1 /*
2 * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2023, Alibaba Group Holding Limited. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "classfile/classLoaderData.inline.hpp"
28 #include "classfile/classLoaderDataGraph.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "gc/shared/workerThread.hpp"
36 #include "jfr/jfrEvents.hpp"
37 #include "jvm.h"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "memory/universe.hpp"
41 #include "oops/fieldStreams.inline.hpp"
42 #include "oops/klass.inline.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "oops/objArrayOop.inline.hpp"
45 #include "oops/flatArrayKlass.hpp"
46 #include "oops/flatArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/typeArrayOop.inline.hpp"
49 #include "runtime/continuationWrapper.inline.hpp"
50 #include "runtime/fieldDescriptor.inline.hpp"
51 #include "runtime/frame.inline.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/javaThread.inline.hpp"
55 #include "runtime/jniHandles.hpp"
56 #include "runtime/os.hpp"
57 #include "runtime/threads.hpp"
58 #include "runtime/threadSMR.hpp"
59 #include "runtime/vframe.hpp"
60 #include "runtime/vmOperations.hpp"
61 #include "runtime/vmThread.hpp"
62 #include "runtime/timerTrace.hpp"
63 #include "services/heapDumper.hpp"
64 #include "services/heapDumperCompression.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/checkedCast.hpp"
67 #include "utilities/macros.hpp"
68 #include "utilities/ostream.hpp"
69 #ifdef LINUX
70 #include "os_linux.hpp"
71 #endif
72
73 /*
74 * HPROF binary format - description copied from:
75 * src/share/demo/jvmti/hprof/hprof_io.c
76 *
77 *
78 * header "JAVA PROFILE 1.0.2" (0-terminated)
79 *
80 * u4 size of identifiers. Identifiers are used to represent
81 * UTF8 strings, objects, stack traces, etc. They usually
82 * have the same size as host pointers.
83 * u4 high word
84 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
85 * [record]* a sequence of records.
86 *
87 *
88 * Record format:
89 *
90 * u1 a TAG denoting the type of the record
91 * u4 number of *microseconds* since the time stamp in the
92 * header. (wraps around in a little more than an hour)
93 * u4 number of bytes *remaining* in the record. Note that
94 * this number excludes the tag and the length field itself.
95 * [u1]* BODY of the record (a sequence of bytes)
96 *
97 *
98 * The following TAGs are supported:
99 *
100 * TAG BODY notes
101 *----------------------------------------------------------
102 * HPROF_UTF8 a UTF8-encoded name
103 *
104 * id name ID
105 * [u1]* UTF8 characters (no trailing zero)
106 *
107 * HPROF_LOAD_CLASS a newly loaded class
108 *
109 * u4 class serial number (> 0)
110 * id class object ID
111 * u4 stack trace serial number
112 * id class name ID
113 *
114 * HPROF_UNLOAD_CLASS an unloading class
115 *
116 * u4 class serial_number
117 *
118 * HPROF_FRAME a Java stack frame
119 *
120 * id stack frame ID
121 * id method name ID
122 * id method signature ID
123 * id source file name ID
124 * u4 class serial number
125 * i4 line number. >0: normal
126 * -1: unknown
127 * -2: compiled method
128 * -3: native method
129 *
130 * HPROF_TRACE a Java stack trace
131 *
132 * u4 stack trace serial number
133 * u4 thread serial number
134 * u4 number of frames
135 * [id]* stack frame IDs
136 *
137 *
138 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
139 *
140 * u2 flags 0x0001: incremental vs. complete
141 * 0x0002: sorted by allocation vs. live
142 * 0x0004: whether to force a GC
143 * u4 cutoff ratio
144 * u4 total live bytes
145 * u4 total live instances
146 * u8 total bytes allocated
147 * u8 total instances allocated
148 * u4 number of sites that follow
149 * [u1 is_array: 0: normal object
150 * 2: object array
151 * 4: boolean array
152 * 5: char array
153 * 6: float array
154 * 7: double array
155 * 8: byte array
156 * 9: short array
157 * 10: int array
158 * 11: long array
159 * u4 class serial number (may be zero during startup)
160 * u4 stack trace serial number
161 * u4 number of bytes alive
162 * u4 number of instances alive
163 * u4 number of bytes allocated
164 * u4]* number of instance allocated
165 *
166 * HPROF_START_THREAD a newly started thread.
167 *
168 * u4 thread serial number (> 0)
169 * id thread object ID
170 * u4 stack trace serial number
171 * id thread name ID
172 * id thread group name ID
173 * id thread group parent name ID
174 *
175 * HPROF_END_THREAD a terminating thread.
176 *
177 * u4 thread serial number
178 *
179 * HPROF_HEAP_SUMMARY heap summary
180 *
181 * u4 total live bytes
182 * u4 total live instances
183 * u8 total bytes allocated
184 * u8 total instances allocated
185 *
186 * HPROF_HEAP_DUMP denote a heap dump
187 *
188 * [heap dump sub-records]*
189 *
190 * There are four kinds of heap dump sub-records:
191 *
192 * u1 sub-record type
193 *
194 * HPROF_GC_ROOT_UNKNOWN unknown root
195 *
196 * id object ID
197 *
198 * HPROF_GC_ROOT_THREAD_OBJ thread object
199 *
200 * id thread object ID (may be 0 for a
201 * thread newly attached through JNI)
202 * u4 thread sequence number
203 * u4 stack trace sequence number
204 *
205 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
206 *
207 * id object ID
208 * id JNI global ref ID
209 *
210 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
211 *
212 * id object ID
213 * u4 thread serial number
214 * u4 frame # in stack trace (-1 for empty)
215 *
216 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
217 *
218 * id object ID
219 * u4 thread serial number
220 * u4 frame # in stack trace (-1 for empty)
221 *
222 * HPROF_GC_ROOT_NATIVE_STACK Native stack
223 *
224 * id object ID
225 * u4 thread serial number
226 *
227 * HPROF_GC_ROOT_STICKY_CLASS System class
228 *
229 * id object ID
230 *
231 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
232 *
233 * id object ID
234 * u4 thread serial number
235 *
236 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
237 *
238 * id object ID
239 *
240 * HPROF_GC_CLASS_DUMP dump of a class object
241 *
242 * id class object ID
243 * u4 stack trace serial number
244 * id super class object ID
245 * id class loader object ID
246 * id signers object ID
247 * id protection domain object ID
248 * id reserved
249 * id reserved
250 *
251 * u4 instance size (in bytes)
252 *
253 * u2 size of constant pool
254 * [u2, constant pool index,
255 * ty, type
256 * 2: object
257 * 4: boolean
258 * 5: char
259 * 6: float
260 * 7: double
261 * 8: byte
262 * 9: short
263 * 10: int
264 * 11: long
265 * vl]* and value
266 *
267 * u2 number of static fields
268 * [id, static field name,
269 * ty, type,
270 * vl]* and value
271 *
272 * u2 number of inst. fields (not inc. super)
273 * [id, instance field name,
274 * ty]* type
275 *
276 * HPROF_GC_INSTANCE_DUMP dump of a normal object
277 *
278 * id object ID
279 * u4 stack trace serial number
280 * id class object ID
281 * u4 number of bytes that follow
282 * [vl]* instance field values (class, followed
283 * by super, super's super ...)
284 *
285 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
286 *
287 * id array object ID
288 * u4 stack trace serial number
289 * u4 number of elements
290 * id array class ID
291 * [id]* elements
292 *
293 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
294 *
295 * id array object ID
296 * u4 stack trace serial number
297 * u4 number of elements
298 * u1 element type
299 * 4: boolean array
300 * 5: char array
301 * 6: float array
302 * 7: double array
303 * 8: byte array
304 * 9: short array
305 * 10: int array
306 * 11: long array
307 * [u1]* elements
308 *
309 * HPROF_CPU_SAMPLES a set of sample traces of running threads
310 *
311 * u4 total number of samples
312 * u4 # of traces
313 * [u4 # of samples
314 * u4]* stack trace serial number
315 *
316 * HPROF_CONTROL_SETTINGS the settings of on/off switches
317 *
318 * u4 0x00000001: alloc traces on/off
319 * 0x00000002: cpu sampling on/off
320 * u2 stack trace depth
321 *
322 * HPROF_FLAT_ARRAYS list of flat arrays
323 *
324 * [flat array sub-records]*
325 *
326 * HPROF_FLAT_ARRAY flat array
327 *
328 * id array object ID (dumped as HPROF_GC_PRIM_ARRAY_DUMP)
329 * id element class ID (dumped by HPROF_GC_CLASS_DUMP)
330 *
331 * HPROF_INLINED_FIELDS decribes inlined fields
332 *
333 * [class with inlined fields sub-records]*
334 *
335 * HPROF_CLASS_WITH_INLINED_FIELDS
336 *
337 * id class ID (dumped as HPROF_GC_CLASS_DUMP)
338 *
339 * u2 number of instance inlined fields (not including super)
340 * [u2, inlined field index,
341 * u2, synthetic field count,
342 * id, original field name,
343 * id]* inlined field class ID (dumped by HPROF_GC_CLASS_DUMP)
344 *
345 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
346 * be generated as a sequence of heap dump segments. This sequence is
347 * terminated by an end record. The additional tags allowed by format
348 * "JAVA PROFILE 1.0.2" are:
349 *
350 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
351 *
352 * [heap dump sub-records]*
353 * The same sub-record types allowed by HPROF_HEAP_DUMP
354 *
355 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
356 *
357 */
358
359
360 // HPROF tags
361
362 enum hprofTag : u1 {
363 // top-level records
364 HPROF_UTF8 = 0x01,
365 HPROF_LOAD_CLASS = 0x02,
366 HPROF_UNLOAD_CLASS = 0x03,
367 HPROF_FRAME = 0x04,
368 HPROF_TRACE = 0x05,
369 HPROF_ALLOC_SITES = 0x06,
370 HPROF_HEAP_SUMMARY = 0x07,
371 HPROF_START_THREAD = 0x0A,
372 HPROF_END_THREAD = 0x0B,
373 HPROF_HEAP_DUMP = 0x0C,
374 HPROF_CPU_SAMPLES = 0x0D,
375 HPROF_CONTROL_SETTINGS = 0x0E,
376
377 // 1.0.2 record types
378 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
379 HPROF_HEAP_DUMP_END = 0x2C,
380
381 // inlined object support
382 HPROF_FLAT_ARRAYS = 0x12,
383 HPROF_INLINED_FIELDS = 0x13,
384 // inlined object subrecords
385 HPROF_FLAT_ARRAY = 0x01,
386 HPROF_CLASS_WITH_INLINED_FIELDS = 0x01,
387
388 // field types
389 HPROF_ARRAY_OBJECT = 0x01,
390 HPROF_NORMAL_OBJECT = 0x02,
391 HPROF_BOOLEAN = 0x04,
392 HPROF_CHAR = 0x05,
393 HPROF_FLOAT = 0x06,
394 HPROF_DOUBLE = 0x07,
395 HPROF_BYTE = 0x08,
396 HPROF_SHORT = 0x09,
397 HPROF_INT = 0x0A,
398 HPROF_LONG = 0x0B,
399
400 // data-dump sub-records
401 HPROF_GC_ROOT_UNKNOWN = 0xFF,
402 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
403 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
404 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
405 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
406 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
407 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
408 HPROF_GC_ROOT_MONITOR_USED = 0x07,
409 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
410 HPROF_GC_CLASS_DUMP = 0x20,
411 HPROF_GC_INSTANCE_DUMP = 0x21,
412 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
413 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
414 };
415
416 // Default stack trace ID (used for dummy HPROF_TRACE record)
417 enum {
418 STACK_TRACE_ID = 1,
419 INITIAL_CLASS_COUNT = 200
420 };
421
422
423 class AbstractDumpWriter;
424
425 class InlinedObjects {
426
427 struct ClassInlinedFields {
428 const Klass *klass;
429 uintx base_index; // base index of the inlined field names (1st field has index base_index+1).
430 ClassInlinedFields(const Klass *klass = nullptr, uintx base_index = 0) : klass(klass), base_index(base_index) {}
431
432 // For GrowableArray::find_sorted().
433 static int compare(const ClassInlinedFields& a, const ClassInlinedFields& b) {
434 return a.klass - b.klass;
435 }
436 // For GrowableArray::sort().
