1 /* 2 * Copyright (c) 2003, 2020, 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/iterator.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "oops/objArrayKlass.hpp" 33 #include "oops/objArrayOop.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "oops/oopHandle.inline.hpp" 36 #include "prims/jvmtiEnvBase.hpp" 37 #include "prims/jvmtiEventController.inline.hpp" 38 #include "prims/jvmtiExtensions.hpp" 39 #include "prims/jvmtiImpl.hpp" 40 #include "prims/jvmtiManageCapabilities.hpp" 41 #include "prims/jvmtiTagMap.hpp" 42 #include "prims/jvmtiThreadState.inline.hpp" 43 #include "runtime/biasedLocking.hpp" 44 #include "runtime/deoptimization.hpp" 45 #include "runtime/frame.inline.hpp" 46 #include "runtime/handles.inline.hpp" 47 #include "runtime/interfaceSupport.inline.hpp" 48 #include "runtime/jfieldIDWorkaround.hpp" 49 #include "runtime/jniHandles.inline.hpp" 50 #include "runtime/objectMonitor.hpp" 51 #include "runtime/objectMonitor.inline.hpp" 52 #include "runtime/signature.hpp" 53 #include "runtime/thread.inline.hpp" 54 #include "runtime/threadSMR.hpp" 55 #include "runtime/vframe.hpp" 56 #include "runtime/vframe_hp.hpp" 57 #include "runtime/vmThread.hpp" 58 #include "runtime/vmOperations.hpp" 59 60 /////////////////////////////////////////////////////////////// 61 // 62 // JvmtiEnvBase 63 // 64 65 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL; 66 67 bool JvmtiEnvBase::_globally_initialized = false; 68 volatile bool JvmtiEnvBase::_needs_clean_up = false; 69 70 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 71 72 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 73 74 extern jvmtiInterface_1_ jvmti_Interface; 75 extern jvmtiInterface_1_ jvmtiTrace_Interface; 76 77 78 // perform initializations that must occur before any JVMTI environments 79 // are released but which should only be initialized once (no matter 80 // how many environments are created). 81 void 82 JvmtiEnvBase::globally_initialize() { 83 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 84 assert(_globally_initialized == false, "bad call"); 85 86 JvmtiManageCapabilities::initialize(); 87 88 // register extension functions and events 89 JvmtiExtensions::register_extensions(); 90 91 #ifdef JVMTI_TRACE 92 JvmtiTrace::initialize(); 93 #endif 94 95 _globally_initialized = true; 96 } 97 98 99 void 100 JvmtiEnvBase::initialize() { 101 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 102 103 // Add this environment to the end of the environment list (order is important) 104 { 105 // This block of code must not contain any safepoints, as list deallocation 106 // (which occurs at a safepoint) cannot occur simultaneously with this list 107 // addition. Note: NoSafepointVerifier cannot, currently, be used before 108 // threads exist. 109 JvmtiEnvIterator it; 110 JvmtiEnvBase *previous_env = NULL; 111 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 112 previous_env = env; 113 } 114 if (previous_env == NULL) { 115 _head_environment = this; 116 } else { 117 previous_env->set_next_environment(this); 118 } 119 } 120 121 if (_globally_initialized == false) { 122 globally_initialize(); 123 } 124 } 125 126 jvmtiPhase 127 JvmtiEnvBase::phase() { 128 // For the JVMTI environments possessed the can_generate_early_vmstart: 129 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START 130 if (_phase == JVMTI_PHASE_PRIMORDIAL && 131 JvmtiExport::early_vmstart_recorded() && 132 early_vmstart_env()) { 133 return JVMTI_PHASE_START; 134 } 135 return _phase; // Normal case 136 } 137 138 bool 139 JvmtiEnvBase::is_valid() { 140 jint value = 0; 141 142 // This object might not be a JvmtiEnvBase so we can't assume 143 // the _magic field is properly aligned. Get the value in a safe 144 // way and then check against JVMTI_MAGIC. 145 146 switch (sizeof(_magic)) { 147 case 2: 148 value = Bytes::get_native_u2((address)&_magic); 149 break; 150 151 case 4: 152 value = Bytes::get_native_u4((address)&_magic); 153 break; 154 155 case 8: 156 value = Bytes::get_native_u8((address)&_magic); 157 break; 158 159 default: 160 guarantee(false, "_magic field is an unexpected size"); 161 } 162 163 return value == JVMTI_MAGIC; 164 } 165 166 167 bool 168 JvmtiEnvBase::use_version_1_0_semantics() { 169 int major, minor, micro; 170 171 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 172 return major == 1 && minor == 0; // micro version doesn't matter here 173 } 174 175 176 bool 177 JvmtiEnvBase::use_version_1_1_semantics() { 178 int major, minor, micro; 179 180 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 181 return major == 1 && minor == 1; // micro version doesn't matter here 182 } 183 184 bool 185 JvmtiEnvBase::use_version_1_2_semantics() { 186 int major, minor, micro; 187 188 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 189 return major == 1 && minor == 2; // micro version doesn't matter here 190 } 191 192 193 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 194 _version = version; 195 _env_local_storage = NULL; 196 _tag_map = NULL; 197 _native_method_prefix_count = 0; 198 _native_method_prefixes = NULL; 199 _next = NULL; 200 _class_file_load_hook_ever_enabled = false; 201 202 // Moot since ClassFileLoadHook not yet enabled. 203 // But "true" will give a more predictable ClassFileLoadHook behavior 204 // for environment creation during ClassFileLoadHook. 205 _is_retransformable = true; 206 207 // all callbacks initially NULL 208 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks)); 209 210 // all capabilities initially off 211 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 212 213 // all prohibited capabilities initially off 214 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 215 216 _magic = JVMTI_MAGIC; 217 218 JvmtiEventController::env_initialize((JvmtiEnv*)this); 219 220 #ifdef JVMTI_TRACE 221 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface; 222 #else 223 _jvmti_external.functions = &jvmti_Interface; 224 #endif 225 } 226 227 228 void 229 JvmtiEnvBase::dispose() { 230 231 #ifdef JVMTI_TRACE 232 JvmtiTrace::shutdown(); 233 #endif 234 235 // Dispose of event info and let the event controller call us back 236 // in a locked state (env_dispose, below) 237 JvmtiEventController::env_dispose(this); 238 } 239 240 void 241 JvmtiEnvBase::env_dispose() { 242 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 243 244 // We have been entered with all events disabled on this environment. 