1 /*
2 * Copyright (c) 1998, 2023, 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 class OopStorage;
51 class ThreadsList;
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 #if INCLUDE_JVMTI
153 // Check that _can_hotswap_or_post_breakpoint is not reset once it
154 // was set to true. When _can_hotswap_or_post_breakpoint is set to true
155 // _all_dependencies_are_recorded is also set to true and never
156 // reset so we have to ensure that evol dependencies are always
157 // recorded from that point on.
158 assert(!_can_hotswap_or_post_breakpoint || on, "sanity check");
159 _can_hotswap_or_post_breakpoint = (on != 0);
160 #endif
161 }
162 inline static void set_can_walk_any_space(bool on) {
163 JVMTI_ONLY(_can_walk_any_space = (on != 0);)
164 }
165
166 enum {
167 JVMTI_VERSION_MASK = 0x70000000,
168 JVMTI_VERSION_VALUE = 0x30000000,
169 JVMDI_VERSION_VALUE = 0x20000000
170 };
171
172 static void post_field_modification(JavaThread *thread, Method* method, address location,
173 Klass* field_klass, Handle object, jfieldID field,
174 char sig_type, jvalue *value);
175
176
177 // posts a DynamicCodeGenerated event (internal/private implementation).
178 // The public post_dynamic_code_generated* functions make use of the
179 // internal implementation. Also called from JvmtiDeferredEvent::post()
180 static void post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
181
182 static void post_class_unload_internal(const char *name) NOT_JVMTI_RETURN;
183
184 static void initialize_oop_storage() NOT_JVMTI_RETURN;
185 static OopStorage* jvmti_oop_storage();
186 static OopStorage* weak_tag_storage();
187 private:
188
189 // GenerateEvents support to allow posting of CompiledMethodLoad and
190 // DynamicCodeGenerated events for a given environment.
191 friend class JvmtiCodeBlobEvents;
192
193 static void post_dynamic_code_generated(JvmtiEnv* env, const char *name, const void *code_begin,
194 const void *code_end) NOT_JVMTI_RETURN;
195
196 // This flag indicates whether RedefineClasses() has ever redefined
197 // one or more classes during the lifetime of the VM. The flag should
198 // only be set by the friend class and can be queried by other sub
199 // systems as needed to relax invariant checks.
200 static uint64_t _redefinition_count;
201 friend class VM_RedefineClasses;
202 inline static void increment_redefinition_count() {
203 JVMTI_ONLY(_redefinition_count++;)
204 }
205 // Flag to indicate if the compiler has recorded all dependencies. When the
206 // can_redefine_classes capability is enabled in the OnLoad phase then the compiler
207 // records all dependencies from startup. However if the capability is first
208 // enabled some time later then the dependencies recorded by the compiler
209 // are incomplete. This flag is used by RedefineClasses to know if the
210 // dependency information is complete or not.
211 static bool _all_dependencies_are_recorded;
212
213 static void post_method_exit_inner(JavaThread* thread,
214 methodHandle& mh,
215 JvmtiThreadState *state,
216 bool exception_exit,
217 frame current_frame,
218 jvalue& value);
219
220 public:
221 inline static bool has_redefined_a_class() {
222 JVMTI_ONLY(return _redefinition_count != 0);
223 NOT_JVMTI(return false);
224 }
225
226 // Only set in safepoint, so no memory ordering needed.
