hotspot/src/share/vm/prims/jvmtiGetLoadedClasses.cpp - edge/openjdk - Git at Google

 /*
  * 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 "memory/universe.inline.hpp"
 #include "prims/jvmtiGetLoadedClasses.hpp"
 #include "runtime/thread.hpp"


 // The closure for GetLoadedClasses
 class LoadedClassesClosure : public KlassClosure {
 private:
   Stack<jclass, mtInternal> _classStack;
   JvmtiEnv* _env;

 public:
   LoadedClassesClosure(JvmtiEnv* env) {
     _env = env;
   }

   void do_klass(Klass* k) {
     // Collect all jclasses
     _classStack.push((jclass) _env->jni_reference(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;
 }
	/*
	* 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 "memory/universe.inline.hpp"
	#include "prims/jvmtiGetLoadedClasses.hpp"
	#include "runtime/thread.hpp"


	// The closure for GetLoadedClasses
	class LoadedClassesClosure : public KlassClosure {
	private:
	Stack<jclass, mtInternal> _classStack;
	JvmtiEnv* _env;

	public:
	LoadedClassesClosure(JvmtiEnv* env) {
	_env = env;
	}

	void do_klass(Klass* k) {
	// Collect all jclasses
	_classStack.push((jclass) _env->jni_reference(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;
	}