jdk8-mips64-public/hotspot: src/share/vm/prims/jvmtiEnvBase.cpp@04ff2f6cd0eb (annotated)

src/share/vm/prims/jvmtiEnvBase.cpp@04ff2f6cd0eb (annotated)

src/share/vm/prims/jvmtiEnvBase.cpp

Tue, 17 Oct 2017 12:58:25 +0800

author: aoqi
date: Tue, 17 Oct 2017 12:58:25 +0800
changeset 7994: 04ff2f6cd0eb
parent 7535: 7ae4e26cb1e0
child 8604: 04d83ba48607
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "jvmtifiles/jvmtiEnv.hpp"
 #include "oops/objArrayKlass.hpp"
 #include "oops/objArrayOop.hpp"
 #include "prims/jvmtiEnvBase.hpp"
 #include "prims/jvmtiEventController.inline.hpp"
 #include "prims/jvmtiExtensions.hpp"
 #include "prims/jvmtiImpl.hpp"
 #include "prims/jvmtiManageCapabilities.hpp"
 #include "prims/jvmtiTagMap.hpp"
 #include "prims/jvmtiThreadState.inline.hpp"
 #include "runtime/biasedLocking.hpp"
 #include "runtime/deoptimization.hpp"
 #include "runtime/interfaceSupport.hpp"
 #include "runtime/jfieldIDWorkaround.hpp"
 #include "runtime/objectMonitor.hpp"
 #include "runtime/objectMonitor.inline.hpp"
 #include "runtime/signature.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/vframe.hpp"
 #include "runtime/vframe_hp.hpp"
 #include "runtime/vmThread.hpp"
 #include "runtime/vm_operations.hpp"
 ///////////////////////////////////////////////////////////////
 //
 // JvmtiEnvBase
 //
 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
 bool JvmtiEnvBase::_globally_initialized = false;
 volatile bool JvmtiEnvBase::_needs_clean_up = false;
 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
 extern jvmtiInterface_1_ jvmti_Interface;
 extern jvmtiInterface_1_ jvmtiTrace_Interface;
 // perform initializations that must occur before any JVMTI environments
 // are released but which should only be initialized once (no matter
 // how many environments are created).
 void
 JvmtiEnvBase::globally_initialize() {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   assert(_globally_initialized == false, "bad call");
   JvmtiManageCapabilities::initialize();
   // register extension functions and events
   JvmtiExtensions::register_extensions();
 #ifdef JVMTI_TRACE
   JvmtiTrace::initialize();
 #endif
   _globally_initialized = true;
 }
 void
 JvmtiEnvBase::initialize() {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   // Add this environment to the end of the environment list (order is important)
   {
     // This block of code must not contain any safepoints, as list deallocation
     // (which occurs at a safepoint) cannot occur simultaneously with this list
     // addition.  Note: No_Safepoint_Verifier cannot, currently, be used before
     // threads exist.
     JvmtiEnvIterator it;
     JvmtiEnvBase *previous_env = NULL;
     for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
       previous_env = env;
     }
     if (previous_env == NULL) {
       _head_environment = this;
     } else {
       previous_env->set_next_environment(this);
     }
   }
   if (_globally_initialized == false) {
     globally_initialize();
   }
 }
 bool
 JvmtiEnvBase::is_valid() {
   jint value = 0;
   // This object might not be a JvmtiEnvBase so we can't assume
   // the _magic field is properly aligned. Get the value in a safe
   // way and then check against JVMTI_MAGIC.
   switch (sizeof(_magic)) {
   case 2:
     value = Bytes::get_native_u2((address)&_magic);
     break;
   case 4:
     value = Bytes::get_native_u4((address)&_magic);
     break;
   case 8:
     value = Bytes::get_native_u8((address)&_magic);
     break;
   default:
     guarantee(false, "_magic field is an unexpected size");
   }
   return value == JVMTI_MAGIC;
 }
 bool
 JvmtiEnvBase::use_version_1_0_semantics() {
   int major, minor, micro;
   JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
   return major == 1 && minor == 0;  // micro version doesn't matter here
 }
 bool
 JvmtiEnvBase::use_version_1_1_semantics() {
   int major, minor, micro;
   JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
   return major == 1 && minor == 1;  // micro version doesn't matter here
 }
 bool
 JvmtiEnvBase::use_version_1_2_semantics() {
   int major, minor, micro;
   JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
   return major == 1 && minor == 2;  // micro version doesn't matter here
 }
 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
   _version = version;
   _env_local_storage = NULL;
   _tag_map = NULL;
   _native_method_prefix_count = 0;
   _native_method_prefixes = NULL;
   _next = NULL;
   _class_file_load_hook_ever_enabled = false;
   // Moot since ClassFileLoadHook not yet enabled.
   // But "true" will give a more predictable ClassFileLoadHook behavior
   // for environment creation during ClassFileLoadHook.
   _is_retransformable = true;
   // all callbacks initially NULL
   memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
   // all capabilities initially off
   memset(&_current_capabilities, 0, sizeof(_current_capabilities));
   // all prohibited capabilities initially off
   memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
   _magic = JVMTI_MAGIC;
   JvmtiEventController::env_initialize((JvmtiEnv*)this);
 #ifdef JVMTI_TRACE
   _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
 #else
   _jvmti_external.functions = &jvmti_Interface;
 #endif
 }
 void
 JvmtiEnvBase::dispose() {
 #ifdef JVMTI_TRACE
   JvmtiTrace::shutdown();
 #endif
   // Dispose of event info and let the event controller call us back
   // in a locked state (env_dispose, below)
   JvmtiEventController::env_dispose(this);
 }
 void
 JvmtiEnvBase::env_dispose() {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   // We have been entered with all events disabled on this environment.