227 inline static uint64_t redefinition_count() {
228 JVMTI_ONLY(return _redefinition_count);
229 NOT_JVMTI(return 0);
230 }
231
232 inline static bool all_dependencies_are_recorded() {
233 return _all_dependencies_are_recorded;
234 }
235
236 inline static void set_all_dependencies_are_recorded(bool on) {
237 _all_dependencies_are_recorded = (on != 0);
238 }
239
240 // Add read edges to the unnamed modules of the bootstrap and app class loaders
241 static void add_default_read_edges(Handle h_module, TRAPS) NOT_JVMTI_RETURN;
242
243 // Add a read edge to the module
244 static jvmtiError add_module_reads(Handle module, Handle to_module, TRAPS);
245
246 // Updates a module to export a package
247 static jvmtiError add_module_exports(Handle module, Handle pkg_name, Handle to_module, TRAPS);
248
249 // Updates a module to open a package
250 static jvmtiError add_module_opens(Handle module, Handle pkg_name, Handle to_module, TRAPS);
251
252 // Add a used service to the module
253 static jvmtiError add_module_uses(Handle module, Handle service, TRAPS);
254
255 // Add a service provider to the module
256 static jvmtiError add_module_provides(Handle module, Handle service, Handle impl_class, TRAPS);
257
258 // let JVMTI know that the JVM_OnLoad code is running
259 static void enter_onload_phase() NOT_JVMTI_RETURN;
260
261 // let JVMTI know that the VM isn't up yet (and JVM_OnLoad code isn't running)
262 static void enter_primordial_phase() NOT_JVMTI_RETURN;
263
264 // let JVMTI know that the VM isn't up yet but JNI is live
265 static void enter_early_start_phase() NOT_JVMTI_RETURN;
266 static void enter_start_phase() NOT_JVMTI_RETURN;
267
268 // let JVMTI know that the VM is fully up and running now
269 static void enter_live_phase() NOT_JVMTI_RETURN;
270
271 // ------ can_* conditions (below) are set at OnLoad and never changed ------------
272 inline static bool can_modify_any_class() {
273 JVMTI_ONLY(return _can_modify_any_class);
274 NOT_JVMTI(return false);
275 }
276 inline static bool can_access_local_variables() {
277 JVMTI_ONLY(return _can_access_local_variables);
278 NOT_JVMTI(return false);
279 }
280 inline static bool can_hotswap_or_post_breakpoint() {
281 JVMTI_ONLY(return _can_hotswap_or_post_breakpoint);
282 NOT_JVMTI(return false);
283 }
284 inline static bool can_walk_any_space() {
285 JVMTI_ONLY(return _can_walk_any_space);
286 NOT_JVMTI(return false);
287 }
288
289 // field access management
290 static address get_field_access_count_addr() NOT_JVMTI_RETURN_(0);
291
292 // field modification management
293 static address get_field_modification_count_addr() NOT_JVMTI_RETURN_(0);
294
295 // -----------------
296
297 static bool is_jvmti_version(jint version) {
298 JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMTI_VERSION_VALUE);
299 NOT_JVMTI(return false);
300 }
301 static bool is_jvmdi_version(jint version) {
302 JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMDI_VERSION_VALUE);
303 NOT_JVMTI(return false);
304 }
305 static jint get_jvmti_interface(JavaVM *jvm, void **penv, jint version) NOT_JVMTI_RETURN_(0);
306 static void decode_version_values(jint version, int * major, int * minor,
307 int * micro) NOT_JVMTI_RETURN;
308
309 // If the jvmti_thread_state is absent and any thread filtered event
310 // is enabled globally then it is created.
311 // Otherwise, the thread->jvmti_thread_state() is returned.
312 static JvmtiThreadState* get_jvmti_thread_state(JavaThread *thread);
313
314 // single stepping management methods
315 static void at_single_stepping_point(JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
316 static void expose_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN;
317 static bool hide_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN_(false);
318
319 // Methods that notify the debugger that something interesting has happened in the VM.
320 static void post_early_vm_start () NOT_JVMTI_RETURN;
321 static void post_vm_start () NOT_JVMTI_RETURN;
322 static void post_vm_initialized () NOT_JVMTI_RETURN;
323 static void post_vm_death () NOT_JVMTI_RETURN;
324
325 static void post_single_step (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
326 static void post_raw_breakpoint (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN;
327
328 static void post_exception_throw (JavaThread *thread, Method* method, address location, oop exception) NOT_JVMTI_RETURN;
329 static void notice_unwind_due_to_exception (JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) NOT_JVMTI_RETURN;
330
331 static oop jni_GetField_probe (JavaThread *thread, jobject jobj,
332 oop obj, Klass* klass, jfieldID fieldID, bool is_static)
333 NOT_JVMTI_RETURN_(nullptr);
334 static void post_field_access_by_jni (JavaThread *thread, oop obj,
335 Klass* klass, jfieldID fieldID, bool is_static) NOT_JVMTI_RETURN;