437 static int compare(ClassInlinedFields* a, ClassInlinedFields* b) {
438 return compare(*a, *b);
439 }
440 };
441
442 uintx _min_string_id;
443 uintx _max_string_id;
444
445 GrowableArray<ClassInlinedFields> *_inlined_field_map;
446
447 // counters for classes with inlined fields and for the fields
448 int _classes_count;
449 int _inlined_fields_count;
450
451 static InlinedObjects *_instance;
452
453 static void inlined_field_names_callback(InlinedObjects* _this, const Klass *klass, uintx base_index, int count);
454
455 GrowableArray<oop> *_flat_arrays;
456
457 public:
458 InlinedObjects()
459 : _min_string_id(0), _max_string_id(0),
460 _inlined_field_map(nullptr),
461 _classes_count(0), _inlined_fields_count(0),
462 _flat_arrays(nullptr) {
463 }
464
465 static InlinedObjects* get_instance() {
466 return _instance;
467 }
468
469 void init();
470 void release();
471
472 void dump_inlined_field_names(AbstractDumpWriter *writer);
473
474 uintx get_base_index_for(Klass* k);
475 uintx get_next_string_id(uintx id);
476
477 void dump_classed_with_inlined_fields(AbstractDumpWriter* writer);
478
479 void add_flat_array(oop array);
480 void dump_flat_arrays(AbstractDumpWriter* writer);
481
482 };
483
484 InlinedObjects *InlinedObjects::_instance = nullptr;
485
486
487 // Supports I/O operations for a dump
488 // Base class for dump and parallel dump
489 class AbstractDumpWriter : public CHeapObj<mtInternal> {
490 protected:
491 enum {
492 io_buffer_max_size = 1*M,
493 dump_segment_header_size = 9
494 };
495
496 char* _buffer; // internal buffer
497 size_t _size;
498 size_t _pos;
499
500 bool _in_dump_segment; // Are we currently in a dump segment?
501 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
502 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
503 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
504
505 char* buffer() const { return _buffer; }
506 size_t buffer_size() const { return _size; }
507 void set_position(size_t pos) { _pos = pos; }
508
509 // Can be called if we have enough room in the buffer.
510 void write_fast(const void* s, size_t len);
511
512 // Returns true if we have enough room in the buffer for 'len' bytes.
513 bool can_write_fast(size_t len);
514
515 void write_address(address a);
516
517 public:
518 AbstractDumpWriter() :
519 _buffer(nullptr),
520 _size(io_buffer_max_size),
521 _pos(0),
522 _in_dump_segment(false) { }
523
524 // Total number of bytes written to the disk
525 virtual julong bytes_written() const = 0;
526 // Return non-null if error occurred
527 virtual char const* error() const = 0;
528
529 size_t position() const { return _pos; }
530 // writer functions
531 virtual void write_raw(const void* s, size_t len);
532 void write_u1(u1 x);
533 void write_u2(u2 x);
534 void write_u4(u4 x);
535 void write_u8(u8 x);
536 void write_objectID(oop o);
537 void write_rootID(oop* p);
538 void write_symbolID(Symbol* o);
539 void write_classID(Klass* k);
540 void write_id(u4 x);
541
542 // Start a new sub-record. Starts a new heap dump segment if needed.
543 void start_sub_record(u1 tag, u4 len);
544 // Ends the current sub-record.
545 void end_sub_record();
546 // Finishes the current dump segment if not already finished.
547 void finish_dump_segment();
548 // Flush internal buffer to persistent storage
549 virtual void flush() = 0;
550 };
551
552 void AbstractDumpWriter::write_fast(const void* s, size_t len) {
553 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
554 assert(buffer_size() - position() >= len, "Must fit");
555 debug_only(_sub_record_left -= len);
556 memcpy(buffer() + position(), s, len);
557 set_position(position() + len);
558 }
559
560 bool AbstractDumpWriter::can_write_fast(size_t len) {
561 return buffer_size() - position() >= len;
562 }
563
564 // write raw bytes
565 void AbstractDumpWriter::write_raw(const void* s, size_t len) {
566 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
567 debug_only(_sub_record_left -= len);
568
569 // flush buffer to make room.
570 while (len > buffer_size() - position()) {
571 assert(!_in_dump_segment || _is_huge_sub_record,
572 "Cannot overflow in non-huge sub-record.");
573 size_t to_write = buffer_size() - position();
574 memcpy(buffer() + position(), s, to_write);
575 s = (void*) ((char*) s + to_write);
576 len -= to_write;
577 set_position(position() + to_write);
578 flush();
579 }
580
581 memcpy(buffer() + position(), s, len);
582 set_position(position() + len);
583 }
584
585 // Makes sure we inline the fast write into the write_u* functions. This is a big speedup.
586 #define WRITE_KNOWN_TYPE(p, len) do { if (can_write_fast((len))) write_fast((p), (len)); \
587 else write_raw((p), (len)); } while (0)
588
589 void AbstractDumpWriter::write_u1(u1 x) {
590 WRITE_KNOWN_TYPE(&x, 1);
591 }
592
593 void AbstractDumpWriter::write_u2(u2 x) {
594 u2 v;
595 Bytes::put_Java_u2((address)&v, x);
596 WRITE_KNOWN_TYPE(&v, 2);
597 }
598
599 void AbstractDumpWriter::write_u4(u4 x) {
600 u4 v;
601 Bytes::put_Java_u4((address)&v, x);
602 WRITE_KNOWN_TYPE(&v, 4);
603 }
604
605 void AbstractDumpWriter::write_u8(u8 x) {
606 u8 v;
607 Bytes::put_Java_u8((address)&v, x);
608 WRITE_KNOWN_TYPE(&v, 8);
609 }
610
611 void AbstractDumpWriter::write_address(address a) {
612 #ifdef _LP64
613 write_u8((u8)a);
614 #else
615 write_u4((u4)a);
616 #endif
617 }
618
619 void AbstractDumpWriter::write_objectID(oop o) {
620 write_address(cast_from_oop<address>(o));
621 }
622
623 void AbstractDumpWriter::write_rootID(oop* p) {
624 write_address((address)p);
625 }
626
627 void AbstractDumpWriter::write_symbolID(Symbol* s) {
628 write_address((address)((uintptr_t)s));
629 }
630
631 void AbstractDumpWriter::write_id(u4 x) {
632 #ifdef _LP64
633 write_u8((u8) x);
634 #else
635 write_u4(x);
636 #endif
637 }
638
639 // We use java mirror as the class ID
640 void AbstractDumpWriter::write_classID(Klass* k) {
641 write_objectID(k->java_mirror());
642 }
643
644 void AbstractDumpWriter::finish_dump_segment() {
645 if (_in_dump_segment) {
646 assert(_sub_record_left == 0, "Last sub-record not written completely");
647 assert(_sub_record_ended, "sub-record must have ended");
648
649 // Fix up the dump segment length if we haven't written a huge sub-record last
650 // (in which case the segment length was already set to the correct value initially).
651 if (!_is_huge_sub_record) {
652 assert(position() > dump_segment_header_size, "Dump segment should have some content");
653 Bytes::put_Java_u4((address) (buffer() + 5),
654 (u4) (position() - dump_segment_header_size));
655 } else {
656 // Finish process huge sub record
657 // Set _is_huge_sub_record to false so the parallel dump writer can flush data to file.
658 _is_huge_sub_record = false;
659 }
660
661 _in_dump_segment = false;
662 flush();
663 }
664 }
665
666 void AbstractDumpWriter::start_sub_record(u1 tag, u4 len) {
667 if (!_in_dump_segment) {
668 if (position() > 0) {
669 flush();
670 }
671
672 assert(position() == 0 && buffer_size() > dump_segment_header_size, "Must be at the start");
673
674 write_u1(HPROF_HEAP_DUMP_SEGMENT);
675 write_u4(0); // timestamp
676 // Will be fixed up later if we add more sub-records. If this is a huge sub-record,
677 // this is already the correct length, since we don't add more sub-records.
678 write_u4(len);
679 assert(Bytes::get_Java_u4((address)(buffer() + 5)) == len, "Inconsistent size!");
680 _in_dump_segment = true;
681 _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
682 } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
683 // This object will not fit in completely or the last sub-record was huge.
684 // Finish the current segment and try again.
685 finish_dump_segment();
686 start_sub_record(tag, len);
687
688 return;
689 }
690
691 debug_only(_sub_record_left = len);
692 debug_only(_sub_record_ended = false);
693
694 write_u1(tag);
695 }
696
697 void AbstractDumpWriter::end_sub_record() {
698 assert(_in_dump_segment, "must be in dump segment");
699 assert(_sub_record_left == 0, "sub-record not written completely");
700 assert(!_sub_record_ended, "Must not have ended yet");
701 debug_only(_sub_record_ended = true);
702 }
703
704 // Supports I/O operations for a dump
705
706 class DumpWriter : public AbstractDumpWriter {
707 private:
708 FileWriter* _writer;
709 AbstractCompressor* _compressor;
710 size_t _bytes_written;
711 char* _error;
712 // Compression support
713 char* _out_buffer;
714 size_t _out_size;
715 size_t _out_pos;
716 char* _tmp_buffer;
717 size_t _tmp_size;
718
719 private:
720 void do_compress();
721
722 public:
723 DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor);
724 ~DumpWriter();
725 julong bytes_written() const override { return (julong) _bytes_written; }
726 void set_bytes_written(julong bytes_written) { _bytes_written = bytes_written; }
727 char const* error() const override { return _error; }
728 void set_error(const char* error) { _error = (char*)error; }
729 bool has_error() const { return _error != nullptr; }
730 const char* get_file_path() const { return _writer->get_file_path(); }
731 AbstractCompressor* compressor() { return _compressor; }
732 void set_compressor(AbstractCompressor* p) { _compressor = p; }
733 bool is_overwrite() const { return _writer->is_overwrite(); }
734 int get_fd() const { return _writer->get_fd(); }
735
736 void flush() override;
737 };
738
739 DumpWriter::DumpWriter(const char* path, bool overwrite, AbstractCompressor* compressor) :
740 AbstractDumpWriter(),
741 _writer(new (std::nothrow) FileWriter(path, overwrite)),
742 _compressor(compressor),
743 _bytes_written(0),
744 _error(nullptr),
745 _out_buffer(nullptr),
746 _out_size(0),
747 _out_pos(0),
748 _tmp_buffer(nullptr),
749 _tmp_size(0) {
750 _error = (char*)_writer->open_writer();
751 if (_error == nullptr) {
752 _buffer = (char*)os::malloc(io_buffer_max_size, mtInternal);
753 if (compressor != nullptr) {
754 _error = (char*)_compressor->init(io_buffer_max_size, &_out_size, &_tmp_size);
755 if (_error == nullptr) {
756 if (_out_size > 0) {
757 _out_buffer = (char*)os::malloc(_out_size, mtInternal);
758 }
759 if (_tmp_size > 0) {
760 _tmp_buffer = (char*)os::malloc(_tmp_size, mtInternal);
761 }
762 }
763 }
764 }
765 // initialize internal buffer
766 _pos = 0;
767 _size = io_buffer_max_size;
768 }
769
770 DumpWriter::~DumpWriter(){
771 if (_buffer != nullptr) {
772 os::free(_buffer);
773 }
774 if (_out_buffer != nullptr) {
775 os::free(_out_buffer);
776 }
777 if (_tmp_buffer != nullptr) {
778 os::free(_tmp_buffer);
779 }
780 if (_writer != nullptr) {
781 delete _writer;
782 }
783 _bytes_written = -1;
784 }
785
786 // flush any buffered bytes to the file
787 void DumpWriter::flush() {
788 if (_pos <= 0) {
789 return;
790 }
791 if (has_error()) {
792 _pos = 0;
793 return;
794 }
795 char* result = nullptr;
796 if (_compressor == nullptr) {
797 result = (char*)_writer->write_buf(_buffer, _pos);
798 _bytes_written += _pos;
799 } else {
800 do_compress();
801 if (!has_error()) {
802 result = (char*)_writer->write_buf(_out_buffer, _out_pos);
803 _bytes_written += _out_pos;
804 }
805 }
806 _pos = 0; // reset pos to make internal buffer available
807
808 if (result != nullptr) {
809 set_error(result);
810 }
811 }
812
813 void DumpWriter::do_compress() {
814 const char* msg = _compressor->compress(_buffer, _pos, _out_buffer, _out_size,
815 _tmp_buffer, _tmp_size, &_out_pos);
816
817 if (msg != nullptr) {
818 set_error(msg);
819 }
820 }
821
822 class DumperClassCacheTable;
823 class DumperClassCacheTableEntry;
824
825 // Support class with a collection of functions used when dumping the heap
826 class DumperSupport : AllStatic {
827 public:
828
829 // write a header of the given type
830 static void write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len);
831
832 // returns hprof tag for the given type signature
833 static hprofTag sig2tag(Symbol* sig);
834 // returns hprof tag for the given basic type
835 static hprofTag type2tag(BasicType type);
836 // Returns the size of the data to write.