   // A race to re-enable events (by setting callbacks) is prevented by
   // checking for a valid environment when setting callbacks (while
   // holding the JvmtiThreadState_lock).
   // Mark as invalid.
   _magic = DISPOSED_MAGIC;
   // Relinquish all capabilities.
   jvmtiCapabilities *caps = get_capabilities();
   JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
   // Same situation as with events (see above)
   set_native_method_prefixes(0, NULL);
   JvmtiTagMap* tag_map_to_deallocate = _tag_map;
   set_tag_map(NULL);
   // A tag map can be big, deallocate it now
   if (tag_map_to_deallocate != NULL) {
     delete tag_map_to_deallocate;
   }
   _needs_clean_up = true;
 }
 JvmtiEnvBase::~JvmtiEnvBase() {
   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   // There is a small window of time during which the tag map of a
   // disposed environment could have been reallocated.
   // Make sure it is gone.
   JvmtiTagMap* tag_map_to_deallocate = _tag_map;
   set_tag_map(NULL);
   // A tag map can be big, deallocate it now
   if (tag_map_to_deallocate != NULL) {
     delete tag_map_to_deallocate;
   }
   _magic = BAD_MAGIC;
 }
 void
 JvmtiEnvBase::periodic_clean_up() {
   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
   // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
   JvmtiThreadState::periodic_clean_up();
   // Unlink all invalid environments from the list of environments
   // and deallocate them
   JvmtiEnvIterator it;
   JvmtiEnvBase* previous_env = NULL;
   JvmtiEnvBase* env = it.first();
   while (env != NULL) {
     if (env->is_valid()) {
       previous_env = env;
       env = it.next(env);
     } else {
       // This one isn't valid, remove it from the list and deallocate it
       JvmtiEnvBase* defunct_env = env;
       env = it.next(env);
       if (previous_env == NULL) {
         _head_environment = env;
       } else {
         previous_env->set_next_environment(env);
       }
       delete defunct_env;
     }
   }
 }
 void
 JvmtiEnvBase::check_for_periodic_clean_up() {
   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
   class ThreadInsideIterationClosure: public ThreadClosure {
    private:
     bool _inside;
    public:
     ThreadInsideIterationClosure() : _inside(false) {};
     void do_thread(Thread* thread) {
       _inside |= thread->is_inside_jvmti_env_iteration();
     }
     bool is_inside_jvmti_env_iteration() {
       return _inside;
     }
   };
   if (_needs_clean_up) {
     // Check if we are currently iterating environment,
     // deallocation should not occur if we are
     ThreadInsideIterationClosure tiic;
     Threads::threads_do(&tiic);
     if (!tiic.is_inside_jvmti_env_iteration() &&
              !is_inside_dying_thread_env_iteration()) {
       _needs_clean_up = false;
       JvmtiEnvBase::periodic_clean_up();
     }
   }
 }
 void
 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
          "sanity check");
   if (!_class_file_load_hook_ever_enabled) {
     _class_file_load_hook_ever_enabled = true;
     if (get_capabilities()->can_retransform_classes) {
       _is_retransformable = true;
     } else {
       _is_retransformable = false;
       // cannot add retransform capability after ClassFileLoadHook has been enabled
       get_prohibited_capabilities()->can_retransform_classes = 1;
     }
   }
 }
 void
 JvmtiEnvBase::record_class_file_load_hook_enabled() {
   if (!_class_file_load_hook_ever_enabled) {
     if (Threads::number_of_threads() == 0) {
       record_first_time_class_file_load_hook_enabled();
     } else {
       MutexLocker mu(JvmtiThreadState_lock);
       record_first_time_class_file_load_hook_enabled();
     }
   }
 }
 jvmtiError
 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
          "sanity check");
   int old_prefix_count = get_native_method_prefix_count();
   char **old_prefixes = get_native_method_prefixes();
   // allocate and install the new prefixex
   if (prefix_count == 0 || !is_valid()) {
     _native_method_prefix_count = 0;
     _native_method_prefixes = NULL;
   } else {
     // there are prefixes, allocate an array to hold them, and fill it
     char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
     if (new_prefixes == NULL) {
       return JVMTI_ERROR_OUT_OF_MEMORY;
     }
     for (int i = 0; i < prefix_count; i++) {
       char* prefix = prefixes[i];
       if (prefix == NULL) {
         for (int j = 0; j < (i-1); j++) {
           os::free(new_prefixes[j]);
         }
         os::free(new_prefixes);
         return JVMTI_ERROR_NULL_POINTER;
       }
       prefix = os::strdup(prefixes[i]);
       if (prefix == NULL) {
         for (int j = 0; j < (i-1); j++) {
           os::free(new_prefixes[j]);
         }
         os::free(new_prefixes);
         return JVMTI_ERROR_OUT_OF_MEMORY;
       }
       new_prefixes[i] = prefix;
     }
     _native_method_prefix_count = prefix_count;
     _native_method_prefixes = new_prefixes;
   }
   // now that we know the new prefixes have been successfully installed we can
   // safely remove the old ones
   if (old_prefix_count != 0) {
     for (int i = 0; i < old_prefix_count; i++) {
       os::free(old_prefixes[i]);
     }
     os::free(old_prefixes);
   }
   return JVMTI_ERROR_NONE;
 }
 // Collect all the prefixes which have been set in any JVM TI environments
 // by the SetNativeMethodPrefix(es) functions.  Be sure to maintain the
 // order of environments and the order of prefixes within each environment.
