1 /*
   2  * Copyright (c) 2011, 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/classLoaderData.inline.hpp"
  27 #include "classfile/symbolTable.hpp"
  28 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp"
  29 #include "jfr/utilities/jfrTypes.hpp"
  30 #include "oops/arrayKlass.inline.hpp"
  31 #include "oops/klass.inline.hpp"
  32 #include "oops/instanceKlass.inline.hpp"
  33 #include "oops/method.hpp"
  34 #include "oops/oop.inline.hpp"
  35 #include "runtime/atomic.hpp"
  36 #include "runtime/orderAccess.hpp"
  37 #include "runtime/vm_version.hpp"
  38 #include "runtime/jniHandles.inline.hpp"
  39 #include "runtime/thread.inline.hpp"
  40 #include "utilities/debug.hpp"
  41 
  42  // returns updated value
  43 static traceid atomic_inc(traceid volatile* const dest) {
  44   assert(VM_Version::supports_cx8(), "invariant");
  45   traceid compare_value;
  46   traceid exchange_value;
  47   do {
  48     compare_value = OrderAccess::load_acquire(dest);
  49     exchange_value = compare_value + 1;
  50   } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
  51   return exchange_value;
  52 }
  53 
  54 static traceid next_class_id() {
  55   static volatile traceid class_id_counter = MaxJfrEventId + 100;
  56   return atomic_inc(&class_id_counter) << TRACE_ID_SHIFT;
  57 }
  58 
  59 static traceid next_thread_id() {
  60   static volatile traceid thread_id_counter = 0;
  61   return atomic_inc(&thread_id_counter);
  62 }
  63 
  64 static traceid next_module_id() {
  65   static volatile traceid module_id_counter = 1;
  66   return atomic_inc(&module_id_counter) << TRACE_ID_SHIFT;
  67 }
  68 
  69 static traceid next_package_id() {
  70   static volatile traceid package_id_counter = 1;
  71   return atomic_inc(&package_id_counter) << TRACE_ID_SHIFT;
  72 }
  73 
  74 static traceid next_class_loader_data_id() {
  75   static volatile traceid cld_id_counter = 1;
  76   return atomic_inc(&cld_id_counter) << TRACE_ID_SHIFT;
  77 }
  78 
  79 static bool found_jdk_internal_event_klass = false;
  80 static bool found_jdk_jfr_event_klass = false;
  81 
  82 static void check_klass(const Klass* klass) {
  83   assert(klass != NULL, "invariant");
  84   if (found_jdk_internal_event_klass && found_jdk_jfr_event_klass) {
  85     return;
  86   }
  87   static const Symbol* jdk_internal_event_sym = NULL;
  88   if (jdk_internal_event_sym == NULL) {
  89     // setup when loading the first TypeArrayKlass (Universe::genesis) hence single threaded invariant
  90     jdk_internal_event_sym = SymbolTable::new_permanent_symbol("jdk/internal/event/Event", Thread::current());
  91   }
  92   assert(jdk_internal_event_sym != NULL, "invariant");
  93 
  94   static const Symbol* jdk_jfr_event_sym = NULL;
  95   if (jdk_jfr_event_sym == NULL) {
  96     // setup when loading the first TypeArrayKlass (Universe::genesis) hence single threaded invariant
  97     jdk_jfr_event_sym = SymbolTable::new_permanent_symbol("jdk/jfr/Event", Thread::current());
  98   }
  99   assert(jdk_jfr_event_sym != NULL, "invariant");
 100   const Symbol* const klass_name = klass->name();
 101 
 102   if (!found_jdk_internal_event_klass) {
 103     if (jdk_internal_event_sym == klass_name && klass->class_loader() == NULL) {
 104       found_jdk_internal_event_klass = true;
 105       JfrTraceId::tag_as_jdk_jfr_event(klass);
 106       return;
 107     }
 108   }
 109 
 110   if (!found_jdk_jfr_event_klass) {
 111     if (jdk_jfr_event_sym == klass_name && klass->class_loader() == NULL) {
 112       found_jdk_jfr_event_klass = true;
 113       JfrTraceId::tag_as_jdk_jfr_event(klass);
 114       return;
 115     }
 116   }
 117 }
 118 
 119 void JfrTraceId::assign(const Klass* klass) {
 120   assert(klass != NULL, "invariant");
 121   klass->set_trace_id(next_class_id());
 122   check_klass(klass);
 123   const Klass* const super = klass->super();
 124   if (super == NULL) {
 125     return;
 126   }
 127   if (IS_EVENT_KLASS(super)) {
 128     tag_as_jdk_jfr_event_sub(klass);
 129   }
 130 }
 131 
 132 void JfrTraceId::assign(const ModuleEntry* module) {
 133   assert(module != NULL, "invariant");
 134   module->set_trace_id(next_module_id());
 135 }
 136 
 137 void JfrTraceId::assign(const PackageEntry* package) {
 138   assert(package != NULL, "invariant");
 139   package->set_trace_id(next_package_id());
 140 }
 141 
 142 void JfrTraceId::assign(const ClassLoaderData* cld) {
 143   assert(cld != NULL, "invariant");
 144   if (cld->is_unsafe_anonymous()) {
 145     cld->set_trace_id(0);
 146     return;
 147   }
 148   cld->set_trace_id(next_class_loader_data_id());
 149 }
 150 
 151 traceid JfrTraceId::assign_thread_id() {
 152   return next_thread_id();
 153 }
 154 
 155 // used by CDS / APPCDS as part of "remove_unshareable_info"
 156 void JfrTraceId::remove(const Klass* k) {
 157   assert(k != NULL, "invariant");
 158   // Mask off and store the event flags.
