1 /* 2 * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "jvmtifiles/jvmtiEnv.hpp" 28 #include "memory/resourceArea.hpp" 29 #include "oops/objArrayKlass.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/oop.inline.hpp" 32 #include "prims/jvmtiEnvBase.hpp" 33 #include "prims/jvmtiEventController.inline.hpp" 34 #include "prims/jvmtiExtensions.hpp" 35 #include "prims/jvmtiImpl.hpp" 36 #include "prims/jvmtiManageCapabilities.hpp" 37 #include "prims/jvmtiTagMap.hpp" 38 #include "prims/jvmtiThreadState.inline.hpp" 39 #include "runtime/biasedLocking.hpp" 40 #include "runtime/deoptimization.hpp" 41 #include "runtime/frame.inline.hpp" 42 #include "runtime/interfaceSupport.inline.hpp" 43 #include "runtime/jfieldIDWorkaround.hpp" 44 #include "runtime/jniHandles.inline.hpp" 45 #include "runtime/objectMonitor.hpp" 46 #include "runtime/objectMonitor.inline.hpp" 47 #include "runtime/signature.hpp" 48 #include "runtime/thread.inline.hpp" 49 #include "runtime/threadSMR.hpp" 50 #include "runtime/vframe.hpp" 51 #include "runtime/vframe_hp.hpp" 52 #include "runtime/vmThread.hpp" 53 #include "runtime/vm_operations.hpp" 54 55 /////////////////////////////////////////////////////////////// 56 // 57 // JvmtiEnvBase 58 // 59 60 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL; 61 62 bool JvmtiEnvBase::_globally_initialized = false; 63 volatile bool JvmtiEnvBase::_needs_clean_up = false; 64 65 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 66 67 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 68 69 extern jvmtiInterface_1_ jvmti_Interface; 70 extern jvmtiInterface_1_ jvmtiTrace_Interface; 71 72 73 // perform initializations that must occur before any JVMTI environments 74 // are released but which should only be initialized once (no matter 75 // how many environments are created). 76 void 77 JvmtiEnvBase::globally_initialize() { 78 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 79 assert(_globally_initialized == false, "bad call"); 80 81 JvmtiManageCapabilities::initialize(); 82 83 // register extension functions and events 84 JvmtiExtensions::register_extensions(); 85 86 #ifdef JVMTI_TRACE 87 JvmtiTrace::initialize(); 88 #endif 89 90 _globally_initialized = true; 91 } 92 93 94 void 95 JvmtiEnvBase::initialize() { 96 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 97 98 // Add this environment to the end of the environment list (order is important) 99 { 100 // This block of code must not contain any safepoints, as list deallocation 101 // (which occurs at a safepoint) cannot occur simultaneously with this list 102 // addition. Note: NoSafepointVerifier cannot, currently, be used before 103 // threads exist. 104 JvmtiEnvIterator it; 105 JvmtiEnvBase *previous_env = NULL; 106 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 107 previous_env = env; 108 } 109 if (previous_env == NULL) { 110 _head_environment = this; 111 } else { 112 previous_env->set_next_environment(this); 113 } 114 } 115 116 if (_globally_initialized == false) { 117 globally_initialize(); 118 } 119 } 120 121 jvmtiPhase 122 JvmtiEnvBase::phase() { 123 // For the JVMTI environments possessed the can_generate_early_vmstart: 124 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START 125 if (_phase == JVMTI_PHASE_PRIMORDIAL && 126 JvmtiExport::early_vmstart_recorded() && 127 early_vmstart_env()) { 128 return JVMTI_PHASE_START; 129 } 130 return _phase; // Normal case 131 } 132 133 bool 134 JvmtiEnvBase::is_valid() { 135 jint value = 0; 136 137 // This object might not be a JvmtiEnvBase so we can't assume 138 // the _magic field is properly aligned. Get the value in a safe 139 // way and then check against JVMTI_MAGIC. 140 141 switch (sizeof(_magic)) { 142 case 2: 143 value = Bytes::get_native_u2((address)&_magic); 144 break; 145 146 case 4: 147 value = Bytes::get_native_u4((address)&_magic); 148 break; 149 150 case 8: 151 value = Bytes::get_native_u8((address)&_magic); 152 break; 153 154 default: 155 guarantee(false, "_magic field is an unexpected size"); 156 } 157 158 return value == JVMTI_MAGIC; 159 } 160 161 162 bool 163 JvmtiEnvBase::use_version_1_0_semantics() { 164 int major, minor, micro; 165 166 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 167 return major == 1 && minor == 0; // micro version doesn't matter here 168 } 169 170 171 bool 172 JvmtiEnvBase::use_version_1_1_semantics() { 173 int major, minor, micro; 174 175 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 176 return major == 1 && minor == 1; // micro version doesn't matter here 177 } 178 179 bool 180 JvmtiEnvBase::use_version_1_2_semantics() { 181 int major, minor, micro; 182 183 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 184 return major == 1 && minor == 2; // micro version doesn't matter here 185 } 186 187 188 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 189 _version = version; 190 _env_local_storage = NULL; 191 _tag_map = NULL; 192 _native_method_prefix_count = 0; 193 _native_method_prefixes = NULL; 194 _next = NULL; 195 _class_file_load_hook_ever_enabled = false; 196 197 // Moot since ClassFileLoadHook not yet enabled. 198 // But "true" will give a more predictable ClassFileLoadHook behavior 199 // for environment creation during ClassFileLoadHook. 200 _is_retransformable = true; 201 202 // all callbacks initially NULL 203 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks)); 204 205 // all capabilities initially off 206 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 207 208 // all prohibited capabilities initially off 209 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 210 211 _magic = JVMTI_MAGIC; 212 213 JvmtiEventController::env_initialize((JvmtiEnv*)this); 214 215 #ifdef JVMTI_TRACE 216 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface; 217 #else 218 _jvmti_external.functions = &jvmti_Interface; 219 #endif 220 } 221 222 223 void 224 JvmtiEnvBase::dispose() { 225 226 #ifdef JVMTI_TRACE 227 JvmtiTrace::shutdown(); 228 #endif 229 230 // Dispose of event info and let the event controller call us back 231 // in a locked state (env_dispose, below) 232 JvmtiEventController::env_dispose(this); 233 } 234 235 void 236 JvmtiEnvBase::env_dispose() { 237 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 238 239 // We have been entered with all events disabled on this environment. 