 // Return in a resource allocated array.
 char**
 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
   assert(Threads::number_of_threads() == 0 ||
          SafepointSynchronize::is_at_safepoint() ||
          JvmtiThreadState_lock->is_locked(),
          "sanity check");
   int total_count = 0;
   GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
   JvmtiEnvIterator it;
   for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
     int prefix_count = env->get_native_method_prefix_count();
     char** prefixes = env->get_native_method_prefixes();
     for (int j = 0; j < prefix_count; j++) {
       // retrieve a prefix and so that it is safe against asynchronous changes
       // copy it into the resource area
       char* prefix = prefixes[j];
       char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
       strcpy(prefix_copy, prefix);
       prefix_array->at_put_grow(total_count++, prefix_copy);
     }
   }
   char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
   char** p = all_prefixes;
   for (int i = 0; i < total_count; ++i) {
     *p++ = prefix_array->at(i);
   }
   *count_ptr = total_count;
   return all_prefixes;
 }
 void
 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
                                                jint size_of_callbacks) {
   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
   size_t byte_cnt = sizeof(jvmtiEventCallbacks);
   // clear in either case to be sure we got any gap between sizes
   memset(&_event_callbacks, 0, byte_cnt);
   // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
   // are re-enabled by a call to set event callbacks where the DisposeEnvironment
   // occurs after the boiler-plate environment check and before the lock is acquired.
   if (callbacks != NULL && is_valid()) {
     if (size_of_callbacks < (jint)byte_cnt) {
       byte_cnt = size_of_callbacks;
     }
     memcpy(&_event_callbacks, callbacks, byte_cnt);
   }
 }
 // Called from JVMTI entry points which perform stack walking. If the
 // associated JavaThread is the current thread, then wait_for_suspend
 // is not used. Otherwise, it determines if we should wait for the
 // "other" thread to complete external suspension. (NOTE: in future
 // releases the suspension mechanism should be reimplemented so this
 // is not necessary.)
 //
 bool
 JvmtiEnvBase::is_thread_fully_suspended(JavaThread* thr, bool wait_for_suspend, uint32_t *bits) {
   // "other" threads require special handling
   if (thr != JavaThread::current()) {
     if (wait_for_suspend) {
       // We are allowed to wait for the external suspend to complete
       // so give the other thread a chance to get suspended.
       if (!thr->wait_for_ext_suspend_completion(SuspendRetryCount,
           SuspendRetryDelay, bits)) {
         // didn't make it so let the caller know
         return false;
       }
     }
     // We aren't allowed to wait for the external suspend to complete
     // so if the other thread isn't externally suspended we need to
     // let the caller know.
     else if (!thr->is_ext_suspend_completed_with_lock(bits)) {
       return false;
     }
   }
   return true;
 }
 // In the fullness of time, all users of the method should instead
 // directly use allocate, besides being cleaner and faster, this will
 // mean much better out of memory handling
 unsigned char *
 JvmtiEnvBase::jvmtiMalloc(jlong size) {
   unsigned char* mem;
   jvmtiError result = allocate(size, &mem);
   assert(result == JVMTI_ERROR_NONE, "Allocate failed");
   return mem;
 }
 //
 // Threads
 //
 jobject *
 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
   if (length == 0) {
     return NULL;
   }
   jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
   NULL_CHECK(objArray, NULL);
   for (int i=0; i<length; i++) {
     objArray[i] = jni_reference(handles[i]);
   }
   return objArray;
 }
 jthread *
 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
   return (jthread *) new_jobjectArray(length,handles);
 }
 jthreadGroup *
 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
   return (jthreadGroup *) new_jobjectArray(length,handles);
 }
 JavaThread *
 JvmtiEnvBase::get_JavaThread(jthread jni_thread) {
   oop t = JNIHandles::resolve_external_guard(jni_thread);
   if (t == NULL || !t->is_a(SystemDictionary::Thread_klass())) {
     return NULL;
   }
   // The following returns NULL if the thread has not yet run or is in
   // process of exiting
   return java_lang_Thread::thread(t);
 }
 // return the vframe on the specified thread and depth, NULL if no such frame
 vframe*
 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
   if (!java_thread->has_last_Java_frame()) {
     return NULL;
   }
   RegisterMap reg_map(java_thread);
   vframe *vf = java_thread->last_java_vframe(&reg_map);
   int d = 0;
   while ((vf != NULL) && (d < depth)) {
     vf = vf->java_sender();
     d++;
   }
   return vf;
 }
 //
 // utilities: JNI objects
 //
 jclass
 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
   assert(k != NULL, "k != NULL");
   return (jclass)jni_reference(k->java_mirror());
 }
 //
 // Field Information
 //
 bool
 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
   if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
     return false;
   }
   bool found = false;
   if (jfieldIDWorkaround::is_static_jfieldID(field)) {
     JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
     found = id->find_local_field(fd);
   } else {
     // Non-static field. The fieldID is really the offset of the field within the object.
     int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
     found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
   }
   return found;
 }
 //
 // Object Monitor Information
 //
 //
 // Count the number of objects for a lightweight monitor. The hobj
 // parameter is object that owns the monitor so this routine will
 // count the number of times the same object was locked by frames
 // in java_thread.
