1 /* 2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/javaClasses.inline.hpp" 27 #include "classfile/symbolTable.hpp" 28 #include "jfr/jni/jfrGetAllEventClasses.hpp" 29 #include "jfr/jni/jfrJavaSupport.hpp" 30 #include "jfr/recorder/access/jfrEventClass.hpp" 31 #include "oops/instanceKlass.hpp" 32 #include "memory/allocation.inline.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "runtime/handles.inline.hpp" 35 #include "runtime/mutexLocker.hpp" 36 #include "runtime/safepoint.hpp" 37 #include "runtime/thread.inline.hpp" 38 #include "utilities/growableArray.hpp" 39 #include "utilities/stack.inline.hpp" 40 41 // incremented during class unloading (safepoint) for each unloaded event class 42 static jlong unloaded_event_classes = 0; 43 44 jlong JfrEventClasses::unloaded_event_classes_count() { 45 return unloaded_event_classes; 46 } 47 48 void JfrEventClasses::increment_unloaded_event_class() { 49 // incremented during class unloading (safepoint) for each unloaded event class 50 assert(SafepointSynchronize::is_at_safepoint(), "invariant"); 51 ++unloaded_event_classes; 52 } 53 54 static jobject empty_java_util_arraylist = NULL; 55 56 static oop new_java_util_arraylist(TRAPS) { 57 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD)); 58 JavaValue result(T_OBJECT); 59 JfrJavaArguments args(&result, "java/util/ArrayList", "<init>", "()V", CHECK_NULL); 60 JfrJavaSupport::new_object(&args, CHECK_NULL); 61 return (oop)result.get_jobject(); 62 } 63 64 static bool initialize(TRAPS) { 65 static bool initialized = false; 66 if (!initialized) { 67 unloaded_event_classes = 0; 68 assert(NULL == empty_java_util_arraylist, "invariant"); 69 const oop array_list = new_java_util_arraylist(CHECK_false); 70 empty_java_util_arraylist = JfrJavaSupport::global_jni_handle(array_list, THREAD); 71 initialized = empty_java_util_arraylist != NULL; 72 } 73 return initialized; 74 } 75 76 /* 77 * Abstract klasses are filtered out unconditionally. 78 * If a klass is not yet initialized, i.e yet to run its <clinit> 79 * it is also filtered out so we don't accidentally 80 * trigger initialization. 81 */ 82 static bool is_whitelisted(const Klass* k) { 83 assert(k != NULL, "invariant"); 84 return !(k->is_abstract() || k->should_be_initialized()); 85 } 86 87 static void fill_klasses(GrowableArray<const void*>& event_subklasses, const Klass* event_klass, Thread* thread) { 88 assert(event_subklasses.length() == 0, "invariant"); 89 assert(event_klass != NULL, "invariant"); 90 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread)); 91 92 Stack<const Klass*, mtTracing> mark_stack; 93 MutexLocker ml(Compile_lock, thread); 94 mark_stack.push(event_klass->subklass()); 95 96 while (!mark_stack.is_empty()) { 97 const Klass* const current = mark_stack.pop(); 98 assert(current != NULL, "null element in stack!"); 99 100 if (is_whitelisted(current)) { 101 event_subklasses.append(current); 102 } 103 104 // subclass (depth) 105 const Klass* next_klass = current->subklass(); 106 if (next_klass != NULL) { 107 mark_stack.push(next_klass); 108 } 109 110 // siblings (breadth) 111 next_klass = current->next_sibling(); 112 if (next_klass != NULL) { 113 mark_stack.push(next_klass); 114 } 115 } 116 assert(mark_stack.is_empty(), "invariant"); 117 } 118 119 static void transform_klasses_to_local_jni_handles(GrowableArray<const void*>& event_subklasses, Thread* thread) { 120 assert(event_subklasses.is_nonempty(), "invariant"); 121 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread)); 122 123 for (int i = 0; i < event_subklasses.length(); ++i) { 124 const InstanceKlass* k = static_cast<const InstanceKlass*>(event_subklasses.at(i)); 125 assert(is_whitelisted(k), "invariant"); 126 event_subklasses.at_put(i, JfrJavaSupport::local_jni_handle(k->java_mirror(), thread)); 127 } 128 } 129 130 static const int initial_size_growable_array = 64; 131 132 jobject JfrEventClasses::get_all_event_classes(TRAPS) { 133 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD)); 134 initialize(THREAD); 135 assert(empty_java_util_arraylist != NULL, "should have been setup already!"); 136 static const char jdk_jfr_event_name[] = "jdk/jfr/Event"; 137 unsigned int unused_hash = 0; 138 Symbol* const event_klass_name = SymbolTable::lookup_only(jdk_jfr_event_name, sizeof jdk_jfr_event_name - 1, unused_hash); 139 140 if (NULL == event_klass_name) { 141 // not loaded yet 142 return empty_java_util_arraylist; 143 } 144 145 const Klass* const klass = SystemDictionary::resolve_or_null(event_klass_name, THREAD); 146 assert(klass != NULL, "invariant"); 147 assert(JdkJfrEvent::is(klass), "invariant"); 148 149 if (klass->subklass() == NULL) { 150 return empty_java_util_arraylist; 151 } 152 153 ResourceMark rm(THREAD); 154 GrowableArray<const void*> event_subklasses(THREAD, initial_size_growable_array); 155 fill_klasses(event_subklasses, klass, THREAD); 156 157 if (event_subklasses.is_empty()) { 158 return empty_java_util_arraylist; 159 } 160 161 transform_klasses_to_local_jni_handles(event_subklasses, THREAD); 162 163 Handle h_array_list(THREAD, new_java_util_arraylist(THREAD)); 164 assert(h_array_list.not_null(), "invariant"); 165 166 static const char add_method_name[] = "add"; 167 static const char add_method_signature[] = "(Ljava/lang/Object;)Z"; 168 const Klass* const array_list_klass = JfrJavaSupport::klass(empty_java_util_arraylist); 169 assert(array_list_klass != NULL, "invariant"); 170 171 const Symbol* const add_method_sym = SymbolTable::lookup(add_method_name, sizeof add_method_name - 1, THREAD); 172 assert(add_method_sym != NULL, "invariant"); 173 174 const Symbol* const add_method_sig_sym = SymbolTable::lookup(add_method_signature, sizeof add_method_signature - 1, THREAD); 175 assert(add_method_signature != NULL, "invariant"); 176 177 JavaValue result(T_BOOLEAN); 178 for (int i = 0; i < event_subklasses.length(); ++i) { 179 const jclass clazz = (const jclass)event_subklasses.at(i); 180 assert(JdkJfrEvent::is_subklass(clazz), "invariant"); 181 JfrJavaArguments args(&result, array_list_klass, add_method_sym, add_method_sig_sym); 182 args.set_receiver(h_array_list()); 183 args.push_jobject(clazz); 184 JfrJavaSupport::call_virtual(&args, THREAD); 185 if (HAS_PENDING_EXCEPTION || JNI_FALSE == result.get_jboolean()) { 186 return empty_java_util_arraylist; 187 } 188 } 189 return JfrJavaSupport::local_jni_handle(h_array_list(), THREAD); 190 }