837 static u4 sig2size(Symbol* sig);
838
839 // calculates the total size of the all fields of the given class.
840 static u4 instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry = nullptr);
841
842 // dump a jfloat
843 static void dump_float(AbstractDumpWriter* writer, jfloat f);
844 // dump a jdouble
845 static void dump_double(AbstractDumpWriter* writer, jdouble d);
846 // dumps the raw value of the given field
847 static void dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset);
848 // returns the size of the static fields; also counts the static fields
849 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
850 // dumps static fields of the given class
851 static void dump_static_fields(AbstractDumpWriter* writer, Klass* k);
852 // dump the raw values of the instance fields of the given identity or inlined object;
853 // for identity objects offset is 0 and 'klass' is o->klass(),
854 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class
855 static void dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
856 // dump the raw values of the instance fields of the given inlined object;
857 // dump_instance_fields wrapper for inlined objects
858 static void dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
859
860 // get the count of the instance fields for a given class
861 static u2 get_instance_fields_count(InstanceKlass* ik);
862 // dumps the definition of the instance fields for a given class
863 static void dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* k, uintx *inlined_fields_index = nullptr);
864 // creates HPROF_GC_INSTANCE_DUMP record for the given object
865 static void dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache);
866 // creates HPROF_GC_CLASS_DUMP record for the given instance class
867 static void dump_instance_class(AbstractDumpWriter* writer, Klass* k);
868 // creates HPROF_GC_CLASS_DUMP record for a given array class
869 static void dump_array_class(AbstractDumpWriter* writer, Klass* k);
870
871 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
872 static void dump_object_array(AbstractDumpWriter* writer, objArrayOop array);
873 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
874 static void dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache);
875 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
876 static void dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array);
877 // create HPROF_FRAME record for the given method and bci
878 static void dump_stack_frame(AbstractDumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
879
880 // check if we need to truncate an array
881 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size);
882 // extended version to dump flat arrays as primitive arrays;
883 // type_size specifies size of the inlined objects.
884 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size);
885
886 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
887 static void end_of_dump(AbstractDumpWriter* writer);
888
889 static oop mask_dormant_archived_object(oop o, oop ref_obj) {
890 if (o != nullptr && o->klass()->java_mirror_no_keepalive() == nullptr) {
891 // Ignore this object since the corresponding java mirror is not loaded.
892 // Might be a dormant archive object.
893 report_dormant_archived_object(o, ref_obj);
894 return nullptr;
895 } else {
896 return o;
897 }
898 }
899
900 // helper methods for inlined fields.
901 static bool is_inlined_field(const fieldDescriptor& fld) {
902 return fld.is_flat();
903 }
904 static InlineKlass* get_inlined_field_klass(const fieldDescriptor& fld) {
905 assert(is_inlined_field(fld), "must be inlined field");
906 InstanceKlass* holder_klass = fld.field_holder();
907 return InlineKlass::cast(holder_klass->get_inline_type_field_klass(fld.index()));
908 }
909
910 static void report_dormant_archived_object(oop o, oop ref_obj) {
911 if (log_is_enabled(Trace, cds, heap)) {
912 ResourceMark rm;
913 if (ref_obj != nullptr) {
914 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
915 p2i(o), o->klass()->external_name(),
916 p2i(ref_obj), ref_obj->klass()->external_name());
917 } else {
918 log_trace(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)",
919 p2i(o), o->klass()->external_name());
920 }
921 }
922 }
923 };
924
925 // Hash table of klasses to the klass metadata. This should greatly improve the
926 // hash dumping performance. This hash table is supposed to be used by a single
927 // thread only.
928 //
929 class DumperClassCacheTableEntry : public CHeapObj<mtServiceability> {
930 friend class DumperClassCacheTable;
931 private:
932 GrowableArray<char> _sigs_start;
933 GrowableArray<int> _offsets;
934 GrowableArray<InlineKlass*> _inline_klasses;
935 u4 _instance_size;
936 int _entries;
937
938 public:
939 DumperClassCacheTableEntry() : _instance_size(0), _entries(0) {};
940
941 int field_count() { return _entries; }
942 char sig_start(int field_idx) { return _sigs_start.at(field_idx); }
943 void push_sig_start_inlined() { _sigs_start.push('Q'); }
944 bool is_inlined(int field_idx){ return _sigs_start.at(field_idx) == 'Q'; }
945 InlineKlass* inline_klass(int field_idx) { assert(is_inlined(field_idx), "Not inlined"); return _inline_klasses.at(field_idx); }
946 int offset(int field_idx) { return _offsets.at(field_idx); }
947 u4 instance_size() { return _instance_size; }
948 };
949
950 class DumperClassCacheTable {
951 private:
952 // ResourceHashtable SIZE is specified at compile time so we
953 // use 1031 which is the first prime after 1024.
954 static constexpr size_t TABLE_SIZE = 1031;
955
956 // Maintain the cache for N classes. This limits memory footprint
957 // impact, regardless of how many classes we have in the dump.
958 // This also improves look up performance by keeping the statically
959 // sized table from overloading.
960 static constexpr int CACHE_TOP = 256;
961
962 typedef ResourceHashtable<InstanceKlass*, DumperClassCacheTableEntry*,
963 TABLE_SIZE, AnyObj::C_HEAP, mtServiceability> PtrTable;
964 PtrTable* _ptrs;
965
966 // Single-slot cache to handle the major case of objects of the same
967 // class back-to-back, e.g. from T[].
968 InstanceKlass* _last_ik;
969 DumperClassCacheTableEntry* _last_entry;
970
971 void unlink_all(PtrTable* table) {
972 class CleanupEntry: StackObj {
973 public:
974 bool do_entry(InstanceKlass*& key, DumperClassCacheTableEntry*& entry) {
975 delete entry;
976 return true;
977 }
978 } cleanup;
979 table->unlink(&cleanup);
980 }
981
982 public:
983 DumperClassCacheTableEntry* lookup_or_create(InstanceKlass* ik) {
984 if (_last_ik == ik) {
985 return _last_entry;
986 }
987
988 DumperClassCacheTableEntry* entry;
989 DumperClassCacheTableEntry** from_cache = _ptrs->get(ik);
990 if (from_cache == nullptr) {
991 entry = new DumperClassCacheTableEntry();
992 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
993 if (!fld.access_flags().is_static()) {
994 InlineKlass* inlineKlass = nullptr;
995 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
996 inlineKlass = DumperSupport::get_inlined_field_klass(fld.field_descriptor());
997 entry->push_sig_start_inlined();
998 entry->_instance_size += DumperSupport::instance_size(inlineKlass);
999 } else {
1000 Symbol* sig = fld.signature();
1001 entry->_sigs_start.push(sig->char_at(0));
1002 entry->_instance_size += DumperSupport::sig2size(sig);
1003 }
1004 entry->_inline_klasses.push(inlineKlass);
1005 entry->_offsets.push(fld.offset());
1006 entry->_entries++;
1007 }
1008 }
1009
1010 if (_ptrs->number_of_entries() >= CACHE_TOP) {
1011 // We do not track the individual hit rates for table entries.
1012 // Purge the entire table, and let the cache catch up with new
1013 // distribution.
1014 unlink_all(_ptrs);
1015 }
1016
1017 _ptrs->put(ik, entry);
1018 } else {
1019 entry = *from_cache;
1020 }
1021
1022 // Remember for single-slot cache.
1023 _last_ik = ik;
1024 _last_entry = entry;
1025
1026 return entry;
1027 }
1028
1029 DumperClassCacheTable() : _ptrs(new (mtServiceability) PtrTable), _last_ik(nullptr), _last_entry(nullptr) {}
1030
1031 ~DumperClassCacheTable() {
1032 unlink_all(_ptrs);
1033 delete _ptrs;
1034 }
1035 };
1036
1037 // write a header of the given type
1038 void DumperSupport:: write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len) {
1039 writer->write_u1(tag);
1040 writer->write_u4(0); // current ticks
1041 writer->write_u4(len);
1042 }
1043
1044 // returns hprof tag for the given type signature
1045 hprofTag DumperSupport::sig2tag(Symbol* sig) {
1046 switch (sig->char_at(0)) {
1047 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
1048 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
1049 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
1050 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
1051 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
1052 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
1053 case JVM_SIGNATURE_INT : return HPROF_INT;
1054 case JVM_SIGNATURE_LONG : return HPROF_LONG;
1055 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
1056 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
1057 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1058 }
1059 }
1060
1061 hprofTag DumperSupport::type2tag(BasicType type) {
1062 switch (type) {
1063 case T_BYTE : return HPROF_BYTE;
1064 case T_CHAR : return HPROF_CHAR;
1065 case T_FLOAT : return HPROF_FLOAT;
1066 case T_DOUBLE : return HPROF_DOUBLE;
1067 case T_INT : return HPROF_INT;
1068 case T_LONG : return HPROF_LONG;
1069 case T_SHORT : return HPROF_SHORT;
1070 case T_BOOLEAN : return HPROF_BOOLEAN;
1071 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1072 }
1073 }
1074
1075 u4 DumperSupport::sig2size(Symbol* sig) {
1076 switch (sig->char_at(0)) {
1077 case JVM_SIGNATURE_CLASS:
1078 case JVM_SIGNATURE_ARRAY: return sizeof(address);
1079 case JVM_SIGNATURE_BOOLEAN:
1080 case JVM_SIGNATURE_BYTE: return 1;
1081 case JVM_SIGNATURE_SHORT:
1082 case JVM_SIGNATURE_CHAR: return 2;
1083 case JVM_SIGNATURE_INT:
1084 case JVM_SIGNATURE_FLOAT: return 4;
1085 case JVM_SIGNATURE_LONG:
1086 case JVM_SIGNATURE_DOUBLE: return 8;
1087 default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
1088 }
1089 }
1090
1091 template<typename T, typename F> T bit_cast(F from) { // replace with the real thing when we can use c++20
1092 T to;
1093 static_assert(sizeof(to) == sizeof(from), "must be of the same size");
1094 memcpy(&to, &from, sizeof(to));
1095 return to;
1096 }
1097
1098 // dump a jfloat
1099 void DumperSupport::dump_float(AbstractDumpWriter* writer, jfloat f) {
1100 if (g_isnan(f)) {
1101 writer->write_u4(0x7fc00000); // collapsing NaNs
1102 } else {
1103 writer->write_u4(bit_cast<u4>(f));
1104 }
1105 }
1106
1107 // dump a jdouble
1108 void DumperSupport::dump_double(AbstractDumpWriter* writer, jdouble d) {
1109 if (g_isnan(d)) {
1110 writer->write_u8(0x7ff80000ull << 32); // collapsing NaNs
1111 } else {
1112 writer->write_u8(bit_cast<u8>(d));
1113 }
1114 }
1115
1116
1117 // dumps the raw value of the given field
1118 void DumperSupport::dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset) {
1119 switch (type) {
1120 case JVM_SIGNATURE_CLASS :
1121 case JVM_SIGNATURE_ARRAY : {
1122 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
1123 o = mask_dormant_archived_object(o, obj);
1124 assert(oopDesc::is_oop_or_null(o), "Expected an oop or nullptr at " PTR_FORMAT, p2i(o));
1125 writer->write_objectID(o);
1126 break;
1127 }
1128 case JVM_SIGNATURE_BYTE : {
1129 jbyte b = obj->byte_field(offset);
1130 writer->write_u1(b);
1131 break;
1132 }
1133 case JVM_SIGNATURE_CHAR : {
1134 jchar c = obj->char_field(offset);
1135 writer->write_u2(c);
1136 break;
1137 }
1138 case JVM_SIGNATURE_SHORT : {
1139 jshort s = obj->short_field(offset);
1140 writer->write_u2(s);
1141 break;
1142 }
1143 case JVM_SIGNATURE_FLOAT : {
1144 jfloat f = obj->float_field(offset);
1145 dump_float(writer, f);
1146 break;
1147 }
1148 case JVM_SIGNATURE_DOUBLE : {
1149 jdouble d = obj->double_field(offset);
1150 dump_double(writer, d);
1151 break;
1152 }
1153 case JVM_SIGNATURE_INT : {
1154 jint i = obj->int_field(offset);
1155 writer->write_u4(i);
1156 break;
1157 }
1158 case JVM_SIGNATURE_LONG : {
1159 jlong l = obj->long_field(offset);
1160 writer->write_u8(l);
1161 break;
1162 }
1163 case JVM_SIGNATURE_BOOLEAN : {
1164 jboolean b = obj->bool_field(offset);
1165 writer->write_u1(b);
1166 break;
1167 }
1168 default : {
1169 ShouldNotReachHere();
1170 break;
1171 }
1172 }
1173 }
1174
1175 // calculates the total size of the all fields of the given class.