336 static void post_field_access (JavaThread *thread, Method* method,
337 address location, Klass* field_klass, Handle object, jfieldID field) NOT_JVMTI_RETURN;
338 static oop jni_SetField_probe (JavaThread *thread, jobject jobj,
339 oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
340 jvalue *value) NOT_JVMTI_RETURN_(nullptr);
341 static void post_field_modification_by_jni(JavaThread *thread, oop obj,
342 Klass* klass, jfieldID fieldID, bool is_static, char sig_type,
343 jvalue *value);
344 static void post_raw_field_modification(JavaThread *thread, Method* method,
345 address location, Klass* field_klass, Handle object, jfieldID field,
346 char sig_type, jvalue *value) NOT_JVMTI_RETURN;
347
348 static void post_method_entry (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
349 static void post_method_exit (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN;
350
351 static void post_class_load (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
352 static void post_class_unload (Klass* klass) NOT_JVMTI_RETURN;
353 static void post_class_prepare (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN;
354
355 static void post_thread_start (JavaThread *thread) NOT_JVMTI_RETURN;
356 static void post_thread_end (JavaThread *thread) NOT_JVMTI_RETURN;
357
358 static void post_vthread_start (jthread vthread) NOT_JVMTI_RETURN;
359 static void post_vthread_end (jthread vthread) NOT_JVMTI_RETURN;
360 static void post_vthread_mount (jthread vthread) NOT_JVMTI_RETURN;
361 static void post_vthread_unmount (jthread vthread) NOT_JVMTI_RETURN;
362
363 static void continuation_yield_cleanup (JavaThread* thread, jint continuation_frame_count) NOT_JVMTI_RETURN;
364
365 // Support for java.lang.instrument agent loading.
366 static bool _should_post_class_file_load_hook;
367 inline static void set_should_post_class_file_load_hook(bool on) { _should_post_class_file_load_hook = on; }
368 inline static bool should_post_class_file_load_hook() {
369 JVMTI_ONLY(return _should_post_class_file_load_hook);
370 NOT_JVMTI(return false;)
371 }
372 static bool is_early_phase() NOT_JVMTI_RETURN_(false);
373 static bool has_early_class_hook_env() NOT_JVMTI_RETURN_(false);
374 // Return true if the class was modified by the hook.
375 static bool post_class_file_load_hook(Symbol* h_name, Handle class_loader,
376 Handle h_protection_domain,
377 unsigned char **data_ptr, unsigned char **end_ptr,
378 JvmtiCachedClassFileData **cache_ptr) NOT_JVMTI_RETURN_(false);
379 static void post_native_method_bind(Method* method, address* function_ptr) NOT_JVMTI_RETURN;
380 static void post_compiled_method_load(JvmtiEnv* env, nmethod *nm) NOT_JVMTI_RETURN;
381 static void post_compiled_method_load(nmethod *nm) NOT_JVMTI_RETURN;
382 static void post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN;
383
384 // used to post a CompiledMethodUnload event
385 static void post_compiled_method_unload(jmethodID mid, const void *code_begin) NOT_JVMTI_RETURN;
386
387 // similar to post_dynamic_code_generated except that it can be used to
388 // post a DynamicCodeGenerated event while holding locks in the VM. Any event
389 // posted using this function is recorded by the enclosing event collector
390 // -- JvmtiDynamicCodeEventCollector.
391 static void post_dynamic_code_generated_while_holding_locks(const char* name, address code_begin, address code_end) NOT_JVMTI_RETURN;
392
393 static void post_garbage_collection_finish() NOT_JVMTI_RETURN;
394 static void post_garbage_collection_start() NOT_JVMTI_RETURN;
395 static void post_data_dump() NOT_JVMTI_RETURN;
396 static void post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
397 static void post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN;
398 static void post_monitor_wait(JavaThread *thread, oop obj, jlong timeout) NOT_JVMTI_RETURN;
399 static void post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) NOT_JVMTI_RETURN;
400 static void post_object_free(JvmtiEnv* env, GrowableArray<jlong>* objects) NOT_JVMTI_RETURN;
401 static void post_resource_exhausted(jint resource_exhausted_flags, const char* detail) NOT_JVMTI_RETURN;
402 static void record_vm_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
403 // Post objects collected by vm_object_alloc_event_collector.
404 static void post_vm_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
405 // Collects vm internal objects for later event posting.
406 inline static void vm_object_alloc_event_collector(oop object) {
407 if (should_post_vm_object_alloc()) {
408 record_vm_internal_object_allocation(object);
409 }
410 }
411
412 // Used by C2 to deoptimize allocation intrinsics and post vm_object_alloc
413 static int _should_notify_object_alloc;
414
415 static void record_sampled_internal_object_allocation(oop object) NOT_JVMTI_RETURN;
416 // Post objects collected by sampled_object_alloc_event_collector.