245 // A race to re-enable events (by setting callbacks) is prevented by 246 // checking for a valid environment when setting callbacks (while 247 // holding the JvmtiThreadState_lock). 248 249 // Mark as invalid. 250 _magic = DISPOSED_MAGIC; 251 252 // Relinquish all capabilities. 253 jvmtiCapabilities *caps = get_capabilities(); 254 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 255 256 // Same situation as with events (see above) 257 set_native_method_prefixes(0, NULL); 258 259 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 260 set_tag_map(NULL); 261 // A tag map can be big, deallocate it now 262 if (tag_map_to_deallocate != NULL) { 263 delete tag_map_to_deallocate; 264 } 265 266 _needs_clean_up = true; 267 } 268 269 270 JvmtiEnvBase::~JvmtiEnvBase() { 271 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 272 273 // There is a small window of time during which the tag map of a 274 // disposed environment could have been reallocated. 275 // Make sure it is gone. 276 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 277 set_tag_map(NULL); 278 // A tag map can be big, deallocate it now 279 if (tag_map_to_deallocate != NULL) { 280 delete tag_map_to_deallocate; 281 } 282 283 _magic = BAD_MAGIC; 284 } 285 286 287 void 288 JvmtiEnvBase::periodic_clean_up() { 289 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 290 291 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 292 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 293 JvmtiThreadState::periodic_clean_up(); 294 295 // Unlink all invalid environments from the list of environments 296 // and deallocate them 297 JvmtiEnvIterator it; 298 JvmtiEnvBase* previous_env = NULL; 299 JvmtiEnvBase* env = it.first(); 300 while (env != NULL) { 301 if (env->is_valid()) { 302 previous_env = env; 303 env = it.next(env); 304 } else { 305 // This one isn't valid, remove it from the list and deallocate it 306 JvmtiEnvBase* defunct_env = env; 307 env = it.next(env); 308 if (previous_env == NULL) { 309 _head_environment = env; 310 } else { 311 previous_env->set_next_environment(env); 312 } 313 delete defunct_env; 314 } 315 } 316 317 } 318 319 320 void 321 JvmtiEnvBase::check_for_periodic_clean_up() { 322 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 323 324 class ThreadInsideIterationClosure: public ThreadClosure { 325 private: 326 bool _inside; 327 public: 328 ThreadInsideIterationClosure() : _inside(false) {}; 329 330 void do_thread(Thread* thread) { 331 _inside |= thread->is_inside_jvmti_env_iteration(); 332 } 333 334 bool is_inside_jvmti_env_iteration() { 335 return _inside; 336 } 337 }; 338 339 if (_needs_clean_up) { 340 // Check if we are currently iterating environment, 341 // deallocation should not occur if we are 342 ThreadInsideIterationClosure tiic; 343 Threads::threads_do(&tiic); 344 if (!tiic.is_inside_jvmti_env_iteration() && 345 !is_inside_dying_thread_env_iteration()) { 346 _needs_clean_up = false; 347 JvmtiEnvBase::periodic_clean_up(); 348 } 349 } 350 } 351 352 353 void 354 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 355 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 356 "sanity check"); 357 358 if (!_class_file_load_hook_ever_enabled) { 359 _class_file_load_hook_ever_enabled = true; 360 361 if (get_capabilities()->can_retransform_classes) { 362 _is_retransformable = true; 363 } else { 364 _is_retransformable = false; 365 366 // cannot add retransform capability after ClassFileLoadHook has been enabled 367 get_prohibited_capabilities()->can_retransform_classes = 1; 368 } 369 } 370 } 371 372 373 void 374 JvmtiEnvBase::record_class_file_load_hook_enabled() { 375 if (!_class_file_load_hook_ever_enabled) { 376 if (Threads::number_of_threads() == 0) { 377 record_first_time_class_file_load_hook_enabled(); 378 } else { 379 MutexLocker mu(JvmtiThreadState_lock); 380 record_first_time_class_file_load_hook_enabled(); 381 } 382 } 383 } 384 385 386 jvmtiError 387 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 388 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 389 "sanity check"); 390 391 int old_prefix_count = get_native_method_prefix_count(); 392 char **old_prefixes = get_native_method_prefixes(); 393 394 // allocate and install the new prefixex 395 if (prefix_count == 0 || !is_valid()) { 396 _native_method_prefix_count = 0; 397 _native_method_prefixes = NULL; 398 } else { 399 // there are prefixes, allocate an array to hold them, and fill it 400 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal); 401 if (new_prefixes == NULL) { 402 return JVMTI_ERROR_OUT_OF_MEMORY; 403 } 404 for (int i = 0; i < prefix_count; i++) { 405 char* prefix = prefixes[i]; 406 if (prefix == NULL) { 407 for (int j = 0; j < (i-1); j++) { 408 os::free(new_prefixes[j]); 409 } 410 os::free(new_prefixes); 411 return JVMTI_ERROR_NULL_POINTER; 412 } 413 prefix = os::strdup(prefixes[i]); 414 if (prefix == NULL) { 415 for (int j = 0; j < (i-1); j++) { 416 os::free(new_prefixes[j]); 417 } 418 os::free(new_prefixes); 419 return JVMTI_ERROR_OUT_OF_MEMORY; 420 } 421 new_prefixes[i] = prefix; 422 } 423 _native_method_prefix_count = prefix_count; 424 _native_method_prefixes = new_prefixes; 425 } 426 427 // now that we know the new prefixes have been successfully installed we can 428 // safely remove the old ones 429 if (old_prefix_count != 0) { 430 for (int i = 0; i < old_prefix_count; i++) { 431 os::free(old_prefixes[i]); 432 } 433 os::free(old_prefixes); 434 } 435 436 return JVMTI_ERROR_NONE; 437 } 438 439 440 // Collect all the prefixes which have been set in any JVM TI environments 441 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 442 // order of environments and the order of prefixes within each environment. 