1 /*
  2  * Copyright (c) 1998, 2021, 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/oopHandle.hpp"
 33 #include "oops/oopsHierarchy.hpp"
 34 #include "runtime/frame.hpp"
 35 #include "runtime/handles.hpp"
 36 #include "utilities/globalDefinitions.hpp"
 37 #include "utilities/growableArray.hpp"
 38 #include "utilities/macros.hpp"
 39 
 40 // Must be included after jvmti.h.
 41 #include "jvmticmlr.h"
 42 
 43 // Forward declarations
 44 
 45 struct JvmtiCachedClassFileData;
 46 class JvmtiEventControllerPrivate;
 47 class JvmtiManageCapabilities;
 48 class JvmtiEnv;
 49 class JvmtiThreadState;
 50 
 51 class OopStorage;
 52 
 53 #define JVMTI_SUPPORT_FLAG(key)                                           \
 54   private:                                                                \
 55   static bool  _##key;                                                    \
 56   public:                                                                 \
 57   inline static void set_##key(bool on) {                                 \
 58     JVMTI_ONLY(_##key = (on != 0));                                       \
 59     NOT_JVMTI(report_unsupported(on));                                    \
 60   }                                                                       \
 61   inline static bool key() {                                              \
 62     JVMTI_ONLY(return _##key);                                            \
 63     NOT_JVMTI(return false);                                              \
 64   }
 65 
 66 
 67 // This class contains the JVMTI interface for the rest of hotspot.
 68 //
 69 class JvmtiExport : public AllStatic {
 70   friend class VMStructs;
 71   friend class CompileReplay;
 72 
 73  private:
 74 
 75 #if INCLUDE_JVMTI
 76   static int         _field_access_count;
 77   static int         _field_modification_count;
 78 
 79   static bool        _can_access_local_variables;
 80   static bool        _can_hotswap_or_post_breakpoint;
 81   static bool        _can_modify_any_class;
 82   static bool        _can_walk_any_space;
 83 #endif // INCLUDE_JVMTI
 84 
 85   JVMTI_SUPPORT_FLAG(can_get_source_debug_extension)
 86   JVMTI_SUPPORT_FLAG(can_maintain_original_method_order)
 87   JVMTI_SUPPORT_FLAG(can_post_interpreter_events)
 88   JVMTI_SUPPORT_FLAG(can_post_on_exceptions)
 89   JVMTI_SUPPORT_FLAG(can_post_breakpoint)
 90   JVMTI_SUPPORT_FLAG(can_post_field_access)
 91   JVMTI_SUPPORT_FLAG(can_post_field_modification)
 92   JVMTI_SUPPORT_FLAG(can_post_method_entry)
 93   JVMTI_SUPPORT_FLAG(can_post_method_exit)
 94   JVMTI_SUPPORT_FLAG(can_post_frame_pop)
 95   JVMTI_SUPPORT_FLAG(can_pop_frame)
 96   JVMTI_SUPPORT_FLAG(can_force_early_return)
 97   JVMTI_SUPPORT_FLAG(can_support_virtual_threads)
 98 
 99   JVMTI_SUPPORT_FLAG(early_vmstart_recorded)
100   JVMTI_SUPPORT_FLAG(can_get_owned_monitor_info) // includes can_get_owned_monitor_stack_depth_info
101 
102   friend class JvmtiEventControllerPrivate;  // should only modify these flags
103   JVMTI_SUPPORT_FLAG(should_post_single_step)
104   JVMTI_SUPPORT_FLAG(should_post_field_access)
105   JVMTI_SUPPORT_FLAG(should_post_field_modification)
106   JVMTI_SUPPORT_FLAG(should_post_class_load)
107   JVMTI_SUPPORT_FLAG(should_post_class_prepare)
108   JVMTI_SUPPORT_FLAG(should_post_class_unload)