 //
 jint
 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
   jint ret = 0;
   if (!java_thread->has_last_Java_frame()) {
     return ret;  // no Java frames so no monitors
   }
   ResourceMark rm;
   HandleMark   hm;
   RegisterMap  reg_map(java_thread);
   for(javaVFrame *jvf=java_thread->last_java_vframe(&reg_map); jvf != NULL;
                                                  jvf = jvf->java_sender()) {
     GrowableArray<MonitorInfo*>* mons = jvf->monitors();
     if (!mons->is_empty()) {
       for (int i = 0; i < mons->length(); i++) {
         MonitorInfo *mi = mons->at(i);
         if (mi->owner_is_scalar_replaced()) continue;
         // see if owner of the monitor is our object
         if (mi->owner() != NULL && mi->owner() == hobj()) {
           ret++;
         }
       }
     }
   }
   return ret;
 }
 jvmtiError
 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
 #ifdef ASSERT
   uint32_t debug_bits = 0;
 #endif
   assert((SafepointSynchronize::is_at_safepoint() ||
           is_thread_fully_suspended(java_thread, false, &debug_bits)),
          "at safepoint or target thread is suspended");
   oop obj = NULL;
   ObjectMonitor *mon = java_thread->current_waiting_monitor();
   if (mon == NULL) {
     // thread is not doing an Object.wait() call
     mon = java_thread->current_pending_monitor();
     if (mon != NULL) {
       // The thread is trying to enter() or raw_enter() an ObjectMonitor.
       obj = (oop)mon->object();
       // If obj == NULL, then ObjectMonitor is raw which doesn't count
       // as contended for this API
     }
     // implied else: no contended ObjectMonitor
   } else {
     // thread is doing an Object.wait() call
     obj = (oop)mon->object();
     assert(obj != NULL, "Object.wait() should have an object");
   }
   if (obj == NULL) {
     *monitor_ptr = NULL;
   } else {
     HandleMark hm;
     Handle     hobj(obj);
     *monitor_ptr = jni_reference(calling_thread, hobj);
   }
   return JVMTI_ERROR_NONE;
 }
 jvmtiError
 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
                                  GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
   jvmtiError err = JVMTI_ERROR_NONE;
 #ifdef ASSERT
   uint32_t debug_bits = 0;
 #endif
   assert((SafepointSynchronize::is_at_safepoint() ||
           is_thread_fully_suspended(java_thread, false, &debug_bits)),
          "at safepoint or target thread is suspended");
   if (java_thread->has_last_Java_frame()) {
     ResourceMark rm;
     HandleMark   hm;
     RegisterMap  reg_map(java_thread);
     int depth = 0;
     for (javaVFrame *jvf = java_thread->last_java_vframe(&reg_map); jvf != NULL;
          jvf = jvf->java_sender()) {
       if (depth++ < MaxJavaStackTraceDepth) {  // check for stack too deep
         // add locked objects for this frame into list
         err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
         if (err != JVMTI_ERROR_NONE) {
           return err;
         }
       }
     }
   }
   // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
   JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
   ObjectSynchronizer::monitors_iterate(&jmc);
   err = jmc.error();
   return err;
 }
 // Save JNI local handles for any objects that this frame owns.
 jvmtiError
 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
                                  javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) {
   jvmtiError err = JVMTI_ERROR_NONE;
   ResourceMark rm;
   GrowableArray<MonitorInfo*>* mons = jvf->monitors();
   if (mons->is_empty()) {
     return err;  // this javaVFrame holds no monitors
   }
   HandleMark hm;
   oop wait_obj = NULL;
   {
     // save object of current wait() call (if any) for later comparison
     ObjectMonitor *mon = java_thread->current_waiting_monitor();
     if (mon != NULL) {
       wait_obj = (oop)mon->object();
     }
   }
   oop pending_obj = NULL;
   {
     // save object of current enter() call (if any) for later comparison
     ObjectMonitor *mon = java_thread->current_pending_monitor();
     if (mon != NULL) {
       pending_obj = (oop)mon->object();
     }
   }
   for (int i = 0; i < mons->length(); i++) {
     MonitorInfo *mi = mons->at(i);
     if (mi->owner_is_scalar_replaced()) continue;
     oop obj = mi->owner();
     if (obj == NULL) {
       // this monitor doesn't have an owning object so skip it
       continue;
     }
     if (wait_obj == obj) {
       // the thread is waiting on this monitor so it isn't really owned
       continue;
     }
     if (pending_obj == obj) {
       // the thread is pending on this monitor so it isn't really owned
       continue;
     }
     if (owned_monitors_list->length() > 0) {
       // Our list has at least one object on it so we have to check
       // for recursive object locking
       bool found = false;
       for (int j = 0; j < owned_monitors_list->length(); j++) {
         jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
         oop check = JNIHandles::resolve(jobj);
         if (check == obj) {
           found = true;  // we found the object
           break;
         }
       }
       if (found) {
         // already have this object so don't include it
         continue;
       }
     }
     // add the owning object to our list
     jvmtiMonitorStackDepthInfo *jmsdi;
     err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
     if (err != JVMTI_ERROR_NONE) {
         return err;
     }
     Handle hobj(obj);
     jmsdi->monitor = jni_reference(calling_thread, hobj);
     jmsdi->stack_depth = stack_depth;
     owned_monitors_list->append(jmsdi);
   }
   return err;
 }
 jvmtiError
 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
                               jint start_depth, jint max_count,
                               jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
 #ifdef ASSERT
   uint32_t debug_bits = 0;
 #endif
   assert((SafepointSynchronize::is_at_safepoint() ||
           is_thread_fully_suspended(java_thread, false, &debug_bits)),
          "at safepoint or target thread is suspended");
   int count = 0;
   if (java_thread->has_last_Java_frame()) {
     RegisterMap reg_map(java_thread);
     Thread* current_thread = Thread::current();
     ResourceMark rm(current_thread);
     javaVFrame *jvf = java_thread->last_java_vframe(&reg_map);
     HandleMark hm(current_thread);
     if (start_depth != 0) {
       if (start_depth > 0) {
         for (int j = 0; j < start_depth && jvf != NULL; j++) {
           jvf = jvf->java_sender();
         }
         if (jvf == NULL) {
           // start_depth is deeper than the stack depth
           return JVMTI_ERROR_ILLEGAL_ARGUMENT;
         }
       } else { // start_depth < 0
         // we are referencing the starting depth based on the oldest
         // part of the stack.