443 // Return in a resource allocated array. 444 char** 445 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 446 assert(Threads::number_of_threads() == 0 || 447 SafepointSynchronize::is_at_safepoint() || 448 JvmtiThreadState_lock->is_locked(), 449 "sanity check"); 450 451 int total_count = 0; 452 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 453 454 JvmtiEnvIterator it; 455 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 456 int prefix_count = env->get_native_method_prefix_count(); 457 char** prefixes = env->get_native_method_prefixes(); 458 for (int j = 0; j < prefix_count; j++) { 459 // retrieve a prefix and so that it is safe against asynchronous changes 460 // copy it into the resource area 461 char* prefix = prefixes[j]; 462 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 463 strcpy(prefix_copy, prefix); 464 prefix_array->at_put_grow(total_count++, prefix_copy); 465 } 466 } 467 468 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 469 char** p = all_prefixes; 470 for (int i = 0; i < total_count; ++i) { 471 *p++ = prefix_array->at(i); 472 } 473 *count_ptr = total_count; 474 return all_prefixes; 475 } 476 477 void 478 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 479 jint size_of_callbacks) { 480 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 481 482 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 483 484 // clear in either case to be sure we got any gap between sizes 485 memset(&_event_callbacks, 0, byte_cnt); 486 487 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 488 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 489 // occurs after the boiler-plate environment check and before the lock is acquired. 490 if (callbacks != NULL && is_valid()) { 491 if (size_of_callbacks < (jint)byte_cnt) { 492 byte_cnt = size_of_callbacks; 493 } 494 memcpy(&_event_callbacks, callbacks, byte_cnt); 495 } 496 } 497 498 499 // In the fullness of time, all users of the method should instead 500 // directly use allocate, besides being cleaner and faster, this will 501 // mean much better out of memory handling 502 unsigned char * 503 JvmtiEnvBase::jvmtiMalloc(jlong size) { 504 unsigned char* mem = NULL; 505 jvmtiError result = allocate(size, &mem); 506 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 507 return mem; 508 } 509 510 511 // Handle management 512 513 jobject JvmtiEnvBase::jni_reference(Handle hndl) { 514 return JNIHandles::make_local(hndl()); 515 } 516 517 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) { 518 return JNIHandles::make_local(thread, hndl()); 519 } 520 521 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) { 522 JNIHandles::destroy_local(jobj); 523 } 524 525 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) { 526 JNIHandles::destroy_local(jobj); // thread is unused. 527 } 528 529 // 530 // Threads 531 // 532 533 jobject * 534 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) { 535 if (length == 0) { 536 return NULL; 537 } 538 539 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length); 540 NULL_CHECK(objArray, NULL); 541 542 for (int i=0; i<length; i++) { 543 objArray[i] = jni_reference(handles[i]); 544 } 545 return objArray; 546 } 547 548 jthread * 549 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 550 return (jthread *) new_jobjectArray(length,handles); 551 } 552 553 jthreadGroup * 554 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) { 555 return (jthreadGroup *) new_jobjectArray(length,handles); 556 } 557 558 // return the vframe on the specified thread and depth, NULL if no such frame 559 vframe* 560 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) { 561 if (!java_thread->has_last_Java_frame()) { 562 return NULL; 563 } 564 RegisterMap reg_map(java_thread); 565 vframe *vf = java_thread->last_java_vframe(®_map); 566 int d = 0; 567 while ((vf != NULL) && (d < depth)) { 568 vf = vf->java_sender(); 569 d++; 570 } 571 return vf; 572 } 573 574 575 // 576 // utilities: JNI objects 577 // 578 579 580 jclass 581 JvmtiEnvBase::get_jni_class_non_null(Klass* k) { 582 assert(k != NULL, "k != NULL"); 583 Thread *thread = Thread::current(); 584 return (jclass)jni_reference(Handle(thread, k->java_mirror())); 585 } 586 587 // 588 // Field Information 589 // 590 591 bool 592 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) { 593 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 594 return false; 595 } 596 bool found = false; 597 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 598 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 599 found = id->find_local_field(fd); 600 } else { 601 // Non-static field. The fieldID is really the offset of the field within the object. 602 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 603 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 604 } 605 return found; 606 } 607 608 // 609 // Object Monitor Information 610 // 611 612 // 613 // Count the number of objects for a lightweight monitor. The hobj 614 // parameter is object that owns the monitor so this routine will 615 // count the number of times the same object was locked by frames 616 // in java_thread. 617 // 618 jint 619 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 620 jint ret = 0; 621 if (!java_thread->has_last_Java_frame()) { 622 return ret; // no Java frames so no monitors 623 } 624 625 ResourceMark rm; 626 HandleMark hm; 627 RegisterMap reg_map(java_thread); 628 629 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL; 630 jvf = jvf->java_sender()) { 631 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 632 if (!mons->is_empty()) { 633 for (int i = 0; i < mons->length(); i++) { 634 MonitorInfo *mi = mons->at(i); 635 if (mi->owner_is_scalar_replaced()) continue; 636 637 // see if owner of the monitor is our object 638 if (mi->owner() != NULL && mi->owner() == hobj()) { 639 ret++; 640 } 641 } 642 } 643 } 644 return ret; 645 } 646 647 648 649 jvmtiError 650 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) { 651 JavaThread *current_jt = JavaThread::current(); 652 assert(current_jt == java_thread || 653 current_jt == java_thread->active_handshaker(), 654 "call by myself or at direct handshake"); 655 oop obj = NULL; 656 // The ObjectMonitor* can't be async deflated since we are either 657 // at a safepoint or the calling thread is operating on itself so 658 // it cannot leave the underlying wait()/enter() call. 659 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 660 if (mon == NULL) { 661 // thread is not doing an Object.wait() call 662 mon = java_thread->current_pending_monitor(); 663 if (mon != NULL) { 664 // The thread is trying to enter() an ObjectMonitor. 