1 /*
   2  * Copyright (c) 2003, 2017, 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 "interpreter/interpreter.hpp"
  27 #include "jvmtifiles/jvmtiEnv.hpp"
  28 #include "logging/log.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "prims/jvmtiEventController.hpp"
  31 #include "prims/jvmtiEventController.inline.hpp"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "prims/jvmtiImpl.hpp"
  34 #include "prims/jvmtiThreadState.inline.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/thread.hpp"
  37 #include "runtime/vframe.hpp"
  38 #include "runtime/vframe_hp.hpp"
  39 #include "runtime/vmThread.hpp"
  40 #include "runtime/vm_operations.hpp"
  41 
  42 #ifdef JVMTI_TRACE
  43 #define EC_TRACE(out) do { \
  44   if (JvmtiTrace::trace_event_controller()) { \
  45     SafeResourceMark rm; \
  46     log_trace(jvmti) out; \
  47   } \
  48 } while (0)
  49 #else
  50 #define EC_TRACE(out)
  51 #endif /*JVMTI_TRACE */
  52 
  53 // bits for standard events
  54 
  55 static const jlong  SINGLE_STEP_BIT = (((jlong)1) << (JVMTI_EVENT_SINGLE_STEP - TOTAL_MIN_EVENT_TYPE_VAL));
  56 static const jlong  FRAME_POP_BIT = (((jlong)1) << (JVMTI_EVENT_FRAME_POP - TOTAL_MIN_EVENT_TYPE_VAL));
  57 static const jlong  BREAKPOINT_BIT = (((jlong)1) << (JVMTI_EVENT_BREAKPOINT - TOTAL_MIN_EVENT_TYPE_VAL));
  58 static const jlong  FIELD_ACCESS_BIT = (((jlong)1) << (JVMTI_EVENT_FIELD_ACCESS - TOTAL_MIN_EVENT_TYPE_VAL));
  59 static const jlong  FIELD_MODIFICATION_BIT = (((jlong)1) << (JVMTI_EVENT_FIELD_MODIFICATION - TOTAL_MIN_EVENT_TYPE_VAL));
  60 static const jlong  METHOD_ENTRY_BIT = (((jlong)1) << (JVMTI_EVENT_METHOD_ENTRY - TOTAL_MIN_EVENT_TYPE_VAL));
  61 static const jlong  METHOD_EXIT_BIT = (((jlong)1) << (JVMTI_EVENT_METHOD_EXIT - TOTAL_MIN_EVENT_TYPE_VAL));
  62 static const jlong  CLASS_FILE_LOAD_HOOK_BIT = (((jlong)1) << (JVMTI_EVENT_CLASS_FILE_LOAD_HOOK - TOTAL_MIN_EVENT_TYPE_VAL));
  63 static const jlong  NATIVE_METHOD_BIND_BIT = (((jlong)1) << (JVMTI_EVENT_NATIVE_METHOD_BIND - TOTAL_MIN_EVENT_TYPE_VAL));
  64 static const jlong  VM_START_BIT = (((jlong)1) << (JVMTI_EVENT_VM_START - TOTAL_MIN_EVENT_TYPE_VAL));
  65 static const jlong  VM_INIT_BIT = (((jlong)1) << (JVMTI_EVENT_VM_INIT - TOTAL_MIN_EVENT_TYPE_VAL));
  66 static const jlong  VM_DEATH_BIT = (((jlong)1) << (JVMTI_EVENT_VM_DEATH - TOTAL_MIN_EVENT_TYPE_VAL));
  67 static const jlong  CLASS_LOAD_BIT = (((jlong)1) << (JVMTI_EVENT_CLASS_LOAD - TOTAL_MIN_EVENT_TYPE_VAL));
  68 static const jlong  CLASS_PREPARE_BIT = (((jlong)1) << (JVMTI_EVENT_CLASS_PREPARE - TOTAL_MIN_EVENT_TYPE_VAL));
  69 static const jlong  THREAD_START_BIT = (((jlong)1) << (JVMTI_EVENT_THREAD_START - TOTAL_MIN_EVENT_TYPE_VAL));
  70 static const jlong  THREAD_END_BIT = (((jlong)1) << (JVMTI_EVENT_THREAD_END - TOTAL_MIN_EVENT_TYPE_VAL));
  71 static const jlong  EXCEPTION_THROW_BIT = (((jlong)1) << (JVMTI_EVENT_EXCEPTION - TOTAL_MIN_EVENT_TYPE_VAL));
  72 static const jlong  EXCEPTION_CATCH_BIT = (((jlong)1) << (JVMTI_EVENT_EXCEPTION_CATCH - TOTAL_MIN_EVENT_TYPE_VAL));
  73 static const jlong  MONITOR_CONTENDED_ENTER_BIT = (((jlong)1) << (JVMTI_EVENT_MONITOR_CONTENDED_ENTER - TOTAL_MIN_EVENT_TYPE_VAL));
  74 static const jlong  MONITOR_CONTENDED_ENTERED_BIT = (((jlong)1) << (JVMTI_EVENT_MONITOR_CONTENDED_ENTERED - TOTAL_MIN_EVENT_TYPE_VAL));
  75 static const jlong  MONITOR_WAIT_BIT = (((jlong)1) << (JVMTI_EVENT_MONITOR_WAIT - TOTAL_MIN_EVENT_TYPE_VAL));
  76 static const jlong  MONITOR_WAITED_BIT = (((jlong)1) << (JVMTI_EVENT_MONITOR_WAITED - TOTAL_MIN_EVENT_TYPE_VAL));
  77 static const jlong  DYNAMIC_CODE_GENERATED_BIT = (((jlong)1) << (JVMTI_EVENT_DYNAMIC_CODE_GENERATED - TOTAL_MIN_EVENT_TYPE_VAL));
  78 static const jlong  DATA_DUMP_BIT = (((jlong)1) << (JVMTI_EVENT_DATA_DUMP_REQUEST - TOTAL_MIN_EVENT_TYPE_VAL));
  79 static const jlong  COMPILED_METHOD_LOAD_BIT = (((jlong)1) << (JVMTI_EVENT_COMPILED_METHOD_LOAD - TOTAL_MIN_EVENT_TYPE_VAL));
  80 static const jlong  COMPILED_METHOD_UNLOAD_BIT = (((jlong)1) << (JVMTI_EVENT_COMPILED_METHOD_UNLOAD - TOTAL_MIN_EVENT_TYPE_VAL));
  81 static const jlong  GARBAGE_COLLECTION_START_BIT = (((jlong)1) << (JVMTI_EVENT_GARBAGE_COLLECTION_START - TOTAL_MIN_EVENT_TYPE_VAL));
  82 static const jlong  GARBAGE_COLLECTION_FINISH_BIT = (((jlong)1) << (JVMTI_EVENT_GARBAGE_COLLECTION_FINISH - TOTAL_MIN_EVENT_TYPE_VAL));
  83 static const jlong  OBJECT_FREE_BIT = (((jlong)1) << (JVMTI_EVENT_OBJECT_FREE - TOTAL_MIN_EVENT_TYPE_VAL));
  84 static const jlong  RESOURCE_EXHAUSTED_BIT = (((jlong)1) << (JVMTI_EVENT_RESOURCE_EXHAUSTED - TOTAL_MIN_EVENT_TYPE_VAL));
  85 static const jlong  VM_OBJECT_ALLOC_BIT = (((jlong)1) << (JVMTI_EVENT_VM_OBJECT_ALLOC - TOTAL_MIN_EVENT_TYPE_VAL));
  86 
  87 // bits for extension events
  88 static const jlong  CLASS_UNLOAD_BIT = (((jlong)1) << (EXT_EVENT_CLASS_UNLOAD - TOTAL_MIN_EVENT_TYPE_VAL));