109   JVMTI_SUPPORT_FLAG(should_post_native_method_bind)
110   JVMTI_SUPPORT_FLAG(should_post_compiled_method_load)
111   JVMTI_SUPPORT_FLAG(should_post_compiled_method_unload)
112   JVMTI_SUPPORT_FLAG(should_post_dynamic_code_generated)
113   JVMTI_SUPPORT_FLAG(should_post_monitor_contended_enter)
114   JVMTI_SUPPORT_FLAG(should_post_monitor_contended_entered)
115   JVMTI_SUPPORT_FLAG(should_post_monitor_wait)
116   JVMTI_SUPPORT_FLAG(should_post_monitor_waited)
117   JVMTI_SUPPORT_FLAG(should_post_data_dump)
118   JVMTI_SUPPORT_FLAG(should_post_garbage_collection_start)
119   JVMTI_SUPPORT_FLAG(should_post_garbage_collection_finish)
120   JVMTI_SUPPORT_FLAG(should_post_on_exceptions)
121 
122   // ------ the below maybe don't have to be (but are for now)
123   // fixed conditions here ------------
124   // any events can be enabled
125   JVMTI_SUPPORT_FLAG(should_post_thread_life)
126   JVMTI_SUPPORT_FLAG(should_post_object_free)
127   JVMTI_SUPPORT_FLAG(should_post_resource_exhausted)
128 
129   // we are holding objects on the heap - need to talk to GC - e.g.
130   // breakpoint info
131   JVMTI_SUPPORT_FLAG(should_clean_up_heap_objects)
132   JVMTI_SUPPORT_FLAG(should_post_vm_object_alloc)
133   JVMTI_SUPPORT_FLAG(should_post_sampled_object_alloc)
134 
135   JVMTI_SUPPORT_FLAG(should_post_vthread_start)
136   JVMTI_SUPPORT_FLAG(should_post_vthread_end)
137   JVMTI_SUPPORT_FLAG(should_post_vthread_mount)
138   JVMTI_SUPPORT_FLAG(should_post_vthread_unmount)
139 
140   // If flag cannot be implemented, give an error if on=true
141   static void report_unsupported(bool on);
142 
143   // these should only be called by the friend class
144   friend class JvmtiManageCapabilities;
145   inline static void set_can_modify_any_class(bool on) {
146     JVMTI_ONLY(_can_modify_any_class = (on != 0);)
147   }
148   inline static void set_can_access_local_variables(bool on) {
149     JVMTI_ONLY(_can_access_local_variables = (on != 0);)
150   }
151   inline static void set_can_hotswap_or_post_breakpoint(bool on) {
152     JVMTI_ONLY(_can_hotswap_or_post_breakpoint = (on != 0);)
153   }
154   inline static void set_can_walk_any_space(bool on) {
155     JVMTI_ONLY(_can_walk_any_space = (on != 0);)
156   }
157 
158   enum {
159     JVMTI_VERSION_MASK   = 0x70000000,
160     JVMTI_VERSION_VALUE  = 0x30000000,
161     JVMDI_VERSION_VALUE  = 0x20000000
162   };
163 
164   static void post_field_modification(JavaThread *thread, Method* method, address location,
165                                       Klass* field_klass, Handle object, jfieldID field,
166                                       char sig_type, jvalue *value);
167 
168 
169   // posts a DynamicCodeGenerated event (internal/private implementation).
170   // The public post_dynamic_code_generated* functions make use of the
171   // internal implementation.  Also called from JvmtiDeferredEvent::post()
172   static void post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
173 
174   static void post_class_unload_internal(const char *name) NOT_JVMTI_RETURN;
175 
176   static void initialize_oop_storage() NOT_JVMTI_RETURN;
177   static OopStorage* jvmti_oop_storage();
178   static OopStorage* weak_tag_storage();
179  private:
180 
181   // GenerateEvents support to allow posting of CompiledMethodLoad and
182   // DynamicCodeGenerated events for a given environment.
