1 /*
   2  * Copyright (c) 1998, 2019, 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 #ifndef SHARE_PRIMS_JVMTIEXPORT_HPP
  26 #define SHARE_PRIMS_JVMTIEXPORT_HPP
  27 
  28 #include "jvmtifiles/jvmti.h"
  29 #include "memory/allocation.hpp"
  30 #include "memory/iterator.hpp"
  31 #include "oops/oop.hpp"
  32 #include "oops/oopsHierarchy.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/handles.hpp"
  35 #include "utilities/globalDefinitions.hpp"
  36 #include "utilities/growableArray.hpp"
  37 #include "utilities/macros.hpp"
  38 
  39 // Must be included after jvmti.h.
  40 #include "jvmticmlr.h"
  41 
  42 // Forward declarations
  43 
  44 class JvmtiEventControllerPrivate;
  45 class JvmtiManageCapabilities;
  46 class JvmtiEnv;
  47 class JvmtiThreadState;
  48 
  49 #define JVMTI_SUPPORT_FLAG(key)                                           \
  50   private:                                                                \
  51   static bool  _##key;                                                    \
  52   public:                                                                 \
  53   inline static void set_##key(bool on) {                                 \
  54     JVMTI_ONLY(_##key = (on != 0));                                       \
  55     NOT_JVMTI(report_unsupported(on));                                    \
  56   }                                                                       \
  57   inline static bool key() {                                              \
  58     JVMTI_ONLY(return _##key);                                            \
  59     NOT_JVMTI(return false);                                              \
  60   }
  61 
  62 
  63 // This class contains the JVMTI interface for the rest of hotspot.
  64 //
  65 class JvmtiExport : public AllStatic {
  66   friend class VMStructs;
  67   friend class CompileReplay;
  68 
  69  private:
  70 
  71 #if INCLUDE_JVMTI
  72   static int         _field_access_count;
  73   static int         _field_modification_count;
  74 
  75   static bool        _can_access_local_variables;
  76   static bool        _can_hotswap_or_post_breakpoint;
  77   static bool        _can_modify_any_class;
  78   static bool        _can_walk_any_space;
  79 #endif // INCLUDE_JVMTI
  80 
  81   JVMTI_SUPPORT_FLAG(can_get_source_debug_extension)
  82   JVMTI_SUPPORT_FLAG(can_maintain_original_method_order)
  83   JVMTI_SUPPORT_FLAG(can_post_interpreter_events)
  84   JVMTI_SUPPORT_FLAG(can_post_on_exceptions)
  85   JVMTI_SUPPORT_FLAG(can_post_breakpoint)
  86   JVMTI_SUPPORT_FLAG(can_post_field_access)
  87   JVMTI_SUPPORT_FLAG(can_post_field_modification)
  88   JVMTI_SUPPORT_FLAG(can_post_method_entry)
  89   JVMTI_SUPPORT_FLAG(can_post_method_exit)
  90   JVMTI_SUPPORT_FLAG(can_post_frame_pop)
  91   JVMTI_SUPPORT_FLAG(can_pop_frame)
  92   JVMTI_SUPPORT_FLAG(can_force_early_return)
  93   JVMTI_SUPPORT_FLAG(can_support_fibers)
  94   JVMTI_SUPPORT_FLAG(can_support_continuations)
  95 
  96   JVMTI_SUPPORT_FLAG(early_vmstart_recorded)
  97 
  98   friend class JvmtiEventControllerPrivate;  // should only modify these flags
  99   JVMTI_SUPPORT_FLAG(should_post_single_step)
 100   JVMTI_SUPPORT_FLAG(should_post_field_access)
 101   JVMTI_SUPPORT_FLAG(should_post_field_modification)
 102   JVMTI_SUPPORT_FLAG(should_post_class_load)
 103   JVMTI_SUPPORT_FLAG(should_post_class_prepare)
 104   JVMTI_SUPPORT_FLAG(should_post_class_unload)
 105   JVMTI_SUPPORT_FLAG(should_post_native_method_bind)
 106   JVMTI_SUPPORT_FLAG(should_post_compiled_method_load)
 107   JVMTI_SUPPORT_FLAG(should_post_compiled_method_unload)
 108   JVMTI_SUPPORT_FLAG(should_post_dynamic_code_generated)
 109   JVMTI_SUPPORT_FLAG(should_post_monitor_contended_enter)
 110   JVMTI_SUPPORT_FLAG(should_post_monitor_contended_entered)
 111   JVMTI_SUPPORT_FLAG(should_post_monitor_wait)
 112   JVMTI_SUPPORT_FLAG(should_post_monitor_waited)
 113   JVMTI_SUPPORT_FLAG(should_post_data_dump)
 114   JVMTI_SUPPORT_FLAG(should_post_garbage_collection_start)
 115   JVMTI_SUPPORT_FLAG(should_post_garbage_collection_finish)
 116   JVMTI_SUPPORT_FLAG(should_post_on_exceptions)
 117 
 118   // ------ the below maybe don't have to be (but are for now)
 119   // fixed conditions here ------------
 120   // any events can be enabled
 121   JVMTI_SUPPORT_FLAG(should_post_thread_life)
 122   JVMTI_SUPPORT_FLAG(should_post_object_free)
 123   JVMTI_SUPPORT_FLAG(should_post_resource_exhausted)
 124 
 125   // we are holding objects on the heap - need to talk to GC - e.g.
