jvmtiEnvBase.cpp revision 2062:3582bf76420e
1/* 2 * Copyright (c) 2003, 2010, 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 "oops/objArrayKlass.hpp" 29#include "oops/objArrayOop.hpp" 30#include "prims/jvmtiEnvBase.hpp" 31#include "prims/jvmtiEventController.inline.hpp" 32#include "prims/jvmtiExtensions.hpp" 33#include "prims/jvmtiImpl.hpp" 34#include "prims/jvmtiManageCapabilities.hpp" 35#include "prims/jvmtiTagMap.hpp" 36#include "prims/jvmtiThreadState.inline.hpp" 37#include "runtime/biasedLocking.hpp" 38#include "runtime/deoptimization.hpp" 39#include "runtime/interfaceSupport.hpp" 40#include "runtime/jfieldIDWorkaround.hpp" 41#include "runtime/objectMonitor.hpp" 42#include "runtime/objectMonitor.inline.hpp" 43#include "runtime/signature.hpp" 44#include "runtime/vframe.hpp" 45#include "runtime/vframe_hp.hpp" 46#include "runtime/vmThread.hpp" 47#include "runtime/vm_operations.hpp" 48 49/////////////////////////////////////////////////////////////// 50// 51// JvmtiEnvBase 52// 53 54JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL; 55 56bool JvmtiEnvBase::_globally_initialized = false; 57volatile bool JvmtiEnvBase::_needs_clean_up = false; 58 59jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 60 61volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 62 63extern jvmtiInterface_1_ jvmti_Interface; 64extern jvmtiInterface_1_ jvmtiTrace_Interface; 65 66 67// perform initializations that must occur before any JVMTI environments 68// are released but which should only be initialized once (no matter 69// how many environments are created). 70void 71JvmtiEnvBase::globally_initialize() { 72 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 73 assert(_globally_initialized == false, "bad call"); 74 75 JvmtiManageCapabilities::initialize(); 76 77#ifndef JVMTI_KERNEL 78 // register extension functions and events 79 JvmtiExtensions::register_extensions(); 80#endif // !JVMTI_KERNEL 81 82#ifdef JVMTI_TRACE 83 JvmtiTrace::initialize(); 84#endif 85 86 _globally_initialized = true; 87} 88 89 90void 91JvmtiEnvBase::initialize() { 92 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 93 94 // Add this environment to the end of the environment list (order is important) 95 { 96 // This block of code must not contain any safepoints, as list deallocation 97 // (which occurs at a safepoint) cannot occur simultaneously with this list 98 // addition. Note: No_Safepoint_Verifier cannot, currently, be used before 99 // threads exist. 100 JvmtiEnvIterator it; 101 JvmtiEnvBase *previous_env = NULL; 102 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 103 previous_env = env; 104 } 105 if (previous_env == NULL) { 106 _head_environment = this; 107 } else { 108 previous_env->set_next_environment(this); 109 } 110 } 111 112 if (_globally_initialized == false) { 113 globally_initialize(); 114 } 115} 116 117 118bool 119JvmtiEnvBase::is_valid() { 120 jint value = 0; 121 122 // This object might not be a JvmtiEnvBase so we can't assume 123 // the _magic field is properly aligned. Get the value in a safe 124 // way and then check against JVMTI_MAGIC. 125 126 switch (sizeof(_magic)) { 127 case 2: 128 value = Bytes::get_native_u2((address)&_magic); 129 break; 130 131 case 4: 132 value = Bytes::get_native_u4((address)&_magic); 133 break; 134 135 case 8: 136 value = Bytes::get_native_u8((address)&_magic); 137 break; 138 139 default: 140 guarantee(false, "_magic field is an unexpected size"); 141 } 142 143 return value == JVMTI_MAGIC; 144} 145 146 147bool 148JvmtiEnvBase::use_version_1_0_semantics() { 149 int major, minor, micro; 150 151 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 152 return major == 1 && minor == 0; // micro version doesn't matter here 153} 154 155 156bool 157JvmtiEnvBase::use_version_1_1_semantics() { 158 int major, minor, micro; 159 160 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 161 return major == 1 && minor == 1; // micro version doesn't matter here 162} 163 164bool 165JvmtiEnvBase::use_version_1_2_semantics() { 166 int major, minor, micro; 167 168 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 169 return major == 1 && minor == 2; // micro version doesn't matter here 170} 171 172 173JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 174 _version = version; 175 _env_local_storage = NULL; 176 _tag_map = NULL; 177 _native_method_prefix_count = 0; 178 _native_method_prefixes = NULL; 179 _next = NULL; 180 _class_file_load_hook_ever_enabled = false; 181 182 // Moot since ClassFileLoadHook not yet enabled. 183 // But "true" will give a more predictable ClassFileLoadHook behavior 184 // for environment creation during ClassFileLoadHook. 185 _is_retransformable = true; 186 187 // all callbacks initially NULL 188 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks)); 189 190 // all capabilities initially off 191 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 192 193 // all prohibited capabilities initially off 194 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 195 196 _magic = JVMTI_MAGIC; 197 198 JvmtiEventController::env_initialize((JvmtiEnv*)this); 199 200#ifdef JVMTI_TRACE 201 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface; 202#else 203 _jvmti_external.functions = &jvmti_Interface; 204#endif 205} 206 207 208void 209JvmtiEnvBase::dispose() { 210 211#ifdef JVMTI_TRACE 212 JvmtiTrace::shutdown(); 213#endif 214 215 // Dispose of event info and let the event controller call us back 216 // in a locked state (env_dispose, below) 217 JvmtiEventController::env_dispose(this); 218} 219 220void 221JvmtiEnvBase::env_dispose() { 222 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 223 224 // We have been entered with all events disabled on this environment. 225 // A race to re-enable events (by setting callbacks) is prevented by 226 // checking for a valid environment when setting callbacks (while 227 // holding the JvmtiThreadState_lock). 