240 // A race to re-enable events (by setting callbacks) is prevented by 241 // checking for a valid environment when setting callbacks (while 242 // holding the JvmtiThreadState_lock). 243 244 // Mark as invalid. 245 _magic = DISPOSED_MAGIC; 246 247 // Relinquish all capabilities. 248 jvmtiCapabilities *caps = get_capabilities(); 249 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 250 251 // Same situation as with events (see above) 252 set_native_method_prefixes(0, NULL); 253 254 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 255 set_tag_map(NULL); 256 // A tag map can be big, deallocate it now 257 if (tag_map_to_deallocate != NULL) { 258 delete tag_map_to_deallocate; 259 } 260 261 _needs_clean_up = true; 262 } 263 264 265 JvmtiEnvBase::~JvmtiEnvBase() { 266 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 267 268 // There is a small window of time during which the tag map of a 269 // disposed environment could have been reallocated. 270 // Make sure it is gone. 271 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 272 set_tag_map(NULL); 273 // A tag map can be big, deallocate it now 274 if (tag_map_to_deallocate != NULL) { 275 delete tag_map_to_deallocate; 276 } 277 278 _magic = BAD_MAGIC; 279 } 280 281 282 void 283 JvmtiEnvBase::periodic_clean_up() { 284 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 285 286 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 287 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 288 JvmtiThreadState::periodic_clean_up(); 289 290 // Unlink all invalid environments from the list of environments 291 // and deallocate them 292 JvmtiEnvIterator it; 293 JvmtiEnvBase* previous_env = NULL; 294 JvmtiEnvBase* env = it.first(); 295 while (env != NULL) { 296 if (env->is_valid()) { 297 previous_env = env; 298 env = it.next(env); 299 } else { 300 // This one isn't valid, remove it from the list and deallocate it 301 JvmtiEnvBase* defunct_env = env; 302 env = it.next(env); 303 if (previous_env == NULL) { 304 _head_environment = env; 305 } else { 306 previous_env->set_next_environment(env); 307 } 308 delete defunct_env; 309 } 310 } 311 312 } 313 314 315 void 316 JvmtiEnvBase::check_for_periodic_clean_up() { 317 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 318 319 class ThreadInsideIterationClosure: public ThreadClosure { 320 private: 321 bool _inside; 322 public: 323 ThreadInsideIterationClosure() : _inside(false) {}; 324 325 void do_thread(Thread* thread) { 326 _inside |= thread->is_inside_jvmti_env_iteration(); 327 } 328 329 bool is_inside_jvmti_env_iteration() { 330 return _inside; 331 } 332 }; 333 334 if (_needs_clean_up) { 335 // Check if we are currently iterating environment, 336 // deallocation should not occur if we are 337 ThreadInsideIterationClosure tiic; 338 Threads::threads_do(&tiic); 339 if (!tiic.is_inside_jvmti_env_iteration() && 340 !is_inside_dying_thread_env_iteration()) { 341 _needs_clean_up = false; 342 JvmtiEnvBase::periodic_clean_up(); 343 } 344 } 345 } 346 347 348 void 349 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 350 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 351 "sanity check"); 352 353 if (!_class_file_load_hook_ever_enabled) { 354 _class_file_load_hook_ever_enabled = true; 355 356 if (get_capabilities()->can_retransform_classes) { 357 _is_retransformable = true; 358 } else { 359 _is_retransformable = false; 360 361 // cannot add retransform capability after ClassFileLoadHook has been enabled 362 get_prohibited_capabilities()->can_retransform_classes = 1; 363 } 364 } 365 } 366 367 368 void 369 JvmtiEnvBase::record_class_file_load_hook_enabled() { 370 if (!_class_file_load_hook_ever_enabled) { 371 if (Threads::number_of_threads() == 0) { 372 record_first_time_class_file_load_hook_enabled(); 373 } else { 374 MutexLocker mu(JvmtiThreadState_lock); 375 record_first_time_class_file_load_hook_enabled(); 376 } 377 } 378 } 379 380 381 jvmtiError 382 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 383 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 384 "sanity check"); 385 386 int old_prefix_count = get_native_method_prefix_count(); 387 char **old_prefixes = get_native_method_prefixes(); 388 389 // allocate and install the new prefixex 390 if (prefix_count == 0 || !is_valid()) { 391 _native_method_prefix_count = 0; 392 _native_method_prefixes = NULL; 393 } else { 394 // there are prefixes, allocate an array to hold them, and fill it 395 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal); 396 if (new_prefixes == NULL) { 397 return JVMTI_ERROR_OUT_OF_MEMORY; 398 } 399 for (int i = 0; i < prefix_count; i++) { 400 char* prefix = prefixes[i]; 401 if (prefix == NULL) { 402 for (int j = 0; j < (i-1); j++) { 403 os::free(new_prefixes[j]); 404 } 405 os::free(new_prefixes); 406 return JVMTI_ERROR_NULL_POINTER; 407 } 408 prefix = os::strdup(prefixes[i]); 409 if (prefix == NULL) { 410 for (int j = 0; j < (i-1); j++) { 411 os::free(new_prefixes[j]); 412 } 413 os::free(new_prefixes); 414 return JVMTI_ERROR_OUT_OF_MEMORY; 415 } 416 new_prefixes[i] = prefix; 417 } 418 _native_method_prefix_count = prefix_count; 419 _native_method_prefixes = new_prefixes; 420 } 421 422 // now that we know the new prefixes have been successfully installed we can 423 // safely remove the old ones 424 if (old_prefix_count != 0) { 425 for (int i = 0; i < old_prefix_count; i++) { 426 os::free(old_prefixes[i]); 427 } 428 os::free(old_prefixes); 429 } 430 431 return JVMTI_ERROR_NONE; 432 } 433 434 435 // Collect all the prefixes which have been set in any JVM TI environments 436 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 437 // order of environments and the order of prefixes within each environment. 438 // Return in a resource allocated array. 