 126   // breakpoint info
 127   JVMTI_SUPPORT_FLAG(should_clean_up_heap_objects)
 128   JVMTI_SUPPORT_FLAG(should_post_vm_object_alloc)
 129   JVMTI_SUPPORT_FLAG(should_post_sampled_object_alloc)
 130 
 131   JVMTI_SUPPORT_FLAG(should_post_continuation_run)
 132   JVMTI_SUPPORT_FLAG(should_post_continuation_yield)
 133 
 134   JVMTI_SUPPORT_FLAG(should_post_fiber_scheduled)
 135   JVMTI_SUPPORT_FLAG(should_post_fiber_terminated)
 136   JVMTI_SUPPORT_FLAG(should_post_fiber_mount)
 137   JVMTI_SUPPORT_FLAG(should_post_fiber_unmount)
 138 
 139   // If flag cannot be implemented, give an error if on=true
 140   static void report_unsupported(bool on);
 141 
 142   // these should only be called by the friend class
 143   friend class JvmtiManageCapabilities;
 144   inline static void set_can_modify_any_class(bool on) {
 145     JVMTI_ONLY(_can_modify_any_class = (on != 0);)
 146   }
 147   inline static void set_can_access_local_variables(bool on) {
 148     JVMTI_ONLY(_can_access_local_variables = (on != 0);)
 149   }
 150   inline static void set_can_hotswap_or_post_breakpoint(bool on) {
 151     JVMTI_ONLY(_can_hotswap_or_post_breakpoint = (on != 0);)
 152   }
 153   inline static void set_can_walk_any_space(bool on) {
 154     JVMTI_ONLY(_can_walk_any_space = (on != 0);)
 155   }
 156 
 157   enum {
 158     JVMTI_VERSION_MASK   = 0x70000000,
 159     JVMTI_VERSION_VALUE  = 0x30000000,
 160     JVMDI_VERSION_VALUE  = 0x20000000
 161   };
 162 
 163   static void post_field_modification(JavaThread *thread, Method* method, address location,
 164                                       Klass* field_klass, Handle object, jfieldID field,
 165                                       char sig_type, jvalue *value);
 166 
 167 
 168   // posts a DynamicCodeGenerated event (internal/private implementation).
 169   // The public post_dynamic_code_generated* functions make use of the
 170   // internal implementation.  Also called from JvmtiDeferredEvent::post()
 171   static void post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
 172 
 173  private:
 174 
 175   // GenerateEvents support to allow posting of CompiledMethodLoad and
 176   // DynamicCodeGenerated events for a given environment.
 177   friend class JvmtiCodeBlobEvents;
 178 
 179   static void post_compiled_method_load(JvmtiEnv* env, nmethod *nm) NOT_JVMTI_RETURN;
 180   static void post_dynamic_code_generated(JvmtiEnv* env, const char *name, const void *code_begin,
 181                                           const void *code_end) NOT_JVMTI_RETURN;
 182 
 183   // This flag indicates whether RedefineClasses() has ever redefined
 184   // one or more classes during the lifetime of the VM. The flag should
 185   // only be set by the friend class and can be queried by other sub
 186   // systems as needed to relax invariant checks.
