1 /*
2 * Copyright (c) 2005, 2025, 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 "classfile/classLoaderData.inline.hpp"
27 #include "classfile/classLoaderDataGraph.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/symbolTable.hpp"
30 #include "classfile/vmClasses.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "gc/shared/gcLocker.hpp"
33 #include "gc/shared/gcVMOperations.hpp"
34 #include "gc/shared/workerThread.hpp"
35 #include "jfr/jfrEvents.hpp"
36 #include "jvm.h"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "memory/universe.hpp"
40 #include "oops/fieldStreams.inline.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "oops/objArrayKlass.hpp"
43 #include "oops/objArrayOop.inline.hpp"
44 #include "oops/flatArrayKlass.hpp"
45 #include "oops/flatArrayOop.inline.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "oops/typeArrayOop.inline.hpp"
48 #include "runtime/continuationWrapper.inline.hpp"
49 #include "runtime/fieldDescriptor.inline.hpp"
50 #include "runtime/frame.inline.hpp"
51 #include "runtime/handles.inline.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/javaThread.inline.hpp"
54 #include "runtime/jniHandles.hpp"
55 #include "runtime/os.hpp"
56 #include "runtime/threads.hpp"
57 #include "runtime/threadSMR.hpp"
58 #include "runtime/vframe.hpp"
59 #include "runtime/vmOperations.hpp"
60 #include "runtime/vmThread.hpp"
61 #include "runtime/timerTrace.hpp"
62 #include "services/heapDumper.hpp"
63 #include "services/heapDumperCompression.hpp"
64 #include "services/threadService.hpp"
65 #include "utilities/checkedCast.hpp"
66 #include "utilities/macros.hpp"
67 #include "utilities/ostream.hpp"
68 #ifdef LINUX
69 #include "os_linux.hpp"
70 #endif
71
72 /*
73 * HPROF binary format - description copied from:
74 * src/share/demo/jvmti/hprof/hprof_io.c
75 *
76 *
77 * header "JAVA PROFILE 1.0.2" (0-terminated)
78 *
79 * u4 size of identifiers. Identifiers are used to represent
80 * UTF8 strings, objects, stack traces, etc. They usually
81 * have the same size as host pointers.
82 * u4 high word
83 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
84 * [record]* a sequence of records.
85 *
86 *
87 * Record format:
88 *
89 * u1 a TAG denoting the type of the record
90 * u4 number of *microseconds* since the time stamp in the
91 * header. (wraps around in a little more than an hour)
92 * u4 number of bytes *remaining* in the record. Note that
93 * this number excludes the tag and the length field itself.
94 * [u1]* BODY of the record (a sequence of bytes)
95 *
96 *
97 * The following TAGs are supported:
98 *
99 * TAG BODY notes
100 *----------------------------------------------------------
101 * HPROF_UTF8 a UTF8-encoded name
102 *
103 * id name ID
104 * [u1]* UTF8 characters (no trailing zero)
105 *
106 * HPROF_LOAD_CLASS a newly loaded class
107 *
108 * u4 class serial number (> 0)
109 * id class object ID
110 * u4 stack trace serial number
111 * id class name ID
112 *
113 * HPROF_UNLOAD_CLASS an unloading class
114 *
115 * u4 class serial_number
116 *
117 * HPROF_FRAME a Java stack frame
118 *
119 * id stack frame ID
120 * id method name ID
121 * id method signature ID
122 * id source file name ID
123 * u4 class serial number
124 * i4 line number. >0: normal
125 * -1: unknown
126 * -2: compiled method
127 * -3: native method
128 *
129 * HPROF_TRACE a Java stack trace
130 *
131 * u4 stack trace serial number
132 * u4 thread serial number
133 * u4 number of frames
134 * [id]* stack frame IDs
135 *
136 *
137 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
138 *
139 * u2 flags 0x0001: incremental vs. complete
140 * 0x0002: sorted by allocation vs. live
141 * 0x0004: whether to force a GC
142 * u4 cutoff ratio
143 * u4 total live bytes
144 * u4 total live instances
145 * u8 total bytes allocated
146 * u8 total instances allocated
147 * u4 number of sites that follow
148 * [u1 is_array: 0: normal object
149 * 2: object array
150 * 4: boolean array
151 * 5: char array
152 * 6: float array
153 * 7: double array
154 * 8: byte array
155 * 9: short array
156 * 10: int array
157 * 11: long array
158 * u4 class serial number (may be zero during startup)
159 * u4 stack trace serial number
160 * u4 number of bytes alive
161 * u4 number of instances alive
162 * u4 number of bytes allocated
163 * u4]* number of instance allocated
164 *
165 * HPROF_START_THREAD a newly started thread.
166 *
167 * u4 thread serial number (> 0)
168 * id thread object ID
169 * u4 stack trace serial number
170 * id thread name ID
171 * id thread group name ID
172 * id thread group parent name ID
173 *
174 * HPROF_END_THREAD a terminating thread.
175 *
176 * u4 thread serial number
177 *
178 * HPROF_HEAP_SUMMARY heap summary
179 *
180 * u4 total live bytes
181 * u4 total live instances
182 * u8 total bytes allocated
183 * u8 total instances allocated
184 *
185 * HPROF_HEAP_DUMP denote a heap dump
186 *
187 * [heap dump sub-records]*
188 *
189 * There are four kinds of heap dump sub-records:
190 *
191 * u1 sub-record type
192 *
193 * HPROF_GC_ROOT_UNKNOWN unknown root
194 *
195 * id object ID
196 *
197 * HPROF_GC_ROOT_THREAD_OBJ thread object
198 *
199 * id thread object ID (may be 0 for a
200 * thread newly attached through JNI)
201 * u4 thread sequence number
202 * u4 stack trace sequence number
203 *
204 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
205 *
206 * id object ID
207 * id JNI global ref ID
208 *
209 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
210 *
211 * id object ID
212 * u4 thread serial number
213 * u4 frame # in stack trace (-1 for empty)
214 *
215 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
216 *
217 * id object ID
218 * u4 thread serial number
219 * u4 frame # in stack trace (-1 for empty)
220 *
221 * HPROF_GC_ROOT_NATIVE_STACK Native stack
222 *
223 * id object ID
224 * u4 thread serial number
225 *
226 * HPROF_GC_ROOT_STICKY_CLASS System class
227 *
228 * id object ID
229 *
230 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
231 *
232 * id object ID
233 * u4 thread serial number
234 *
235 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
236 *
237 * id object ID
238 *
239 * HPROF_GC_CLASS_DUMP dump of a class object
240 *
241 * id class object ID
242 * u4 stack trace serial number
243 * id super class object ID
244 * id class loader object ID
245 * id signers object ID
246 * id protection domain object ID
247 * id reserved
248 * id reserved
249 *
250 * u4 instance size (in bytes)
251 *
252 * u2 size of constant pool
253 * [u2, constant pool index,
254 * ty, type
255 * 2: object
256 * 4: boolean
257 * 5: char
258 * 6: float
259 * 7: double
260 * 8: byte
261 * 9: short
262 * 10: int
263 * 11: long
264 * vl]* and value
265 *
266 * u2 number of static fields
267 * [id, static field name,
268 * ty, type,
269 * vl]* and value
270 *
271 * u2 number of inst. fields (not inc. super)
272 * [id, instance field name,
273 * ty]* type
274 *
275 * HPROF_GC_INSTANCE_DUMP dump of a normal object
276 *
277 * id object ID
278 * u4 stack trace serial number
279 * id class object ID
280 * u4 number of bytes that follow
281 * [vl]* instance field values (class, followed
282 * by super, super's super ...)
283 *
284 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
285 *
286 * id array object ID
287 * u4 stack trace serial number
288 * u4 number of elements
289 * id array class ID
290 * [id]* elements
291 *
292 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
293 *
294 * id array object ID
295 * u4 stack trace serial number
296 * u4 number of elements
297 * u1 element type
298 * 4: boolean array
299 * 5: char array
300 * 6: float array
301 * 7: double array
302 * 8: byte array
303 * 9: short array
304 * 10: int array
305 * 11: long array
306 * [u1]* elements
307 *
308 * HPROF_CPU_SAMPLES a set of sample traces of running threads
309 *
310 * u4 total number of samples
311 * u4 # of traces
312 * [u4 # of samples
313 * u4]* stack trace serial number
314 *
315 * HPROF_CONTROL_SETTINGS the settings of on/off switches
316 *
317 * u4 0x00000001: alloc traces on/off
318 * 0x00000002: cpu sampling on/off
319 * u2 stack trace depth
320 *
321 * HPROF_FLAT_ARRAYS list of flat arrays
322 *
323 * [flat array sub-records]*
324 *
325 * HPROF_FLAT_ARRAY flat array
326 *
327 * id array object ID (dumped as HPROF_GC_PRIM_ARRAY_DUMP)
328 * id element class ID (dumped by HPROF_GC_CLASS_DUMP)
329 *
330 * HPROF_INLINED_FIELDS decribes inlined fields
331 *
332 * [class with inlined fields sub-records]*
333 *
334 * HPROF_CLASS_WITH_INLINED_FIELDS
335 *
336 * id class ID (dumped as HPROF_GC_CLASS_DUMP)
337 *
338 * u2 number of instance inlined fields (not including super)
339 * [u2, inlined field index,
340 * u2, synthetic field count,
341 * id, original field name,
342 * id]* inlined field class ID (dumped by HPROF_GC_CLASS_DUMP)
343 *
344 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
345 * be generated as a sequence of heap dump segments. This sequence is
346 * terminated by an end record. The additional tags allowed by format
347 * "JAVA PROFILE 1.0.2" are:
348 *
349 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
350 *
351 * [heap dump sub-records]*
352 * The same sub-record types allowed by HPROF_HEAP_DUMP
353 *
354 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
355 *
356 */
357
358
359 // HPROF tags
360
361 enum hprofTag : u1 {
362 // top-level records
363 HPROF_UTF8 = 0x01,
364 HPROF_LOAD_CLASS = 0x02,
365 HPROF_UNLOAD_CLASS = 0x03,
366 HPROF_FRAME = 0x04,
367 HPROF_TRACE = 0x05,
368 HPROF_ALLOC_SITES = 0x06,
369 HPROF_HEAP_SUMMARY = 0x07,
370 HPROF_START_THREAD = 0x0A,
371 HPROF_END_THREAD = 0x0B,
372 HPROF_HEAP_DUMP = 0x0C,
373 HPROF_CPU_SAMPLES = 0x0D,
374 HPROF_CONTROL_SETTINGS = 0x0E,
375
376 // 1.0.2 record types
377 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
378 HPROF_HEAP_DUMP_END = 0x2C,
379
380 // inlined object support
381 HPROF_FLAT_ARRAYS = 0x12,
382 HPROF_INLINED_FIELDS = 0x13,
383 // inlined object subrecords
384 HPROF_FLAT_ARRAY = 0x01,
385 HPROF_CLASS_WITH_INLINED_FIELDS = 0x01,
386
387 // field types
388 HPROF_ARRAY_OBJECT = 0x01,
389 HPROF_NORMAL_OBJECT = 0x02,
390 HPROF_BOOLEAN = 0x04,
391 HPROF_CHAR = 0x05,
392 HPROF_FLOAT = 0x06,
393 HPROF_DOUBLE = 0x07,
394 HPROF_BYTE = 0x08,
395 HPROF_SHORT = 0x09,
396 HPROF_INT = 0x0A,
397 HPROF_LONG = 0x0B,
398
399 // data-dump sub-records
400 HPROF_GC_ROOT_UNKNOWN = 0xFF,
401 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
402 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
403 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
404 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
405 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
406 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
407 HPROF_GC_ROOT_MONITOR_USED = 0x07,
408 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
409 HPROF_GC_CLASS_DUMP = 0x20,
410 HPROF_GC_INSTANCE_DUMP = 0x21,
411 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
412 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
413 };
414
415 // Default stack trace ID (used for dummy HPROF_TRACE record)
416 enum {
417 STACK_TRACE_ID = 1,
418 INITIAL_CLASS_COUNT = 200
419 };
420
421
422 class AbstractDumpWriter;
423
424 class InlinedObjects {
425
426 struct ClassInlinedFields {
427 const Klass *klass;
428 uintx base_index; // base index of the inlined field names (1st field has index base_index+1).
429 ClassInlinedFields(const Klass *klass = nullptr, uintx base_index = 0) : klass(klass), base_index(base_index) {}
430
431 // For GrowableArray::find_sorted().
432 static int compare(const ClassInlinedFields& a, const ClassInlinedFields& b) {
433 return a.klass - b.klass;
434 }
435 // For GrowableArray::sort().
436 static int compare(ClassInlinedFields* a, ClassInlinedFields* b) {
437 return compare(*a, *b);
438 }
439 };
440
441 uintx _min_string_id;
442 uintx _max_string_id;
443
444 GrowableArray<ClassInlinedFields> *_inlined_field_map;
445
446 // counters for classes with inlined fields and for the fields
447 int _classes_count;
448 int _inlined_fields_count;
449
450 static InlinedObjects *_instance;
451
452 static void inlined_field_names_callback(InlinedObjects* _this, const Klass *klass, uintx base_index, int count);
453
454 GrowableArray<oop> *_flat_arrays;
455
456 public:
457 InlinedObjects()
458 : _min_string_id(0), _max_string_id(0),
459 _inlined_field_map(nullptr),
460 _classes_count(0), _inlined_fields_count(0),
461 _flat_arrays(nullptr) {
462 }
463
464 static InlinedObjects* get_instance() {
465 return _instance;
466 }
467
468 void init();
469 void release();
470
471 void dump_inlined_field_names(AbstractDumpWriter *writer);
472
473 uintx get_base_index_for(Klass* k);
474 uintx get_next_string_id(uintx id);
475
476 void dump_classed_with_inlined_fields(AbstractDumpWriter* writer);
477
478 void add_flat_array(oop array);
479 void dump_flat_arrays(AbstractDumpWriter* writer);
480
481 };
482
483 InlinedObjects *InlinedObjects::_instance = nullptr;
484
485
486 // Supports I/O operations for a dump
487 // Base class for dump and parallel dump
488 class AbstractDumpWriter : public CHeapObj<mtInternal> {
489 protected:
490 enum {
491 io_buffer_max_size = 1*M,
492 dump_segment_header_size = 9
493 };
494
495 char* _buffer; // internal buffer
496 size_t _size;
497 size_t _pos;
498
499 bool _in_dump_segment; // Are we currently in a dump segment?
500 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
501 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
502 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
503
504 char* buffer() const { return _buffer; }
505 size_t buffer_size() const { return _size; }
506 void set_position(size_t pos) { _pos = pos; }
507
508 // Can be called if we have enough room in the buffer.
509 void write_fast(const void* s, size_t len);
510
511 // Returns true if we have enough room in the buffer for 'len' bytes.
