++) { 1106 if (waiter == NULL) { 1107 // robustness: the waiting list has gotten smaller 1108 nWait = j; 1109 break; 1110 } 1111 Thread *t = mon->thread_of_waiter(waiter); 1112 if (t != NULL && t->is_Java_thread()) { 1113 JavaThread *wjava_thread = (JavaThread *)t; 1114 // If the thread was found on the ObjectWaiter list, then 1115 // it has not been notified. This thread can't change the 1116 // state of the monitor so it doesn't need to be suspended. 1117 Handle th(current_thread, wjava_thread->threadObj()); 1118 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th); 1119 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th); 1120 } 1121 waiter = mon->next_waiter(waiter); 1122 } 1123 } 1124 } // ThreadsListHandle is destroyed here. 1125 1126 // Adjust count. nWant and nWait count values may be less than original. 1127 ret.waiter_count = nWant + nWait; 1128 ret.notify_waiter_count = nWait; 1129 } else { 1130 // this object has a lightweight monitor and we have nothing more 1131 // to do here because the defaults are just fine. 1132 } 1133 1134 // we don't update return parameter unless everything worked 1135 *info_ptr = ret; 1136 1137 return JVMTI_ERROR_NONE; 1138 } 1139 1140 ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1141 _env = env; 1142 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true); 1143 _failed = false; 1144 } 1145 ResourceTracker::~ResourceTracker() { 1146 if (_failed) { 1147 for (int i=0; i<_allocations->length(); i++) { 1148 _env->deallocate(_allocations->at(i)); 1149 } 1150 } 1151 delete _allocations; 1152 } 1153 1154 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1155 unsigned char *ptr; 1156 jvmtiError err = _env->allocate(size, &ptr); 1157 if (err == JVMTI_ERROR_NONE) { 1158 _allocations->append(ptr); 1159 *mem_ptr = ptr; 1160 } else { 1161 *mem_ptr = NULL; 1162 _failed = true; 1163 } 1164 return err; 1165 } 1166 1167 unsigned char* ResourceTracker::allocate(jlong size) { 1168 unsigned char* ptr; 1169 allocate(size, &ptr); 1170 return ptr; 1171 } 1172 1173 char* ResourceTracker::strdup(const char* str) { 1174 char *dup_str = (char*)allocate(strlen(str)+1); 1175 if (dup_str != NULL) { 1176 strcpy(dup_str, str); 1177 } 1178 return dup_str; 1179 } 1180 1181 struct StackInfoNode { 1182 struct StackInfoNode *next; 1183 jvmtiStackInfo info; 1184 }; 1185 1186 // Create a jvmtiStackInfo inside a linked list node and create a 1187 // buffer for the frame information, both allocated as resource objects. 1188 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1189 // Note that either or both of thr and thread_oop 1190 // may be null if the thread is new or has exited. 1191 void 1192 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1193 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1194 1195 jint state = 0; 1196 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1197 jvmtiStackInfo *infop = &(node->info); 1198 node->next = head(); 1199 set_head(node); 1200 infop->frame_count = 0; 1201 infop->thread = jt; 1202 1203 if (thread_oop != NULL) { 1204 // get most state bits 1205 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 1206 } 1207 1208 if (thr != NULL) { // add more state bits if there is a JavaThead to query 1209 // same as is_being_ext_suspended() but without locking 1210 if (thr->is_ext_suspended() || thr->is_external_suspend()) { 1211 state |= JVMTI_THREAD_STATE_SUSPENDED; 1212 } 1213 JavaThreadState jts = thr->thread_state(); 1214 if (jts == _thread_in_native) { 1215 state |= JVMTI_THREAD_STATE_IN_NATIVE; 1216 } 1217 OSThread* osThread = thr->osthread(); 1218 if (osThread != NULL && osThread->interrupted()) { 1219 state |= JVMTI_THREAD_STATE_INTERRUPTED; 1220 } 1221 } 1222 infop->state = state; 1223 1224 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1225 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1226 env()->get_stack_trace(thr, 0, max_frame_count(), 1227 infop->frame_buffer, &(infop->frame_count)); 1228 } else { 1229 infop->frame_buffer = NULL; 1230 infop->frame_count = 0; 1231 } 1232 _frame_count_total += infop->frame_count; 1233 } 1234 1235 // Based on the stack information in the linked list, allocate memory 1236 // block to return and fill it from the info in the linked list. 1237 void 1238 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) { 1239 // do I need to worry about alignment issues? 