228 229 // Mark as invalid. 230 _magic = DISPOSED_MAGIC; 231 232 // Relinquish all capabilities. 233 jvmtiCapabilities *caps = get_capabilities(); 234 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 235 236 // Same situation as with events (see above) 237 set_native_method_prefixes(0, NULL); 238 239#ifndef JVMTI_KERNEL 240 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 241 set_tag_map(NULL); 242 // A tag map can be big, deallocate it now 243 if (tag_map_to_deallocate != NULL) { 244 delete tag_map_to_deallocate; 245 } 246#endif // !JVMTI_KERNEL 247 248 _needs_clean_up = true; 249} 250 251 252JvmtiEnvBase::~JvmtiEnvBase() { 253 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 254 255 // There is a small window of time during which the tag map of a 256 // disposed environment could have been reallocated. 257 // Make sure it is gone. 258#ifndef JVMTI_KERNEL 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#endif // !JVMTI_KERNEL 266 267 _magic = BAD_MAGIC; 268} 269 270 271void 272JvmtiEnvBase::periodic_clean_up() { 273 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 274 275 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 276 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 277 JvmtiThreadState::periodic_clean_up(); 278 279 // Unlink all invalid environments from the list of environments 280 // and deallocate them 281 JvmtiEnvIterator it; 282 JvmtiEnvBase* previous_env = NULL; 283 JvmtiEnvBase* env = it.first(); 284 while (env != NULL) { 285 if (env->is_valid()) { 286 previous_env = env; 287 env = it.next(env); 288 } else { 289 // This one isn't valid, remove it from the list and deallocate it 290 JvmtiEnvBase* defunct_env = env; 291 env = it.next(env); 292 if (previous_env == NULL) { 293 _head_environment = env; 294 } else { 295 previous_env->set_next_environment(env); 296 } 297 delete defunct_env; 298 } 299 } 300 301} 302 303 304void 305JvmtiEnvBase::check_for_periodic_clean_up() { 306 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 307 308 class ThreadInsideIterationClosure: public ThreadClosure { 309 private: 310 bool _inside; 311 public: 312 ThreadInsideIterationClosure() : _inside(false) {}; 313 314 void do_thread(Thread* thread) { 315 _inside |= thread->is_inside_jvmti_env_iteration(); 316 } 317 318 bool is_inside_jvmti_env_iteration() { 319 return _inside; 320 } 321 }; 322 323 if (_needs_clean_up) { 324 // Check if we are currently iterating environment, 325 // deallocation should not occur if we are 326 ThreadInsideIterationClosure tiic; 327 Threads::threads_do(&tiic); 328 if (!tiic.is_inside_jvmti_env_iteration() && 329 !is_inside_dying_thread_env_iteration()) { 330 _needs_clean_up = false; 331 JvmtiEnvBase::periodic_clean_up(); 332 } 333 } 334} 335 336 337void 338JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 339 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 340 "sanity check"); 341 342 if (!_class_file_load_hook_ever_enabled) { 343 _class_file_load_hook_ever_enabled = true; 344 345 if (get_capabilities()->can_retransform_classes) { 346 _is_retransformable = true; 347 } else { 348 _is_retransformable = false; 349 350 // cannot add retransform capability after ClassFileLoadHook has been enabled 351 get_prohibited_capabilities()->can_retransform_classes = 1; 352 } 353 } 354} 355 356 357void 358JvmtiEnvBase::record_class_file_load_hook_enabled() { 359 if (!_class_file_load_hook_ever_enabled) { 360 if (Threads::number_of_threads() == 0) { 361 record_first_time_class_file_load_hook_enabled(); 362 } else { 363 MutexLocker mu(JvmtiThreadState_lock); 364 record_first_time_class_file_load_hook_enabled(); 365 } 366 } 367} 368 369 370jvmtiError 371JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 372 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 373 "sanity check"); 374 375 int old_prefix_count = get_native_method_prefix_count(); 376 char **old_prefixes = get_native_method_prefixes(); 377 378 // allocate and install the new prefixex 379 if (prefix_count == 0 || !is_valid()) { 380 _native_method_prefix_count = 0; 381 _native_method_prefixes = NULL; 382 } else { 383 // there are prefixes, allocate an array to hold them, and fill it 384 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*)); 385 if (new_prefixes == NULL) { 386 return JVMTI_ERROR_OUT_OF_MEMORY; 387 } 388 for (int i = 0; i < prefix_count; i++) { 389 char* prefix = prefixes[i]; 390 if (prefix == NULL) { 391 for (int j = 0; j < (i-1); j++) { 392 os::free(new_prefixes[j]); 393 } 394 os::free(new_prefixes); 395 return JVMTI_ERROR_NULL_POINTER; 396 } 397 prefix = os::strdup(prefixes[i]); 398 if (prefix == NULL) { 399 for (int j = 0; j < (i-1); j++) { 400 os::free(new_prefixes[j]); 401 } 402 os::free(new_prefixes); 403 return JVMTI_ERROR_OUT_OF_MEMORY; 404 } 405 new_prefixes[i] = prefix; 406 } 407 _native_method_prefix_count = prefix_count; 408 _native_method_prefixes = new_prefixes; 409 } 410 411 // now that we know the new prefixes have been successfully installed we can 412 // safely remove the old ones 413 if (old_prefix_count != 0) { 414 for (int i = 0; i < old_prefix_count; i++) { 415 os::free(old_prefixes[i]); 416 } 417 os::free(old_prefixes); 418 } 419 420 return JVMTI_ERROR_NONE; 421} 422 423 424// Collect all the prefixes which have been set in any JVM TI environments 425// by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 426// order of environments and the order of prefixes within each environment. 427// Return in a resource allocated array. 