417 static void post_sampled_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN;
418
419 // Collects vm internal objects for later event posting.
420 inline static void sampled_object_alloc_event_collector(oop object) {
421 if (should_post_sampled_object_alloc()) {
422 record_sampled_internal_object_allocation(object);
423 }
424 }
425
426 inline static void post_array_size_exhausted() {
427 if (should_post_resource_exhausted()) {
428 post_resource_exhausted(JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
429 "Requested array size exceeds VM limit");
430 }
431 }
432
433 static void cleanup_thread (JavaThread* thread) NOT_JVMTI_RETURN;
434 static void clear_detected_exception (JavaThread* thread) NOT_JVMTI_RETURN;
435
436 static void transition_pending_onload_raw_monitors() NOT_JVMTI_RETURN;
437
438 #if INCLUDE_SERVICES
439 // attach support
440 static jint load_agent_library(const char *agent, const char *absParam, const char *options, outputStream* out) NOT_JVMTI_RETURN_(JNI_ERR);
441 #endif
442
443 // SetNativeMethodPrefix support
444 static char** get_all_native_method_prefixes(int* count_ptr) NOT_JVMTI_RETURN_(nullptr);
445
446 // JavaThread lifecycle support:
447 static jvmtiError cv_external_thread_to_JavaThread(ThreadsList * t_list,
448 jthread thread,
449 JavaThread ** jt_pp,
450 oop * thread_oop_p);
451 static jvmtiError cv_oop_to_JavaThread(ThreadsList * t_list, oop thread_oop,
452 JavaThread ** jt_pp);
453 };
454
455 // Support class used by JvmtiDynamicCodeEventCollector and others. It
456 // describes a single code blob by name and address range.
457 class JvmtiCodeBlobDesc : public CHeapObj<mtInternal> {
458 private:
459 char _name[64];
460 address _code_begin;
461 address _code_end;
462
463 public:
464 JvmtiCodeBlobDesc(const char *name, address code_begin, address code_end) {
465 assert(name != nullptr, "all code blobs must be named");
466 strncpy(_name, name, sizeof(_name) - 1);
467 _name[sizeof(_name)-1] = '\0';
468 _code_begin = code_begin;
469 _code_end = code_end;
470 }
471 char* name() { return _name; }
472 address code_begin() { return _code_begin; }
473 address code_end() { return _code_end; }
474 };
475
476 // JvmtiEventCollector is a helper class to setup thread for
477 // event collection.
478 class JvmtiEventCollector : public StackObj {
479 private:
480 JvmtiEventCollector* _prev; // Save previous one to support nested event collector.
481 bool _unset_jvmti_thread_state;
482
483 public:
484 JvmtiEventCollector() : _prev(nullptr), _unset_jvmti_thread_state(false) {}
485
486 void setup_jvmti_thread_state(); // Set this collector in current thread, returns if success.
487 void unset_jvmti_thread_state(); // Reset previous collector in current thread.
488 virtual bool is_dynamic_code_event() { return false; }
489 virtual bool is_vm_object_alloc_event(){ return false; }
490 virtual bool is_sampled_object_alloc_event(){ return false; }
491 JvmtiEventCollector *get_prev() { return _prev; }
492 };
493
494 // A JvmtiDynamicCodeEventCollector is a helper class for the JvmtiExport
495 // interface. It collects "dynamic code generated" events that are posted
496 // while holding locks. When the event collector goes out of scope the
497 // events will be posted.
498 //
499 // Usage :-
500 //
501 // {
502 // JvmtiDynamicCodeEventCollector event_collector;
503 // :
504 // { MutexLocker ml(...)
505 // :
506 // JvmtiExport::post_dynamic_code_generated_while_holding_locks(...)
507 // }
508 // // event collector goes out of scope => post events to profiler.
509 // }
510
511 class JvmtiDynamicCodeEventCollector : public JvmtiEventCollector {
512 private:
513 GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs; // collected code blob events
514
515 friend class JvmtiExport;
516 void register_stub(const char* name, address start, address end);
517
518 public:
519 JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN;
520 ~JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN;
521 bool is_dynamic_code_event() { return true; }
522
523 };
524
525 // Used as a base class for object allocation collection and then posting
526 // the allocations to any event notification callbacks.