512 bool can_write_fast(size_t len);
513
514 void write_address(address a);
515
516 public:
517 AbstractDumpWriter() :
518 _buffer(nullptr),
519 _size(io_buffer_max_size),
520 _pos(0),
521 _in_dump_segment(false) { }
522
523 // Total number of bytes written to the disk
524 virtual julong bytes_written() const = 0;
525 // Return non-null if error occurred
526 virtual char const* error() const = 0;
527
528 size_t position() const { return _pos; }
529 // writer functions
530 virtual void write_raw(const void* s, size_t len);
531 void write_u1(u1 x);
532 void write_u2(u2 x);
533 void write_u4(u4 x);
534 void write_u8(u8 x);
535 void write_objectID(oop o);
536 void write_rootID(oop* p);
537 void write_symbolID(Symbol* o);
538 void write_classID(Klass* k);
539 void write_id(u4 x);
540
541 // Start a new sub-record. Starts a new heap dump segment if needed.
542 void start_sub_record(u1 tag, u4 len);
543 // Ends the current sub-record.
544 void end_sub_record();
545 // Finishes the current dump segment if not already finished.
546 void finish_dump_segment();
547 // Flush internal buffer to persistent storage
548 virtual void flush() = 0;
549 };
550
551 void AbstractDumpWriter::write_fast(const void* s, size_t len) {
552 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
553 assert(buffer_size() - position() >= len, "Must fit");
554 debug_only(_sub_record_left -= len);
555 memcpy(buffer() + position(), s, len);
556 set_position(position() + len);
557 }
558
559 bool AbstractDumpWriter::can_write_fast(size_t len) {
560 return buffer_size() - position() >= len;
561 }
562
563 // write raw bytes
564 void AbstractDumpWriter::write_raw(const void* s, size_t len) {
565 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
566 debug_only(_sub_record_left -= len);
567
568 // flush buffer to make room.
569 while (len > buffer_size() - position()) {
570 assert(!_in_dump_segment || _is_huge_sub_record,
571 "Cannot overflow in non-huge sub-record.");
572 size_t to_write = buffer_size() - position();
573 memcpy(buffer() + position(), s, to_write);
574 s = (void*) ((char*) s + to_write);
575 len -= to_write;
576 set_position(position() + to_write);
577 flush();
578 }
579
580 memcpy(buffer() + position(), s, len);
581 set_position(position() + len);
582 }
583
584 // Makes sure we inline the fast write into the write_u* functions. This is a big speedup.
585 #define WRITE_KNOWN_TYPE(p, len) do { if (can_write_fast((len))) write_fast((p), (len)); \
586 else write_raw((p), (len)); } while (0)
587
588 void AbstractDumpWriter::write_u1(u1 x) {
589 WRITE_KNOWN_TYPE(&x, 1);
590 }
591
592 void AbstractDumpWriter::write_u2(u2 x) {
593 u2 v;
594 Bytes::put_Java_u2((address)&v, x);
595 WRITE_KNOWN_TYPE(&v, 2);
596 }
597
598 void AbstractDumpWriter::write_u4(u4 x) {
599 u4 v;
600 Bytes::put_Java_u4((address)&v, x);
601 WRITE_KNOWN_TYPE(&v, 4);
602 }
603
604 void AbstractDumpWriter::write_u8(u8 x) {
605 u8 v;
606 Bytes::put_Java_u8((address)&v, x);
607 WRITE_KNOWN_TYPE(&v, 8);
608 }
609
610 void AbstractDumpWriter::write_address(address a) {
611 #ifdef _LP64
612 write_u8((u8)a);
613 #else
614 write_u4((u4)a);
615 #endif
616 }
617
618 void AbstractDumpWriter::write_objectID(oop o) {
619 write_address(cast_from_oop<address>(o));
620 }
621
622 void AbstractDumpWriter::write_rootID(oop* p) {
623 write_address((address)p);
624 }
625
626 void AbstractDumpWriter::write_symbolID(Symbol* s) {
627 write_address((address)((uintptr_t)s));
628 }
629
630 void AbstractDumpWriter::write_id(u4 x) {
631 #ifdef _LP64
632 write_u8((u8) x);
633 #else
634 write_u4(x);
635 #endif
636 }
637
638 // We use java mirror as the class ID
639 void AbstractDumpWriter::write_classID(Klass* k) {
640 write_objectID(k->java_mirror());
641 }
642
643 void AbstractDumpWriter::finish_dump_segment() {
644 if (_in_dump_segment) {
645 assert(_sub_record_left == 0, "Last sub-record not written completely");
646 assert(_sub_record_ended, "sub-record must have ended");
647
648 // Fix up the dump segment length if we haven't written a huge sub-record last
649 // (in which case the segment length was already set to the correct value initially).
650 if (!_is_huge_sub_record) {
651 assert(position() > dump_segment_header_size, "Dump segment should have some content");
652 Bytes::put_Java_u4((address) (buffer() + 5),
653 (u4) (position() - dump_segment_header_size));
654 } else {
655 // Finish process huge sub record
656 // Set _is_huge_sub_record to false so the parallel dump writer can flush data to file.
657 _is_huge_sub_record = false;
658 }
659
660 _in_dump_segment = false;
661 flush();
662 }
663 }
664
665 void AbstractDumpWriter::start_sub_record(u1 tag, u4 len) {
666 if (!_in_dump_segment) {
667 if (position() > 0) {
668 flush();
669 }
670
671 assert(position() == 0 && buffer_size() > dump_segment_header_size, "Must be at the start");
672
673 write_u1(HPROF_HEAP_DUMP_SEGMENT);
674 write_u4(0); // timestamp
675 // Will be fixed up later if we add more sub-records. If this is a huge sub-record,
676 // this is already the correct length, since we don't add more sub-records.
677 write_u4(len);
678 assert(Bytes::get_Java_u4((address)(buffer() + 5)) == len, "Inconsistent size!");
679 _in_dump_segment = true;
680 _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
681 } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
682 // This object will not fit in completely or the last sub-record was huge.
683 // Finish the current segment and try again.
684 finish_dump_segment();
685 start_sub_record(tag, len);
686
687 return;
688 }
689
690 debug_only(_sub_record_left = len);
691 debug_only(_sub_record_ended = false);
692
693 write_u1(tag);
694 }
695
696 void AbstractDumpWriter::end_sub_record() {
697 assert(_in_dump_segment, "must be in dump segment");
698 assert(_sub_record_left == 0, "sub-record not written completely");
699 assert(!_sub_record_ended, "Must not have ended yet");
700 debug_only(_sub_record_ended = true);
701 }
702
703 // Supports I/O operations for a dump
704
705 class DumpWriter : public AbstractDumpWriter {
706 private:
707 FileWriter* _writer;
708 AbstractCompressor* _compressor;
709 size_t _bytes_written;
710 char* _error;
711 // Compression support
712 char* _out_buffer;
713 size_t _out_size;
714 size_t _out_pos;
715 char* _tmp_buffer;
716 size_t _tmp_size;
717
718 private:
719 void do_compress();
720
721 public:
722 DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor);
723 ~DumpWriter();
724 julong bytes_written() const override { return (julong) _bytes_written; }
725 char const* error() const override { return _error; }
726 void set_error(const char* error) { _error = (char*)error; }
727 bool has_error() const { return _error != nullptr; }
728 const char* get_file_path() const { return _writer->get_file_path(); }
729 AbstractCompressor* compressor() { return _compressor; }
730 bool is_overwrite() const { return _writer->is_overwrite(); }
731
732 void flush() override;
733
734 private:
735 // internals for DumpMerger
736 friend class DumpMerger;
737 void set_bytes_written(julong bytes_written) { _bytes_written = bytes_written; }
738 int get_fd() const { return _writer->get_fd(); }
739 void set_compressor(AbstractCompressor* p) { _compressor = p; }
740 };
741
742 DumpWriter::DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor) :
743 AbstractDumpWriter(),
744 _writer(new (std::nothrow) FileWriter(path, overwrite)),
745 _compressor(compressor),
746 _bytes_written(0),
747 _error(nullptr),
748 _out_buffer(nullptr),
749 _out_size(0),
750 _out_pos(0),
751 _tmp_buffer(nullptr),
752 _tmp_size(0) {
753 _error = (char*)_writer->open_writer();
754 if (_error == nullptr) {
755 _buffer = (char*)os::malloc(io_buffer_max_size, mtInternal);
756 if (compressor != nullptr) {
757 _error = (char*)_compressor->init(io_buffer_max_size, &_out_size, &_tmp_size);
758 if (_error == nullptr) {
759 if (_out_size > 0) {
760 _out_buffer = (char*)os::malloc(_out_size, mtInternal);
761 }
762 if (_tmp_size > 0) {
763 _tmp_buffer = (char*)os::malloc(_tmp_size, mtInternal);
764 }
765 }
766 }
767 }
768 // initialize internal buffer
769 _pos = 0;
770 _size = io_buffer_max_size;
771 }
772
773 DumpWriter::~DumpWriter(){
774 if (_buffer != nullptr) {
775 os::free(_buffer);
776 }
777 if (_out_buffer != nullptr) {
778 os::free(_out_buffer);
779 }
780 if (_tmp_buffer != nullptr) {
781 os::free(_tmp_buffer);
782 }
783 if (_writer != nullptr) {
784 delete _writer;
785 }
786 _bytes_written = -1;
787 }
788
789 // flush any buffered bytes to the file
790 void DumpWriter::flush() {
791 if (_pos <= 0) {
792 return;
793 }
794 if (has_error()) {
795 _pos = 0;
796 return;
797 }
798 char* result = nullptr;
799 if (_compressor == nullptr) {
800 result = (char*)_writer->write_buf(_buffer, _pos);
801 _bytes_written += _pos;
802 } else {
803 do_compress();
804 if (!has_error()) {
805 result = (char*)_writer->write_buf(_out_buffer, _out_pos);
806 _bytes_written += _out_pos;
807 }
808 }
809 _pos = 0; // reset pos to make internal buffer available
810
811 if (result != nullptr) {
812 set_error(result);
813 }
814 }
815
816 void DumpWriter::do_compress() {
817 const char* msg = _compressor->compress(_buffer, _pos, _out_buffer, _out_size,
818 _tmp_buffer, _tmp_size, &_out_pos);
819
820 if (msg != nullptr) {
821 set_error(msg);
822 }
823 }
824
825 class DumperClassCacheTable;
826 class DumperClassCacheTableEntry;
827
828 // Support class with a collection of functions used when dumping the heap
829 class DumperSupport : AllStatic {
830 public:
831
832 // write a header of the given type
833 static void write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len);
834
835 // returns hprof tag for the given type signature
836 static hprofTag sig2tag(Symbol* sig);
837 // returns hprof tag for the given basic type
838 static hprofTag type2tag(BasicType type);
839 // Returns the size of the data to write.
840 static u4 sig2size(Symbol* sig);
841
842 // calculates the total size of the all fields of the given class.
843 static u4 instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry = nullptr);
844
845 // dump a jfloat
846 static void dump_float(AbstractDumpWriter* writer, jfloat f);
847 // dump a jdouble
848 static void dump_double(AbstractDumpWriter* writer, jdouble d);
849 // dumps the raw value of the given field
850 static void dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset);
851 // returns the size of the static fields; also counts the static fields
852 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
853 // dumps static fields of the given class
854 static void dump_static_fields(AbstractDumpWriter* writer, Klass* k);
855 // dump the raw values of the instance fields of the given identity or inlined object;
856 // for identity objects offset is 0 and 'klass' is o->klass(),
857 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class
858 static void dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
859 // dump the raw values of the instance fields of the given inlined object;
860 // dump_instance_fields wrapper for inlined objects
861 static void dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
862
863 // get the count of the instance fields for a given class
864 static u2 get_instance_fields_count(InstanceKlass* ik);
865 // dumps the definition of the instance fields for a given class
866 static void dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* k, uintx *inlined_fields_index = nullptr);
867 // creates HPROF_GC_INSTANCE_DUMP record for the given object
868 static void dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache);
869 // creates HPROF_GC_CLASS_DUMP record for the given instance class
870 static void dump_instance_class(AbstractDumpWriter* writer, Klass* k);
871 // creates HPROF_GC_CLASS_DUMP record for a given array class
872 static void dump_array_class(AbstractDumpWriter* writer, Klass* k);
873
874 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
875 static void dump_object_array(AbstractDumpWriter* writer, objArrayOop array);
876 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
877 static void dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache);
878 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
879 static void dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array);
880 // create HPROF_FRAME record for the given method and bci
881 static void dump_stack_frame(AbstractDumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
882
883 // check if we need to truncate an array
884 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size);
885 // extended version to dump flat arrays as primitive arrays;
886 // type_size specifies size of the inlined objects.
887 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size);
888
889 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
890 static void end_of_dump(AbstractDumpWriter* writer);
891
892 static oop mask_dormant_archived_object(oop o, oop ref_obj) {
893 if (o != nullptr && o->klass()->java_mirror_no_keepalive() == nullptr) {
894 // Ignore this object since the corresponding java mirror is not loaded.
895 // Might be a dormant archive object.
896 report_dormant_archived_object(o, ref_obj);
897 return nullptr;
898 } else {
899 return o;
900 }
901 }
902
903 // helper methods for inlined fields.
904 static bool is_inlined_field(const fieldDescriptor& fld) {
905 return fld.is_flat();
906 }
907 static InlineKlass* get_inlined_field_klass(const fieldDescriptor& fld) {
908 assert(is_inlined_field(fld), "must be inlined field");
909 InstanceKlass* holder_klass = fld.field_holder();
910 return InlineKlass::cast(holder_klass->get_inline_type_field_klass(fld.index()));
911 }
912
913 static void report_dormant_archived_object(oop o, oop ref_obj) {
914 if (log_is_enabled(Trace, cds, heap)) {
915 ResourceMark rm;
916 if (ref_obj != nullptr) {
917 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
918 p2i(o), o->klass()->external_name(),
919 p2i(ref_obj), ref_obj->klass()->external_name());
920 } else {
921 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)",
922 p2i(o), o->klass()->external_name());
923 }
924 }
925 }
926 };
927
928 // Hash table of klasses to the klass metadata. This should greatly improve the
929 // hash dumping performance. This hash table is supposed to be used by a single
930 // thread only.