439 char** 440 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 441 assert(Threads::number_of_threads() == 0 || 442 SafepointSynchronize::is_at_safepoint() || 443 JvmtiThreadState_lock->is_locked(), 444 "sanity check"); 445 446 int total_count = 0; 447 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 448 449 JvmtiEnvIterator it; 450 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 451 int prefix_count = env->get_native_method_prefix_count(); 452 char** prefixes = env->get_native_method_prefixes(); 453 for (int j = 0; j < prefix_count; j++) { 454 // retrieve a prefix and so that it is safe against asynchronous changes 455 // copy it into the resource area 456 char* prefix = prefixes[j]; 457 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 458 strcpy(prefix_copy, prefix); 459 prefix_array->at_put_grow(total_count++, prefix_copy); 460 } 461 } 462 463 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 464 char** p = all_prefixes; 465 for (int i = 0; i < total_count; ++i) { 466 *p++ = prefix_array->at(i); 467 } 468 *count_ptr = total_count; 469 return all_prefixes; 470 } 471 472 void 473 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 474 jint size_of_callbacks) { 475 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 476 477 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 478 479 // clear in either case to be sure we got any gap between sizes 480 memset(&_event_callbacks, 0, byte_cnt); 481 482 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 483 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 484 // occurs after the boiler-plate environment check and before the lock is acquired. 485 if (callbacks != NULL && is_valid()) { 486 if (size_of_callbacks < (jint)byte_cnt) { 487 byte_cnt = size_of_callbacks; 488 } 489 memcpy(&_event_callbacks, callbacks, byte_cnt); 490 } 491 } 492 493 494 // In the fullness of time, all users of the method should instead 495 // directly use allocate, besides being cleaner and faster, this will 496 // mean much better out of memory handling 497 unsigned char * 498 JvmtiEnvBase::jvmtiMalloc(jlong size) { 499 unsigned char* mem = NULL; 500 jvmtiError result = allocate(size, &mem); 501 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 502 return mem; 503 } 504 505 506 // Handle management 507 508 jobject JvmtiEnvBase::jni_reference(Handle hndl) { 509 return JNIHandles::make_local(hndl()); 510 } 511 512 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) { 513 return JNIHandles::make_local(thread, hndl()); 514 } 515 516 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) { 517 JNIHandles::destroy_local(jobj); 518 } 519 520 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) { 521 JNIHandles::destroy_local(jobj); // thread is unused. 522 } 523 524 // 525 // Threads 526 // 527 528 jobject * 529 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) { 530 if (length == 0) { 531 return NULL; 532 } 533 534 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length); 535 NULL_CHECK(objArray, NULL); 536 537 for (int i=0; i<length; i++) { 538 objArray[i] = jni_reference(handles[i]); 539 } 540 return objArray; 541 } 542 543 jthread * 544 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 545 return (jthread *) new_jobjectArray(length,handles); 546 } 547 548 jthreadGroup * 549 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) { 550 return (jthreadGroup *) new_jobjectArray(length,handles); 551 } 552 553 // return the vframe on the specified thread and depth, NULL if no such frame 554 vframe* 555 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) { 556 if (!java_thread->has_last_Java_frame()) { 557 return NULL; 558 } 559 RegisterMap reg_map(java_thread); 560 vframe *vf = java_thread->last_java_vframe(®_map); 561 int d = 0; 562 while ((vf != NULL) && (d < depth)) { 563 vf = vf->java_sender(); 564 d++; 565 } 566 return vf; 567 } 568 569 570 // 571 // utilities: JNI objects 572 // 573 574 575 jclass 576 JvmtiEnvBase::get_jni_class_non_null(Klass* k) { 577 assert(k != NULL, "k != NULL"); 578 Thread *thread = Thread::current(); 579 return (jclass)jni_reference(Handle(thread, k->java_mirror())); 580 } 581 582 // 583 // Field Information 584 // 585 586 bool 587 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) { 588 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 589 return false; 590 } 591 bool found = false; 592 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 593 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 594 found = id->find_local_field(fd); 595 } else { 596 // Non-static field. The fieldID is really the offset of the field within the object. 597 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 598 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 599 } 600 return found; 601 } 602 603 // 604 // Object Monitor Information 605 // 606 607 // 608 // Count the number of objects for a lightweight monitor. The hobj 609 // parameter is object that owns the monitor so this routine will 610 // count the number of times the same object was locked by frames 611 // in java_thread. 612 // 613 jint 614 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 615 jint ret = 0; 616 if (!java_thread->has_last_Java_frame()) { 617 return ret; // no Java frames so no monitors 618 } 619 620 ResourceMark rm; 621 HandleMark hm; 622 RegisterMap reg_map(java_thread); 623 624 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL; 625 jvf = jvf->java_sender()) { 626 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 627 if (!mons->is_empty()) { 628 for (int i = 0; i < mons->length(); i++) { 629 MonitorInfo *mi = mons->at(i); 630 if (mi->owner_is_scalar_replaced()) continue; 631 632 // see if owner of the monitor is our object 633 if (mi->owner() != NULL && mi->owner() == hobj()) { 634 ret++; 635 } 636 } 637 } 638 } 639 return ret; 640 } 641 642 643 644 jvmtiError 645 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) { 646 #ifdef ASSERT 647 uint32_t debug_bits = 0; 648 #endif 649 assert((SafepointSynchronize::is_at_safepoint() || 650 java_thread->is_thread_fully_suspended(false, &debug_bits)), 651 "at safepoint or target thread is suspended"); 652 oop obj = NULL; 653 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 654 if (mon == NULL) { 655 // thread is not doing an Object.wait() call 656 mon = java_thread->current_pending_monitor(); 657 if (mon != NULL) { 658 // The thread is trying to enter() or raw_enter() an ObjectMonitor. 