527 //
528 class JvmtiObjectAllocEventCollector : public JvmtiEventCollector {
529 protected:
530 GrowableArray<OopHandle>* _allocated; // field to record collected allocated object oop.
531 bool _enable; // This flag is enabled in constructor if set up in the thread state
532 // and disabled in destructor before posting event. To avoid
533 // collection of objects allocated while running java code inside
534 // agent post_X_object_alloc() event handler.
535 void (*_post_callback)(JavaThread*, oop); // what callback to use when destroying the collector.
536
537 friend class JvmtiExport;
538
539 // Record allocated object oop.
540 inline void record_allocation(oop obj);
541
542 public:
543 JvmtiObjectAllocEventCollector() NOT_JVMTI_RETURN;
544
545 void generate_call_for_allocated();
546
547 bool is_enabled() { return _enable; }
548 void set_enabled(bool on) { _enable = on; }
549 };
550
551 // Used to record vm internally allocated object oops and post
552 // vm object alloc event for objects visible to java world.
553 // Constructor enables JvmtiThreadState flag and all vm allocated
554 // objects are recorded in a growable array. When destructor is
555 // called the vm object alloc event is posted for each object
556 // visible to java world.
557 // See jvm.cpp file for its usage.
558 //
559 class JvmtiVMObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
560 public:
561 JvmtiVMObjectAllocEventCollector() NOT_JVMTI_RETURN;
562 ~JvmtiVMObjectAllocEventCollector() NOT_JVMTI_RETURN;
563 virtual bool is_vm_object_alloc_event() { return true; }
564 };
565
566 // Used to record sampled allocated object oops and post
567 // sampled object alloc event.
568 // Constructor enables JvmtiThreadState flag and all sampled allocated
569 // objects are recorded in a growable array. When destructor is
570 // called the sampled object alloc event is posted for each sampled object.
571 // See jvm.cpp file for its usage.
572 //
573 class JvmtiSampledObjectAllocEventCollector : public JvmtiObjectAllocEventCollector {
574 public:
575 JvmtiSampledObjectAllocEventCollector(bool should_start = true) {
576 JVMTI_ONLY(if (should_start) start();)
577 }
578 ~JvmtiSampledObjectAllocEventCollector() NOT_JVMTI_RETURN;
579 bool is_sampled_object_alloc_event() { return true; }
580 void start() NOT_JVMTI_RETURN;
581 static bool object_alloc_is_safe_to_sample() NOT_JVMTI_RETURN_(false);
582 };
583
584 // Marker class to disable the posting of VMObjectAlloc events
585 // within its scope.
586 //
587 // Usage :-
588 //
589 // {
590 // NoJvmtiVMObjectAllocMark njm;
591 // :
592 // // VMObjAlloc event will not be posted
593 // JvmtiExport::vm_object_alloc_event_collector(obj);
594 // :
595 // }
596
597 class NoJvmtiVMObjectAllocMark : public StackObj {
598 private:
599 // enclosing collector if enabled, null otherwise
600 JvmtiVMObjectAllocEventCollector *_collector;
601
602 bool was_enabled() { return _collector != nullptr; }
603
604 public:
605 NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
606 ~NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN;
607 };
608
609
610 // Base class for reporting GC events to JVMTI.
611 class JvmtiGCMarker : public StackObj {
612 public:
613 JvmtiGCMarker() NOT_JVMTI_RETURN;
614 ~JvmtiGCMarker() NOT_JVMTI_RETURN;
615 };
616
617 // JvmtiHideSingleStepping is a helper class for hiding
618 // internal single step events.
619 class JvmtiHideSingleStepping : public StackObj {
620 private:
621 bool _single_step_hidden;
622 JavaThread * _thread;
623
624 public:
625 JvmtiHideSingleStepping(JavaThread * thread) {
626 assert(thread != nullptr, "sanity check");
627
628 _single_step_hidden = false;
629 _thread = thread;
630 if (JvmtiExport::should_post_single_step()) {
631 _single_step_hidden = JvmtiExport::hide_single_stepping(_thread);
632 }
633 }
634
635 ~JvmtiHideSingleStepping() {
636 if (_single_step_hidden) {
637 JvmtiExport::expose_single_stepping(_thread);
638 }
639 }
640 };
641
642 #endif // SHARE_PRIMS_JVMTIEXPORT_HPP