428char** 429JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 430 assert(Threads::number_of_threads() == 0 || 431 SafepointSynchronize::is_at_safepoint() || 432 JvmtiThreadState_lock->is_locked(), 433 "sanity check"); 434 435 int total_count = 0; 436 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 437 438 JvmtiEnvIterator it; 439 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { 440 int prefix_count = env->get_native_method_prefix_count(); 441 char** prefixes = env->get_native_method_prefixes(); 442 for (int j = 0; j < prefix_count; j++) { 443 // retrieve a prefix and so that it is safe against asynchronous changes 444 // copy it into the resource area 445 char* prefix = prefixes[j]; 446 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 447 strcpy(prefix_copy, prefix); 448 prefix_array->at_put_grow(total_count++, prefix_copy); 449 } 450 } 451 452 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 453 char** p = all_prefixes; 454 for (int i = 0; i < total_count; ++i) { 455 *p++ = prefix_array->at(i); 456 } 457 *count_ptr = total_count; 458 return all_prefixes; 459} 460 461void 462JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 463 jint size_of_callbacks) { 464 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 465 466 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 467 468 // clear in either case to be sure we got any gap between sizes 469 memset(&_event_callbacks, 0, byte_cnt); 470 471 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 472 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 473 // occurs after the boiler-plate environment check and before the lock is acquired. 474 if (callbacks != NULL && is_valid()) { 475 if (size_of_callbacks < (jint)byte_cnt) { 476 byte_cnt = size_of_callbacks; 477 } 478 memcpy(&_event_callbacks, callbacks, byte_cnt); 479 } 480} 481 482// Called from JVMTI entry points which perform stack walking. If the 483// associated JavaThread is the current thread, then wait_for_suspend 484// is not used. Otherwise, it determines if we should wait for the 485// "other" thread to complete external suspension. (NOTE: in future 486// releases the suspension mechanism should be reimplemented so this 487// is not necessary.) 488// 489bool 490JvmtiEnvBase::is_thread_fully_suspended(JavaThread* thr, bool wait_for_suspend, uint32_t *bits) { 491 // "other" threads require special handling 492 if (thr != JavaThread::current()) { 493 if (wait_for_suspend) { 494 // We are allowed to wait for the external suspend to complete 495 // so give the other thread a chance to get suspended. 496 if (!thr->wait_for_ext_suspend_completion(SuspendRetryCount, 497 SuspendRetryDelay, bits)) { 498 // didn't make it so let the caller know 499 return false; 500 } 501 } 502 // We aren't allowed to wait for the external suspend to complete 503 // so if the other thread isn't externally suspended we need to 504 // let the caller know. 505 else if (!thr->is_ext_suspend_completed_with_lock(bits)) { 506 return false; 507 } 508 } 509 510 return true; 511} 512 513 514// In the fullness of time, all users of the method should instead 515// directly use allocate, besides being cleaner and faster, this will 516// mean much better out of memory handling 517unsigned char * 518JvmtiEnvBase::jvmtiMalloc(jlong size) { 519 unsigned char* mem; 520 jvmtiError result = allocate(size, &mem); 521 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 522 return mem; 523} 524 525 526// 527// Threads 528// 529 530jobject * 531JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) { 532 if (length == 0) { 533 return NULL; 534 } 535 536 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length); 537 NULL_CHECK(objArray, NULL); 538 539 for (int i=0; i<length; i++) { 540 objArray[i] = jni_reference(handles[i]); 541 } 542 return objArray; 543} 544 545jthread * 546JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 547 return (jthread *) new_jobjectArray(length,handles); 548} 549 550jthreadGroup * 551JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) { 552 return (jthreadGroup *) new_jobjectArray(length,handles); 553} 554 555 556JavaThread * 557JvmtiEnvBase::get_JavaThread(jthread jni_thread) { 558 oop t = JNIHandles::resolve_external_guard(jni_thread); 559 if (t == NULL || !t->is_a(SystemDictionary::Thread_klass())) { 560 return NULL; 561 } 562 // The following returns NULL if the thread has not yet run or is in 563 // process of exiting 564 return java_lang_Thread::thread(t); 565} 566 567 568// update the access_flags for the field in the klass 569void 570JvmtiEnvBase::update_klass_field_access_flag(fieldDescriptor *fd) { 571 instanceKlass* ik = instanceKlass::cast(fd->field_holder()); 572 typeArrayOop fields = ik->fields(); 573 fields->ushort_at_put(fd->index(), (jushort)fd->access_flags().as_short()); 574} 575 576 577// return the vframe on the specified thread and depth, NULL if no such frame 578vframe* 579JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) { 580 if (!java_thread->has_last_Java_frame()) { 581 return NULL; 582 } 583 RegisterMap reg_map(java_thread); 584 vframe *vf = java_thread->last_java_vframe(®_map); 585 int d = 0; 586 while ((vf != NULL) && (d < depth)) { 587 vf = vf->java_sender(); 588 d++; 589 } 590 return vf; 591} 592 593 594// 595// utilities: JNI objects 596// 597 598 599jclass 600JvmtiEnvBase::get_jni_class_non_null(klassOop k) { 601 assert(k != NULL, "k != NULL"); 602 return (jclass)jni_reference(Klass::cast(k)->java_mirror()); 603} 604 605#ifndef JVMTI_KERNEL 606 607// 608// Field Information 609// 610 611bool 612JvmtiEnvBase::get_field_descriptor(klassOop k, jfieldID field, fieldDescriptor* fd) { 613 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 614 return false; 615 } 616 bool found = false; 617 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 618 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 619 int offset = id->offset(); 620 klassOop holder = id->holder(); 621 found = instanceKlass::cast(holder)->find_local_field_from_offset(offset, true, fd); 622 } else { 623 // Non-static field. The fieldID is really the offset of the field within the object. 