665 obj = (oop)mon->object(); 666 assert(obj != NULL, "ObjectMonitor should have a valid object!"); 667 } 668 // implied else: no contended ObjectMonitor 669 } else { 670 // thread is doing an Object.wait() call 671 obj = (oop)mon->object(); 672 assert(obj != NULL, "Object.wait() should have an object"); 673 } 674 675 if (obj == NULL) { 676 *monitor_ptr = NULL; 677 } else { 678 HandleMark hm; 679 Handle hobj(current_jt, obj); 680 *monitor_ptr = jni_reference(calling_thread, hobj); 681 } 682 return JVMTI_ERROR_NONE; 683 } 684 685 686 jvmtiError 687 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 688 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 689 jvmtiError err = JVMTI_ERROR_NONE; 690 JavaThread *current_jt = JavaThread::current(); 691 assert(current_jt == java_thread || 692 current_jt == java_thread->active_handshaker(), 693 "call by myself or at direct handshake"); 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 // The ObjectMonitor* can't be async deflated since we are either 737 // at a safepoint or the calling thread is operating on itself so 738 // it cannot leave the underlying wait() call. 739 // Save object of current wait() call (if any) for later comparison. 740 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 741 if (mon != NULL) { 742 wait_obj = (oop)mon->object(); 743 } 744 } 745 oop pending_obj = NULL; 746 { 747 // The ObjectMonitor* can't be async deflated since we are either 748 // at a safepoint or the calling thread is operating on itself so 749 // it cannot leave the underlying enter() call. 750 // Save object of current enter() call (if any) for later comparison. 751 ObjectMonitor *mon = java_thread->current_pending_monitor(); 752 if (mon != NULL) { 753 pending_obj = (oop)mon->object(); 754 } 755 } 756 757 for (int i = 0; i < mons->length(); i++) { 758 MonitorInfo *mi = mons->at(i); 759 760 if (mi->owner_is_scalar_replaced()) continue; 761 762 oop obj = mi->owner(); 763 if (obj == NULL) { 764 // this monitor doesn't have an owning object so skip it 765 continue; 766 } 767 768 if (wait_obj == obj) { 769 // the thread is waiting on this monitor so it isn't really owned 770 continue; 771 } 772 773 if (pending_obj == obj) { 774 // the thread is pending on this monitor so it isn't really owned 775 continue; 776 } 777 778 if (owned_monitors_list->length() > 0) { 779 // Our list has at least one object on it so we have to check 780 // for recursive object locking 781 bool found = false; 782 for (int j = 0; j < owned_monitors_list->length(); j++) { 783 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 784 oop check = JNIHandles::resolve(jobj); 785 if (check == obj) { 786 found = true; // we found the object 787 break; 788 } 789 } 790 791 if (found) { 792 // already have this object so don't include it 793 continue; 794 } 795 } 796 797 // add the owning object to our list 798 jvmtiMonitorStackDepthInfo *jmsdi; 799 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 800 if (err != JVMTI_ERROR_NONE) { 801 return err; 802 } 803 Handle hobj(Thread::current(), obj); 804 jmsdi->monitor = jni_reference(calling_thread, hobj); 805 jmsdi->stack_depth = stack_depth; 806 owned_monitors_list->append(jmsdi); 807 } 808 809 return err; 810 } 811 812 jvmtiError 813 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 814 jint start_depth, jint max_count, 815 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 816 #ifdef ASSERT 817 uint32_t debug_bits = 0; 818 #endif 819 Thread *current_thread = Thread::current(); 820 assert(current_thread == java_thread || 821 SafepointSynchronize::is_at_safepoint() || 822 current_thread == java_thread->active_handshaker(), 823 "call by myself / at safepoint / at handshake"); 824 int count = 0; 825 if (java_thread->has_last_Java_frame()) { 826 RegisterMap reg_map(java_thread); 827 ResourceMark rm(current_thread); 828 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 829 HandleMark hm(current_thread); 830 if (start_depth != 0) { 831 if (start_depth > 0) { 832 for (int j = 0; j < start_depth && jvf != NULL; j++) { 833 jvf = jvf->java_sender(); 834 } 835 if (jvf == NULL) { 836 // start_depth is deeper than the stack depth 837 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 838 } 839 } else { // start_depth < 0 840 // we are referencing the starting depth based on the oldest 841 // part of the stack. 842 // optimize to limit the number of times that java_sender() is called 843 javaVFrame *jvf_cursor = jvf; 844 javaVFrame *jvf_prev = NULL; 845 javaVFrame *jvf_prev_prev = NULL; 846 int j = 0; 847 while (jvf_cursor != NULL) { 848 jvf_prev_prev = jvf_prev; 849 jvf_prev = jvf_cursor; 850 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) { 851 jvf_cursor = jvf_cursor->java_sender(); 852 } 853 } 854 if (j == start_depth) { 855 // previous pointer is exactly where we want to start 856 jvf = jvf_prev; 857 } else { 858 // we need to back up further to get to the right place 859 if (jvf_prev_prev == NULL) { 860 // the -start_depth is greater than the stack depth 861 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 862 } 863 // j now is the number of frames on the stack starting with 864 // jvf_prev, we start from jvf_prev_prev and move older on 865 // the stack that many, the result is -start_depth frames 866 // remaining. 