1 /*
2 * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2023, Alibaba Group Holding Limited. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "classfile/classLoaderData.inline.hpp"
28 #include "classfile/classLoaderDataGraph.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "gc/shared/workerThread.hpp"
36 #include "jfr/jfrEvents.hpp"
37 #include "jvm.h"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "memory/universe.hpp"
41 #include "oops/fieldStreams.inline.hpp"
42 #include "oops/klass.inline.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "oops/objArrayOop.inline.hpp"
45 #include "oops/flatArrayKlass.hpp"
46 #include "oops/flatArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/typeArrayOop.inline.hpp"
49 #include "runtime/continuationWrapper.inline.hpp"
50 #include "runtime/fieldDescriptor.inline.hpp"
51 #include "runtime/frame.inline.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/javaThread.inline.hpp"
55 #include "runtime/jniHandles.hpp"
56 #include "runtime/os.hpp"
57 #include "runtime/threads.hpp"
58 #include "runtime/threadSMR.hpp"
59 #include "runtime/vframe.hpp"
60 #include "runtime/vmOperations.hpp"
61 #include "runtime/vmThread.hpp"
62 #include "runtime/timerTrace.hpp"
63 #include "services/heapDumper.hpp"
64 #include "services/heapDumperCompression.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/checkedCast.hpp"
67 #include "utilities/macros.hpp"
68 #include "utilities/ostream.hpp"
69 #ifdef LINUX
70 #include "os_linux.hpp"
71 #endif
72
73 /*
74 * HPROF binary format - description copied from:
75 * src/share/demo/jvmti/hprof/hprof_io.c
76 *
77 *
78 * header "JAVA PROFILE 1.0.2" (0-terminated)
79 *
80 * u4 size of identifiers. Identifiers are used to represent
81 * UTF8 strings, objects, stack traces, etc. They usually
82 * have the same size as host pointers.
83 * u4 high word
84 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
85 * [record]* a sequence of records.
86 *
87 *
88 * Record format:
89 *
90 * u1 a TAG denoting the type of the record
91 * u4 number of *microseconds* since the time stamp in the
92 * header. (wraps around in a little more than an hour)
93 * u4 number of bytes *remaining* in the record. Note that
94 * this number excludes the tag and the length field itself.
95 * [u1]* BODY of the record (a sequence of bytes)
96 *
97 *
98 * The following TAGs are supported:
99 *
100 * TAG BODY notes
101 *----------------------------------------------------------
102 * HPROF_UTF8 a UTF8-encoded name
103 *
104 * id name ID
105 * [u1]* UTF8 characters (no trailing zero)
106 *
107 * HPROF_LOAD_CLASS a newly loaded class
108 *
109 * u4 class serial number (> 0)
110 * id class object ID
111 * u4 stack trace serial number
112 * id class name ID
113 *
114 * HPROF_UNLOAD_CLASS an unloading class
115 *
116 * u4 class serial_number
117 *
118 * HPROF_FRAME a Java stack frame
119 *
120 * id stack frame ID
121 * id method name ID
122 * id method signature ID
123 * id source file name ID
124 * u4 class serial number
125 * i4 line number. >0: normal
126 * -1: unknown
127 * -2: compiled method
128 * -3: native method
129 *
130 * HPROF_TRACE a Java stack trace
131 *
132 * u4 stack trace serial number
133 * u4 thread serial number
134 * u4 number of frames
135 * [id]* stack frame IDs
136 *
137 *
138 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
139 *
140 * u2 flags 0x0001: incremental vs. complete
141 * 0x0002: sorted by allocation vs. live
142 * 0x0004: whether to force a GC
143 * u4 cutoff ratio
144 * u4 total live bytes
145 * u4 total live instances
146 * u8 total bytes allocated
147 * u8 total instances allocated
148 * u4 number of sites that follow
149 * [u1 is_array: 0: normal object
150 * 2: object array
151 * 4: boolean array
152 * 5: char array
153 * 6: float array
154 * 7: double array
155 * 8: byte array
156 * 9: short array
157 * 10: int array
158 * 11: long array
159 * u4 class serial number (may be zero during startup)
160 * u4 stack trace serial number
161 * u4 number of bytes alive
162 * u4 number of instances alive
163 * u4 number of bytes allocated
164 * u4]* number of instance allocated
165 *
166 * HPROF_START_THREAD a newly started thread.
167 *
168 * u4 thread serial number (> 0)
169 * id thread object ID
170 * u4 stack trace serial number
171 * id thread name ID
172 * id thread group name ID
173 * id thread group parent name ID
174 *
175 * HPROF_END_THREAD a terminating thread.
176 *
177 * u4 thread serial number
178 *
179 * HPROF_HEAP_SUMMARY heap summary
180 *
181 * u4 total live bytes
182 * u4 total live instances
183 * u8 total bytes allocated
184 * u8 total instances allocated
185 *
186 * HPROF_HEAP_DUMP denote a heap dump
187 *
188 * [heap dump sub-records]*
189 *
190 * There are four kinds of heap dump sub-records:
191 *
192 * u1 sub-record type
193 *
194 * HPROF_GC_ROOT_UNKNOWN unknown root
195 *
196 * id object ID
197 *
198 * HPROF_GC_ROOT_THREAD_OBJ thread object
199 *
200 * id thread object ID (may be 0 for a
201 * thread newly attached through JNI)
202 * u4 thread sequence number
203 * u4 stack trace sequence number
204 *
205 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
206 *
207 * id object ID
208 * id JNI global ref ID
209 *
210 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
211 *
212 * id object ID
213 * u4 thread serial number
214 * u4 frame # in stack trace (-1 for empty)
215 *
216 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
217 *
218 * id object ID
219 * u4 thread serial number
220 * u4 frame # in stack trace (-1 for empty)
221 *
222 * HPROF_GC_ROOT_NATIVE_STACK Native stack
223 *
224 * id object ID
225 * u4 thread serial number
226 *
227 * HPROF_GC_ROOT_STICKY_CLASS System class
228 *
229 * id object ID
230 *
231 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
232 *
233 * id object ID
234 * u4 thread serial number
235 *
236 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
237 *
238 * id object ID
239 *
240 * HPROF_GC_CLASS_DUMP dump of a class object
241 *
242 * id class object ID
243 * u4 stack trace serial number
244 * id super class object ID
245 * id class loader object ID
246 * id signers object ID
247 * id protection domain object ID
248 * id reserved
249 * id reserved
250 *
251 * u4 instance size (in bytes)
252 *
253 * u2 size of constant pool
254 * [u2, constant pool index,
255 * ty, type
256 * 2: object
257 * 4: boolean
258 * 5: char
259 * 6: float
260 * 7: double
261 * 8: byte
262 * 9: short
263 * 10: int
264 * 11: long
265 * vl]* and value
266 *
267 * u2 number of static fields
268 * [id, static field name,
269 * ty, type,
270 * vl]* and value
271 *
272 * u2 number of inst. fields (not inc. super)
273 * [id, instance field name,
274 * ty]* type
275 *
276 * HPROF_GC_INSTANCE_DUMP dump of a normal object
277 *
278 * id object ID
279 * u4 stack trace serial number
280 * id class object ID
281 * u4 number of bytes that follow
282 * [vl]* instance field values (class, followed
283 * by super, super's super ...)
284 *
285 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
286 *
287 * id array object ID
288 * u4 stack trace serial number
289 * u4 number of elements
290 * id array class ID
291 * [id]* elements
292 *
293 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
294 *
295 * id array object ID
296 * u4 stack trace serial number
297 * u4 number of elements
298 * u1 element type
299 * 4: boolean array
300 * 5: char array
301 * 6: float array
302 * 7: double array
303 * 8: byte array
304 * 9: short array
305 * 10: int array
306 * 11: long array
307 * [u1]* elements
308 *
309 * HPROF_CPU_SAMPLES a set of sample traces of running threads
310 *
311 * u4 total number of samples
312 * u4 # of traces
313 * [u4 # of samples
314 * u4]* stack trace serial number
315 *
316 * HPROF_CONTROL_SETTINGS the settings of on/off switches
317 *
318 * u4 0x00000001: alloc traces on/off
319 * 0x00000002: cpu sampling on/off
320 * u2 stack trace depth
321 *
322 * HPROF_FLAT_ARRAYS list of flat arrays
323 *
324 * [flat array sub-records]*
325 *
326 * HPROF_FLAT_ARRAY flat array
327 *
328 * id array object ID (dumped as HPROF_GC_PRIM_ARRAY_DUMP)
329 * id element class ID (dumped by HPROF_GC_CLASS_DUMP)
330 *
331 * HPROF_INLINED_FIELDS decribes inlined fields
332 *
333 * [class with inlined fields sub-records]*
334 *
335 * HPROF_CLASS_WITH_INLINED_FIELDS
336 *
337 * id class ID (dumped as HPROF_GC_CLASS_DUMP)
338 *
339 * u2 number of instance inlined fields (not including super)
340 * [u2, inlined field index,
341 * u2, synthetic field count,
342 * id, original field name,
343 * id]* inlined field class ID (dumped by HPROF_GC_CLASS_DUMP)
344 *
345 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
346 * be generated as a sequence of heap dump segments. This sequence is
347 * terminated by an end record. The additional tags allowed by format
348 * "JAVA PROFILE 1.0.2" are:
349 *
350 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
351 *
352 * [heap dump sub-records]*
353 * The same sub-record types allowed by HPROF_HEAP_DUMP
354 *
355 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
356 *
357 */
358
359
360 // HPROF tags
361
362 enum hprofTag : u1 {
363 // top-level records
364 HPROF_UTF8 = 0x01,
365 HPROF_LOAD_CLASS = 0x02,
366 HPROF_UNLOAD_CLASS = 0x03,
367 HPROF_FRAME = 0x04,
368 HPROF_TRACE = 0x05,
369 HPROF_ALLOC_SITES = 0x06,
370 HPROF_HEAP_SUMMARY = 0x07,
371 HPROF_START_THREAD = 0x0A,
372 HPROF_END_THREAD = 0x0B,
373 HPROF_HEAP_DUMP = 0x0C,
374 HPROF_CPU_SAMPLES = 0x0D,
375 HPROF_CONTROL_SETTINGS = 0x0E,
376
377 // 1.0.2 record types
378 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
379 HPROF_HEAP_DUMP_END = 0x2C,
380
381 // inlined object support
382 HPROF_FLAT_ARRAYS = 0x12,
383 HPROF_INLINED_FIELDS = 0x13,
384 // inlined object subrecords
385 HPROF_FLAT_ARRAY = 0x01,
386 HPROF_CLASS_WITH_INLINED_FIELDS = 0x01,
387
388 // field types
389 HPROF_ARRAY_OBJECT = 0x01,
390 HPROF_NORMAL_OBJECT = 0x02,
391 HPROF_BOOLEAN = 0x04,
392 HPROF_CHAR = 0x05,
393 HPROF_FLOAT = 0x06,
394 HPROF_DOUBLE = 0x07,
395 HPROF_BYTE = 0x08,
396 HPROF_SHORT = 0x09,
397 HPROF_INT = 0x0A,
398 HPROF_LONG = 0x0B,
399
400 // data-dump sub-records
401 HPROF_GC_ROOT_UNKNOWN = 0xFF,
402 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
403 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
404 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
405 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
406 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
407 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
408 HPROF_GC_ROOT_MONITOR_USED = 0x07,
409 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
410 HPROF_GC_CLASS_DUMP = 0x20,
411 HPROF_GC_INSTANCE_DUMP = 0x21,
412 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
413 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
414 };
415
416 // Default stack trace ID (used for dummy HPROF_TRACE record)
417 enum {
418 STACK_TRACE_ID = 1,
419 INITIAL_CLASS_COUNT = 200
420 };
421
422
423 class AbstractDumpWriter;
424
425 class InlinedObjects {
426
427 struct ClassInlinedFields {
428 const Klass *klass;
429 uintx base_index; // base index of the inlined field names (1st field has index base_index+1).
430 ClassInlinedFields(const Klass *klass = nullptr, uintx base_index = 0) : klass(klass), base_index(base_index) {}
431
432 // For GrowableArray::find_sorted().
433 static int compare(const ClassInlinedFields& a, const ClassInlinedFields& b) {
434 return a.klass - b.klass;
435 }
436 // For GrowableArray::sort().
437 static int compare(ClassInlinedFields* a, ClassInlinedFields* b) {
438 return compare(*a, *b);
439 }
440 };
441
442 uintx _min_string_id;
443 uintx _max_string_id;
444
445 GrowableArray<ClassInlinedFields> *_inlined_field_map;
446
447 // counters for classes with inlined fields and for the fields
448 int _classes_count;
449 int _inlined_fields_count;
450
451 static InlinedObjects *_instance;
452
453 static void inlined_field_names_callback(InlinedObjects* _this, const Klass *klass, uintx base_index, int count);
454
455 GrowableArray<oop> *_flat_arrays;
456
457 public:
458 InlinedObjects()
459 : _min_string_id(0), _max_string_id(0),
460 _inlined_field_map(nullptr),
461 _classes_count(0), _inlined_fields_count(0),
462 _flat_arrays(nullptr) {
463 }
464
465 static InlinedObjects* get_instance() {
466 return _instance;
467 }
468
469 void init();
470 void release();
471
472 void dump_inlined_field_names(AbstractDumpWriter *writer);
473
474 uintx get_base_index_for(Klass* k);
475 uintx get_next_string_id(uintx id);
476
477 void dump_classed_with_inlined_fields(AbstractDumpWriter* writer);
478
479 void add_flat_array(oop array);
480 void dump_flat_arrays(AbstractDumpWriter* writer);
481
482 };
483
484 InlinedObjects *InlinedObjects::_instance = nullptr;
485
486
487 // Supports I/O operations for a dump
488 // Base class for dump and parallel dump
489 class AbstractDumpWriter : public CHeapObj<mtInternal> {
490 protected:
491 enum {
492 io_buffer_max_size = 1*M,
493 dump_segment_header_size = 9
494 };
495
496 char* _buffer; // internal buffer
497 size_t _size;
498 size_t _pos;
499
500 bool _in_dump_segment; // Are we currently in a dump segment?
501 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
502 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
503 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
504
505 char* buffer() const { return _buffer; }
506 size_t buffer_size() const { return _size; }
507 void set_position(size_t pos) { _pos = pos; }
508
509 // Can be called if we have enough room in the buffer.
510 void write_fast(const void* s, size_t len);
511
512 // Returns true if we have enough room in the buffer for 'len' bytes.