1176 u4 DumperSupport::instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry) {
1177 if (class_cache_entry != nullptr) {
1178 return class_cache_entry->instance_size();
1179 } else {
1180 u4 size = 0;
1181 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1182 if (!fld.access_flags().is_static()) {
1183 if (is_inlined_field(fld.field_descriptor())) {
1184 size += instance_size(get_inlined_field_klass(fld.field_descriptor()));
1185 } else {
1186 size += sig2size(fld.signature());
1187 }
1188 }
1189 }
1190 return size;
1191 }
1192 }
1193
1194 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1195 field_count = 0;
1196 u4 size = 0;
1197
1198 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1199 if (fldc.access_flags().is_static()) {
1200 assert(!is_inlined_field(fldc.field_descriptor()), "static fields cannot be inlined");
1201
1202 field_count++;
1203 size += sig2size(fldc.signature());
1204 }
1205 }
1206
1207 // Add in resolved_references which is referenced by the cpCache
1208 // The resolved_references is an array per InstanceKlass holding the
1209 // strings and other oops resolved from the constant pool.
1210 oop resolved_references = ik->constants()->resolved_references_or_null();
1211 if (resolved_references != nullptr) {
1212 field_count++;
1213 size += sizeof(address);
1214
1215 // Add in the resolved_references of the used previous versions of the class
1216 // in the case of RedefineClasses
1217 InstanceKlass* prev = ik->previous_versions();
1218 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1219 field_count++;
1220 size += sizeof(address);
1221 prev = prev->previous_versions();
1222 }
1223 }
1224
1225 // We write the value itself plus a name and a one byte type tag per field.
1226 return checked_cast<u4>(size + field_count * (sizeof(address) + 1));
1227 }
1228
1229 // dumps static fields of the given class
1230 void DumperSupport::dump_static_fields(AbstractDumpWriter* writer, Klass* k) {
1231 InstanceKlass* ik = InstanceKlass::cast(k);
1232
1233 // dump the field descriptors and raw values
1234 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1235 if (fld.access_flags().is_static()) {
1236 assert(!is_inlined_field(fld.field_descriptor()), "static fields cannot be inlined");
1237
1238 Symbol* sig = fld.signature();
1239
1240 writer->write_symbolID(fld.name()); // name
1241 writer->write_u1(sig2tag(sig)); // type
1242
1243 // value
1244 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1245 }
1246 }
1247
1248 // Add resolved_references for each class that has them
1249 oop resolved_references = ik->constants()->resolved_references_or_null();
1250 if (resolved_references != nullptr) {
1251 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1252 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1253 writer->write_objectID(resolved_references);
1254
1255 // Also write any previous versions
1256 InstanceKlass* prev = ik->previous_versions();
1257 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1258 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1259 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1260 writer->write_objectID(prev->constants()->resolved_references());
1261 prev = prev->previous_versions();
1262 }
1263 }
1264 }
1265
1266 // dump the raw values of the instance fields of the given identity or inlined object;
1267 // for identity objects offset is 0 and 'klass' is o->klass(),
1268 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class.
1269 void DumperSupport::dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1270 assert(class_cache_entry != nullptr, "Pre-condition: must be provided");
1271 for (int idx = 0; idx < class_cache_entry->field_count(); idx++) {
1272 if (class_cache_entry->is_inlined(idx)) {
1273 InlineKlass* field_klass = class_cache_entry->inline_klass(idx);
1274 int fields_offset = offset + (class_cache_entry->offset(idx) - field_klass->first_field_offset());
1275 DumperClassCacheTableEntry* inline_class_cache_entry = class_cache->lookup_or_create(field_klass);
1276 dump_inlined_object_fields(writer, o, fields_offset, class_cache, inline_class_cache_entry);
1277 } else {
1278 dump_field_value(writer, class_cache_entry->sig_start(idx), o, class_cache_entry->offset(idx));
1279 }
1280 }
1281 }
1282
1283 void DumperSupport::dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1284 // the object is inlined, so all its fields are stored without headers.
1285 dump_instance_fields(writer, o, offset, class_cache, class_cache_entry);
1286 }
1287
1288 // gets the count of the instance fields for a given class
1289 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1290 u2 field_count = 0;
1291
1292 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1293 if (!fldc.access_flags().is_static()) {
1294 if (is_inlined_field(fldc.field_descriptor())) {
1295 // add "synthetic" fields for inlined fields.
1296 field_count += get_instance_fields_count(get_inlined_field_klass(fldc.field_descriptor()));
1297 } else {
1298 field_count++;
1299 }
1300 }
1301 }
1302
1303 return field_count;
1304 }
1305
1306 // dumps the definition of the instance fields for a given class
1307 // inlined_fields_id is not-nullptr for inlined fields (to get synthetic field name IDs
1308 // by using InlinedObjects::get_next_string_id()).
1309 void DumperSupport::dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* ik, uintx* inlined_fields_id) {
1310 // inlined_fields_id != nullptr means ik is a class of inlined field.
1311 // Inlined field id pointer for this class; lazyly initialized
1312 // if the class has inlined field(s) and the caller didn't provide inlined_fields_id.
1313 uintx *this_klass_inlined_fields_id = inlined_fields_id;
1314 uintx inlined_id = 0;
1315
1316 // dump the field descriptors
1317 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1318 if (!fld.access_flags().is_static()) {
1319 if (is_inlined_field(fld.field_descriptor())) {
1320 // dump "synthetic" fields for inlined fields.
1321 if (this_klass_inlined_fields_id == nullptr) {
1322 inlined_id = InlinedObjects::get_instance()->get_base_index_for(ik);
1323 this_klass_inlined_fields_id = &inlined_id;
1324 }
1325 dump_instance_field_descriptors(writer, get_inlined_field_klass(fld.field_descriptor()), this_klass_inlined_fields_id);
1326 } else {
1327 Symbol* sig = fld.signature();
1328 Symbol* name = nullptr;
1329 // Use inlined_fields_id provided by caller.
1330 if (inlined_fields_id != nullptr) {
1331 uintx name_id = InlinedObjects::get_instance()->get_next_string_id(*inlined_fields_id);
1332
1333 // name_id == 0 is returned on error. use original field signature.
1334 if (name_id != 0) {
1335 *inlined_fields_id = name_id;
1336 name = reinterpret_cast<Symbol*>(name_id);
1337 }
1338 }
1339 if (name == nullptr) {
1340 name = fld.name();
1341 }
1342
1343 writer->write_symbolID(name); // name
1344 writer->write_u1(sig2tag(sig)); // type
1345 }
1346 }
1347 }
1348 }
1349
1350 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1351 void DumperSupport::dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache) {
1352 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1353
1354 DumperClassCacheTableEntry* cache_entry = class_cache->lookup_or_create(ik);
1355
1356 u4 is = instance_size(ik, cache_entry);
1357 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1358
1359 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1360 writer->write_objectID(o);
1361 writer->write_u4(STACK_TRACE_ID);
1362
1363 // class ID
1364 writer->write_classID(ik);
1365
1366 // number of bytes that follow
1367 writer->write_u4(is);
1368
1369 // field values
1370 dump_instance_fields(writer, o, 0, class_cache, cache_entry);
1371
1372 writer->end_sub_record();
1373 }
1374
1375 // creates HPROF_GC_CLASS_DUMP record for the given instance class
1376 void DumperSupport::dump_instance_class(AbstractDumpWriter* writer, Klass* k) {
1377 InstanceKlass* ik = InstanceKlass::cast(k);
1378
1379 // We can safepoint and do a heap dump at a point where we have a Klass,
1380 // but no java mirror class has been setup for it. So we need to check
1381 // that the class is at least loaded, to avoid crash from a null mirror.
1382 if (!ik->is_loaded()) {
1383 return;
1384 }
1385
1386 u2 static_fields_count = 0;
1387 u4 static_size = get_static_fields_size(ik, static_fields_count);
1388 u2 instance_fields_count = get_instance_fields_count(ik);
1389 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1390 u4 size = checked_cast<u4>(1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size);
1391
1392 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1393
1394 // class ID
1395 writer->write_classID(ik);
1396 writer->write_u4(STACK_TRACE_ID);
1397
1398 // super class ID
1399 InstanceKlass* java_super = ik->java_super();
1400 if (java_super == nullptr) {
1401 writer->write_objectID(oop(nullptr));
1402 } else {
1403 writer->write_classID(java_super);
1404 }
1405
1406 writer->write_objectID(ik->class_loader());
1407 writer->write_objectID(ik->signers());
1408 writer->write_objectID(ik->protection_domain());
1409
1410 // reserved
1411 writer->write_objectID(oop(nullptr));
1412 writer->write_objectID(oop(nullptr));
1413
1414 // instance size
1415 writer->write_u4(HeapWordSize * ik->size_helper());
1416
1417 // size of constant pool - ignored by HAT 1.1
1418 writer->write_u2(0);
1419
1420 // static fields
1421 writer->write_u2(static_fields_count);
1422 dump_static_fields(writer, ik);
1423
1424 // description of instance fields
1425 writer->write_u2(instance_fields_count);
1426 dump_instance_field_descriptors(writer, ik);
1427
1428 writer->end_sub_record();
1429 }
1430
1431 // creates HPROF_GC_CLASS_DUMP record for the given array class
1432 void DumperSupport::dump_array_class(AbstractDumpWriter* writer, Klass* k) {
1433 InstanceKlass* ik = nullptr; // bottom class for object arrays, null for primitive type arrays
1434 if (k->is_objArray_klass()) {
1435 Klass *bk = ObjArrayKlass::cast(k)->bottom_klass();
1436 assert(bk != nullptr, "checking");
1437 if (bk->is_instance_klass()) {
1438 ik = InstanceKlass::cast(bk);
1439 }
1440 }
1441
1442 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1443 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1444 writer->write_classID(k);
1445 writer->write_u4(STACK_TRACE_ID);
1446
1447 // super class of array classes is java.lang.Object
1448 InstanceKlass* java_super = k->java_super();
1449 assert(java_super != nullptr, "checking");
1450 writer->write_classID(java_super);
1451
1452 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->class_loader());
1453 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->signers());
1454 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->protection_domain());
1455
1456 writer->write_objectID(oop(nullptr)); // reserved
1457 writer->write_objectID(oop(nullptr));
1458 writer->write_u4(0); // instance size
1459 writer->write_u2(0); // constant pool
1460 writer->write_u2(0); // static fields
1461 writer->write_u2(0); // instance fields
1462
1463 writer->end_sub_record();
1464
1465 }
1466
1467 // Hprof uses an u4 as record length field,
1468 // which means we need to truncate arrays that are too long.