  89 
  90 
  91 static const jlong  MONITOR_BITS = MONITOR_CONTENDED_ENTER_BIT | MONITOR_CONTENDED_ENTERED_BIT |
  92                           MONITOR_WAIT_BIT | MONITOR_WAITED_BIT;
  93 static const jlong  EXCEPTION_BITS = EXCEPTION_THROW_BIT | EXCEPTION_CATCH_BIT;
  94 static const jlong  INTERP_EVENT_BITS =  SINGLE_STEP_BIT | METHOD_ENTRY_BIT | METHOD_EXIT_BIT |
  95                                 FRAME_POP_BIT | FIELD_ACCESS_BIT | FIELD_MODIFICATION_BIT;
  96 static const jlong  THREAD_FILTERED_EVENT_BITS = INTERP_EVENT_BITS | EXCEPTION_BITS | MONITOR_BITS |
  97                                         BREAKPOINT_BIT | CLASS_LOAD_BIT | CLASS_PREPARE_BIT | THREAD_END_BIT;
  98 static const jlong  NEED_THREAD_LIFE_EVENTS = THREAD_FILTERED_EVENT_BITS | THREAD_START_BIT;
  99 static const jlong  EARLY_EVENT_BITS = CLASS_FILE_LOAD_HOOK_BIT | CLASS_LOAD_BIT | CLASS_PREPARE_BIT |
 100                                VM_START_BIT | VM_INIT_BIT | VM_DEATH_BIT | NATIVE_METHOD_BIND_BIT |
 101                                THREAD_START_BIT | THREAD_END_BIT |
 102                                COMPILED_METHOD_LOAD_BIT | COMPILED_METHOD_UNLOAD_BIT |
 103                                DYNAMIC_CODE_GENERATED_BIT;
 104 static const jlong  GLOBAL_EVENT_BITS = ~THREAD_FILTERED_EVENT_BITS;
 105 static const jlong  SHOULD_POST_ON_EXCEPTIONS_BITS = EXCEPTION_BITS | METHOD_EXIT_BIT | FRAME_POP_BIT;
 106 
 107 ///////////////////////////////////////////////////////////////
 108 //
 109 // JvmtiEventEnabled
 110 //
 111 
 112 JvmtiEventEnabled::JvmtiEventEnabled() {
 113   clear();
 114 }
 115 
 116 
 117 void JvmtiEventEnabled::clear() {
 118   _enabled_bits = 0;
 119 #ifndef PRODUCT
 120   _init_guard = JEE_INIT_GUARD;
 121 #endif
 122 }
 123 
 124 void JvmtiEventEnabled::set_enabled(jvmtiEvent event_type, bool enabled) {
 125   jlong bits = get_bits();
 126   jlong mask = bit_for(event_type);
 127   if (enabled) {
 128     bits |= mask;
 129   } else {
 130     bits &= ~mask;
 131   }
 132   set_bits(bits);
 133 }
 134 
 135 
 136 ///////////////////////////////////////////////////////////////
 137 //
 138 // JvmtiEnvThreadEventEnable
 139 //
 140 
 141 JvmtiEnvThreadEventEnable::JvmtiEnvThreadEventEnable() {
 142   _event_user_enabled.clear();
 143   _event_enabled.clear();
 144 }
 145 
 146 
 147 JvmtiEnvThreadEventEnable::~JvmtiEnvThreadEventEnable() {
 148   _event_user_enabled.clear();
 149   _event_enabled.clear();
 150 }
 151 
 152 
 153 ///////////////////////////////////////////////////////////////
 154 //
 155 // JvmtiThreadEventEnable
 156 //
 157 
 158 JvmtiThreadEventEnable::JvmtiThreadEventEnable() {
 159   _event_enabled.clear();
 160 }
 161 
 162 
 163 JvmtiThreadEventEnable::~JvmtiThreadEventEnable() {
 164   _event_enabled.clear();
 165 }
 166 
 167 
 168 ///////////////////////////////////////////////////////////////
 169 //
 170 // JvmtiEnvEventEnable
 171 //
 172 
 173 JvmtiEnvEventEnable::JvmtiEnvEventEnable() {
 174   _event_user_enabled.clear();
 175   _event_callback_enabled.clear();
 176   _event_enabled.clear();
 177 }
 178 
 179 
 180 JvmtiEnvEventEnable::~JvmtiEnvEventEnable() {
 181   _event_user_enabled.clear();
 182   _event_callback_enabled.clear();
 183   _event_enabled.clear();
 184 }
 185 
 186 
 187 ///////////////////////////////////////////////////////////////
 188 //
 189 // VM_EnterInterpOnlyMode
 190 //
 191 
 192 class VM_EnterInterpOnlyMode : public VM_Operation {
 193 private:
 194   JvmtiThreadState *_state;
 195 
 196 public:
 197   VM_EnterInterpOnlyMode(JvmtiThreadState *state);
 198 
 199   bool allow_nested_vm_operations() const        { return true; }
 200   VMOp_Type type() const { return VMOp_EnterInterpOnlyMode; }
 201   void doit();
 202 
 203   // to do: this same function is in jvmtiImpl - should be in one place
 204   bool can_be_deoptimized(vframe* vf) {
 205     return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
 206   }
 207 };
 208 
 209 VM_EnterInterpOnlyMode::VM_EnterInterpOnlyMode(JvmtiThreadState *state)
 210   : _state(state)
 211 {
 212 }
 213 
 214 
 215 void VM_EnterInterpOnlyMode::doit() {
 216   // Set up the current stack depth for later tracking
 217   _state->invalidate_cur_stack_depth();
 218 
 219   _state->enter_interp_only_mode();
 220 
 221   JavaThread *thread = _state->get_thread();
 222   if (thread->has_last_Java_frame()) {
 223     // If running in fullspeed mode, single stepping is implemented
 224     // as follows: first, the interpreter does not dispatch to
 225     // compiled code for threads that have single stepping enabled;
 226     // second, we deoptimize all methods on the thread's stack when
 227     // interpreted-only mode is enabled the first time for a given
 228     // thread (nothing to do if no Java frames yet).