513 bool can_write_fast(size_t len);
514
515 void write_address(address a);
516
517 public:
518 AbstractDumpWriter() :
519 _buffer(nullptr),
520 _size(io_buffer_max_size),
521 _pos(0),
522 _in_dump_segment(false) { }
523
524 // Total number of bytes written to the disk
525 virtual julong bytes_written() const = 0;
526 // Return non-null if error occurred
527 virtual char const* error() const = 0;
528
529 size_t position() const { return _pos; }
530 // writer functions
531 virtual void write_raw(const void* s, size_t len);
532 void write_u1(u1 x);
533 void write_u2(u2 x);
534 void write_u4(u4 x);
535 void write_u8(u8 x);
536 void write_objectID(oop o);
537 void write_rootID(oop* p);
538 void write_symbolID(Symbol* o);
539 void write_classID(Klass* k);
540 void write_id(u4 x);
541
542 // Start a new sub-record. Starts a new heap dump segment if needed.
543 void start_sub_record(u1 tag, u4 len);
544 // Ends the current sub-record.
545 void end_sub_record();
546 // Finishes the current dump segment if not already finished.
547 void finish_dump_segment();
548 // Flush internal buffer to persistent storage
549 virtual void flush() = 0;
550 };
551
552 void AbstractDumpWriter::write_fast(const void* s, size_t len) {
553 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
554 assert(buffer_size() - position() >= len, "Must fit");
555 debug_only(_sub_record_left -= len);
556 memcpy(buffer() + position(), s, len);
557 set_position(position() + len);
558 }
559
560 bool AbstractDumpWriter::can_write_fast(size_t len) {
561 return buffer_size() - position() >= len;
562 }
563
564 // write raw bytes
565 void AbstractDumpWriter::write_raw(const void* s, size_t len) {
566 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
567 debug_only(_sub_record_left -= len);
568
569 // flush buffer to make room.
570 while (len > buffer_size() - position()) {
571 assert(!_in_dump_segment || _is_huge_sub_record,
572 "Cannot overflow in non-huge sub-record.");
573 size_t to_write = buffer_size() - position();
574 memcpy(buffer() + position(), s, to_write);
575 s = (void*) ((char*) s + to_write);
576 len -= to_write;
577 set_position(position() + to_write);
578 flush();
579 }
580
581 memcpy(buffer() + position(), s, len);
582 set_position(position() + len);
583 }
584
585 // Makes sure we inline the fast write into the write_u* functions. This is a big speedup.
586 #define WRITE_KNOWN_TYPE(p, len) do { if (can_write_fast((len))) write_fast((p), (len)); \
587 else write_raw((p), (len)); } while (0)
588
589 void AbstractDumpWriter::write_u1(u1 x) {
590 WRITE_KNOWN_TYPE(&x, 1);
591 }
592
593 void AbstractDumpWriter::write_u2(u2 x) {
594 u2 v;
595 Bytes::put_Java_u2((address)&v, x);
596 WRITE_KNOWN_TYPE(&v, 2);
597 }
598
599 void AbstractDumpWriter::write_u4(u4 x) {
600 u4 v;
601 Bytes::put_Java_u4((address)&v, x);
602 WRITE_KNOWN_TYPE(&v, 4);
603 }
604
605 void AbstractDumpWriter::write_u8(u8 x) {
606 u8 v;
607 Bytes::put_Java_u8((address)&v, x);
608 WRITE_KNOWN_TYPE(&v, 8);
609 }
610
611 void AbstractDumpWriter::write_address(address a) {
612 #ifdef _LP64
613 write_u8((u8)a);
614 #else
615 write_u4((u4)a);
616 #endif
617 }
618
619 void AbstractDumpWriter::write_objectID(oop o) {
620 write_address(cast_from_oop<address>(o));
621 }
622
623 void AbstractDumpWriter::write_rootID(oop* p) {
624 write_address((address)p);
625 }
626
627 void AbstractDumpWriter::write_symbolID(Symbol* s) {
628 write_address((address)((uintptr_t)s));
629 }
630
631 void AbstractDumpWriter::write_id(u4 x) {
632 #ifdef _LP64
633 write_u8((u8) x);
634 #else
635 write_u4(x);
636 #endif
637 }
638
639 // We use java mirror as the class ID
640 void AbstractDumpWriter::write_classID(Klass* k) {
641 write_objectID(k->java_mirror());
642 }
643
644 void AbstractDumpWriter::finish_dump_segment() {
645 if (_in_dump_segment) {
646 assert(_sub_record_left == 0, "Last sub-record not written completely");
647 assert(_sub_record_ended, "sub-record must have ended");
648
649 // Fix up the dump segment length if we haven't written a huge sub-record last
650 // (in which case the segment length was already set to the correct value initially).
651 if (!_is_huge_sub_record) {
652 assert(position() > dump_segment_header_size, "Dump segment should have some content");
653 Bytes::put_Java_u4((address) (buffer() + 5),
654 (u4) (position() - dump_segment_header_size));
655 } else {
656 // Finish process huge sub record
657 // Set _is_huge_sub_record to false so the parallel dump writer can flush data to file.
658 _is_huge_sub_record = false;
659 }
660
661 _in_dump_segment = false;
662 flush();
663 }
664 }
665
666 void AbstractDumpWriter::start_sub_record(u1 tag, u4 len) {
667 if (!_in_dump_segment) {
668 if (position() > 0) {
669 flush();
670 }
671
672 assert(position() == 0 && buffer_size() > dump_segment_header_size, "Must be at the start");
673
674 write_u1(HPROF_HEAP_DUMP_SEGMENT);
675 write_u4(0); // timestamp
676 // Will be fixed up later if we add more sub-records. If this is a huge sub-record,
677 // this is already the correct length, since we don't add more sub-records.
678 write_u4(len);
679 assert(Bytes::get_Java_u4((address)(buffer() + 5)) == len, "Inconsistent size!");
680 _in_dump_segment = true;
681 _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
682 } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
683 // This object will not fit in completely or the last sub-record was huge.
684 // Finish the current segment and try again.
685 finish_dump_segment();
686 start_sub_record(tag, len);
687
688 return;
689 }
690
691 debug_only(_sub_record_left = len);
692 debug_only(_sub_record_ended = false);
693
694 write_u1(tag);
695 }
696
697 void AbstractDumpWriter::end_sub_record() {
698 assert(_in_dump_segment, "must be in dump segment");
699 assert(_sub_record_left == 0, "sub-record not written completely");
700 assert(!_sub_record_ended, "Must not have ended yet");
701 debug_only(_sub_record_ended = true);
702 }
703
704 // Supports I/O operations for a dump
705
706 class DumpWriter : public AbstractDumpWriter {
707 private:
708 FileWriter* _writer;
709 AbstractCompressor* _compressor;
710 size_t _bytes_written;
711 char* _error;
712 // Compression support
713 char* _out_buffer;
714 size_t _out_size;
715 size_t _out_pos;
716 char* _tmp_buffer;
717 size_t _tmp_size;
718
719 private:
720 void do_compress();
721
722 public:
723 DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor);
724 ~DumpWriter();
725 julong bytes_written() const override { return (julong) _bytes_written; }
726 char const* error() const override { return _error; }
727 void set_error(const char* error) { _error = (char*)error; }
728 bool has_error() const { return _error != nullptr; }
729 const char* get_file_path() const { return _writer->get_file_path(); }
730 AbstractCompressor* compressor() { return _compressor; }
731 bool is_overwrite() const { return _writer->is_overwrite(); }
732
733 void flush() override;
734
735 private:
736 // internals for DumpMerger
737 friend class DumpMerger;
738 void set_bytes_written(julong bytes_written) { _bytes_written = bytes_written; }
739 int get_fd() const { return _writer->get_fd(); }
740 void set_compressor(AbstractCompressor* p) { _compressor = p; }
741 };
742
743 DumpWriter::DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor) :
744 AbstractDumpWriter(),
745 _writer(new (std::nothrow) FileWriter(path, overwrite)),
746 _compressor(compressor),
747 _bytes_written(0),
748 _error(nullptr),
749 _out_buffer(nullptr),
750 _out_size(0),
751 _out_pos(0),
752 _tmp_buffer(nullptr),
753 _tmp_size(0) {
754 _error = (char*)_writer->open_writer();
755 if (_error == nullptr) {
756 _buffer = (char*)os::malloc(io_buffer_max_size, mtInternal);
757 if (compressor != nullptr) {
758 _error = (char*)_compressor->init(io_buffer_max_size, &_out_size, &_tmp_size);
759 if (_error == nullptr) {
760 if (_out_size > 0) {
761 _out_buffer = (char*)os::malloc(_out_size, mtInternal);
762 }
763 if (_tmp_size > 0) {
764 _tmp_buffer = (char*)os::malloc(_tmp_size, mtInternal);
765 }
766 }
767 }
768 }
769 // initialize internal buffer
770 _pos = 0;
771 _size = io_buffer_max_size;
772 }
773
774 DumpWriter::~DumpWriter(){
775 if (_buffer != nullptr) {
776 os::free(_buffer);
777 }
778 if (_out_buffer != nullptr) {
779 os::free(_out_buffer);
780 }
781 if (_tmp_buffer != nullptr) {
782 os::free(_tmp_buffer);
783 }
784 if (_writer != nullptr) {
785 delete _writer;
786 }
787 _bytes_written = -1;
788 }
789
790 // flush any buffered bytes to the file
791 void DumpWriter::flush() {
792 if (_pos <= 0) {
793 return;
794 }
795 if (has_error()) {
796 _pos = 0;
797 return;
798 }
799 char* result = nullptr;
800 if (_compressor == nullptr) {
801 result = (char*)_writer->write_buf(_buffer, _pos);
802 _bytes_written += _pos;
803 } else {
804 do_compress();
805 if (!has_error()) {
806 result = (char*)_writer->write_buf(_out_buffer, _out_pos);
807 _bytes_written += _out_pos;
808 }
809 }
810 _pos = 0; // reset pos to make internal buffer available
811
812 if (result != nullptr) {
813 set_error(result);
814 }
815 }
816
817 void DumpWriter::do_compress() {
818 const char* msg = _compressor->compress(_buffer, _pos, _out_buffer, _out_size,
819 _tmp_buffer, _tmp_size, &_out_pos);
820
821 if (msg != nullptr) {
822 set_error(msg);
823 }
824 }
825
826 class DumperClassCacheTable;
827 class DumperClassCacheTableEntry;
828
829 // Support class with a collection of functions used when dumping the heap
830 class DumperSupport : AllStatic {
831 public:
832
833 // write a header of the given type
834 static void write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len);
835
836 // returns hprof tag for the given type signature
837 static hprofTag sig2tag(Symbol* sig);
838 // returns hprof tag for the given basic type
839 static hprofTag type2tag(BasicType type);
840 // Returns the size of the data to write.
841 static u4 sig2size(Symbol* sig);
842
843 // calculates the total size of the all fields of the given class.
844 static u4 instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry = nullptr);
845
846 // dump a jfloat
847 static void dump_float(AbstractDumpWriter* writer, jfloat f);
848 // dump a jdouble
849 static void dump_double(AbstractDumpWriter* writer, jdouble d);
850 // dumps the raw value of the given field
851 static void dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset);
852 // returns the size of the static fields; also counts the static fields
853 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
854 // dumps static fields of the given class
855 static void dump_static_fields(AbstractDumpWriter* writer, Klass* k);
856 // dump the raw values of the instance fields of the given identity or inlined object;
857 // for identity objects offset is 0 and 'klass' is o->klass(),
858 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class
859 static void dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
860 // dump the raw values of the instance fields of the given inlined object;
861 // dump_instance_fields wrapper for inlined objects
862 static void dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
863
864 // get the count of the instance fields for a given class
865 static u2 get_instance_fields_count(InstanceKlass* ik);
866 // dumps the definition of the instance fields for a given class
867 static void dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* k, uintx *inlined_fields_index = nullptr);
868 // creates HPROF_GC_INSTANCE_DUMP record for the given object
869 static void dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache);
870 // creates HPROF_GC_CLASS_DUMP record for the given instance class
871 static void dump_instance_class(AbstractDumpWriter* writer, Klass* k);
872 // creates HPROF_GC_CLASS_DUMP record for a given array class
873 static void dump_array_class(AbstractDumpWriter* writer, Klass* k);
874
875 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
876 static void dump_object_array(AbstractDumpWriter* writer, objArrayOop array);
877 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
878 static void dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache);
879 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
880 static void dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array);
881 // create HPROF_FRAME record for the given method and bci
882 static void dump_stack_frame(AbstractDumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
883
884 // check if we need to truncate an array
885 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size);
886 // extended version to dump flat arrays as primitive arrays;
887 // type_size specifies size of the inlined objects.
888 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size);
889
890 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
891 static void end_of_dump(AbstractDumpWriter* writer);
892
893 static oop mask_dormant_archived_object(oop o, oop ref_obj) {
894 if (o != nullptr && o->klass()->java_mirror_no_keepalive() == nullptr) {
895 // Ignore this object since the corresponding java mirror is not loaded.
896 // Might be a dormant archive object.
897 report_dormant_archived_object(o, ref_obj);
898 return nullptr;
899 } else {
900 return o;
901 }
902 }
903
904 // helper methods for inlined fields.
905 static bool is_inlined_field(const fieldDescriptor& fld) {
906 return fld.is_flat();
907 }
908 static InlineKlass* get_inlined_field_klass(const fieldDescriptor& fld) {
909 assert(is_inlined_field(fld), "must be inlined field");
910 InstanceKlass* holder_klass = fld.field_holder();
911 return InlineKlass::cast(holder_klass->get_inline_type_field_klass(fld.index()));
912 }
913
914 static void report_dormant_archived_object(oop o, oop ref_obj) {
915 if (log_is_enabled(Trace, cds, heap)) {
916 ResourceMark rm;
917 if (ref_obj != nullptr) {
918 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
919 p2i(o), o->klass()->external_name(),
920 p2i(ref_obj), ref_obj->klass()->external_name());
921 } else {
922 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)",
923 p2i(o), o->klass()->external_name());
924 }
925 }
926 }
927 };
928
929 // Hash table of klasses to the klass metadata. This should greatly improve the
930 // hash dumping performance. This hash table is supposed to be used by a single
931 // thread only.
932 //
933 class DumperClassCacheTableEntry : public CHeapObj<mtServiceability> {
934 friend class DumperClassCacheTable;
935 private:
936 GrowableArray<char> _sigs_start;
937 GrowableArray<int> _offsets;
938 GrowableArray<InlineKlass*> _inline_klasses;
939 u4 _instance_size;
940 int _entries;
941
942 public:
943 DumperClassCacheTableEntry() : _instance_size(0), _entries(0) {};
944
945 int field_count() { return _entries; }
946 char sig_start(int field_idx) { return _sigs_start.at(field_idx); }
947 void push_sig_start_inlined() { _sigs_start.push('Q'); }
948 bool is_inlined(int field_idx){ return _sigs_start.at(field_idx) == 'Q'; }
949 InlineKlass* inline_klass(int field_idx) { assert(is_inlined(field_idx), "Not inlined"); return _inline_klasses.at(field_idx); }
950 int offset(int field_idx) { return _offsets.at(field_idx); }
951 u4 instance_size() { return _instance_size; }
952 };
953
954 class DumperClassCacheTable {
955 private:
956 // ResourceHashtable SIZE is specified at compile time so we
957 // use 1031 which is the first prime after 1024.