         // optimize to limit the number of times that java_sender() is called
         javaVFrame *jvf_cursor = jvf;
         javaVFrame *jvf_prev = NULL;
         javaVFrame *jvf_prev_prev;
         int j = 0;
         while (jvf_cursor != NULL) {
           jvf_prev_prev = jvf_prev;
           jvf_prev = jvf_cursor;
           for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
             jvf_cursor = jvf_cursor->java_sender();
           }
         }
         if (j == start_depth) {
           // previous pointer is exactly where we want to start
           jvf = jvf_prev;
         } else {
           // we need to back up further to get to the right place
           if (jvf_prev_prev == NULL) {
             // the -start_depth is greater than the stack depth
             return JVMTI_ERROR_ILLEGAL_ARGUMENT;
           }
           // j now is the number of frames on the stack starting with
           // jvf_prev, we start from jvf_prev_prev and move older on
           // the stack that many, the result is -start_depth frames
           // remaining.
           jvf = jvf_prev_prev;
           for (; j < 0; j++) {
             jvf = jvf->java_sender();
           }
         }
       }
     }
     for (; count < max_count && jvf != NULL; count++) {
       frame_buffer[count].method = jvf->method()->jmethod_id();
       frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
       jvf = jvf->java_sender();
     }
   } else {
     if (start_depth != 0) {
       // no frames and there is a starting depth
       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
     }
   }
   *count_ptr = count;
   return JVMTI_ERROR_NONE;
 }
 jvmtiError
 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
   assert((state != NULL),
          "JavaThread should create JvmtiThreadState before calling this method");
   *count_ptr = state->count_frames();
   return JVMTI_ERROR_NONE;
 }
 jvmtiError
 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
                                  jmethodID* method_ptr, jlocation* location_ptr) {
 #ifdef ASSERT
   uint32_t debug_bits = 0;
 #endif
   assert((SafepointSynchronize::is_at_safepoint() ||
           is_thread_fully_suspended(java_thread, false, &debug_bits)),
          "at safepoint or target thread is suspended");
   Thread* current_thread = Thread::current();
   ResourceMark rm(current_thread);
   vframe *vf = vframeFor(java_thread, depth);
   if (vf == NULL) {
     return JVMTI_ERROR_NO_MORE_FRAMES;
   }
   // vframeFor should return a java frame. If it doesn't
   // it means we've got an internal error and we return the
   // error in product mode. In debug mode we will instead
   // attempt to cast the vframe to a javaVFrame and will
   // cause an assertion/crash to allow further diagnosis.
 #ifdef PRODUCT
   if (!vf->is_java_frame()) {
     return JVMTI_ERROR_INTERNAL;
   }
 #endif
   HandleMark hm(current_thread);
   javaVFrame *jvf = javaVFrame::cast(vf);
   Method* method = jvf->method();
   if (method->is_native()) {
     *location_ptr = -1;
   } else {
     *location_ptr = jvf->bci();
   }
   *method_ptr = method->jmethod_id();
   return JVMTI_ERROR_NONE;
 }
 jvmtiError
 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
   HandleMark hm;
   Handle hobj;
   bool at_safepoint = SafepointSynchronize::is_at_safepoint();
   // Check arguments
   {
     oop mirror = JNIHandles::resolve_external_guard(object);
     NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
     NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
     hobj = Handle(mirror);
   }
   JavaThread *owning_thread = NULL;
   ObjectMonitor *mon = NULL;
   jvmtiMonitorUsage ret = {
       NULL, 0, 0, NULL, 0, NULL
   };
   uint32_t debug_bits = 0;
   // first derive the object's owner and entry_count (if any)
   {
     // Revoke any biases before querying the mark word
     if (SafepointSynchronize::is_at_safepoint()) {
       BiasedLocking::revoke_at_safepoint(hobj);
     } else {
       BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
     }
     address owner = NULL;
     {
       markOop mark = hobj()->mark();
       if (!mark->has_monitor()) {
         // this object has a lightweight monitor
         if (mark->has_locker()) {
           owner = (address)mark->locker(); // save the address of the Lock word
         }
         // implied else: no owner
       } else {
         // this object has a heavyweight monitor
         mon = mark->monitor();
         // The owner field of a heavyweight monitor may be NULL for no
         // owner, a JavaThread * or it may still be the address of the
         // Lock word in a JavaThread's stack. A monitor can be inflated
         // by a non-owning JavaThread, but only the owning JavaThread
         // can change the owner field from the Lock word to the
         // JavaThread * and it may not have done that yet.
         owner = (address)mon->owner();
       }
     }
     if (owner != NULL) {
       // This monitor is owned so we have to find the owning JavaThread.