183   friend class JvmtiCodeBlobEvents;
184 
185   static void post_dynamic_code_generated(JvmtiEnv* env, const char *name, const void *code_begin,
186                                           const void *code_end) NOT_JVMTI_RETURN;
187 
188   // This flag indicates whether RedefineClasses() has ever redefined
189   // one or more classes during the lifetime of the VM. The flag should
190   // only be set by the friend class and can be queried by other sub
191   // systems as needed to relax invariant checks.
192   static uint64_t _redefinition_count;
193   friend class VM_RedefineClasses;
194   inline static void increment_redefinition_count() {
195     JVMTI_ONLY(_redefinition_count++;)
196   }
197   // Flag to indicate if the compiler has recorded all dependencies. When the
198   // can_redefine_classes capability is enabled in the OnLoad phase then the compiler
199   // records all dependencies from startup. However if the capability is first
200   // enabled some time later then the dependencies recorded by the compiler
201   // are incomplete. This flag is used by RedefineClasses to know if the
202   // dependency information is complete or not.
203   static bool _all_dependencies_are_recorded;
204 
205   static void post_method_exit_inner(JavaThread* thread,
206                                      methodHandle& mh,
207                                      JvmtiThreadState *state,
208                                      bool exception_exit,
209                                      frame current_frame,
210                                      jvalue& value);
211 
212  public:
213   inline static bool has_redefined_a_class() {
214     JVMTI_ONLY(return _redefinition_count != 0);
215     NOT_JVMTI(return false);
216   }
217 
218   // Only set in safepoint, so no memory ordering needed.
219   inline static uint64_t redefinition_count() {
220     JVMTI_ONLY(return _redefinition_count);
221     NOT_JVMTI(return 0);
222   }
223 
224   inline static bool all_dependencies_are_recorded() {
225     return _all_dependencies_are_recorded;
226   }
227 
228   inline static void set_all_dependencies_are_recorded(bool on) {
229     _all_dependencies_are_recorded = (on != 0);
230   }
231 
232   // Add read edges to the unnamed modules of the bootstrap and app class loaders
233   static void add_default_read_edges(Handle h_module, TRAPS) NOT_JVMTI_RETURN;
234 
235   // Add a read edge to the module
236   static jvmtiError add_module_reads(Handle module, Handle to_module, TRAPS);
237 
238   // Updates a module to export a package
239   static jvmtiError add_module_exports(Handle module, Handle pkg_name, Handle to_module, TRAPS);
240 
241   // Updates a module to open a package
242   static jvmtiError add_module_opens(Handle module, Handle pkg_name, Handle to_module, TRAPS);
243 
244   // Add a used service to the module
245   static jvmtiError add_module_uses(Handle module, Handle service, TRAPS);
246 
247   // Add a service provider to the module
248   static jvmtiError add_module_provides(Handle module, Handle service, Handle impl_class, TRAPS);
249 
250   // let JVMTI know that the JVM_OnLoad code is running
251   static void enter_onload_phase() NOT_JVMTI_RETURN;
252 
253   // let JVMTI know that the VM isn't up yet (and JVM_OnLoad code isn't running)
254   static void enter_primordial_phase() NOT_JVMTI_RETURN;
255 
256   // let JVMTI know that the VM isn't up yet but JNI is live
257   static void enter_early_start_phase() NOT_JVMTI_RETURN;
258   static void enter_start_phase() NOT_JVMTI_RETURN;
259 
260   // let JVMTI know that the VM is fully up and running now
261   static void enter_live_phase() NOT_JVMTI_RETURN;
262 
263   // ------ can_* conditions (below) are set at OnLoad and never changed ------------
264   inline static bool can_modify_any_class()                       {
265     JVMTI_ONLY(return _can_modify_any_class);
266     NOT_JVMTI(return false);
267   }
268   inline static bool can_access_local_variables()                 {
269     JVMTI_ONLY(return _can_access_local_variables);
270     NOT_JVMTI(return false);
271   }
272   inline static bool can_hotswap_or_post_breakpoint()             {
273     JVMTI_ONLY(return _can_hotswap_or_post_breakpoint);
274     NOT_JVMTI(return false);
275   }
276   inline static bool can_walk_any_space()                         {
277     JVMTI_ONLY(return _can_walk_any_space);
278     NOT_JVMTI(return false);
