src/share/vm/prims/jvmtiEnvBase.cpp

Tue, 06 Jan 2009 07:05:05 -0800

author
jmasa
date
Tue, 06 Jan 2009 07:05:05 -0800
changeset 952
e9be0e04635a
parent 806
dbec32712472
child 905
ad8c8ca4ab0f
permissions
-rw-r--r--

6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
Summary: Added safe_object_iterate() for use by JMapPerm.
Reviewed-by: tonyp

     1 /*
     2  * Copyright 2003-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    24 # include "incls/_precompiled.incl"
    25 # include "incls/_jvmtiEnvBase.cpp.incl"
    28 ///////////////////////////////////////////////////////////////
    29 //
    30 // JvmtiEnvBase
    31 //
    33 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
    35 bool JvmtiEnvBase::_globally_initialized = false;
    36 volatile bool JvmtiEnvBase::_needs_clean_up = false;
    38 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
    40 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
    42 extern jvmtiInterface_1_ jvmti_Interface;
    43 extern jvmtiInterface_1_ jvmtiTrace_Interface;
    46 // perform initializations that must occur before any JVMTI environments
    47 // are released but which should only be initialized once (no matter
    48 // how many environments are created).
    49 void
    50 JvmtiEnvBase::globally_initialize() {
    51   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
    52   assert(_globally_initialized == false, "bad call");
    54   JvmtiManageCapabilities::initialize();
    56 #ifndef JVMTI_KERNEL
    57   // register extension functions and events
    58   JvmtiExtensions::register_extensions();
    59 #endif // !JVMTI_KERNEL
    61 #ifdef JVMTI_TRACE
    62   JvmtiTrace::initialize();
    63 #endif
    65   _globally_initialized = true;
    66 }
    69 void
    70 JvmtiEnvBase::initialize() {
    71   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
    73   // Add this environment to the end of the environment list (order is important)
    74   {
    75     // This block of code must not contain any safepoints, as list deallocation
    76     // (which occurs at a safepoint) cannot occur simultaneously with this list
    77     // addition.  Note: No_Safepoint_Verifier cannot, currently, be used before
    78     // threads exist.
    79     JvmtiEnvIterator it;
    80     JvmtiEnvBase *previous_env = NULL;
    81     for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
    82       previous_env = env;
    83     }
    84     if (previous_env == NULL) {
    85       _head_environment = this;
    86     } else {
    87       previous_env->set_next_environment(this);
    88     }
    89   }
    91   if (_globally_initialized == false) {
    92     globally_initialize();
    93   }
    94 }
    97 JvmtiEnvBase::JvmtiEnvBase() : _env_event_enable() {
    98   _env_local_storage = NULL;
    99   _tag_map = NULL;
   100   _native_method_prefix_count = 0;
   101   _native_method_prefixes = NULL;
   102   _next = NULL;
   103   _class_file_load_hook_ever_enabled = false;
   105   // Moot since ClassFileLoadHook not yet enabled.
   106   // But "true" will give a more predictable ClassFileLoadHook behavior
   107   // for environment creation during ClassFileLoadHook.
   108   _is_retransformable = true;
   110   // all callbacks initially NULL
   111   memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
   113   // all capabilities initially off
   114   memset(&_current_capabilities, 0, sizeof(_current_capabilities));
   116   // all prohibited capabilities initially off
   117   memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
   119   _magic = JVMTI_MAGIC;
   121   JvmtiEventController::env_initialize((JvmtiEnv*)this);
   123 #ifdef JVMTI_TRACE
   124   _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
   125 #else
   126   _jvmti_external.functions = &jvmti_Interface;
   127 #endif
   128 }
   131 void
   132 JvmtiEnvBase::dispose() {
   134 #ifdef JVMTI_TRACE
   135   JvmtiTrace::shutdown();
   136 #endif
   138   // Dispose of event info and let the event controller call us back
   139   // in a locked state (env_dispose, below)
   140   JvmtiEventController::env_dispose(this);
   141 }
   143 void
   144 JvmtiEnvBase::env_dispose() {
   145   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   147   // We have been entered with all events disabled on this environment.
   148   // A race to re-enable events (by setting callbacks) is prevented by
   149   // checking for a valid environment when setting callbacks (while
   150   // holding the JvmtiThreadState_lock).
   152   // Mark as invalid.
   153   _magic = DISPOSED_MAGIC;
   155   // Relinquish all capabilities.
   156   jvmtiCapabilities *caps = get_capabilities();
   157   JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
   159   // Same situation as with events (see above)
   160   set_native_method_prefixes(0, NULL);
   162 #ifndef JVMTI_KERNEL
   163   JvmtiTagMap* tag_map_to_deallocate = _tag_map;
   164   set_tag_map(NULL);
   165   // A tag map can be big, deallocate it now
   166   if (tag_map_to_deallocate != NULL) {
   167     delete tag_map_to_deallocate;
   168   }
   169 #endif // !JVMTI_KERNEL
   171   _needs_clean_up = true;
   172 }
   175 JvmtiEnvBase::~JvmtiEnvBase() {
   176   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   178   // There is a small window of time during which the tag map of a
   179   // disposed environment could have been reallocated.
   180   // Make sure it is gone.