1240 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1241 + _frame_count_total * sizeof(jvmtiFrameInfo); 1242 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1243 1244 // pointers to move through the newly allocated space as it is filled in 1245 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1246 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1247 1248 // copy information in resource area into allocated buffer 1249 // insert stack info backwards since linked list is backwards 1250 // insert frame info forwards 1251 // walk the StackInfoNodes 1252 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) { 1253 jint frame_count = sin->info.frame_count; 1254 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1255 --si; 1256 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1257 if (frames_size == 0) { 1258 si->frame_buffer = NULL; 1259 } else { 1260 memcpy(fi, sin->info.frame_buffer, frames_size); 1261 si->frame_buffer = fi; // point to the new allocated copy of the frames 1262 fi += frame_count; 1263 } 1264 } 1265 assert(si == _stack_info, "the last copied stack info must be the first record"); 1266 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1267 "the last copied frame info must be the last record"); 1268 } 1269 1270 1271 void 1272 VM_GetThreadListStackTraces::doit() { 1273 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1274 1275 ResourceMark rm; 1276 ThreadsListHandle tlh; 1277 for (int i = 0; i < _thread_count; ++i) { 1278 jthread jt = _thread_list[i]; 1279 JavaThread* java_thread = NULL; 1280 oop thread_oop = NULL; 1281 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop); 1282 if (err != JVMTI_ERROR_NONE) { 1283 // We got an error code so we don't have a JavaThread *, but 1284 // only return an error from here if we didn't get a valid 1285 // thread_oop. 1286 if (thread_oop == NULL) { 1287 set_result(err); 1288 return; 1289 } 1290 // We have a valid thread_oop. 1291 } 1292 fill_frames(jt, java_thread, thread_oop); 1293 } 1294 allocate_and_fill_stacks(_thread_count); 1295 } 1296 1297 void 1298 VM_GetAllStackTraces::doit() { 1299 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1300 1301 ResourceMark rm; 1302 _final_thread_count = 0; 1303 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1304 oop thread_oop = jt->threadObj(); 1305 if (thread_oop != NULL && 1306 !jt->is_exiting() && 1307 java_lang_Thread::is_alive(thread_oop) && 1308 !jt->is_hidden_from_external_view()) { 1309 ++_final_thread_count; 1310 // Handle block of the calling thread is used to create local refs. 1311 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1312 jt, thread_oop); 1313 } 1314 } 1315 allocate_and_fill_stacks(_final_thread_count); 1316 } 1317 1318 // Verifies that the top frame is a java frame in an expected state. 1319 // Deoptimizes frame if needed. 1320 // Checks that the frame method signature matches the return type (tos). 1321 // HandleMark must be defined in the caller only. 1322 // It is to keep a ret_ob_h handle alive after return to the caller. 1323 jvmtiError 1324 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread, 1325 jvalue value, TosState tos, Handle* ret_ob_h) { 1326 ResourceMark rm(current_thread); 1327 1328 vframe *vf = vframeFor(java_thread, 0); 1329 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES); 1330 1331 javaVFrame *jvf = (javaVFrame*) vf; 1332 if (!vf->is_java_frame() || jvf->method()->is_native()) { 1333 return JVMTI_ERROR_OPAQUE_FRAME; 1334 } 1335 1336 // If the frame is a compiled one, need to deoptimize it. 1337 if (vf->is_compiled_frame()) { 1338 if (!vf->fr().can_be_deoptimized()) { 1339 return JVMTI_ERROR_OPAQUE_FRAME; 1340 } 1341 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 1342 } 1343 1344 // Get information about method return type 1345 Symbol* signature = jvf->method()->signature(); 1346 1347 ResultTypeFinder rtf(signature); 1348 TosState fr_tos = as_TosState(rtf.type()); 1349 if (fr_tos != tos) { 1350 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) { 1351 return JVMTI_ERROR_TYPE_MISMATCH; 1352 } 1353 } 1354 1355 // Check that the jobject class matches the return type signature. 