 187   static bool _has_redefined_a_class;
 188   friend class VM_RedefineClasses;
 189   inline static void set_has_redefined_a_class() {
 190     JVMTI_ONLY(_has_redefined_a_class = true;)
 191   }
 192   // Flag to indicate if the compiler has recorded all dependencies. When the
 193   // can_redefine_classes capability is enabled in the OnLoad phase then the compiler
 194   // records all dependencies from startup. However if the capability is first
 195   // enabled some time later then the dependencies recorded by the compiler
 196   // are incomplete. This flag is used by RedefineClasses to know if the
 197   // dependency information is complete or not.
 198   static bool _all_dependencies_are_recorded;
 199 
 200  public:
 201   inline static bool has_redefined_a_class() {
 202     JVMTI_ONLY(return _has_redefined_a_class);
 203     NOT_JVMTI(return false);
 204   }
 205 
 206   inline static bool all_dependencies_are_recorded() {
 207     return _all_dependencies_are_recorded;
 208   }
 209 
 210   inline static void set_all_dependencies_are_recorded(bool on) {
 211     _all_dependencies_are_recorded = (on != 0);
 212   }
 213 
 214   // Add read edges to the unnamed modules of the bootstrap and app class loaders
 215   static void add_default_read_edges(Handle h_module, TRAPS) NOT_JVMTI_RETURN;
 216 
 217   // Add a read edge to the module
 218   static jvmtiError add_module_reads(Handle module, Handle to_module, TRAPS);
 219 
 220   // Updates a module to export a package
 221   static jvmtiError add_module_exports(Handle module, Handle pkg_name, Handle to_module, TRAPS);
 222 
 223   // Updates a module to open a package
 224   static jvmtiError add_module_opens(Handle module, Handle pkg_name, Handle to_module, TRAPS);
 225 
 226   // Add a used service to the module
 227   static jvmtiError add_module_uses(Handle module, Handle service, TRAPS);
 228 
 229   // Add a service provider to the module
 230   static jvmtiError add_module_provides(Handle module, Handle service, Handle impl_class, TRAPS);
 231 
 232   // let JVMTI know that the JVM_OnLoad code is running
 233   static void enter_onload_phase() NOT_JVMTI_RETURN;
 234 
 235   // let JVMTI know that the VM isn't up yet (and JVM_OnLoad code isn't running)
 236   static void enter_primordial_phase() NOT_JVMTI_RETURN;
 237 
 238   // let JVMTI know that the VM isn't up yet but JNI is live
 239   static void enter_early_start_phase() NOT_JVMTI_RETURN;
 240   static void enter_start_phase() NOT_JVMTI_RETURN;
 241 
 242   // let JVMTI know that the VM is fully up and running now
 243   static void enter_live_phase() NOT_JVMTI_RETURN;
 244 
 245   // ------ can_* conditions (below) are set at OnLoad and never changed ------------
 246   inline static bool can_modify_any_class()                       {
 247     JVMTI_ONLY(return _can_modify_any_class);
 248     NOT_JVMTI(return false);
 249   }
 250   inline static bool can_access_local_variables()                 {
 251     JVMTI_ONLY(return _can_access_local_variables);
 252     NOT_JVMTI(return false);
 253   }
 254   inline static bool can_hotswap_or_post_breakpoint()             {
 255     JVMTI_ONLY(return _can_hotswap_or_post_breakpoint);
 256     NOT_JVMTI(return false);
 257   }
 258   inline static bool can_walk_any_space()                         {
 259     JVMTI_ONLY(return _can_walk_any_space);
 260     NOT_JVMTI(return false);
 261   }
 262 
 263   // field access management
 264   static address  get_field_access_count_addr() NOT_JVMTI_RETURN_(0);
 265 
 266   // field modification management
 267   static address  get_field_modification_count_addr() NOT_JVMTI_RETURN_(0);
 268 
 269   // -----------------
 270 
 271   static bool is_jvmti_version(jint version)                      {
 272     JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMTI_VERSION_VALUE);
 273     NOT_JVMTI(return false);
 274   }
 275   static bool is_jvmdi_version(jint version)                      {
 276     JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMDI_VERSION_VALUE);
 277     NOT_JVMTI(return false);
 278   }
 279   static jint get_jvmti_interface(JavaVM *jvm, void **penv, jint version) NOT_JVMTI_RETURN_(0);
 280   static void decode_version_values(jint version, int * major, int * minor,
 281                                     int * micro) NOT_JVMTI_RETURN;
 282 
 283   // single stepping management methods
 284   static void at_single_stepping_point(JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
 285   static void expose_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN;
 286   static bool hide_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN_(false);
 287 
 288   // Methods that notify the debugger that something interesting has happened in the VM.