   181 #ifndef JVMTI_KERNEL
   182   JvmtiTagMap* tag_map_to_deallocate = _tag_map;
   183   set_tag_map(NULL);
   184   // A tag map can be big, deallocate it now
   185   if (tag_map_to_deallocate != NULL) {
   186     delete tag_map_to_deallocate;
   187   }
   188 #endif // !JVMTI_KERNEL
   190   _magic = BAD_MAGIC;
   191 }
   194 void
   195 JvmtiEnvBase::periodic_clean_up() {
   196   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   198   // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
   199   // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
   200   JvmtiThreadState::periodic_clean_up();
   202   // Unlink all invalid environments from the list of environments
   203   // and deallocate them
   204   JvmtiEnvIterator it;
   205   JvmtiEnvBase* previous_env = NULL;
   206   JvmtiEnvBase* env = it.first();
   207   while (env != NULL) {
   208     if (env->is_valid()) {
   209       previous_env = env;
   210       env = it.next(env);
   211     } else {
   212       // This one isn't valid, remove it from the list and deallocate it
   213       JvmtiEnvBase* defunct_env = env;
   214       env = it.next(env);
   215       if (previous_env == NULL) {
   216         _head_environment = env;
   217       } else {
   218         previous_env->set_next_environment(env);
   219       }
   220       delete defunct_env;
   221     }
   222   }
   224 }
   227 void
   228 JvmtiEnvBase::check_for_periodic_clean_up() {
   229   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   231   class ThreadInsideIterationClosure: public ThreadClosure {
   232    private:
   233     bool _inside;
   234    public:
   235     ThreadInsideIterationClosure() : _inside(false) {};
   237     void do_thread(Thread* thread) {
   238       _inside |= thread->is_inside_jvmti_env_iteration();
   239     }
   241     bool is_inside_jvmti_env_iteration() {
   242       return _inside;
   243     }
   244   };
   246   if (_needs_clean_up) {
   247     // Check if we are currently iterating environment,
   248     // deallocation should not occur if we are
   249     ThreadInsideIterationClosure tiic;
   250     Threads::threads_do(&tiic);
   251     if (!tiic.is_inside_jvmti_env_iteration() &&
   252              !is_inside_dying_thread_env_iteration()) {
   253       _needs_clean_up = false;
   254       JvmtiEnvBase::periodic_clean_up();
   255     }
   256   }
   257 }
   260 void
   261 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
   262   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
   263          "sanity check");
   265   if (!_class_file_load_hook_ever_enabled) {
   266     _class_file_load_hook_ever_enabled = true;
   268     if (get_capabilities()->can_retransform_classes) {
   269       _is_retransformable = true;
   270     } else {
   271       _is_retransformable = false;
   273       // cannot add retransform capability after ClassFileLoadHook has been enabled
   274       get_prohibited_capabilities()->can_retransform_classes = 1;
   275     }
   276   }
   277 }
   280 void
   281 JvmtiEnvBase::record_class_file_load_hook_enabled() {
   282   if (!_class_file_load_hook_ever_enabled) {
   283     if (Threads::number_of_threads() == 0) {
   284       record_first_time_class_file_load_hook_enabled();
   285     } else {
   286       MutexLocker mu(JvmtiThreadState_lock);
   287       record_first_time_class_file_load_hook_enabled();
   288     }
   289   }
   290 }
   293 jvmtiError
   294 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
   295   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
   296          "sanity check");
   298   int old_prefix_count = get_native_method_prefix_count();
   299   char **old_prefixes = get_native_method_prefixes();
   301   // allocate and install the new prefixex
   302   if (prefix_count == 0 || !is_valid()) {
   303     _native_method_prefix_count = 0;
   304     _native_method_prefixes = NULL;
   305   } else {
   306     // there are prefixes, allocate an array to hold them, and fill it
   307     char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*));
   308     if (new_prefixes == NULL) {
   309       return JVMTI_ERROR_OUT_OF_MEMORY;
   310     }
   311     for (int i = 0; i < prefix_count; i++) {
   312       char* prefix = prefixes[i];
   313       if (prefix == NULL) {
   314         for (int j = 0; j < (i-1); j++) {
   315           os::free(new_prefixes[j]);
   316         }
   317         os::free(new_prefixes);
   318         return JVMTI_ERROR_NULL_POINTER;
   319       }
   320       prefix = os::strdup(prefixes[i]);
   321       if (prefix == NULL) {
   322         for (int j = 0; j < (i-1); j++) {
   323           os::free(new_prefixes[j]);
   324         }
   325         os::free(new_prefixes);
   326         return JVMTI_ERROR_OUT_OF_MEMORY;
   327       }
   328       new_prefixes[i] = prefix;
   329     }
   330     _native_method_prefix_count = prefix_count;
   331     _native_method_prefixes = new_prefixes;
   332   }
   334   // now that we know the new prefixes have been successfully installed we can
   335   // safely remove the old ones
   336   if (old_prefix_count != 0) {
   337     for (int i = 0; i < old_prefix_count; i++) {
   338       os::free(old_prefixes[i]);
   339     }
   340     os::free(old_prefixes);
   341   }
   343   return JVMTI_ERROR_NONE;
   344 }
   347 // Collect all the prefixes which have been set in any JVM TI environments
   348 // by the SetNativeMethodPrefix(es) functions.  Be sure to maintain the
   349 // order of environments and the order of prefixes within each environment.
   350 // Return in a resource allocated array.
   351 char**
   352 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
   353   assert(Threads::number_of_threads() == 0 ||
   354          SafepointSynchronize::is_at_safepoint() ||
   355          JvmtiThreadState_lock->is_locked(),
   356          "sanity check");
   358   int total_count = 0;
   359   GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
   361   JvmtiEnvIterator it;
   362   for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
   363     int prefix_count = env->get_native_method_prefix_count();
   364     char** prefixes = env->get_native_method_prefixes();
   365     for (int j = 0; j < prefix_count; j++) {
   366       // retrieve a prefix and so that it is safe against asynchronous changes
   367       // copy it into the resource area
   368       char* prefix = prefixes[j];
   369       char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
   370       strcpy(prefix_copy, prefix);
   371       prefix_array->at_put_grow(total_count++, prefix_copy);
   372     }
   373   }
   375   char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
   376   char** p = all_prefixes;
   377   for (int i = 0; i < total_count; ++i) {
   378     *p++ = prefix_array->at(i);
   379   }
   380   *count_ptr = total_count;
   381   return all_prefixes;
   382 }
   384 void
   385 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
   386                                                jint size_of_callbacks) {
   387   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   389   size_t byte_cnt = sizeof(jvmtiEventCallbacks);
   391   // clear in either case to be sure we got any gap between sizes
   392   memset(&_event_callbacks, 0, byte_cnt);
   394   // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
   395   // are re-enabled by a call to set event callbacks where the DisposeEnvironment
   396   // occurs after the boiler-plate environment check and before the lock is acquired.