931 //
932 class DumperClassCacheTableEntry : public CHeapObj<mtServiceability> {
933 friend class DumperClassCacheTable;
934 private:
935 GrowableArray<char> _sigs_start;
936 GrowableArray<int> _offsets;
937 GrowableArray<InlineKlass*> _inline_klasses;
938 u4 _instance_size;
939 int _entries;
940
941 public:
942 DumperClassCacheTableEntry() : _instance_size(0), _entries(0) {};
943
944 int field_count() { return _entries; }
945 char sig_start(int field_idx) { return _sigs_start.at(field_idx); }
946 void push_sig_start_inlined() { _sigs_start.push('Q'); }
947 bool is_inlined(int field_idx){ return _sigs_start.at(field_idx) == 'Q'; }
948 InlineKlass* inline_klass(int field_idx) { assert(is_inlined(field_idx), "Not inlined"); return _inline_klasses.at(field_idx); }
949 int offset(int field_idx) { return _offsets.at(field_idx); }
950 u4 instance_size() { return _instance_size; }
951 };
952
953 class DumperClassCacheTable {
954 private:
955 // ResourceHashtable SIZE is specified at compile time so we
956 // use 1031 which is the first prime after 1024.
957 static constexpr size_t TABLE_SIZE = 1031;
958
959 // Maintain the cache for N classes. This limits memory footprint
960 // impact, regardless of how many classes we have in the dump.
961 // This also improves look up performance by keeping the statically
962 // sized table from overloading.
963 static constexpr int CACHE_TOP = 256;
964
965 typedef ResourceHashtable<InstanceKlass*, DumperClassCacheTableEntry*,
966 TABLE_SIZE, AnyObj::C_HEAP, mtServiceability> PtrTable;
967 PtrTable* _ptrs;
968
969 // Single-slot cache to handle the major case of objects of the same
970 // class back-to-back, e.g. from T[].
971 InstanceKlass* _last_ik;
972 DumperClassCacheTableEntry* _last_entry;
973
974 void unlink_all(PtrTable* table) {
975 class CleanupEntry: StackObj {
976 public:
977 bool do_entry(InstanceKlass*& key, DumperClassCacheTableEntry*& entry) {
978 delete entry;
979 return true;
980 }
981 } cleanup;
982 table->unlink(&cleanup);
983 }
984
985 public:
986 DumperClassCacheTableEntry* lookup_or_create(InstanceKlass* ik) {
987 if (_last_ik == ik) {
988 return _last_entry;
989 }
990
991 DumperClassCacheTableEntry* entry;
992 DumperClassCacheTableEntry** from_cache = _ptrs->get(ik);
993 if (from_cache == nullptr) {
994 entry = new DumperClassCacheTableEntry();
995 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
996 if (!fld.access_flags().is_static()) {
997 InlineKlass* inlineKlass = nullptr;
998 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
999 inlineKlass = DumperSupport::get_inlined_field_klass(fld.field_descriptor());
1000 entry->push_sig_start_inlined();
1001 entry->_instance_size += DumperSupport::instance_size(inlineKlass);
1002 } else {
1003 Symbol* sig = fld.signature();
1004 entry->_sigs_start.push(sig->char_at(0));
1005 entry->_instance_size += DumperSupport::sig2size(sig);
1006 }
1007 entry->_inline_klasses.push(inlineKlass);
1008 entry->_offsets.push(fld.offset());
1009 entry->_entries++;
1010 }
1011 }
1012
1013 if (_ptrs->number_of_entries() >= CACHE_TOP) {
1014 // We do not track the individual hit rates for table entries.
1015 // Purge the entire table, and let the cache catch up with new
1016 // distribution.
1017 unlink_all(_ptrs);
1018 }
1019
1020 _ptrs->put(ik, entry);
1021 } else {
1022 entry = *from_cache;
1023 }
1024
1025 // Remember for single-slot cache.
1026 _last_ik = ik;
1027 _last_entry = entry;
1028
1029 return entry;
1030 }
1031
1032 DumperClassCacheTable() : _ptrs(new (mtServiceability) PtrTable), _last_ik(nullptr), _last_entry(nullptr) {}
1033
1034 ~DumperClassCacheTable() {
1035 unlink_all(_ptrs);
1036 delete _ptrs;
1037 }
1038 };
1039
1040 // write a header of the given type
1041 void DumperSupport:: write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len) {
1042 writer->write_u1(tag);
1043 writer->write_u4(0); // current ticks
1044 writer->write_u4(len);
1045 }
1046
1047 // returns hprof tag for the given type signature
1048 hprofTag DumperSupport::sig2tag(Symbol* sig) {
1049 switch (sig->char_at(0)) {
1050 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
1051 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
1052 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
1053 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
1054 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
1055 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
1056 case JVM_SIGNATURE_INT : return HPROF_INT;
1057 case JVM_SIGNATURE_LONG : return HPROF_LONG;
1058 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
1059 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
1060 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1061 }
1062 }
1063
1064 hprofTag DumperSupport::type2tag(BasicType type) {
1065 switch (type) {
1066 case T_BYTE : return HPROF_BYTE;
1067 case T_CHAR : return HPROF_CHAR;
1068 case T_FLOAT : return HPROF_FLOAT;
1069 case T_DOUBLE : return HPROF_DOUBLE;
1070 case T_INT : return HPROF_INT;
1071 case T_LONG : return HPROF_LONG;
1072 case T_SHORT : return HPROF_SHORT;
1073 case T_BOOLEAN : return HPROF_BOOLEAN;
1074 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1075 }
1076 }
1077
1078 u4 DumperSupport::sig2size(Symbol* sig) {
1079 switch (sig->char_at(0)) {
1080 case JVM_SIGNATURE_CLASS:
1081 case JVM_SIGNATURE_ARRAY: return sizeof(address);
1082 case JVM_SIGNATURE_BOOLEAN:
1083 case JVM_SIGNATURE_BYTE: return 1;
1084 case JVM_SIGNATURE_SHORT:
1085 case JVM_SIGNATURE_CHAR: return 2;
1086 case JVM_SIGNATURE_INT:
1087 case JVM_SIGNATURE_FLOAT: return 4;
1088 case JVM_SIGNATURE_LONG:
1089 case JVM_SIGNATURE_DOUBLE: return 8;
1090 default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
1091 }
1092 }
1093
1094 template<typename T, typename F> T bit_cast(F from) { // replace with the real thing when we can use c++20
1095 T to;
1096 static_assert(sizeof(to) == sizeof(from), "must be of the same size");
1097 memcpy(&to, &from, sizeof(to));
1098 return to;
1099 }
1100
1101 // dump a jfloat
1102 void DumperSupport::dump_float(AbstractDumpWriter* writer, jfloat f) {
1103 if (g_isnan(f)) {
1104 writer->write_u4(0x7fc00000); // collapsing NaNs
1105 } else {
1106 writer->write_u4(bit_cast<u4>(f));
1107 }
1108 }
1109
1110 // dump a jdouble
1111 void DumperSupport::dump_double(AbstractDumpWriter* writer, jdouble d) {
1112 if (g_isnan(d)) {
1113 writer->write_u8(0x7ff80000ull << 32); // collapsing NaNs
1114 } else {
1115 writer->write_u8(bit_cast<u8>(d));
1116 }
1117 }
1118
1119
1120 // dumps the raw value of the given field
1121 void DumperSupport::dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset) {
1122 switch (type) {
1123 case JVM_SIGNATURE_CLASS :
1124 case JVM_SIGNATURE_ARRAY : {
1125 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
1126 o = mask_dormant_archived_object(o, obj);
1127 assert(oopDesc::is_oop_or_null(o), "Expected an oop or nullptr at " PTR_FORMAT, p2i(o));
1128 writer->write_objectID(o);
1129 break;
1130 }
1131 case JVM_SIGNATURE_BYTE : {
1132 jbyte b = obj->byte_field(offset);
1133 writer->write_u1(b);
1134 break;
1135 }
1136 case JVM_SIGNATURE_CHAR : {
1137 jchar c = obj->char_field(offset);
1138 writer->write_u2(c);
1139 break;
1140 }
1141 case JVM_SIGNATURE_SHORT : {
1142 jshort s = obj->short_field(offset);
1143 writer->write_u2(s);
1144 break;
1145 }
1146 case JVM_SIGNATURE_FLOAT : {
1147 jfloat f = obj->float_field(offset);
1148 dump_float(writer, f);
1149 break;
1150 }
1151 case JVM_SIGNATURE_DOUBLE : {
1152 jdouble d = obj->double_field(offset);
1153 dump_double(writer, d);
1154 break;
1155 }
1156 case JVM_SIGNATURE_INT : {
1157 jint i = obj->int_field(offset);
1158 writer->write_u4(i);
1159 break;
1160 }
1161 case JVM_SIGNATURE_LONG : {
1162 jlong l = obj->long_field(offset);
1163 writer->write_u8(l);
1164 break;
1165 }
1166 case JVM_SIGNATURE_BOOLEAN : {
1167 jboolean b = obj->bool_field(offset);
1168 writer->write_u1(b);
1169 break;
1170 }
1171 default : {
1172 ShouldNotReachHere();
1173 break;
1174 }
1175 }
1176 }
1177
1178 // calculates the total size of the all fields of the given class.
1179 u4 DumperSupport::instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry) {
1180 if (class_cache_entry != nullptr) {
1181 return class_cache_entry->instance_size();
1182 } else {
1183 u4 size = 0;
1184 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1185 if (!fld.access_flags().is_static()) {
1186 if (is_inlined_field(fld.field_descriptor())) {
1187 size += instance_size(get_inlined_field_klass(fld.field_descriptor()));
1188 } else {
1189 size += sig2size(fld.signature());
1190 }
1191 }
1192 }
1193 return size;
1194 }
1195 }
1196
1197 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1198 field_count = 0;
1199 u4 size = 0;
1200
1201 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1202 if (fldc.access_flags().is_static()) {
1203 assert(!is_inlined_field(fldc.field_descriptor()), "static fields cannot be inlined");
1204
1205 field_count++;
1206 size += sig2size(fldc.signature());
1207 }
1208 }
1209
1210 // Add in resolved_references which is referenced by the cpCache
1211 // The resolved_references is an array per InstanceKlass holding the
1212 // strings and other oops resolved from the constant pool.
1213 oop resolved_references = ik->constants()->resolved_references_or_null();
1214 if (resolved_references != nullptr) {
1215 field_count++;
1216 size += sizeof(address);
1217
1218 // Add in the resolved_references of the used previous versions of the class
1219 // in the case of RedefineClasses
1220 InstanceKlass* prev = ik->previous_versions();
1221 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1222 field_count++;
1223 size += sizeof(address);
1224 prev = prev->previous_versions();
1225 }
1226 }
1227
1228 // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0]
1229 // arrays.
1230 oop init_lock = ik->init_lock();
1231 if (init_lock != nullptr) {
1232 field_count++;
1233 size += sizeof(address);
1234 }
1235
1236 // We write the value itself plus a name and a one byte type tag per field.
1237 return checked_cast<u4>(size + field_count * (sizeof(address) + 1));
1238 }
1239
1240 // dumps static fields of the given class
1241 void DumperSupport::dump_static_fields(AbstractDumpWriter* writer, Klass* k) {
1242 InstanceKlass* ik = InstanceKlass::cast(k);
1243
1244 // dump the field descriptors and raw values
1245 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1246 if (fld.access_flags().is_static()) {
1247 assert(!is_inlined_field(fld.field_descriptor()), "static fields cannot be inlined");
1248
1249 Symbol* sig = fld.signature();
1250
1251 writer->write_symbolID(fld.name()); // name
1252 writer->write_u1(sig2tag(sig)); // type
1253
1254 // value
1255 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1256 }
1257 }
1258
1259 // Add resolved_references for each class that has them
1260 oop resolved_references = ik->constants()->resolved_references_or_null();
1261 if (resolved_references != nullptr) {
1262 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1263 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1264 writer->write_objectID(resolved_references);
1265
1266 // Also write any previous versions
1267 InstanceKlass* prev = ik->previous_versions();
1268 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1269 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1270 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1271 writer->write_objectID(prev->constants()->resolved_references());
1272 prev = prev->previous_versions();
1273 }
1274 }
1275
1276 // Add init lock to the end if the class is not yet initialized
1277 oop init_lock = ik->init_lock();
1278 if (init_lock != nullptr) {
1279 writer->write_symbolID(vmSymbols::init_lock_name()); // name
1280 writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type
1281 writer->write_objectID(init_lock);
1282 }
1283 }
1284
1285 // dump the raw values of the instance fields of the given identity or inlined object;
1286 // for identity objects offset is 0 and 'klass' is o->klass(),
1287 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class.
1288 void DumperSupport::dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1289 assert(class_cache_entry != nullptr, "Pre-condition: must be provided");
1290 for (int idx = 0; idx < class_cache_entry->field_count(); idx++) {
1291 if (class_cache_entry->is_inlined(idx)) {
1292 InlineKlass* field_klass = class_cache_entry->inline_klass(idx);
1293 int fields_offset = offset + (class_cache_entry->offset(idx) - field_klass->payload_offset());
1294 DumperClassCacheTableEntry* inline_class_cache_entry = class_cache->lookup_or_create(field_klass);
1295 dump_inlined_object_fields(writer, o, fields_offset, class_cache, inline_class_cache_entry);
1296 } else {
1297 dump_field_value(writer, class_cache_entry->sig_start(idx), o, class_cache_entry->offset(idx));
1298 }
1299 }
1300 }
1301
1302 void DumperSupport::dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1303 // the object is inlined, so all its fields are stored without headers.
1304 dump_instance_fields(writer, o, offset, class_cache, class_cache_entry);
1305 }
1306
1307 // gets the count of the instance fields for a given class
1308 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1309 u2 field_count = 0;
1310
1311 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1312 if (!fldc.access_flags().is_static()) {
1313 if (is_inlined_field(fldc.field_descriptor())) {
1314 // add "synthetic" fields for inlined fields.
1315 field_count += get_instance_fields_count(get_inlined_field_klass(fldc.field_descriptor()));
1316 } else {
1317 field_count++;
1318 }
1319 }
1320 }
1321
1322 return field_count;
1323 }
1324
1325 // dumps the definition of the instance fields for a given class
1326 // inlined_fields_id is not-nullptr for inlined fields (to get synthetic field name IDs
1327 // by using InlinedObjects::get_next_string_id()).
1328 void DumperSupport::dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* ik, uintx* inlined_fields_id) {
1329 // inlined_fields_id != nullptr means ik is a class of inlined field.
1330 // Inlined field id pointer for this class; lazyly initialized
1331 // if the class has inlined field(s) and the caller didn't provide inlined_fields_id.
1332 uintx *this_klass_inlined_fields_id = inlined_fields_id;
1333 uintx inlined_id = 0;
1334
1335 // dump the field descriptors
1336 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1337 if (!fld.access_flags().is_static()) {
1338 if (is_inlined_field(fld.field_descriptor())) {
1339 // dump "synthetic" fields for inlined fields.
1340 if (this_klass_inlined_fields_id == nullptr) {
1341 inlined_id = InlinedObjects::get_instance()->get_base_index_for(ik);
1342 this_klass_inlined_fields_id = &inlined_id;
1343 }
1344 dump_instance_field_descriptors(writer, get_inlined_field_klass(fld.field_descriptor()), this_klass_inlined_fields_id);
1345 } else {
1346 Symbol* sig = fld.signature();
1347 Symbol* name = nullptr;
1348 // Use inlined_fields_id provided by caller.