 289   static void post_early_vm_start        () NOT_JVMTI_RETURN;
 290   static void post_vm_start              () NOT_JVMTI_RETURN;
 291   static void post_vm_initialized        () NOT_JVMTI_RETURN;
 292   static void post_vm_death              () NOT_JVMTI_RETURN;
 293 
 294   static void post_single_step           (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
 295   static void post_raw_breakpoint        (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
 296 
 297   static void post_exception_throw       (JavaThread *thread, Method* method, address location, oop exception) NOT_JVMTI_RETURN;
 298   static void notice_unwind_due_to_exception (JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) NOT_JVMTI_RETURN;
 299 
 300   static oop jni_GetField_probe          (JavaThread *thread, jobject jobj,
 301     oop obj, Klass* klass, jfieldID fieldID, bool is_static)
 302     NOT_JVMTI_RETURN_(NULL);
 303   static oop jni_GetField_probe_nh       (JavaThread *thread, jobject jobj,
 304     oop obj, Klass* klass, jfieldID fieldID, bool is_static)
 305     NOT_JVMTI_RETURN_(NULL);
 306   static void post_field_access_by_jni   (JavaThread *thread, oop obj,
 307     Klass* klass, jfieldID fieldID, bool is_static) NOT_JVMTI_RETURN;
 308   static void post_field_access          (JavaThread *thread, Method* method,
 309     address location, Klass* field_klass, Handle object, jfieldID field) NOT_JVMTI_RETURN;
 310   static oop jni_SetField_probe          (JavaThread *thread, jobject jobj,
 311     oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
 312     jvalue *value) NOT_JVMTI_RETURN_(NULL);
 313   static oop jni_SetField_probe_nh       (JavaThread *thread, jobject jobj,
 314     oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
 315     jvalue *value) NOT_JVMTI_RETURN_(NULL);
 316   static void post_field_modification_by_jni(JavaThread *thread, oop obj,
 317     Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
 318     jvalue *value);
 319   static void post_raw_field_modification(JavaThread *thread, Method* method,
 320     address location, Klass* field_klass, Handle object, jfieldID field,
 321     char sig_type, jvalue *value) NOT_JVMTI_RETURN;
 322 
 323   static void post_method_entry          (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
 324   static void post_method_exit           (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
 325 
 326   static void post_class_load            (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
 327   static void post_class_unload          (Klass* klass) NOT_JVMTI_RETURN;
 328   static void post_class_prepare         (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
 329 
 330   static void post_thread_start          (JavaThread *thread) NOT_JVMTI_RETURN;
 331   static void post_thread_end            (JavaThread *thread) NOT_JVMTI_RETURN;
 332 
 333   static void post_fiber_scheduled       (jthread thread, jobject fiber) NOT_JVMTI_RETURN;
 334   static void post_fiber_terminated      (jthread thread, jobject fiber) NOT_JVMTI_RETURN;
 335   static void post_fiber_mount           (jthread thread, jobject fiber) NOT_JVMTI_RETURN;
 336   static void post_fiber_unmount         (jthread thread, jobject fiber) NOT_JVMTI_RETURN;
 337   
 338   static void post_continuation_run      (JavaThread* thread, jint continuation_frame_count) NOT_JVMTI_RETURN;
 339   static void post_continuation_yield    (JavaThread* thread, jint continuation_frame_count) NOT_JVMTI_RETURN;
 340 
 341   // Support for java.lang.instrument agent loading.