   397   if (callbacks != NULL && is_valid()) {
   398     if (size_of_callbacks < (jint)byte_cnt) {
   399       byte_cnt = size_of_callbacks;
   400     }
   401     memcpy(&_event_callbacks, callbacks, byte_cnt);
   402   }
   403 }
   405 // Called from JVMTI entry points which perform stack walking. If the
   406 // associated JavaThread is the current thread, then wait_for_suspend
   407 // is not used. Otherwise, it determines if we should wait for the
   408 // "other" thread to complete external suspension. (NOTE: in future
   409 // releases the suspension mechanism should be reimplemented so this
   410 // is not necessary.)
   411 //
   412 bool
   413 JvmtiEnvBase::is_thread_fully_suspended(JavaThread* thr, bool wait_for_suspend, uint32_t *bits) {
   414   // "other" threads require special handling
   415   if (thr != JavaThread::current()) {
   416     if (wait_for_suspend) {
   417       // We are allowed to wait for the external suspend to complete
   418       // so give the other thread a chance to get suspended.
   419       if (!thr->wait_for_ext_suspend_completion(SuspendRetryCount,
   420           SuspendRetryDelay, bits)) {
   421         // didn't make it so let the caller know
   422         return false;
   423       }
   424     }
   425     // We aren't allowed to wait for the external suspend to complete
   426     // so if the other thread isn't externally suspended we need to
   427     // let the caller know.
   428     else if (!thr->is_ext_suspend_completed_with_lock(bits)) {
   429       return false;
   430     }
   431   }
   433   return true;
   434 }
   437 // In the fullness of time, all users of the method should instead
   438 // directly use allocate, besides being cleaner and faster, this will
   439 // mean much better out of memory handling
   440 unsigned char *
   441 JvmtiEnvBase::jvmtiMalloc(jlong size) {
   442   unsigned char* mem;
   443   jvmtiError result = allocate(size, &mem);
   444   assert(result == JVMTI_ERROR_NONE, "Allocate failed");
   445   return mem;
   446 }
   449 //
   450 // Threads
   451 //
   453 jobject *
   454 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
   455   if (length == 0) {
   456     return NULL;
   457   }
   459   jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
   460   NULL_CHECK(objArray, NULL);
   462   for (int i=0; i<length; i++) {
   463     objArray[i] = jni_reference(handles[i]);
   464   }
   465   return objArray;
   466 }
   468 jthread *
   469 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
   470   return (jthread *) new_jobjectArray(length,handles);
   471 }
   473 jthreadGroup *
   474 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
   475   return (jthreadGroup *) new_jobjectArray(length,handles);
   476 }
   479 JavaThread *
   480 JvmtiEnvBase::get_JavaThread(jthread jni_thread) {
   481   oop t = JNIHandles::resolve_external_guard(jni_thread);
   482   if (t == NULL || !t->is_a(SystemDictionary::thread_klass())) {
   483     return NULL;
   484   }
   485   // The following returns NULL if the thread has not yet run or is in
   486   // process of exiting
   487   return java_lang_Thread::thread(t);
   488 }
   491 // update the access_flags for the field in the klass
   492 void
   493 JvmtiEnvBase::update_klass_field_access_flag(fieldDescriptor *fd) {
   494   instanceKlass* ik = instanceKlass::cast(fd->field_holder());
   495   typeArrayOop fields = ik->fields();
   496   fields->ushort_at_put(fd->index(), (jushort)fd->access_flags().as_short());
   497 }
   500 // return the vframe on the specified thread and depth, NULL if no such frame
   501 vframe*
   502 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
   503   if (!java_thread->has_last_Java_frame()) {
   504     return NULL;
   505   }
   506   RegisterMap reg_map(java_thread);
   507   vframe *vf = java_thread->last_java_vframe(&reg_map);
   508   int d = 0;
   509   while ((vf != NULL) && (d < depth)) {
   510     vf = vf->java_sender();
   511     d++;
   512   }
   513   return vf;
   514 }
   517 //
   518 // utilities: JNI objects
   519 //
   522 jclass
   523 JvmtiEnvBase::get_jni_class_non_null(klassOop k) {
   524   assert(k != NULL, "k != NULL");
   525   return (jclass)jni_reference(Klass::cast(k)->java_mirror());
   526 }
   528 #ifndef JVMTI_KERNEL
   530 //
   531 // Field Information
   532 //
   534 bool
   535 JvmtiEnvBase::get_field_descriptor(klassOop k, jfieldID field, fieldDescriptor* fd) {
   536   if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
   537     return false;
   538   }
   539   bool found = false;
   540   if (jfieldIDWorkaround::is_static_jfieldID(field)) {
   541     JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
   542     int offset = id->offset();
   543     klassOop holder = id->holder();
   544     found = instanceKlass::cast(holder)->find_local_field_from_offset(offset, true, fd);
   545   } else {
   546     // Non-static field. The fieldID is really the offset of the field within the object.
   547     int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
   548     found = instanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
   549   }
   550   return found;
   551 }
   553 //
   554 // Object Monitor Information
   555 //
   557 //
   558 // Count the number of objects for a lightweight monitor. The hobj
   559 // parameter is object that owns the monitor so this routine will
   560 // count the number of times the same object was locked by frames
   561 // in java_thread.