1356 jobject jobj = value.l; 1357 if (tos == atos && jobj != NULL) { // NULL reference is allowed 1358 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj)); 1359 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 1360 Klass* ob_k = ob_h()->klass(); 1361 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT); 1362 1363 // Method return type signature. 1364 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC); 1365 1366 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) { 1367 return JVMTI_ERROR_TYPE_MISMATCH; 1368 } 1369 *ret_ob_h = ob_h; 1370 } 1371 return JVMTI_ERROR_NONE; 1372 } /* end check_top_frame */ 1373 1374 1375 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 1376 // Main difference is on the last stage in the interpreter. 1377 // The PopFrame stops method execution to continue execution 1378 // from the same method call instruction. 1379 // The ForceEarlyReturn forces return from method so the execution 1380 // continues at the bytecode following the method call. 1381 1382 // Threads_lock NOT held, java_thread not protected by lock 1383 // java_thread - pre-checked 1384 1385 jvmtiError 1386 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) { 1387 JavaThread* current_thread = JavaThread::current(); 1388 HandleMark hm(current_thread); 1389 uint32_t debug_bits = 0; 1390 1391 // retrieve or create the state 1392 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 1393 if (state == NULL) { 1394 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1395 } 1396 1397 // Check if java_thread is fully suspended 1398 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) { 1399 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1400 } 1401 1402 // Check to see if a ForceEarlyReturn was already in progress 1403 if (state->is_earlyret_pending()) { 1404 // Probably possible for JVMTI clients to trigger this, but the 1405 // JPDA backend shouldn't allow this to happen 1406 return JVMTI_ERROR_INTERNAL; 1407 } 1408 { 1409 // The same as for PopFrame. Workaround bug: 1410 // 4812902: popFrame hangs if the method is waiting at a synchronize 1411 // Catch this condition and return an error to avoid hanging. 1412 // Now JVMTI spec allows an implementation to bail out with an opaque 1413 // frame error. 1414 OSThread* osThread = java_thread->osthread(); 1415 if (osThread->get_state() == MONITOR_WAIT) { 1416 return JVMTI_ERROR_OPAQUE_FRAME; 1417 } 1418 } 1419 Handle ret_ob_h; 1420 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h); 1421 if (err != JVMTI_ERROR_NONE) { 1422 return err; 1423 } 1424 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL, 1425 "return object oop must not be NULL if jobject is not NULL"); 1426 1427 // Update the thread state to reflect that the top frame must be 1428 // forced to return. 1429 // The current frame will be returned later when the suspended 1430 // thread is resumed and right before returning from VM to Java. 1431 // (see call_VM_base() in assembler_<cpu>.cpp). 1432 1433 state->set_earlyret_pending(); 1434 state->set_earlyret_oop(ret_ob_h()); 1435 state->set_earlyret_value(value, tos); 1436 1437 // Set pending step flag for this early return. 1438 // It is cleared when next step event is posted. 1439 state->set_pending_step_for_earlyret(); 1440 1441 return JVMTI_ERROR_NONE; 1442 } /* end force_early_return */ 1443 1444 void 1445 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 1446 if ( _error != JVMTI_ERROR_NONE) { 1447 // Error occurred in previous iteration so no need to add 1448 // to the list. 1449 return; 1450 } 1451 if (mon->owner() == _java_thread ) { 1452 // Filter out on stack monitors collected during stack walk. 1453 oop obj = (oop)mon->object(); 1454 bool found = false; 1455 for (int j = 0; j < _owned_monitors_list->length(); j++) { 1456 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 1457 oop check = JNIHandles::resolve(jobj); 1458 if (check == obj) { 1459 // On stack monitor already collected during the stack walk. 1460 found = true; 1461 break; 1462 } 1463 } 1464 if (found == false) { 1465 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 1466 jvmtiError err; 1467 jvmtiMonitorStackDepthInfo *jmsdi; 1468 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1469 if (err != JVMTI_ERROR_NONE) { 1470 _error = err; 1471 return; 1472 } 1473 Handle hobj(Thread::current(), obj); 1474 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 1475 // stack depth is unknown for this monitor. 