958 static constexpr size_t TABLE_SIZE = 1031;
959
960 // Maintain the cache for N classes. This limits memory footprint
961 // impact, regardless of how many classes we have in the dump.
962 // This also improves look up performance by keeping the statically
963 // sized table from overloading.
964 static constexpr int CACHE_TOP = 256;
965
966 typedef ResourceHashtable<InstanceKlass*, DumperClassCacheTableEntry*,
967 TABLE_SIZE, AnyObj::C_HEAP, mtServiceability> PtrTable;
968 PtrTable* _ptrs;
969
970 // Single-slot cache to handle the major case of objects of the same
971 // class back-to-back, e.g. from T[].
972 InstanceKlass* _last_ik;
973 DumperClassCacheTableEntry* _last_entry;
974
975 void unlink_all(PtrTable* table) {
976 class CleanupEntry: StackObj {
977 public:
978 bool do_entry(InstanceKlass*& key, DumperClassCacheTableEntry*& entry) {
979 delete entry;
980 return true;
981 }
982 } cleanup;
983 table->unlink(&cleanup);
984 }
985
986 public:
987 DumperClassCacheTableEntry* lookup_or_create(InstanceKlass* ik) {
988 if (_last_ik == ik) {
989 return _last_entry;
990 }
991
992 DumperClassCacheTableEntry* entry;
993 DumperClassCacheTableEntry** from_cache = _ptrs->get(ik);
994 if (from_cache == nullptr) {
995 entry = new DumperClassCacheTableEntry();
996 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
997 if (!fld.access_flags().is_static()) {
998 InlineKlass* inlineKlass = nullptr;
999 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1000 inlineKlass = DumperSupport::get_inlined_field_klass(fld.field_descriptor());
1001 entry->push_sig_start_inlined();
1002 entry->_instance_size += DumperSupport::instance_size(inlineKlass);
1003 } else {
1004 Symbol* sig = fld.signature();
1005 entry->_sigs_start.push(sig->char_at(0));
1006 entry->_instance_size += DumperSupport::sig2size(sig);
1007 }
1008 entry->_inline_klasses.push(inlineKlass);
1009 entry->_offsets.push(fld.offset());
1010 entry->_entries++;
1011 }
1012 }
1013
1014 if (_ptrs->number_of_entries() >= CACHE_TOP) {
1015 // We do not track the individual hit rates for table entries.
1016 // Purge the entire table, and let the cache catch up with new
1017 // distribution.
1018 unlink_all(_ptrs);
1019 }
1020
1021 _ptrs->put(ik, entry);
1022 } else {
1023 entry = *from_cache;
1024 }
1025
1026 // Remember for single-slot cache.
1027 _last_ik = ik;
1028 _last_entry = entry;
1029
1030 return entry;
1031 }
1032
1033 DumperClassCacheTable() : _ptrs(new (mtServiceability) PtrTable), _last_ik(nullptr), _last_entry(nullptr) {}
1034
1035 ~DumperClassCacheTable() {
1036 unlink_all(_ptrs);
1037 delete _ptrs;
1038 }
1039 };
1040
1041 // write a header of the given type
1042 void DumperSupport:: write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len) {
1043 writer->write_u1(tag);
1044 writer->write_u4(0); // current ticks
1045 writer->write_u4(len);
1046 }
1047
1048 // returns hprof tag for the given type signature
1049 hprofTag DumperSupport::sig2tag(Symbol* sig) {
1050 switch (sig->char_at(0)) {
1051 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
1052 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
1053 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
1054 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
1055 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
1056 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
1057 case JVM_SIGNATURE_INT : return HPROF_INT;
1058 case JVM_SIGNATURE_LONG : return HPROF_LONG;
1059 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
1060 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
1061 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1062 }
1063 }
1064
1065 hprofTag DumperSupport::type2tag(BasicType type) {
1066 switch (type) {
1067 case T_BYTE : return HPROF_BYTE;
1068 case T_CHAR : return HPROF_CHAR;
1069 case T_FLOAT : return HPROF_FLOAT;
1070 case T_DOUBLE : return HPROF_DOUBLE;
1071 case T_INT : return HPROF_INT;
1072 case T_LONG : return HPROF_LONG;
1073 case T_SHORT : return HPROF_SHORT;
1074 case T_BOOLEAN : return HPROF_BOOLEAN;
1075 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1076 }
1077 }
1078
1079 u4 DumperSupport::sig2size(Symbol* sig) {
1080 switch (sig->char_at(0)) {
1081 case JVM_SIGNATURE_CLASS:
1082 case JVM_SIGNATURE_ARRAY: return sizeof(address);
1083 case JVM_SIGNATURE_BOOLEAN:
1084 case JVM_SIGNATURE_BYTE: return 1;
1085 case JVM_SIGNATURE_SHORT:
1086 case JVM_SIGNATURE_CHAR: return 2;
1087 case JVM_SIGNATURE_INT:
1088 case JVM_SIGNATURE_FLOAT: return 4;
1089 case JVM_SIGNATURE_LONG:
1090 case JVM_SIGNATURE_DOUBLE: return 8;
1091 default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
1092 }
1093 }
1094
1095 template<typename T, typename F> T bit_cast(F from) { // replace with the real thing when we can use c++20
1096 T to;
1097 static_assert(sizeof(to) == sizeof(from), "must be of the same size");
1098 memcpy(&to, &from, sizeof(to));
1099 return to;
1100 }
1101
1102 // dump a jfloat
1103 void DumperSupport::dump_float(AbstractDumpWriter* writer, jfloat f) {
1104 if (g_isnan(f)) {
1105 writer->write_u4(0x7fc00000); // collapsing NaNs
1106 } else {
1107 writer->write_u4(bit_cast<u4>(f));
1108 }
1109 }
1110
1111 // dump a jdouble
1112 void DumperSupport::dump_double(AbstractDumpWriter* writer, jdouble d) {
1113 if (g_isnan(d)) {
1114 writer->write_u8(0x7ff80000ull << 32); // collapsing NaNs
1115 } else {
1116 writer->write_u8(bit_cast<u8>(d));
1117 }
1118 }
1119
1120
1121 // dumps the raw value of the given field
1122 void DumperSupport::dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset) {
1123 switch (type) {
1124 case JVM_SIGNATURE_CLASS :
1125 case JVM_SIGNATURE_ARRAY : {
1126 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
1127 o = mask_dormant_archived_object(o, obj);
1128 assert(oopDesc::is_oop_or_null(o), "Expected an oop or nullptr at " PTR_FORMAT, p2i(o));
1129 writer->write_objectID(o);
1130 break;
1131 }
1132 case JVM_SIGNATURE_BYTE : {
1133 jbyte b = obj->byte_field(offset);
1134 writer->write_u1(b);
1135 break;
1136 }
1137 case JVM_SIGNATURE_CHAR : {
1138 jchar c = obj->char_field(offset);
1139 writer->write_u2(c);
1140 break;
1141 }
1142 case JVM_SIGNATURE_SHORT : {
1143 jshort s = obj->short_field(offset);
1144 writer->write_u2(s);
1145 break;
1146 }
1147 case JVM_SIGNATURE_FLOAT : {
1148 jfloat f = obj->float_field(offset);
1149 dump_float(writer, f);
1150 break;
1151 }
1152 case JVM_SIGNATURE_DOUBLE : {
1153 jdouble d = obj->double_field(offset);
1154 dump_double(writer, d);
1155 break;
1156 }
1157 case JVM_SIGNATURE_INT : {
1158 jint i = obj->int_field(offset);
1159 writer->write_u4(i);
1160 break;
1161 }
1162 case JVM_SIGNATURE_LONG : {
1163 jlong l = obj->long_field(offset);
1164 writer->write_u8(l);
1165 break;
1166 }
1167 case JVM_SIGNATURE_BOOLEAN : {
1168 jboolean b = obj->bool_field(offset);
1169 writer->write_u1(b);
1170 break;
1171 }
1172 default : {
1173 ShouldNotReachHere();
1174 break;
1175 }
1176 }
1177 }
1178
1179 // calculates the total size of the all fields of the given class.
1180 u4 DumperSupport::instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry) {
1181 if (class_cache_entry != nullptr) {
1182 return class_cache_entry->instance_size();
1183 } else {
1184 u4 size = 0;
1185 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1186 if (!fld.access_flags().is_static()) {
1187 if (is_inlined_field(fld.field_descriptor())) {
1188 size += instance_size(get_inlined_field_klass(fld.field_descriptor()));
1189 } else {
1190 size += sig2size(fld.signature());
1191 }
1192 }
1193 }
1194 return size;
1195 }
1196 }
1197
1198 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1199 field_count = 0;
1200 u4 size = 0;
1201
1202 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1203 if (fldc.access_flags().is_static()) {
1204 assert(!is_inlined_field(fldc.field_descriptor()), "static fields cannot be inlined");
1205
1206 field_count++;
1207 size += sig2size(fldc.signature());
1208 }
1209 }
1210
1211 // Add in resolved_references which is referenced by the cpCache
1212 // The resolved_references is an array per InstanceKlass holding the
1213 // strings and other oops resolved from the constant pool.
1214 oop resolved_references = ik->constants()->resolved_references_or_null();
1215 if (resolved_references != nullptr) {
1216 field_count++;
1217 size += sizeof(address);
1218
1219 // Add in the resolved_references of the used previous versions of the class
1220 // in the case of RedefineClasses
1221 InstanceKlass* prev = ik->previous_versions();
1222 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1223 field_count++;
1224 size += sizeof(address);
1225 prev = prev->previous_versions();
1226 }
1227 }
1228
1229 // We write the value itself plus a name and a one byte type tag per field.
1230 return checked_cast<u4>(size + field_count * (sizeof(address) + 1));
1231 }
1232
1233 // dumps static fields of the given class
1234 void DumperSupport::dump_static_fields(AbstractDumpWriter* writer, Klass* k) {
1235 InstanceKlass* ik = InstanceKlass::cast(k);
1236
1237 // dump the field descriptors and raw values
1238 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1239 if (fld.access_flags().is_static()) {
1240 assert(!is_inlined_field(fld.field_descriptor()), "static fields cannot be inlined");
1241
1242 Symbol* sig = fld.signature();
1243
1244 writer->write_symbolID(fld.name()); // name
1245 writer->write_u1(sig2tag(sig)); // type
1246
1247 // value
1248 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1249 }
1250 }
1251
1252 // Add resolved_references for each class that has them
1253 oop resolved_references = ik->constants()->resolved_references_or_null();
1254 if (resolved_references != nullptr) {
1255 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1256 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1257 writer->write_objectID(resolved_references);
1258
1259 // Also write any previous versions
1260 InstanceKlass* prev = ik->previous_versions();
1261 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1262 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1263 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1264 writer->write_objectID(prev->constants()->resolved_references());
1265 prev = prev->previous_versions();
1266 }
1267 }
1268 }
1269
1270 // dump the raw values of the instance fields of the given identity or inlined object;
1271 // for identity objects offset is 0 and 'klass' is o->klass(),
1272 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class.
1273 void DumperSupport::dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1274 assert(class_cache_entry != nullptr, "Pre-condition: must be provided");
1275 for (int idx = 0; idx < class_cache_entry->field_count(); idx++) {
1276 if (class_cache_entry->is_inlined(idx)) {
1277 InlineKlass* field_klass = class_cache_entry->inline_klass(idx);
1278 int fields_offset = offset + (class_cache_entry->offset(idx) - field_klass->first_field_offset());
1279 DumperClassCacheTableEntry* inline_class_cache_entry = class_cache->lookup_or_create(field_klass);
1280 dump_inlined_object_fields(writer, o, fields_offset, class_cache, inline_class_cache_entry);
1281 } else {
1282 dump_field_value(writer, class_cache_entry->sig_start(idx), o, class_cache_entry->offset(idx));
1283 }
1284 }
1285 }
1286
1287 void DumperSupport::dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1288 // the object is inlined, so all its fields are stored without headers.
1289 dump_instance_fields(writer, o, offset, class_cache, class_cache_entry);
1290 }
1291
1292 // gets the count of the instance fields for a given class
1293 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1294 u2 field_count = 0;
1295
1296 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1297 if (!fldc.access_flags().is_static()) {
1298 if (is_inlined_field(fldc.field_descriptor())) {
1299 // add "synthetic" fields for inlined fields.
1300 field_count += get_instance_fields_count(get_inlined_field_klass(fldc.field_descriptor()));
1301 } else {
1302 field_count++;
1303 }
1304 }
1305 }
1306
1307 return field_count;
1308 }
1309
1310 // dumps the definition of the instance fields for a given class
1311 // inlined_fields_id is not-nullptr for inlined fields (to get synthetic field name IDs
1312 // by using InlinedObjects::get_next_string_id()).
1313 void DumperSupport::dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* ik, uintx* inlined_fields_id) {
1314 // inlined_fields_id != nullptr means ik is a class of inlined field.
1315 // Inlined field id pointer for this class; lazyly initialized
1316 // if the class has inlined field(s) and the caller didn't provide inlined_fields_id.
1317 uintx *this_klass_inlined_fields_id = inlined_fields_id;
1318 uintx inlined_id = 0;
1319
1320 // dump the field descriptors
1321 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1322 if (!fld.access_flags().is_static()) {
1323 if (is_inlined_field(fld.field_descriptor())) {
1324 // dump "synthetic" fields for inlined fields.
1325 if (this_klass_inlined_fields_id == nullptr) {
1326 inlined_id = InlinedObjects::get_instance()->get_base_index_for(ik);
1327 this_klass_inlined_fields_id = &inlined_id;
1328 }
1329 dump_instance_field_descriptors(writer, get_inlined_field_klass(fld.field_descriptor()), this_klass_inlined_fields_id);
1330 } else {
1331 Symbol* sig = fld.signature();
1332 Symbol* name = nullptr;
1333 // Use inlined_fields_id provided by caller.
1334 if (inlined_fields_id != nullptr) {
1335 uintx name_id = InlinedObjects::get_instance()->get_next_string_id(*inlined_fields_id);
1336
1337 // name_id == 0 is returned on error. use original field signature.