867 jvf = jvf_prev_prev; 868 for (; j < 0; j++) { 869 jvf = jvf->java_sender(); 870 } 871 } 872 } 873 } 874 for (; count < max_count && jvf != NULL; count++) { 875 frame_buffer[count].method = jvf->method()->jmethod_id(); 876 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 877 jvf = jvf->java_sender(); 878 } 879 } else { 880 if (start_depth != 0) { 881 // no frames and there is a starting depth 882 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 883 } 884 } 885 *count_ptr = count; 886 return JVMTI_ERROR_NONE; 887 } 888 889 jvmtiError 890 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) { 891 assert((state != NULL), 892 "JavaThread should create JvmtiThreadState before calling this method"); 893 *count_ptr = state->count_frames(); 894 return JVMTI_ERROR_NONE; 895 } 896 897 jvmtiError 898 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 899 jmethodID* method_ptr, jlocation* location_ptr) { 900 #ifdef ASSERT 901 uint32_t debug_bits = 0; 902 #endif 903 assert((SafepointSynchronize::is_at_safepoint() || 904 java_thread->is_thread_fully_suspended(false, &debug_bits)), 905 "at safepoint or target thread is suspended"); 906 Thread* current_thread = Thread::current(); 907 ResourceMark rm(current_thread); 908 909 vframe *vf = vframeFor(java_thread, depth); 910 if (vf == NULL) { 911 return JVMTI_ERROR_NO_MORE_FRAMES; 912 } 913 914 // vframeFor should return a java frame. If it doesn't 915 // it means we've got an internal error and we return the 916 // error in product mode. In debug mode we will instead 917 // attempt to cast the vframe to a javaVFrame and will 918 // cause an assertion/crash to allow further diagnosis. 919 #ifdef PRODUCT 920 if (!vf->is_java_frame()) { 921 return JVMTI_ERROR_INTERNAL; 922 } 923 #endif 924 925 HandleMark hm(current_thread); 926 javaVFrame *jvf = javaVFrame::cast(vf); 927 Method* method = jvf->method(); 928 if (method->is_native()) { 929 *location_ptr = -1; 930 } else { 931 *location_ptr = jvf->bci(); 932 } 933 *method_ptr = method->jmethod_id(); 934 935 return JVMTI_ERROR_NONE; 936 } 937 938 939 jvmtiError 940 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 941 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 942 Thread* current_thread = VMThread::vm_thread(); 943 assert(current_thread == Thread::current(), "must be"); 944 945 HandleMark hm(current_thread); 946 Handle hobj; 947 948 // Check arguments 949 { 950 oop mirror = JNIHandles::resolve_external_guard(object); 951 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 952 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 953 954 hobj = Handle(current_thread, mirror); 955 } 956 957 ThreadsListHandle tlh(current_thread); 958 JavaThread *owning_thread = NULL; 959 ObjectMonitor *mon = NULL; 960 jvmtiMonitorUsage ret = { 961 NULL, 0, 0, NULL, 0, NULL 962 }; 963 964 uint32_t debug_bits = 0; 965 // first derive the object's owner and entry_count (if any) 966 { 967 // Revoke any biases before querying the mark word 968 BiasedLocking::revoke_at_safepoint(hobj); 969 970 address owner = NULL; 971 { 972 markWord mark = hobj()->mark(); 973 974 if (!mark.has_monitor()) { 975 // this object has a lightweight monitor 976 977 if (mark.has_locker()) { 978 owner = (address)mark.locker(); // save the address of the Lock word 979 } 980 // implied else: no owner 981 } else { 982 // this object has a heavyweight monitor 983 mon = mark.monitor(); 984 985 // The owner field of a heavyweight monitor may be NULL for no 986 // owner, a JavaThread * or it may still be the address of the 987 // Lock word in a JavaThread's stack. A monitor can be inflated 988 // by a non-owning JavaThread, but only the owning JavaThread 989 // can change the owner field from the Lock word to the 990 // JavaThread * and it may not have done that yet. 991 owner = (address)mon->owner(); 992 } 993 } 994 995 if (owner != NULL) { 996 // This monitor is owned so we have to find the owning JavaThread. 997 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner); 998 assert(owning_thread != NULL, "owning JavaThread must not be NULL"); 999 Handle th(current_thread, owning_thread->threadObj()); 1000 ret.owner = (jthread)jni_reference(calling_thread, th); 1001 } 1002 1003 if (owning_thread != NULL) { // monitor is owned 1004 // The recursions field of a monitor does not reflect recursions 1005 // as lightweight locks before inflating the monitor are not included. 1006 // We have to count the number of recursive monitor entries the hard way. 1007 // We pass a handle to survive any GCs along the way. 1008 ResourceMark rm(current_thread); 1009 ret.entry_count = count_locked_objects(owning_thread, hobj); 1010 } 1011 // implied else: entry_count == 0 1012 } 1013 1014 jint nWant = 0, nWait = 0; 1015 if (mon != NULL) { 1016 // this object has a heavyweight monitor 1017 nWant = mon->contentions(); // # of threads contending for monitor 1018 nWait = mon->waiters(); // # of threads in Object.wait() 1019 ret.waiter_count = nWant + nWait; 1020 ret.notify_waiter_count = nWait; 1021 } else { 1022 // this object has a lightweight monitor 1023 ret.waiter_count = 0; 1024 ret.notify_waiter_count = 0; 1025 } 1026 1027 // Allocate memory for heavyweight and lightweight monitor. 1028 jvmtiError err; 1029 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1030 if (err != JVMTI_ERROR_NONE) { 1031 return err; 1032 } 1033 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1034 (unsigned char**)&ret.notify_waiters); 1035 if (err != JVMTI_ERROR_NONE) { 1036 deallocate((unsigned char*)ret.waiters); 1037 return err; 1038 } 1039 1040 // now derive the rest of the fields 1041 if (mon != NULL) { 1042 // this object has a heavyweight monitor 1043 1044 // Number of waiters may actually be less than the waiter count. 1045 // So NULL out memory so that unused memory will be NULL. 1046 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1047 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1048 1049 if (ret.waiter_count > 0) { 1050 // we have contending and/or waiting threads 1051 if (nWant > 0) { 1052 // we have contending threads 1053 ResourceMark rm(current_thread); 1054 // get_pending_threads returns only java thread so we do not need to 1055 // check for non java threads. 