 342   static bool _should_post_class_file_load_hook;
 343   inline static void set_should_post_class_file_load_hook(bool on)     { _should_post_class_file_load_hook = on;  }
 344   inline static bool should_post_class_file_load_hook()           {
 345     JVMTI_ONLY(return _should_post_class_file_load_hook);
 346     NOT_JVMTI(return false;)
 347   }
 348   static bool is_early_phase() NOT_JVMTI_RETURN_(false);
 349   static bool has_early_class_hook_env() NOT_JVMTI_RETURN_(false);
 350   // Return true if the class was modified by the hook.
 351   static bool post_class_file_load_hook(Symbol* h_name, Handle class_loader,
 352                                         Handle h_protection_domain,
 353                                         unsigned char **data_ptr, unsigned char **end_ptr,
 354                                         JvmtiCachedClassFileData **cache_ptr) NOT_JVMTI_RETURN_(false);
 355   static void post_native_method_bind(Method* method, address* function_ptr) NOT_JVMTI_RETURN;
 356   static void post_compiled_method_load(nmethod *nm) NOT_JVMTI_RETURN;
 357   static void post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
 358 
 359   // used to post a CompiledMethodUnload event
 360   static void post_compiled_method_unload(jmethodID mid, const void *code_begin) NOT_JVMTI_RETURN;
 361 
 362   // similiar to post_dynamic_code_generated except that it can be used to
 363   // post a DynamicCodeGenerated event while holding locks in the VM. Any event
 364   // posted using this function is recorded by the enclosing event collector
 365   // -- JvmtiDynamicCodeEventCollector.
 366   static void post_dynamic_code_generated_while_holding_locks(const char* name, address code_begin, address code_end) NOT_JVMTI_RETURN;
 367 
 368   static void post_garbage_collection_finish() NOT_JVMTI_RETURN;
 369   static void post_garbage_collection_start() NOT_JVMTI_RETURN;
 370   static void post_data_dump() NOT_JVMTI_RETURN;
 371   static void post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
 372   static void post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
 373   static void post_monitor_wait(JavaThread *thread, oop obj, jlong timeout) NOT_JVMTI_RETURN;
 374   static void post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) NOT_JVMTI_RETURN;
 375   static void post_object_free(JvmtiEnv* env, jlong tag) NOT_JVMTI_RETURN;
 376   static void post_resource_exhausted(jint resource_exhausted_flags, const char* detail) NOT_JVMTI_RETURN;
 377   static void record_vm_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
 378   // Post objects collected by vm_object_alloc_event_collector.
 379   static void post_vm_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
 380   // Collects vm internal objects for later event posting.
 381   inline static void vm_object_alloc_event_collector(oop object) {
 382     if (should_post_vm_object_alloc()) {
 383       record_vm_internal_object_allocation(object);
 384     }
 385   }
 386 
 387   static void record_sampled_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
 388   // Post objects collected by sampled_object_alloc_event_collector.
 389   static void post_sampled_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
 390 
 391   // Collects vm internal objects for later event posting.
 392   inline static void sampled_object_alloc_event_collector(oop object) {
 393     if (should_post_sampled_object_alloc()) {
 394       record_sampled_internal_object_allocation(object);
 395     }
 396   }
 397 
 398   inline static void post_array_size_exhausted() {
 399     if (should_post_resource_exhausted()) {
 400       post_resource_exhausted(JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
 401                               "Requested array size exceeds VM limit");
 402     }
 403   }
 404 
 405   static void cleanup_thread             (JavaThread* thread) NOT_JVMTI_RETURN;
 406   static void clear_detected_exception   (JavaThread* thread) NOT_JVMTI_RETURN;
 407 
 408   static void oops_do(OopClosure* f) NOT_JVMTI_RETURN;
 409   static void weak_oops_do(BoolObjectClosure* b, OopClosure* f) NOT_JVMTI_RETURN;
 410 
 411   static void transition_pending_onload_raw_monitors() NOT_JVMTI_RETURN;
 412 
 413 #if INCLUDE_SERVICES
 414   // attach support
 415   static jint load_agent_library(const char *agent, const char *absParam, const char *options, outputStream* out) NOT_JVMTI_RETURN_(JNI_ERR);
 416 #endif
 417 
 418   // SetNativeMethodPrefix support
 419   static char** get_all_native_method_prefixes(int* count_ptr) NOT_JVMTI_RETURN_(NULL);
 420 
 421   // JavaThread lifecycle support:
 422   static jvmtiError cv_external_thread_to_JavaThread(ThreadsList * t_list,
 423                                                      jthread thread,
 424                                                      JavaThread ** jt_pp,
 425                                                      oop * thread_oop_p);
 426   static jvmtiError cv_oop_to_JavaThread(ThreadsList * t_list, oop thread_oop,
 427                                          JavaThread ** jt_pp);
 428 };
 429 
 430 // Support class used by JvmtiDynamicCodeEventCollector and others. It
 431 // describes a single code blob by name and address range.