1349 if (inlined_fields_id != nullptr) {
1350 uintx name_id = InlinedObjects::get_instance()->get_next_string_id(*inlined_fields_id);
1351
1352 // name_id == 0 is returned on error. use original field signature.
1353 if (name_id != 0) {
1354 *inlined_fields_id = name_id;
1355 name = reinterpret_cast<Symbol*>(name_id);
1356 }
1357 }
1358 if (name == nullptr) {
1359 name = fld.name();
1360 }
1361
1362 writer->write_symbolID(name); // name
1363 writer->write_u1(sig2tag(sig)); // type
1364 }
1365 }
1366 }
1367 }
1368
1369 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1370 void DumperSupport::dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache) {
1371 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1372
1373 DumperClassCacheTableEntry* cache_entry = class_cache->lookup_or_create(ik);
1374
1375 u4 is = instance_size(ik, cache_entry);
1376 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1377
1378 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1379 writer->write_objectID(o);
1380 writer->write_u4(STACK_TRACE_ID);
1381
1382 // class ID
1383 writer->write_classID(ik);
1384
1385 // number of bytes that follow
1386 writer->write_u4(is);
1387
1388 // field values
1389 dump_instance_fields(writer, o, 0, class_cache, cache_entry);
1390
1391 writer->end_sub_record();
1392 }
1393
1394 // creates HPROF_GC_CLASS_DUMP record for the given instance class
1395 void DumperSupport::dump_instance_class(AbstractDumpWriter* writer, Klass* k) {
1396 InstanceKlass* ik = InstanceKlass::cast(k);
1397
1398 // We can safepoint and do a heap dump at a point where we have a Klass,
1399 // but no java mirror class has been setup for it. So we need to check
1400 // that the class is at least loaded, to avoid crash from a null mirror.
1401 if (!ik->is_loaded()) {
1402 return;
1403 }
1404
1405 u2 static_fields_count = 0;
1406 u4 static_size = get_static_fields_size(ik, static_fields_count);
1407 u2 instance_fields_count = get_instance_fields_count(ik);
1408 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1409 u4 size = checked_cast<u4>(1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size);
1410
1411 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1412
1413 // class ID
1414 writer->write_classID(ik);
1415 writer->write_u4(STACK_TRACE_ID);
1416
1417 // super class ID
1418 InstanceKlass* java_super = ik->java_super();
1419 if (java_super == nullptr) {
1420 writer->write_objectID(oop(nullptr));
1421 } else {
1422 writer->write_classID(java_super);
1423 }
1424
1425 writer->write_objectID(ik->class_loader());
1426 writer->write_objectID(ik->signers());
1427 writer->write_objectID(ik->protection_domain());
1428
1429 // reserved
1430 writer->write_objectID(oop(nullptr));
1431 writer->write_objectID(oop(nullptr));
1432
1433 // instance size
1434 writer->write_u4(HeapWordSize * ik->size_helper());
1435
1436 // size of constant pool - ignored by HAT 1.1
1437 writer->write_u2(0);
1438
1439 // static fields
1440 writer->write_u2(static_fields_count);
1441 dump_static_fields(writer, ik);
1442
1443 // description of instance fields
1444 writer->write_u2(instance_fields_count);
1445 dump_instance_field_descriptors(writer, ik);
1446
1447 writer->end_sub_record();
1448 }
1449
1450 // creates HPROF_GC_CLASS_DUMP record for the given array class
1451 void DumperSupport::dump_array_class(AbstractDumpWriter* writer, Klass* k) {
1452 InstanceKlass* ik = nullptr; // bottom class for object arrays, null for primitive type arrays
1453 if (k->is_objArray_klass()) {
1454 Klass *bk = ObjArrayKlass::cast(k)->bottom_klass();
1455 assert(bk != nullptr, "checking");
1456 if (bk->is_instance_klass()) {
1457 ik = InstanceKlass::cast(bk);
1458 }
1459 }
1460
1461 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1462 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1463 writer->write_classID(k);
1464 writer->write_u4(STACK_TRACE_ID);
1465
1466 // super class of array classes is java.lang.Object
1467 InstanceKlass* java_super = k->java_super();
1468 assert(java_super != nullptr, "checking");
1469 writer->write_classID(java_super);
1470
1471 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->class_loader());
1472 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->signers());
1473 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->protection_domain());
1474
1475 writer->write_objectID(oop(nullptr)); // reserved
1476 writer->write_objectID(oop(nullptr));
1477 writer->write_u4(0); // instance size
1478 writer->write_u2(0); // constant pool
1479 writer->write_u2(0); // static fields
1480 writer->write_u2(0); // instance fields
1481
1482 writer->end_sub_record();
1483
1484 }
1485
1486 // Hprof uses an u4 as record length field,
1487 // which means we need to truncate arrays that are too long.
1488 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size) {
1489 int length = array->length();
1490
1491 size_t length_in_bytes = (size_t)length * type_size;
1492 uint max_bytes = max_juint - header_size;
1493
1494 if (length_in_bytes > max_bytes) {
1495 length = max_bytes / type_size;
1496 length_in_bytes = (size_t)length * type_size;
1497
1498 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1499 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1500 type2name_tab[type], array->length(), length);
1501 }
1502 return length;
1503 }
1504
1505 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size) {
1506 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1507 assert((type >= T_BOOLEAN && type <= T_OBJECT) || type == T_FLAT_ELEMENT, "invalid array element type");
1508 int type_size;
1509 if (type == T_OBJECT) {
1510 type_size = sizeof(address);
1511 } else if (type == T_FLAT_ELEMENT) {
1512 // TODO: FIXME
1513 fatal("Not supported yet"); // FIXME: JDK-8325678
1514 } else {
1515 type_size = type2aelembytes(type);
1516 }
1517
1518 return calculate_array_max_length(writer, array, type_size, header_size);
1519 }
1520
1521 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1522 void DumperSupport::dump_object_array(AbstractDumpWriter* writer, objArrayOop array) {
1523 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1524 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1525 int length = calculate_array_max_length(writer, array, header_size);
1526 u4 size = checked_cast<u4>(header_size + length * sizeof(address));
1527
1528 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1529 writer->write_objectID(array);
1530 writer->write_u4(STACK_TRACE_ID);
1531 writer->write_u4(length);
1532
1533 // array class ID
1534 writer->write_classID(array->klass());
1535
1536 // [id]* elements
1537 for (int index = 0; index < length; index++) {
1538 oop o = array->obj_at(index);
1539 o = mask_dormant_archived_object(o, array);
1540 writer->write_objectID(o);
1541 }
1542
1543 writer->end_sub_record();
1544 }
1545
1546 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
1547 void DumperSupport::dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache) {
1548 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1549 InlineKlass* element_klass = array_klass->element_klass();
1550 int element_size = instance_size(element_klass);
1551 /* id array object ID
1552 * u4 stack trace serial number
1553 * u4 number of elements
1554 * u1 element type
1555 */
1556 short header_size = 1 + sizeof(address) + 2 * 4 + 1;
1557
1558 // TODO: use T_SHORT/T_INT/T_LONG if needed to avoid truncation
1559 BasicType type = T_BYTE;
1560 int type_size = type2aelembytes(type);
1561 int length = calculate_array_max_length(writer, array, element_size, header_size);
1562 u4 length_in_bytes = (u4)(length * element_size);
1563 u4 size = header_size + length_in_bytes;
1564
1565 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1566 writer->write_objectID(array);
1567 writer->write_u4(STACK_TRACE_ID);
1568 // TODO: round up array length for T_SHORT/T_INT/T_LONG
1569 writer->write_u4(length * element_size);
1570 writer->write_u1(type2tag(type));
1571
1572 for (int index = 0; index < length; index++) {
1573 // need offset in the holder to read inlined object. calculate it from flatArrayOop::value_at_addr()
1574 int offset = (int)((address)array->value_at_addr(index, array_klass->layout_helper())
1575 - cast_from_oop<address>(array));
1576 DumperClassCacheTableEntry* class_cache_entry = class_cache->lookup_or_create(element_klass);
1577 dump_inlined_object_fields(writer, array, offset, class_cache, class_cache_entry);
1578 }
1579
1580 // TODO: write padding bytes for T_SHORT/T_INT/T_LONG
1581
1582 InlinedObjects::get_instance()->add_flat_array(array);
1583
1584 writer->end_sub_record();
1585 }
1586
1587 #define WRITE_ARRAY(Array, Type, Size, Length) \
1588 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1589
1590 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1591 void DumperSupport::dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array) {
1592 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1593 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1594 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1595
1596 int length = calculate_array_max_length(writer, array, header_size);
1597 int type_size = type2aelembytes(type);
1598 u4 length_in_bytes = (u4)length * type_size;
1599 u4 size = header_size + length_in_bytes;
1600
1601 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1602 writer->write_objectID(array);
1603 writer->write_u4(STACK_TRACE_ID);
1604 writer->write_u4(length);
1605 writer->write_u1(type2tag(type));
1606
1607 // nothing to copy
1608 if (length == 0) {
1609 writer->end_sub_record();
1610 return;
1611 }
1612
1613 // If the byte ordering is big endian then we can copy most types directly
1614
1615 switch (type) {
1616 case T_INT : {
1617 if (Endian::is_Java_byte_ordering_different()) {
1618 WRITE_ARRAY(array, int, u4, length);
1619 } else {
1620 writer->write_raw(array->int_at_addr(0), length_in_bytes);
1621 }
1622 break;
1623 }
1624 case T_BYTE : {
1625 writer->write_raw(array->byte_at_addr(0), length_in_bytes);
1626 break;
1627 }
1628 case T_CHAR : {
1629 if (Endian::is_Java_byte_ordering_different()) {
1630 WRITE_ARRAY(array, char, u2, length);
1631 } else {
1632 writer->write_raw(array->char_at_addr(0), length_in_bytes);
1633 }
1634 break;
1635 }
1636 case T_SHORT : {
1637 if (Endian::is_Java_byte_ordering_different()) {
1638 WRITE_ARRAY(array, short, u2, length);
1639 } else {
1640 writer->write_raw(array->short_at_addr(0), length_in_bytes);
1641 }
1642 break;
1643 }
1644 case T_BOOLEAN : {
1645 if (Endian::is_Java_byte_ordering_different()) {
1646 WRITE_ARRAY(array, bool, u1, length);
1647 } else {
1648 writer->write_raw(array->bool_at_addr(0), length_in_bytes);
1649 }
1650 break;
1651 }
1652 case T_LONG : {
1653 if (Endian::is_Java_byte_ordering_different()) {
1654 WRITE_ARRAY(array, long, u8, length);
1655 } else {
1656 writer->write_raw(array->long_at_addr(0), length_in_bytes);
1657 }
1658 break;
1659 }
1660
1661 // handle float/doubles in a special value to ensure than NaNs are
1662 // written correctly. TO DO: Check if we can avoid this on processors that
1663 // use IEEE 754.
1664
1665 case T_FLOAT : {
1666 for (int i = 0; i < length; i++) {
1667 dump_float(writer, array->float_at(i));
1668 }
1669 break;
1670 }
1671 case T_DOUBLE : {
1672 for (int i = 0; i < length; i++) {
1673 dump_double(writer, array->double_at(i));
1674 }
1675 break;
1676 }
1677 default : ShouldNotReachHere();
1678 }
1679
1680 writer->end_sub_record();
1681 }
1682
1683 // create a HPROF_FRAME record of the given Method* and bci
1684 void DumperSupport::dump_stack_frame(AbstractDumpWriter* writer,
1685 int frame_serial_num,
1686 int class_serial_num,
1687 Method* m,
1688 int bci) {
1689 int line_number;
1690 if (m->is_native()) {
1691 line_number = -3; // native frame
1692 } else {
1693 line_number = m->line_number_from_bci(bci);
1694 }
1695
1696 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1697 writer->write_id(frame_serial_num); // frame serial number
1698 writer->write_symbolID(m->name()); // method's name
1699 writer->write_symbolID(m->signature()); // method's signature
1700
1701 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1702 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1703 writer->write_u4(class_serial_num); // class serial number
1704 writer->write_u4((u4) line_number); // line number
1705 }
1706
1707
1708 class InlinedFieldNameDumper : public LockedClassesDo {
1709 public:
1710 typedef void (*Callback)(InlinedObjects *owner, const Klass *klass, uintx base_index, int count);
1711
1712 private:
1713 AbstractDumpWriter* _writer;
1714 InlinedObjects *_owner;
1715 Callback _callback;
1716 uintx _index;
1717
1718 void dump_inlined_field_names(GrowableArray<Symbol*>* super_names, Symbol* field_name, InlineKlass* klass) {
1719 super_names->push(field_name);
1720 for (HierarchicalFieldStream<JavaFieldStream> fld(klass); !fld.done(); fld.next()) {
1721 if (!fld.access_flags().is_static()) {
1722 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1723 dump_inlined_field_names(super_names, fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1724 } else {
1725 // get next string ID.
1726 uintx next_index = _owner->get_next_string_id(_index);
1727 if (next_index == 0) {
1728 // something went wrong (overflow?)
1729 // stop generation; the rest of inlined objects will have original field names.
1730 return;
1731 }
1732 _index = next_index;
1733
1734 // Calculate length.
1735 int len = fld.name()->utf8_length();
1736 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1737 len += (*it)->utf8_length() + 1; // +1 for ".".
1738 }
1739
1740 DumperSupport::write_header(_writer, HPROF_UTF8, oopSize + len);
1741 _writer->write_symbolID(reinterpret_cast<Symbol*>(_index));
1742 // Write the string value.
1743 // 1) super_names.
1744 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1745 _writer->write_raw((*it)->bytes(), (*it)->utf8_length());
1746 _writer->write_u1('.');
1747 }
1748 // 2) field name.
1749 _writer->write_raw(fld.name()->bytes(), fld.name()->utf8_length());
1750 }
1751 }
1752 }
1753 super_names->pop();
1754 }
1755
1756 void dump_inlined_field_names(Symbol* field_name, InlineKlass* field_klass) {
1757 GrowableArray<Symbol*> super_names(4, mtServiceability);
1758 dump_inlined_field_names(&super_names, field_name, field_klass);
1759 }
1760
1761 public:
1762 InlinedFieldNameDumper(AbstractDumpWriter* writer, InlinedObjects* owner, Callback callback)
1763 : _writer(writer), _owner(owner), _callback(callback), _index(0) {
1764 }
1765
1766 void do_klass(Klass* k) {
1767 if (!k->is_instance_klass()) {
1768 return;
1769 }
1770 InstanceKlass* ik = InstanceKlass::cast(k);
1771 // if (ik->has_inline_type_fields()) {
1772 // return;
1773 // }
1774
1775 uintx base_index = _index;
1776 int count = 0;
1777
1778 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1779 if (!fld.access_flags().is_static()) {
1780 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1781 dump_inlined_field_names(fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1782 count++;
1783 }
1784 }
1785 }
1786
1787 if (count != 0) {
1788 _callback(_owner, k, base_index, count);
1789 }
1790 }
1791 };
1792
1793 class InlinedFieldsDumper : public LockedClassesDo {
1794 private:
1795 AbstractDumpWriter* _writer;
1796
1797 public:
1798 InlinedFieldsDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1799
1800 void do_klass(Klass* k) {
1801 if (!k->is_instance_klass()) {
1802 return;
1803 }
1804 InstanceKlass* ik = InstanceKlass::cast(k);
1805 // if (ik->has_inline_type_fields()) {
1806 // return;
1807 // }
1808
1809 // We can be at a point where java mirror does not exist yet.