1338 if (name_id != 0) {
1339 *inlined_fields_id = name_id;
1340 name = reinterpret_cast<Symbol*>(name_id);
1341 }
1342 }
1343 if (name == nullptr) {
1344 name = fld.name();
1345 }
1346
1347 writer->write_symbolID(name); // name
1348 writer->write_u1(sig2tag(sig)); // type
1349 }
1350 }
1351 }
1352 }
1353
1354 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1355 void DumperSupport::dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache) {
1356 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1357
1358 DumperClassCacheTableEntry* cache_entry = class_cache->lookup_or_create(ik);
1359
1360 u4 is = instance_size(ik, cache_entry);
1361 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1362
1363 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1364 writer->write_objectID(o);
1365 writer->write_u4(STACK_TRACE_ID);
1366
1367 // class ID
1368 writer->write_classID(ik);
1369
1370 // number of bytes that follow
1371 writer->write_u4(is);
1372
1373 // field values
1374 dump_instance_fields(writer, o, 0, class_cache, cache_entry);
1375
1376 writer->end_sub_record();
1377 }
1378
1379 // creates HPROF_GC_CLASS_DUMP record for the given instance class
1380 void DumperSupport::dump_instance_class(AbstractDumpWriter* writer, Klass* k) {
1381 InstanceKlass* ik = InstanceKlass::cast(k);
1382
1383 // We can safepoint and do a heap dump at a point where we have a Klass,
1384 // but no java mirror class has been setup for it. So we need to check
1385 // that the class is at least loaded, to avoid crash from a null mirror.
1386 if (!ik->is_loaded()) {
1387 return;
1388 }
1389
1390 u2 static_fields_count = 0;
1391 u4 static_size = get_static_fields_size(ik, static_fields_count);
1392 u2 instance_fields_count = get_instance_fields_count(ik);
1393 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1394 u4 size = checked_cast<u4>(1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size);
1395
1396 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1397
1398 // class ID
1399 writer->write_classID(ik);
1400 writer->write_u4(STACK_TRACE_ID);
1401
1402 // super class ID
1403 InstanceKlass* java_super = ik->java_super();
1404 if (java_super == nullptr) {
1405 writer->write_objectID(oop(nullptr));
1406 } else {
1407 writer->write_classID(java_super);
1408 }
1409
1410 writer->write_objectID(ik->class_loader());
1411 writer->write_objectID(ik->signers());
1412 writer->write_objectID(ik->protection_domain());
1413
1414 // reserved
1415 writer->write_objectID(oop(nullptr));
1416 writer->write_objectID(oop(nullptr));
1417
1418 // instance size
1419 writer->write_u4(HeapWordSize * ik->size_helper());
1420
1421 // size of constant pool - ignored by HAT 1.1
1422 writer->write_u2(0);
1423
1424 // static fields
1425 writer->write_u2(static_fields_count);
1426 dump_static_fields(writer, ik);
1427
1428 // description of instance fields
1429 writer->write_u2(instance_fields_count);
1430 dump_instance_field_descriptors(writer, ik);
1431
1432 writer->end_sub_record();
1433 }
1434
1435 // creates HPROF_GC_CLASS_DUMP record for the given array class
1436 void DumperSupport::dump_array_class(AbstractDumpWriter* writer, Klass* k) {
1437 InstanceKlass* ik = nullptr; // bottom class for object arrays, null for primitive type arrays
1438 if (k->is_objArray_klass()) {
1439 Klass *bk = ObjArrayKlass::cast(k)->bottom_klass();
1440 assert(bk != nullptr, "checking");
1441 if (bk->is_instance_klass()) {
1442 ik = InstanceKlass::cast(bk);
1443 }
1444 }
1445
1446 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1447 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1448 writer->write_classID(k);
1449 writer->write_u4(STACK_TRACE_ID);
1450
1451 // super class of array classes is java.lang.Object
1452 InstanceKlass* java_super = k->java_super();
1453 assert(java_super != nullptr, "checking");
1454 writer->write_classID(java_super);
1455
1456 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->class_loader());
1457 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->signers());
1458 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->protection_domain());
1459
1460 writer->write_objectID(oop(nullptr)); // reserved
1461 writer->write_objectID(oop(nullptr));
1462 writer->write_u4(0); // instance size
1463 writer->write_u2(0); // constant pool
1464 writer->write_u2(0); // static fields
1465 writer->write_u2(0); // instance fields
1466
1467 writer->end_sub_record();
1468
1469 }
1470
1471 // Hprof uses an u4 as record length field,
1472 // which means we need to truncate arrays that are too long.
1473 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size) {
1474 int length = array->length();
1475
1476 size_t length_in_bytes = (size_t)length * type_size;
1477 uint max_bytes = max_juint - header_size;
1478
1479 if (length_in_bytes > max_bytes) {
1480 length = max_bytes / type_size;
1481 length_in_bytes = (size_t)length * type_size;
1482
1483 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1484 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1485 type2name_tab[type], array->length(), length);
1486 }
1487 return length;
1488 }
1489
1490 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size) {
1491 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1492 assert((type >= T_BOOLEAN && type <= T_OBJECT) || type == T_PRIMITIVE_OBJECT, "invalid array element type");
1493 int type_size;
1494 if (type == T_OBJECT) {
1495 type_size = sizeof(address);
1496 } else if (type == T_PRIMITIVE_OBJECT) {
1497 // TODO: FIXME
1498 fatal("Not supported yet"); // FIXME: JDK-8325678
1499 } else {
1500 type_size = type2aelembytes(type);
1501 }
1502
1503 return calculate_array_max_length(writer, array, type_size, header_size);
1504 }
1505
1506 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1507 void DumperSupport::dump_object_array(AbstractDumpWriter* writer, objArrayOop array) {
1508 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1509 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1510 int length = calculate_array_max_length(writer, array, header_size);
1511 u4 size = checked_cast<u4>(header_size + length * sizeof(address));
1512
1513 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1514 writer->write_objectID(array);
1515 writer->write_u4(STACK_TRACE_ID);
1516 writer->write_u4(length);
1517
1518 // array class ID
1519 writer->write_classID(array->klass());
1520
1521 // [id]* elements
1522 for (int index = 0; index < length; index++) {
1523 oop o = array->obj_at(index);
1524 o = mask_dormant_archived_object(o, array);
1525 writer->write_objectID(o);
1526 }
1527
1528 writer->end_sub_record();
1529 }
1530
1531 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
1532 void DumperSupport::dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache) {
1533 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1534 InlineKlass* element_klass = array_klass->element_klass();
1535 int element_size = instance_size(element_klass);
1536 /* id array object ID
1537 * u4 stack trace serial number
1538 * u4 number of elements
1539 * u1 element type
1540 */
1541 short header_size = 1 + sizeof(address) + 2 * 4 + 1;
1542
1543 // TODO: use T_SHORT/T_INT/T_LONG if needed to avoid truncation
1544 BasicType type = T_BYTE;
1545 int type_size = type2aelembytes(type);
1546 int length = calculate_array_max_length(writer, array, element_size, header_size);
1547 u4 length_in_bytes = (u4)(length * element_size);
1548 u4 size = header_size + length_in_bytes;
1549
1550 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1551 writer->write_objectID(array);
1552 writer->write_u4(STACK_TRACE_ID);
1553 // TODO: round up array length for T_SHORT/T_INT/T_LONG
1554 writer->write_u4(length * element_size);
1555 writer->write_u1(type2tag(type));
1556
1557 for (int index = 0; index < length; index++) {
1558 // need offset in the holder to read inlined object. calculate it from flatArrayOop::value_at_addr()
1559 int offset = (int)((address)array->value_at_addr(index, array_klass->layout_helper())
1560 - cast_from_oop<address>(array));
1561 DumperClassCacheTableEntry* class_cache_entry = class_cache->lookup_or_create(element_klass);
1562 dump_inlined_object_fields(writer, array, offset, class_cache, class_cache_entry);
1563 }
1564
1565 // TODO: write padding bytes for T_SHORT/T_INT/T_LONG
1566
1567 InlinedObjects::get_instance()->add_flat_array(array);
1568
1569 writer->end_sub_record();
1570 }
1571
1572 #define WRITE_ARRAY(Array, Type, Size, Length) \
1573 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1574
1575 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1576 void DumperSupport::dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array) {
1577 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1578 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1579 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1580
1581 int length = calculate_array_max_length(writer, array, header_size);
1582 int type_size = type2aelembytes(type);
1583 u4 length_in_bytes = (u4)length * type_size;
1584 u4 size = header_size + length_in_bytes;
1585
1586 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1587 writer->write_objectID(array);
1588 writer->write_u4(STACK_TRACE_ID);
1589 writer->write_u4(length);
1590 writer->write_u1(type2tag(type));
1591
1592 // nothing to copy
1593 if (length == 0) {
1594 writer->end_sub_record();
1595 return;
1596 }
1597
1598 // If the byte ordering is big endian then we can copy most types directly
1599
1600 switch (type) {
1601 case T_INT : {
1602 if (Endian::is_Java_byte_ordering_different()) {
1603 WRITE_ARRAY(array, int, u4, length);
1604 } else {
1605 writer->write_raw(array->int_at_addr(0), length_in_bytes);
1606 }
1607 break;
1608 }
1609 case T_BYTE : {
1610 writer->write_raw(array->byte_at_addr(0), length_in_bytes);
1611 break;
1612 }
1613 case T_CHAR : {
1614 if (Endian::is_Java_byte_ordering_different()) {
1615 WRITE_ARRAY(array, char, u2, length);
1616 } else {
1617 writer->write_raw(array->char_at_addr(0), length_in_bytes);
1618 }
1619 break;
1620 }
1621 case T_SHORT : {
1622 if (Endian::is_Java_byte_ordering_different()) {
1623 WRITE_ARRAY(array, short, u2, length);
1624 } else {
1625 writer->write_raw(array->short_at_addr(0), length_in_bytes);
1626 }
1627 break;
1628 }
1629 case T_BOOLEAN : {
1630 if (Endian::is_Java_byte_ordering_different()) {
1631 WRITE_ARRAY(array, bool, u1, length);
1632 } else {
1633 writer->write_raw(array->bool_at_addr(0), length_in_bytes);
1634 }
1635 break;
1636 }
1637 case T_LONG : {
1638 if (Endian::is_Java_byte_ordering_different()) {
1639 WRITE_ARRAY(array, long, u8, length);
1640 } else {
1641 writer->write_raw(array->long_at_addr(0), length_in_bytes);
1642 }
1643 break;
1644 }
1645
1646 // handle float/doubles in a special value to ensure than NaNs are
1647 // written correctly. TO DO: Check if we can avoid this on processors that
1648 // use IEEE 754.
1649
1650 case T_FLOAT : {
1651 for (int i = 0; i < length; i++) {
1652 dump_float(writer, array->float_at(i));
1653 }
1654 break;
1655 }
1656 case T_DOUBLE : {
1657 for (int i = 0; i < length; i++) {
1658 dump_double(writer, array->double_at(i));
1659 }
1660 break;
1661 }
1662 default : ShouldNotReachHere();
1663 }
1664
1665 writer->end_sub_record();
1666 }
1667
1668 // create a HPROF_FRAME record of the given Method* and bci
1669 void DumperSupport::dump_stack_frame(AbstractDumpWriter* writer,
1670 int frame_serial_num,
1671 int class_serial_num,
1672 Method* m,
1673 int bci) {
1674 int line_number;
1675 if (m->is_native()) {
1676 line_number = -3; // native frame
1677 } else {
1678 line_number = m->line_number_from_bci(bci);
1679 }
1680
1681 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1682 writer->write_id(frame_serial_num); // frame serial number
1683 writer->write_symbolID(m->name()); // method's name
1684 writer->write_symbolID(m->signature()); // method's signature
1685
1686 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1687 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1688 writer->write_u4(class_serial_num); // class serial number
1689 writer->write_u4((u4) line_number); // line number
1690 }
1691
1692
1693 class InlinedFieldNameDumper : public LockedClassesDo {
1694 public:
1695 typedef void (*Callback)(InlinedObjects *owner, const Klass *klass, uintx base_index, int count);
1696
1697 private:
1698 AbstractDumpWriter* _writer;
1699 InlinedObjects *_owner;
1700 Callback _callback;
1701 uintx _index;
1702
1703 void dump_inlined_field_names(GrowableArray<Symbol*>* super_names, Symbol* field_name, InlineKlass* klass) {
1704 super_names->push(field_name);
1705 for (HierarchicalFieldStream<JavaFieldStream> fld(klass); !fld.done(); fld.next()) {
1706 if (!fld.access_flags().is_static()) {
1707 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1708 dump_inlined_field_names(super_names, fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1709 } else {
1710 // get next string ID.
1711 uintx next_index = _owner->get_next_string_id(_index);
1712 if (next_index == 0) {
1713 // something went wrong (overflow?)
1714 // stop generation; the rest of inlined objects will have original field names.
1715 return;
1716 }
1717 _index = next_index;
1718
1719 // Calculate length.
1720 int len = fld.name()->utf8_length();
1721 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1722 len += (*it)->utf8_length() + 1; // +1 for ".".
1723 }
1724
1725 DumperSupport::write_header(_writer, HPROF_UTF8, oopSize + len);
1726 _writer->write_symbolID(reinterpret_cast<Symbol*>(_index));
1727 // Write the string value.
1728 // 1) super_names.
1729 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1730 _writer->write_raw((*it)->bytes(), (*it)->utf8_length());
1731 _writer->write_u1('.');
1732 }
1733 // 2) field name.
1734 _writer->write_raw(fld.name()->bytes(), fld.name()->utf8_length());
1735 }
1736 }
1737 }
1738 super_names->pop();
1739 }
1740
1741 void dump_inlined_field_names(Symbol* field_name, InlineKlass* field_klass) {
1742 GrowableArray<Symbol*> super_names(4, mtServiceability);
1743 dump_inlined_field_names(&super_names, field_name, field_klass);
1744 }
1745
1746 public:
1747 InlinedFieldNameDumper(AbstractDumpWriter* writer, InlinedObjects* owner, Callback callback)
1748 : _writer(writer), _owner(owner), _callback(callback), _index(0) {
1749 }
1750
1751 void do_klass(Klass* k) {
1752 if (!k->is_instance_klass()) {
1753 return;
1754 }
1755 InstanceKlass* ik = InstanceKlass::cast(k);
1756 // if (ik->has_inline_type_fields()) {
1757 // return;
1758 // }
1759
1760 uintx base_index = _index;
1761 int count = 0;
1762
1763 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1764 if (!fld.access_flags().is_static()) {
1765 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1766 dump_inlined_field_names(fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1767 count++;
1768 }
1769 }
1770 }
1771
1772 if (count != 0) {
1773 _callback(_owner, k, base_index, count);
1774 }
1775 }
1776 };
1777
1778 class InlinedFieldsDumper : public LockedClassesDo {
1779 private:
1780 AbstractDumpWriter* _writer;
1781
1782 public:
1783 InlinedFieldsDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1784
1785 void do_klass(Klass* k) {
1786 if (!k->is_instance_klass()) {
1787 return;
1788 }
1789 InstanceKlass* ik = InstanceKlass::cast(k);
1790 // if (ik->has_inline_type_fields()) {
1791 // return;
1792 // }
1793
1794 // We can be at a point where java mirror does not exist yet.
1795 // So we need to check that the class is at least loaded, to avoid crash from a null mirror.