1469 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size) {
1470 int length = array->length();
1471
1472 size_t length_in_bytes = (size_t)length * type_size;
1473 uint max_bytes = max_juint - header_size;
1474
1475 if (length_in_bytes > max_bytes) {
1476 length = max_bytes / type_size;
1477 length_in_bytes = (size_t)length * type_size;
1478
1479 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1480 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1481 type2name_tab[type], array->length(), length);
1482 }
1483 return length;
1484 }
1485
1486 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size) {
1487 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1488 assert((type >= T_BOOLEAN && type <= T_OBJECT) || type == T_PRIMITIVE_OBJECT, "invalid array element type");
1489 int type_size;
1490 if (type == T_OBJECT) {
1491 type_size = sizeof(address);
1492 } else if (type == T_PRIMITIVE_OBJECT) {
1493 // TODO: FIXME
1494 fatal("Not supported yet"); // FIXME: JDK-8325678
1495 } else {
1496 type_size = type2aelembytes(type);
1497 }
1498
1499 return calculate_array_max_length(writer, array, type_size, header_size);
1500 }
1501
1502 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1503 void DumperSupport::dump_object_array(AbstractDumpWriter* writer, objArrayOop array) {
1504 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1505 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1506 int length = calculate_array_max_length(writer, array, header_size);
1507 u4 size = checked_cast<u4>(header_size + length * sizeof(address));
1508
1509 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1510 writer->write_objectID(array);
1511 writer->write_u4(STACK_TRACE_ID);
1512 writer->write_u4(length);
1513
1514 // array class ID
1515 writer->write_classID(array->klass());
1516
1517 // [id]* elements
1518 for (int index = 0; index < length; index++) {
1519 oop o = array->obj_at(index);
1520 o = mask_dormant_archived_object(o, array);
1521 writer->write_objectID(o);
1522 }
1523
1524 writer->end_sub_record();
1525 }
1526
1527 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
1528 void DumperSupport::dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache) {
1529 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1530 InlineKlass* element_klass = array_klass->element_klass();
1531 int element_size = instance_size(element_klass);
1532 /* id array object ID
1533 * u4 stack trace serial number
1534 * u4 number of elements
1535 * u1 element type
1536 */
1537 short header_size = 1 + sizeof(address) + 2 * 4 + 1;
1538
1539 // TODO: use T_SHORT/T_INT/T_LONG if needed to avoid truncation
1540 BasicType type = T_BYTE;
1541 int type_size = type2aelembytes(type);
1542 int length = calculate_array_max_length(writer, array, element_size, header_size);
1543 u4 length_in_bytes = (u4)(length * element_size);
1544 u4 size = header_size + length_in_bytes;
1545
1546 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1547 writer->write_objectID(array);
1548 writer->write_u4(STACK_TRACE_ID);
1549 // TODO: round up array length for T_SHORT/T_INT/T_LONG
1550 writer->write_u4(length * element_size);
1551 writer->write_u1(type2tag(type));
1552
1553 for (int index = 0; index < length; index++) {
1554 // need offset in the holder to read inlined object. calculate it from flatArrayOop::value_at_addr()
1555 int offset = (int)((address)array->value_at_addr(index, array_klass->layout_helper())
1556 - cast_from_oop<address>(array));
1557 DumperClassCacheTableEntry* class_cache_entry = class_cache->lookup_or_create(element_klass);
1558 dump_inlined_object_fields(writer, array, offset, class_cache, class_cache_entry);
1559 }
1560
1561 // TODO: write padding bytes for T_SHORT/T_INT/T_LONG
1562
1563 InlinedObjects::get_instance()->add_flat_array(array);
1564
1565 writer->end_sub_record();
1566 }
1567
1568 #define WRITE_ARRAY(Array, Type, Size, Length) \
1569 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1570
1571 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1572 void DumperSupport::dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array) {
1573 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1574 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1575 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1576
1577 int length = calculate_array_max_length(writer, array, header_size);
1578 int type_size = type2aelembytes(type);
1579 u4 length_in_bytes = (u4)length * type_size;
1580 u4 size = header_size + length_in_bytes;
1581
1582 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1583 writer->write_objectID(array);
1584 writer->write_u4(STACK_TRACE_ID);
1585 writer->write_u4(length);
1586 writer->write_u1(type2tag(type));
1587
1588 // nothing to copy
1589 if (length == 0) {
1590 writer->end_sub_record();
1591 return;
1592 }
1593
1594 // If the byte ordering is big endian then we can copy most types directly
1595
1596 switch (type) {
1597 case T_INT : {
1598 if (Endian::is_Java_byte_ordering_different()) {
1599 WRITE_ARRAY(array, int, u4, length);
1600 } else {
1601 writer->write_raw(array->int_at_addr(0), length_in_bytes);
1602 }
1603 break;
1604 }
1605 case T_BYTE : {
1606 writer->write_raw(array->byte_at_addr(0), length_in_bytes);
1607 break;
1608 }
1609 case T_CHAR : {
1610 if (Endian::is_Java_byte_ordering_different()) {
1611 WRITE_ARRAY(array, char, u2, length);
1612 } else {
1613 writer->write_raw(array->char_at_addr(0), length_in_bytes);
1614 }
1615 break;
1616 }
1617 case T_SHORT : {
1618 if (Endian::is_Java_byte_ordering_different()) {
1619 WRITE_ARRAY(array, short, u2, length);
1620 } else {
1621 writer->write_raw(array->short_at_addr(0), length_in_bytes);
1622 }
1623 break;
1624 }
1625 case T_BOOLEAN : {
1626 if (Endian::is_Java_byte_ordering_different()) {
1627 WRITE_ARRAY(array, bool, u1, length);
1628 } else {
1629 writer->write_raw(array->bool_at_addr(0), length_in_bytes);
1630 }
1631 break;
1632 }
1633 case T_LONG : {
1634 if (Endian::is_Java_byte_ordering_different()) {
1635 WRITE_ARRAY(array, long, u8, length);
1636 } else {
1637 writer->write_raw(array->long_at_addr(0), length_in_bytes);
1638 }
1639 break;
1640 }
1641
1642 // handle float/doubles in a special value to ensure than NaNs are
1643 // written correctly. TO DO: Check if we can avoid this on processors that
1644 // use IEEE 754.
1645
1646 case T_FLOAT : {
1647 for (int i = 0; i < length; i++) {
1648 dump_float(writer, array->float_at(i));
1649 }
1650 break;
1651 }
1652 case T_DOUBLE : {
1653 for (int i = 0; i < length; i++) {
1654 dump_double(writer, array->double_at(i));
1655 }
1656 break;
1657 }
1658 default : ShouldNotReachHere();
1659 }
1660
1661 writer->end_sub_record();
1662 }
1663
1664 // create a HPROF_FRAME record of the given Method* and bci
1665 void DumperSupport::dump_stack_frame(AbstractDumpWriter* writer,
1666 int frame_serial_num,
1667 int class_serial_num,
1668 Method* m,
1669 int bci) {
1670 int line_number;
1671 if (m->is_native()) {
1672 line_number = -3; // native frame
1673 } else {
1674 line_number = m->line_number_from_bci(bci);
1675 }
1676
1677 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1678 writer->write_id(frame_serial_num); // frame serial number
1679 writer->write_symbolID(m->name()); // method's name
1680 writer->write_symbolID(m->signature()); // method's signature
1681
1682 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1683 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1684 writer->write_u4(class_serial_num); // class serial number
1685 writer->write_u4((u4) line_number); // line number
1686 }
1687
1688
1689 class InlinedFieldNameDumper : public LockedClassesDo {
1690 public:
1691 typedef void (*Callback)(InlinedObjects *owner, const Klass *klass, uintx base_index, int count);
1692
1693 private:
1694 AbstractDumpWriter* _writer;
1695 InlinedObjects *_owner;
1696 Callback _callback;
1697 uintx _index;
1698
1699 void dump_inlined_field_names(GrowableArray<Symbol*>* super_names, Symbol* field_name, InlineKlass* klass) {
1700 super_names->push(field_name);
1701 for (HierarchicalFieldStream<JavaFieldStream> fld(klass); !fld.done(); fld.next()) {
1702 if (!fld.access_flags().is_static()) {
1703 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1704 dump_inlined_field_names(super_names, fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1705 } else {
1706 // get next string ID.
1707 uintx next_index = _owner->get_next_string_id(_index);
1708 if (next_index == 0) {
1709 // something went wrong (overflow?)
1710 // stop generation; the rest of inlined objects will have original field names.
1711 return;
1712 }
1713 _index = next_index;
1714
1715 // Calculate length.
1716 int len = fld.name()->utf8_length();
1717 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1718 len += (*it)->utf8_length() + 1; // +1 for ".".
1719 }
1720
1721 DumperSupport::write_header(_writer, HPROF_UTF8, oopSize + len);
1722 _writer->write_symbolID(reinterpret_cast<Symbol*>(_index));
1723 // Write the string value.
1724 // 1) super_names.
1725 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1726 _writer->write_raw((*it)->bytes(), (*it)->utf8_length());
1727 _writer->write_u1('.');
1728 }
1729 // 2) field name.
1730 _writer->write_raw(fld.name()->bytes(), fld.name()->utf8_length());
1731 }
1732 }
1733 }
1734 super_names->pop();
1735 }
1736
1737 void dump_inlined_field_names(Symbol* field_name, InlineKlass* field_klass) {
1738 GrowableArray<Symbol*> super_names(4, mtServiceability);
1739 dump_inlined_field_names(&super_names, field_name, field_klass);
1740 }
1741
1742 public:
1743 InlinedFieldNameDumper(AbstractDumpWriter* writer, InlinedObjects* owner, Callback callback)
1744 : _writer(writer), _owner(owner), _callback(callback), _index(0) {
1745 }
1746
1747 void do_klass(Klass* k) {
1748 if (!k->is_instance_klass()) {
1749 return;
1750 }
1751 InstanceKlass* ik = InstanceKlass::cast(k);
1752 // if (ik->has_inline_type_fields()) {
1753 // return;
1754 // }
1755
1756 uintx base_index = _index;
1757 int count = 0;
1758
1759 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1760 if (!fld.access_flags().is_static()) {
1761 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1762 dump_inlined_field_names(fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1763 count++;
1764 }
1765 }
1766 }
1767
1768 if (count != 0) {
1769 _callback(_owner, k, base_index, count);
1770 }
1771 }
1772 };
1773
1774 class InlinedFieldsDumper : public LockedClassesDo {
1775 private:
1776 AbstractDumpWriter* _writer;
1777
1778 public:
1779 InlinedFieldsDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1780
1781 void do_klass(Klass* k) {
1782 if (!k->is_instance_klass()) {
1783 return;
1784 }
1785 InstanceKlass* ik = InstanceKlass::cast(k);
1786 // if (ik->has_inline_type_fields()) {
1787 // return;
1788 // }
1789
1790 // We can be at a point where java mirror does not exist yet.
1791 // So we need to check that the class is at least loaded, to avoid crash from a null mirror.
1792 if (!ik->is_loaded()) {
1793 return;
1794 }
1795
1796 u2 inlined_count = 0;
1797 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1798 if (!fld.access_flags().is_static()) {
1799 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1800 inlined_count++;
1801 }
1802 }
1803 }
1804 if (inlined_count != 0) {
1805 _writer->write_u1(HPROF_CLASS_WITH_INLINED_FIELDS);
1806
1807 // class ID
1808 _writer->write_classID(ik);
1809 // number of inlined fields
1810 _writer->write_u2(inlined_count);
1811 u2 index = 0;
1812 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1813 if (!fld.access_flags().is_static()) {
1814 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1815 // inlined field index
1816 _writer->write_u2(index);
1817 // synthetic field count
1818 u2 field_count = DumperSupport::get_instance_fields_count(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1819 _writer->write_u2(field_count);
1820 // original field name
1821 _writer->write_symbolID(fld.name());
1822 // inlined field class ID
1823 _writer->write_classID(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1824
1825 index += field_count;
1826 } else {
1827 index++;
1828 }
1829 }
1830 }
1831 }
1832 }
1833 };
1834
1835
1836 void InlinedObjects::init() {
1837 _instance = this;
1838
1839 struct Closure : public SymbolClosure {
1840 uintx _min_id = max_uintx;
1841 uintx _max_id = 0;
1842 Closure() : _min_id(max_uintx), _max_id(0) {}
1843
1844 void do_symbol(Symbol** p) {
1845 uintx val = reinterpret_cast<uintx>(*p);
1846 if (val < _min_id) {
1847 _min_id = val;
1848 }
1849 if (val > _max_id) {
1850 _max_id = val;
1851 }
1852 }
1853 } closure;
1854
1855 SymbolTable::symbols_do(&closure);
1856
1857 _min_string_id = closure._min_id;
1858 _max_string_id = closure._max_id;
1859 }
1860
1861 void InlinedObjects::release() {
1862 _instance = nullptr;
1863
1864 if (_inlined_field_map != nullptr) {
1865 delete _inlined_field_map;
1866 _inlined_field_map = nullptr;
1867 }
1868 if (_flat_arrays != nullptr) {
1869 delete _flat_arrays;
1870 _flat_arrays = nullptr;
1871 }
1872 }
1873
1874 void InlinedObjects::inlined_field_names_callback(InlinedObjects* _this, const Klass* klass, uintx base_index, int count) {
1875 if (_this->_inlined_field_map == nullptr) {
1876 _this->_inlined_field_map = new (mtServiceability) GrowableArray<ClassInlinedFields>(100, mtServiceability);
1877 }
1878 _this->_inlined_field_map->append(ClassInlinedFields(klass, base_index));
1879
1880 // counters for dumping classes with inlined fields
1881 _this->_classes_count++;
1882 _this->_inlined_fields_count += count;
1883 }
1884
1885 void InlinedObjects::dump_inlined_field_names(AbstractDumpWriter* writer) {
1886 InlinedFieldNameDumper nameDumper(writer, this, inlined_field_names_callback);
1887 ClassLoaderDataGraph::classes_do(&nameDumper);
1888
1889 if (_inlined_field_map != nullptr) {
1890 // prepare the map for get_base_index_for().