 229     int num_marked = 0;
 230     ResourceMark resMark;
 231     RegisterMap rm(thread, false);
 232     for (vframe* vf = thread->last_java_vframe(&rm); vf; vf = vf->sender()) {
 233       if (can_be_deoptimized(vf)) {
 234         ((compiledVFrame*) vf)->code()->mark_for_deoptimization();
 235         ++num_marked;
 236       }
 237     }
 238     if (num_marked > 0) {
 239       VM_Deoptimize op;
 240       VMThread::execute(&op);
 241     }
 242   }
 243 }
 244 
 245 
 246 ///////////////////////////////////////////////////////////////
 247 //
 248 // VM_ChangeSingleStep
 249 //
 250 
 251 class VM_ChangeSingleStep : public VM_Operation {
 252 private:
 253   bool _on;
 254 
 255 public:
 256   VM_ChangeSingleStep(bool on);
 257   VMOp_Type type() const                         { return VMOp_ChangeSingleStep; }
 258   bool allow_nested_vm_operations() const        { return true; }
 259   void doit();   // method definition is after definition of JvmtiEventControllerPrivate because of scoping
 260 };
 261 
 262 
 263 VM_ChangeSingleStep::VM_ChangeSingleStep(bool on)
 264   : _on(on != 0)
 265 {
 266 }
 267 
 268 
 269 
 270 
 271 ///////////////////////////////////////////////////////////////
 272 //
 273 // JvmtiEventControllerPrivate
 274 //
 275 // Private internal implementation methods for JvmtiEventController.
 276 //
 277 // These methods are thread safe either because they are called
 278 // in early VM initialization which is single threaded, or they
 279 // hold the JvmtiThreadState_lock.
 280 //
 281 
 282 class JvmtiEventControllerPrivate : public AllStatic {
 283   static bool _initialized;
 284 public:
 285   static void set_should_post_single_step(bool on);
 286   static void enter_interp_only_mode(JvmtiThreadState *state);
 287   static void leave_interp_only_mode(JvmtiThreadState *state);
 288   static void recompute_enabled();
 289   static jlong recompute_env_enabled(JvmtiEnvBase* env);
 290   static jlong recompute_env_thread_enabled(JvmtiEnvThreadState* ets, JvmtiThreadState* state);
 291   static jlong recompute_thread_enabled(JvmtiThreadState *state);
 292   static void event_init();
 293 
 294   static void set_user_enabled(JvmtiEnvBase *env, JavaThread *thread,
 295                         jvmtiEvent event_type, bool enabled);
 296   static void set_event_callbacks(JvmtiEnvBase *env,
 297                                   const jvmtiEventCallbacks* callbacks,
 298                                   jint size_of_callbacks);
 299 
 300   static void set_extension_event_callback(JvmtiEnvBase *env,
 301                                            jint extension_event_index,
 302                                            jvmtiExtensionEvent callback);
 303 
 304   static void set_frame_pop(JvmtiEnvThreadState *env_thread, JvmtiFramePop fpop);
 305   static void clear_frame_pop(JvmtiEnvThreadState *env_thread, JvmtiFramePop fpop);
 306   static void clear_to_frame_pop(JvmtiEnvThreadState *env_thread, JvmtiFramePop fpop);
 307   static void change_field_watch(jvmtiEvent event_type, bool added);
 308 
 309   static void thread_started(JavaThread *thread);
 310   static void thread_ended(JavaThread *thread);
 311 
 312   static void env_initialize(JvmtiEnvBase *env);
 313   static void env_dispose(JvmtiEnvBase *env);
 314 
 315   static void vm_start();
 316   static void vm_init();
 317   static void vm_death();
 318 
 319   static void trace_changed(JvmtiThreadState *state, jlong now_enabled, jlong changed);
 320   static void trace_changed(jlong now_enabled, jlong changed);
 321 };
 322 
 323 bool JvmtiEventControllerPrivate::_initialized = false;
 324 
 325 void JvmtiEventControllerPrivate::set_should_post_single_step(bool on) {
 326   // we have permission to do this, VM op doesn't
 327   JvmtiExport::set_should_post_single_step(on);
 328 }
 329 
 330 
 331 // This change must always be occur when at a safepoint.
 332 // Being at a safepoint causes the interpreter to use the
 333 // safepoint dispatch table which we overload to find single
 334 // step points.  Just to be sure that it has been set, we
 335 // call notice_safepoints when turning on single stepping.
 336 // When we leave our current safepoint, should_post_single_step
 337 // will be checked by the interpreter, and the table kept
 338 // or changed accordingly.