1796 if (!ik->is_loaded()) {
1797 return;
1798 }
1799
1800 u2 inlined_count = 0;
1801 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1802 if (!fld.access_flags().is_static()) {
1803 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1804 inlined_count++;
1805 }
1806 }
1807 }
1808 if (inlined_count != 0) {
1809 _writer->write_u1(HPROF_CLASS_WITH_INLINED_FIELDS);
1810
1811 // class ID
1812 _writer->write_classID(ik);
1813 // number of inlined fields
1814 _writer->write_u2(inlined_count);
1815 u2 index = 0;
1816 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1817 if (!fld.access_flags().is_static()) {
1818 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1819 // inlined field index
1820 _writer->write_u2(index);
1821 // synthetic field count
1822 u2 field_count = DumperSupport::get_instance_fields_count(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1823 _writer->write_u2(field_count);
1824 // original field name
1825 _writer->write_symbolID(fld.name());
1826 // inlined field class ID
1827 _writer->write_classID(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1828
1829 index += field_count;
1830 } else {
1831 index++;
1832 }
1833 }
1834 }
1835 }
1836 }
1837 };
1838
1839
1840 void InlinedObjects::init() {
1841 _instance = this;
1842
1843 struct Closure : public SymbolClosure {
1844 uintx _min_id = max_uintx;
1845 uintx _max_id = 0;
1846 Closure() : _min_id(max_uintx), _max_id(0) {}
1847
1848 void do_symbol(Symbol** p) {
1849 uintx val = reinterpret_cast<uintx>(*p);
1850 if (val < _min_id) {
1851 _min_id = val;
1852 }
1853 if (val > _max_id) {
1854 _max_id = val;
1855 }
1856 }
1857 } closure;
1858
1859 SymbolTable::symbols_do(&closure);
1860
1861 _min_string_id = closure._min_id;
1862 _max_string_id = closure._max_id;
1863 }
1864
1865 void InlinedObjects::release() {
1866 _instance = nullptr;
1867
1868 if (_inlined_field_map != nullptr) {
1869 delete _inlined_field_map;
1870 _inlined_field_map = nullptr;
1871 }
1872 if (_flat_arrays != nullptr) {
1873 delete _flat_arrays;
1874 _flat_arrays = nullptr;
1875 }
1876 }
1877
1878 void InlinedObjects::inlined_field_names_callback(InlinedObjects* _this, const Klass* klass, uintx base_index, int count) {
1879 if (_this->_inlined_field_map == nullptr) {
1880 _this->_inlined_field_map = new (mtServiceability) GrowableArray<ClassInlinedFields>(100, mtServiceability);
1881 }
1882 _this->_inlined_field_map->append(ClassInlinedFields(klass, base_index));
1883
1884 // counters for dumping classes with inlined fields
1885 _this->_classes_count++;
1886 _this->_inlined_fields_count += count;
1887 }
1888
1889 void InlinedObjects::dump_inlined_field_names(AbstractDumpWriter* writer) {
1890 InlinedFieldNameDumper nameDumper(writer, this, inlined_field_names_callback);
1891 ClassLoaderDataGraph::classes_do(&nameDumper);
1892
1893 if (_inlined_field_map != nullptr) {
1894 // prepare the map for get_base_index_for().
1895 _inlined_field_map->sort(ClassInlinedFields::compare);
1896 }
1897 }
1898
1899 uintx InlinedObjects::get_base_index_for(Klass* k) {
1900 if (_inlined_field_map != nullptr) {
1901 bool found = false;
1902 int idx = _inlined_field_map->find_sorted<ClassInlinedFields, ClassInlinedFields::compare>(ClassInlinedFields(k, 0), found);
1903 if (found) {
1904 return _inlined_field_map->at(idx).base_index;
1905 }
1906 }
1907
1908 // return max_uintx, so get_next_string_id returns 0.
1909 return max_uintx;
1910 }
1911
1912 uintx InlinedObjects::get_next_string_id(uintx id) {
1913 if (++id == _min_string_id) {
1914 return _max_string_id + 1;
1915 }
1916 return id;
1917 }
1918
1919 void InlinedObjects::dump_classed_with_inlined_fields(AbstractDumpWriter* writer) {
1920 if (_classes_count != 0) {
1921 // Record for each class contains tag(u1), class ID and count(u2)
1922 // for each inlined field index(u2), synthetic fields count(u2), original field name and class ID
1923 int size = _classes_count * (1 + sizeof(address) + 2)
1924 + _inlined_fields_count * (2 + 2 + sizeof(address) + sizeof(address));
1925 DumperSupport::write_header(writer, HPROF_INLINED_FIELDS, (u4)size);
1926
1927 InlinedFieldsDumper dumper(writer);
1928 ClassLoaderDataGraph::classes_do(&dumper);
1929 }
1930 }
1931
1932 void InlinedObjects::add_flat_array(oop array) {
1933 if (_flat_arrays == nullptr) {
1934 _flat_arrays = new (mtServiceability) GrowableArray<oop>(100, mtServiceability);
1935 }
1936 _flat_arrays->append(array);
1937 }
1938
1939 void InlinedObjects::dump_flat_arrays(AbstractDumpWriter* writer) {
1940 if (_flat_arrays != nullptr) {
1941 // For each flat array the record contains tag (u1), object ID and class ID.
1942 int size = _flat_arrays->length() * (1 + sizeof(address) + sizeof(address));
1943
1944 DumperSupport::write_header(writer, HPROF_FLAT_ARRAYS, (u4)size);
1945 for (GrowableArrayIterator<oop> it = _flat_arrays->begin(); it != _flat_arrays->end(); ++it) {
1946 flatArrayOop array = flatArrayOop(*it);
1947 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1948 InlineKlass* element_klass = array_klass->element_klass();
1949 writer->write_u1(HPROF_FLAT_ARRAY);
1950 writer->write_objectID(array);
1951 writer->write_classID(element_klass);
1952 }
1953 }
1954 }
1955
1956
1957 // Support class used to generate HPROF_UTF8 records from the entries in the
1958 // SymbolTable.
1959
1960 class SymbolTableDumper : public SymbolClosure {
1961 private:
1962 AbstractDumpWriter* _writer;
1963 AbstractDumpWriter* writer() const { return _writer; }
1964 public:
1965 SymbolTableDumper(AbstractDumpWriter* writer) { _writer = writer; }
1966 void do_symbol(Symbol** p);
1967 };
1968
1969 void SymbolTableDumper::do_symbol(Symbol** p) {
1970 ResourceMark rm;
1971 Symbol* sym = *p;
1972 int len = sym->utf8_length();
1973 if (len > 0) {
1974 char* s = sym->as_utf8();
1975 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1976 writer()->write_symbolID(sym);
1977 writer()->write_raw(s, len);
1978 }
1979 }
1980
1981 // Support class used to generate HPROF_GC_CLASS_DUMP records
1982
1983 class ClassDumper : public KlassClosure {
1984 private:
1985 AbstractDumpWriter* _writer;
1986 AbstractDumpWriter* writer() const { return _writer; }
1987
1988 public:
1989 ClassDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1990
1991 void do_klass(Klass* k) {
1992 if (k->is_instance_klass()) {
1993 DumperSupport::dump_instance_class(writer(), k);
1994 } else {
1995 DumperSupport::dump_array_class(writer(), k);
1996 }
1997 }
1998 };
1999
2000 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
2001
2002 class JNILocalsDumper : public OopClosure {
2003 private:
2004 AbstractDumpWriter* _writer;
2005 u4 _thread_serial_num;
2006 int _frame_num;
2007 AbstractDumpWriter* writer() const { return _writer; }
2008 public:
2009 JNILocalsDumper(AbstractDumpWriter* writer, u4 thread_serial_num) {
2010 _writer = writer;
2011 _thread_serial_num = thread_serial_num;
2012 _frame_num = -1; // default - empty stack
2013 }
2014 void set_frame_number(int n) { _frame_num = n; }
2015 void do_oop(oop* obj_p);
2016 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2017 };
2018
2019 void JNILocalsDumper::do_oop(oop* obj_p) {
2020 // ignore null handles
2021 oop o = *obj_p;
2022 if (o != nullptr) {
2023 u4 size = 1 + sizeof(address) + 4 + 4;
2024 writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
2025 writer()->write_objectID(o);
2026 writer()->write_u4(_thread_serial_num);
2027 writer()->write_u4((u4)_frame_num);
2028 writer()->end_sub_record();
2029 }
2030 }
2031
2032
2033 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
2034
2035 class JNIGlobalsDumper : public OopClosure {
2036 private:
2037 AbstractDumpWriter* _writer;
2038 AbstractDumpWriter* writer() const { return _writer; }
2039
2040 public:
2041 JNIGlobalsDumper(AbstractDumpWriter* writer) {
2042 _writer = writer;
2043 }
2044 void do_oop(oop* obj_p);
2045 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2046 };
2047
2048 void JNIGlobalsDumper::do_oop(oop* obj_p) {
2049 oop o = NativeAccess<AS_NO_KEEPALIVE>::oop_load(obj_p);
2050
2051 // ignore these
2052 if (o == nullptr) return;
2053 // we ignore global ref to symbols and other internal objects
2054 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
2055 u4 size = 1 + 2 * sizeof(address);
2056 writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
2057 writer()->write_objectID(o);
2058 writer()->write_rootID(obj_p); // global ref ID
2059 writer()->end_sub_record();
2060 }
2061 };
2062
2063 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
2064
2065 class StickyClassDumper : public KlassClosure {
2066 private:
2067 AbstractDumpWriter* _writer;
2068 AbstractDumpWriter* writer() const { return _writer; }
2069 public:
2070 StickyClassDumper(AbstractDumpWriter* writer) {
2071 _writer = writer;
2072 }
2073 void do_klass(Klass* k) {
2074 if (k->is_instance_klass()) {
2075 InstanceKlass* ik = InstanceKlass::cast(k);
2076 u4 size = 1 + sizeof(address);
2077 writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
2078 writer()->write_classID(ik);
2079 writer()->end_sub_record();
2080 }
2081 }
2082 };
2083
2084 // Support class used to generate HPROF_GC_ROOT_JAVA_FRAME records.
2085
2086 class JavaStackRefDumper : public StackObj {
2087 private:
2088 AbstractDumpWriter* _writer;
2089 u4 _thread_serial_num;
2090 int _frame_num;
2091 AbstractDumpWriter* writer() const { return _writer; }
2092 public:
2093 JavaStackRefDumper(AbstractDumpWriter* writer, u4 thread_serial_num)
2094 : _writer(writer), _thread_serial_num(thread_serial_num), _frame_num(-1) // default - empty stack
2095 {
2096 }
2097
2098 void set_frame_number(int n) { _frame_num = n; }
2099
2100 void dump_java_stack_refs(StackValueCollection* values);
2101 };
2102
2103 void JavaStackRefDumper::dump_java_stack_refs(StackValueCollection* values) {
2104 for (int index = 0; index < values->size(); index++) {
2105 if (values->at(index)->type() == T_OBJECT) {
2106 oop o = values->obj_at(index)();
2107 if (o != nullptr) {
2108 u4 size = 1 + sizeof(address) + 4 + 4;
2109 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
2110 writer()->write_objectID(o);
2111 writer()->write_u4(_thread_serial_num);
2112 writer()->write_u4((u4)_frame_num);
2113 writer()->end_sub_record();
2114 }
2115 }
2116 }
2117 }
2118
2119 // Class to collect, store and dump thread-related data:
2120 // - HPROF_TRACE and HPROF_FRAME records;
2121 // - HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecords.
2122 class ThreadDumper : public CHeapObj<mtInternal> {
2123 public:
2124 enum class ThreadType { Platform, MountedVirtual, UnmountedVirtual };
2125
2126 private:
2127 ThreadType _thread_type;
2128 JavaThread* _java_thread;
2129 oop _thread_oop;
2130
2131 GrowableArray<StackFrameInfo*>* _frames;
2132 // non-null if the thread is OOM thread
2133 Method* _oome_constructor;
2134 int _thread_serial_num;
2135 int _start_frame_serial_num;
2136
2137 vframe* get_top_frame() const;
2138
2139 public:
2140 static bool should_dump_pthread(JavaThread* thread) {
2141 return thread->threadObj() != nullptr && !thread->is_exiting() && !thread->is_hidden_from_external_view();
2142 }
2143
2144 static bool should_dump_vthread(oop vt) {
2145 return java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::NEW
2146 && java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::TERMINATED;
2147 }
2148
2149 static bool is_vthread_mounted(oop vt) {
2150 // The code should be consistent with the "mounted virtual thread" case
2151 // (VM_HeapDumper::dump_stack_traces(), ThreadDumper::get_top_frame()).
2152 // I.e. virtual thread is mounted if its carrierThread is not null
2153 // and is_vthread_mounted() for the carrier thread returns true.
2154 oop carrier_thread = java_lang_VirtualThread::carrier_thread(vt);
2155 if (carrier_thread == nullptr) {
2156 return false;
2157 }
2158 JavaThread* java_thread = java_lang_Thread::thread(carrier_thread);
2159 return java_thread->is_vthread_mounted();
2160 }
2161
2162 ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop);
2163
2164 // affects frame_count
2165 void add_oom_frame(Method* oome_constructor) {
2166 assert(_start_frame_serial_num == 0, "add_oom_frame cannot be called after init_serial_nums");
2167 _oome_constructor = oome_constructor;
2168 }
2169
2170 void init_serial_nums(volatile int* thread_counter, volatile int* frame_counter) {
2171 assert(_start_frame_serial_num == 0, "already initialized");
2172 _thread_serial_num = Atomic::fetch_then_add(thread_counter, 1);
2173 _start_frame_serial_num = Atomic::fetch_then_add(frame_counter, frame_count());
2174 }
2175
2176 bool oom_thread() const {
2177 return _oome_constructor != nullptr;
2178 }
2179
2180 int frame_count() const {
2181 return _frames->length() + (oom_thread() ? 1 : 0);
2182 }
2183
2184 u4 thread_serial_num() const {
2185 return (u4)_thread_serial_num;
2186 }
2187
2188 u4 stack_trace_serial_num() const {
2189 return (u4)(_thread_serial_num + STACK_TRACE_ID);
2190 }
2191
2192 // writes HPROF_TRACE and HPROF_FRAME records
2193 // returns number of dumped frames
2194 void dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map);
2195
2196 // writes HPROF_GC_ROOT_THREAD_OBJ subrecord
2197 void dump_thread_obj(AbstractDumpWriter* writer);
2198
2199 // Walk the stack of the thread.