   562 //
   563 jint
   564 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
   565   jint ret = 0;
   566   if (!java_thread->has_last_Java_frame()) {
   567     return ret;  // no Java frames so no monitors
   568   }
   570   ResourceMark rm;
   571   HandleMark   hm;
   572   RegisterMap  reg_map(java_thread);
   574   for(javaVFrame *jvf=java_thread->last_java_vframe(&reg_map); jvf != NULL;
   575                                                  jvf = jvf->java_sender()) {
   576     GrowableArray<MonitorInfo*>* mons = jvf->monitors();
   577     if (!mons->is_empty()) {
   578       for (int i = 0; i < mons->length(); i++) {
   579         MonitorInfo *mi = mons->at(i);
   581         // see if owner of the monitor is our object
   582         if (mi->owner() != NULL && mi->owner() == hobj()) {
   583           ret++;
   584         }
   585       }
   586     }
   587   }
   588   return ret;
   589 }
   593 jvmtiError
   594 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
   595 #ifdef ASSERT
   596   uint32_t debug_bits = 0;
   597 #endif
   598   assert((SafepointSynchronize::is_at_safepoint() ||
   599           is_thread_fully_suspended(java_thread, false, &debug_bits)),
   600          "at safepoint or target thread is suspended");
   601   oop obj = NULL;
   602   ObjectMonitor *mon = java_thread->current_waiting_monitor();
   603   if (mon == NULL) {
   604     // thread is not doing an Object.wait() call
   605     mon = java_thread->current_pending_monitor();
   606     if (mon != NULL) {
   607       // The thread is trying to enter() or raw_enter() an ObjectMonitor.
   608       obj = (oop)mon->object();
   609       // If obj == NULL, then ObjectMonitor is raw which doesn't count
   610       // as contended for this API
   611     }
   612     // implied else: no contended ObjectMonitor
   613   } else {
   614     // thread is doing an Object.wait() call
   615     obj = (oop)mon->object();
   616     assert(obj != NULL, "Object.wait() should have an object");
   617   }
   619   if (obj == NULL) {
   620     *monitor_ptr = NULL;
   621   } else {
   622     HandleMark hm;
   623     Handle     hobj(obj);
   624     *monitor_ptr = jni_reference(calling_thread, hobj);
   625   }
   626   return JVMTI_ERROR_NONE;
   627 }
   630 jvmtiError
   631 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
   632                                  GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
   633   jvmtiError err = JVMTI_ERROR_NONE;
   634 #ifdef ASSERT
   635   uint32_t debug_bits = 0;
   636 #endif
   637   assert((SafepointSynchronize::is_at_safepoint() ||
   638           is_thread_fully_suspended(java_thread, false, &debug_bits)),
   639          "at safepoint or target thread is suspended");
   641   if (java_thread->has_last_Java_frame()) {
   642     ResourceMark rm;
   643     HandleMark   hm;
   644     RegisterMap  reg_map(java_thread);
   646     int depth = 0;
   647     for (javaVFrame *jvf = java_thread->last_java_vframe(&reg_map); jvf != NULL;
   648          jvf = jvf->java_sender()) {
   649       if (depth++ < MaxJavaStackTraceDepth) {  // check for stack too deep
   650         // add locked objects for this frame into list
   651         err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
   652         if (err != JVMTI_ERROR_NONE) {
   653           return err;
   654         }
   655       }
   656     }
   657   }
   659   // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
   660   JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
   661   ObjectSynchronizer::monitors_iterate(&jmc);
   662   err = jmc.error();
   664   return err;
   665 }
   667 // Save JNI local handles for any objects that this frame owns.
   668 jvmtiError
   669 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
   670                                  javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) {
   671   jvmtiError err = JVMTI_ERROR_NONE;
   672   ResourceMark rm;
   674   GrowableArray<MonitorInfo*>* mons = jvf->monitors();
   675   if (mons->is_empty()) {
   676     return err;  // this javaVFrame holds no monitors
   677   }
   679   HandleMark hm;
   680   oop wait_obj = NULL;
   681   {
   682     // save object of current wait() call (if any) for later comparison
   683     ObjectMonitor *mon = java_thread->current_waiting_monitor();
   684     if (mon != NULL) {
   685       wait_obj = (oop)mon->object();
   686     }
   687   }
   688   oop pending_obj = NULL;
   689   {
   690     // save object of current enter() call (if any) for later comparison
   691     ObjectMonitor *mon = java_thread->current_pending_monitor();
   692     if (mon != NULL) {
   693       pending_obj = (oop)mon->object();
   694     }
   695   }
   697   for (int i = 0; i < mons->length(); i++) {
   698     MonitorInfo *mi = mons->at(i);
   700     oop obj = mi->owner();
   701     if (obj == NULL) {
   702       // this monitor doesn't have an owning object so skip it
   703       continue;
   704     }
   706     if (wait_obj == obj) {
   707       // the thread is waiting on this monitor so it isn't really owned
   708       continue;
   709     }
   711     if (pending_obj == obj) {
   712       // the thread is pending on this monitor so it isn't really owned
   713       continue;
   714     }
   716     if (owned_monitors_list->length() > 0) {
   717       // Our list has at least one object on it so we have to check
   718       // for recursive object locking
   719       bool found = false;
   720       for (int j = 0; j < owned_monitors_list->length(); j++) {
   721         jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
   722         oop check = JNIHandles::resolve(jobj);
   723         if (check == obj) {
   724           found = true;  // we found the object
   725           break;
   726         }
   727       }
   729       if (found) {
   730         // already have this object so don't include it
   731         continue;
   732       }
   733     }
   735     // add the owning object to our list
   736     jvmtiMonitorStackDepthInfo *jmsdi;
   737     err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
   738     if (err != JVMTI_ERROR_NONE) {
   739         return err;
   740     }
   741     Handle hobj(obj);
   742     jmsdi->monitor = jni_reference(calling_thread, hobj);
   743     jmsdi->stack_depth = stack_depth;
   744     owned_monitors_list->append(jmsdi);
   745   }
   747   return err;
   748 }
   750 jvmtiError
   751 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
   752                               jint start_depth, jint max_count,
   753                               jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
   754 #ifdef ASSERT
   755   uint32_t debug_bits = 0;
   756 #endif
   757   assert((SafepointSynchronize::is_at_safepoint() ||
   758           is_thread_fully_suspended(java_thread, false, &debug_bits)),
   759          "at safepoint or target thread is suspended");
   760   int count = 0;
   761   if (java_thread->has_last_Java_frame()) {
   762     RegisterMap reg_map(java_thread);
   763     Thread* current_thread = Thread::current();
   764     ResourceMark rm(current_thread);
   765     javaVFrame *jvf = java_thread->last_java_vframe(&reg_map);
   766     HandleMark hm(current_thread);
   767     if (start_depth != 0) {
   768       if (start_depth > 0) {
   769         for (int j = 0; j < start_depth && jvf != NULL; j++) {
   770           jvf = jvf->java_sender();
   771         }
   772         if (jvf == NULL) {
   773           // start_depth is deeper than the stack depth
   774           return JVMTI_ERROR_ILLEGAL_ARGUMENT;
   775         }
   776       } else { // start_depth < 0
   777         // we are referencing the starting depth based on the oldest
   778         // part of the stack.