1056 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon); 1057 if (wantList->length() < nWant) { 1058 // robustness: the pending list has gotten smaller 1059 nWant = wantList->length(); 1060 } 1061 for (int i = 0; i < nWant; i++) { 1062 JavaThread *pending_thread = wantList->at(i); 1063 Handle th(current_thread, pending_thread->threadObj()); 1064 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1065 } 1066 } 1067 if (nWait > 0) { 1068 // we have threads in Object.wait() 1069 int offset = nWant; // add after any contending threads 1070 ObjectWaiter *waiter = mon->first_waiter(); 1071 for (int i = 0, j = 0; i < nWait; i++) { 1072 if (waiter == NULL) { 1073 // robustness: the waiting list has gotten smaller 1074 nWait = j; 1075 break; 1076 } 1077 Thread *t = mon->thread_of_waiter(waiter); 1078 if (t != NULL && t->is_Java_thread()) { 1079 JavaThread *wjava_thread = (JavaThread *)t; 1080 // If the thread was found on the ObjectWaiter list, then 1081 // it has not been notified. This thread can't change the 1082 // state of the monitor so it doesn't need to be suspended. 1083 Handle th(current_thread, wjava_thread->threadObj()); 1084 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th); 1085 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th); 1086 } 1087 waiter = mon->next_waiter(waiter); 1088 } 1089 } 1090 } // ThreadsListHandle is destroyed here. 1091 1092 // Adjust count. nWant and nWait count values may be less than original. 1093 ret.waiter_count = nWant + nWait; 1094 ret.notify_waiter_count = nWait; 1095 } else { 1096 // this object has a lightweight monitor and we have nothing more 1097 // to do here because the defaults are just fine. 1098 } 1099 1100 // we don't update return parameter unless everything worked 1101 *info_ptr = ret; 1102 1103 return JVMTI_ERROR_NONE; 1104 } 1105 1106 ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1107 _env = env; 1108 _allocations = new (ResourceObj::C_HEAP, mtServiceability) GrowableArray<unsigned char*>(20, mtServiceability); 1109 _failed = false; 1110 } 1111 ResourceTracker::~ResourceTracker() { 1112 if (_failed) { 1113 for (int i=0; i<_allocations->length(); i++) { 1114 _env->deallocate(_allocations->at(i)); 1115 } 1116 } 1117 delete _allocations; 1118 } 1119 1120 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1121 unsigned char *ptr; 1122 jvmtiError err = _env->allocate(size, &ptr); 1123 if (err == JVMTI_ERROR_NONE) { 1124 _allocations->append(ptr); 1125 *mem_ptr = ptr; 1126 } else { 1127 *mem_ptr = NULL; 1128 _failed = true; 1129 } 1130 return err; 1131 } 1132 1133 unsigned char* ResourceTracker::allocate(jlong size) { 1134 unsigned char* ptr; 1135 allocate(size, &ptr); 1136 return ptr; 1137 } 1138 1139 char* ResourceTracker::strdup(const char* str) { 1140 char *dup_str = (char*)allocate(strlen(str)+1); 1141 if (dup_str != NULL) { 1142 strcpy(dup_str, str); 1143 } 1144 return dup_str; 1145 } 1146 1147 struct StackInfoNode { 1148 struct StackInfoNode *next; 1149 jvmtiStackInfo info; 1150 }; 1151 1152 // Create a jvmtiStackInfo inside a linked list node and create a 1153 // buffer for the frame information, both allocated as resource objects. 1154 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1155 // Note that either or both of thr and thread_oop 1156 // may be null if the thread is new or has exited. 1157 void 1158 MultipleStackTracesCollector::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1159 assert(SafepointSynchronize::is_at_safepoint() || 1160 Thread::current() == thr->active_handshaker(), 1161 "must be at safepoint or at direct handshake"); 1162 1163 jint state = 0; 1164 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1165 jvmtiStackInfo *infop = &(node->info); 1166 node->next = head(); 1167 set_head(node); 1168 infop->frame_count = 0; 1169 infop->thread = jt; 1170 1171 if (thread_oop != NULL) { 1172 // get most state bits 1173 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 1174 } 1175 1176 if (thr != NULL) { // add more state bits if there is a JavaThead to query 1177 // same as is_being_ext_suspended() but without locking 1178 if (thr->is_ext_suspended() || thr->is_external_suspend()) { 1179 state |= JVMTI_THREAD_STATE_SUSPENDED; 1180 } 1181 JavaThreadState jts = thr->thread_state(); 1182 if (jts == _thread_in_native) { 1183 state |= JVMTI_THREAD_STATE_IN_NATIVE; 1184 } 1185 if (thr->is_interrupted(false)) { 1186 state |= JVMTI_THREAD_STATE_INTERRUPTED; 1187 } 1188 } 1189 infop->state = state; 1190 1191 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1192 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1193 env()->get_stack_trace(thr, 0, max_frame_count(), 1194 infop->frame_buffer, &(infop->frame_count)); 1195 } else { 1196 infop->frame_buffer = NULL; 1197 infop->frame_count = 0; 1198 } 1199 _frame_count_total += infop->frame_count; 1200 } 1201 1202 // Based on the stack information in the linked list, allocate memory 1203 // block to return and fill it from the info in the linked list. 1204 void 1205 MultipleStackTracesCollector::allocate_and_fill_stacks(jint thread_count) { 1206 // do I need to worry about alignment issues? 