 339 void VM_ChangeSingleStep::doit() {
 340   JvmtiEventControllerPrivate::set_should_post_single_step(_on);
 341   if (_on) {
 342     Interpreter::notice_safepoints();
 343   }
 344 }
 345 
 346 
 347 void JvmtiEventControllerPrivate::enter_interp_only_mode(JvmtiThreadState *state) {
 348   EC_TRACE(("[%s] # Entering interpreter only mode",
 349             JvmtiTrace::safe_get_thread_name(state->get_thread())));
 350 
 351   VM_EnterInterpOnlyMode op(state);
 352   VMThread::execute(&op);
 353 }
 354 
 355 
 356 void
 357 JvmtiEventControllerPrivate::leave_interp_only_mode(JvmtiThreadState *state) {
 358   EC_TRACE(("[%s] # Leaving interpreter only mode",
 359             JvmtiTrace::safe_get_thread_name(state->get_thread())));
 360   state->leave_interp_only_mode();
 361 }
 362 
 363 
 364 void
 365 JvmtiEventControllerPrivate::trace_changed(JvmtiThreadState *state, jlong now_enabled, jlong changed) {
 366 #ifdef JVMTI_TRACE
 367   if (JvmtiTrace::trace_event_controller()) {
 368     SafeResourceMark rm;
 369     // traces standard events only
 370     for (int ei = JVMTI_MIN_EVENT_TYPE_VAL; ei <= JVMTI_MAX_EVENT_TYPE_VAL; ++ei) {
 371       jlong bit = JvmtiEventEnabled::bit_for((jvmtiEvent)ei);
 372       if (changed & bit) {
 373         // it changed, print it
 374          log_trace(jvmti)("[%s] # %s event %s",
 375                       JvmtiTrace::safe_get_thread_name(state->get_thread()),
 376                       (now_enabled & bit)? "Enabling" : "Disabling", JvmtiTrace::event_name((jvmtiEvent)ei));
 377       }
 378     }
 379   }
 380 #endif /*JVMTI_TRACE */
 381 }
 382 
 383 
 384 void
 385 JvmtiEventControllerPrivate::trace_changed(jlong now_enabled, jlong changed) {
 386 #ifdef JVMTI_TRACE
 387   if (JvmtiTrace::trace_event_controller()) {
 388     SafeResourceMark rm;
 389     // traces standard events only
 390     for (int ei = JVMTI_MIN_EVENT_TYPE_VAL; ei <= JVMTI_MAX_EVENT_TYPE_VAL; ++ei) {
 391       jlong bit = JvmtiEventEnabled::bit_for((jvmtiEvent)ei);
 392       if (changed & bit) {
 393         // it changed, print it
 394          log_trace(jvmti)("[-] # %s event %s",
 395                       (now_enabled & bit)? "Enabling" : "Disabling", JvmtiTrace::event_name((jvmtiEvent)ei));
 396       }
 397     }
 398   }
 399 #endif /*JVMTI_TRACE */
 400 }
 401 
 402 
 403 // For the specified env: compute the currently truly enabled events
 404 // set external state accordingly.
 405 // Return value and set value must include all events.
 406 // But outside this class, only non-thread-filtered events can be queried..
 407 jlong
 408 JvmtiEventControllerPrivate::recompute_env_enabled(JvmtiEnvBase* env) {
 409   jlong was_enabled = env->env_event_enable()->_event_enabled.get_bits();
 410   jlong now_enabled =
 411     env->env_event_enable()->_event_callback_enabled.get_bits() &
 412     env->env_event_enable()->_event_user_enabled.get_bits();
 413 
 414   switch (env->phase()) {
 415   case JVMTI_PHASE_PRIMORDIAL:
 416   case JVMTI_PHASE_ONLOAD:
 417     // only these events allowed in primordial or onload phase
 418     now_enabled &= (EARLY_EVENT_BITS & ~THREAD_FILTERED_EVENT_BITS);
 419     break;
 420   case JVMTI_PHASE_START:
 421     // only these events allowed in start phase
 422     now_enabled &= EARLY_EVENT_BITS;
 423     break;
 424   case JVMTI_PHASE_LIVE:
 425     // all events allowed during live phase
 426     break;
 427   case JVMTI_PHASE_DEAD:
 428     // no events allowed when dead
 429     now_enabled = 0;
 430     break;
 431   default:
 432     assert(false, "no other phases - sanity check");
 433     break;
 434   }
 435 
 436   // will we really send these events to this env
 437   env->env_event_enable()->_event_enabled.set_bits(now_enabled);
 438 
 439   trace_changed(now_enabled, (now_enabled ^ was_enabled)  & ~THREAD_FILTERED_EVENT_BITS);
 440 
 441   return now_enabled;
 442 }
 443 
 444 
 445 // For the specified env and thread: compute the currently truly enabled events
 446 // set external state accordingly.  Only thread-filtered events are included.
 447 jlong
 448 JvmtiEventControllerPrivate::recompute_env_thread_enabled(JvmtiEnvThreadState* ets, JvmtiThreadState* state) {
 449   JvmtiEnv *env = ets->get_env();
 450 
 451   jlong was_enabled = ets->event_enable()->_event_enabled.get_bits();
 452   jlong now_enabled =  THREAD_FILTERED_EVENT_BITS &
 453     env->env_event_enable()->_event_callback_enabled.get_bits() &
 454     (env->env_event_enable()->_event_user_enabled.get_bits() |
 455      ets->event_enable()->_event_user_enabled.get_bits());
 456 
 457   // for frame pops and field watchs, computed enabled state
 458   // is only true if an event has been requested
 459   if (!ets->has_frame_pops()) {
 460     now_enabled &= ~FRAME_POP_BIT;
 461   }
 462   if (*((int *)JvmtiExport::get_field_access_count_addr()) == 0) {
 463     now_enabled &= ~FIELD_ACCESS_BIT;
 464   }
 465   if (*((int *)JvmtiExport::get_field_modification_count_addr()) == 0) {
 466     now_enabled &= ~FIELD_MODIFICATION_BIT;
 467   }
 468 
 469   switch (JvmtiEnv::get_phase()) {
 470   case JVMTI_PHASE_DEAD:
 471     // no events allowed when dead
 472     now_enabled = 0;
 473     break;
 474   default:
 475     break;
 476   }
 477 
 478   // if anything changed do update
 479   if (now_enabled != was_enabled) {
 480 
 481     // will we really send these events to this thread x env
 482     ets->event_enable()->_event_enabled.set_bits(now_enabled);
 483 
 484     // If the enabled status of the single step or breakpoint events changed,
 485     // the location status may need to change as well.
 486     jlong changed = now_enabled ^ was_enabled;
 487     if (changed & SINGLE_STEP_BIT) {
 488       ets->reset_current_location(JVMTI_EVENT_SINGLE_STEP, (now_enabled & SINGLE_STEP_BIT) != 0);
 489     }
 490     if (changed & BREAKPOINT_BIT) {
 491       ets->reset_current_location(JVMTI_EVENT_BREAKPOINT,  (now_enabled & BREAKPOINT_BIT) != 0);
 492     }
 493     trace_changed(state, now_enabled, changed);
 494   }
 495   return now_enabled;
 496 }
 497 
 498 
 499 // For the specified thread: compute the currently truly enabled events
 500 // set external state accordingly.  Only thread-filtered events are included.