279   }
280 
281   // field access management
282   static address  get_field_access_count_addr() NOT_JVMTI_RETURN_(0);
283 
284   // field modification management
285   static address  get_field_modification_count_addr() NOT_JVMTI_RETURN_(0);
286 
287   // -----------------
288 
289   static bool is_jvmti_version(jint version)                      {
290     JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMTI_VERSION_VALUE);
291     NOT_JVMTI(return false);
292   }
293   static bool is_jvmdi_version(jint version)                      {
294     JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMDI_VERSION_VALUE);
295     NOT_JVMTI(return false);
296   }
297   static jint get_jvmti_interface(JavaVM *jvm, void **penv, jint version) NOT_JVMTI_RETURN_(0);
298   static void decode_version_values(jint version, int * major, int * minor,
299                                     int * micro) NOT_JVMTI_RETURN;
300 
301   static void check_suspend_at_safepoint(JavaThread *thread) NOT_JVMTI_RETURN;
302 
303   // single stepping management methods
304   static void at_single_stepping_point(JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
305   static void expose_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN;
306   static bool hide_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN_(false);
307 
308   // Methods that notify the debugger that something interesting has happened in the VM.
309   static void post_early_vm_start        () NOT_JVMTI_RETURN;
310   static void post_vm_start              () NOT_JVMTI_RETURN;
311   static void post_vm_initialized        () NOT_JVMTI_RETURN;
312   static void post_vm_death              () NOT_JVMTI_RETURN;
313 
314   static void post_single_step           (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
315   static void post_raw_breakpoint        (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
316 
317   static void post_exception_throw       (JavaThread *thread, Method* method, address location, oop exception) NOT_JVMTI_RETURN;
318   static void notice_unwind_due_to_exception (JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) NOT_JVMTI_RETURN;
319 
320   static oop jni_GetField_probe          (JavaThread *thread, jobject jobj,
321     oop obj, Klass* klass, jfieldID fieldID, bool is_static)
322     NOT_JVMTI_RETURN_(NULL);
323   static void post_field_access_by_jni   (JavaThread *thread, oop obj,
324     Klass* klass, jfieldID fieldID, bool is_static) NOT_JVMTI_RETURN;
325   static void post_field_access          (JavaThread *thread, Method* method,
326     address location, Klass* field_klass, Handle object, jfieldID field) NOT_JVMTI_RETURN;
327   static oop jni_SetField_probe          (JavaThread *thread, jobject jobj,
328     oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
329     jvalue *value) NOT_JVMTI_RETURN_(NULL);
330   static void post_field_modification_by_jni(JavaThread *thread, oop obj,
331     Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
332     jvalue *value);
333   static void post_raw_field_modification(JavaThread *thread, Method* method,
334     address location, Klass* field_klass, Handle object, jfieldID field,
335     char sig_type, jvalue *value) NOT_JVMTI_RETURN;
336 
337   static void post_method_entry          (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
338   static void post_method_exit           (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
339 
340   static void post_class_load            (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
341   static void post_class_unload          (Klass* klass) NOT_JVMTI_RETURN;
342   static void post_class_prepare         (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
343 
344   static void post_thread_start          (JavaThread *thread) NOT_JVMTI_RETURN;
345   static void post_thread_end            (JavaThread *thread) NOT_JVMTI_RETURN;
346 
347   static void post_vthread_start         (jthread vthread) NOT_JVMTI_RETURN;
348   static void post_vthread_end           (jthread vthread) NOT_JVMTI_RETURN;
349   static void post_vthread_mount         (jthread vthread) NOT_JVMTI_RETURN;
350   static void post_vthread_unmount       (jthread vthread) NOT_JVMTI_RETURN;
351 
352   static void continuation_yield_cleanup (JavaThread* thread, jint continuation_frame_count) NOT_JVMTI_RETURN;
353 
354   // Support for java.lang.instrument agent loading.