   779         // optimize to limit the number of times that java_sender() is called
   780         javaVFrame *jvf_cursor = jvf;
   781         javaVFrame *jvf_prev = NULL;
   782         javaVFrame *jvf_prev_prev;
   783         int j = 0;
   784         while (jvf_cursor != NULL) {
   785           jvf_prev_prev = jvf_prev;
   786           jvf_prev = jvf_cursor;
   787           for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
   788             jvf_cursor = jvf_cursor->java_sender();
   789           }
   790         }
   791         if (j == start_depth) {
   792           // previous pointer is exactly where we want to start
   793           jvf = jvf_prev;
   794         } else {
   795           // we need to back up further to get to the right place
   796           if (jvf_prev_prev == NULL) {
   797             // the -start_depth is greater than the stack depth
   798             return JVMTI_ERROR_ILLEGAL_ARGUMENT;
   799           }
   800           // j now is the number of frames on the stack starting with
   801           // jvf_prev, we start from jvf_prev_prev and move older on
   802           // the stack that many, the result is -start_depth frames
   803           // remaining.
   804           jvf = jvf_prev_prev;
   805           for (; j < 0; j++) {
   806             jvf = jvf->java_sender();
   807           }
   808         }
   809       }
   810     }
   811     for (; count < max_count && jvf != NULL; count++) {
   812       frame_buffer[count].method = jvf->method()->jmethod_id();
   813       frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
   814       jvf = jvf->java_sender();
   815     }
   816   } else {
   817     if (start_depth != 0) {
   818       // no frames and there is a starting depth
   819       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
   820     }
   821   }
   822   *count_ptr = count;
   823   return JVMTI_ERROR_NONE;
   824 }
   826 jvmtiError
   827 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
   828   assert((state != NULL),
   829          "JavaThread should create JvmtiThreadState before calling this method");
   830   *count_ptr = state->count_frames();
   831   return JVMTI_ERROR_NONE;
   832 }
   834 jvmtiError
   835 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
   836                                  jmethodID* method_ptr, jlocation* location_ptr) {
   837 #ifdef ASSERT
   838   uint32_t debug_bits = 0;
   839 #endif
   840   assert((SafepointSynchronize::is_at_safepoint() ||
   841           is_thread_fully_suspended(java_thread, false, &debug_bits)),
   842          "at safepoint or target thread is suspended");
   843   Thread* current_thread = Thread::current();
   844   ResourceMark rm(current_thread);
   846   vframe *vf = vframeFor(java_thread, depth);
   847   if (vf == NULL) {
   848     return JVMTI_ERROR_NO_MORE_FRAMES;
   849   }
   851   // vframeFor should return a java frame. If it doesn't
   852   // it means we've got an internal error and we return the
   853   // error in product mode. In debug mode we will instead
   854   // attempt to cast the vframe to a javaVFrame and will
   855   // cause an assertion/crash to allow further diagnosis.
   856 #ifdef PRODUCT
   857   if (!vf->is_java_frame()) {
   858     return JVMTI_ERROR_INTERNAL;
   859   }
   860 #endif
   862   HandleMark hm(current_thread);
   863   javaVFrame *jvf = javaVFrame::cast(vf);
   864   methodOop method = jvf->method();
   865   if (method->is_native()) {
   866     *location_ptr = -1;
   867   } else {
   868     *location_ptr = jvf->bci();
   869   }
   870   *method_ptr = method->jmethod_id();
   872   return JVMTI_ERROR_NONE;
   873 }
   876 jvmtiError
   877 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
   878   HandleMark hm;
   879   Handle hobj;
   881   bool at_safepoint = SafepointSynchronize::is_at_safepoint();
   883   // Check arguments
   884   {
   885     oop mirror = JNIHandles::resolve_external_guard(object);
   886     NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
   887     NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
   889     hobj = Handle(mirror);
   890   }
   892   JavaThread *owning_thread = NULL;
   893   ObjectMonitor *mon = NULL;
   894   jvmtiMonitorUsage ret = {
   895       NULL, 0, 0, NULL, 0, NULL
   896   };
   898   uint32_t debug_bits = 0;
   899   // first derive the object's owner and entry_count (if any)
   900   {
   901     // Revoke any biases before querying the mark word
   902     if (SafepointSynchronize::is_at_safepoint()) {
   903       BiasedLocking::revoke_at_safepoint(hobj);
   904     } else {
   905       BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
   906     }
   908     address owner = NULL;
   909     {
   910       markOop mark = hobj()->mark();
   912       if (!mark->has_monitor()) {
   913         // this object has a lightweight monitor
   915         if (mark->has_locker()) {
   916           owner = (address)mark->locker(); // save the address of the Lock word
   917         }
   918         // implied else: no owner
   919       } else {
   920         // this object has a heavyweight monitor
   921         mon = mark->monitor();
   923         // The owner field of a heavyweight monitor may be NULL for no
   924         // owner, a JavaThread * or it may still be the address of the
   925         // Lock word in a JavaThread's stack. A monitor can be inflated
   926         // by a non-owning JavaThread, but only the owning JavaThread
   927         // can change the owner field from the Lock word to the
   928         // JavaThread * and it may not have done that yet.
   929         owner = (address)mon->owner();
   930       }
   931     }
   933     if (owner != NULL) {
   934       // This monitor is owned so we have to find the owning JavaThread.