 501 jlong
 502 JvmtiEventControllerPrivate::recompute_thread_enabled(JvmtiThreadState *state) {
 503   if (state == NULL) {
 504     // associated JavaThread is exiting
 505     return (jlong)0;
 506   }
 507 
 508   julong was_any_env_enabled = state->thread_event_enable()->_event_enabled.get_bits();
 509   julong any_env_enabled = 0;
 510 
 511   {
 512     // This iteration will include JvmtiEnvThreadStates whoses environments
 513     // have been disposed.  These JvmtiEnvThreadStates must not be filtered
 514     // as recompute must be called on them to disable their events,
 515     JvmtiEnvThreadStateIterator it(state);
 516     for (JvmtiEnvThreadState* ets = it.first(); ets != NULL; ets = it.next(ets)) {
 517       any_env_enabled |= recompute_env_thread_enabled(ets, state);
 518     }
 519   }
 520 
 521   if (any_env_enabled != was_any_env_enabled) {
 522     // mark if event is truly enabled on this thread in any environment
 523     state->thread_event_enable()->_event_enabled.set_bits(any_env_enabled);
 524 
 525     // compute interp_only mode
 526     bool should_be_interp = (any_env_enabled & INTERP_EVENT_BITS) != 0;
 527     bool is_now_interp = state->is_interp_only_mode();
 528 
 529     if (should_be_interp != is_now_interp) {
 530       if (should_be_interp) {
 531         enter_interp_only_mode(state);
 532       } else {
 533         leave_interp_only_mode(state);
 534       }
 535     }
 536 
 537     // update the JavaThread cached value for thread-specific should_post_on_exceptions value
 538     bool should_post_on_exceptions = (any_env_enabled & SHOULD_POST_ON_EXCEPTIONS_BITS) != 0;
 539     state->set_should_post_on_exceptions(should_post_on_exceptions);
 540   }
 541 
 542   return any_env_enabled;
 543 }
 544 
 545 
 546 // Compute truly enabled events - meaning if the event can and could be
 547 // sent.  An event is truly enabled if it is user enabled on the thread
 548 // or globally user enabled, but only if there is a callback or event hook
 549 // for it and, for field watch and frame pop, one has been set.
 550 // Compute if truly enabled, per thread, per environment, per combination
 551 // (thread x environment), and overall.  These merges are true if any is true.
 552 // True per thread if some environment has callback set and the event is globally
 553 // enabled or enabled for this thread.
 554 // True per environment if the callback is set and the event is globally
 555 // enabled in this environment or enabled for any thread in this environment.
 556 // True per combination if the environment has the callback set and the
 557 // event is globally enabled in this environment or the event is enabled
 558 // for this thread and environment.
 559 //
 560 // All states transitions dependent on these transitions are also handled here.
 561 void
 562 JvmtiEventControllerPrivate::recompute_enabled() {
 563   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 564 
 565   // event enabled for any thread in any environment
 566   julong was_any_env_thread_enabled = JvmtiEventController::_universal_global_event_enabled.get_bits();
 567   julong any_env_thread_enabled = 0;
 568 
 569   EC_TRACE(("[-] # recompute enabled - before " JULONG_FORMAT_X, was_any_env_thread_enabled));
 570 
 571   // compute non-thread-filters events.
 572   // This must be done separately from thread-filtered events, since some
 573   // events can occur before any threads exist.
 574   JvmtiEnvIterator it;
 575   for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
 576     any_env_thread_enabled |= recompute_env_enabled(env);
 577   }
 578 
 579   // We need to create any missing jvmti_thread_state if there are globally set thread
 580   // filtered events and there weren't last time
 581   if (    (any_env_thread_enabled & THREAD_FILTERED_EVENT_BITS) != 0 &&
 582       (was_any_env_thread_enabled & THREAD_FILTERED_EVENT_BITS) == 0) {
 583     {
 584       MutexLocker mu(Threads_lock);   //hold the Threads_lock for the iteration
 585       for (JavaThread *tp = Threads::first(); tp != NULL; tp = tp->next()) {
 586         // state_for_while_locked() makes tp->is_exiting() check
 587         JvmtiThreadState::state_for_while_locked(tp);  // create the thread state if missing
 588       }
 589     }// release Threads_lock
 590   }
 591 
 592   // compute and set thread-filtered events
 593   for (JvmtiThreadState *state = JvmtiThreadState::first(); state != NULL; state = state->next()) {
 594     any_env_thread_enabled |= recompute_thread_enabled(state);
 595   }
 596 
 597   // set universal state (across all envs and threads)
 598   jlong delta = any_env_thread_enabled ^ was_any_env_thread_enabled;
 599   if (delta != 0) {
 600     JvmtiExport::set_should_post_field_access((any_env_thread_enabled & FIELD_ACCESS_BIT) != 0);
 601     JvmtiExport::set_should_post_field_modification((any_env_thread_enabled & FIELD_MODIFICATION_BIT) != 0);
 602     JvmtiExport::set_should_post_class_load((any_env_thread_enabled & CLASS_LOAD_BIT) != 0);
 603     JvmtiExport::set_should_post_class_file_load_hook((any_env_thread_enabled & CLASS_FILE_LOAD_HOOK_BIT) != 0);
 604     JvmtiExport::set_should_post_native_method_bind((any_env_thread_enabled & NATIVE_METHOD_BIND_BIT) != 0);
 605     JvmtiExport::set_should_post_dynamic_code_generated((any_env_thread_enabled & DYNAMIC_CODE_GENERATED_BIT) != 0);
 606     JvmtiExport::set_should_post_data_dump((any_env_thread_enabled & DATA_DUMP_BIT) != 0);
 607     JvmtiExport::set_should_post_class_prepare((any_env_thread_enabled & CLASS_PREPARE_BIT) != 0);
 608     JvmtiExport::set_should_post_class_unload((any_env_thread_enabled & CLASS_UNLOAD_BIT) != 0);
 609     JvmtiExport::set_should_post_monitor_contended_enter((any_env_thread_enabled & MONITOR_CONTENDED_ENTER_BIT) != 0);
 610     JvmtiExport::set_should_post_monitor_contended_entered((any_env_thread_enabled & MONITOR_CONTENDED_ENTERED_BIT) != 0);
 611     JvmtiExport::set_should_post_monitor_wait((any_env_thread_enabled & MONITOR_WAIT_BIT) != 0);
 612     JvmtiExport::set_should_post_monitor_waited((any_env_thread_enabled & MONITOR_WAITED_BIT) != 0);
 613     JvmtiExport::set_should_post_garbage_collection_start((any_env_thread_enabled & GARBAGE_COLLECTION_START_BIT) != 0);
 614     JvmtiExport::set_should_post_garbage_collection_finish((any_env_thread_enabled & GARBAGE_COLLECTION_FINISH_BIT) != 0);
 615     JvmtiExport::set_should_post_object_free((any_env_thread_enabled & OBJECT_FREE_BIT) != 0);
 616     JvmtiExport::set_should_post_resource_exhausted((any_env_thread_enabled & RESOURCE_EXHAUSTED_BIT) != 0);
 617     JvmtiExport::set_should_post_compiled_method_load((any_env_thread_enabled & COMPILED_METHOD_LOAD_BIT) != 0);
 618     JvmtiExport::set_should_post_compiled_method_unload((any_env_thread_enabled & COMPILED_METHOD_UNLOAD_BIT) != 0);
 619     JvmtiExport::set_should_post_vm_object_alloc((any_env_thread_enabled & VM_OBJECT_ALLOC_BIT) != 0);
 620 
 621     // need this if we want thread events or we need them to init data
 622     JvmtiExport::set_should_post_thread_life((any_env_thread_enabled & NEED_THREAD_LIFE_EVENTS) != 0);
 623 
 624     // If single stepping is turned on or off, execute the VM op to change it.