       // Since owning_thread_from_monitor_owner() grabs a lock, GC can
       // move our object at this point. However, our owner value is safe
       // since it is either the Lock word on a stack or a JavaThread *.
       owning_thread = Threads::owning_thread_from_monitor_owner(owner, !at_safepoint);
       // Cannot assume (owning_thread != NULL) here because this function
       // may not have been called at a safepoint and the owning_thread
       // might not be suspended.
       if (owning_thread != NULL) {
         // The monitor's owner either has to be the current thread, at safepoint
         // or it has to be suspended. Any of these conditions will prevent both
         // contending and waiting threads from modifying the state of
         // the monitor.
         if (!at_safepoint && !JvmtiEnv::is_thread_fully_suspended(owning_thread, true, &debug_bits)) {
           // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
           // will not make it back to the JVM/TI agent. The error code will
           // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
           // will retry the call via a VM_GetObjectMonitorUsage VM op.
           return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
         }
         HandleMark hm;
         Handle     th(owning_thread->threadObj());
         ret.owner = (jthread)jni_reference(calling_thread, th);
       }
       // implied else: no owner
     }
     if (owning_thread != NULL) {  // monitor is owned
       if ((address)owning_thread == owner) {
         // the owner field is the JavaThread *
         assert(mon != NULL,
           "must have heavyweight monitor with JavaThread * owner");
         ret.entry_count = mon->recursions() + 1;
       } else {
         // The owner field is the Lock word on the JavaThread's stack
         // so the recursions field is not valid. We have to count the
         // number of recursive monitor entries the hard way. We pass
         // a handle to survive any GCs along the way.
         ResourceMark rm;
         ret.entry_count = count_locked_objects(owning_thread, hobj);
       }
     }
     // implied else: entry_count == 0
   }
   int nWant,nWait;
   if (mon != NULL) {
     // this object has a heavyweight monitor
     nWant = mon->contentions(); // # of threads contending for monitor
     nWait = mon->waiters();     // # of threads in Object.wait()
     ret.waiter_count = nWant + nWait;
     ret.notify_waiter_count = nWait;
   } else {
     // this object has a lightweight monitor
     ret.waiter_count = 0;
     ret.notify_waiter_count = 0;
   }
   // Allocate memory for heavyweight and lightweight monitor.
   jvmtiError err;
   err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
   if (err != JVMTI_ERROR_NONE) {
     return err;
   }
   err = allocate(ret.notify_waiter_count * sizeof(jthread *),
                  (unsigned char**)&ret.notify_waiters);
   if (err != JVMTI_ERROR_NONE) {
     deallocate((unsigned char*)ret.waiters);
     return err;
   }
   // now derive the rest of the fields
   if (mon != NULL) {
     // this object has a heavyweight monitor
     // Number of waiters may actually be less than the waiter count.
     // So NULL out memory so that unused memory will be NULL.
     memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
     memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
     if (ret.waiter_count > 0) {
       // we have contending and/or waiting threads
       HandleMark hm;
       if (nWant > 0) {
         // we have contending threads
         ResourceMark rm;
         // get_pending_threads returns only java thread so we do not need to
         // check for  non java threads.
         GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(
           nWant, (address)mon, !at_safepoint);
         if (wantList->length() < nWant) {
           // robustness: the pending list has gotten smaller
           nWant = wantList->length();
         }
         for (int i = 0; i < nWant; i++) {
           JavaThread *pending_thread = wantList->at(i);
           // If the monitor has no owner, then a non-suspended contending
           // thread could potentially change the state of the monitor by
           // entering it. The JVM/TI spec doesn't allow this.
           if (owning_thread == NULL && !at_safepoint &
               !JvmtiEnv::is_thread_fully_suspended(pending_thread, true, &debug_bits)) {
             if (ret.owner != NULL) {
               destroy_jni_reference(calling_thread, ret.owner);
             }
             for (int j = 0; j < i; j++) {
               destroy_jni_reference(calling_thread, ret.waiters[j]);
             }
             deallocate((unsigned char*)ret.waiters);
             deallocate((unsigned char*)ret.notify_waiters);
             return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
           }
           Handle th(pending_thread->threadObj());
           ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
         }
       }
       if (nWait > 0) {
         // we have threads in Object.wait()
         int offset = nWant;  // add after any contending threads
         ObjectWaiter *waiter = mon->first_waiter();
         for (int i = 0, j = 0; i < nWait; i++) {
           if (waiter == NULL) {
             // robustness: the waiting list has gotten smaller
             nWait = j;
             break;
           }
           Thread *t = mon->thread_of_waiter(waiter);
           if (t != NULL && t->is_Java_thread()) {
             JavaThread *wjava_thread = (JavaThread *)t;
             // If the thread was found on the ObjectWaiter list, then
             // it has not been notified. This thread can't change the
             // state of the monitor so it doesn't need to be suspended.
             Handle th(wjava_thread->threadObj());
             ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
             ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
           }
           waiter = mon->next_waiter(waiter);
         }
       }
     }
     // Adjust count. nWant and nWait count values may be less than original.
     ret.waiter_count = nWant + nWait;
     ret.notify_waiter_count = nWait;
   } else {
     // this object has a lightweight monitor and we have nothing more
     // to do here because the defaults are just fine.