1891 _inlined_field_map->sort(ClassInlinedFields::compare);
1892 }
1893 }
1894
1895 uintx InlinedObjects::get_base_index_for(Klass* k) {
1896 if (_inlined_field_map != nullptr) {
1897 bool found = false;
1898 int idx = _inlined_field_map->find_sorted<ClassInlinedFields, ClassInlinedFields::compare>(ClassInlinedFields(k, 0), found);
1899 if (found) {
1900 return _inlined_field_map->at(idx).base_index;
1901 }
1902 }
1903
1904 // return max_uintx, so get_next_string_id returns 0.
1905 return max_uintx;
1906 }
1907
1908 uintx InlinedObjects::get_next_string_id(uintx id) {
1909 if (++id == _min_string_id) {
1910 return _max_string_id + 1;
1911 }
1912 return id;
1913 }
1914
1915 void InlinedObjects::dump_classed_with_inlined_fields(AbstractDumpWriter* writer) {
1916 if (_classes_count != 0) {
1917 // Record for each class contains tag(u1), class ID and count(u2)
1918 // for each inlined field index(u2), synthetic fields count(u2), original field name and class ID
1919 int size = _classes_count * (1 + sizeof(address) + 2)
1920 + _inlined_fields_count * (2 + 2 + sizeof(address) + sizeof(address));
1921 DumperSupport::write_header(writer, HPROF_INLINED_FIELDS, (u4)size);
1922
1923 InlinedFieldsDumper dumper(writer);
1924 ClassLoaderDataGraph::classes_do(&dumper);
1925 }
1926 }
1927
1928 void InlinedObjects::add_flat_array(oop array) {
1929 if (_flat_arrays == nullptr) {
1930 _flat_arrays = new (mtServiceability) GrowableArray<oop>(100, mtServiceability);
1931 }
1932 _flat_arrays->append(array);
1933 }
1934
1935 void InlinedObjects::dump_flat_arrays(AbstractDumpWriter* writer) {
1936 if (_flat_arrays != nullptr) {
1937 // For each flat array the record contains tag (u1), object ID and class ID.
1938 int size = _flat_arrays->length() * (1 + sizeof(address) + sizeof(address));
1939
1940 DumperSupport::write_header(writer, HPROF_FLAT_ARRAYS, (u4)size);
1941 for (GrowableArrayIterator<oop> it = _flat_arrays->begin(); it != _flat_arrays->end(); ++it) {
1942 flatArrayOop array = flatArrayOop(*it);
1943 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1944 InlineKlass* element_klass = array_klass->element_klass();
1945 writer->write_u1(HPROF_FLAT_ARRAY);
1946 writer->write_objectID(array);
1947 writer->write_classID(element_klass);
1948 }
1949 }
1950 }
1951
1952
1953 // Support class used to generate HPROF_UTF8 records from the entries in the
1954 // SymbolTable.
1955
1956 class SymbolTableDumper : public SymbolClosure {
1957 private:
1958 AbstractDumpWriter* _writer;
1959 AbstractDumpWriter* writer() const { return _writer; }
1960 public:
1961 SymbolTableDumper(AbstractDumpWriter* writer) { _writer = writer; }
1962 void do_symbol(Symbol** p);
1963 };
1964
1965 void SymbolTableDumper::do_symbol(Symbol** p) {
1966 ResourceMark rm;
1967 Symbol* sym = *p;
1968 int len = sym->utf8_length();
1969 if (len > 0) {
1970 char* s = sym->as_utf8();
1971 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1972 writer()->write_symbolID(sym);
1973 writer()->write_raw(s, len);
1974 }
1975 }
1976
1977 // Support class used to generate HPROF_GC_CLASS_DUMP records
1978
1979 class ClassDumper : public KlassClosure {
1980 private:
1981 AbstractDumpWriter* _writer;
1982 AbstractDumpWriter* writer() const { return _writer; }
1983
1984 public:
1985 ClassDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1986
1987 void do_klass(Klass* k) {
1988 if (k->is_instance_klass()) {
1989 DumperSupport::dump_instance_class(writer(), k);
1990 } else {
1991 DumperSupport::dump_array_class(writer(), k);
1992 }
1993 }
1994 };
1995
1996 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1997
1998 class JNILocalsDumper : public OopClosure {
1999 private:
2000 AbstractDumpWriter* _writer;
2001 u4 _thread_serial_num;
2002 int _frame_num;
2003 AbstractDumpWriter* writer() const { return _writer; }
2004 public:
2005 JNILocalsDumper(AbstractDumpWriter* writer, u4 thread_serial_num) {
2006 _writer = writer;
2007 _thread_serial_num = thread_serial_num;
2008 _frame_num = -1; // default - empty stack
2009 }
2010 void set_frame_number(int n) { _frame_num = n; }
2011 void do_oop(oop* obj_p);
2012 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2013 };
2014
2015 void JNILocalsDumper::do_oop(oop* obj_p) {
2016 // ignore null handles
2017 oop o = *obj_p;
2018 if (o != nullptr) {
2019 u4 size = 1 + sizeof(address) + 4 + 4;
2020 writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
2021 writer()->write_objectID(o);
2022 writer()->write_u4(_thread_serial_num);
2023 writer()->write_u4((u4)_frame_num);
2024 writer()->end_sub_record();
2025 }
2026 }
2027
2028
2029 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
2030
2031 class JNIGlobalsDumper : public OopClosure {
2032 private:
2033 AbstractDumpWriter* _writer;
2034 AbstractDumpWriter* writer() const { return _writer; }
2035
2036 public:
2037 JNIGlobalsDumper(AbstractDumpWriter* writer) {
2038 _writer = writer;
2039 }
2040 void do_oop(oop* obj_p);
2041 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2042 };
2043
2044 void JNIGlobalsDumper::do_oop(oop* obj_p) {
2045 oop o = NativeAccess<AS_NO_KEEPALIVE>::oop_load(obj_p);
2046
2047 // ignore these
2048 if (o == nullptr) return;
2049 // we ignore global ref to symbols and other internal objects
2050 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
2051 u4 size = 1 + 2 * sizeof(address);
2052 writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
2053 writer()->write_objectID(o);
2054 writer()->write_rootID(obj_p); // global ref ID
2055 writer()->end_sub_record();
2056 }
2057 };
2058
2059 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
2060
2061 class StickyClassDumper : public KlassClosure {
2062 private:
2063 AbstractDumpWriter* _writer;
2064 AbstractDumpWriter* writer() const { return _writer; }
2065 public:
2066 StickyClassDumper(AbstractDumpWriter* writer) {
2067 _writer = writer;
2068 }
2069 void do_klass(Klass* k) {
2070 if (k->is_instance_klass()) {
2071 InstanceKlass* ik = InstanceKlass::cast(k);
2072 u4 size = 1 + sizeof(address);
2073 writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
2074 writer()->write_classID(ik);
2075 writer()->end_sub_record();
2076 }
2077 }
2078 };
2079
2080 // Support class used to generate HPROF_GC_ROOT_JAVA_FRAME records.
2081
2082 class JavaStackRefDumper : public StackObj {
2083 private:
2084 AbstractDumpWriter* _writer;
2085 u4 _thread_serial_num;
2086 int _frame_num;
2087 AbstractDumpWriter* writer() const { return _writer; }
2088 public:
2089 JavaStackRefDumper(AbstractDumpWriter* writer, u4 thread_serial_num)
2090 : _writer(writer), _thread_serial_num(thread_serial_num), _frame_num(-1) // default - empty stack
2091 {
2092 }
2093
2094 void set_frame_number(int n) { _frame_num = n; }
2095
2096 void dump_java_stack_refs(StackValueCollection* values);
2097 };
2098
2099 void JavaStackRefDumper::dump_java_stack_refs(StackValueCollection* values) {
2100 for (int index = 0; index < values->size(); index++) {
2101 if (values->at(index)->type() == T_OBJECT) {
2102 oop o = values->obj_at(index)();
2103 if (o != nullptr) {
2104 u4 size = 1 + sizeof(address) + 4 + 4;
2105 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
2106 writer()->write_objectID(o);
2107 writer()->write_u4(_thread_serial_num);
2108 writer()->write_u4((u4)_frame_num);
2109 writer()->end_sub_record();
2110 }
2111 }
2112 }
2113 }
2114
2115 // Class to collect, store and dump thread-related data:
2116 // - HPROF_TRACE and HPROF_FRAME records;
2117 // - HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecords.
2118 class ThreadDumper : public CHeapObj<mtInternal> {
2119 public:
2120 enum class ThreadType { Platform, MountedVirtual, UnmountedVirtual };
2121
2122 private:
2123 ThreadType _thread_type;
2124 JavaThread* _java_thread;
2125 oop _thread_oop;
2126
2127 GrowableArray<StackFrameInfo*>* _frames;
2128 // non-null if the thread is OOM thread
2129 Method* _oome_constructor;
2130 int _thread_serial_num;
2131 int _start_frame_serial_num;
2132
2133 vframe* get_top_frame() const;
2134
2135 public:
2136 static bool should_dump_pthread(JavaThread* thread) {
2137 return thread->threadObj() != nullptr && !thread->is_exiting() && !thread->is_hidden_from_external_view();
2138 }
2139
2140 static bool should_dump_vthread(oop vt) {
2141 return java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::NEW
2142 && java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::TERMINATED;
2143 }
2144
2145 static bool is_vthread_mounted(oop vt) {
2146 // The code should be consistent with the "mounted virtual thread" case
2147 // (VM_HeapDumper::dump_stack_traces(), ThreadDumper::get_top_frame()).
2148 // I.e. virtual thread is mounted if its carrierThread is not null
2149 // and is_vthread_mounted() for the carrier thread returns true.
2150 oop carrier_thread = java_lang_VirtualThread::carrier_thread(vt);
2151 if (carrier_thread == nullptr) {
2152 return false;
2153 }
2154 JavaThread* java_thread = java_lang_Thread::thread(carrier_thread);
2155 return java_thread->is_vthread_mounted();
2156 }
2157
2158 ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop);
2159
2160 // affects frame_count
2161 void add_oom_frame(Method* oome_constructor) {
2162 assert(_start_frame_serial_num == 0, "add_oom_frame cannot be called after init_serial_nums");
2163 _oome_constructor = oome_constructor;
2164 }
2165
2166 void init_serial_nums(volatile int* thread_counter, volatile int* frame_counter) {
2167 assert(_start_frame_serial_num == 0, "already initialized");
2168 _thread_serial_num = Atomic::fetch_then_add(thread_counter, 1);
2169 _start_frame_serial_num = Atomic::fetch_then_add(frame_counter, frame_count());
2170 }
2171
2172 bool oom_thread() const {
2173 return _oome_constructor != nullptr;
2174 }
2175
2176 int frame_count() const {
2177 return _frames->length() + (oom_thread() ? 1 : 0);
2178 }
2179
2180 u4 thread_serial_num() const {
2181 return (u4)_thread_serial_num;
2182 }
2183
2184 u4 stack_trace_serial_num() const {
2185 return (u4)(_thread_serial_num + STACK_TRACE_ID);
2186 }
2187
2188 // writes HPROF_TRACE and HPROF_FRAME records
2189 // returns number of dumped frames
2190 void dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map);
2191
2192 // writes HPROF_GC_ROOT_THREAD_OBJ subrecord
2193 void dump_thread_obj(AbstractDumpWriter* writer);
2194
2195 // Walk the stack of the thread.