   935       // Since owning_thread_from_monitor_owner() grabs a lock, GC can
   936       // move our object at this point. However, our owner value is safe
   937       // since it is either the Lock word on a stack or a JavaThread *.
   938       owning_thread = Threads::owning_thread_from_monitor_owner(owner, !at_safepoint);
   939       assert(owning_thread != NULL, "sanity check");
   940       if (owning_thread != NULL) {  // robustness
   941         // The monitor's owner either has to be the current thread, at safepoint
   942         // or it has to be suspended. Any of these conditions will prevent both
   943         // contending and waiting threads from modifying the state of
   944         // the monitor.
   945         if (!at_safepoint && !JvmtiEnv::is_thread_fully_suspended(owning_thread, true, &debug_bits)) {
   946           return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
   947         }
   948         HandleMark hm;
   949         Handle     th(owning_thread->threadObj());
   950         ret.owner = (jthread)jni_reference(calling_thread, th);
   951       }
   952       // implied else: no owner
   953     }
   955     if (owning_thread != NULL) {  // monitor is owned
   956       if ((address)owning_thread == owner) {
   957         // the owner field is the JavaThread *
   958         assert(mon != NULL,
   959           "must have heavyweight monitor with JavaThread * owner");
   960         ret.entry_count = mon->recursions() + 1;
   961       } else {
   962         // The owner field is the Lock word on the JavaThread's stack
   963         // so the recursions field is not valid. We have to count the
   964         // number of recursive monitor entries the hard way. We pass
   965         // a handle to survive any GCs along the way.
   966         ResourceMark rm;
   967         ret.entry_count = count_locked_objects(owning_thread, hobj);
   968       }
   969     }
   970     // implied else: entry_count == 0
   971   }
   973   int nWant,nWait;
   974   if (mon != NULL) {
   975     // this object has a heavyweight monitor
   976     nWant = mon->contentions(); // # of threads contending for monitor
   977     nWait = mon->waiters();     // # of threads in Object.wait()
   978     ret.waiter_count = nWant + nWait;
   979     ret.notify_waiter_count = nWait;
   980   } else {
   981     // this object has a lightweight monitor
   982     ret.waiter_count = 0;
   983     ret.notify_waiter_count = 0;
   984   }
   986   // Allocate memory for heavyweight and lightweight monitor.
   987   jvmtiError err;
   988   err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
   989   if (err != JVMTI_ERROR_NONE) {
   990     return err;
   991   }
   992   err = allocate(ret.notify_waiter_count * sizeof(jthread *),
   993                  (unsigned char**)&ret.notify_waiters);
   994   if (err != JVMTI_ERROR_NONE) {
   995     deallocate((unsigned char*)ret.waiters);
   996     return err;
   997   }
   999   // now derive the rest of the fields
  1000   if (mon != NULL) {
  1001     // this object has a heavyweight monitor
  1003     // Number of waiters may actually be less than the waiter count.
  1004     // So NULL out memory so that unused memory will be NULL.
  1005     memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
  1006     memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
  1008     if (ret.waiter_count > 0) {
  1009       // we have contending and/or waiting threads
  1010       HandleMark hm;
  1011       if (nWant > 0) {
  1012         // we have contending threads
  1013         ResourceMark rm;
  1014         // get_pending_threads returns only java thread so we do not need to
  1015         // check for  non java threads.
  1016         GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(
  1017           nWant, (address)mon, !at_safepoint);
  1018         if (wantList->length() < nWant) {
  1019           // robustness: the pending list has gotten smaller
  1020           nWant = wantList->length();
  1022         for (int i = 0; i < nWant; i++) {
  1023           JavaThread *pending_thread = wantList->at(i);
  1024           // If the monitor has no owner, then a non-suspended contending
  1025           // thread could potentially change the state of the monitor by
  1026           // entering it. The JVM/TI spec doesn't allow this.
  1027           if (owning_thread == NULL && !at_safepoint &
  1028               !JvmtiEnv::is_thread_fully_suspended(pending_thread, true, &debug_bits)) {
  1029             if (ret.owner != NULL) {
  1030               destroy_jni_reference(calling_thread, ret.owner);
  1032             for (int j = 0; j < i; j++) {
  1033               destroy_jni_reference(calling_thread, ret.waiters[j]);
  1035             deallocate((unsigned char*)ret.waiters);
  1036             deallocate((unsigned char*)ret.notify_waiters);
  1037             return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
  1039           Handle th(pending_thread->threadObj());
  1040           ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
  1043       if (nWait > 0) {
  1044         // we have threads in Object.wait()
  1045         int offset = nWant;  // add after any contending threads
  1046         ObjectWaiter *waiter = mon->first_waiter();
  1047         for (int i = 0, j = 0; i < nWait; i++) {
  1048           if (waiter == NULL) {
  1049             // robustness: the waiting list has gotten smaller
  1050             nWait = j;
  1051             break;
  1053           Thread *t = mon->thread_of_waiter(waiter);
  1054           if (t != NULL && t->is_Java_thread()) {
  1055             JavaThread *wjava_thread = (JavaThread *)t;
  1056             // If the thread was found on the ObjectWaiter list, then
  1057             // it has not been notified. This thread can't change the
  1058             // state of the monitor so it doesn't need to be suspended.
  1059             Handle th(wjava_thread->threadObj());
  1060             ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
  1061             ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
  1063           waiter = mon->next_waiter(waiter);
  1068     // Adjust count. nWant and nWait count values may be less than original.
  1069     ret.waiter_count = nWant + nWait;
  1070     ret.notify_waiter_count = nWait;
  1071   } else {
  1072     // this object has a lightweight monitor and we have nothing more
  1073     // to do here because the defaults are just fine.