2200 // Dumps a HPROF_GC_ROOT_JAVA_FRAME subrecord for each local
2201 // Dumps a HPROF_GC_ROOT_JNI_LOCAL subrecord for each JNI local
2202 void dump_stack_refs(AbstractDumpWriter* writer);
2203
2204 };
2205
2206 ThreadDumper::ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop)
2207 : _thread_type(thread_type), _java_thread(java_thread), _thread_oop(thread_oop),
2208 _oome_constructor(nullptr),
2209 _thread_serial_num(0), _start_frame_serial_num(0)
2210 {
2211 // sanity checks
2212 if (_thread_type == ThreadType::UnmountedVirtual) {
2213 assert(_java_thread == nullptr, "sanity");
2214 assert(_thread_oop != nullptr, "sanity");
2215 } else {
2216 assert(_java_thread != nullptr, "sanity");
2217 assert(_thread_oop != nullptr, "sanity");
2218 }
2219
2220 _frames = new (mtServiceability) GrowableArray<StackFrameInfo*>(10, mtServiceability);
2221 bool stop_at_vthread_entry = _thread_type == ThreadType::MountedVirtual;
2222
2223 // vframes are resource allocated
2224 Thread* current_thread = Thread::current();
2225 ResourceMark rm(current_thread);
2226 HandleMark hm(current_thread);
2227
2228 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2229 if (stop_at_vthread_entry && vf->is_vthread_entry()) {
2230 break;
2231 }
2232 if (vf->is_java_frame()) {
2233 javaVFrame* jvf = javaVFrame::cast(vf);
2234 _frames->append(new StackFrameInfo(jvf, false));
2235 } else {
2236 // ignore non-Java frames
2237 }
2238 }
2239 }
2240
2241 void ThreadDumper::dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map) {
2242 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_nums are not initialized");
2243
2244 // write HPROF_FRAME records for this thread's stack trace
2245 int depth = _frames->length();
2246 int frame_serial_num = _start_frame_serial_num;
2247
2248 if (oom_thread()) {
2249 // OOM thread
2250 // write fake frame that makes it look like the thread, which caused OOME,
2251 // is in the OutOfMemoryError zero-parameter constructor
2252 int oome_serial_num = klass_map->find(_oome_constructor->method_holder());
2253 // the class serial number starts from 1
2254 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
2255 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, oome_serial_num, _oome_constructor, 0);
2256 depth++;
2257 }
2258
2259 for (int j = 0; j < _frames->length(); j++) {
2260 StackFrameInfo* frame = _frames->at(j);
2261 Method* m = frame->method();
2262 int class_serial_num = klass_map->find(m->method_holder());
2263 // the class serial number starts from 1
2264 assert(class_serial_num > 0, "class not found");
2265 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, class_serial_num, m, frame->bci());
2266 }
2267
2268 // write HPROF_TRACE record for the thread
2269 DumperSupport::write_header(writer, HPROF_TRACE, checked_cast<u4>(3 * sizeof(u4) + depth * oopSize));
2270 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2271 writer->write_u4(thread_serial_num()); // thread serial number
2272 writer->write_u4((u4)depth); // frame count (including oom frame)
2273 for (int j = 1; j <= depth; j++) {
2274 writer->write_id(_start_frame_serial_num + j);
2275 }
2276 }
2277
2278 void ThreadDumper::dump_thread_obj(AbstractDumpWriter * writer) {
2279 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2280
2281 u4 size = 1 + sizeof(address) + 4 + 4;
2282 writer->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
2283 writer->write_objectID(_thread_oop);
2284 writer->write_u4(thread_serial_num()); // thread serial number
2285 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2286 writer->end_sub_record();
2287 }
2288
2289 void ThreadDumper::dump_stack_refs(AbstractDumpWriter * writer) {
2290 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2291
2292 JNILocalsDumper blk(writer, thread_serial_num());
2293 if (_thread_type == ThreadType::Platform) {
2294 if (!_java_thread->has_last_Java_frame()) {
2295 // no last java frame but there may be JNI locals
2296 _java_thread->active_handles()->oops_do(&blk);
2297 return;
2298 }
2299 }
2300
2301 JavaStackRefDumper java_ref_dumper(writer, thread_serial_num());
2302
2303 // vframes are resource allocated
2304 Thread* current_thread = Thread::current();
2305 ResourceMark rm(current_thread);
2306 HandleMark hm(current_thread);
2307
2308 bool stopAtVthreadEntry = _thread_type == ThreadType::MountedVirtual;
2309 frame* last_entry_frame = nullptr;
2310 bool is_top_frame = true;
2311 int depth = 0;
2312 if (oom_thread()) {
2313 depth++;
2314 }
2315
2316 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2317 if (stopAtVthreadEntry && vf->is_vthread_entry()) {
2318 break;
2319 }
2320
2321 if (vf->is_java_frame()) {
2322 javaVFrame* jvf = javaVFrame::cast(vf);
2323 if (!(jvf->method()->is_native())) {
2324 java_ref_dumper.set_frame_number(depth);
2325 java_ref_dumper.dump_java_stack_refs(jvf->locals());
2326 java_ref_dumper.dump_java_stack_refs(jvf->expressions());
2327 } else {
2328 // native frame
2329 blk.set_frame_number(depth);
2330 if (is_top_frame) {
2331 // JNI locals for the top frame.
2332 assert(_java_thread != nullptr, "impossible for unmounted vthread");
2333 _java_thread->active_handles()->oops_do(&blk);
2334 } else {
2335 if (last_entry_frame != nullptr) {
2336 // JNI locals for the entry frame
2337 assert(last_entry_frame->is_entry_frame(), "checking");
2338 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
2339 }
2340 }
2341 }
2342 last_entry_frame = nullptr;
2343 // increment only for Java frames
2344 depth++;
2345 } else {
2346 // externalVFrame - for an entry frame then we report the JNI locals
2347 // when we find the corresponding javaVFrame
2348 frame* fr = vf->frame_pointer();
2349 assert(fr != nullptr, "sanity check");
2350 if (fr->is_entry_frame()) {
2351 last_entry_frame = fr;
2352 }
2353 }
2354 is_top_frame = false;
2355 }
2356 assert(depth == frame_count(), "total number of Java frames not matched");
2357 }
2358
2359 vframe* ThreadDumper::get_top_frame() const {
2360 if (_thread_type == ThreadType::UnmountedVirtual) {
2361 ContinuationWrapper cont(java_lang_VirtualThread::continuation(_thread_oop));
2362 if (cont.is_empty()) {
2363 return nullptr;
2364 }
2365 assert(!cont.is_mounted(), "sanity check");
2366 stackChunkOop chunk = cont.last_nonempty_chunk();
2367 if (chunk == nullptr || chunk->is_empty()) {
2368 return nullptr;
2369 }
2370
2371 RegisterMap reg_map(cont.continuation(), RegisterMap::UpdateMap::include);
2372 frame fr = chunk->top_frame(®_map);
2373 vframe* vf = vframe::new_vframe(&fr, ®_map, nullptr); // don't need JavaThread
2374 return vf;
2375 }
2376
2377 RegisterMap reg_map(_java_thread,
2378 RegisterMap::UpdateMap::include,
2379 RegisterMap::ProcessFrames::include,
2380 RegisterMap::WalkContinuation::skip);
2381 switch (_thread_type) {
2382 case ThreadType::Platform:
2383 if (!_java_thread->has_last_Java_frame()) {
2384 return nullptr;
2385 }
2386 return _java_thread->is_vthread_mounted()
2387 ? _java_thread->carrier_last_java_vframe(®_map)
2388 : _java_thread->platform_thread_last_java_vframe(®_map);
2389
2390 case ThreadType::MountedVirtual:
2391 return _java_thread->last_java_vframe(®_map);
2392
2393 default: // make compilers happy
2394 break;
2395 }
2396 ShouldNotReachHere();
2397 return nullptr;
2398 }
2399
2400 // Callback to dump thread-related data for unmounted virtual threads;
2401 // implemented by VM_HeapDumper.
2402 class UnmountedVThreadDumper {
2403 public:
2404 virtual void dump_vthread(oop vt, AbstractDumpWriter* segment_writer) = 0;
2405 };
2406
2407 // Support class used when iterating over the heap.
2408 class HeapObjectDumper : public ObjectClosure {
2409 private:
2410 AbstractDumpWriter* _writer;
2411 AbstractDumpWriter* writer() { return _writer; }
2412 UnmountedVThreadDumper* _vthread_dumper;
2413
2414 DumperClassCacheTable _class_cache;
2415
2416 public:
2417 HeapObjectDumper(AbstractDumpWriter* writer, UnmountedVThreadDumper* vthread_dumper)
2418 : _writer(writer), _vthread_dumper(vthread_dumper) {}
2419
2420 // called for each object in the heap
2421 void do_object(oop o);
2422 };
2423
2424 void HeapObjectDumper::do_object(oop o) {
2425 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
2426 if (o->klass() == vmClasses::Class_klass()) {
2427 if (!java_lang_Class::is_primitive(o)) {
2428 return;
2429 }
2430 }
2431
2432 if (DumperSupport::mask_dormant_archived_object(o, nullptr) == nullptr) {
2433 return;
2434 }
2435
2436 if (o->is_instance()) {
2437 // create a HPROF_GC_INSTANCE record for each object
2438 DumperSupport::dump_instance(writer(), o, &_class_cache);
2439 // If we encounter an unmounted virtual thread it needs to be dumped explicitly
2440 // (mounted virtual threads are dumped with their carriers).
2441 if (java_lang_VirtualThread::is_instance(o)
2442 && ThreadDumper::should_dump_vthread(o) && !ThreadDumper::is_vthread_mounted(o)) {
2443 _vthread_dumper->dump_vthread(o, writer());
2444 }
2445 } else if (o->is_objArray()) {
2446 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
2447 DumperSupport::dump_object_array(writer(), objArrayOop(o));
2448 } else if (o->is_flatArray()) {
2449 DumperSupport::dump_flat_array(writer(), flatArrayOop(o), &_class_cache);
2450 } else if (o->is_typeArray()) {
2451 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
2452 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
2453 }
2454 }
2455
2456 // The dumper controller for parallel heap dump
2457 class DumperController : public CHeapObj<mtInternal> {
2458 private:
2459 Monitor* _lock;
2460 Mutex* _global_writer_lock;
2461
2462 const uint _dumper_number;
2463 uint _complete_number;
2464
2465 bool _started; // VM dumper started and acquired global writer lock
2466
2467 public:
2468 DumperController(uint number) :
2469 // _lock and _global_writer_lock are used for synchronization between GC worker threads inside safepoint,
2470 // so we lock with _no_safepoint_check_flag.
2471 // signal_start() acquires _lock when global writer is locked,
2472 // its rank must be less than _global_writer_lock rank.
2473 _lock(new (std::nothrow) PaddedMonitor(Mutex::nosafepoint - 1, "DumperController_lock")),
2474 _global_writer_lock(new (std::nothrow) Mutex(Mutex::nosafepoint, "DumpWriter_lock")),
2475 _dumper_number(number),
2476 _complete_number(0),
2477 _started(false)
2478 {}
2479
2480 ~DumperController() {
2481 delete _lock;
2482 delete _global_writer_lock;
2483 }
2484
2485 // parallel (non VM) dumpers must wait until VM dumper acquires global writer lock
2486 void wait_for_start_signal() {
2487 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2488 while (_started == false) {
2489 ml.wait();
2490 }
2491 }
2492
2493 void signal_start() {
2494 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2495 _started = true;
2496 ml.notify_all();
2497 }
2498
2499 void lock_global_writer() {
2500 _global_writer_lock->lock_without_safepoint_check();
2501 }
2502
2503 void unlock_global_writer() {
2504 _global_writer_lock->unlock();
2505 }
2506
2507 void dumper_complete(DumpWriter* local_writer, DumpWriter* global_writer) {
2508 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2509 _complete_number++;
2510 // propagate local error to global if any
2511 if (local_writer->has_error()) {
2512 global_writer->set_error(local_writer->error());
2513 }
2514 ml.notify();
2515 }
2516
2517 void wait_all_dumpers_complete() {
2518 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2519 while (_complete_number != _dumper_number) {
2520 ml.wait();
2521 }
2522 }
2523 };
2524
2525 // DumpMerger merges separate dump files into a complete one
2526 class DumpMerger : public StackObj {
2527 private:
2528 DumpWriter* _writer;
2529 InlinedObjects* _inlined_objects;
2530 const char* _path;
2531 bool _has_error;
2532 int _dump_seq;
2533
2534 private:
2535 void merge_file(const char* path);
2536 void merge_done();
2537 void set_error(const char* msg);
2538
2539 public:
2540 DumpMerger(const char* path, DumpWriter* writer, InlinedObjects* inlined_objects, int dump_seq) :
2541 _writer(writer),
2542 _inlined_objects(inlined_objects),
2543 _path(path),
2544 _has_error(_writer->has_error()),
2545 _dump_seq(dump_seq) {}
2546
2547 void do_merge();
2548
2549 // returns path for the parallel DumpWriter (resource allocated)
2550 static char* get_writer_path(const char* base_path, int seq);
2551
2552 };
2553
2554 char* DumpMerger::get_writer_path(const char* base_path, int seq) {
2555 // approximate required buffer size
2556 size_t buf_size = strlen(base_path)
2557 + 2 // ".p"
2558 + 10 // number (that's enough for 2^32 parallel dumpers)
2559 + 1; // '\0'
2560
2561 char* path = NEW_RESOURCE_ARRAY(char, buf_size);
2562 memset(path, 0, buf_size);
2563
2564 os::snprintf(path, buf_size, "%s.p%d", base_path, seq);
2565
2566 return path;
2567 }
2568
2569
2570 void DumpMerger::merge_done() {
2571 // Writes the HPROF_HEAP_DUMP_END record.
2572 if (!_has_error) {
2573 DumperSupport::end_of_dump(_writer);
2574 _inlined_objects->dump_flat_arrays(_writer);
2575 _writer->flush();
2576 _inlined_objects->release();
2577 }
2578 _dump_seq = 0; //reset
2579 }
2580
2581 void DumpMerger::set_error(const char* msg) {
2582 assert(msg != nullptr, "sanity check");
2583 log_error(heapdump)("%s (file: %s)", msg, _path);
2584 _writer->set_error(msg);
2585 _has_error = true;
2586 }
2587
2588 #ifdef LINUX
2589 // Merge segmented heap files via sendfile, it's more efficient than the
2590 // read+write combination, which would require transferring data to and from
2591 // user space.
2592 void DumpMerger::merge_file(const char* path) {
2593 TraceTime timer("Merge segmented heap file directly", TRACETIME_LOG(Info, heapdump));
2594
2595 int segment_fd = os::open(path, O_RDONLY, 0);
2596 if (segment_fd == -1) {
2597 set_error("Can not open segmented heap file during merging");
2598 return;
2599 }
2600
2601 struct stat st;
2602 if (os::stat(path, &st) != 0) {
2603 ::close(segment_fd);
2604 set_error("Can not get segmented heap file size during merging");
2605 return;
2606 }
2607
2608 // A successful call to sendfile may write fewer bytes than requested; the
2609 // caller should be prepared to retry the call if there were unsent bytes.