 432 class JvmtiCodeBlobDesc : public CHeapObj<mtInternal> {
 433  private:
 434   char _name[64];
 435   address _code_begin;
 436   address _code_end;
 437 
 438  public:
 439   JvmtiCodeBlobDesc(const char *name, address code_begin, address code_end) {
 440     assert(name != NULL, "all code blobs must be named");
 441     strncpy(_name, name, sizeof(_name) - 1);
 442     _name[sizeof(_name)-1] = '\0';
 443     _code_begin = code_begin;
 444     _code_end = code_end;
 445   }
 446   char* name()                  { return _name; }
 447   address code_begin()          { return _code_begin; }
 448   address code_end()            { return _code_end; }
 449 };
 450 
 451 // JvmtiEventCollector is a helper class to setup thread for
 452 // event collection.
 453 class JvmtiEventCollector : public StackObj {
 454  private:
 455   JvmtiEventCollector* _prev;  // Save previous one to support nested event collector.
 456   bool _unset_jvmti_thread_state;
 457 
 458  public:
 459   JvmtiEventCollector() : _prev(NULL), _unset_jvmti_thread_state(false) {}
 460 
 461   void setup_jvmti_thread_state(); // Set this collector in current thread, returns if success.
 462   void unset_jvmti_thread_state(); // Reset previous collector in current thread.
 463   virtual bool is_dynamic_code_event()   { return false; }
 464   virtual bool is_vm_object_alloc_event(){ return false; }
 465   virtual bool is_sampled_object_alloc_event(){ return false; }
 466   JvmtiEventCollector *get_prev()        { return _prev; }
 467 };
 468 
 469 // A JvmtiDynamicCodeEventCollector is a helper class for the JvmtiExport
 470 // interface. It collects "dynamic code generated" events that are posted
 471 // while holding locks. When the event collector goes out of scope the
 472 // events will be posted.
 473 //
 474 // Usage :-
 475 //
 476 // {
 477 //   JvmtiDynamicCodeEventCollector event_collector;
 478 //   :
 479 //   { MutexLocker ml(...)
 480 //     :
 481 //     JvmtiExport::post_dynamic_code_generated_while_holding_locks(...)
 482 //   }
 483 //   // event collector goes out of scope => post events to profiler.
 484 // }
 485 
 486 class JvmtiDynamicCodeEventCollector : public JvmtiEventCollector {
 487  private:
 488   GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs;           // collected code blob events
 489 
 490   friend class JvmtiExport;
 491   void register_stub(const char* name, address start, address end);
 492 
 493  public:
 494   JvmtiDynamicCodeEventCollector()  NOT_JVMTI_RETURN;
 495   ~JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN;
 496   bool is_dynamic_code_event()   { return true; }
 497 
 498 };
 499 
 500 // Used as a base class for object allocation collection and then posting
 501 // the allocations to any event notification callbacks.
 502 //
 503 class JvmtiObjectAllocEventCollector : public JvmtiEventCollector {
 504  protected:
 505   GrowableArray<oop>* _allocated;      // field to record collected allocated object oop.
 506   bool _enable;                   // This flag is enabled in constructor if set up in the thread state
 507                                   // and disabled in destructor before posting event. To avoid
 508                                   // collection of objects allocated while running java code inside
 509                                   // agent post_X_object_alloc() event handler.
 510   void (*_post_callback)(JavaThread*, oop); // what callback to use when destroying the collector.