  1076   // we don't update return parameter unless everything worked
  1077   *info_ptr = ret;
  1079   return JVMTI_ERROR_NONE;
  1082 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
  1083   _env = env;
  1084   _allocations = new (ResourceObj::C_HEAP) GrowableArray<unsigned char*>(20, true);
  1085   _failed = false;
  1087 ResourceTracker::~ResourceTracker() {
  1088   if (_failed) {
  1089     for (int i=0; i<_allocations->length(); i++) {
  1090       _env->deallocate(_allocations->at(i));
  1093   delete _allocations;
  1096 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
  1097   unsigned char *ptr;
  1098   jvmtiError err = _env->allocate(size, &ptr);
  1099   if (err == JVMTI_ERROR_NONE) {
  1100     _allocations->append(ptr);
  1101     *mem_ptr = ptr;
  1102   } else {
  1103     *mem_ptr = NULL;
  1104     _failed = true;
  1106   return err;
  1109 unsigned char* ResourceTracker::allocate(jlong size) {
  1110   unsigned char* ptr;
  1111   allocate(size, &ptr);
  1112   return ptr;
  1115 char* ResourceTracker::strdup(const char* str) {
  1116   char *dup_str = (char*)allocate(strlen(str)+1);
  1117   if (dup_str != NULL) {
  1118     strcpy(dup_str, str);
  1120   return dup_str;
  1123 struct StackInfoNode {
  1124   struct StackInfoNode *next;
  1125   jvmtiStackInfo info;
  1126 };
  1128 // Create a jvmtiStackInfo inside a linked list node and create a
  1129 // buffer for the frame information, both allocated as resource objects.
  1130 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
  1131 // Note that either or both of thr and thread_oop
  1132 // may be null if the thread is new or has exited.
  1133 void
  1134 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
  1135   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1137   jint state = 0;
  1138   struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
  1139   jvmtiStackInfo *infop = &(node->info);
  1140   node->next = head();
  1141   set_head(node);
  1142   infop->frame_count = 0;
  1143   infop->thread = jt;
  1145   if (thread_oop != NULL) {
  1146     // get most state bits
  1147     state = (jint)java_lang_Thread::get_thread_status(thread_oop);
  1150   if (thr != NULL) {    // add more state bits if there is a JavaThead to query
  1151     // same as is_being_ext_suspended() but without locking
  1152     if (thr->is_ext_suspended() || thr->is_external_suspend()) {
  1153       state |= JVMTI_THREAD_STATE_SUSPENDED;
  1155     JavaThreadState jts = thr->thread_state();
  1156     if (jts == _thread_in_native) {
  1157       state |= JVMTI_THREAD_STATE_IN_NATIVE;
  1159     OSThread* osThread = thr->osthread();
  1160     if (osThread != NULL && osThread->interrupted()) {
  1161       state |= JVMTI_THREAD_STATE_INTERRUPTED;
  1164   infop->state = state;
  1166   if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
  1167     infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
  1168     env()->get_stack_trace(thr, 0, max_frame_count(),
  1169                            infop->frame_buffer, &(infop->frame_count));
  1170   } else {
  1171     infop->frame_buffer = NULL;
  1172     infop->frame_count = 0;
  1174   _frame_count_total += infop->frame_count;
  1177 // Based on the stack information in the linked list, allocate memory
  1178 // block to return and fill it from the info in the linked list.
  1179 void
  1180 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
  1181   // do I need to worry about alignment issues?
  1182   jlong alloc_size =  thread_count       * sizeof(jvmtiStackInfo)
  1183                     + _frame_count_total * sizeof(jvmtiFrameInfo);
  1184   env()->allocate(alloc_size, (unsigned char **)&_stack_info);
  1186   // pointers to move through the newly allocated space as it is filled in
  1187   jvmtiStackInfo *si = _stack_info + thread_count;      // bottom of stack info
  1188   jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si;            // is the top of frame info
  1190   // copy information in resource area into allocated buffer
  1191   // insert stack info backwards since linked list is backwards
  1192   // insert frame info forwards
  1193   // walk the StackInfoNodes
  1194   for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
  1195     jint frame_count = sin->info.frame_count;
  1196     size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
  1197     --si;
  1198     memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
  1199     if (frames_size == 0) {
  1200       si->frame_buffer = NULL;
  1201     } else {
  1202       memcpy(fi, sin->info.frame_buffer, frames_size);
  1203       si->frame_buffer = fi;  // point to the new allocated copy of the frames
  1204       fi += frame_count;
  1207   assert(si == _stack_info, "the last copied stack info must be the first record");
  1208   assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
  1209          "the last copied frame info must be the last record");
  1213 void
  1214 VM_GetThreadListStackTraces::doit() {
  1215   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1217   ResourceMark rm;
  1218   for (int i = 0; i < _thread_count; ++i) {
  1219     jthread jt = _thread_list[i];
  1220     oop thread_oop = JNIHandles::resolve_external_guard(jt);
  1221     if (thread_oop == NULL || !thread_oop->is_a(SystemDictionary::thread_klass())) {
  1222       set_result(JVMTI_ERROR_INVALID_THREAD);
  1223       return;
  1225     fill_frames(jt, java_lang_Thread::thread(thread_oop), thread_oop);
  1227   allocate_and_fill_stacks(_thread_count);
  1230 void
  1231 VM_GetAllStackTraces::doit() {
  1232   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  1234   ResourceMark rm;
  1235   _final_thread_count = 0;
  1236   for (JavaThread *jt = Threads::first(); jt != NULL; jt = jt->next()) {
  1237     oop thread_oop = jt->threadObj();
  1238     if (thread_oop != NULL &&
  1239         !jt->is_exiting() &&
  1240         java_lang_Thread::is_alive(thread_oop) &&
  1241         !jt->is_hidden_from_external_view()) {
  1242       ++_final_thread_count;
  1243       // Handle block of the calling thread is used to create local refs.
  1244       fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
  1245                   jt, thread_oop);
  1248   allocate_and_fill_stacks(_final_thread_count);
  1251 // Verifies that the top frame is a java frame in an expected state.
  1252 // Deoptimizes frame if needed.
  1253 // Checks that the frame method signature matches the return type (tos).
  1254 // HandleMark must be defined in the caller only.
  1255 // It is to keep a ret_ob_h handle alive after return to the caller.