2610 jlong offset = 0;
2611 while (offset < st.st_size) {
2612 int ret = os::Linux::sendfile(_writer->get_fd(), segment_fd, &offset, st.st_size);
2613 if (ret == -1) {
2614 ::close(segment_fd);
2615 set_error("Failed to merge segmented heap file");
2616 return;
2617 }
2618 }
2619
2620 // As sendfile variant does not call the write method of the global writer,
2621 // bytes_written is also incorrect for this variant, we need to explicitly
2622 // accumulate bytes_written for the global writer in this case
2623 julong accum = _writer->bytes_written() + st.st_size;
2624 _writer->set_bytes_written(accum);
2625 ::close(segment_fd);
2626 }
2627 #else
2628 // Generic implementation using read+write
2629 void DumpMerger::merge_file(const char* path) {
2630 TraceTime timer("Merge segmented heap file", TRACETIME_LOG(Info, heapdump));
2631
2632 fileStream segment_fs(path, "rb");
2633 if (!segment_fs.is_open()) {
2634 set_error("Can not open segmented heap file during merging");
2635 return;
2636 }
2637
2638 jlong total = 0;
2639 size_t cnt = 0;
2640
2641 // Use _writer buffer for reading.
2642 while ((cnt = segment_fs.read(_writer->buffer(), 1, _writer->buffer_size())) != 0) {
2643 _writer->set_position(cnt);
2644 _writer->flush();
2645 total += cnt;
2646 }
2647
2648 if (segment_fs.fileSize() != total) {
2649 set_error("Merged heap dump is incomplete");
2650 }
2651 }
2652 #endif
2653
2654 void DumpMerger::do_merge() {
2655 TraceTime timer("Merge heap files complete", TRACETIME_LOG(Info, heapdump));
2656
2657 // Since contents in segmented heap file were already zipped, we don't need to zip
2658 // them again during merging.
2659 AbstractCompressor* saved_compressor = _writer->compressor();
2660 _writer->set_compressor(nullptr);
2661
2662 // Merge the content of the remaining files into base file. Regardless of whether
2663 // the merge process is successful or not, these segmented files will be deleted.
2664 for (int i = 0; i < _dump_seq; i++) {
2665 ResourceMark rm;
2666 const char* path = get_writer_path(_path, i);
2667 if (!_has_error) {
2668 merge_file(path);
2669 }
2670 // Delete selected segmented heap file nevertheless
2671 if (remove(path) != 0) {
2672 log_info(heapdump)("Removal of segment file (%d) failed (%d)", i, errno);
2673 }
2674 }
2675
2676 // restore compressor for further use
2677 _writer->set_compressor(saved_compressor);
2678 merge_done();
2679 }
2680
2681 // The VM operation that performs the heap dump
2682 class VM_HeapDumper : public VM_GC_Operation, public WorkerTask, public UnmountedVThreadDumper {
2683 private:
2684 static VM_HeapDumper* _global_dumper;
2685 static DumpWriter* _global_writer;
2686 DumpWriter* _local_writer;
2687 JavaThread* _oome_thread;
2688 Method* _oome_constructor;
2689 bool _gc_before_heap_dump;
2690 GrowableArray<Klass*>* _klass_map;
2691
2692 ThreadDumper** _thread_dumpers; // platform, carrier and mounted virtual threads
2693 int _thread_dumpers_count;
2694 volatile int _thread_serial_num;
2695 volatile int _frame_serial_num;
2696
2697 volatile int _dump_seq;
2698
2699 // Inlined object support.
2700 InlinedObjects _inlined_objects;
2701
2702 // parallel heap dump support
2703 uint _num_dumper_threads;
2704 DumperController* _dumper_controller;
2705 ParallelObjectIterator* _poi;
2706
2707 // Dumper id of VMDumper thread.
2708 static const int VMDumperId = 0;
2709 // VM dumper dumps both heap and non-heap data, other dumpers dump heap-only data.
2710 static bool is_vm_dumper(int dumper_id) { return dumper_id == VMDumperId; }
2711 // the 1st dumper calling get_next_dumper_id becomes VM dumper
2712 int get_next_dumper_id() {
2713 return Atomic::fetch_then_add(&_dump_seq, 1);
2714 }
2715
2716 // accessors and setters
2717 static VM_HeapDumper* dumper() { assert(_global_dumper != nullptr, "Error"); return _global_dumper; }
2718 static DumpWriter* writer() { assert(_global_writer != nullptr, "Error"); return _global_writer; }
2719
2720 void set_global_dumper() {
2721 assert(_global_dumper == nullptr, "Error");
2722 _global_dumper = this;
2723 }
2724 void set_global_writer() {
2725 assert(_global_writer == nullptr, "Error");
2726 _global_writer = _local_writer;
2727 }
2728 void clear_global_dumper() { _global_dumper = nullptr; }
2729 void clear_global_writer() { _global_writer = nullptr; }
2730
2731 bool skip_operation() const;
2732
2733 // writes a HPROF_LOAD_CLASS record to global writer
2734 static void do_load_class(Klass* k);
2735
2736 // HPROF_GC_ROOT_THREAD_OBJ records for platform and mounted virtual threads
2737 void dump_threads(AbstractDumpWriter* writer);
2738
2739 void add_class_serial_number(Klass* k, int serial_num) {
2740 _klass_map->at_put_grow(serial_num, k);
2741 }
2742
2743 bool is_oom_thread(JavaThread* thread) const {
2744 return thread == _oome_thread && _oome_constructor != nullptr;
2745 }
2746
2747 // HPROF_TRACE and HPROF_FRAME records for platform and mounted virtual threads
2748 void dump_stack_traces(AbstractDumpWriter* writer);
2749
2750 public:
2751 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome, uint num_dump_threads) :
2752 VM_GC_Operation(0 /* total collections, dummy, ignored */,
2753 GCCause::_heap_dump /* GC Cause */,
2754 0 /* total full collections, dummy, ignored */,
2755 gc_before_heap_dump),
2756 WorkerTask("dump heap") {
2757 _local_writer = writer;
2758 _gc_before_heap_dump = gc_before_heap_dump;
2759 _klass_map = new (mtServiceability) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, mtServiceability);
2760
2761 _thread_dumpers = nullptr;
2762 _thread_dumpers_count = 0;
2763 _thread_serial_num = 1;
2764 _frame_serial_num = 1;
2765
2766 _dump_seq = VMDumperId;
2767 _num_dumper_threads = num_dump_threads;
2768 _dumper_controller = nullptr;
2769 _poi = nullptr;
2770 if (oome) {
2771 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
2772 // get OutOfMemoryError zero-parameter constructor
2773 InstanceKlass* oome_ik = vmClasses::OutOfMemoryError_klass();
2774 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
2775 vmSymbols::void_method_signature());
2776 // get thread throwing OOME when generating the heap dump at OOME
2777 _oome_thread = JavaThread::current();
2778 } else {
2779 _oome_thread = nullptr;
2780 _oome_constructor = nullptr;
2781 }
2782 }
2783
2784 ~VM_HeapDumper() {
2785 if (_thread_dumpers != nullptr) {
2786 for (int i = 0; i < _thread_dumpers_count; i++) {
2787 delete _thread_dumpers[i];
2788 }
2789 FREE_C_HEAP_ARRAY(ThreadDumper*, _thread_dumpers);
2790 }
2791
2792 if (_dumper_controller != nullptr) {
2793 delete _dumper_controller;
2794 _dumper_controller = nullptr;
2795 }
2796 delete _klass_map;
2797 }
2798 int dump_seq() { return _dump_seq; }
2799 bool is_parallel_dump() { return _num_dumper_threads > 1; }
2800 void prepare_parallel_dump(WorkerThreads* workers);
2801
2802 InlinedObjects* inlined_objects() { return &_inlined_objects; }
2803
2804 VMOp_Type type() const { return VMOp_HeapDumper; }
2805 virtual bool doit_prologue();
2806 void doit();
2807 void work(uint worker_id);
2808
2809 // UnmountedVThreadDumper implementation
2810 void dump_vthread(oop vt, AbstractDumpWriter* segment_writer);
2811 };
2812
2813 VM_HeapDumper* VM_HeapDumper::_global_dumper = nullptr;
2814 DumpWriter* VM_HeapDumper::_global_writer = nullptr;
2815
2816 bool VM_HeapDumper::skip_operation() const {
2817 return false;
2818 }
2819
2820 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2821 void DumperSupport::end_of_dump(AbstractDumpWriter* writer) {
2822 writer->finish_dump_segment();
2823
2824 writer->write_u1(HPROF_HEAP_DUMP_END);
2825 writer->write_u4(0);
2826 writer->write_u4(0);
2827 }
2828
2829 // writes a HPROF_LOAD_CLASS record for the class
2830 void VM_HeapDumper::do_load_class(Klass* k) {
2831 static u4 class_serial_num = 0;
2832
2833 // len of HPROF_LOAD_CLASS record
2834 u4 remaining = 2*oopSize + 2*sizeof(u4);
2835
2836 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
2837
2838 // class serial number is just a number
2839 writer()->write_u4(++class_serial_num);
2840
2841 // class ID
2842 writer()->write_classID(k);
2843
2844 // add the Klass* and class serial number pair
2845 dumper()->add_class_serial_number(k, class_serial_num);
2846
2847 writer()->write_u4(STACK_TRACE_ID);
2848
2849 // class name ID
2850 Symbol* name = k->name();
2851 writer()->write_symbolID(name);
2852 }
2853
2854 // Write a HPROF_GC_ROOT_THREAD_OBJ record for platform/carrier and mounted virtual threads.
2855 // Then walk the stack so that locals and JNI locals are dumped.
2856 void VM_HeapDumper::dump_threads(AbstractDumpWriter* writer) {
2857 for (int i = 0; i < _thread_dumpers_count; i++) {
2858 _thread_dumpers[i]->dump_thread_obj(writer);
2859 _thread_dumpers[i]->dump_stack_refs(writer);
2860 }
2861 }
2862
2863 bool VM_HeapDumper::doit_prologue() {
2864 if (_gc_before_heap_dump && UseZGC) {
2865 // ZGC cannot perform a synchronous GC cycle from within the VM thread.
2866 // So ZCollectedHeap::collect_as_vm_thread() is a noop. To respect the
2867 // _gc_before_heap_dump flag a synchronous GC cycle is performed from
2868 // the caller thread in the prologue.
2869 Universe::heap()->collect(GCCause::_heap_dump);
2870 }
2871 return VM_GC_Operation::doit_prologue();
2872 }
2873
2874 void VM_HeapDumper::prepare_parallel_dump(WorkerThreads* workers) {
2875 uint num_active_workers = workers != nullptr ? workers->active_workers() : 0;
2876 uint num_requested_dump_threads = _num_dumper_threads;
2877 // check if we can dump in parallel based on requested and active threads
2878 if (num_active_workers <= 1 || num_requested_dump_threads <= 1) {
2879 _num_dumper_threads = 1;
2880 } else {
2881 _num_dumper_threads = clamp(num_requested_dump_threads, 2U, num_active_workers);
2882 }
2883 _dumper_controller = new (std::nothrow) DumperController(_num_dumper_threads);
2884 bool can_parallel = _num_dumper_threads > 1;
2885 log_info(heapdump)("Requested dump threads %u, active dump threads %u, "
2886 "actual dump threads %u, parallelism %s",
2887 num_requested_dump_threads, num_active_workers,
2888 _num_dumper_threads, can_parallel ? "true" : "false");
2889 }
2890
2891 // The VM operation that dumps the heap. The dump consists of the following
2892 // records:
2893 //
2894 // HPROF_HEADER
2895 // [HPROF_UTF8]*
2896 // [HPROF_LOAD_CLASS]*
2897 // [[HPROF_FRAME]*|HPROF_TRACE]*
2898 // [HPROF_GC_CLASS_DUMP]*
2899 // [HPROF_HEAP_DUMP_SEGMENT]*
2900 // HPROF_HEAP_DUMP_END
2901 //
2902 // The HPROF_TRACE records represent the stack traces where the heap dump
2903 // is generated and a "dummy trace" record which does not include
2904 // any frames. The dummy trace record is used to be referenced as the
2905 // unknown object alloc site.
2906 //
2907 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
2908 // To allow the heap dump be generated in a single pass we remember the position
2909 // of the dump length and fix it up after all sub-records have been written.
2910 // To generate the sub-records we iterate over the heap, writing
2911 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
2912 // records as we go. Once that is done we write records for some of the GC
2913 // roots.
2914
2915 void VM_HeapDumper::doit() {
2916
2917 CollectedHeap* ch = Universe::heap();
2918
2919 ch->ensure_parsability(false); // must happen, even if collection does
2920 // not happen (e.g. due to GCLocker)
2921
2922 if (_gc_before_heap_dump) {
2923 if (GCLocker::is_active()) {
2924 warning("GC locker is held; pre-heapdump GC was skipped");
2925 } else {
2926 ch->collect_as_vm_thread(GCCause::_heap_dump);
2927 }
2928 }
2929
2930 // At this point we should be the only dumper active, so
2931 // the following should be safe.
2932 set_global_dumper();
2933 set_global_writer();
2934
2935 WorkerThreads* workers = ch->safepoint_workers();
2936 prepare_parallel_dump(workers);
2937
2938 if (!is_parallel_dump()) {
2939 work(VMDumperId);
2940 } else {
2941 ParallelObjectIterator poi(_num_dumper_threads);
2942 _poi = &poi;
2943 workers->run_task(this, _num_dumper_threads);
2944 _poi = nullptr;
2945 }
2946
2947 // Now we clear the global variables, so that a future dumper can run.
2948 clear_global_dumper();
2949 clear_global_writer();
2950 }
2951
2952 void VM_HeapDumper::work(uint worker_id) {
2953 // VM Dumper works on all non-heap data dumping and part of heap iteration.
2954 int dumper_id = get_next_dumper_id();
2955
2956 if (is_vm_dumper(dumper_id)) {
2957 // lock global writer, it will be unlocked after VM Dumper finishes with non-heap data
2958 _dumper_controller->lock_global_writer();
2959 _dumper_controller->signal_start();
2960 } else {
2961 _dumper_controller->wait_for_start_signal();
2962 }
2963
2964 if (is_vm_dumper(dumper_id)) {
2965 TraceTime timer("Dump non-objects", TRACETIME_LOG(Info, heapdump));
2966 // Write the file header - we always use 1.0.2
2967 const char* header = "JAVA PROFILE 1.0.2";
2968
2969 // header is few bytes long - no chance to overflow int
2970 writer()->write_raw(header, strlen(header) + 1); // NUL terminated
2971 writer()->write_u4(oopSize);
2972 // timestamp is current time in ms
2973 writer()->write_u8(os::javaTimeMillis());
2974 // HPROF_UTF8 records
2975 SymbolTableDumper sym_dumper(writer());
2976 SymbolTable::symbols_do(&sym_dumper);
2977
2978 // HPROF_UTF8 records for inlined field names.