 625     if (delta & SINGLE_STEP_BIT) {
 626       switch (JvmtiEnv::get_phase()) {
 627       case JVMTI_PHASE_DEAD:
 628         // If the VM is dying we can't execute VM ops
 629         break;
 630       case JVMTI_PHASE_LIVE: {
 631         VM_ChangeSingleStep op((any_env_thread_enabled & SINGLE_STEP_BIT) != 0);
 632         VMThread::execute(&op);
 633         break;
 634       }
 635       default:
 636         assert(false, "should never come here before live phase");
 637         break;
 638       }
 639     }
 640 
 641     // set global truly enabled, that is, any thread in any environment
 642     JvmtiEventController::_universal_global_event_enabled.set_bits(any_env_thread_enabled);
 643 
 644     // set global should_post_on_exceptions
 645     JvmtiExport::set_should_post_on_exceptions((any_env_thread_enabled & SHOULD_POST_ON_EXCEPTIONS_BITS) != 0);
 646 
 647   }
 648 
 649   EC_TRACE(("[-] # recompute enabled - after " JULONG_FORMAT_X, any_env_thread_enabled));
 650 }
 651 
 652 
 653 void
 654 JvmtiEventControllerPrivate::thread_started(JavaThread *thread) {
 655   assert(thread->is_Java_thread(), "Must be JavaThread");
 656   assert(thread == Thread::current(), "must be current thread");
 657   assert(JvmtiEnvBase::environments_might_exist(), "to enter event controller, JVM TI environments must exist");
 658 
 659   EC_TRACE(("[%s] # thread started", JvmtiTrace::safe_get_thread_name(thread)));
 660 
 661   // if we have any thread filtered events globally enabled, create/update the thread state
 662   if ((JvmtiEventController::_universal_global_event_enabled.get_bits() & THREAD_FILTERED_EVENT_BITS) != 0) {
 663     MutexLocker mu(JvmtiThreadState_lock);
 664     // create the thread state if missing
 665     JvmtiThreadState *state = JvmtiThreadState::state_for_while_locked(thread);
 666     if (state != NULL) {    // skip threads with no JVMTI thread state
 667       recompute_thread_enabled(state);
 668     }
 669   }
 670 }
 671 
 672 
 673 void
 674 JvmtiEventControllerPrivate::thread_ended(JavaThread *thread) {
 675   // Removes the JvmtiThreadState associated with the specified thread.
 676   // May be called after all environments have been disposed.
 677   assert(JvmtiThreadState_lock->is_locked(), "sanity check");
 678 
 679   EC_TRACE(("[%s] # thread ended", JvmtiTrace::safe_get_thread_name(thread)));
 680 
 681   JvmtiThreadState *state = thread->jvmti_thread_state();
 682   assert(state != NULL, "else why are we here?");
 683   delete state;
 684 }
 685 
 686 void JvmtiEventControllerPrivate::set_event_callbacks(JvmtiEnvBase *env,
 687                                                       const jvmtiEventCallbacks* callbacks,
 688                                                       jint size_of_callbacks) {
 689   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 690   EC_TRACE(("[*] # set event callbacks"));
 691 
 692   env->set_event_callbacks(callbacks, size_of_callbacks);
 693   jlong enabled_bits = 0;
 694   for (int ei = JVMTI_MIN_EVENT_TYPE_VAL; ei <= JVMTI_MAX_EVENT_TYPE_VAL; ++ei) {
 695     jvmtiEvent evt_t = (jvmtiEvent)ei;
 696     if (env->has_callback(evt_t)) {
 697       enabled_bits |= JvmtiEventEnabled::bit_for(evt_t);
 698     }
 699   }
 700   env->env_event_enable()->_event_callback_enabled.set_bits(enabled_bits);
 701   recompute_enabled();
 702 }
 703 
 704 void
 705 JvmtiEventControllerPrivate::set_extension_event_callback(JvmtiEnvBase *env,
 706                                                           jint extension_event_index,
 707                                                           jvmtiExtensionEvent callback)
 708 {
 709   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 710   EC_TRACE(("[*] # set extension event callback"));
 711 
 712   // extension events are allocated below JVMTI_MIN_EVENT_TYPE_VAL
 713   assert(extension_event_index >= (jint)EXT_MIN_EVENT_TYPE_VAL &&
 714          extension_event_index <= (jint)EXT_MAX_EVENT_TYPE_VAL, "sanity check");
 715 
 716 
 717   // As the bits for both standard (jvmtiEvent) and extension
 718   // (jvmtiExtEvents) are stored in the same word we cast here to
 719   // jvmtiEvent to set/clear the bit for this extension event.
 720   jvmtiEvent event_type = (jvmtiEvent)extension_event_index;
 721 
 722   // Prevent a possible race condition where events are re-enabled by a call to
 723   // set event callbacks, where the DisposeEnvironment occurs after the boiler-plate
 724   // environment check and before the lock is acquired.
 725   // We can safely do the is_valid check now, as JvmtiThreadState_lock is held.
 726   bool enabling = (callback != NULL) && (env->is_valid());
 727   env->env_event_enable()->set_user_enabled(event_type, enabling);
 728 
 729   // update the callback
 730   jvmtiExtEventCallbacks* ext_callbacks = env->ext_callbacks();
 731   switch (extension_event_index) {
 732     case EXT_EVENT_CLASS_UNLOAD :
 733       ext_callbacks->ClassUnload = callback;
 734       break;
 735     default:
 736       ShouldNotReachHere();
 737   }
 738 
 739   // update the callback enable/disable bit
 740   jlong enabled_bits = env->env_event_enable()->_event_callback_enabled.get_bits();
 741   jlong bit_for = JvmtiEventEnabled::bit_for(event_type);
 742   if (enabling) {
 743     enabled_bits |= bit_for;
 744   } else {
 745     enabled_bits &= ~bit_for;
 746   }
 747   env->env_event_enable()->_event_callback_enabled.set_bits(enabled_bits);
 748 
 749   recompute_enabled();
 750 }
 751 
 752 
 753 void
 754 JvmtiEventControllerPrivate::env_initialize(JvmtiEnvBase *env) {
 755   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 756   EC_TRACE(("[*] # env initialize"));
 757 
 758   if (JvmtiEnvBase::is_vm_live()) {
 759     // if we didn't initialize event info already (this is a late
 760     // launched environment), do it now.