1207 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1208 + _frame_count_total * sizeof(jvmtiFrameInfo); 1209 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1210 1211 // pointers to move through the newly allocated space as it is filled in 1212 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1213 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1214 1215 // copy information in resource area into allocated buffer 1216 // insert stack info backwards since linked list is backwards 1217 // insert frame info forwards 1218 // walk the StackInfoNodes 1219 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) { 1220 jint frame_count = sin->info.frame_count; 1221 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1222 --si; 1223 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1224 if (frames_size == 0) { 1225 si->frame_buffer = NULL; 1226 } else { 1227 memcpy(fi, sin->info.frame_buffer, frames_size); 1228 si->frame_buffer = fi; // point to the new allocated copy of the frames 1229 fi += frame_count; 1230 } 1231 } 1232 assert(si == _stack_info, "the last copied stack info must be the first record"); 1233 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1234 "the last copied frame info must be the last record"); 1235 } 1236 1237 1238 void 1239 VM_GetThreadListStackTraces::doit() { 1240 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1241 1242 ResourceMark rm; 1243 ThreadsListHandle tlh; 1244 for (int i = 0; i < _thread_count; ++i) { 1245 jthread jt = _thread_list[i]; 1246 JavaThread* java_thread = NULL; 1247 oop thread_oop = NULL; 1248 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop); 1249 if (err != JVMTI_ERROR_NONE) { 1250 // We got an error code so we don't have a JavaThread *, but 1251 // only return an error from here if we didn't get a valid 1252 // thread_oop. 1253 if (thread_oop == NULL) { 1254 _collector.set_result(err); 1255 return; 1256 } 1257 // We have a valid thread_oop. 1258 } 1259 _collector.fill_frames(jt, java_thread, thread_oop); 1260 } 1261 _collector.allocate_and_fill_stacks(_thread_count); 1262 } 1263 1264 void 1265 GetSingleStackTraceClosure::do_thread(Thread *target) { 1266 assert(target->is_Java_thread(), "just checking"); 1267 JavaThread *jt = (JavaThread *)target; 1268 oop thread_oop = jt->threadObj(); 1269 1270 if (!jt->is_exiting() && (thread_oop != NULL)) { 1271 ResourceMark rm; 1272 _collector.fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1273 jt, thread_oop); 1274 _collector.allocate_and_fill_stacks(1); 1275 _collector.set_result(JVMTI_ERROR_NONE); 1276 } 1277 } 1278 1279 void 1280 VM_GetAllStackTraces::doit() { 1281 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1282 1283 ResourceMark rm; 1284 _final_thread_count = 0; 1285 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1286 oop thread_oop = jt->threadObj(); 1287 if (thread_oop != NULL && 1288 !jt->is_exiting() && 1289 java_lang_Thread::is_alive(thread_oop) && 1290 !jt->is_hidden_from_external_view()) { 1291 ++_final_thread_count; 1292 // Handle block of the calling thread is used to create local refs. 1293 _collector.fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1294 jt, thread_oop); 1295 } 1296 } 1297 _collector.allocate_and_fill_stacks(_final_thread_count); 1298 } 1299 1300 // Verifies that the top frame is a java frame in an expected state. 1301 // Deoptimizes frame if needed. 1302 // Checks that the frame method signature matches the return type (tos). 1303 // HandleMark must be defined in the caller only. 1304 // It is to keep a ret_ob_h handle alive after return to the caller. 1305 jvmtiError 1306 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread, 1307 jvalue value, TosState tos, Handle* ret_ob_h) { 1308 ResourceMark rm(current_thread); 1309 1310 vframe *vf = vframeFor(java_thread, 0); 1311 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES); 1312 1313 javaVFrame *jvf = (javaVFrame*) vf; 1314 if (!vf->is_java_frame() || jvf->method()->is_native()) { 1315 return JVMTI_ERROR_OPAQUE_FRAME; 1316 } 1317 1318 // If the frame is a compiled one, need to deoptimize it. 1319 if (vf->is_compiled_frame()) { 1320 if (!vf->fr().can_be_deoptimized()) { 1321 return JVMTI_ERROR_OPAQUE_FRAME; 1322 } 1323 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 1324 } 1325 1326 // Get information about method return type 1327 Symbol* signature = jvf->method()->signature(); 1328 1329 ResultTypeFinder rtf(signature); 1330 TosState fr_tos = as_TosState(rtf.type()); 1331 if (fr_tos != tos) { 1332 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) { 1333 return JVMTI_ERROR_TYPE_MISMATCH; 1334 } 1335 } 1336 1337 // Check that the jobject class matches the return type signature. 1338 jobject jobj = value.l; 1339 if (tos == atos && jobj != NULL) { // NULL reference is allowed 1340 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj)); 1341 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 1342 Klass* ob_k = ob_h()->klass(); 1343 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT); 1344 1345 // Method return type signature. 1346 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC); 1347 1348 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) { 1349 return JVMTI_ERROR_TYPE_MISMATCH; 1350 } 1351 *ret_ob_h = ob_h; 1352 } 1353 return JVMTI_ERROR_NONE; 1354 } /* end check_top_frame */ 1355 1356 1357 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 1358 // Main difference is on the last stage in the interpreter. 1359 // The PopFrame stops method execution to continue execution 1360 // from the same method call instruction. 1361 // The ForceEarlyReturn forces return from method so the execution 1362 // continues at the bytecode following the method call. 1363 1364 // Threads_lock NOT held, java_thread not protected by lock 1365 // java_thread - pre-checked 1366 1367 jvmtiError 1368 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) { 1369 JavaThread* current_thread = JavaThread::current(); 1370 HandleMark hm(current_thread); 1371 uint32_t debug_bits = 0; 1372 1373 // retrieve or create the state 1374 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 1375 if (state == NULL) { 1376 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1377 } 1378 1379 // Check if java_thread is fully suspended 1380 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) { 1381 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1382 } 1383 1384 // Check to see if a ForceEarlyReturn was already in progress 1385 if (state->is_earlyret_pending()) { 1386 // Probably possible for JVMTI clients to trigger this, but the 1387 // JPDA backend shouldn't allow this to happen 1388 return JVMTI_ERROR_INTERNAL; 1389 } 1390 { 1391 // The same as for PopFrame. Workaround bug: 1392 // 4812902: popFrame hangs if the method is waiting at a synchronize 1393 // Catch this condition and return an error to avoid hanging. 