624 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 625 found = instanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 626 } 627 return found; 628} 629 630// 631// Object Monitor Information 632// 633 634// 635// Count the number of objects for a lightweight monitor. The hobj 636// parameter is object that owns the monitor so this routine will 637// count the number of times the same object was locked by frames 638// in java_thread. 639// 640jint 641JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 642 jint ret = 0; 643 if (!java_thread->has_last_Java_frame()) { 644 return ret; // no Java frames so no monitors 645 } 646 647 ResourceMark rm; 648 HandleMark hm; 649 RegisterMap reg_map(java_thread); 650 651 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL; 652 jvf = jvf->java_sender()) { 653 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 654 if (!mons->is_empty()) { 655 for (int i = 0; i < mons->length(); i++) { 656 MonitorInfo *mi = mons->at(i); 657 if (mi->owner_is_scalar_replaced()) continue; 658 659 // see if owner of the monitor is our object 660 if (mi->owner() != NULL && mi->owner() == hobj()) { 661 ret++; 662 } 663 } 664 } 665 } 666 return ret; 667} 668 669 670 671jvmtiError 672JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) { 673#ifdef ASSERT 674 uint32_t debug_bits = 0; 675#endif 676 assert((SafepointSynchronize::is_at_safepoint() || 677 is_thread_fully_suspended(java_thread, false, &debug_bits)), 678 "at safepoint or target thread is suspended"); 679 oop obj = NULL; 680 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 681 if (mon == NULL) { 682 // thread is not doing an Object.wait() call 683 mon = java_thread->current_pending_monitor(); 684 if (mon != NULL) { 685 // The thread is trying to enter() or raw_enter() an ObjectMonitor. 686 obj = (oop)mon->object(); 687 // If obj == NULL, then ObjectMonitor is raw which doesn't count 688 // as contended for this API 689 } 690 // implied else: no contended ObjectMonitor 691 } else { 692 // thread is doing an Object.wait() call 693 obj = (oop)mon->object(); 694 assert(obj != NULL, "Object.wait() should have an object"); 695 } 696 697 if (obj == NULL) { 698 *monitor_ptr = NULL; 699 } else { 700 HandleMark hm; 701 Handle hobj(obj); 702 *monitor_ptr = jni_reference(calling_thread, hobj); 703 } 704 return JVMTI_ERROR_NONE; 705} 706 707 708jvmtiError 709JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 710 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 711 jvmtiError err = JVMTI_ERROR_NONE; 712#ifdef ASSERT 713 uint32_t debug_bits = 0; 714#endif 715 assert((SafepointSynchronize::is_at_safepoint() || 716 is_thread_fully_suspended(java_thread, false, &debug_bits)), 717 "at safepoint or target thread is suspended"); 718 719 if (java_thread->has_last_Java_frame()) { 720 ResourceMark rm; 721 HandleMark hm; 722 RegisterMap reg_map(java_thread); 723 724 int depth = 0; 725 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL; 726 jvf = jvf->java_sender()) { 727 if (depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 728 // add locked objects for this frame into list 729 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1); 730 if (err != JVMTI_ERROR_NONE) { 731 return err; 732 } 733 } 734 } 735 } 736 737 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 738 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this); 739 ObjectSynchronizer::monitors_iterate(&jmc); 740 err = jmc.error(); 741 742 return err; 743} 744 745// Save JNI local handles for any objects that this frame owns. 746jvmtiError 747JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread, 748 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) { 749 jvmtiError err = JVMTI_ERROR_NONE; 750 ResourceMark rm; 751 752 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 753 if (mons->is_empty()) { 754 return err; // this javaVFrame holds no monitors 755 } 756 757 HandleMark hm; 758 oop wait_obj = NULL; 759 { 760 // save object of current wait() call (if any) for later comparison 761 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 762 if (mon != NULL) { 763 wait_obj = (oop)mon->object(); 764 } 765 } 766 oop pending_obj = NULL; 767 { 768 // save object of current enter() call (if any) for later comparison 769 ObjectMonitor *mon = java_thread->current_pending_monitor(); 770 if (mon != NULL) { 771 pending_obj = (oop)mon->object(); 772 } 773 } 774 775 for (int i = 0; i < mons->length(); i++) { 776 MonitorInfo *mi = mons->at(i); 777 778 if (mi->owner_is_scalar_replaced()) continue; 779 780 oop obj = mi->owner(); 781 if (obj == NULL) { 782 // this monitor doesn't have an owning object so skip it 783 continue; 784 } 785 786 if (wait_obj == obj) { 787 // the thread is waiting on this monitor so it isn't really owned 788 continue; 789 } 790 791 if (pending_obj == obj) { 792 // the thread is pending on this monitor so it isn't really owned 793 continue; 794 } 795 796 if (owned_monitors_list->length() > 0) { 797 // Our list has at least one object on it so we have to check 798 // for recursive object locking 799 bool found = false; 800 for (int j = 0; j < owned_monitors_list->length(); j++) { 801 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 802 oop check = JNIHandles::resolve(jobj); 803 if (check == obj) { 804 found = true; // we found the object 805 break; 806 } 807 } 808 809 if (found) { 810 // already have this object so don't include it 811 continue; 812 } 813 } 814 815 // add the owning object to our list 816 jvmtiMonitorStackDepthInfo *jmsdi; 817 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 818 if (err != JVMTI_ERROR_NONE) { 819 return err; 820 } 821 Handle hobj(obj); 822 jmsdi->monitor = jni_reference(calling_thread, hobj); 823 jmsdi->stack_depth = stack_depth; 824 owned_monitors_list->append(jmsdi); 825 } 826 827 return err; 828} 829 830jvmtiError 831JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 832 jint start_depth, jint max_count, 833 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 834#ifdef ASSERT 835 uint32_t debug_bits = 0; 836#endif 837 assert((SafepointSynchronize::is_at_safepoint() || 838 is_thread_fully_suspended(java_thread, false, &debug_bits)), 839 "at safepoint or target thread is suspended"); 840 int count = 0; 841 if (java_thread->has_last_Java_frame()) { 842 RegisterMap reg_map(java_thread); 843 Thread* current_thread = Thread::current(); 844 ResourceMark rm(current_thread); 845 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 846 HandleMark hm(current_thread); 847 if (start_depth != 0) { 848 if (start_depth > 0) { 849 for (int j = 0; j < start_depth && jvf != NULL; j++) { 850 jvf = jvf->java_sender(); 851 } 852 if (jvf == NULL) { 853 // start_depth is deeper than the stack depth 854 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 855 } 856 } else { // start_depth < 0 857 // we are referencing the starting depth based on the oldest 858 // part of the stack. 859 // optimize to limit the number of times that java_sender() is called 860 javaVFrame *jvf_cursor = jvf; 861 javaVFrame *jvf_prev = NULL; 862 javaVFrame *jvf_prev_prev; 863 int j = 0; 864 while (jvf_cursor != NULL) { 865 jvf_prev_prev = jvf_prev; 866 jvf_prev = jvf_cursor; 867 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) { 868 jvf_cursor = jvf_cursor->java_sender(); 869 } 870 } 871 if (j == start_depth) { 872 // previous pointer is exactly where we want to start 873 jvf = jvf_prev; 874 } else { 875 // we need to back up further to get to the right place 876 if (jvf_prev_prev == NULL) { 877 // the -start_depth is greater than the stack depth 878 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 879 } 880 // j now is the number of frames on the stack starting with 881 // jvf_prev, we start from jvf_prev_prev and move older on 882 // the stack that many, the result is -start_depth frames 883 // remaining. 884 jvf = jvf_prev_prev; 885 for (; j < 0; j++) { 886 jvf = jvf->java_sender(); 887 } 888 } 889 } 890 } 891 for (; count < max_count && jvf != NULL; count++) { 892 frame_buffer[count].method = jvf->method()->jmethod_id(); 893 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 894 jvf = jvf->java_sender(); 895 } 896 } else { 897 if (start_depth != 0) { 898 // no frames and there is a starting depth 899 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 900 } 901 } 902 *count_ptr = count; 903 return JVMTI_ERROR_NONE; 904} 905 906jvmtiError 907JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) { 908 assert((state != NULL), 909 "JavaThread should create JvmtiThreadState before calling this method"); 910 *count_ptr = state->count_frames(); 911 return JVMTI_ERROR_NONE; 912} 913 914jvmtiError 915JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 916 jmethodID* method_ptr, jlocation* location_ptr) { 917#ifdef ASSERT 918 uint32_t debug_bits = 0; 919#endif 920 assert((SafepointSynchronize::is_at_safepoint() || 921 is_thread_fully_suspended(java_thread, false, &debug_bits)), 922 "at safepoint or target thread is suspended"); 923 Thread* current_thread = Thread::current(); 924 ResourceMark rm(current_thread); 925 926 vframe *vf = vframeFor(java_thread, depth); 927 if (vf == NULL) { 928 return JVMTI_ERROR_NO_MORE_FRAMES; 929 } 930 931 // vframeFor should return a java frame. If it doesn't 932 // it means we've got an internal error and we return the 933 // error in product mode. In debug mode we will instead 934 // attempt to cast the vframe to a javaVFrame and will 935 // cause an assertion/crash to allow further diagnosis. 936#ifdef PRODUCT 937 if (!vf->is_java_frame()) { 938 return JVMTI_ERROR_INTERNAL; 939 } 940#endif 941 942 HandleMark hm(current_thread); 943 javaVFrame *jvf = javaVFrame::cast(vf); 944 methodOop method = jvf->method(); 945 if (method->is_native()) { 946 *location_ptr = -1; 947 } else { 948 *location_ptr = jvf->bci(); 949 } 950 *method_ptr = method->jmethod_id(); 951 952 return JVMTI_ERROR_NONE; 953} 954 955 956jvmtiError 957JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 958 HandleMark hm; 959 Handle hobj; 960 961 bool at_safepoint = SafepointSynchronize::is_at_safepoint(); 962 963 // Check arguments 964 { 965 oop mirror = JNIHandles::resolve_external_guard(object); 966 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 967 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 968 969 hobj = Handle(mirror); 970 } 971 972 JavaThread *owning_thread = NULL; 973 ObjectMonitor *mon = NULL; 974 jvmtiMonitorUsage ret = { 975 NULL, 0, 0, NULL, 0, NULL 976 }; 977 978 uint32_t debug_bits = 0; 979 // first derive the object's owner and entry_count (if any) 980 { 981 // Revoke any biases before querying the mark word 982 if (SafepointSynchronize::is_at_safepoint()) { 983 BiasedLocking::revoke_at_safepoint(hobj); 984 } else { 985 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread); 986 } 987 988 address owner = NULL; 989 { 990 markOop mark = hobj()->mark(); 991 992 if (!mark->has_monitor()) { 993 // this object has a lightweight monitor 994 995 if (mark->has_locker()) { 996 owner = (address)mark->locker(); // save the address of the Lock word 997 } 998 // implied else: no owner 999 } else { 1000 // this object has a heavyweight monitor 1001 mon = mark->monitor(); 1002 1003 // The owner field of a heavyweight monitor may be NULL for no 1004 // owner, a JavaThread * or it may still be the address of the 1005 // Lock word in a JavaThread's stack. A monitor can be inflated 1006 // by a non-owning JavaThread, but only the owning JavaThread 1007 // can change the owner field from the Lock word to the 1008 // JavaThread * and it may not have done that yet. 1009 owner = (address)mon->owner(); 1010 } 1011 } 1012 1013 if (owner != NULL) { 1014 // This monitor is owned so we have to find the owning JavaThread. 