 761     event_init();
 762   }
 763 
 764   env->initialize();
 765 
 766   // add the JvmtiEnvThreadState to each JvmtiThreadState
 767   for (JvmtiThreadState *state = JvmtiThreadState::first(); state != NULL; state = state->next()) {
 768     state->add_env(env);
 769     assert((JvmtiEnv*)(state->env_thread_state(env)->get_env()) == env, "sanity check");
 770   }
 771   JvmtiEventControllerPrivate::recompute_enabled();
 772 }
 773 
 774 
 775 void
 776 JvmtiEventControllerPrivate::env_dispose(JvmtiEnvBase *env) {
 777   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 778   EC_TRACE(("[*] # env dispose"));
 779 
 780   // Before the environment is marked disposed, disable all events on this
 781   // environment (by zapping the callbacks).  As a result, the disposed
 782   // environment will not call event handlers.
 783   set_event_callbacks(env, NULL, 0);
 784   for (jint extension_event_index = EXT_MIN_EVENT_TYPE_VAL;
 785        extension_event_index <= EXT_MAX_EVENT_TYPE_VAL;
 786        ++extension_event_index) {
 787     set_extension_event_callback(env, extension_event_index, NULL);
 788   }
 789 
 790   // Let the environment finish disposing itself.
 791   env->env_dispose();
 792 }
 793 
 794 
 795 void
 796 JvmtiEventControllerPrivate::set_user_enabled(JvmtiEnvBase *env, JavaThread *thread,
 797                                           jvmtiEvent event_type, bool enabled) {
 798   assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
 799 
 800   EC_TRACE(("[%s] # user %s event %s",
 801             thread==NULL? "ALL": JvmtiTrace::safe_get_thread_name(thread),
 802             enabled? "enabled" : "disabled", JvmtiTrace::event_name(event_type)));
 803 
 804   if (thread == NULL) {
 805     env->env_event_enable()->set_user_enabled(event_type, enabled);
 806   } else {
 807     // create the thread state (if it didn't exist before)
 808     JvmtiThreadState *state = JvmtiThreadState::state_for_while_locked(thread);
 809     if (state != NULL) {
 810       state->env_thread_state(env)->event_enable()->set_user_enabled(event_type, enabled);
 811     }
 812   }
 813   recompute_enabled();
 814 }
 815 
 816 
 817 void
 818 JvmtiEventControllerPrivate::set_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
 819   EC_TRACE(("[%s] # set frame pop - frame=%d",
 820             JvmtiTrace::safe_get_thread_name(ets->get_thread()),
 821             fpop.frame_number() ));
 822 
 823   ets->get_frame_pops()->set(fpop);
 824   recompute_thread_enabled(ets->get_thread()->jvmti_thread_state());
 825 }
 826 
 827 
 828 void
 829 JvmtiEventControllerPrivate::clear_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
 830   EC_TRACE(("[%s] # clear frame pop - frame=%d",
 831             JvmtiTrace::safe_get_thread_name(ets->get_thread()),
 832             fpop.frame_number() ));
 833 
 834   ets->get_frame_pops()->clear(fpop);
 835   recompute_thread_enabled(ets->get_thread()->jvmti_thread_state());
 836 }
 837 
 838 
 839 void
 840 JvmtiEventControllerPrivate::clear_to_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
 841   int cleared_cnt = ets->get_frame_pops()->clear_to(fpop);
 842 
 843   EC_TRACE(("[%s] # clear to frame pop - frame=%d, count=%d",
 844             JvmtiTrace::safe_get_thread_name(ets->get_thread()),
 845             fpop.frame_number(),
 846             cleared_cnt ));
 847 
 848   if (cleared_cnt > 0) {
 849     recompute_thread_enabled(ets->get_thread()->jvmti_thread_state());
 850   }
 851 }
 852 
 853 void
 854 JvmtiEventControllerPrivate::change_field_watch(jvmtiEvent event_type, bool added) {
 855   int *count_addr;
 856 
 857   switch (event_type) {
 858   case JVMTI_EVENT_FIELD_MODIFICATION:
 859     count_addr = (int *)JvmtiExport::get_field_modification_count_addr();
 860     break;
 861   case JVMTI_EVENT_FIELD_ACCESS:
 862     count_addr = (int *)JvmtiExport::get_field_access_count_addr();
 863     break;
 864   default:
 865     assert(false, "incorrect event");
 866     return;
 867   }
 868 
 869   EC_TRACE(("[-] # change field watch - %s %s count=%d",
 870             event_type==JVMTI_EVENT_FIELD_MODIFICATION? "modification" : "access",
 871             added? "add" : "remove",
 872             *count_addr));
 873 
 874   if (added) {
 875     (*count_addr)++;
 876     if (*count_addr == 1) {
 877       recompute_enabled();
 878     }
 879   } else {
 880     if (*count_addr > 0) {
 881       (*count_addr)--;
 882       if (*count_addr == 0) {
 883         recompute_enabled();
 884       }
 885     } else {
 886       assert(false, "field watch out of phase");
 887     }
 888   }
 889 }
 890 
 891 void
 892 JvmtiEventControllerPrivate::event_init() {
 893   assert(JvmtiThreadState_lock->is_locked(), "sanity check");
 894 
 895   if (_initialized) {
 896     return;
 897   }
 898 
 899   EC_TRACE(("[-] # VM live"));
 900 
 901 #ifdef ASSERT
 902   // check that our idea and the spec's idea of threaded events match
 903   for (int ei = JVMTI_MIN_EVENT_TYPE_VAL; ei <= JVMTI_MAX_EVENT_TYPE_VAL; ++ei) {
 904     jlong bit = JvmtiEventEnabled::bit_for((jvmtiEvent)ei);
 905     assert(((THREAD_FILTERED_EVENT_BITS & bit) != 0) == JvmtiUtil::event_threaded(ei),
 906            "thread filtered event list does not match");
 907   }
 908 #endif
 909 
 910   _initialized = true;
 911 }
 912 
 913 void
 914 JvmtiEventControllerPrivate::vm_start() {
 915   // some events are now able to be enabled (phase has changed)
 916   JvmtiEventControllerPrivate::recompute_enabled();
 917 }
 918 
 919 
 920 void
 921 JvmtiEventControllerPrivate::vm_init() {
 922   event_init();
 923 
 924   // all the events are now able to be enabled (phase has changed)
 925   JvmtiEventControllerPrivate::recompute_enabled();
 926 }
 927 
 928 
 929 void
 930 JvmtiEventControllerPrivate::vm_death() {
 931   // events are disabled (phase has changed)
 932   JvmtiEventControllerPrivate::recompute_enabled();
 933 }
 934 
 935 
 936 ///////////////////////////////////////////////////////////////
 937 //
 938 // JvmtiEventController
 939 //
 940 
 941 JvmtiEventEnabled JvmtiEventController::_universal_global_event_enabled;
 942 
 943 bool
 944 JvmtiEventController::is_global_event(jvmtiEvent event_type) {
 945   assert(is_valid_event_type(event_type), "invalid event type");
 946   jlong bit_for = ((jlong)1) << (event_type - TOTAL_MIN_EVENT_TYPE_VAL);
 947   return((bit_for & GLOBAL_EVENT_BITS)!=0);
 948 }
 949 
 950 void
 951 JvmtiEventController::set_user_enabled(JvmtiEnvBase *env, JavaThread *thread, jvmtiEvent event_type, bool enabled) {
 952   if (Threads::number_of_threads() == 0) {
 953     // during early VM start-up locks don't exist, but we are safely single threaded,
 954     // call the functionality without holding the JvmtiThreadState_lock.