355   static bool _should_post_class_file_load_hook;
356   inline static void set_should_post_class_file_load_hook(bool on)     { _should_post_class_file_load_hook = on;  }
357   inline static bool should_post_class_file_load_hook()           {
358     JVMTI_ONLY(return _should_post_class_file_load_hook);
359     NOT_JVMTI(return false;)
360   }
361   static bool is_early_phase() NOT_JVMTI_RETURN_(false);
362   static bool has_early_class_hook_env() NOT_JVMTI_RETURN_(false);
363   // Return true if the class was modified by the hook.
364   static bool post_class_file_load_hook(Symbol* h_name, Handle class_loader,
365                                         Handle h_protection_domain,
366                                         unsigned char **data_ptr, unsigned char **end_ptr,
367                                         JvmtiCachedClassFileData **cache_ptr) NOT_JVMTI_RETURN_(false);
368   static void post_native_method_bind(Method* method, address* function_ptr) NOT_JVMTI_RETURN;
369   static void post_compiled_method_load(JvmtiEnv* env, nmethod *nm) NOT_JVMTI_RETURN;
370   static void post_compiled_method_load(nmethod *nm) NOT_JVMTI_RETURN;
371   static void post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
372 
373   // used to post a CompiledMethodUnload event
374   static void post_compiled_method_unload(jmethodID mid, const void *code_begin) NOT_JVMTI_RETURN;
375 
376   // similiar to post_dynamic_code_generated except that it can be used to
377   // post a DynamicCodeGenerated event while holding locks in the VM. Any event
378   // posted using this function is recorded by the enclosing event collector
379   // -- JvmtiDynamicCodeEventCollector.
380   static void post_dynamic_code_generated_while_holding_locks(const char* name, address code_begin, address code_end) NOT_JVMTI_RETURN;
381 
382   static void post_garbage_collection_finish() NOT_JVMTI_RETURN;
383   static void post_garbage_collection_start() NOT_JVMTI_RETURN;
384   static void post_data_dump() NOT_JVMTI_RETURN;
385   static void post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
386   static void post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
387   static void post_monitor_wait(JavaThread *thread, oop obj, jlong timeout) NOT_JVMTI_RETURN;
388   static void post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) NOT_JVMTI_RETURN;
389   static void post_object_free(JvmtiEnv* env, jlong tag) NOT_JVMTI_RETURN;
390   static void post_resource_exhausted(jint resource_exhausted_flags, const char* detail) NOT_JVMTI_RETURN;
391   static void record_vm_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
392   // Post objects collected by vm_object_alloc_event_collector.
393   static void post_vm_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
394   // Collects vm internal objects for later event posting.
395   inline static void vm_object_alloc_event_collector(oop object) {
396     if (should_post_vm_object_alloc()) {
397       record_vm_internal_object_allocation(object);
398     }
399   }
400 
401   static void record_sampled_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
402   // Post objects collected by sampled_object_alloc_event_collector.
403   static void post_sampled_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
404 
405   // Collects vm internal objects for later event posting.
