jdk8-mips64-public/hotspot: src/share/vm/prims/jvmtiGetLoadedClasses.cpp@eef07cd490d4 (annotated)

src/share/vm/prims/jvmtiGetLoadedClasses.cpp@eef07cd490d4 (annotated)

src/share/vm/prims/jvmtiGetLoadedClasses.cpp

Wed, 03 Jul 2019 20:42:37 +0800

author: aoqi
date: Wed, 03 Jul 2019 20:42:37 +0800
changeset 9637: eef07cd490d4
parent 9203: 53eec13fbaa5
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2003, 2018, 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 "memory/universe.inline.hpp"
 #include "prims/jvmtiGetLoadedClasses.hpp"
 #include "runtime/thread.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
 #endif
 // The closure for GetLoadedClasses
 class LoadedClassesClosure : public KlassClosure {
 private:
   Stack<jclass, mtInternal> _classStack;
   JvmtiEnv* _env;
 // Tell the GC to keep this klass alive
 static void ensure_klass_alive(oop o) {
   // A klass that was previously considered dead can be looked up in the
   // CLD/SD, and its _java_mirror or _class_loader can be stored in a root
   // or a reachable object making it alive again. The SATB part of G1 needs
   // to get notified about this potential resurrection, otherwise the marking
   // might not find the object.
 #if INCLUDE_ALL_GCS
   if (UseG1GC && o != NULL) {
     G1SATBCardTableModRefBS::enqueue(o);
   }
 #endif
 }
 public:
   LoadedClassesClosure(JvmtiEnv* env) {
     _env = env;
   }
   void do_klass(Klass* k) {
     // Collect all jclasses
     _classStack.push((jclass) _env->jni_reference(k->java_mirror()));
     ensure_klass_alive(k->java_mirror());
   }
   int extract(jclass* result_list) {
     // The size of the Stack will be 0 after extract, so get it here
     int count = (int)_classStack.size();
     int i = count;
     // Pop all jclasses, fill backwards
     while (!_classStack.is_empty()) {
       result_list[--i] = _classStack.pop();
     }
     // Return the number of elements written
     return count;
   }
   // Return current size of the Stack
   int get_count() {
     return (int)_classStack.size();
   }
 };
 // The closure for GetClassLoaderClasses
 class JvmtiGetLoadedClassesClosure : public StackObj {
   // Since the SystemDictionary::classes_do callback
   // doesn't pass a closureData pointer,
   // we use a thread-local slot to hold a pointer to
   // a stack allocated instance of this structure.
  private:
   jobject _initiatingLoader;
   int     _count;
   Handle* _list;
   int     _index;
  private:
   // Getting and setting the thread local pointer
   static JvmtiGetLoadedClassesClosure* get_this() {
     JvmtiGetLoadedClassesClosure* result = NULL;
     JavaThread* thread = JavaThread::current();
     result = thread->get_jvmti_get_loaded_classes_closure();
     return result;
   }
   static void set_this(JvmtiGetLoadedClassesClosure* that) {
     JavaThread* thread = JavaThread::current();
     thread->set_jvmti_get_loaded_classes_closure(that);
   }
  public:
   // Constructor/Destructor
   JvmtiGetLoadedClassesClosure() {
     JvmtiGetLoadedClassesClosure* that = get_this();
     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
     _initiatingLoader = NULL;
     _count = 0;
     _list = NULL;
     _index = 0;
     set_this(this);
   }
   JvmtiGetLoadedClassesClosure(jobject initiatingLoader) {
     JvmtiGetLoadedClassesClosure* that = get_this();
     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
     _initiatingLoader = initiatingLoader;
     _count = 0;
     _list = NULL;
     _index = 0;
     set_this(this);
   }
   ~JvmtiGetLoadedClassesClosure() {
     JvmtiGetLoadedClassesClosure* that = get_this();
     assert(that != NULL, "JvmtiGetLoadedClassesClosure not found");
     set_this(NULL);
     _initiatingLoader = NULL;
     _count = 0;
     if (_list != NULL) {
       FreeHeap(_list);
       _list = NULL;
     }
     _index = 0;
   }
   // Accessors.
   jobject get_initiatingLoader() {
     return _initiatingLoader;
   }
   int get_count() {
     return _count;
   }
   void set_count(int value) {
     _count = value;
   }
   Handle* get_list() {
     return _list;
   }
   void set_list(Handle* value) {
     _list = value;
   }
   int get_index() {
     return _index;
   }
   void set_index(int value) {
     _index = value;
   }
   Handle get_element(int index) {
     if ((_list != NULL) && (index < _count)) {
       return _list[index];
     } else {
       assert(false, "empty get_element");
       return Handle();
     }
   }
   void set_element(int index, Handle value) {
     if ((_list != NULL) && (index < _count)) {
       _list[index] = value;
     } else {
       assert(false, "bad set_element");
     }
   }
   // Other predicates
   bool available() {
     return (_list != NULL);
   }
 #ifdef ASSERT
   // For debugging.
   void check(int limit) {
     for (int i = 0; i < limit; i += 1) {
       assert(Universe::heap()->is_in(get_element(i)()), "check fails");
     }
   }
 #endif
   // Public methods that get called within the scope of the closure
   void allocate() {
     _list = NEW_C_HEAP_ARRAY(Handle, _count, mtInternal);
     assert(_list != NULL, "Out of memory");
     if (_list == NULL) {
       _count = 0;
     }
   }