 955     JvmtiEventControllerPrivate::set_user_enabled(env, thread, event_type, enabled);
 956   } else {
 957     MutexLocker mu(JvmtiThreadState_lock);
 958     JvmtiEventControllerPrivate::set_user_enabled(env, thread, event_type, enabled);
 959   }
 960 }
 961 
 962 
 963 void
 964 JvmtiEventController::set_event_callbacks(JvmtiEnvBase *env,
 965                                           const jvmtiEventCallbacks* callbacks,
 966                                           jint size_of_callbacks) {
 967   if (Threads::number_of_threads() == 0) {
 968     // during early VM start-up locks don't exist, but we are safely single threaded,
 969     // call the functionality without holding the JvmtiThreadState_lock.
 970     JvmtiEventControllerPrivate::set_event_callbacks(env, callbacks, size_of_callbacks);
 971   } else {
 972     MutexLocker mu(JvmtiThreadState_lock);
 973     JvmtiEventControllerPrivate::set_event_callbacks(env, callbacks, size_of_callbacks);
 974   }
 975 }
 976 
 977 void
 978 JvmtiEventController::set_extension_event_callback(JvmtiEnvBase *env,
 979                                                    jint extension_event_index,
 980                                                    jvmtiExtensionEvent callback) {
 981   if (Threads::number_of_threads() == 0) {
 982     JvmtiEventControllerPrivate::set_extension_event_callback(env, extension_event_index, callback);
 983   } else {
 984     MutexLocker mu(JvmtiThreadState_lock);
 985     JvmtiEventControllerPrivate::set_extension_event_callback(env, extension_event_index, callback);
 986   }
 987 }
 988 
 989 
 990 
 991 
 992 void
 993 JvmtiEventController::set_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
 994   MutexLockerEx mu(SafepointSynchronize::is_at_safepoint() ? NULL : JvmtiThreadState_lock);
 995   JvmtiEventControllerPrivate::set_frame_pop(ets, fpop);
 996 }
 997 
 998 
 999 void
1000 JvmtiEventController::clear_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
1001   MutexLockerEx mu(SafepointSynchronize::is_at_safepoint() ? NULL : JvmtiThreadState_lock);
1002   JvmtiEventControllerPrivate::clear_frame_pop(ets, fpop);
1003 }
1004 
1005 
1006 void
1007 JvmtiEventController::clear_to_frame_pop(JvmtiEnvThreadState *ets, JvmtiFramePop fpop) {
1008   MutexLockerEx mu(SafepointSynchronize::is_at_safepoint() ? NULL : JvmtiThreadState_lock);
1009   JvmtiEventControllerPrivate::clear_to_frame_pop(ets, fpop);
1010 }
1011 
1012 void
1013 JvmtiEventController::change_field_watch(jvmtiEvent event_type, bool added) {
1014   MutexLocker mu(JvmtiThreadState_lock);
1015   JvmtiEventControllerPrivate::change_field_watch(event_type, added);
1016 }
1017 
1018 void
1019 JvmtiEventController::thread_started(JavaThread *thread) {
1020   // operates only on the current thread
1021   // JvmtiThreadState_lock grabbed only if needed.
1022   JvmtiEventControllerPrivate::thread_started(thread);
1023 }
1024 
1025 void
1026 JvmtiEventController::thread_ended(JavaThread *thread) {
1027   // operates only on the current thread
1028   // JvmtiThreadState_lock grabbed only if needed.
1029   JvmtiEventControllerPrivate::thread_ended(thread);
1030 }
1031 
1032 void
1033 JvmtiEventController::env_initialize(JvmtiEnvBase *env) {
1034   if (Threads::number_of_threads() == 0) {
1035     // during early VM start-up locks don't exist, but we are safely single threaded,
1036     // call the functionality without holding the JvmtiThreadState_lock.
1037     JvmtiEventControllerPrivate::env_initialize(env);
1038   } else {
1039     MutexLocker mu(JvmtiThreadState_lock);
1040     JvmtiEventControllerPrivate::env_initialize(env);
1041   }
1042 }
1043 
1044 void
1045 JvmtiEventController::env_dispose(JvmtiEnvBase *env) {
1046   if (Threads::number_of_threads() == 0) {
1047     // during early VM start-up locks don't exist, but we are safely single threaded,
1048     // call the functionality without holding the JvmtiThreadState_lock.
1049     JvmtiEventControllerPrivate::env_dispose(env);
1050   } else {
1051     MutexLocker mu(JvmtiThreadState_lock);
1052     JvmtiEventControllerPrivate::env_dispose(env);
1053   }
1054 }
1055 
1056 
1057 void
1058 JvmtiEventController::vm_start() {
1059   if (JvmtiEnvBase::environments_might_exist()) {
1060     MutexLocker mu(JvmtiThreadState_lock);
1061     JvmtiEventControllerPrivate::vm_start();
1062   }
1063 }
1064 
1065 void
1066 JvmtiEventController::vm_init() {
1067   if (JvmtiEnvBase::environments_might_exist()) {
1068     MutexLocker mu(JvmtiThreadState_lock);
1069     JvmtiEventControllerPrivate::vm_init();
1070   }
1071 }
1072 
1073 void
1074 JvmtiEventController::vm_death() {
1075   if (JvmtiEnvBase::environments_might_exist()) {
1076     MutexLocker mu(JvmtiThreadState_lock);
1077     JvmtiEventControllerPrivate::vm_death();
1078   }
1079 }