2979 inlined_objects()->init();
2980 inlined_objects()->dump_inlined_field_names(writer());
2981
2982 // HPROF_INLINED_FIELDS
2983 inlined_objects()->dump_classed_with_inlined_fields(writer());
2984
2985 // write HPROF_LOAD_CLASS records
2986 {
2987 LockedClassesDo locked_load_classes(&do_load_class);
2988 ClassLoaderDataGraph::classes_do(&locked_load_classes);
2989 }
2990
2991 // write HPROF_FRAME and HPROF_TRACE records
2992 // this must be called after _klass_map is built when iterating the classes above.
2993 dump_stack_traces(writer());
2994
2995 // unlock global writer, so parallel dumpers can dump stack traces of unmounted virtual threads
2996 _dumper_controller->unlock_global_writer();
2997 }
2998
2999 // HPROF_HEAP_DUMP/HPROF_HEAP_DUMP_SEGMENT starts here
3000
3001 ResourceMark rm;
3002 // share global compressor, local DumpWriter is not responsible for its life cycle
3003 DumpWriter segment_writer(DumpMerger::get_writer_path(writer()->get_file_path(), dumper_id),
3004 writer()->is_overwrite(), writer()->compressor());
3005 if (!segment_writer.has_error()) {
3006 if (is_vm_dumper(dumper_id)) {
3007 // dump some non-heap subrecords to heap dump segment
3008 TraceTime timer("Dump non-objects (part 2)", TRACETIME_LOG(Info, heapdump));
3009 // Writes HPROF_GC_CLASS_DUMP records
3010 ClassDumper class_dumper(&segment_writer);
3011 ClassLoaderDataGraph::classes_do(&class_dumper);
3012
3013 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
3014 dump_threads(&segment_writer);
3015
3016 // HPROF_GC_ROOT_JNI_GLOBAL
3017 JNIGlobalsDumper jni_dumper(&segment_writer);
3018 JNIHandles::oops_do(&jni_dumper);
3019 // technically not jni roots, but global roots
3020 // for things like preallocated throwable backtraces
3021 Universe::vm_global()->oops_do(&jni_dumper);
3022 // HPROF_GC_ROOT_STICKY_CLASS
3023 // These should be classes in the null class loader data, and not all classes
3024 // if !ClassUnloading
3025 StickyClassDumper stiky_class_dumper(&segment_writer);
3026 ClassLoaderData::the_null_class_loader_data()->classes_do(&stiky_class_dumper);
3027 }
3028
3029 // Heap iteration.
3030 // writes HPROF_GC_INSTANCE_DUMP records.
3031 // After each sub-record is written check_segment_length will be invoked
3032 // to check if the current segment exceeds a threshold. If so, a new
3033 // segment is started.
3034 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
3035 // of the heap dump.
3036
3037 TraceTime timer(is_parallel_dump() ? "Dump heap objects in parallel" : "Dump heap objects", TRACETIME_LOG(Info, heapdump));
3038 HeapObjectDumper obj_dumper(&segment_writer, this);
3039 if (!is_parallel_dump()) {
3040 Universe::heap()->object_iterate(&obj_dumper);
3041 } else {
3042 // == Parallel dump
3043 _poi->object_iterate(&obj_dumper, worker_id);
3044 }
3045
3046 segment_writer.finish_dump_segment();
3047 segment_writer.flush();
3048 }
3049
3050 _dumper_controller->dumper_complete(&segment_writer, writer());
3051
3052 if (is_vm_dumper(dumper_id)) {
3053 _dumper_controller->wait_all_dumpers_complete();
3054
3055 // flush global writer
3056 writer()->flush();
3057
3058 // At this point, all fragments of the heapdump have been written to separate files.
3059 // We need to merge them into a complete heapdump and write HPROF_HEAP_DUMP_END at that time.
3060 }
3061 }
3062
3063 void VM_HeapDumper::dump_stack_traces(AbstractDumpWriter* writer) {
3064 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
3065 DumperSupport::write_header(writer, HPROF_TRACE, 3 * sizeof(u4));
3066 writer->write_u4((u4)STACK_TRACE_ID);
3067 writer->write_u4(0); // thread number
3068 writer->write_u4(0); // frame count
3069
3070 // max number if every platform thread is carrier with mounted virtual thread
3071 _thread_dumpers = NEW_C_HEAP_ARRAY(ThreadDumper*, Threads::number_of_threads() * 2, mtInternal);
3072
3073 for (JavaThreadIteratorWithHandle jtiwh; JavaThread * thread = jtiwh.next(); ) {
3074 if (ThreadDumper::should_dump_pthread(thread)) {
3075 bool add_oom_frame = is_oom_thread(thread);
3076
3077 oop mounted_vt = thread->is_vthread_mounted() ? thread->vthread() : nullptr;
3078 if (mounted_vt != nullptr && !ThreadDumper::should_dump_vthread(mounted_vt)) {
3079 mounted_vt = nullptr;
3080 }
3081
3082 // mounted vthread (if any)
3083 if (mounted_vt != nullptr) {
3084 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::MountedVirtual, thread, mounted_vt);
3085 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3086 if (add_oom_frame) {
3087 thread_dumper->add_oom_frame(_oome_constructor);
3088 // we add oom frame to the VT stack, don't add it to the carrier thread stack
3089 add_oom_frame = false;
3090 }
3091 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3092 thread_dumper->dump_stack_traces(writer, _klass_map);
3093 }
3094
3095 // platform or carrier thread
3096 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::Platform, thread, thread->threadObj());
3097 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3098 if (add_oom_frame) {
3099 thread_dumper->add_oom_frame(_oome_constructor);
3100 }
3101 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3102 thread_dumper->dump_stack_traces(writer, _klass_map);
3103 }
3104 }
3105 }
3106
3107 void VM_HeapDumper::dump_vthread(oop vt, AbstractDumpWriter* segment_writer) {
3108 // unmounted vthread has no JavaThread
3109 ThreadDumper thread_dumper(ThreadDumper::ThreadType::UnmountedVirtual, nullptr, vt);
3110 thread_dumper.init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3111
3112 // write HPROF_TRACE/HPROF_FRAME records to global writer
3113 _dumper_controller->lock_global_writer();
3114 thread_dumper.dump_stack_traces(writer(), _klass_map);
3115 _dumper_controller->unlock_global_writer();
3116
3117 // write HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecord
3118 // to segment writer
3119 thread_dumper.dump_thread_obj(segment_writer);
3120 thread_dumper.dump_stack_refs(segment_writer);
3121 }
3122
3123 // dump the heap to given path.
3124 int HeapDumper::dump(const char* path, outputStream* out, int compression, bool overwrite, uint num_dump_threads) {
3125 assert(path != nullptr && strlen(path) > 0, "path missing");
3126
3127 // print message in interactive case
3128 if (out != nullptr) {
3129 out->print_cr("Dumping heap to %s ...", path);
3130 timer()->start();
3131 }
3132
3133 if (_oome && num_dump_threads > 1) {
3134 // Each additional parallel writer requires several MB of internal memory
3135 // (DumpWriter buffer, DumperClassCacheTable, GZipCompressor buffers).
3136 // For the OOM handling we may already be limited in memory.
3137 // Lets ensure we have at least 20MB per thread.
3138 julong max_threads = os::free_memory() / (20 * M);
3139 if (num_dump_threads > max_threads) {
3140 num_dump_threads = MAX2<uint>(1, (uint)max_threads);
3141 }
3142 }
3143
3144 // create JFR event
3145 EventHeapDump event;
3146
3147 AbstractCompressor* compressor = nullptr;
3148
3149 if (compression > 0) {
3150 compressor = new (std::nothrow) GZipCompressor(compression);
3151
3152 if (compressor == nullptr) {
3153 set_error("Could not allocate gzip compressor");
3154 return -1;
3155 }
3156 }
3157
3158 DumpWriter writer(path, overwrite, compressor);
3159
3160 if (writer.error() != nullptr) {
3161 set_error(writer.error());
3162 if (out != nullptr) {
3163 out->print_cr("Unable to create %s: %s", path,
3164 (error() != nullptr) ? error() : "reason unknown");
3165 }
3166 return -1;
3167 }
3168
3169 // generate the segmented heap dump into separate files
3170 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome, num_dump_threads);
3171 VMThread::execute(&dumper);
3172
3173 // record any error that the writer may have encountered
3174 set_error(writer.error());
3175
3176 // Heap dump process is done in two phases
3177 //
3178 // Phase 1: Concurrent threads directly write heap data to multiple heap files.
3179 // This is done by VM_HeapDumper, which is performed within safepoint.
3180 //
3181 // Phase 2: Merge multiple heap files into one complete heap dump file.
3182 // This is done by DumpMerger, which is performed outside safepoint
3183
3184 DumpMerger merger(path, &writer, dumper.inlined_objects(), dumper.dump_seq());
3185 // Perform heapdump file merge operation in the current thread prevents us
3186 // from occupying the VM Thread, which in turn affects the occurrence of
3187 // GC and other VM operations.
3188 merger.do_merge();
3189 if (writer.error() != nullptr) {
3190 set_error(writer.error());
3191 }
3192
3193 // emit JFR event
3194 if (error() == nullptr) {
3195 event.set_destination(path);
3196 event.set_gcBeforeDump(_gc_before_heap_dump);
3197 event.set_size(writer.bytes_written());
3198 event.set_onOutOfMemoryError(_oome);
3199 event.set_overwrite(overwrite);
3200 event.set_compression(compression);
3201 event.commit();
3202 } else {
3203 log_debug(cds, heap)("Error %s while dumping heap", error());
3204 }
3205
3206 // print message in interactive case
3207 if (out != nullptr) {
3208 timer()->stop();
3209 if (error() == nullptr) {
3210 out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
3211 writer.bytes_written(), timer()->seconds());
3212 } else {
3213 out->print_cr("Dump file is incomplete: %s", writer.error());
3214 }
3215 }
3216
3217 if (compressor != nullptr) {
3218 delete compressor;
3219 }
3220 return (writer.error() == nullptr) ? 0 : -1;
3221 }
3222
3223 // stop timer (if still active), and free any error string we might be holding
3224 HeapDumper::~HeapDumper() {
3225 if (timer()->is_active()) {
3226 timer()->stop();
3227 }
3228 set_error(nullptr);
3229 }
3230
3231
3232 // returns the error string (resource allocated), or null
3233 char* HeapDumper::error_as_C_string() const {
3234 if (error() != nullptr) {
3235 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
3236 strcpy(str, error());
3237 return str;
3238 } else {
3239 return nullptr;
3240 }
3241 }
3242
3243 // set the error string
3244 void HeapDumper::set_error(char const* error) {
3245 if (_error != nullptr) {
3246 os::free(_error);
3247 }
3248 if (error == nullptr) {
3249 _error = nullptr;
3250 } else {
3251 _error = os::strdup(error);
3252 assert(_error != nullptr, "allocation failure");
3253 }
3254 }
3255
3256 // Called by out-of-memory error reporting by a single Java thread
3257 // outside of a JVM safepoint
3258 void HeapDumper::dump_heap_from_oome() {
3259 HeapDumper::dump_heap(true);
3260 }
3261
3262 // Called by error reporting by a single Java thread outside of a JVM safepoint,
3263 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
3264 // callers are strictly serialized and guaranteed not to interfere below. For more
3265 // general use, however, this method will need modification to prevent
3266 // inteference when updating the static variables base_path and dump_file_seq below.
3267 void HeapDumper::dump_heap() {
3268 HeapDumper::dump_heap(false);
3269 }
3270
3271 void HeapDumper::dump_heap(bool oome) {
3272 static char base_path[JVM_MAXPATHLEN] = {'\0'};
3273 static uint dump_file_seq = 0;
3274 char* my_path;
3275 const int max_digit_chars = 20;
3276
3277 const char* dump_file_name = "java_pid";
3278 const char* dump_file_ext = HeapDumpGzipLevel > 0 ? ".hprof.gz" : ".hprof";
3279
3280 // The dump file defaults to java_pid<pid>.hprof in the current working
3281 // directory. HeapDumpPath=<file> can be used to specify an alternative
3282 // dump file name or a directory where dump file is created.
3283 if (dump_file_seq == 0) { // first time in, we initialize base_path
3284 // Calculate potentially longest base path and check if we have enough
3285 // allocated statically.
3286 const size_t total_length =
3287 (HeapDumpPath == nullptr ? 0 : strlen(HeapDumpPath)) +
3288 strlen(os::file_separator()) + max_digit_chars +
3289 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
3290 if (total_length > sizeof(base_path)) {
3291 warning("Cannot create heap dump file. HeapDumpPath is too long.");
3292 return;
3293 }
3294
3295 bool use_default_filename = true;
3296 if (HeapDumpPath == nullptr || HeapDumpPath[0] == '\0') {
3297 // HeapDumpPath=<file> not specified
3298 } else {
3299 strcpy(base_path, HeapDumpPath);
3300 // check if the path is a directory (must exist)
3301 DIR* dir = os::opendir(base_path);
3302 if (dir == nullptr) {
3303 use_default_filename = false;
3304 } else {
3305 // HeapDumpPath specified a directory. We append a file separator
3306 // (if needed).
3307 os::closedir(dir);
3308 size_t fs_len = strlen(os::file_separator());
3309 if (strlen(base_path) >= fs_len) {
3310 char* end = base_path;
3311 end += (strlen(base_path) - fs_len);
3312 if (strcmp(end, os::file_separator()) != 0) {
3313 strcat(base_path, os::file_separator());
3314 }
3315 }
3316 }
3317 }
3318 // If HeapDumpPath wasn't a file name then we append the default name
3319 if (use_default_filename) {
3320 const size_t dlen = strlen(base_path); // if heap dump dir specified
3321 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
3322 dump_file_name, os::current_process_id(), dump_file_ext);
3323 }
3324 const size_t len = strlen(base_path) + 1;
3325 my_path = (char*)os::malloc(len, mtInternal);
3326 if (my_path == nullptr) {
3327 warning("Cannot create heap dump file. Out of system memory.");
3328 return;
3329 }
3330 strncpy(my_path, base_path, len);
3331 } else {
3332 // Append a sequence number id for dumps following the first
3333 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
3334 my_path = (char*)os::malloc(len, mtInternal);
3335 if (my_path == nullptr) {
3336 warning("Cannot create heap dump file. Out of system memory.");
3337 return;
3338 }
3339 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
3340 }
3341 dump_file_seq++; // increment seq number for next time we dump
3342
3343 HeapDumper dumper(false /* no GC before heap dump */,
3344 oome /* pass along out-of-memory-error flag */);
3345 dumper.dump(my_path, tty, HeapDumpGzipLevel);
3346 os::free(my_path);
3347 }