1810 // So we need to check that the class is at least loaded, to avoid crash from a null mirror.
1811 if (!ik->is_loaded()) {
1812 return;
1813 }
1814
1815 u2 inlined_count = 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_count++;
1820 }
1821 }
1822 }
1823 if (inlined_count != 0) {
1824 _writer->write_u1(HPROF_CLASS_WITH_INLINED_FIELDS);
1825
1826 // class ID
1827 _writer->write_classID(ik);
1828 // number of inlined fields
1829 _writer->write_u2(inlined_count);
1830 u2 index = 0;
1831 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1832 if (!fld.access_flags().is_static()) {
1833 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1834 // inlined field index
1835 _writer->write_u2(index);
1836 // synthetic field count
1837 u2 field_count = DumperSupport::get_instance_fields_count(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1838 _writer->write_u2(field_count);
1839 // original field name
1840 _writer->write_symbolID(fld.name());
1841 // inlined field class ID
1842 _writer->write_classID(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1843
1844 index += field_count;
1845 } else {
1846 index++;
1847 }
1848 }
1849 }
1850 }
1851 }
1852 };
1853
1854
1855 void InlinedObjects::init() {
1856 _instance = this;
1857
1858 struct Closure : public SymbolClosure {
1859 uintx _min_id = max_uintx;
1860 uintx _max_id = 0;
1861 Closure() : _min_id(max_uintx), _max_id(0) {}
1862
1863 void do_symbol(Symbol** p) {
1864 uintx val = reinterpret_cast<uintx>(*p);
1865 if (val < _min_id) {
1866 _min_id = val;
1867 }
1868 if (val > _max_id) {
1869 _max_id = val;
1870 }
1871 }
1872 } closure;
1873
1874 SymbolTable::symbols_do(&closure);
1875
1876 _min_string_id = closure._min_id;
1877 _max_string_id = closure._max_id;
1878 }
1879
1880 void InlinedObjects::release() {
1881 _instance = nullptr;
1882
1883 if (_inlined_field_map != nullptr) {
1884 delete _inlined_field_map;
1885 _inlined_field_map = nullptr;
1886 }
1887 if (_flat_arrays != nullptr) {
1888 delete _flat_arrays;
1889 _flat_arrays = nullptr;
1890 }
1891 }
1892
1893 void InlinedObjects::inlined_field_names_callback(InlinedObjects* _this, const Klass* klass, uintx base_index, int count) {
1894 if (_this->_inlined_field_map == nullptr) {
1895 _this->_inlined_field_map = new (mtServiceability) GrowableArray<ClassInlinedFields>(100, mtServiceability);
1896 }
1897 _this->_inlined_field_map->append(ClassInlinedFields(klass, base_index));
1898
1899 // counters for dumping classes with inlined fields
1900 _this->_classes_count++;
1901 _this->_inlined_fields_count += count;
1902 }
1903
1904 void InlinedObjects::dump_inlined_field_names(AbstractDumpWriter* writer) {
1905 InlinedFieldNameDumper nameDumper(writer, this, inlined_field_names_callback);
1906 ClassLoaderDataGraph::classes_do(&nameDumper);
1907
1908 if (_inlined_field_map != nullptr) {
1909 // prepare the map for get_base_index_for().
1910 _inlined_field_map->sort(ClassInlinedFields::compare);
1911 }
1912 }
1913
1914 uintx InlinedObjects::get_base_index_for(Klass* k) {
1915 if (_inlined_field_map != nullptr) {
1916 bool found = false;
1917 int idx = _inlined_field_map->find_sorted<ClassInlinedFields, ClassInlinedFields::compare>(ClassInlinedFields(k, 0), found);
1918 if (found) {
1919 return _inlined_field_map->at(idx).base_index;
1920 }
1921 }
1922
1923 // return max_uintx, so get_next_string_id returns 0.
1924 return max_uintx;
1925 }
1926
1927 uintx InlinedObjects::get_next_string_id(uintx id) {
1928 if (++id == _min_string_id) {
1929 return _max_string_id + 1;
1930 }
1931 return id;
1932 }
1933
1934 void InlinedObjects::dump_classed_with_inlined_fields(AbstractDumpWriter* writer) {
1935 if (_classes_count != 0) {
1936 // Record for each class contains tag(u1), class ID and count(u2)
1937 // for each inlined field index(u2), synthetic fields count(u2), original field name and class ID
1938 int size = _classes_count * (1 + sizeof(address) + 2)
1939 + _inlined_fields_count * (2 + 2 + sizeof(address) + sizeof(address));
1940 DumperSupport::write_header(writer, HPROF_INLINED_FIELDS, (u4)size);
1941
1942 InlinedFieldsDumper dumper(writer);
1943 ClassLoaderDataGraph::classes_do(&dumper);
1944 }
1945 }
1946
1947 void InlinedObjects::add_flat_array(oop array) {
1948 if (_flat_arrays == nullptr) {
1949 _flat_arrays = new (mtServiceability) GrowableArray<oop>(100, mtServiceability);
1950 }
1951 _flat_arrays->append(array);
1952 }
1953
1954 void InlinedObjects::dump_flat_arrays(AbstractDumpWriter* writer) {
1955 if (_flat_arrays != nullptr) {
1956 // For each flat array the record contains tag (u1), object ID and class ID.
1957 int size = _flat_arrays->length() * (1 + sizeof(address) + sizeof(address));
1958
1959 DumperSupport::write_header(writer, HPROF_FLAT_ARRAYS, (u4)size);
1960 for (GrowableArrayIterator<oop> it = _flat_arrays->begin(); it != _flat_arrays->end(); ++it) {
1961 flatArrayOop array = flatArrayOop(*it);
1962 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1963 InlineKlass* element_klass = array_klass->element_klass();
1964 writer->write_u1(HPROF_FLAT_ARRAY);
1965 writer->write_objectID(array);
1966 writer->write_classID(element_klass);
1967 }
1968 }
1969 }
1970
1971
1972 // Support class used to generate HPROF_UTF8 records from the entries in the
1973 // SymbolTable.
1974
1975 class SymbolTableDumper : public SymbolClosure {
1976 private:
1977 AbstractDumpWriter* _writer;
1978 AbstractDumpWriter* writer() const { return _writer; }
1979 public:
1980 SymbolTableDumper(AbstractDumpWriter* writer) { _writer = writer; }
1981 void do_symbol(Symbol** p);
1982 };
1983
1984 void SymbolTableDumper::do_symbol(Symbol** p) {
1985 ResourceMark rm;
1986 Symbol* sym = *p;
1987 int len = sym->utf8_length();
1988 if (len > 0) {
1989 char* s = sym->as_utf8();
1990 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1991 writer()->write_symbolID(sym);
1992 writer()->write_raw(s, len);
1993 }
1994 }
1995
1996 // Support class used to generate HPROF_GC_CLASS_DUMP records
1997
1998 class ClassDumper : public KlassClosure {
1999 private:
2000 AbstractDumpWriter* _writer;
2001 AbstractDumpWriter* writer() const { return _writer; }
2002
2003 public:
2004 ClassDumper(AbstractDumpWriter* writer) : _writer(writer) {}
2005
2006 void do_klass(Klass* k) {
2007 if (k->is_instance_klass()) {
2008 DumperSupport::dump_instance_class(writer(), k);
2009 } else {
2010 DumperSupport::dump_array_class(writer(), k);
2011 }
2012 }
2013 };
2014
2015 // Support class used to generate HPROF_LOAD_CLASS records
2016
2017 class LoadedClassDumper : public LockedClassesDo {
2018 private:
2019 AbstractDumpWriter* _writer;
2020 GrowableArray<Klass*>* _klass_map;
2021 u4 _class_serial_num;
2022 AbstractDumpWriter* writer() const { return _writer; }
2023 void add_class_serial_number(Klass* k, int serial_num) {
2024 _klass_map->at_put_grow(serial_num, k);
2025 }
2026 public:
2027 LoadedClassDumper(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map)
2028 : _writer(writer), _klass_map(klass_map), _class_serial_num(0) {}
2029
2030 void do_klass(Klass* k) {
2031 // len of HPROF_LOAD_CLASS record
2032 u4 remaining = 2 * oopSize + 2 * sizeof(u4);
2033 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
2034 // class serial number is just a number
2035 writer()->write_u4(++_class_serial_num);
2036 // class ID
2037 writer()->write_classID(k);
2038 // add the Klass* and class serial number pair
2039 add_class_serial_number(k, _class_serial_num);
2040 writer()->write_u4(STACK_TRACE_ID);
2041 // class name ID
2042 Symbol* name = k->name();
2043 writer()->write_symbolID(name);
2044 }
2045 };
2046
2047 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
2048
2049 class JNILocalsDumper : public OopClosure {
2050 private:
2051 AbstractDumpWriter* _writer;
2052 u4 _thread_serial_num;
2053 int _frame_num;
2054 AbstractDumpWriter* writer() const { return _writer; }
2055 public:
2056 JNILocalsDumper(AbstractDumpWriter* writer, u4 thread_serial_num) {
2057 _writer = writer;
2058 _thread_serial_num = thread_serial_num;
2059 _frame_num = -1; // default - empty stack
2060 }
2061 void set_frame_number(int n) { _frame_num = n; }
2062 void do_oop(oop* obj_p);
2063 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2064 };
2065
2066 void JNILocalsDumper::do_oop(oop* obj_p) {
2067 // ignore null handles
2068 oop o = *obj_p;
2069 if (o != nullptr) {
2070 u4 size = 1 + sizeof(address) + 4 + 4;
2071 writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
2072 writer()->write_objectID(o);
2073 writer()->write_u4(_thread_serial_num);
2074 writer()->write_u4((u4)_frame_num);
2075 writer()->end_sub_record();
2076 }
2077 }
2078
2079
2080 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
2081
2082 class JNIGlobalsDumper : public OopClosure {
2083 private:
2084 AbstractDumpWriter* _writer;
2085 AbstractDumpWriter* writer() const { return _writer; }
2086
2087 public:
2088 JNIGlobalsDumper(AbstractDumpWriter* writer) {
2089 _writer = writer;
2090 }
2091 void do_oop(oop* obj_p);
2092 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2093 };
2094
2095 void JNIGlobalsDumper::do_oop(oop* obj_p) {
2096 oop o = NativeAccess<AS_NO_KEEPALIVE>::oop_load(obj_p);
2097
2098 // ignore these
2099 if (o == nullptr) return;
2100 // we ignore global ref to symbols and other internal objects
2101 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
2102 u4 size = 1 + 2 * sizeof(address);
2103 writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
2104 writer()->write_objectID(o);
2105 writer()->write_rootID(obj_p); // global ref ID
2106 writer()->end_sub_record();
2107 }
2108 };
2109
2110 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
2111
2112 class StickyClassDumper : public KlassClosure {
2113 private:
2114 AbstractDumpWriter* _writer;
2115 AbstractDumpWriter* writer() const { return _writer; }
2116 public:
2117 StickyClassDumper(AbstractDumpWriter* writer) {
2118 _writer = writer;
2119 }
2120 void do_klass(Klass* k) {
2121 if (k->is_instance_klass()) {
2122 InstanceKlass* ik = InstanceKlass::cast(k);
2123 u4 size = 1 + sizeof(address);
2124 writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
2125 writer()->write_classID(ik);
2126 writer()->end_sub_record();
2127 }
2128 }
2129 };
2130
2131 // Support class used to generate HPROF_GC_ROOT_JAVA_FRAME records.
2132
2133 class JavaStackRefDumper : public StackObj {
2134 private:
2135 AbstractDumpWriter* _writer;
2136 u4 _thread_serial_num;
2137 int _frame_num;
2138 AbstractDumpWriter* writer() const { return _writer; }
2139 public:
2140 JavaStackRefDumper(AbstractDumpWriter* writer, u4 thread_serial_num)
2141 : _writer(writer), _thread_serial_num(thread_serial_num), _frame_num(-1) // default - empty stack
2142 {
2143 }
2144
2145 void set_frame_number(int n) { _frame_num = n; }
2146
2147 void dump_java_stack_refs(StackValueCollection* values);
2148 };
2149
2150 void JavaStackRefDumper::dump_java_stack_refs(StackValueCollection* values) {
2151 for (int index = 0; index < values->size(); index++) {
2152 if (values->at(index)->type() == T_OBJECT) {
2153 oop o = values->obj_at(index)();
2154 if (o != nullptr) {
2155 u4 size = 1 + sizeof(address) + 4 + 4;
2156 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
2157 writer()->write_objectID(o);
2158 writer()->write_u4(_thread_serial_num);
2159 writer()->write_u4((u4)_frame_num);
2160 writer()->end_sub_record();
2161 }
2162 }
2163 }
2164 }
2165
2166 // Class to collect, store and dump thread-related data:
2167 // - HPROF_TRACE and HPROF_FRAME records;
2168 // - HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecords.
2169 class ThreadDumper : public CHeapObj<mtInternal> {
2170 public:
2171 enum class ThreadType { Platform, MountedVirtual, UnmountedVirtual };
2172
2173 private:
2174 ThreadType _thread_type;
2175 JavaThread* _java_thread;
2176 oop _thread_oop;
2177
2178 GrowableArray<StackFrameInfo*>* _frames;
2179 // non-null if the thread is OOM thread
2180 Method* _oome_constructor;
2181 int _thread_serial_num;
2182 int _start_frame_serial_num;
2183
2184 vframe* get_top_frame() const;
2185
2186 public:
2187 static bool should_dump_pthread(JavaThread* thread) {
2188 return thread->threadObj() != nullptr && !thread->is_exiting() && !thread->is_hidden_from_external_view();
2189 }
2190
2191 static bool should_dump_vthread(oop vt) {
2192 return java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::NEW
2193 && java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::TERMINATED;
2194 }
2195
2196 static bool is_vthread_mounted(oop vt) {
2197 // The code should be consistent with the "mounted virtual thread" case
2198 // (VM_HeapDumper::dump_stack_traces(), ThreadDumper::get_top_frame()).