1015 // Since owning_thread_from_monitor_owner() grabs a lock, GC can 1016 // move our object at this point. However, our owner value is safe 1017 // since it is either the Lock word on a stack or a JavaThread *. 1018 owning_thread = Threads::owning_thread_from_monitor_owner(owner, !at_safepoint); 1019 assert(owning_thread != NULL, "sanity check"); 1020 if (owning_thread != NULL) { // robustness 1021 // The monitor's owner either has to be the current thread, at safepoint 1022 // or it has to be suspended. Any of these conditions will prevent both 1023 // contending and waiting threads from modifying the state of 1024 // the monitor. 1025 if (!at_safepoint && !JvmtiEnv::is_thread_fully_suspended(owning_thread, true, &debug_bits)) { 1026 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1027 } 1028 HandleMark hm; 1029 Handle th(owning_thread->threadObj()); 1030 ret.owner = (jthread)jni_reference(calling_thread, th); 1031 } 1032 // implied else: no owner 1033 } 1034 1035 if (owning_thread != NULL) { // monitor is owned 1036 if ((address)owning_thread == owner) { 1037 // the owner field is the JavaThread * 1038 assert(mon != NULL, 1039 "must have heavyweight monitor with JavaThread * owner"); 1040 ret.entry_count = mon->recursions() + 1; 1041 } else { 1042 // The owner field is the Lock word on the JavaThread's stack 1043 // so the recursions field is not valid. We have to count the 1044 // number of recursive monitor entries the hard way. We pass 1045 // a handle to survive any GCs along the way. 1046 ResourceMark rm; 1047 ret.entry_count = count_locked_objects(owning_thread, hobj); 1048 } 1049 } 1050 // implied else: entry_count == 0 1051 } 1052 1053 int nWant,nWait; 1054 if (mon != NULL) { 1055 // this object has a heavyweight monitor 1056 nWant = mon->contentions(); // # of threads contending for monitor 1057 nWait = mon->waiters(); // # of threads in Object.wait() 1058 ret.waiter_count = nWant + nWait; 1059 ret.notify_waiter_count = nWait; 1060 } else { 1061 // this object has a lightweight monitor 1062 ret.waiter_count = 0; 1063 ret.notify_waiter_count = 0; 1064 } 1065 1066 // Allocate memory for heavyweight and lightweight monitor. 1067 jvmtiError err; 1068 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1069 if (err != JVMTI_ERROR_NONE) { 1070 return err; 1071 } 1072 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1073 (unsigned char**)&ret.notify_waiters); 1074 if (err != JVMTI_ERROR_NONE) { 1075 deallocate((unsigned char*)ret.waiters); 1076 return err; 1077 } 1078 1079 // now derive the rest of the fields 1080 if (mon != NULL) { 1081 // this object has a heavyweight monitor 1082 1083 // Number of waiters may actually be less than the waiter count. 1084 // So NULL out memory so that unused memory will be NULL. 1085 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1086 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1087 1088 if (ret.waiter_count > 0) { 1089 // we have contending and/or waiting threads 1090 HandleMark hm; 1091 if (nWant > 0) { 1092 // we have contending threads 1093 ResourceMark rm; 1094 // get_pending_threads returns only java thread so we do not need to 1095 // check for non java threads. 1096 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads( 1097 nWant, (address)mon, !at_safepoint); 1098 if (wantList->length() < nWant) { 1099 // robustness: the pending list has gotten smaller 1100 nWant = wantList->length(); 1101 } 1102 for (int i = 0; i < nWant; i++) { 1103 JavaThread *pending_thread = wantList->at(i); 1104 // If the monitor has no owner, then a non-suspended contending 1105 // thread could potentially change the state of the monitor by 1106 // entering it. The JVM/TI spec doesn't allow this. 1107 if (owning_thread == NULL && !at_safepoint & 1108 !JvmtiEnv::is_thread_fully_suspended(pending_thread, true, &debug_bits)) { 1109 if (ret.owner != NULL) { 1110 destroy_jni_reference(calling_thread, ret.owner); 1111 } 1112 for (int j = 0; j < i; j++) { 1113 destroy_jni_reference(calling_thread, ret.waiters[j]); 1114 } 1115 deallocate((unsigned char*)ret.waiters); 1116 deallocate((unsigned char*)ret.notify_waiters); 1117 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1118 } 1119 Handle th(pending_thread->threadObj()); 1120 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1121 } 1122 } 1123 if (nWait > 0) { 1124 // we have threads in Object.wait() 1125 int offset = nWant; // add after any contending threads 1126 ObjectWaiter *waiter = mon->first_waiter(); 1127 for (int i = 0, j = 0; i < nWait; i++) { 1128 if (waiter == NULL) { 1129 // robustness: the waiting list has gotten smaller 1130 nWait = j; 1131 break; 1132 } 1133 Thread *t = mon->thread_of_waiter(waiter); 1134 if (t != NULL && t->is_Java_thread()) { 1135 JavaThread *wjava_thread = (JavaThread *)t; 1136 // If the thread was found on the ObjectWaiter list, then 1137 // it has not been notified. This thread can't change the 1138 // state of the monitor so it doesn't need to be suspended. 1139 Handle th(wjava_thread->threadObj()); 1140 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th); 1141 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th); 1142 } 1143 waiter = mon->next_waiter(waiter); 1144 } 1145 } 1146 } 1147 1148 // Adjust count. nWant and nWait count values may be less than original. 