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src/hotspot/share/prims/jvmtiGetLoadedClasses.cpp
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@@ -21,10 +21,11 @@
* questions.
*
*/
#include "precompiled.hpp"
+#include "classfile/dictionary.hpp"
#include "classfile/classLoaderData.inline.hpp"
#include "classfile/systemDictionary.hpp"
#include "gc/shared/collectedHeap.hpp"
#include "memory/universe.hpp"
#include "prims/jvmtiGetLoadedClasses.hpp"
@@ -37,20 +38,11 @@
class LoadedClassesClosure : public KlassClosure {
private:
Stack<jclass, mtInternal> _classStack;
JvmtiEnv* _env;
Thread* _cur_thread;
-
-public:
- LoadedClassesClosure(Thread* thread, JvmtiEnv* env) : _env(env), _cur_thread(thread) {
- assert(_cur_thread == Thread::current(), "must be current thread");
- }
-
- void do_klass(Klass* k) {
- // Collect all jclasses
- _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, k->java_mirror())));
- }
+ bool _dictionary_walk;
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;
@@ -66,260 +58,85 @@
// Return current size of the Stack
int get_count() {
return (int)_classStack.size();
}
-};
-
-// The closure for GetClassLoaderClasses
-class JvmtiGetLoadedClassesClosure : public StackObj {
- // Since the ClassLoaderDataGraph::dictionary_all_entries_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(InstanceKlass* 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);
- }
- }
+public:
+ LoadedClassesClosure(JvmtiEnv* env, bool dictionary_walk) :
+ _env(env),
+ _cur_thread(Thread::current()),
+ _dictionary_walk(dictionary_walk) {
}
- static void add_with_loader(InstanceKlass* 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())) {
- Thread *thread = Thread::current();
- for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
- Handle mirror(thread, l->java_mirror());
- that->set_element(that->get_index(), mirror);
- that->set_index(that->get_index() + 1);
- }
+ void do_klass(Klass* k) {
+ // Collect all jclasses
+ _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, k->java_mirror())));
+ if (_dictionary_walk) {
+ // Collect array classes this way when walking the dictionary (because array classes are
+ // not in the dictionary).
+ for (Klass* l = k->array_klass_or_null(); l != NULL; l = l->array_klass_or_null()) {
+ _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, l->java_mirror())));
}
}
}
- // 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);
- }
- }
+ jvmtiError get_result(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
+ // Return results by extracting the collected contents into a list
+ // allocated via JvmtiEnv
+ jclass* result_list;
+ jvmtiError error = env->Allocate(get_count() * sizeof(jclass),
+ (unsigned char**)&result_list);
- // 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");
- Thread *thread = Thread::current();
- for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
- Handle mirror(thread, l->java_mirror());
- that->set_element(that->get_index(), mirror);
- that->set_index(that->get_index() + 1);
+ if (error == JVMTI_ERROR_NONE) {
+ int count = extract(result_list);
+ *classCountPtr = count;
+ *classesPtr = result_list;
}
+ return error;
}
};
-
jvmtiError
JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
- LoadedClassesClosure closure(Thread::current(), env);
+ LoadedClassesClosure closure(env, false);
{
// 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;
+ return closure.get_result(env, classCountPtr, classesPtr);
}
jvmtiError
JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader,
jint* classCountPtr, jclass** classesPtr) {
- // Since ClassLoaderDataGraph::dictionary_all_entries_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);
+
+ LoadedClassesClosure closure(env, true);
{
// 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 class loader data dictionaries.
+ // array classes aren't created during this walk.
MutexLocker ma(MultiArray_lock);
MutexLocker sd(SystemDictionary_lock);
- // First, count the classes in the class loader data dictionaries 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.
- ClassLoaderDataGraph::dictionary_all_entries_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);
- Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);
- // Next, fill in the classes
- closure.allocate();
- ClassLoaderDataGraph::dictionary_all_entries_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.
+ oop loader = JNIHandles::resolve(initiatingLoader);
+ if (loader != NULL) {
+ ClassLoaderData* data = java_lang_ClassLoader::loader_data(loader);
+ // ClassLoader may not be used yet for loading.
+ if (data != NULL && data->dictionary() != NULL) {
+ data->dictionary()->all_entries_do(&closure);
}
- // 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;
+ // Get basic arrays for all loaders.
+ Universe::basic_type_classes_do(&closure);
+ } else {
+ ClassLoaderData::the_null_class_loader_data()->dictionary()->all_entries_do(&closure);
+ Universe::basic_type_classes_do(&closure);
}
- closure.extract(env, result_list);
- *classCountPtr = closure.get_count();
- *classesPtr = result_list;
- return JVMTI_ERROR_NONE;
+ }
+
+ return closure.get_result(env, classCountPtr, classesPtr);
}
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