 159   // This mechanism will retain the event specific flags
 160   // in the archive, allowing for event flag restoration
 161   // when renewing the traceid on klass revival.
 162   k->set_trace_id(EVENT_FLAGS_MASK(k));
 163 }
 164 
 165 // used by CDS / APPCDS as part of "restore_unshareable_info"
 166 void JfrTraceId::restore(const Klass* k) {
 167   assert(k != NULL, "invariant");
 168   if (IS_JDK_JFR_EVENT_KLASS(k)) {
 169     found_jdk_jfr_event_klass = true;
 170   }
 171   const traceid event_flags = k->trace_id();
 172   // get a fresh traceid and restore the original event flags
 173   k->set_trace_id(next_class_id() | event_flags);
 174 }
 175 
 176 traceid JfrTraceId::get(jclass jc) {
 177   assert(jc != NULL, "invariant");
 178   assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
 179   const oop my_oop = JNIHandles::resolve(jc);
 180   assert(my_oop != NULL, "invariant");
 181   return get(java_lang_Class::as_Klass(my_oop));
 182 }
 183 
 184 traceid JfrTraceId::use(jclass jc, bool leakp /* false */) {
 185   assert(jc != NULL, "invariant");
 186   assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
 187   const oop my_oop = JNIHandles::resolve(jc);
 188   assert(my_oop != NULL, "invariant");
 189   return use(java_lang_Class::as_Klass(my_oop), leakp);
 190 }
 191 
 192 bool JfrTraceId::in_visible_set(const jclass jc) {
 193   assert(jc != NULL, "invariant");
 194   assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
 195   const oop mirror = JNIHandles::resolve(jc);
 196   assert(mirror != NULL, "invariant");
 197   return in_visible_set(java_lang_Class::as_Klass(mirror));
 198 }
 199 
 200 bool JfrTraceId::in_jdk_jfr_event_hierarchy(const jclass jc) {
 201   assert(jc != NULL, "invariant");
 202   const oop mirror = JNIHandles::resolve(jc);
 203   assert(mirror != NULL, "invariant");
 204   return in_jdk_jfr_event_hierarchy(java_lang_Class::as_Klass(mirror));
 205 }
 206 
 207 bool JfrTraceId::is_jdk_jfr_event_sub(const jclass jc) {
 208   assert(jc != NULL, "invariant");
 209   const oop mirror = JNIHandles::resolve(jc);
 210   assert(mirror != NULL, "invariant");
 211   return is_jdk_jfr_event_sub(java_lang_Class::as_Klass(mirror));
 212 }
 213 
 214 bool JfrTraceId::is_jdk_jfr_event(const jclass jc) {
 215   assert(jc != NULL, "invariant");
 216   const oop mirror = JNIHandles::resolve(jc);
 217   assert(mirror != NULL, "invariant");
 218   return is_jdk_jfr_event(java_lang_Class::as_Klass(mirror));
 219 }
 220 
 221 bool JfrTraceId::is_event_host(const jclass jc) {
 222   assert(jc != NULL, "invariant");
 223   const oop mirror = JNIHandles::resolve(jc);
 224   assert(mirror != NULL, "invariant");
 225   return is_event_host(java_lang_Class::as_Klass(mirror));
 226 }
 227 
 228 void JfrTraceId::tag_as_jdk_jfr_event_sub(const jclass jc) {
 229   assert(jc != NULL, "invariant");
 230   const oop mirror = JNIHandles::resolve(jc);
 231   assert(mirror != NULL, "invariant");
 232   const Klass* const k = java_lang_Class::as_Klass(mirror);
 233   tag_as_jdk_jfr_event_sub(k);
 234   assert(IS_JDK_JFR_EVENT_SUBKLASS(k), "invariant");
 235 }
 236 
 237 void JfrTraceId::tag_as_event_host(const jclass jc) {
 238   assert(jc != NULL, "invariant");
 239   const oop mirror = JNIHandles::resolve(jc);
 240   assert(mirror != NULL, "invariant");
 241   const Klass* const k = java_lang_Class::as_Klass(mirror);
 242   tag_as_event_host(k);
 243   assert(IS_EVENT_HOST_KLASS(k), "invariant");
 244 }