1149 ret.waiter_count = nWant + nWait; 1150 ret.notify_waiter_count = nWait; 1151 } else { 1152 // this object has a lightweight monitor and we have nothing more 1153 // to do here because the defaults are just fine. 1154 } 1155 1156 // we don't update return parameter unless everything worked 1157 *info_ptr = ret; 1158 1159 return JVMTI_ERROR_NONE; 1160} 1161 1162ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1163 _env = env; 1164 _allocations = new (ResourceObj::C_HEAP) GrowableArray<unsigned char*>(20, true); 1165 _failed = false; 1166} 1167ResourceTracker::~ResourceTracker() { 1168 if (_failed) { 1169 for (int i=0; i<_allocations->length(); i++) { 1170 _env->deallocate(_allocations->at(i)); 1171 } 1172 } 1173 delete _allocations; 1174} 1175 1176jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1177 unsigned char *ptr; 1178 jvmtiError err = _env->allocate(size, &ptr); 1179 if (err == JVMTI_ERROR_NONE) { 1180 _allocations->append(ptr); 1181 *mem_ptr = ptr; 1182 } else { 1183 *mem_ptr = NULL; 1184 _failed = true; 1185 } 1186 return err; 1187 } 1188 1189unsigned char* ResourceTracker::allocate(jlong size) { 1190 unsigned char* ptr; 1191 allocate(size, &ptr); 1192 return ptr; 1193} 1194 1195char* ResourceTracker::strdup(const char* str) { 1196 char *dup_str = (char*)allocate(strlen(str)+1); 1197 if (dup_str != NULL) { 1198 strcpy(dup_str, str); 1199 } 1200 return dup_str; 1201} 1202 1203struct StackInfoNode { 1204 struct StackInfoNode *next; 1205 jvmtiStackInfo info; 1206}; 1207 1208// Create a jvmtiStackInfo inside a linked list node and create a 1209// buffer for the frame information, both allocated as resource objects. 1210// Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1211// Note that either or both of thr and thread_oop 1212// may be null if the thread is new or has exited. 1213void 1214VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1215 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1216 1217 jint state = 0; 1218 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1219 jvmtiStackInfo *infop = &(node->info); 1220 node->next = head(); 1221 set_head(node); 1222 infop->frame_count = 0; 1223 infop->thread = jt; 1224 1225 if (thread_oop != NULL) { 1226 // get most state bits 1227 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 1228 } 1229 1230 if (thr != NULL) { // add more state bits if there is a JavaThead to query 1231 // same as is_being_ext_suspended() but without locking 1232 if (thr->is_ext_suspended() || thr->is_external_suspend()) { 1233 state |= JVMTI_THREAD_STATE_SUSPENDED; 1234 } 1235 JavaThreadState jts = thr->thread_state(); 1236 if (jts == _thread_in_native) { 1237 state |= JVMTI_THREAD_STATE_IN_NATIVE; 1238 } 1239 OSThread* osThread = thr->osthread(); 1240 if (osThread != NULL && osThread->interrupted()) { 1241 state |= JVMTI_THREAD_STATE_INTERRUPTED; 1242 } 1243 } 1244 infop->state = state; 1245 1246 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1247 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1248 env()->get_stack_trace(thr, 0, max_frame_count(), 1249 infop->frame_buffer, &(infop->frame_count)); 1250 } else { 1251 infop->frame_buffer = NULL; 1252 infop->frame_count = 0; 1253 } 1254 _frame_count_total += infop->frame_count; 1255} 1256 1257// Based on the stack information in the linked list, allocate memory 1258// block to return and fill it from the info in the linked list. 1259void 1260VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) { 1261 // do I need to worry about alignment issues? 1262 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1263 + _frame_count_total * sizeof(jvmtiFrameInfo); 1264 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1265 1266 // pointers to move through the newly allocated space as it is filled in 1267 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1268 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1269 1270 // copy information in resource area into allocated buffer 1271 // insert stack info backwards since linked list is backwards 1272 // insert frame info forwards 1273 // walk the StackInfoNodes 1274 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) { 1275 jint frame_count = sin->info.frame_count; 1276 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1277 --si; 1278 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1279 if (frames_size == 0) { 1280 si->frame_buffer = NULL; 1281 } else { 1282 memcpy(fi, sin->info.frame_buffer, frames_size); 1283 si->frame_buffer = fi; // point to the new allocated copy of the frames 1284 fi += frame_count; 1285 } 1286 } 1287 assert(si == _stack_info, "the last copied stack info must be the first record"); 1288 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1289 "the last copied frame info must be the last record"); 1290} 1291 1292 1293void 1294VM_GetThreadListStackTraces::doit() { 1295 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1296 1297 ResourceMark rm; 1298 for (int i = 0; i < _thread_count; ++i) { 1299 jthread jt = _thread_list[i]; 1300 oop thread_oop = JNIHandles::resolve_external_guard(jt); 1301 if (thread_oop == NULL || !thread_oop->is_a(SystemDictionary::Thread_klass())) { 1302 set_result(JVMTI_ERROR_INVALID_THREAD); 1303 return; 1304 } 1305 fill_frames(jt, java_lang_Thread::thread(thread_oop), thread_oop); 1306 } 1307 allocate_and_fill_stacks(_thread_count); 1308} 1309 1310void 1311VM_GetAllStackTraces::doit() { 1312 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1313 1314 ResourceMark rm; 1315 _final_thread_count = 0; 1316 for (JavaThread *jt = Threads::first(); jt != NULL; jt = jt->next()) { 1317 oop thread_oop = jt->threadObj(); 1318 if (thread_oop != NULL && 1319 !jt->is_exiting() && 1320 java_lang_Thread::is_alive(thread_oop) && 1321 !jt->is_hidden_from_external_view()) { 1322 ++_final_thread_count; 1323 // Handle block of the calling thread is used to create local refs. 1324 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 1325 jt, thread_oop); 1326 } 1327 } 1328 allocate_and_fill_stacks(_final_thread_count); 1329} 1330 1331// Verifies that the top frame is a java frame in an expected state. 1332// Deoptimizes frame if needed. 1333// Checks that the frame method signature matches the return type (tos). 1334// HandleMark must be defined in the caller only. 1335// It is to keep a ret_ob_h handle alive after return to the caller. 