406   inline static void sampled_object_alloc_event_collector(oop object) {
407     if (should_post_sampled_object_alloc()) {
408       record_sampled_internal_object_allocation(object);
409     }
410   }
411 
412   inline static void post_array_size_exhausted() {
413     if (should_post_resource_exhausted()) {
414       post_resource_exhausted(JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
415                               "Requested array size exceeds VM limit");
416     }
417   }
418 
419   static void cleanup_thread             (JavaThread* thread) NOT_JVMTI_RETURN;
420   static void clear_detected_exception   (JavaThread* thread) NOT_JVMTI_RETURN;
421 
422   static void transition_pending_onload_raw_monitors() NOT_JVMTI_RETURN;
423 
424 #if INCLUDE_SERVICES
425   // attach support
426   static jint load_agent_library(const char *agent, const char *absParam, const char *options, outputStream* out) NOT_JVMTI_RETURN_(JNI_ERR);
427 #endif
428 
429   // SetNativeMethodPrefix support
430   static char** get_all_native_method_prefixes(int* count_ptr) NOT_JVMTI_RETURN_(NULL);
431 
432   // JavaThread lifecycle support:
433   static jvmtiError cv_external_thread_to_JavaThread(ThreadsList * t_list,
434                                                      jthread thread,
435                                                      JavaThread ** jt_pp,
436                                                      oop * thread_oop_p);
437   static jvmtiError cv_oop_to_JavaThread(ThreadsList * t_list, oop thread_oop,
438                                          JavaThread ** jt_pp);
439 };
440 
441 // Support class used by JvmtiDynamicCodeEventCollector and others. It
442 // describes a single code blob by name and address range.
443 class JvmtiCodeBlobDesc : public CHeapObj<mtInternal> {
444  private:
445   char _name[64];
446   address _code_begin;
447   address _code_end;
448 
449  public:
450   JvmtiCodeBlobDesc(const char *name, address code_begin, address code_end) {
451     assert(name != NULL, "all code blobs must be named");
452     strncpy(_name, name, sizeof(_name) - 1);
453     _name[sizeof(_name)-1] = '\0';
454     _code_begin = code_begin;
455     _code_end = code_end;
456   }
457   char* name()                  { return _name; }
458   address code_begin()          { return _code_begin; }
459   address code_end()            { return _code_end; }
460 };
461 
462 // JvmtiEventCollector is a helper class to setup thread for
463 // event collection.
464 class JvmtiEventCollector : public StackObj {
465  private:
466   JvmtiEventCollector* _prev;  // Save previous one to support nested event collector.
467   bool _unset_jvmti_thread_state;
468 
469  public:
470   JvmtiEventCollector() : _prev(NULL), _unset_jvmti_thread_state(false) {}
471 
472   void setup_jvmti_thread_state(); // Set this collector in current thread, returns if success.
473   void unset_jvmti_thread_state(); // Reset previous collector in current thread.
474   virtual bool is_dynamic_code_event()   { return false; }
475   virtual bool is_vm_object_alloc_event(){ return false; }
476   virtual bool is_sampled_object_alloc_event(){ return false; }
477   JvmtiEventCollector *get_prev()        { return _prev; }
478 };
479 
480 // A JvmtiDynamicCodeEventCollector is a helper class for the JvmtiExport
481 // interface. It collects "dynamic code generated" events that are posted
482 // while holding locks. When the event collector goes out of scope the
483 // events will be posted.
484 //
485 // Usage :-
486 //
487 // {
488 //   JvmtiDynamicCodeEventCollector event_collector;
489 //   :
490 //   { MutexLocker ml(...)
491 //     :
492 //     JvmtiExport::post_dynamic_code_generated_while_holding_locks(...)
493 //   }
494 //   // event collector goes out of scope => post events to profiler.
495 // }
496 
497 class JvmtiDynamicCodeEventCollector : public JvmtiEventCollector {
498  private:
499   GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs;           // collected code blob events
500 
501   friend class JvmtiExport;
502   void register_stub(const char* name, address start, address end);
503 
504  public:
505   JvmtiDynamicCodeEventCollector()  NOT_JVMTI_RETURN;
506   ~JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN;
507   bool is_dynamic_code_event()   { return true; }
508 
509 };
510 
511 // Used as a base class for object allocation collection and then posting
512 // the allocations to any event notification callbacks.
513 //
514 class JvmtiObjectAllocEventCollector : public JvmtiEventCollector {
515  protected:
516   GrowableArray<OopHandle>* _allocated;      // field to record collected allocated object oop.
517   bool _enable;                   // This flag is enabled in constructor if set up in the thread state
518                                   // and disabled in destructor before posting event. To avoid
519                                   // collection of objects allocated while running java code inside
520                                   // agent post_X_object_alloc() event handler.