  1256 jvmtiError
  1257 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
  1258                               jvalue value, TosState tos, Handle* ret_ob_h) {
  1259   ResourceMark rm(current_thread);
  1261   vframe *vf = vframeFor(java_thread, 0);
  1262   NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
  1264   javaVFrame *jvf = (javaVFrame*) vf;
  1265   if (!vf->is_java_frame() || jvf->method()->is_native()) {
  1266     return JVMTI_ERROR_OPAQUE_FRAME;
  1269   // If the frame is a compiled one, need to deoptimize it.
  1270   if (vf->is_compiled_frame()) {
  1271     if (!vf->fr().can_be_deoptimized()) {
  1272       return JVMTI_ERROR_OPAQUE_FRAME;
  1274     VM_DeoptimizeFrame deopt(java_thread, jvf->fr().id());
  1275     VMThread::execute(&deopt);
  1278   // Get information about method return type
  1279   symbolHandle signature(current_thread, jvf->method()->signature());
  1281   ResultTypeFinder rtf(signature);
  1282   TosState fr_tos = as_TosState(rtf.type());
  1283   if (fr_tos != tos) {
  1284     if (tos != itos || (fr_tos != btos && fr_tos != ctos && fr_tos != stos)) {
  1285       return JVMTI_ERROR_TYPE_MISMATCH;
  1289   // Check that the jobject class matches the return type signature.
  1290   jobject jobj = value.l;
  1291   if (tos == atos && jobj != NULL) { // NULL reference is allowed
  1292     Handle ob_h = Handle(current_thread, JNIHandles::resolve_external_guard(jobj));
  1293     NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
  1294     KlassHandle ob_kh = KlassHandle(current_thread, ob_h()->klass());
  1295     NULL_CHECK(ob_kh, JVMTI_ERROR_INVALID_OBJECT);
  1297     // Method return type signature.
  1298     char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
  1300     if (!VM_GetOrSetLocal::is_assignable(ty_sign, Klass::cast(ob_kh()), current_thread)) {
  1301       return JVMTI_ERROR_TYPE_MISMATCH;
  1303     *ret_ob_h = ob_h;
  1305   return JVMTI_ERROR_NONE;
  1306 } /* end check_top_frame */
  1309 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
  1310 // Main difference is on the last stage in the interpreter.
  1311 // The PopFrame stops method execution to continue execution
  1312 // from the same method call instruction.
  1313 // The ForceEarlyReturn forces return from method so the execution
  1314 // continues at the bytecode following the method call.
  1316 // Threads_lock NOT held, java_thread not protected by lock
  1317 // java_thread - pre-checked
  1319 jvmtiError
  1320 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
  1321   JavaThread* current_thread = JavaThread::current();
  1322   HandleMark   hm(current_thread);
  1323   uint32_t debug_bits = 0;
  1325   // Check if java_thread is fully suspended
  1326   if (!is_thread_fully_suspended(java_thread,
  1327                                  true /* wait for suspend completion */,
  1328                                  &debug_bits)) {
  1329     return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
  1332   // retreive or create the state
  1333   JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
  1335   // Check to see if a ForceEarlyReturn was already in progress
  1336   if (state->is_earlyret_pending()) {
  1337     // Probably possible for JVMTI clients to trigger this, but the
  1338     // JPDA backend shouldn't allow this to happen
  1339     return JVMTI_ERROR_INTERNAL;
  1342     // The same as for PopFrame. Workaround bug:
  1343     //  4812902: popFrame hangs if the method is waiting at a synchronize
  1344     // Catch this condition and return an error to avoid hanging.
  1345     // Now JVMTI spec allows an implementation to bail out with an opaque
  1346     // frame error.
  1347     OSThread* osThread = java_thread->osthread();
  1348     if (osThread->get_state() == MONITOR_WAIT) {
  1349       return JVMTI_ERROR_OPAQUE_FRAME;
  1352   Handle ret_ob_h = Handle();
  1353   jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
  1354   if (err != JVMTI_ERROR_NONE) {
  1355     return err;
  1357   assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
  1358          "return object oop must not be NULL if jobject is not NULL");
  1360   // Update the thread state to reflect that the top frame must be
  1361   // forced to return.
  1362   // The current frame will be returned later when the suspended
  1363   // thread is resumed and right before returning from VM to Java.
  1364   // (see call_VM_base() in assembler_<cpu>.cpp).
  1366   state->set_earlyret_pending();
  1367   state->set_earlyret_oop(ret_ob_h());
  1368   state->set_earlyret_value(value, tos);
  1370   // Set pending step flag for this early return.
  1371   // It is cleared when next step event is posted.
  1372   state->set_pending_step_for_earlyret();
  1374   return JVMTI_ERROR_NONE;
  1375 } /* end force_early_return */
  1377 void
  1378 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
  1379   if ( _error != JVMTI_ERROR_NONE) {
  1380     // Error occurred in previous iteration so no need to add
  1381     // to the list.
  1382     return;
  1384   if (mon->owner() == _java_thread ) {
  1385     // Filter out on stack monitors collected during stack walk.
  1386     oop obj = (oop)mon->object();
  1387     bool found = false;
  1388     for (int j = 0; j < _owned_monitors_list->length(); j++) {
  1389       jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
  1390       oop check = JNIHandles::resolve(jobj);
  1391       if (check == obj) {
  1392         // On stack monitor already collected during the stack walk.
  1393         found = true;
  1394         break;
  1397     if (found == false) {
  1398       // This is off stack monitor (e.g. acquired via jni MonitorEnter).
  1399       jvmtiError err;
  1400       jvmtiMonitorStackDepthInfo *jmsdi;
  1401       err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
  1402       if (err != JVMTI_ERROR_NONE) {
  1403         _error = err;
  1404         return;
  1406       Handle hobj(obj);
  1407       jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
  1408       // stack depth is unknown for this monitor.
  1409       jmsdi->stack_depth = -1;
  1410       _owned_monitors_list->append(jmsdi);
  1415 #endif // !JVMTI_KERNEL

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