 511 
 512   //GC support
 513   void oops_do(OopClosure* f);
 514 
 515   friend class JvmtiExport;
 516 
 517   // Record allocated object oop.
 518   inline void record_allocation(oop obj);
 519 
 520   //GC support
 521   static void oops_do_for_all_threads(OopClosure* f);
 522 
 523  public:
 524   JvmtiObjectAllocEventCollector()  NOT_JVMTI_RETURN;
 525 
 526   void generate_call_for_allocated();
 527 
 528   bool is_enabled()                 { return _enable; }
 529   void set_enabled(bool on)         { _enable = on; }
 530 };
 531 
 532 // Used to record vm internally allocated object oops and post
 533 // vm object alloc event for objects visible to java world.
 534 // Constructor enables JvmtiThreadState flag and all vm allocated
 535 // objects are recorded in a growable array. When destructor is
 536 // called the vm object alloc event is posted for each object
 537 // visible to java world.
 538 // See jvm.cpp file for its usage.
 539 //
 540 class JvmtiVMObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
 541  public:
 542   JvmtiVMObjectAllocEventCollector()  NOT_JVMTI_RETURN;
 543   ~JvmtiVMObjectAllocEventCollector()  NOT_JVMTI_RETURN;
 544   virtual bool is_vm_object_alloc_event()   { return true; }
 545 };
 546 
 547 // Used to record sampled allocated object oops and post
 548 // sampled object alloc event.
 549 // Constructor enables JvmtiThreadState flag and all sampled allocated
 550 // objects are recorded in a growable array. When destructor is
 551 // called the sampled object alloc event is posted for each sampled object.
 552 // See jvm.cpp file for its usage.
 553 //
 554 class JvmtiSampledObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
 555  public:
 556   JvmtiSampledObjectAllocEventCollector()  NOT_JVMTI_RETURN;
 557   ~JvmtiSampledObjectAllocEventCollector()  NOT_JVMTI_RETURN;
 558   bool is_sampled_object_alloc_event()    { return true; }
 559   static bool object_alloc_is_safe_to_sample() NOT_JVMTI_RETURN_(false);
 560 };
 561 
 562 // Marker class to disable the posting of VMObjectAlloc events
 563 // within its scope.
 564 //
 565 // Usage :-
 566 //
 567 // {
 568 //   NoJvmtiVMObjectAllocMark njm;
 569 //   :
 570 //   // VMObjAlloc event will not be posted
 571 //   JvmtiExport::vm_object_alloc_event_collector(obj);
 572 //   :
 573 // }
 574 
 575 class NoJvmtiVMObjectAllocMark : public StackObj {
 576  private:
 577   // enclosing collector if enabled, NULL otherwise
 578   JvmtiVMObjectAllocEventCollector *_collector;
 579 
 580   bool was_enabled()    { return _collector != NULL; }
 581 
 582  public:
 583   NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
 584   ~NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
 585 };
 586 
 587 
 588 // Base class for reporting GC events to JVMTI.
 589 class JvmtiGCMarker : public StackObj {
 590  public:
 591   JvmtiGCMarker() NOT_JVMTI_RETURN;
 592   ~JvmtiGCMarker() NOT_JVMTI_RETURN;
 593 };
 594 
 595 // JvmtiHideSingleStepping is a helper class for hiding
 596 // internal single step events.
 597 class JvmtiHideSingleStepping : public StackObj {
 598  private:
 599   bool         _single_step_hidden;
 600   JavaThread * _thread;
 601 
 602  public:
 603   JvmtiHideSingleStepping(JavaThread * thread) {
 604     assert(thread != NULL, "sanity check");
 605 
 606     _single_step_hidden = false;
 607     _thread = thread;
 608     if (JvmtiExport::should_post_single_step()) {
 609       _single_step_hidden = JvmtiExport::hide_single_stepping(_thread);
 610     }
 611   }
 612 
 613   ~JvmtiHideSingleStepping() {
 614     if (_single_step_hidden) {
 615       JvmtiExport::expose_single_stepping(_thread);
 616     }
 617   }
 618 };
 619 
 620 #endif // SHARE_PRIMS_JVMTIEXPORT_HPP