659 obj = (oop)mon->object(); 660 // If obj == NULL, then ObjectMonitor is raw which doesn't count 661 // as contended for this API 662 } 663 // implied else: no contended ObjectMonitor 664 } else { 665 // thread is doing an Object.wait() call 666 obj = (oop)mon->object(); 667 assert(obj != NULL, "Object.wait() should have an object"); 668 } 669 670 if (obj == NULL) { 671 *monitor_ptr = NULL; 672 } else { 673 HandleMark hm; 674 Handle hobj(Thread::current(), obj); 675 *monitor_ptr = jni_reference(calling_thread, hobj); 676 } 677 return JVMTI_ERROR_NONE; 678 } 679 680 681 jvmtiError 682 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 683 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 684 jvmtiError err = JVMTI_ERROR_NONE; 685 #ifdef ASSERT 686 uint32_t debug_bits = 0; 687 #endif 688 assert((SafepointSynchronize::is_at_safepoint() || 689 java_thread->is_thread_fully_suspended(false, &debug_bits)), 690 "at safepoint or target thread is suspended"); 691 692 if (java_thread->has_last_Java_frame()) { 693 ResourceMark rm; 694 HandleMark hm; 695 RegisterMap reg_map(java_thread); 696 697 int depth = 0; 698 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL; 699 jvf = jvf->java_sender()) { 700 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 701 // add locked objects for this frame into list 702 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1); 703 if (err != JVMTI_ERROR_NONE) { 704 return err; 705 } 706 } 707 } 708 } 709 710 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 711 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this); 712 ObjectSynchronizer::monitors_iterate(&jmc); 713 err = jmc.error(); 714 715 return err; 716 } 717 718 // Save JNI local handles for any objects that this frame owns. 719 jvmtiError 720 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread, 721 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) { 722 jvmtiError err = JVMTI_ERROR_NONE; 723 ResourceMark rm; 724 725 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 726 if (mons->is_empty()) { 727 return err; // this javaVFrame holds no monitors 728 } 729 730 HandleMark hm; 731 oop wait_obj = NULL; 732 { 733 // save object of current wait() call (if any) for later comparison 734 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 735 if (mon != NULL) { 736 wait_obj = (oop)mon->object(); 737 } 738 } 739 oop pending_obj = NULL; 740 { 741 // save object of current enter() call (if any) for later comparison 742 ObjectMonitor *mon = java_thread->current_pending_monitor(); 743 if (mon != NULL) { 744 pending_obj = (oop)mon->object(); 745 } 746 } 747 748 for (int i = 0; i < mons->length(); i++) { 749 MonitorInfo *mi = mons->at(i); 750 751 if (mi->owner_is_scalar_replaced()) continue; 752 753 oop obj = mi->owner(); 754 if (obj == NULL) { 755 // this monitor doesn't have an owning object so skip it 756 continue; 757 } 758 759 if (wait_obj == obj) { 760 // the thread is waiting on this monitor so it isn't really owned 761 continue; 762 } 763 764 if (pending_obj == obj) { 765 // the thread is pending on this monitor so it isn't really owned 766 continue; 767 } 768 769 if (owned_monitors_list->length() > 0) { 770 // Our list has at least one object on it so we have to check 771 // for recursive object locking 772 bool found = false; 773 for (int j = 0; j < owned_monitors_list->length(); j++) { 774 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 775 oop check = JNIHandles::resolve(jobj); 776 if (check == obj) { 777 found = true; // we found the object 778 break; 779 } 780 } 781 782 if (found) { 783 // already have this object so don't include it 784 continue; 785 } 786 } 787 788 // add the owning object to our list 789 jvmtiMonitorStackDepthInfo *jmsdi; 790 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 791 if (err != JVMTI_ERROR_NONE) { 792 return err; 793 } 794 Handle hobj(Thread::current(), obj); 795 jmsdi->monitor = jni_reference(calling_thread, hobj); 796 jmsdi->stack_depth = stack_depth; 797 owned_monitors_list->append(jmsdi); 798 } 799 800 return err; 801 } 802 803 jvmtiError 804 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 805 jint start_depth, jint max_count, 806 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 807 #ifdef ASSERT 808 uint32_t debug_bits = 0; 809 #endif 810 assert((SafepointSynchronize::is_at_safepoint() || 811 java_thread->is_thread_fully_suspended(false, &debug_bits)), 812 "at safepoint or target thread is suspended"); 813 int count = 0; 814 if (java_thread->has_last_Java_frame()) { 815 RegisterMap reg_map(java_thread); 816 Thread* current_thread = Thread::current(); 817 ResourceMark rm(current_thread); 818 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 819 HandleMark hm(current_thread); 820 if (start_depth != 0) { 821 if (start_depth > 0) { 822 for (int j = 0; j < start_depth && jvf != NULL; j++) { 823 jvf = jvf->java_sender(); 824 } 825 if (jvf == NULL) { 826 // start_depth is deeper than the stack depth 827 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 828 } 829 } else { // start_depth < 0 830 // we are referencing the starting depth based on the oldest 831 // part of the stack. 832 // optimize to limit the number of times that java_sender() is called 833 javaVFrame *jvf_cursor = jvf; 834 javaVFrame *jvf_prev = NULL; 835 javaVFrame *jvf_prev_prev = NULL; 836 int j = 0; 837 while (jvf_cursor != NULL) { 838 jvf_prev_prev = jvf_prev; 839 jvf_prev = jvf_cursor; 840 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) { 841 jvf_cursor = jvf_cursor->java_sender(); 842 } 843 } 844 if (j == start_depth) { 845 // previous pointer is exactly where we want to start 846 jvf = jvf_prev; 847 } else { 848 // we need to back up further to get to the right place 849 if (jvf_prev_prev == NULL) { 850 // the -start_depth is greater than the stack depth 851 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 852 } 853 // j now is the number of frames on the stack starting with 854 // jvf_prev, we start from jvf_prev_prev and move older on 855 // the stack that many, the result is -start_depth frames 856 // remaining. 