   }
   // we don't update return parameter unless everything worked
   *info_ptr = ret;
   return JVMTI_ERROR_NONE;
 }
 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
   _env = env;
   _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true);
   _failed = false;
 }
 ResourceTracker::~ResourceTracker() {
   if (_failed) {
     for (int i=0; i<_allocations->length(); i++) {
       _env->deallocate(_allocations->at(i));
     }
   }
   delete _allocations;
 }
 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
   unsigned char *ptr;
   jvmtiError err = _env->allocate(size, &ptr);
   if (err == JVMTI_ERROR_NONE) {
     _allocations->append(ptr);
     *mem_ptr = ptr;
   } else {
     *mem_ptr = NULL;
     _failed = true;
   }
   return err;
  }
 unsigned char* ResourceTracker::allocate(jlong size) {
   unsigned char* ptr;
   allocate(size, &ptr);
   return ptr;
 }
 char* ResourceTracker::strdup(const char* str) {
   char *dup_str = (char*)allocate(strlen(str)+1);
   if (dup_str != NULL) {
     strcpy(dup_str, str);
   }
   return dup_str;
 }
 struct StackInfoNode {
   struct StackInfoNode *next;
   jvmtiStackInfo info;
 };
 // Create a jvmtiStackInfo inside a linked list node and create a
 // buffer for the frame information, both allocated as resource objects.
 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
 // Note that either or both of thr and thread_oop
 // may be null if the thread is new or has exited.
 void
 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   jint state = 0;
   struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
   jvmtiStackInfo *infop = &(node->info);
   node->next = head();
   set_head(node);
   infop->frame_count = 0;
   infop->thread = jt;
   if (thread_oop != NULL) {
     // get most state bits
     state = (jint)java_lang_Thread::get_thread_status(thread_oop);
   }
   if (thr != NULL) {    // add more state bits if there is a JavaThead to query
     // same as is_being_ext_suspended() but without locking
     if (thr->is_ext_suspended() || thr->is_external_suspend()) {
       state |= JVMTI_THREAD_STATE_SUSPENDED;
     }
     JavaThreadState jts = thr->thread_state();
     if (jts == _thread_in_native) {
       state |= JVMTI_THREAD_STATE_IN_NATIVE;
     }
     OSThread* osThread = thr->osthread();
     if (osThread != NULL && osThread->interrupted()) {
       state |= JVMTI_THREAD_STATE_INTERRUPTED;
     }
   }
   infop->state = state;
   if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
     infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
     env()->get_stack_trace(thr, 0, max_frame_count(),
                            infop->frame_buffer, &(infop->frame_count));
   } else {
     infop->frame_buffer = NULL;
     infop->frame_count = 0;
   }
   _frame_count_total += infop->frame_count;
 }
 // Based on the stack information in the linked list, allocate memory
 // block to return and fill it from the info in the linked list.
 void
 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
   // do I need to worry about alignment issues?
   jlong alloc_size =  thread_count       * sizeof(jvmtiStackInfo)
                     + _frame_count_total * sizeof(jvmtiFrameInfo);
   env()->allocate(alloc_size, (unsigned char **)&_stack_info);
   // pointers to move through the newly allocated space as it is filled in
   jvmtiStackInfo *si = _stack_info + thread_count;      // bottom of stack info
   jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si;            // is the top of frame info
   // copy information in resource area into allocated buffer
   // insert stack info backwards since linked list is backwards
   // insert frame info forwards
   // walk the StackInfoNodes
   for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
     jint frame_count = sin->info.frame_count;
     size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
     --si;
     memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
     if (frames_size == 0) {
       si->frame_buffer = NULL;
     } else {
       memcpy(fi, sin->info.frame_buffer, frames_size);
       si->frame_buffer = fi;  // point to the new allocated copy of the frames
       fi += frame_count;
     }
   }
   assert(si == _stack_info, "the last copied stack info must be the first record");
   assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
          "the last copied frame info must be the last record");
 }
 void
 VM_GetThreadListStackTraces::doit() {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   ResourceMark rm;
   for (int i = 0; i < _thread_count; ++i) {
     jthread jt = _thread_list[i];
     oop thread_oop = JNIHandles::resolve_external_guard(jt);
     if (thread_oop == NULL || !thread_oop->is_a(SystemDictionary::Thread_klass())) {
       set_result(JVMTI_ERROR_INVALID_THREAD);
       return;
     }
     fill_frames(jt, java_lang_Thread::thread(thread_oop), thread_oop);
   }
   allocate_and_fill_stacks(_thread_count);
 }
 void
 VM_GetAllStackTraces::doit() {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   ResourceMark rm;
   _final_thread_count = 0;
   for (JavaThread *jt = Threads::first(); jt != NULL; jt = jt->next()) {
     oop thread_oop = jt->threadObj();
     if (thread_oop != NULL &&
         !jt->is_exiting() &&
         java_lang_Thread::is_alive(thread_oop) &&
         !jt->is_hidden_from_external_view()) {
       ++_final_thread_count;
       // Handle block of the calling thread is used to create local refs.
       fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
                   jt, thread_oop);
     }
   }
   allocate_and_fill_stacks(_final_thread_count);
 }
 // Verifies that the top frame is a java frame in an expected state.
 // Deoptimizes frame if needed.