521   void (*_post_callback)(JavaThread*, oop); // what callback to use when destroying the collector.
522 
523   friend class JvmtiExport;
524 
525   // Record allocated object oop.
526   inline void record_allocation(oop obj);
527 
528  public:
529   JvmtiObjectAllocEventCollector()  NOT_JVMTI_RETURN;
530 
531   void generate_call_for_allocated();
532 
533   bool is_enabled()                 { return _enable; }
534   void set_enabled(bool on)         { _enable = on; }
535 };
536 
537 // Used to record vm internally allocated object oops and post
538 // vm object alloc event for objects visible to java world.
539 // Constructor enables JvmtiThreadState flag and all vm allocated
540 // objects are recorded in a growable array. When destructor is
541 // called the vm object alloc event is posted for each object
542 // visible to java world.
543 // See jvm.cpp file for its usage.
544 //
545 class JvmtiVMObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
546  public:
547   JvmtiVMObjectAllocEventCollector()  NOT_JVMTI_RETURN;
548   ~JvmtiVMObjectAllocEventCollector()  NOT_JVMTI_RETURN;
549   virtual bool is_vm_object_alloc_event()   { return true; }
550 };
551 
552 // Used to record sampled allocated object oops and post
553 // sampled object alloc event.
554 // Constructor enables JvmtiThreadState flag and all sampled allocated
555 // objects are recorded in a growable array. When destructor is
556 // called the sampled object alloc event is posted for each sampled object.
557 // See jvm.cpp file for its usage.
558 //
559 class JvmtiSampledObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
560  public:
561   JvmtiSampledObjectAllocEventCollector()  NOT_JVMTI_RETURN;
562   ~JvmtiSampledObjectAllocEventCollector()  NOT_JVMTI_RETURN;
563   bool is_sampled_object_alloc_event()    { return true; }
564   static bool object_alloc_is_safe_to_sample() NOT_JVMTI_RETURN_(false);
565 };
566 
567 // Marker class to disable the posting of VMObjectAlloc events
568 // within its scope.
569 //
570 // Usage :-
571 //
572 // {
573 //   NoJvmtiVMObjectAllocMark njm;
574 //   :
575 //   // VMObjAlloc event will not be posted
576 //   JvmtiExport::vm_object_alloc_event_collector(obj);
577 //   :
578 // }
579 
580 class NoJvmtiVMObjectAllocMark : public StackObj {
581  private:
582   // enclosing collector if enabled, NULL otherwise
583   JvmtiVMObjectAllocEventCollector *_collector;
584 
585   bool was_enabled()    { return _collector != NULL; }
586 
587  public:
588   NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
589   ~NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
590 };
591 
592 
593 // Base class for reporting GC events to JVMTI.
594 class JvmtiGCMarker : public StackObj {
595  public:
596   JvmtiGCMarker() NOT_JVMTI_RETURN;
597   ~JvmtiGCMarker() NOT_JVMTI_RETURN;
598 };
599 
600 // JvmtiHideSingleStepping is a helper class for hiding
601 // internal single step events.
602 class JvmtiHideSingleStepping : public StackObj {
603  private:
604   bool         _single_step_hidden;
605   JavaThread * _thread;
606 
607  public:
608   JvmtiHideSingleStepping(JavaThread * thread) {
609     assert(thread != NULL, "sanity check");
610 
611     _single_step_hidden = false;
612     _thread = thread;
613     if (JvmtiExport::should_post_single_step()) {
614       _single_step_hidden = JvmtiExport::hide_single_stepping(_thread);
615     }
616   }
617 
618   ~JvmtiHideSingleStepping() {
619     if (_single_step_hidden) {
620       JvmtiExport::expose_single_stepping(_thread);
621     }
622   }
623 };
624 
625 #endif // SHARE_PRIMS_JVMTIEXPORT_HPP
--- EOF ---