857 jvf = jvf_prev_prev; 858 for (; j < 0; j++) { 859 jvf = jvf->java_sender(); 860 } 861 } 862 } 863 } 864 for (; count < max_count && jvf != NULL; count++) { 865 frame_buffer[count].method = jvf->method()->jmethod_id(); 866 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 867 jvf = jvf->java_sender(); 868 } 869 } else { 870 if (start_depth != 0) { 871 // no frames and there is a starting depth 872 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 873 } 874 } 875 *count_ptr = count; 876 return JVMTI_ERROR_NONE; 877 } 878 879 jvmtiError 880 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) { 881 assert((state != NULL), 882 "JavaThread should create JvmtiThreadState before calling this method"); 883 *count_ptr = state->count_frames(); 884 return JVMTI_ERROR_NONE; 885 } 886 887 jvmtiError 888 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 889 jmethodID* method_ptr, jlocation* location_ptr) { 890 #ifdef ASSERT 891 uint32_t debug_bits = 0; 892 #endif 893 assert((SafepointSynchronize::is_at_safepoint() || 894 java_thread->is_thread_fully_suspended(false, &debug_bits)), 895 "at safepoint or target thread is suspended"); 896 Thread* current_thread = Thread::current(); 897 ResourceMark rm(current_thread); 898 899 vframe *vf = vframeFor(java_thread, depth); 900 if (vf == NULL) { 901 return JVMTI_ERROR_NO_MORE_FRAMES; 902 } 903 904 // vframeFor should return a java frame. If it doesn't 905 // it means we've got an internal error and we return the 906 // error in product mode. In debug mode we will instead 907 // attempt to cast the vframe to a javaVFrame and will 908 // cause an assertion/crash to allow further diagnosis. 909 #ifdef PRODUCT 910 if (!vf->is_java_frame()) { 911 return JVMTI_ERROR_INTERNAL; 912 } 913 #endif 914 915 HandleMark hm(current_thread); 916 javaVFrame *jvf = javaVFrame::cast(vf); 917 Method* method = jvf->method(); 918 if (method->is_native()) { 919 *location_ptr = -1; 920 } else { 921 *location_ptr = jvf->bci(); 922 } 923 *method_ptr = method->jmethod_id(); 924 925 return JVMTI_ERROR_NONE; 926 } 927 928 929 jvmtiError 930 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 931 HandleMark hm; 932 Handle hobj; 933 934 Thread* current_thread = Thread::current(); 935 bool at_safepoint = SafepointSynchronize::is_at_safepoint(); 936 937 // Check arguments 938 { 939 oop mirror = JNIHandles::resolve_external_guard(object); 940 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 941 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 942 943 hobj = Handle(current_thread, mirror); 944 } 945 946 JavaThread *owning_thread = NULL; 947 ObjectMonitor *mon = NULL; 948 jvmtiMonitorUsage ret = { 949 NULL, 0, 0, NULL, 0, NULL 950 }; 951 952 uint32_t debug_bits = 0; 953 // first derive the object's owner and entry_count (if any) 954 { 955 // Revoke any biases before querying the mark word 956 if (at_safepoint) { 957 BiasedLocking::revoke_at_safepoint(hobj); 958 } else { 959 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread); 960 } 961 962 address owner = NULL; 963 { 964 markOop mark = hobj()->mark(); 965 966 if (!mark->has_monitor()) { 967 // this object has a lightweight monitor 968 969 if (mark->has_locker()) { 970 owner = (address)mark->locker(); // save the address of the Lock word 971 } 972 // implied else: no owner 973 } else { 974 // this object has a heavyweight monitor 975 mon = mark->monitor(); 976 977 // The owner field of a heavyweight monitor may be NULL for no 978 // owner, a JavaThread * or it may still be the address of the 979 // Lock word in a JavaThread's stack. A monitor can be inflated 980 // by a non-owning JavaThread, but only the owning JavaThread 981 // can change the owner field from the Lock word to the 982 // JavaThread * and it may not have done that yet. 983 owner = (address)mon->owner(); 984 } 985 } 986 987 if (owner != NULL) { 988 // Use current thread since function can be called from a 989 // JavaThread or the VMThread. 990 ThreadsListHandle tlh; 991 // This monitor is owned so we have to find the owning JavaThread. 992 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner); 993 // Cannot assume (owning_thread != NULL) here because this function 994 // may not have been called at a safepoint and the owning_thread 995 // might not be suspended. 996 if (owning_thread != NULL) { 997 // The monitor's owner either has to be the current thread, at safepoint 998 // or it has to be suspended. Any of these conditions will prevent both 999 // contending and waiting threads from modifying the state of 1000 // the monitor. 1001 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) { 1002 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED 1003 // will not make it back to the JVM/TI agent. The error code will 1004 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which 1005 // will retry the call via a VM_GetObjectMonitorUsage VM op. 1006 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1007 } 1008 HandleMark hm; 1009 Handle th(current_thread, owning_thread->threadObj()); 1010 ret.owner = (jthread)jni_reference(calling_thread, th); 1011 } 1012 // implied else: no owner 1013 } // ThreadsListHandle is destroyed here. 1014 1015 if (owning_thread != NULL) { // monitor is owned 1016 // The recursions field of a monitor does not reflect recursions 1017 // as lightweight locks before inflating the monitor are not included. 1018 // We have to count the number of recursive monitor entries the hard way. 1019 // We pass a handle to survive any GCs along the way. 1020 ResourceMark rm; 1021 ret.entry_count = count_locked_objects(owning_thread, hobj); 1022 } 1023 // implied else: entry_count == 0 1024 } 1025 1026 jint nWant = 0, nWait = 0; 1027 if (mon != NULL) { 1028 // this object has a heavyweight monitor 1029 nWant = mon->contentions(); // # of threads contending for monitor 1030 nWait = mon->waiters(); // # of threads in Object.wait() 1031 ret.waiter_count = nWant + nWait; 1032 ret.notify_waiter_count = nWait; 1033 } else { 1034 // this object has a lightweight monitor 1035 ret.waiter_count = 0; 1036 ret.notify_waiter_count = 0; 1037 } 1038 1039 // Allocate memory for heavyweight and lightweight monitor. 