1476 jmsdi->stack_depth = -1; 1477 _owned_monitors_list->append(jmsdi); 1478 } 1479 } 1480 } 1481 1482 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL; 1483 1484 void JvmtiModuleClosure::do_module(ModuleEntry* entry) { 1485 assert_locked_or_safepoint(Module_lock); 1486 OopHandle module = entry->module_handle(); 1487 guarantee(module.resolve() != NULL, "module object is NULL"); 1488 _tbl->push(module); 1489 } 1490 1491 jvmtiError 1492 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) { 1493 ResourceMark rm; 1494 MutexLocker mcld(ClassLoaderDataGraph_lock); 1495 MutexLocker ml(Module_lock); 1496 1497 _tbl = new GrowableArray<OopHandle>(77); 1498 if (_tbl == NULL) { 1499 return JVMTI_ERROR_OUT_OF_MEMORY; 1500 } 1501 1502 // Iterate over all the modules loaded to the system. 1503 ClassLoaderDataGraph::modules_do(&do_module); 1504 1505 jint len = _tbl->length(); 1506 guarantee(len > 0, "at least one module must be present"); 1507 1508 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject))); 1509 if (array == NULL) { 1510 return JVMTI_ERROR_OUT_OF_MEMORY; 1511 } 1512 for (jint idx = 0; idx < len; idx++) { 1513 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve()); 1514 } 1515 _tbl = NULL; 1516 *modules_ptr = array; 1517 *module_count_ptr = len; 1518 return JVMTI_ERROR_NONE; 1519 } 1520 1521 void 1522 VM_UpdateForPopTopFrame::doit() { 1523 JavaThread* jt = _state->get_thread(); 1524 ThreadsListHandle tlh; 1525 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1526 _state->update_for_pop_top_frame(); 1527 } else { 1528 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1529 } 1530 } 1531 1532 void 1533 VM_SetFramePop::doit() { 1534 JavaThread* jt = _state->get_thread(); 1535 ThreadsListHandle tlh; 1536 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1537 int frame_number = _state->count_frames() - _depth; 1538 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number); 1539 } else { 1540 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1541 } 1542 } 1543 1544 void 1545 VM_GetOwnedMonitorInfo::doit() { 1546 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1547 ThreadsListHandle tlh; 1548 if (_java_thread != NULL && tlh.includes(_java_thread) 1549 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1550 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread, 1551 _owned_monitors_list); 1552 } 1553 } 1554 1555 void 1556 VM_GetCurrentContendedMonitor::doit() { 1557 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1558 ThreadsListHandle tlh; 1559 if (_java_thread != NULL && tlh.includes(_java_thread) 1560 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1561 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr); 1562 } 1563 } 1564 1565 void 1566 VM_GetStackTrace::doit() { 1567 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1568 ThreadsListHandle tlh; 1569 if (_java_thread != NULL && tlh.includes(_java_thread) 1570 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1571 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread, 1572 _start_depth, _max_count, 1573 _frame_buffer, _count_ptr); 1574 } 1575 } 1576 1577 void 1578 VM_GetFrameCount::doit() { 1579 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1580 JavaThread* jt = _state->get_thread(); 1581 ThreadsListHandle tlh; 1582 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1583 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr); 1584 } 1585 } 1586 1587 void 1588 VM_GetFrameLocation::doit() { 1589 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1590 ThreadsListHandle tlh; 1591 if (_java_thread != NULL && tlh.includes(_java_thread) 1592 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1593 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth, 1594 _method_ptr, _location_ptr); 1595 } 1596 }