2196 // Dumps a HPROF_GC_ROOT_JAVA_FRAME subrecord for each local
2197 // Dumps a HPROF_GC_ROOT_JNI_LOCAL subrecord for each JNI local
2198 void dump_stack_refs(AbstractDumpWriter* writer);
2199
2200 };
2201
2202 ThreadDumper::ThreadDumper(ThreadType thread_type, JavaThread* java_thread, oop thread_oop)
2203 : _thread_type(thread_type), _java_thread(java_thread), _thread_oop(thread_oop),
2204 _oome_constructor(nullptr),
2205 _thread_serial_num(0), _start_frame_serial_num(0)
2206 {
2207 // sanity checks
2208 if (_thread_type == ThreadType::UnmountedVirtual) {
2209 assert(_java_thread == nullptr, "sanity");
2210 assert(_thread_oop != nullptr, "sanity");
2211 } else {
2212 assert(_java_thread != nullptr, "sanity");
2213 assert(_thread_oop != nullptr, "sanity");
2214 }
2215
2216 _frames = new (mtServiceability) GrowableArray<StackFrameInfo*>(10, mtServiceability);
2217 bool stop_at_vthread_entry = _thread_type == ThreadType::MountedVirtual;
2218
2219 // vframes are resource allocated
2220 Thread* current_thread = Thread::current();
2221 ResourceMark rm(current_thread);
2222 HandleMark hm(current_thread);
2223
2224 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2225 if (stop_at_vthread_entry && vf->is_vthread_entry()) {
2226 break;
2227 }
2228 if (vf->is_java_frame()) {
2229 javaVFrame* jvf = javaVFrame::cast(vf);
2230 _frames->append(new StackFrameInfo(jvf, false));
2231 } else {
2232 // ignore non-Java frames
2233 }
2234 }
2235 }
2236
2237 void ThreadDumper::dump_stack_traces(AbstractDumpWriter* writer, GrowableArray<Klass*>* klass_map) {
2238 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_nums are not initialized");
2239
2240 // write HPROF_FRAME records for this thread's stack trace
2241 int depth = _frames->length();
2242 int frame_serial_num = _start_frame_serial_num;
2243
2244 if (oom_thread()) {
2245 // OOM thread
2246 // write fake frame that makes it look like the thread, which caused OOME,
2247 // is in the OutOfMemoryError zero-parameter constructor
2248 int oome_serial_num = klass_map->find(_oome_constructor->method_holder());
2249 // the class serial number starts from 1
2250 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
2251 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, oome_serial_num, _oome_constructor, 0);
2252 depth++;
2253 }
2254
2255 for (int j = 0; j < _frames->length(); j++) {
2256 StackFrameInfo* frame = _frames->at(j);
2257 Method* m = frame->method();
2258 int class_serial_num = klass_map->find(m->method_holder());
2259 // the class serial number starts from 1
2260 assert(class_serial_num > 0, "class not found");
2261 DumperSupport::dump_stack_frame(writer, ++frame_serial_num, class_serial_num, m, frame->bci());
2262 }
2263
2264 // write HPROF_TRACE record for the thread
2265 DumperSupport::write_header(writer, HPROF_TRACE, checked_cast<u4>(3 * sizeof(u4) + depth * oopSize));
2266 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2267 writer->write_u4(thread_serial_num()); // thread serial number
2268 writer->write_u4((u4)depth); // frame count (including oom frame)
2269 for (int j = 1; j <= depth; j++) {
2270 writer->write_id(_start_frame_serial_num + j);
2271 }
2272 }
2273
2274 void ThreadDumper::dump_thread_obj(AbstractDumpWriter * writer) {
2275 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2276
2277 u4 size = 1 + sizeof(address) + 4 + 4;
2278 writer->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
2279 writer->write_objectID(_thread_oop);
2280 writer->write_u4(thread_serial_num()); // thread serial number
2281 writer->write_u4(stack_trace_serial_num()); // stack trace serial number
2282 writer->end_sub_record();
2283 }
2284
2285 void ThreadDumper::dump_stack_refs(AbstractDumpWriter * writer) {
2286 assert(_thread_serial_num != 0 && _start_frame_serial_num != 0, "serial_num is not initialized");
2287
2288 JNILocalsDumper blk(writer, thread_serial_num());
2289 if (_thread_type == ThreadType::Platform) {
2290 if (!_java_thread->has_last_Java_frame()) {
2291 // no last java frame but there may be JNI locals
2292 _java_thread->active_handles()->oops_do(&blk);
2293 return;
2294 }
2295 }
2296
2297 JavaStackRefDumper java_ref_dumper(writer, thread_serial_num());
2298
2299 // vframes are resource allocated
2300 Thread* current_thread = Thread::current();
2301 ResourceMark rm(current_thread);
2302 HandleMark hm(current_thread);
2303
2304 bool stopAtVthreadEntry = _thread_type == ThreadType::MountedVirtual;
2305 frame* last_entry_frame = nullptr;
2306 bool is_top_frame = true;
2307 int depth = 0;
2308 if (oom_thread()) {
2309 depth++;
2310 }
2311
2312 for (vframe* vf = get_top_frame(); vf != nullptr; vf = vf->sender()) {
2313 if (stopAtVthreadEntry && vf->is_vthread_entry()) {
2314 break;
2315 }
2316
2317 if (vf->is_java_frame()) {
2318 javaVFrame* jvf = javaVFrame::cast(vf);
2319 if (!(jvf->method()->is_native())) {
2320 java_ref_dumper.set_frame_number(depth);
2321 java_ref_dumper.dump_java_stack_refs(jvf->locals());
2322 java_ref_dumper.dump_java_stack_refs(jvf->expressions());
2323 } else {
2324 // native frame
2325 blk.set_frame_number(depth);
2326 if (is_top_frame) {
2327 // JNI locals for the top frame.
2328 assert(_java_thread != nullptr, "impossible for unmounted vthread");
2329 _java_thread->active_handles()->oops_do(&blk);
2330 } else {
2331 if (last_entry_frame != nullptr) {
2332 // JNI locals for the entry frame
2333 assert(last_entry_frame->is_entry_frame(), "checking");
2334 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
2335 }
2336 }
2337 }
2338 last_entry_frame = nullptr;
2339 // increment only for Java frames
2340 depth++;
2341 } else {
2342 // externalVFrame - for an entry frame then we report the JNI locals
2343 // when we find the corresponding javaVFrame
2344 frame* fr = vf->frame_pointer();
2345 assert(fr != nullptr, "sanity check");
2346 if (fr->is_entry_frame()) {
2347 last_entry_frame = fr;
2348 }
2349 }
2350 is_top_frame = false;
2351 }
2352 assert(depth == frame_count(), "total number of Java frames not matched");
2353 }
2354
2355 vframe* ThreadDumper::get_top_frame() const {
2356 if (_thread_type == ThreadType::UnmountedVirtual) {
2357 ContinuationWrapper cont(java_lang_VirtualThread::continuation(_thread_oop));
2358 if (cont.is_empty()) {
2359 return nullptr;
2360 }
2361 assert(!cont.is_mounted(), "sanity check");
2362 stackChunkOop chunk = cont.last_nonempty_chunk();
2363 if (chunk == nullptr || chunk->is_empty()) {
2364 return nullptr;
2365 }
2366
2367 RegisterMap reg_map(cont.continuation(), RegisterMap::UpdateMap::include);
2368 frame fr = chunk->top_frame(®_map);
2369 vframe* vf = vframe::new_vframe(&fr, ®_map, nullptr); // don't need JavaThread
2370 return vf;
2371 }
2372
2373 RegisterMap reg_map(_java_thread,
2374 RegisterMap::UpdateMap::include,
2375 RegisterMap::ProcessFrames::include,
2376 RegisterMap::WalkContinuation::skip);
2377 switch (_thread_type) {
2378 case ThreadType::Platform:
2379 if (!_java_thread->has_last_Java_frame()) {
2380 return nullptr;
2381 }
2382 return _java_thread->is_vthread_mounted()
2383 ? _java_thread->carrier_last_java_vframe(®_map)
2384 : _java_thread->platform_thread_last_java_vframe(®_map);
2385
2386 case ThreadType::MountedVirtual:
2387 return _java_thread->last_java_vframe(®_map);
2388
2389 default: // make compilers happy
2390 break;
2391 }
2392 ShouldNotReachHere();
2393 return nullptr;
2394 }
2395
2396 // Callback to dump thread-related data for unmounted virtual threads;
2397 // implemented by VM_HeapDumper.
2398 class UnmountedVThreadDumper {
2399 public:
2400 virtual void dump_vthread(oop vt, AbstractDumpWriter* segment_writer) = 0;
2401 };
2402
2403 // Support class used when iterating over the heap.
2404 class HeapObjectDumper : public ObjectClosure {
2405 private:
2406 AbstractDumpWriter* _writer;
2407 AbstractDumpWriter* writer() { return _writer; }
2408 UnmountedVThreadDumper* _vthread_dumper;
2409
2410 DumperClassCacheTable _class_cache;
2411
2412 public:
2413 HeapObjectDumper(AbstractDumpWriter* writer, UnmountedVThreadDumper* vthread_dumper)
2414 : _writer(writer), _vthread_dumper(vthread_dumper) {}
2415
2416 // called for each object in the heap
2417 void do_object(oop o);
2418 };
2419
2420 void HeapObjectDumper::do_object(oop o) {
2421 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
2422 if (o->klass() == vmClasses::Class_klass()) {
2423 if (!java_lang_Class::is_primitive(o)) {
2424 return;
2425 }
2426 }
2427
2428 if (DumperSupport::mask_dormant_archived_object(o, nullptr) == nullptr) {
2429 return;
2430 }
2431
2432 if (o->is_instance()) {
2433 // create a HPROF_GC_INSTANCE record for each object
2434 DumperSupport::dump_instance(writer(), o, &_class_cache);
2435 // If we encounter an unmounted virtual thread it needs to be dumped explicitly
2436 // (mounted virtual threads are dumped with their carriers).
2437 if (java_lang_VirtualThread::is_instance(o)
2438 && ThreadDumper::should_dump_vthread(o) && !ThreadDumper::is_vthread_mounted(o)) {
2439 _vthread_dumper->dump_vthread(o, writer());
2440 }
2441 } else if (o->is_objArray()) {
2442 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
2443 DumperSupport::dump_object_array(writer(), objArrayOop(o));
2444 } else if (o->is_flatArray()) {
2445 DumperSupport::dump_flat_array(writer(), flatArrayOop(o), &_class_cache);
2446 } else if (o->is_typeArray()) {
2447 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
2448 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
2449 }
2450 }
2451
2452 // The dumper controller for parallel heap dump
2453 class DumperController : public CHeapObj<mtInternal> {
2454 private:
2455 Monitor* _lock;
2456 Mutex* _global_writer_lock;
2457
2458 const uint _dumper_number;
2459 uint _complete_number;
2460
2461 bool _started; // VM dumper started and acquired global writer lock
2462
2463 public:
2464 DumperController(uint number) :
2465 // _lock and _global_writer_lock are used for synchronization between GC worker threads inside safepoint,
2466 // so we lock with _no_safepoint_check_flag.
2467 // signal_start() acquires _lock when global writer is locked,
2468 // its rank must be less than _global_writer_lock rank.
2469 _lock(new (std::nothrow) PaddedMonitor(Mutex::nosafepoint - 1, "DumperController_lock")),
2470 _global_writer_lock(new (std::nothrow) Mutex(Mutex::nosafepoint, "DumpWriter_lock")),
2471 _dumper_number(number),
2472 _complete_number(0),
2473 _started(false)
2474 {}
2475
2476 ~DumperController() {
2477 delete _lock;
2478 delete _global_writer_lock;
2479 }
2480
2481 // parallel (non VM) dumpers must wait until VM dumper acquires global writer lock
2482 void wait_for_start_signal() {
2483 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2484 while (_started == false) {
2485 ml.wait();
2486 }
2487 }
2488
2489 void signal_start() {
2490 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2491 _started = true;
2492 ml.notify_all();
2493 }
2494
2495 void lock_global_writer() {
2496 _global_writer_lock->lock_without_safepoint_check();
2497 }
2498
2499 void unlock_global_writer() {
2500 _global_writer_lock->unlock();
2501 }
2502
2503 void dumper_complete(DumpWriter* local_writer, DumpWriter* global_writer) {
2504 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2505 _complete_number++;
2506 // propagate local error to global if any
2507 if (local_writer->has_error()) {
2508 global_writer->set_error(local_writer->error());
2509 }
2510 ml.notify();
2511 }
2512
2513 void wait_all_dumpers_complete() {
2514 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2515 while (_complete_number != _dumper_number) {
2516 ml.wait();
2517 }
2518 }
2519 };
2520
2521 // DumpMerger merges separate dump files into a complete one
2522 class DumpMerger : public StackObj {
2523 private:
2524 DumpWriter* _writer;
2525 InlinedObjects* _inlined_objects;
2526 const char* _path;
2527 bool _has_error;
2528 int _dump_seq;
2529
2530 private:
2531 void merge_file(const char* path);
2532 void merge_done();
2533 void set_error(const char* msg);
2534
2535 public:
2536 DumpMerger(const char* path, DumpWriter* writer, InlinedObjects* inlined_objects, int dump_seq) :
2537 _writer(writer),
2538 _inlined_objects(inlined_objects),
2539 _path(path),
2540 _has_error(_writer->has_error()),
2541 _dump_seq(dump_seq) {}
2542
2543 void do_merge();
2544
2545 // returns path for the parallel DumpWriter (resource allocated)
2546 static char* get_writer_path(const char* base_path, int seq);
2547
2548 };
2549
2550 char* DumpMerger::get_writer_path(const char* base_path, int seq) {
2551 // approximate required buffer size
2552 size_t buf_size = strlen(base_path)
2553 + 2 // ".p"
2554 + 10 // number (that's enough for 2^32 parallel dumpers)
2555 + 1; // '\0'
2556
2557 char* path = NEW_RESOURCE_ARRAY(char, buf_size);
2558 memset(path, 0, buf_size);
2559
2560 os::snprintf(path, buf_size, "%s.p%d", base_path, seq);
2561
2562 return path;
2563 }
2564
2565
2566 void DumpMerger::merge_done() {
2567 // Writes the HPROF_HEAP_DUMP_END record.