1040 jvmtiError err; 1041 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1042 if (err != JVMTI_ERROR_NONE) { 1043 return err; 1044 } 1045 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1046 (unsigned char**)&ret.notify_waiters); 1047 if (err != JVMTI_ERROR_NONE) { 1048 deallocate((unsigned char*)ret.waiters); 1049 return err; 1050 } 1051 1052 // now derive the rest of the fields 1053 if (mon != NULL) { 1054 // this object has a heavyweight monitor 1055 1056 // Number of waiters may actually be less than the waiter count. 1057 // So NULL out memory so that unused memory will be NULL. 1058 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1059 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1060 1061 if (ret.waiter_count > 0) { 1062 // we have contending and/or waiting threads 1063 HandleMark hm; 1064 // Use current thread since function can be called from a 1065 // JavaThread or the VMThread. 1066 ThreadsListHandle tlh; 1067 if (nWant > 0) { 1068 // we have contending threads 1069 ResourceMark rm; 1070 // get_pending_threads returns only java thread so we do not need to 1071 // check for non java threads. 1072 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon); 1073 if (wantList->length() < nWant) { 1074 // robustness: the pending list has gotten smaller 1075 nWant = wantList->length(); 1076 } 1077 for (int i = 0; i < nWant; i++) { 1078 JavaThread *pending_thread = wantList->at(i); 1079 // If the monitor has no owner, then a non-suspended contending 1080 // thread could potentially change the state of the monitor by 1081 // entering it. The JVM/TI spec doesn't allow this. 1082 if (owning_thread == NULL && !at_safepoint & 1083 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) { 1084 if (ret.owner != NULL) { 1085 destroy_jni_reference(calling_thread, ret.owner); 1086 } 1087 for (int j = 0; j < i; j++) { 1088 destroy_jni_reference(calling_thread, ret.waiters[j]); 1089 } 1090 deallocate((unsigned char*)ret.waiters); 1091 deallocate((unsigned char*)ret.notify_waiters); 1092 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1093 } 1094 Handle th(current_thread, pending_thread->threadObj()); 1095 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1096 } 1097 } 1098 if (nWait > 0) { 1099 // we have threads in Object.wait() 1100 int offset = nWant; // add after any contending threads 1101 ObjectWaiter *waiter = mon->first_waiter(); 1102 for (int i = 0, j = 0; i < nWait; i++) { 1103 if (waiter == NULL) { 1104 // robustness: the waiting list has gotten smaller 1105 nWait = j; 1106 break; 1107 } 1108 Thread *t = mon->thread_of_waiter(waiter); 1109 if (t != NULL && t->is_Java_thread()) { 1110 JavaThread *wjava_thread = (JavaThread *)t; 1111 // If the thread was found on the ObjectWaiter list, then 1112 // it has not been notified. This thread can't change the 1113 // state of the monitor so it doesn't need to be suspended. 1114 Handle th(current_thread, wjava_thread->threadObj()); 1115 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th); 1116 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th); 1117 } 1118 waiter = mon->next_waiter(waiter); 1119 } 1120 } 1121 } // ThreadsListHandle is destroyed here. 1122 1123 // Adjust count. nWant and nWait count values may be less than original. 1124 ret.waiter_count = nWant + nWait; 1125 ret.notify_waiter_count = nWait; 1126 } else { 1127 // this object has a lightweight monitor and we have nothing more 1128 // to do here because the defaults are just fine. 1129 } 1130 1131 // we don't update return parameter unless everything worked 1132 *info_ptr = ret; 1133 1134 return JVMTI_ERROR_NONE; 1135 } 1136 1137 ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1138 _env = env; 1139 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true); 1140 _failed = false; 1141 } 1142 ResourceTracker::~ResourceTracker() { 1143 if (_failed) { 1144 for (int i=0; i<_allocations->length(); i++) { 1145 _env->deallocate(_allocations->at(i)); 1146 } 1147 } 1148 delete _allocations; 1149 } 1150 1151 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1152 unsigned char *ptr; 1153 jvmtiError err = _env->allocate(size, &ptr); 1154 if (err == JVMTI_ERROR_NONE) { 1155 _allocations->append(ptr); 1156 *mem_ptr = ptr; 1157 } else { 1158 *mem_ptr = NULL; 1159 _failed = true; 1160 } 1161 return err; 1162 } 1163 1164 unsigned char* ResourceTracker::allocate(jlong size) { 1165 unsigned char* ptr; 1166 allocate(size, &ptr); 1167 return ptr; 1168 } 1169 1170 char* ResourceTracker::strdup(const char* str) { 1171 char *dup_str = (char*)allocate(strlen(str)+1); 1172 if (dup_str != NULL) { 1173 strcpy(dup_str, str); 1174 } 1175 return dup_str; 1176 } 1177 1178 struct StackInfoNode { 1179 struct StackInfoNode *next; 1180 jvmtiStackInfo info; 1181 }; 1182 1183 // Create a jvmtiStackInfo inside a linked list node and create a 1184 // buffer for the frame information, both allocated as resource objects. 1185 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1186 // Note that either or both of thr and thread_oop 1187 // may be null if the thread is new or has exited. 1188 void 1189 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1190 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1191 1192 jint state = 0; 1193 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1194 jvmtiStackInfo *infop = &(node->info); 1195 node->next = head(); 1196 set_head(node); 1197 infop->frame_count = 0; 1198 infop->thread = jt; 1199 1200 if (thread_oop != NULL) { 1201 // get most state bits 1202 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 1203 } 1204 1205 if (thr != NULL) { // add more state bits if there is a JavaThead to query 1206 // same as is_being_ext_suspended() but without locking 1207 if (thr->is_ext_suspended() || thr->is_external_suspend()) { 1208 state |= JVMTI_THREAD_STATE_SUSPENDED; 1209 } 1210 JavaThreadState jts = thr->thread_state(); 1211 if (jts == _thread_in_native) { 1212 state |= JVMTI_THREAD_STATE_IN_NATIVE; 1213 } 1214 OSThread* osThread = thr->osthread(); 1215 if (osThread != NULL && osThread->interrupted()) { 1216 state |= JVMTI_THREAD_STATE_INTERRUPTED; 1217 } 1218 } 1219 infop->state = state; 1220 1221 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1222 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1223 env()->get_stack_trace(thr, 0, max_frame_count(), 1224 infop->frame_buffer, &(infop->frame_count)); 1225 } else { 1226 infop->frame_buffer = NULL; 1227 infop->frame_count = 0; 1228 } 1229 _frame_count_total += infop->frame_count; 1230 } 1231 1232 // Based on the stack information in the linked list, allocate memory 1233 // block to return and fill it from the info in the linked list. 1234 void 1235 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) { 1236 // do I need to worry about alignment issues? 