2199 // I.e. virtual thread is mounted if its carrierThread is not null
2200 // and is_vthread_mounted() for the carrier thread returns true.
2201 oop carrier_thread = java_lang_VirtualThread::carrier_thread(vt);
2202 if (carrier_thread == nullptr) {
2203 return false;
2204 }
2205 JavaThread* java_thread = java_lang_Thread::thread(carrier_thread);
2206 return java_thread->is_vthread_mounted();
2207 }
2208
2209 ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop);
2210 ~ThreadDumper() {
2211 for (int index = 0; index < _frames->length(); index++) {
2212 delete _frames->at(index);
2213 }
2214 delete _frames;
2215 }
2216
2217 // affects frame_count
2218 void add_oom_frame(Method* oome_constructor) {
2219 assert(_start_frame_serial_num == 0, "add_oom_frame cannot be called after init_serial_nums");
2220 _oome_constructor = oome_constructor;
2221 }
2222
2223 void init_serial_nums(volatile int* thread_counter, volatile int* frame_counter) {
2224 assert(_start_frame_serial_num == 0, "already initialized");
2225 _thread_serial_num = Atomic::fetch_then_add(thread_counter, 1);
2226 _start_frame_serial_num = Atomic::fetch_then_add(frame_counter, frame_count());
2227 }
2228
2229 bool oom_thread() const {
2230 return _oome_constructor != nullptr;
2231 }
2232
2233 int frame_count() const {
2234 return _frames->length() + (oom_thread() ? 1 : 0);
2235 }
2236
2237 u4 thread_serial_num() const {
2238 return (u4)_thread_serial_num;
2239 }
2240
2241 u4 stack_trace_serial_num() const {
2242 return (u4)(_thread_serial_num + STACK_TRACE_ID);
2243 }
2244
2245 // writes HPROF_TRACE and HPROF_FRAME records
2246 // returns number of dumped frames
2247 void dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map);
2248
2249 // writes HPROF_GC_ROOT_THREAD_OBJ subrecord
2250 void dump_thread_obj(AbstractDumpWriter* writer);
2251
2252 // Walk the stack of the thread.
2253 // Dumps a HPROF_GC_ROOT_JAVA_FRAME subrecord for each local
2254 // Dumps a HPROF_GC_ROOT_JNI_LOCAL subrecord for each JNI local
2255 void dump_stack_refs(AbstractDumpWriter* writer);
2256
2257 };
2258
2259 ThreadDumper::ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop)
2260 : _thread_type(thread_type), _java_thread(java_thread), _thread_oop(thread_oop),
2261 _oome_constructor(nullptr),
2262 _thread_serial_num(0), _start_frame_serial_num(0)
2263 {
2264 // sanity checks
2265 if (_thread_type == ThreadType::UnmountedVirtual) {
2266 assert(_java_thread == nullptr, "sanity");
2267 assert(_thread_oop != nullptr, "sanity");
2268 } else {
2269 assert(_java_thread != nullptr, "sanity");
2270 assert(_thread_oop != nullptr, "sanity");
2271 }
2272
2273 _frames = new (mtServiceability) GrowableArray<StackFrameInfo*>(10, mtServiceability);
2274 bool stop_at_vthread_entry = _thread_type == ThreadType::MountedVirtual;
2275
2276 // vframes are resource allocated
2277 Thread* current_thread = Thread::current();
2278 ResourceMark rm(current_thread);
2279 HandleMark hm(current_thread);
2280
2281 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2282 if (stop_at_vthread_entry && vf->is_vthread_entry()) {
2283 break;
2284 }
2285 if (vf->is_java_frame()) {
2286 javaVFrame* jvf = javaVFrame::cast(vf);
2287 _frames->append(new StackFrameInfo(jvf, false));
2288 } else {
2289 // ignore non-Java frames
2290 }
2291 }
2292 }
2293
2294 void ThreadDumper::dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map) {
2295 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_nums are not initialized");
2296
2297 // write HPROF_FRAME records for this thread's stack trace
2298 int depth = _frames->length();
2299 int frame_serial_num = _start_frame_serial_num;
2300
2301 if (oom_thread()) {
2302 // OOM thread
2303 // write fake frame that makes it look like the thread, which caused OOME,
2304 // is in the OutOfMemoryError zero-parameter constructor
2305 int oome_serial_num = klass_map->find(_oome_constructor->method_holder());
2306 // the class serial number starts from 1
2307 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
2308 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, oome_serial_num, _oome_constructor, 0);
2309 depth++;
2310 }
2311
2312 for (int j = 0; j < _frames->length(); j++) {
2313 StackFrameInfo* frame = _frames->at(j);
2314 Method* m = frame->method();
2315 int class_serial_num = klass_map->find(m->method_holder());
2316 // the class serial number starts from 1
2317 assert(class_serial_num > 0, "class not found");
2318 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, class_serial_num, m, frame->bci());
2319 }
2320
2321 // write HPROF_TRACE record for the thread
2322 DumperSupport::write_header(writer, HPROF_TRACE, checked_cast<u4>(3 * sizeof(u4) + depth * oopSize));
2323 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2324 writer->write_u4(thread_serial_num()); // thread serial number
2325 writer->write_u4((u4)depth); // frame count (including oom frame)
2326 for (int j = 1; j <= depth; j++) {
2327 writer->write_id(_start_frame_serial_num + j);
2328 }
2329 }
2330
2331 void ThreadDumper::dump_thread_obj(AbstractDumpWriter * writer) {
2332 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2333
2334 u4 size = 1 + sizeof(address) + 4 + 4;
2335 writer->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
2336 writer->write_objectID(_thread_oop);
2337 writer->write_u4(thread_serial_num()); // thread serial number
2338 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2339 writer->end_sub_record();
2340 }
2341
2342 void ThreadDumper::dump_stack_refs(AbstractDumpWriter * writer) {
2343 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2344
2345 JNILocalsDumper blk(writer, thread_serial_num());
2346 if (_thread_type == ThreadType::Platform) {
2347 if (!_java_thread->has_last_Java_frame()) {
2348 // no last java frame but there may be JNI locals
2349 _java_thread->active_handles()->oops_do(&blk);
2350 return;
2351 }
2352 }
2353
2354 JavaStackRefDumper java_ref_dumper(writer, thread_serial_num());
2355
2356 // vframes are resource allocated
2357 Thread* current_thread = Thread::current();
2358 ResourceMark rm(current_thread);
2359 HandleMark hm(current_thread);
2360
2361 bool stopAtVthreadEntry = _thread_type == ThreadType::MountedVirtual;
2362 frame* last_entry_frame = nullptr;
2363 bool is_top_frame = true;
2364 int depth = 0;
2365 if (oom_thread()) {
2366 depth++;
2367 }
2368
2369 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2370 if (stopAtVthreadEntry && vf->is_vthread_entry()) {
2371 break;
2372 }
2373
2374 if (vf->is_java_frame()) {
2375 javaVFrame* jvf = javaVFrame::cast(vf);
2376 if (!(jvf->method()->is_native())) {
2377 java_ref_dumper.set_frame_number(depth);
2378 java_ref_dumper.dump_java_stack_refs(jvf->locals());
2379 java_ref_dumper.dump_java_stack_refs(jvf->expressions());
2380 } else {
2381 // native frame
2382 blk.set_frame_number(depth);
2383 if (is_top_frame) {
2384 // JNI locals for the top frame if mounted
2385 assert(_java_thread != nullptr || jvf->method()->is_synchronized()
2386 || jvf->method()->is_object_wait0(), "impossible for unmounted vthread");
2387 if (_java_thread != nullptr) {
2388 _java_thread->active_handles()->oops_do(&blk);
2389 }
2390 } else {
2391 if (last_entry_frame != nullptr) {
2392 // JNI locals for the entry frame
2393 assert(last_entry_frame->is_entry_frame(), "checking");
2394 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
2395 }
2396 }
2397 }
2398 last_entry_frame = nullptr;
2399 // increment only for Java frames
2400 depth++;
2401 } else {
2402 // externalVFrame - for an entry frame then we report the JNI locals
2403 // when we find the corresponding javaVFrame
2404 frame* fr = vf->frame_pointer();
2405 assert(fr != nullptr, "sanity check");
2406 if (fr->is_entry_frame()) {
2407 last_entry_frame = fr;
2408 }
2409 }
2410 is_top_frame = false;
2411 }
2412 assert(depth == frame_count(), "total number of Java frames not matched");
2413 }
2414
2415 vframe* ThreadDumper::get_top_frame() const {
2416 if (_thread_type == ThreadType::UnmountedVirtual) {
2417 ContinuationWrapper cont(java_lang_VirtualThread::continuation(_thread_oop));
2418 if (cont.is_empty()) {
2419 return nullptr;
2420 }
2421 assert(!cont.is_mounted(), "sanity check");
2422 stackChunkOop chunk = cont.last_nonempty_chunk();
2423 if (chunk == nullptr || chunk->is_empty()) {
2424 return nullptr;
2425 }
2426
2427 RegisterMap reg_map(cont.continuation(), RegisterMap::UpdateMap::include);
2428 frame fr = chunk->top_frame(®_map);
2429 vframe* vf = vframe::new_vframe(&fr, ®_map, nullptr); // don't need JavaThread
2430 return vf;
2431 }
2432
2433 RegisterMap reg_map(_java_thread,
2434 RegisterMap::UpdateMap::include,
2435 RegisterMap::ProcessFrames::include,
2436 RegisterMap::WalkContinuation::skip);
2437 switch (_thread_type) {
2438 case ThreadType::Platform:
2439 if (!_java_thread->has_last_Java_frame()) {
2440 return nullptr;
2441 }
2442 return _java_thread->is_vthread_mounted()
2443 ? _java_thread->carrier_last_java_vframe(®_map)
2444 : _java_thread->platform_thread_last_java_vframe(®_map);
2445
2446 case ThreadType::MountedVirtual:
2447 return _java_thread->last_java_vframe(®_map);
2448
2449 default: // make compilers happy
2450 break;
2451 }
2452 ShouldNotReachHere();
2453 return nullptr;
2454 }
2455
2456 // Callback to dump thread-related data for unmounted virtual threads;
2457 // implemented by VM_HeapDumper.
2458 class UnmountedVThreadDumper {
2459 public:
2460 virtual void dump_vthread(oop vt, AbstractDumpWriter* segment_writer) = 0;
2461 };
2462
2463 // Support class used when iterating over the heap.
2464 class HeapObjectDumper : public ObjectClosure {
2465 private:
2466 AbstractDumpWriter* _writer;
2467 AbstractDumpWriter* writer() { return _writer; }
2468 UnmountedVThreadDumper* _vthread_dumper;
2469
2470 DumperClassCacheTable _class_cache;
2471
2472 public:
2473 HeapObjectDumper(AbstractDumpWriter* writer, UnmountedVThreadDumper* vthread_dumper)
2474 : _writer(writer), _vthread_dumper(vthread_dumper) {}
2475
2476 // called for each object in the heap
2477 void do_object(oop o);
2478 };
2479
2480 void HeapObjectDumper::do_object(oop o) {
2481 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
2482 if (o->klass() == vmClasses::Class_klass()) {
2483 if (!java_lang_Class::is_primitive(o)) {
2484 return;
2485 }
2486 }
2487
2488 if (DumperSupport::mask_dormant_archived_object(o, nullptr) == nullptr) {
2489 return;
2490 }
2491
2492 if (o->is_instance()) {
2493 // create a HPROF_GC_INSTANCE record for each object
2494 DumperSupport::dump_instance(writer(), o, &_class_cache);
2495 // If we encounter an unmounted virtual thread it needs to be dumped explicitly
2496 // (mounted virtual threads are dumped with their carriers).
2497 if (java_lang_VirtualThread::is_instance(o)
2498 && ThreadDumper::should_dump_vthread(o) && !ThreadDumper::is_vthread_mounted(o)) {
2499 _vthread_dumper->dump_vthread(o, writer());
2500 }
2501 } else if (o->is_objArray()) {
2502 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
2503 DumperSupport::dump_object_array(writer(), objArrayOop(o));
2504 } else if (o->is_flatArray()) {
2505 DumperSupport::dump_flat_array(writer(), flatArrayOop(o), &_class_cache);
2506 } else if (o->is_typeArray()) {
2507 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
2508 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
2509 }
2510 }
2511
2512 // The dumper controller for parallel heap dump
2513 class DumperController : public CHeapObj<mtInternal> {
2514 private:
2515 Monitor* _lock;
2516 Mutex* _global_writer_lock;
2517
2518 const uint _dumper_number;
2519 uint _complete_number;
2520
2521 bool _started; // VM dumper started and acquired global writer lock
2522
2523 public:
2524 DumperController(uint number) :
2525 // _lock and _global_writer_lock are used for synchronization between GC worker threads inside safepoint,
2526 // so we lock with _no_safepoint_check_flag.
2527 // signal_start() acquires _lock when global writer is locked,
2528 // its rank must be less than _global_writer_lock rank.
2529 _lock(new (std::nothrow) PaddedMonitor(Mutex::nosafepoint - 1, "DumperController_lock")),
2530 _global_writer_lock(new (std::nothrow) Mutex(Mutex::nosafepoint, "DumpWriter_lock")),
2531 _dumper_number(number),
2532 _complete_number(0),
2533 _started(false)
2534 {}
2535
2536 ~DumperController() {
2537 delete _lock;
2538 delete _global_writer_lock;
2539 }
2540
2541 // parallel (non VM) dumpers must wait until VM dumper acquires global writer lock
2542 void wait_for_start_signal() {
2543 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2544 while (_started == false) {
2545 ml.wait();
2546 }
2547 }
2548
2549 void signal_start() {
2550 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2551 _started = true;
2552 ml.notify_all();
2553 }
2554
2555 void lock_global_writer() {
2556 _global_writer_lock->lock_without_safepoint_check();
2557 }
2558
2559 void unlock_global_writer() {
2560 _global_writer_lock->unlock();
2561 }
2562
2563 void dumper_complete(DumpWriter* local_writer, DumpWriter* global_writer) {
2564 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2565 _complete_number++;
2566 // propagate local error to global if any
2567 if (local_writer->has_error()) {
2568 global_writer->set_error(local_writer->error());
2569 }
2570 ml.notify();
2571 }
2572
2573 void wait_all_dumpers_complete() {
2574 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2575 while (_complete_number != _dumper_number) {
2576 ml.wait();
2577 }
2578 }
2579 };
2580
2581 // DumpMerger merges separate dump files into a complete one
2582 class DumpMerger : public StackObj {
2583 private:
2584 DumpWriter* _writer;
2585 InlinedObjects* _inlined_objects;
2586 const char* _path;
2587 bool _has_error;
2588 int _dump_seq;
2589
2590 private:
2591 void merge_file(const char* path);
2592 void merge_done();
2593 void set_error(const char* msg);
2594
2595 public:
2596 DumpMerger(const char* path, DumpWriter* writer, InlinedObjects* inlined_objects, int dump_seq) :
2597 _writer(writer),
2598 _inlined_objects(inlined_objects),
2599 _path(path),
2600 _has_error(_writer->has_error()),
2601 _dump_seq(dump_seq) {}
2602
2603 void do_merge();
2604
2605 // returns path for the parallel DumpWriter (resource allocated)
2606 static char* get_writer_path(const char* base_path, int seq);
2607
2608 };
2609
2610 char* DumpMerger::get_writer_path(const char* base_path, int seq) {
2611 // approximate required buffer size
2612 size_t buf_size = strlen(base_path)
2613 + 2 // ".p"
2614 + 10 // number (that's enough for 2^32 parallel dumpers)
2615 + 1; // '\0'
2616
2617 char* path = NEW_RESOURCE_ARRAY(char, buf_size);
2618 memset(path, 0, buf_size);
2619
2620 os::snprintf(path, buf_size, "%s.p%d", base_path, seq);
2621
2622 return path;
2623 }
2624
2625
2626 void DumpMerger::merge_done() {
2627 // Writes the HPROF_HEAP_DUMP_END record.