1394 // Now JVMTI spec allows an implementation to bail out with an opaque 1395 // frame error. 1396 OSThread* osThread = java_thread->osthread(); 1397 if (osThread->get_state() == MONITOR_WAIT) { 1398 return JVMTI_ERROR_OPAQUE_FRAME; 1399 } 1400 } 1401 Handle ret_ob_h; 1402 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h); 1403 if (err != JVMTI_ERROR_NONE) { 1404 return err; 1405 } 1406 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL, 1407 "return object oop must not be NULL if jobject is not NULL"); 1408 1409 // Update the thread state to reflect that the top frame must be 1410 // forced to return. 1411 // The current frame will be returned later when the suspended 1412 // thread is resumed and right before returning from VM to Java. 1413 // (see call_VM_base() in assembler_<cpu>.cpp). 1414 1415 state->set_earlyret_pending(); 1416 state->set_earlyret_oop(ret_ob_h()); 1417 state->set_earlyret_value(value, tos); 1418 1419 // Set pending step flag for this early return. 1420 // It is cleared when next step event is posted. 1421 state->set_pending_step_for_earlyret(); 1422 1423 return JVMTI_ERROR_NONE; 1424 } /* end force_early_return */ 1425 1426 void 1427 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 1428 if ( _error != JVMTI_ERROR_NONE) { 1429 // Error occurred in previous iteration so no need to add 1430 // to the list. 1431 return; 1432 } 1433 if (mon->owner() == _java_thread ) { 1434 // Filter out on stack monitors collected during stack walk. 1435 oop obj = (oop)mon->object(); 1436 bool found = false; 1437 for (int j = 0; j < _owned_monitors_list->length(); j++) { 1438 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 1439 oop check = JNIHandles::resolve(jobj); 1440 if (check == obj) { 1441 // On stack monitor already collected during the stack walk. 1442 found = true; 1443 break; 1444 } 1445 } 1446 if (found == false) { 1447 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 1448 jvmtiError err; 1449 jvmtiMonitorStackDepthInfo *jmsdi; 1450 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1451 if (err != JVMTI_ERROR_NONE) { 1452 _error = err; 1453 return; 1454 } 1455 Handle hobj(Thread::current(), obj); 1456 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 1457 // stack depth is unknown for this monitor. 1458 jmsdi->stack_depth = -1; 1459 _owned_monitors_list->append(jmsdi); 1460 } 1461 } 1462 } 1463 1464 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL; 1465 1466 void JvmtiModuleClosure::do_module(ModuleEntry* entry) { 1467 assert_locked_or_safepoint(Module_lock); 1468 OopHandle module = entry->module_handle(); 1469 guarantee(module.resolve() != NULL, "module object is NULL"); 1470 _tbl->push(module); 1471 } 1472 1473 jvmtiError 1474 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) { 1475 ResourceMark rm; 1476 MutexLocker mcld(ClassLoaderDataGraph_lock); 1477 MutexLocker ml(Module_lock); 1478 1479 _tbl = new GrowableArray<OopHandle>(77); 1480 if (_tbl == NULL) { 1481 return JVMTI_ERROR_OUT_OF_MEMORY; 1482 } 1483 1484 // Iterate over all the modules loaded to the system. 1485 ClassLoaderDataGraph::modules_do(&do_module); 1486 1487 jint len = _tbl->length(); 1488 guarantee(len > 0, "at least one module must be present"); 1489 1490 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject))); 1491 if (array == NULL) { 1492 return JVMTI_ERROR_OUT_OF_MEMORY; 1493 } 1494 for (jint idx = 0; idx < len; idx++) { 1495 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve()); 1496 } 1497 _tbl = NULL; 1498 *modules_ptr = array; 1499 *module_count_ptr = len; 1500 return JVMTI_ERROR_NONE; 1501 } 1502 1503 void 1504 VM_UpdateForPopTopFrame::doit() { 1505 JavaThread* jt = _state->get_thread(); 1506 ThreadsListHandle tlh; 1507 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1508 _state->update_for_pop_top_frame(); 1509 } else { 1510 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1511 } 1512 } 1513 1514 void 1515 VM_SetFramePop::doit() { 1516 JavaThread* jt = _state->get_thread(); 1517 ThreadsListHandle tlh; 1518 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1519 int frame_number = _state->count_frames() - _depth; 1520 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number); 1521 } else { 1522 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1523 } 1524 } 1525 1526 void 1527 GetOwnedMonitorInfoClosure::do_thread(Thread *target) { 1528 assert(target->is_Java_thread(), "just checking"); 1529 JavaThread *jt = (JavaThread *)target; 1530 if (!jt->is_exiting() && (jt->threadObj() != NULL)) { 1531 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, 1532 jt, 1533 _owned_monitors_list); 1534 } 1535 } 1536 1537 void 1538 GetCurrentContendedMonitorClosure::do_thread(Thread *target) { 1539 assert(target->is_Java_thread(), "just checking"); 1540 JavaThread *jt = (JavaThread *)target; 1541 if (!jt->is_exiting() && (jt->threadObj() != NULL)) { 1542 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread, 1543 jt, 1544 _owned_monitor_ptr); 1545 } 1546 } 1547 1548 void 1549 GetStackTraceClosure::do_thread(Thread *target) { 1550 assert(target->is_Java_thread(), "just checking"); 1551 JavaThread *jt = (JavaThread *)target; 1552 if (!jt->is_exiting() && (jt->threadObj() != NULL)) { 1553 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(jt, 1554 _start_depth, _max_count, 1555 _frame_buffer, _count_ptr); 1556 } 1557 } 1558 1559 void 1560 VM_GetFrameCount::doit() { 1561 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1562 JavaThread* jt = _state->get_thread(); 1563 ThreadsListHandle tlh; 1564 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1565 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr); 1566 } 1567 } 1568 1569 void 1570 VM_GetFrameLocation::doit() { 1571 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1572 ThreadsListHandle tlh; 1573 if (_java_thread != NULL && tlh.includes(_java_thread) 1574 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1575 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth, 1576 _method_ptr, _location_ptr); 1577 } 1578 }