1237 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1238 + _frame_count_total * sizeof(jvmtiFrameInfo); 1239 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1240 1241 // pointers to move through the newly allocated space as it is filled in 1242 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1243 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1244 1245 // copy information in resource area into allocated buffer 1246 // insert stack info backwards since linked list is backwards 1247 // insert frame info forwards 1248 // walk the StackInfoNodes 1249 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) { 1250 jint frame_count = sin->info.frame_count; 1251 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1252 --si; 1253 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1254 if (frames_size == 0) { 1255 si->frame_buffer = NULL; 1256 } else { 1257 memcpy(fi, sin->info.frame_buffer, frames_size); 1258 si->frame_buffer = fi; // point to the new allocated copy of the frames 1259 fi += frame_count; 1260 } 1261 } 1262 assert(si == _stack_info, "the last copied stack info must be the first record"); 1263 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1264 "the last copied frame info must be the last record"); 1265 } 1266 1267 1268 void 1269 VM_GetThreadListStackTraces::doit() { 1270 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1271 1272 ResourceMark rm; 1273 ThreadsListHandle tlh; 1274 for (int i = 0; i < _thread_count; ++i) { 1275 jthread jt = _thread_list[i]; 1276 JavaThread* java_thread = NULL; 1277 oop thread_oop = NULL; 1278 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop); 1279 if (err != JVMTI_ERROR_NONE) { 1280 // We got an error code so we don't have a JavaThread *, but 1281 // only return an error from here if we didn't get a valid 1282 // thread_oop. 1283 if (thread_oop == NULL) { 1284 set_result(err); 1285 return; 1286 } 1287 // We have a valid thread_oop. 1288 } 1289 fill_frames(jt, java_thread, thread_oop); 1290 } 1291 allocate_and_fill_stacks(_thread_count); 1292 } 1293 1294 void 1295 VM_GetAllStackTraces::doit() { 1296 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1297 1298 ResourceMark rm; 1299 _final_thread_count = 0; 1300 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 1301 oop thread_oop = jt->threadObj(); 1302 if (thread_oop != NULL && 1303 !jt->is_exiting() && 1304 java_lang_Thread::is_alive(thread_oop) && 1305 !jt->is_hidden_from_external_view()) { 1306 ++_final_thread_count; 1307 // Handle block of the calling thread is used to create local refs. 1308 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1309 jt, thread_oop); 1310 } 1311 } 1312 allocate_and_fill_stacks(_final_thread_count); 1313 } 1314 1315 // Verifies that the top frame is a java frame in an expected state. 1316 // Deoptimizes frame if needed. 1317 // Checks that the frame method signature matches the return type (tos). 1318 // HandleMark must be defined in the caller only. 1319 // It is to keep a ret_ob_h handle alive after return to the caller. 1320 jvmtiError 1321 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread, 1322 jvalue value, TosState tos, Handle* ret_ob_h) { 1323 ResourceMark rm(current_thread); 1324 1325 vframe *vf = vframeFor(java_thread, 0); 1326 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES); 1327 1328 javaVFrame *jvf = (javaVFrame*) vf; 1329 if (!vf->is_java_frame() || jvf->method()->is_native()) { 1330 return JVMTI_ERROR_OPAQUE_FRAME; 1331 } 1332 1333 // If the frame is a compiled one, need to deoptimize it. 1334 if (vf->is_compiled_frame()) { 1335 if (!vf->fr().can_be_deoptimized()) { 1336 return JVMTI_ERROR_OPAQUE_FRAME; 1337 } 1338 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 1339 } 1340 1341 // Get information about method return type 1342 Symbol* signature = jvf->method()->signature(); 1343 1344 ResultTypeFinder rtf(signature); 1345 TosState fr_tos = as_TosState(rtf.type()); 1346 if (fr_tos != tos) { 1347 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) { 1348 return JVMTI_ERROR_TYPE_MISMATCH; 1349 } 1350 } 1351 1352 // Check that the jobject class matches the return type signature. 1353 jobject jobj = value.l; 1354 if (tos == atos && jobj != NULL) { // NULL reference is allowed 1355 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj)); 1356 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 1357 Klass* ob_k = ob_h()->klass(); 1358 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT); 1359 1360 // Method return type signature. 1361 char* ty_sign = 1 + strchr(signature->as_C_string(), ')'); 1362 1363 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) { 1364 return JVMTI_ERROR_TYPE_MISMATCH; 1365 } 1366 *ret_ob_h = ob_h; 1367 } 1368 return JVMTI_ERROR_NONE; 1369 } /* end check_top_frame */ 1370 1371 1372 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 1373 // Main difference is on the last stage in the interpreter. 1374 // The PopFrame stops method execution to continue execution 1375 // from the same method call instruction. 1376 // The ForceEarlyReturn forces return from method so the execution 1377 // continues at the bytecode following the method call. 1378 1379 // Threads_lock NOT held, java_thread not protected by lock 1380 // java_thread - pre-checked 1381 1382 jvmtiError 1383 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) { 1384 JavaThread* current_thread = JavaThread::current(); 1385 HandleMark hm(current_thread); 1386 uint32_t debug_bits = 0; 1387 1388 // retrieve or create the state 1389 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 1390 if (state == NULL) { 1391 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1392 } 1393 1394 // Check if java_thread is fully suspended 1395 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) { 1396 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1397 } 1398 1399 // Check to see if a ForceEarlyReturn was already in progress 1400 if (state->is_earlyret_pending()) { 1401 // Probably possible for JVMTI clients to trigger this, but the 1402 // JPDA backend shouldn't allow this to happen 1403 return JVMTI_ERROR_INTERNAL; 1404 } 1405 { 1406 // The same as for PopFrame. Workaround bug: 1407 // 4812902: popFrame hangs if the method is waiting at a synchronize 1408 // Catch this condition and return an error to avoid hanging. 