   void extract(JvmtiEnv *env, jclass* result) {
     for (int index = 0; index < _count; index += 1) {
       result[index] = (jclass) env->jni_reference(get_element(index));
     }
   }
   static void increment_with_loader(Klass* k, ClassLoaderData* loader_data) {
     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
     oop class_loader = loader_data->class_loader();
     if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
       for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
         that->set_count(that->get_count() + 1);
       }
     }
   }
   static void prim_array_increment_with_loader(Klass* array, ClassLoaderData* loader_data) {
     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
     oop class_loader = loader_data->class_loader();
     if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
       that->set_count(that->get_count() + 1);
     }
   }
   static void add_with_loader(Klass* k, ClassLoaderData* loader_data) {
     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
     if (that->available()) {
       oop class_loader = loader_data->class_loader();
       if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
         for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
           oop mirror = l->java_mirror();
           that->set_element(that->get_index(), mirror);
           that->set_index(that->get_index() + 1);
         }
       }
     }
   }
   // increment the count for the given basic type array class (and any
   // multi-dimensional arrays). For example, for [B we check for
   // [[B, [[[B, .. and the count is incremented for each one that exists.
   static void increment_for_basic_type_arrays(Klass* k) {
     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
       that->set_count(that->get_count() + 1);
     }
   }
   // add the basic type array class and its multi-dimensional array classes to the list
   static void add_for_basic_type_arrays(Klass* k) {
     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
     assert(that->available(), "no list");
     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
       oop mirror = l->java_mirror();
       that->set_element(that->get_index(), mirror);
       that->set_index(that->get_index() + 1);
     }
   }
 };
 jvmtiError
 JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
   LoadedClassesClosure closure(env);
   {
     // To get a consistent list of classes we need MultiArray_lock to ensure
     // array classes aren't created.
     MutexLocker ma(MultiArray_lock);
     // Iterate through all classes in ClassLoaderDataGraph
     // and collect them using the LoadedClassesClosure
     ClassLoaderDataGraph::loaded_classes_do(&closure);
   }
   // Return results by extracting the collected contents into a list
   // allocated via JvmtiEnv
   jclass* result_list;
   jvmtiError error = env->Allocate(closure.get_count() * sizeof(jclass),
                                (unsigned char**)&result_list);
   if (error == JVMTI_ERROR_NONE) {
     int count = closure.extract(result_list);
     *classCountPtr = count;
     *classesPtr = result_list;
   }
   return error;
 }
 jvmtiError
 JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader,
                                              jint* classCountPtr, jclass** classesPtr) {
   // Since SystemDictionary::classes_do only takes a function pointer
   // and doesn't call back with a closure data pointer,
   // we can only pass static methods.
   JvmtiGetLoadedClassesClosure closure(initiatingLoader);
   {
     // To get a consistent list of classes we need MultiArray_lock to ensure
     // array classes aren't created, and SystemDictionary_lock to ensure that
     // classes aren't added to the system dictionary,
     MutexLocker ma(MultiArray_lock);
     MutexLocker sd(SystemDictionary_lock);
     // First, count the classes in the system dictionary which have this loader recorded
     // as an initiating loader. For basic type arrays this information is not recorded
     // so GetClassLoaderClasses will return all of the basic type arrays. This is okay
     // because the defining loader for basic type arrays is always the boot class loader
     // and these classes are "visible" to all loaders.
     SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);
     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);
     // Next, fill in the classes
     closure.allocate();
     SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::add_with_loader);
     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays);
     // Drop the SystemDictionary_lock, so the results could be wrong from here,
     // but we still have a snapshot.
   }
   // Post results
   jclass* result_list;
   jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass),
                                  (unsigned char**)&result_list);
   if (err != JVMTI_ERROR_NONE) {
     return err;
   }
   closure.extract(env, result_list);
   *classCountPtr = closure.get_count();
   *classesPtr = result_list;
   return JVMTI_ERROR_NONE;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/prims/jvmtiGetLoadedClasses.cpp@eef07cd490d4 (annotated)

src/share/vm/prims/jvmtiGetLoadedClasses.cpp