1336jvmtiError 1337JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread, 1338 jvalue value, TosState tos, Handle* ret_ob_h) { 1339 ResourceMark rm(current_thread); 1340 1341 vframe *vf = vframeFor(java_thread, 0); 1342 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES); 1343 1344 javaVFrame *jvf = (javaVFrame*) vf; 1345 if (!vf->is_java_frame() || jvf->method()->is_native()) { 1346 return JVMTI_ERROR_OPAQUE_FRAME; 1347 } 1348 1349 // If the frame is a compiled one, need to deoptimize it. 1350 if (vf->is_compiled_frame()) { 1351 if (!vf->fr().can_be_deoptimized()) { 1352 return JVMTI_ERROR_OPAQUE_FRAME; 1353 } 1354 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 1355 } 1356 1357 // Get information about method return type 1358 Symbol* signature = jvf->method()->signature(); 1359 1360 ResultTypeFinder rtf(signature); 1361 TosState fr_tos = as_TosState(rtf.type()); 1362 if (fr_tos != tos) { 1363 if (tos != itos || (fr_tos != btos && fr_tos != ctos && fr_tos != stos)) { 1364 return JVMTI_ERROR_TYPE_MISMATCH; 1365 } 1366 } 1367 1368 // Check that the jobject class matches the return type signature. 1369 jobject jobj = value.l; 1370 if (tos == atos && jobj != NULL) { // NULL reference is allowed 1371 Handle ob_h = Handle(current_thread, JNIHandles::resolve_external_guard(jobj)); 1372 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 1373 KlassHandle ob_kh = KlassHandle(current_thread, ob_h()->klass()); 1374 NULL_CHECK(ob_kh, JVMTI_ERROR_INVALID_OBJECT); 1375 1376 // Method return type signature. 1377 char* ty_sign = 1 + strchr(signature->as_C_string(), ')'); 1378 1379 if (!VM_GetOrSetLocal::is_assignable(ty_sign, Klass::cast(ob_kh()), current_thread)) { 1380 return JVMTI_ERROR_TYPE_MISMATCH; 1381 } 1382 *ret_ob_h = ob_h; 1383 } 1384 return JVMTI_ERROR_NONE; 1385} /* end check_top_frame */ 1386 1387 1388// ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 1389// Main difference is on the last stage in the interpreter. 1390// The PopFrame stops method execution to continue execution 1391// from the same method call instruction. 1392// The ForceEarlyReturn forces return from method so the execution 1393// continues at the bytecode following the method call. 1394 1395// Threads_lock NOT held, java_thread not protected by lock 1396// java_thread - pre-checked 1397 1398jvmtiError 1399JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) { 1400 JavaThread* current_thread = JavaThread::current(); 1401 HandleMark hm(current_thread); 1402 uint32_t debug_bits = 0; 1403 1404 // retrieve or create the state 1405 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 1406 if (state == NULL) { 1407 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1408 } 1409 1410 // Check if java_thread is fully suspended 1411 if (!is_thread_fully_suspended(java_thread, 1412 true /* wait for suspend completion */, 1413 &debug_bits)) { 1414 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1415 } 1416 1417 // Check to see if a ForceEarlyReturn was already in progress 1418 if (state->is_earlyret_pending()) { 1419 // Probably possible for JVMTI clients to trigger this, but the 1420 // JPDA backend shouldn't allow this to happen 1421 return JVMTI_ERROR_INTERNAL; 1422 } 1423 { 1424 // The same as for PopFrame. Workaround bug: 1425 // 4812902: popFrame hangs if the method is waiting at a synchronize 1426 // Catch this condition and return an error to avoid hanging. 1427 // Now JVMTI spec allows an implementation to bail out with an opaque 1428 // frame error. 1429 OSThread* osThread = java_thread->osthread(); 1430 if (osThread->get_state() == MONITOR_WAIT) { 1431 return JVMTI_ERROR_OPAQUE_FRAME; 1432 } 1433 } 1434 Handle ret_ob_h = Handle(); 1435 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h); 1436 if (err != JVMTI_ERROR_NONE) { 1437 return err; 1438 } 1439 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL, 1440 "return object oop must not be NULL if jobject is not NULL"); 1441 1442 // Update the thread state to reflect that the top frame must be 1443 // forced to return. 1444 // The current frame will be returned later when the suspended 1445 // thread is resumed and right before returning from VM to Java. 1446 // (see call_VM_base() in assembler_<cpu>.cpp). 1447 1448 state->set_earlyret_pending(); 1449 state->set_earlyret_oop(ret_ob_h()); 1450 state->set_earlyret_value(value, tos); 1451 1452 // Set pending step flag for this early return. 1453 // It is cleared when next step event is posted. 1454 state->set_pending_step_for_earlyret(); 1455 1456 return JVMTI_ERROR_NONE; 1457} /* end force_early_return */ 1458 1459void 1460JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 1461 if ( _error != JVMTI_ERROR_NONE) { 1462 // Error occurred in previous iteration so no need to add 1463 // to the list. 1464 return; 1465 } 1466 if (mon->owner() == _java_thread ) { 1467 // Filter out on stack monitors collected during stack walk. 1468 oop obj = (oop)mon->object(); 1469 bool found = false; 1470 for (int j = 0; j < _owned_monitors_list->length(); j++) { 1471 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 1472 oop check = JNIHandles::resolve(jobj); 1473 if (check == obj) { 1474 // On stack monitor already collected during the stack walk. 1475 found = true; 1476 break; 1477 } 1478 } 1479 if (found == false) { 1480 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 1481 jvmtiError err; 1482 jvmtiMonitorStackDepthInfo *jmsdi; 1483 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1484 if (err != JVMTI_ERROR_NONE) { 1485 _error = err; 1486 return; 1487 } 1488 Handle hobj(obj); 1489 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 1490 // stack depth is unknown for this monitor. 1491 jmsdi->stack_depth = -1; 1492 _owned_monitors_list->append(jmsdi); 1493 } 1494 } 1495} 1496 1497#endif // !JVMTI_KERNEL 1498