 // Checks that the frame method signature matches the return type (tos).
 // HandleMark must be defined in the caller only.
 // It is to keep a ret_ob_h handle alive after return to the caller.
 jvmtiError
 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
                               jvalue value, TosState tos, Handle* ret_ob_h) {
   ResourceMark rm(current_thread);
   vframe *vf = vframeFor(java_thread, 0);
   NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
   javaVFrame *jvf = (javaVFrame*) vf;
   if (!vf->is_java_frame() || jvf->method()->is_native()) {
     return JVMTI_ERROR_OPAQUE_FRAME;
   }
   // If the frame is a compiled one, need to deoptimize it.
   if (vf->is_compiled_frame()) {
     if (!vf->fr().can_be_deoptimized()) {
       return JVMTI_ERROR_OPAQUE_FRAME;
     }
     Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
   }
   // Get information about method return type
   Symbol* signature = jvf->method()->signature();
   ResultTypeFinder rtf(signature);
   TosState fr_tos = as_TosState(rtf.type());
   if (fr_tos != tos) {
     if (tos != itos || (fr_tos != btos && fr_tos != ctos && fr_tos != stos)) {
       return JVMTI_ERROR_TYPE_MISMATCH;
     }
   }
   // Check that the jobject class matches the return type signature.
   jobject jobj = value.l;
   if (tos == atos && jobj != NULL) { // NULL reference is allowed
     Handle ob_h = Handle(current_thread, JNIHandles::resolve_external_guard(jobj));
     NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
     KlassHandle ob_kh = KlassHandle(current_thread, ob_h()->klass());
     NULL_CHECK(ob_kh, JVMTI_ERROR_INVALID_OBJECT);
     // Method return type signature.
     char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
     if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_kh(), current_thread)) {
       return JVMTI_ERROR_TYPE_MISMATCH;
     }
     *ret_ob_h = ob_h;
   }
   return JVMTI_ERROR_NONE;
 } /* end check_top_frame */
 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
 // Main difference is on the last stage in the interpreter.
 // The PopFrame stops method execution to continue execution
 // from the same method call instruction.
 // The ForceEarlyReturn forces return from method so the execution
 // continues at the bytecode following the method call.
 // Threads_lock NOT held, java_thread not protected by lock
 // java_thread - pre-checked
 jvmtiError
 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
   JavaThread* current_thread = JavaThread::current();
   HandleMark   hm(current_thread);
   uint32_t debug_bits = 0;
   // retrieve or create the state
   JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
   if (state == NULL) {
     return JVMTI_ERROR_THREAD_NOT_ALIVE;
   }
   // Check if java_thread is fully suspended
   if (!is_thread_fully_suspended(java_thread,
                                  true /* wait for suspend completion */,
                                  &debug_bits)) {
     return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
   }
   // Check to see if a ForceEarlyReturn was already in progress
   if (state->is_earlyret_pending()) {
     // Probably possible for JVMTI clients to trigger this, but the
     // JPDA backend shouldn't allow this to happen
     return JVMTI_ERROR_INTERNAL;
   }
   {
     // The same as for PopFrame. Workaround bug:
     //  4812902: popFrame hangs if the method is waiting at a synchronize
     // Catch this condition and return an error to avoid hanging.
     // Now JVMTI spec allows an implementation to bail out with an opaque
     // frame error.
     OSThread* osThread = java_thread->osthread();
     if (osThread->get_state() == MONITOR_WAIT) {
       return JVMTI_ERROR_OPAQUE_FRAME;
     }
   }
   Handle ret_ob_h = Handle();
   jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
   if (err != JVMTI_ERROR_NONE) {
     return err;
   }
   assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
          "return object oop must not be NULL if jobject is not NULL");
   // Update the thread state to reflect that the top frame must be
   // forced to return.
   // The current frame will be returned later when the suspended
   // thread is resumed and right before returning from VM to Java.
   // (see call_VM_base() in assembler_<cpu>.cpp).
   state->set_earlyret_pending();
   state->set_earlyret_oop(ret_ob_h());
   state->set_earlyret_value(value, tos);
   // Set pending step flag for this early return.
   // It is cleared when next step event is posted.
   state->set_pending_step_for_earlyret();
   return JVMTI_ERROR_NONE;
 } /* end force_early_return */
 void
 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
   if ( _error != JVMTI_ERROR_NONE) {
     // Error occurred in previous iteration so no need to add
     // to the list.
     return;
   }
   if (mon->owner() == _java_thread ) {
     // Filter out on stack monitors collected during stack walk.
     oop obj = (oop)mon->object();
     bool found = false;
     for (int j = 0; j < _owned_monitors_list->length(); j++) {
       jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
       oop check = JNIHandles::resolve(jobj);
       if (check == obj) {
         // On stack monitor already collected during the stack walk.
         found = true;
         break;
       }
     }
     if (found == false) {
       // This is off stack monitor (e.g. acquired via jni MonitorEnter).
       jvmtiError err;
       jvmtiMonitorStackDepthInfo *jmsdi;
       err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
       if (err != JVMTI_ERROR_NONE) {
         _error = err;
         return;
       }
       Handle hobj(obj);
       jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
       // stack depth is unknown for this monitor.
       jmsdi->stack_depth = -1;
       _owned_monitors_list->append(jmsdi);
     }
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/prims/jvmtiEnvBase.cpp@04ff2f6cd0eb (annotated)

src/share/vm/prims/jvmtiEnvBase.cpp