1409 // Now JVMTI spec allows an implementation to bail out with an opaque 1410 // frame error. 1411 OSThread* osThread = java_thread->osthread(); 1412 if (osThread->get_state() == MONITOR_WAIT) { 1413 return JVMTI_ERROR_OPAQUE_FRAME; 1414 } 1415 } 1416 Handle ret_ob_h; 1417 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h); 1418 if (err != JVMTI_ERROR_NONE) { 1419 return err; 1420 } 1421 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL, 1422 "return object oop must not be NULL if jobject is not NULL"); 1423 1424 // Update the thread state to reflect that the top frame must be 1425 // forced to return. 1426 // The current frame will be returned later when the suspended 1427 // thread is resumed and right before returning from VM to Java. 1428 // (see call_VM_base() in assembler_<cpu>.cpp). 1429 1430 state->set_earlyret_pending(); 1431 state->set_earlyret_oop(ret_ob_h()); 1432 state->set_earlyret_value(value, tos); 1433 1434 // Set pending step flag for this early return. 1435 // It is cleared when next step event is posted. 1436 state->set_pending_step_for_earlyret(); 1437 1438 return JVMTI_ERROR_NONE; 1439 } /* end force_early_return */ 1440 1441 void 1442 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 1443 if ( _error != JVMTI_ERROR_NONE) { 1444 // Error occurred in previous iteration so no need to add 1445 // to the list. 1446 return; 1447 } 1448 if (mon->owner() == _java_thread ) { 1449 // Filter out on stack monitors collected during stack walk. 1450 oop obj = (oop)mon->object(); 1451 bool found = false; 1452 for (int j = 0; j < _owned_monitors_list->length(); j++) { 1453 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 1454 oop check = JNIHandles::resolve(jobj); 1455 if (check == obj) { 1456 // On stack monitor already collected during the stack walk. 1457 found = true; 1458 break; 1459 } 1460 } 1461 if (found == false) { 1462 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 1463 jvmtiError err; 1464 jvmtiMonitorStackDepthInfo *jmsdi; 1465 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1466 if (err != JVMTI_ERROR_NONE) { 1467 _error = err; 1468 return; 1469 } 1470 Handle hobj(Thread::current(), obj); 1471 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 1472 // stack depth is unknown for this monitor. 1473 jmsdi->stack_depth = -1; 1474 _owned_monitors_list->append(jmsdi); 1475 } 1476 } 1477 } 1478 1479 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL; 1480 1481 jvmtiError 1482 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) { 1483 ResourceMark rm; 1484 MutexLocker ml(Module_lock); 1485 1486 _tbl = new GrowableArray<OopHandle>(77); 1487 if (_tbl == NULL) { 1488 return JVMTI_ERROR_OUT_OF_MEMORY; 1489 } 1490 1491 // Iterate over all the modules loaded to the system. 1492 ClassLoaderDataGraph::modules_do(&do_module); 1493 1494 jint len = _tbl->length(); 1495 guarantee(len > 0, "at least one module must be present"); 1496 1497 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject))); 1498 if (array == NULL) { 1499 return JVMTI_ERROR_OUT_OF_MEMORY; 1500 } 1501 for (jint idx = 0; idx < len; idx++) { 1502 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve()); 1503 } 1504 _tbl = NULL; 1505 *modules_ptr = array; 1506 *module_count_ptr = len; 1507 return JVMTI_ERROR_NONE; 1508 } 1509 1510 void 1511 VM_UpdateForPopTopFrame::doit() { 1512 JavaThread* jt = _state->get_thread(); 1513 ThreadsListHandle tlh; 1514 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1515 _state->update_for_pop_top_frame(); 1516 } else { 1517 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1518 } 1519 } 1520 1521 void 1522 VM_SetFramePop::doit() { 1523 JavaThread* jt = _state->get_thread(); 1524 ThreadsListHandle tlh; 1525 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1526 int frame_number = _state->count_frames() - _depth; 1527 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number); 1528 } else { 1529 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1530 } 1531 } 1532 1533 void 1534 VM_GetOwnedMonitorInfo::doit() { 1535 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1536 ThreadsListHandle tlh; 1537 if (_java_thread != NULL && tlh.includes(_java_thread) 1538 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1539 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread, 1540 _owned_monitors_list); 1541 } 1542 } 1543 1544 void 1545 VM_GetCurrentContendedMonitor::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_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr); 1551 } 1552 } 1553 1554 void 1555 VM_GetStackTrace::doit() { 1556 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1557 ThreadsListHandle tlh; 1558 if (_java_thread != NULL && tlh.includes(_java_thread) 1559 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1560 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread, 1561 _start_depth, _max_count, 1562 _frame_buffer, _count_ptr); 1563 } 1564 } 1565 1566 void 1567 VM_GetFrameCount::doit() { 1568 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1569 JavaThread* jt = _state->get_thread(); 1570 ThreadsListHandle tlh; 1571 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) { 1572 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr); 1573 } 1574 } 1575 1576 void 1577 VM_GetFrameLocation::doit() { 1578 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 1579 ThreadsListHandle tlh; 1580 if (_java_thread != NULL && tlh.includes(_java_thread) 1581 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) { 1582 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth, 1583 _method_ptr, _location_ptr); 1584 } 1585 }