2628 if (!_has_error) {
2629 DumperSupport::end_of_dump(_writer);
2630 _inlined_objects->dump_flat_arrays(_writer);
2631 _writer->flush();
2632 _inlined_objects->release();
2633 }
2634 _dump_seq = 0; //reset
2635 }
2636
2637 void DumpMerger::set_error(const char* msg) {
2638 assert(msg != nullptr, "sanity check");
2639 log_error(heapdump)("%s (file: %s)", msg, _path);
2640 _writer->set_error(msg);
2641 _has_error = true;
2642 }
2643
2644 #ifdef LINUX
2645 // Merge segmented heap files via sendfile, it's more efficient than the
2646 // read+write combination, which would require transferring data to and from
2647 // user space.
2648 void DumpMerger::merge_file(const char* path) {
2649 TraceTime timer("Merge segmented heap file directly", TRACETIME_LOG(Info, heapdump));
2650
2651 int segment_fd = os::open(path, O_RDONLY, 0);
2652 if (segment_fd == -1) {
2653 set_error("Can not open segmented heap file during merging");
2654 return;
2655 }
2656
2657 struct stat st;
2658 if (os::stat(path, &st) != 0) {
2659 ::close(segment_fd);
2660 set_error("Can not get segmented heap file size during merging");
2661 return;
2662 }
2663
2664 // A successful call to sendfile may write fewer bytes than requested; the
2665 // caller should be prepared to retry the call if there were unsent bytes.
2666 jlong offset = 0;
2667 while (offset < st.st_size) {
2668 int ret = os::Linux::sendfile(_writer->get_fd(), segment_fd, &offset, st.st_size);
2669 if (ret == -1) {
2670 ::close(segment_fd);
2671 set_error("Failed to merge segmented heap file");
2672 return;
2673 }
2674 }
2675
2676 // As sendfile variant does not call the write method of the global writer,
2677 // bytes_written is also incorrect for this variant, we need to explicitly
2678 // accumulate bytes_written for the global writer in this case
2679 julong accum = _writer->bytes_written() + st.st_size;
2680 _writer->set_bytes_written(accum);
2681 ::close(segment_fd);
2682 }
2683 #else
2684 // Generic implementation using read+write
2685 void DumpMerger::merge_file(const char* path) {
2686 TraceTime timer("Merge segmented heap file", TRACETIME_LOG(Info, heapdump));
2687
2688 fileStream segment_fs(path, "rb");
2689 if (!segment_fs.is_open()) {
2690 set_error("Can not open segmented heap file during merging");
2691 return;
2692 }
2693
2694 jlong total = 0;
2695 size_t cnt = 0;
2696
2697 // Use _writer buffer for reading.
2698 while ((cnt = segment_fs.read(_writer->buffer(), 1, _writer->buffer_size())) != 0) {
2699 _writer->set_position(cnt);
2700 _writer->flush();
2701 total += cnt;
2702 }
2703
2704 if (segment_fs.fileSize() != total) {
2705 set_error("Merged heap dump is incomplete");
2706 }
2707 }
2708 #endif
2709
2710 void DumpMerger::do_merge() {
2711 TraceTime timer("Merge heap files complete", TRACETIME_LOG(Info, heapdump));
2712
2713 // Since contents in segmented heap file were already zipped, we don't need to zip
2714 // them again during merging.
2715 AbstractCompressor* saved_compressor = _writer->compressor();
2716 _writer->set_compressor(nullptr);
2717
2718 // Merge the content of the remaining files into base file. Regardless of whether
2719 // the merge process is successful or not, these segmented files will be deleted.
2720 for (int i = 0; i < _dump_seq; i++) {
2721 ResourceMark rm;
2722 const char* path = get_writer_path(_path, i);
2723 if (!_has_error) {
2724 merge_file(path);
2725 }
2726 // Delete selected segmented heap file nevertheless
2727 if (remove(path) != 0) {
2728 log_info(heapdump)("Removal of segment file (%d) failed (%d)", i, errno);
2729 }
2730 }
2731
2732 // restore compressor for further use
2733 _writer->set_compressor(saved_compressor);
2734 merge_done();
2735 }
2736
2737 // The VM operation that performs the heap dump
2738 class VM_HeapDumper : public VM_GC_Operation, public WorkerTask, public UnmountedVThreadDumper {
2739 private:
2740 DumpWriter* _writer;
2741 JavaThread* _oome_thread;
2742 Method* _oome_constructor;
2743 bool _gc_before_heap_dump;
2744 GrowableArray<Klass*>* _klass_map;
2745
2746 ThreadDumper** _thread_dumpers; // platform, carrier and mounted virtual threads
2747 int _thread_dumpers_count;
2748 volatile int _thread_serial_num;
2749 volatile int _frame_serial_num;
2750
2751 volatile int _dump_seq;
2752
2753 // Inlined object support.
2754 InlinedObjects _inlined_objects;
2755
2756 // parallel heap dump support
2757 uint _num_dumper_threads;
2758 DumperController* _dumper_controller;
2759 ParallelObjectIterator* _poi;
2760
2761 // Dumper id of VMDumper thread.
2762 static const int VMDumperId = 0;
2763 // VM dumper dumps both heap and non-heap data, other dumpers dump heap-only data.
2764 static bool is_vm_dumper(int dumper_id) { return dumper_id == VMDumperId; }
2765 // the 1st dumper calling get_next_dumper_id becomes VM dumper
2766 int get_next_dumper_id() {
2767 return Atomic::fetch_then_add(&_dump_seq, 1);
2768 }
2769
2770 DumpWriter* writer() const { return _writer; }
2771
2772 bool skip_operation() const;
2773
2774 // HPROF_GC_ROOT_THREAD_OBJ records for platform and mounted virtual threads
2775 void dump_threads(AbstractDumpWriter* writer);
2776
2777 bool is_oom_thread(JavaThread* thread) const {
2778 return thread == _oome_thread && _oome_constructor != nullptr;
2779 }
2780
2781 // HPROF_TRACE and HPROF_FRAME records for platform and mounted virtual threads
2782 void dump_stack_traces(AbstractDumpWriter* writer);
2783
2784 public:
2785 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome, uint num_dump_threads) :
2786 VM_GC_Operation(0 /* total collections, dummy, ignored */,
2787 GCCause::_heap_dump /* GC Cause */,
2788 0 /* total full collections, dummy, ignored */,
2789 gc_before_heap_dump),
2790 WorkerTask("dump heap") {
2791 _writer = writer;
2792 _gc_before_heap_dump = gc_before_heap_dump;
2793 _klass_map = new (mtServiceability) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, mtServiceability);
2794
2795 _thread_dumpers = nullptr;
2796 _thread_dumpers_count = 0;
2797 _thread_serial_num = 1;
2798 _frame_serial_num = 1;
2799
2800 _dump_seq = VMDumperId;
2801 _num_dumper_threads = num_dump_threads;
2802 _dumper_controller = nullptr;
2803 _poi = nullptr;
2804 if (oome) {
2805 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
2806 // get OutOfMemoryError zero-parameter constructor
2807 InstanceKlass* oome_ik = vmClasses::OutOfMemoryError_klass();
2808 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
2809 vmSymbols::void_method_signature());
2810 // get thread throwing OOME when generating the heap dump at OOME
2811 _oome_thread = JavaThread::current();
2812 } else {
2813 _oome_thread = nullptr;
2814 _oome_constructor = nullptr;
2815 }
2816 }
2817
2818 ~VM_HeapDumper() {
2819 if (_thread_dumpers != nullptr) {
2820 for (int i = 0; i < _thread_dumpers_count; i++) {
2821 delete _thread_dumpers[i];
2822 }
2823 FREE_C_HEAP_ARRAY(ThreadDumper*, _thread_dumpers);
2824 }
2825
2826 if (_dumper_controller != nullptr) {
2827 delete _dumper_controller;
2828 _dumper_controller = nullptr;
2829 }
2830 delete _klass_map;
2831 }
2832 int dump_seq() { return _dump_seq; }
2833 bool is_parallel_dump() { return _num_dumper_threads > 1; }
2834 void prepare_parallel_dump(WorkerThreads* workers);
2835
2836 InlinedObjects* inlined_objects() { return &_inlined_objects; }
2837
2838 VMOp_Type type() const { return VMOp_HeapDumper; }
2839 virtual bool doit_prologue();
2840 void doit();
2841 void work(uint worker_id);
2842
2843 // UnmountedVThreadDumper implementation
2844 void dump_vthread(oop vt, AbstractDumpWriter* segment_writer);
2845 };
2846
2847 bool VM_HeapDumper::skip_operation() const {
2848 return false;
2849 }
2850
2851 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2852 void DumperSupport::end_of_dump(AbstractDumpWriter* writer) {
2853 writer->finish_dump_segment();
2854
2855 writer->write_u1(HPROF_HEAP_DUMP_END);
2856 writer->write_u4(0);
2857 writer->write_u4(0);
2858 }
2859
2860 // Write a HPROF_GC_ROOT_THREAD_OBJ record for platform/carrier and mounted virtual threads.
2861 // Then walk the stack so that locals and JNI locals are dumped.
2862 void VM_HeapDumper::dump_threads(AbstractDumpWriter* writer) {
2863 for (int i = 0; i < _thread_dumpers_count; i++) {
2864 _thread_dumpers[i]->dump_thread_obj(writer);
2865 _thread_dumpers[i]->dump_stack_refs(writer);
2866 }
2867 }
2868
2869 bool VM_HeapDumper::doit_prologue() {
2870 if (_gc_before_heap_dump && (UseZGC || UseShenandoahGC)) {
2871 // ZGC and Shenandoah cannot perform a synchronous GC cycle from within the VM thread.
2872 // So collect_as_vm_thread() is a noop. To respect the _gc_before_heap_dump flag a
2873 // synchronous GC cycle is performed from the caller thread in the prologue.
2874 Universe::heap()->collect(GCCause::_heap_dump);
2875 }
2876 return VM_GC_Operation::doit_prologue();
2877 }
2878
2879 void VM_HeapDumper::prepare_parallel_dump(WorkerThreads* workers) {
2880 uint num_active_workers = workers != nullptr ? workers->active_workers() : 0;
2881 uint num_requested_dump_threads = _num_dumper_threads;
2882 // check if we can dump in parallel based on requested and active threads
2883 if (num_active_workers <= 1 || num_requested_dump_threads <= 1) {
2884 _num_dumper_threads = 1;
2885 } else {
2886 _num_dumper_threads = clamp(num_requested_dump_threads, 2U, num_active_workers);
2887 }
2888 _dumper_controller = new (std::nothrow) DumperController(_num_dumper_threads);
2889 bool can_parallel = _num_dumper_threads > 1;
2890 log_info(heapdump)("Requested dump threads %u, active dump threads %u, "
2891 "actual dump threads %u, parallelism %s",
2892 num_requested_dump_threads, num_active_workers,
2893 _num_dumper_threads, can_parallel ? "true" : "false");
2894 }
2895
2896 // The VM operation that dumps the heap. The dump consists of the following
2897 // records:
2898 //
2899 // HPROF_HEADER
2900 // [HPROF_UTF8]*
2901 // [HPROF_LOAD_CLASS]*
2902 // [[HPROF_FRAME]*|HPROF_TRACE]*
2903 // [HPROF_GC_CLASS_DUMP]*
2904 // [HPROF_HEAP_DUMP_SEGMENT]*
2905 // HPROF_HEAP_DUMP_END
2906 //
2907 // The HPROF_TRACE records represent the stack traces where the heap dump
2908 // is generated and a "dummy trace" record which does not include
2909 // any frames. The dummy trace record is used to be referenced as the
2910 // unknown object alloc site.
2911 //
2912 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
2913 // To allow the heap dump be generated in a single pass we remember the position
2914 // of the dump length and fix it up after all sub-records have been written.
2915 // To generate the sub-records we iterate over the heap, writing
2916 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
2917 // records as we go. Once that is done we write records for some of the GC
2918 // roots.
2919
2920 void VM_HeapDumper::doit() {
2921
2922 CollectedHeap* ch = Universe::heap();
2923
2924 ch->ensure_parsability(false); // must happen, even if collection does
2925 // not happen (e.g. due to GCLocker)
2926
2927 if (_gc_before_heap_dump) {
2928 if (GCLocker::is_active()) {
2929 warning("GC locker is held; pre-heapdump GC was skipped");
2930 } else {
2931 ch->collect_as_vm_thread(GCCause::_heap_dump);
2932 }
2933 }
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
2948 void VM_HeapDumper::work(uint worker_id) {
2949 // VM Dumper works on all non-heap data dumping and part of heap iteration.
2950 int dumper_id = get_next_dumper_id();
2951
2952 if (is_vm_dumper(dumper_id)) {
2953 // lock global writer, it will be unlocked after VM Dumper finishes with non-heap data
2954 _dumper_controller->lock_global_writer();
2955 _dumper_controller->signal_start();
2956 } else {
2957 _dumper_controller->wait_for_start_signal();
2958 }
2959
2960 if (is_vm_dumper(dumper_id)) {
2961 TraceTime timer("Dump non-objects", TRACETIME_LOG(Info, heapdump));
2962 // Write the file header - we always use 1.0.2
2963 const char* header = "JAVA PROFILE 1.0.2";
2964
2965 // header is few bytes long - no chance to overflow int
2966 writer()->write_raw(header, strlen(header) + 1); // NUL terminated
2967 writer()->write_u4(oopSize);
2968 // timestamp is current time in ms
2969 writer()->write_u8(os::javaTimeMillis());
2970 // HPROF_UTF8 records
2971 SymbolTableDumper sym_dumper(writer());
2972 SymbolTable::symbols_do(&sym_dumper);
2973
2974 // HPROF_UTF8 records for inlined field names.
2975 inlined_objects()->init();
2976 inlined_objects()->dump_inlined_field_names(writer());
2977
2978 // HPROF_INLINED_FIELDS
2979 inlined_objects()->dump_classed_with_inlined_fields(writer());
2980
2981 // write HPROF_LOAD_CLASS records
2982 {
2983 LoadedClassDumper loaded_class_dumper(writer(), _klass_map);
2984 ClassLoaderDataGraph::classes_do(&loaded_class_dumper);
2985 }
2986
2987 // write HPROF_FRAME and HPROF_TRACE records
2988 // this must be called after _klass_map is built when iterating the classes above.
2989 dump_stack_traces(writer());
2990
2991 // unlock global writer, so parallel dumpers can dump stack traces of unmounted virtual threads
2992 _dumper_controller->unlock_global_writer();
2993 }
2994
2995 // HPROF_HEAP_DUMP/HPROF_HEAP_DUMP_SEGMENT starts here
2996
2997 ResourceMark rm;
2998 // share global compressor, local DumpWriter is not responsible for its life cycle
2999 DumpWriter segment_writer(DumpMerger::get_writer_path(writer()->get_file_path(), dumper_id),
3000 writer()->is_overwrite(), writer()->compressor());
3001 if (!segment_writer.has_error()) {
3002 if (is_vm_dumper(dumper_id)) {
3003 // dump some non-heap subrecords to heap dump segment
3004 TraceTime timer("Dump non-objects (part 2)", TRACETIME_LOG(Info, heapdump));
3005 // Writes HPROF_GC_CLASS_DUMP records
3006 ClassDumper class_dumper(&segment_writer);
3007 ClassLoaderDataGraph::classes_do(&class_dumper);
3008
3009 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
3010 dump_threads(&segment_writer);
3011
3012 // HPROF_GC_ROOT_JNI_GLOBAL
3013 JNIGlobalsDumper jni_dumper(&segment_writer);
3014 JNIHandles::oops_do(&jni_dumper);
3015 // technically not jni roots, but global roots
3016 // for things like preallocated throwable backtraces
3017 Universe::vm_global()->oops_do(&jni_dumper);
3018 // HPROF_GC_ROOT_STICKY_CLASS
3019 // These should be classes in the null class loader data, and not all classes
3020 // if !ClassUnloading
3021 StickyClassDumper stiky_class_dumper(&segment_writer);
3022 ClassLoaderData::the_null_class_loader_data()->classes_do(&stiky_class_dumper);
3023 }
3024
3025 // Heap iteration.
3026 // writes HPROF_GC_INSTANCE_DUMP records.
3027 // After each sub-record is written check_segment_length will be invoked
3028 // to check if the current segment exceeds a threshold. If so, a new
3029 // segment is started.
3030 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
3031 // of the heap dump.
3032
3033 TraceTime timer(is_parallel_dump() ? "Dump heap objects in parallel" : "Dump heap objects", TRACETIME_LOG(Info, heapdump));
3034 HeapObjectDumper obj_dumper(&segment_writer, this);
3035 if (!is_parallel_dump()) {
3036 Universe::heap()->object_iterate(&obj_dumper);
3037 } else {
3038 // == Parallel dump
3039 _poi->object_iterate(&obj_dumper, worker_id);
3040 }
3041
3042 segment_writer.finish_dump_segment();
3043 segment_writer.flush();
3044 }
3045
3046 _dumper_controller->dumper_complete(&segment_writer, writer());
3047
3048 if (is_vm_dumper(dumper_id)) {
3049 _dumper_controller->wait_all_dumpers_complete();
3050
3051 // flush global writer
3052 writer()->flush();
3053
3054 // At this point, all fragments of the heapdump have been written to separate files.
3055 // We need to merge them into a complete heapdump and write HPROF_HEAP_DUMP_END at that time.
3056 }
3057 }
3058
3059 void VM_HeapDumper::dump_stack_traces(AbstractDumpWriter* writer) {
3060 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
3061 DumperSupport::write_header(writer, HPROF_TRACE, 3 * sizeof(u4));
3062 writer->write_u4((u4)STACK_TRACE_ID);
3063 writer->write_u4(0); // thread number
3064 writer->write_u4(0); // frame count
3065
3066 // max number if every platform thread is carrier with mounted virtual thread
3067 _thread_dumpers = NEW_C_HEAP_ARRAY(ThreadDumper*, Threads::number_of_threads() * 2, mtInternal);
3068
3069 for (JavaThreadIteratorWithHandle jtiwh; JavaThread * thread = jtiwh.next(); ) {
3070 if (ThreadDumper::should_dump_pthread(thread)) {
3071 bool add_oom_frame = is_oom_thread(thread);
3072
3073 oop mounted_vt = thread->is_vthread_mounted() ? thread->vthread() : nullptr;
3074 if (mounted_vt != nullptr && !ThreadDumper::should_dump_vthread(mounted_vt)) {
3075 mounted_vt = nullptr;
3076 }
3077
3078 // mounted vthread (if any)
3079 if (mounted_vt != nullptr) {
3080 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::MountedVirtual, thread, mounted_vt);
3081 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3082 if (add_oom_frame) {
3083 thread_dumper->add_oom_frame(_oome_constructor);
3084 // we add oom frame to the VT stack, don't add it to the carrier thread stack
3085 add_oom_frame = false;
3086 }
3087 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3088 thread_dumper->dump_stack_traces(writer, _klass_map);
3089 }
3090
3091 // platform or carrier thread
3092 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::Platform, thread, thread->threadObj());
3093 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3094 if (add_oom_frame) {
3095 thread_dumper->add_oom_frame(_oome_constructor);
3096 }
3097 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3098 thread_dumper->dump_stack_traces(writer, _klass_map);
3099 }
3100 }
3101 }
3102
3103 void VM_HeapDumper::dump_vthread(oop vt, AbstractDumpWriter* segment_writer) {
3104 // unmounted vthread has no JavaThread
3105 ThreadDumper thread_dumper(ThreadDumper::ThreadType::UnmountedVirtual, nullptr, vt);
3106 thread_dumper.init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3107
3108 // write HPROF_TRACE/HPROF_FRAME records to global writer
3109 _dumper_controller->lock_global_writer();
3110 thread_dumper.dump_stack_traces(writer(), _klass_map);
3111 _dumper_controller->unlock_global_writer();
3112
3113 // write HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecord
3114 // to segment writer
3115 thread_dumper.dump_thread_obj(segment_writer);
3116 thread_dumper.dump_stack_refs(segment_writer);
3117 }
3118
3119 // dump the heap to given path.
3120 int HeapDumper::dump(const char* path, outputStream* out, int compression, bool overwrite, uint num_dump_threads) {
3121 assert(path != nullptr && strlen(path) > 0, "path missing");
3122
3123 // print message in interactive case
3124 if (out != nullptr) {
3125 out->print_cr("Dumping heap to %s ...", path);
3126 timer()->start();
3127 }
3128
3129 if (_oome && num_dump_threads > 1) {
3130 // Each additional parallel writer requires several MB of internal memory
3131 // (DumpWriter buffer, DumperClassCacheTable, GZipCompressor buffers).
3132 // For the OOM handling we may already be limited in memory.
3133 // Lets ensure we have at least 20MB per thread.
3134 julong max_threads = os::free_memory() / (20 * M);
3135 if (num_dump_threads > max_threads) {
3136 num_dump_threads = MAX2<uint>(1, (uint)max_threads);
3137 }
3138 }
3139
3140 // create JFR event
3141 EventHeapDump event;
3142
3143 AbstractCompressor* compressor = nullptr;
3144
3145 if (compression > 0) {
3146 compressor = new (std::nothrow) GZipCompressor(compression);
3147
3148 if (compressor == nullptr) {
3149 set_error("Could not allocate gzip compressor");
3150 return -1;
3151 }
3152 }
3153
3154 DumpWriter writer(path, overwrite, compressor);
3155
3156 if (writer.error() != nullptr) {
3157 set_error(writer.error());
3158 if (out != nullptr) {
3159 out->print_cr("Unable to create %s: %s", path,
3160 (error() != nullptr) ? error() : "reason unknown");
3161 }
3162 return -1;
3163 }
3164
3165 // generate the segmented heap dump into separate files
3166 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome, num_dump_threads);
3167 VMThread::execute(&dumper);
3168
3169 // record any error that the writer may have encountered
3170 set_error(writer.error());
3171
3172 // Heap dump process is done in two phases
3173 //
3174 // Phase 1: Concurrent threads directly write heap data to multiple heap files.
3175 // This is done by VM_HeapDumper, which is performed within safepoint.
3176 //
3177 // Phase 2: Merge multiple heap files into one complete heap dump file.
3178 // This is done by DumpMerger, which is performed outside safepoint
3179
3180 DumpMerger merger(path, &writer, dumper.inlined_objects(), dumper.dump_seq());
3181 // Perform heapdump file merge operation in the current thread prevents us
3182 // from occupying the VM Thread, which in turn affects the occurrence of
3183 // GC and other VM operations.
3184 merger.do_merge();
3185 if (writer.error() != nullptr) {
3186 set_error(writer.error());
3187 }
3188
3189 // emit JFR event
3190 if (error() == nullptr) {
3191 event.set_destination(path);
3192 event.set_gcBeforeDump(_gc_before_heap_dump);
3193 event.set_size(writer.bytes_written());
3194 event.set_onOutOfMemoryError(_oome);
3195 event.set_overwrite(overwrite);
3196 event.set_compression(compression);
3197 event.commit();
3198 } else {
3199 log_debug(cds, heap)("Error %s while dumping heap", error());
3200 }
3201
3202 // print message in interactive case
3203 if (out != nullptr) {
3204 timer()->stop();
3205 if (error() == nullptr) {
3206 out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
3207 writer.bytes_written(), timer()->seconds());
3208 } else {
3209 out->print_cr("Dump file is incomplete: %s", writer.error());
3210 }
3211 }
3212
3213 if (compressor != nullptr) {
3214 delete compressor;
3215 }
3216 return (writer.error() == nullptr) ? 0 : -1;
3217 }
3218
3219 // stop timer (if still active), and free any error string we might be holding
3220 HeapDumper::~HeapDumper() {
3221 if (timer()->is_active()) {
3222 timer()->stop();
3223 }
3224 set_error(nullptr);
3225 }
3226
3227
3228 // returns the error string (resource allocated), or null
3229 char* HeapDumper::error_as_C_string() const {
3230 if (error() != nullptr) {
3231 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
3232 strcpy(str, error());
3233 return str;
3234 } else {
3235 return nullptr;
3236 }
3237 }
3238
3239 // set the error string
3240 void HeapDumper::set_error(char const* error) {
3241 if (_error != nullptr) {
3242 os::free(_error);
3243 }
3244 if (error == nullptr) {
3245 _error = nullptr;
3246 } else {
3247 _error = os::strdup(error);
3248 assert(_error != nullptr, "allocation failure");
3249 }
3250 }
3251
3252 // Called by out-of-memory error reporting by a single Java thread
3253 // outside of a JVM safepoint
3254 void HeapDumper::dump_heap_from_oome() {
3255 HeapDumper::dump_heap(true);
3256 }
3257
3258 // Called by error reporting by a single Java thread outside of a JVM safepoint,
3259 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
3260 // callers are strictly serialized and guaranteed not to interfere below. For more
3261 // general use, however, this method will need modification to prevent
3262 // inteference when updating the static variables base_path and dump_file_seq below.
3263 void HeapDumper::dump_heap() {
3264 HeapDumper::dump_heap(false);
3265 }
3266
3267 void HeapDumper::dump_heap(bool oome) {
3268 static char base_path[JVM_MAXPATHLEN] = {'\0'};
3269 static uint dump_file_seq = 0;
3270 char* my_path;
3271 const int max_digit_chars = 20;
3272
3273 const char* dump_file_name = "java_pid";
3274 const char* dump_file_ext = HeapDumpGzipLevel > 0 ? ".hprof.gz" : ".hprof";
3275
3276 // The dump file defaults to java_pid<pid>.hprof in the current working
3277 // directory. HeapDumpPath=<file> can be used to specify an alternative
3278 // dump file name or a directory where dump file is created.
3279 if (dump_file_seq == 0) { // first time in, we initialize base_path
3280 // Calculate potentially longest base path and check if we have enough
3281 // allocated statically.
3282 const size_t total_length =
3283 (HeapDumpPath == nullptr ? 0 : strlen(HeapDumpPath)) +
3284 strlen(os::file_separator()) + max_digit_chars +
3285 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
3286 if (total_length > sizeof(base_path)) {
3287 warning("Cannot create heap dump file. HeapDumpPath is too long.");
3288 return;
3289 }
3290
3291 bool use_default_filename = true;
3292 if (HeapDumpPath == nullptr || HeapDumpPath[0] == '\0') {
3293 // HeapDumpPath=<file> not specified
3294 } else {
3295 strcpy(base_path, HeapDumpPath);
3296 // check if the path is a directory (must exist)
3297 DIR* dir = os::opendir(base_path);
3298 if (dir == nullptr) {
3299 use_default_filename = false;
3300 } else {
3301 // HeapDumpPath specified a directory. We append a file separator
3302 // (if needed).
3303 os::closedir(dir);
3304 size_t fs_len = strlen(os::file_separator());
3305 if (strlen(base_path) >= fs_len) {
3306 char* end = base_path;
3307 end += (strlen(base_path) - fs_len);
3308 if (strcmp(end, os::file_separator()) != 0) {
3309 strcat(base_path, os::file_separator());
3310 }
3311 }
3312 }
3313 }
3314 // If HeapDumpPath wasn't a file name then we append the default name
3315 if (use_default_filename) {
3316 const size_t dlen = strlen(base_path); // if heap dump dir specified
3317 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
3318 dump_file_name, os::current_process_id(), dump_file_ext);
3319 }
3320 const size_t len = strlen(base_path) + 1;
3321 my_path = (char*)os::malloc(len, mtInternal);
3322 if (my_path == nullptr) {
3323 warning("Cannot create heap dump file. Out of system memory.");
3324 return;
3325 }
3326 strncpy(my_path, base_path, len);
3327 } else {
3328 // Append a sequence number id for dumps following the first
3329 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
3330 my_path = (char*)os::malloc(len, mtInternal);
3331 if (my_path == nullptr) {
3332 warning("Cannot create heap dump file. Out of system memory.");
3333 return;
3334 }
3335 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
3336 }
3337 dump_file_seq++; // increment seq number for next time we dump
3338
3339 HeapDumper dumper(false /* no GC before heap dump */,
3340 oome /* pass along out-of-memory-error flag */);
3341 dumper.dump(my_path, tty, HeapDumpGzipLevel);
3342 os::free(my_path);
3343 }