2568 if (!_has_error) {
2569 DumperSupport::end_of_dump(_writer);
2570 _inlined_objects->dump_flat_arrays(_writer);
2571 _writer->flush();
2572 _inlined_objects->release();
2573 }
2574 _dump_seq = 0; //reset
2575 }
2576
2577 void DumpMerger::set_error(const char* msg) {
2578 assert(msg != nullptr, "sanity check");
2579 log_error(heapdump)("%s (file: %s)", msg, _path);
2580 _writer->set_error(msg);
2581 _has_error = true;
2582 }
2583
2584 #ifdef LINUX
2585 // Merge segmented heap files via sendfile, it's more efficient than the
2586 // read+write combination, which would require transferring data to and from
2587 // user space.
2588 void DumpMerger::merge_file(const char* path) {
2589 TraceTime timer("Merge segmented heap file directly", TRACETIME_LOG(Info, heapdump));
2590
2591 int segment_fd = os::open(path, O_RDONLY, 0);
2592 if (segment_fd == -1) {
2593 set_error("Can not open segmented heap file during merging");
2594 return;
2595 }
2596
2597 struct stat st;
2598 if (os::stat(path, &st) != 0) {
2599 ::close(segment_fd);
2600 set_error("Can not get segmented heap file size during merging");
2601 return;
2602 }
2603
2604 // A successful call to sendfile may write fewer bytes than requested; the
2605 // caller should be prepared to retry the call if there were unsent bytes.
2606 jlong offset = 0;
2607 while (offset < st.st_size) {
2608 int ret = os::Linux::sendfile(_writer->get_fd(), segment_fd, &offset, st.st_size);
2609 if (ret == -1) {
2610 ::close(segment_fd);
2611 set_error("Failed to merge segmented heap file");
2612 return;
2613 }
2614 }
2615
2616 // As sendfile variant does not call the write method of the global writer,
2617 // bytes_written is also incorrect for this variant, we need to explicitly
2618 // accumulate bytes_written for the global writer in this case
2619 julong accum = _writer->bytes_written() + st.st_size;
2620 _writer->set_bytes_written(accum);
2621 ::close(segment_fd);
2622 }
2623 #else
2624 // Generic implementation using read+write
2625 void DumpMerger::merge_file(const char* path) {
2626 TraceTime timer("Merge segmented heap file", TRACETIME_LOG(Info, heapdump));
2627
2628 fileStream segment_fs(path, "rb");
2629 if (!segment_fs.is_open()) {
2630 set_error("Can not open segmented heap file during merging");
2631 return;
2632 }
2633
2634 jlong total = 0;
2635 size_t cnt = 0;
2636 char read_buf[4096];
2637 while ((cnt = segment_fs.read(read_buf, 1, 4096)) != 0) {
2638 _writer->write_raw(read_buf, cnt);
2639 total += cnt;
2640 }
2641
2642 _writer->flush();
2643 if (segment_fs.fileSize() != total) {
2644 set_error("Merged heap dump is incomplete");
2645 }
2646 }
2647 #endif
2648
2649 void DumpMerger::do_merge() {
2650 TraceTime timer("Merge heap files complete", TRACETIME_LOG(Info, heapdump));
2651
2652 // Since contents in segmented heap file were already zipped, we don't need to zip
2653 // them again during merging.
2654 AbstractCompressor* saved_compressor = _writer->compressor();
2655 _writer->set_compressor(nullptr);
2656
2657 // Merge the content of the remaining files into base file. Regardless of whether
2658 // the merge process is successful or not, these segmented files will be deleted.
2659 for (int i = 0; i < _dump_seq; i++) {
2660 ResourceMark rm;
2661 const char* path = get_writer_path(_path, i);
2662 if (!_has_error) {
2663 merge_file(path);
2664 }
2665 // Delete selected segmented heap file nevertheless
2666 if (remove(path) != 0) {
2667 log_info(heapdump)("Removal of segment file (%d) failed (%d)", i, errno);
2668 }
2669 }
2670
2671 // restore compressor for further use
2672 _writer->set_compressor(saved_compressor);
2673 merge_done();
2674 }
2675
2676 // The VM operation wraps DumpMerger so that it could be performed by VM thread
2677 class VM_HeapDumpMerge : public VM_Operation {
2678 private:
2679 DumpMerger* _merger;
2680 public:
2681 VM_HeapDumpMerge(DumpMerger* merger) : _merger(merger) {}
2682 VMOp_Type type() const { return VMOp_HeapDumpMerge; }
2683 // heap dump merge could happen outside safepoint
2684 virtual bool evaluate_at_safepoint() const { return false; }
2685 void doit() {
2686 _merger->do_merge();
2687 }
2688 };
2689
2690 // The VM operation that performs the heap dump
2691 class VM_HeapDumper : public VM_GC_Operation, public WorkerTask, public UnmountedVThreadDumper {
2692 private:
2693 static VM_HeapDumper* _global_dumper;
2694 static DumpWriter* _global_writer;
2695 DumpWriter* _local_writer;
2696 JavaThread* _oome_thread;
2697 Method* _oome_constructor;
2698 bool _gc_before_heap_dump;
2699 GrowableArray<Klass*>* _klass_map;
2700
2701 ThreadDumper** _thread_dumpers; // platform, carrier and mounted virtual threads
2702 int _thread_dumpers_count;
2703 volatile int _thread_serial_num;
2704 volatile int _frame_serial_num;
2705
2706 volatile int _dump_seq;
2707
2708 // Inlined object support.
2709 InlinedObjects _inlined_objects;
2710
2711 // parallel heap dump support
2712 uint _num_dumper_threads;
2713 DumperController* _dumper_controller;
2714 ParallelObjectIterator* _poi;
2715
2716 // Dumper id of VMDumper thread.
2717 static const int VMDumperId = 0;
2718 // VM dumper dumps both heap and non-heap data, other dumpers dump heap-only data.
2719 static bool is_vm_dumper(int dumper_id) { return dumper_id == VMDumperId; }
2720 // the 1st dumper calling get_next_dumper_id becomes VM dumper
2721 int get_next_dumper_id() {
2722 return Atomic::fetch_then_add(&_dump_seq, 1);
2723 }
2724
2725 // accessors and setters
2726 static VM_HeapDumper* dumper() { assert(_global_dumper != nullptr, "Error"); return _global_dumper; }
2727 static DumpWriter* writer() { assert(_global_writer != nullptr, "Error"); return _global_writer; }
2728
2729 void set_global_dumper() {
2730 assert(_global_dumper == nullptr, "Error");
2731 _global_dumper = this;
2732 }
2733 void set_global_writer() {
2734 assert(_global_writer == nullptr, "Error");
2735 _global_writer = _local_writer;
2736 }
2737 void clear_global_dumper() { _global_dumper = nullptr; }
2738 void clear_global_writer() { _global_writer = nullptr; }
2739
2740 bool skip_operation() const;
2741
2742 // writes a HPROF_LOAD_CLASS record to global writer
2743 static void do_load_class(Klass* k);
2744
2745 // HPROF_GC_ROOT_THREAD_OBJ records for platform and mounted virtual threads
2746 void dump_threads(AbstractDumpWriter* writer);
2747
2748 void add_class_serial_number(Klass* k, int serial_num) {
2749 _klass_map->at_put_grow(serial_num, k);
2750 }
2751
2752 bool is_oom_thread(JavaThread* thread) const {
2753 return thread == _oome_thread && _oome_constructor != nullptr;
2754 }
2755
2756 // HPROF_TRACE and HPROF_FRAME records for platform and mounted virtual threads
2757 void dump_stack_traces(AbstractDumpWriter* writer);
2758
2759 public:
2760 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome, uint num_dump_threads) :
2761 VM_GC_Operation(0 /* total collections, dummy, ignored */,
2762 GCCause::_heap_dump /* GC Cause */,
2763 0 /* total full collections, dummy, ignored */,
2764 gc_before_heap_dump),
2765 WorkerTask("dump heap") {
2766 _local_writer = writer;
2767 _gc_before_heap_dump = gc_before_heap_dump;
2768 _klass_map = new (mtServiceability) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, mtServiceability);
2769
2770 _thread_dumpers = nullptr;
2771 _thread_dumpers_count = 0;
2772 _thread_serial_num = 1;
2773 _frame_serial_num = 1;
2774
2775 _dump_seq = VMDumperId;
2776 _num_dumper_threads = num_dump_threads;
2777 _dumper_controller = nullptr;
2778 _poi = nullptr;
2779 if (oome) {
2780 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
2781 // get OutOfMemoryError zero-parameter constructor
2782 InstanceKlass* oome_ik = vmClasses::OutOfMemoryError_klass();
2783 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
2784 vmSymbols::void_method_signature());
2785 // get thread throwing OOME when generating the heap dump at OOME
2786 _oome_thread = JavaThread::current();
2787 } else {
2788 _oome_thread = nullptr;
2789 _oome_constructor = nullptr;
2790 }
2791 }
2792
2793 ~VM_HeapDumper() {
2794 if (_thread_dumpers != nullptr) {
2795 for (int i = 0; i < _thread_dumpers_count; i++) {
2796 delete _thread_dumpers[i];
2797 }
2798 FREE_C_HEAP_ARRAY(ThreadDumper*, _thread_dumpers);
2799 }
2800
2801 if (_dumper_controller != nullptr) {
2802 delete _dumper_controller;
2803 _dumper_controller = nullptr;
2804 }
2805 delete _klass_map;
2806 }
2807 int dump_seq() { return _dump_seq; }
2808 bool is_parallel_dump() { return _num_dumper_threads > 1; }
2809 void prepare_parallel_dump(WorkerThreads* workers);
2810
2811 InlinedObjects* inlined_objects() { return &_inlined_objects; }
2812
2813 VMOp_Type type() const { return VMOp_HeapDumper; }
2814 virtual bool doit_prologue();
2815 void doit();
2816 void work(uint worker_id);
2817
2818 // UnmountedVThreadDumper implementation
2819 void dump_vthread(oop vt, AbstractDumpWriter* segment_writer);
2820 };
2821
2822 VM_HeapDumper* VM_HeapDumper::_global_dumper = nullptr;
2823 DumpWriter* VM_HeapDumper::_global_writer = nullptr;
2824
2825 bool VM_HeapDumper::skip_operation() const {
2826 return false;
2827 }
2828
2829 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2830 void DumperSupport::end_of_dump(AbstractDumpWriter* writer) {
2831 writer->finish_dump_segment();
2832
2833 writer->write_u1(HPROF_HEAP_DUMP_END);
2834 writer->write_u4(0);
2835 writer->write_u4(0);
2836 }
2837
2838 // writes a HPROF_LOAD_CLASS record for the class
2839 void VM_HeapDumper::do_load_class(Klass* k) {
2840 static u4 class_serial_num = 0;
2841
2842 // len of HPROF_LOAD_CLASS record
2843 u4 remaining = 2*oopSize + 2*sizeof(u4);
2844
2845 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
2846
2847 // class serial number is just a number
2848 writer()->write_u4(++class_serial_num);
2849
2850 // class ID
2851 writer()->write_classID(k);
2852
2853 // add the Klass* and class serial number pair
2854 dumper()->add_class_serial_number(k, class_serial_num);
2855
2856 writer()->write_u4(STACK_TRACE_ID);
2857
2858 // class name ID
2859 Symbol* name = k->name();
2860 writer()->write_symbolID(name);
2861 }
2862
2863 // Write a HPROF_GC_ROOT_THREAD_OBJ record for platform/carrier and mounted virtual threads.
2864 // Then walk the stack so that locals and JNI locals are dumped.
2865 void VM_HeapDumper::dump_threads(AbstractDumpWriter* writer) {
2866 for (int i = 0; i < _thread_dumpers_count; i++) {
2867 _thread_dumpers[i]->dump_thread_obj(writer);
2868 _thread_dumpers[i]->dump_stack_refs(writer);
2869 }
2870 }
2871
2872 bool VM_HeapDumper::doit_prologue() {
2873 if (_gc_before_heap_dump && UseZGC) {
2874 // ZGC cannot perform a synchronous GC cycle from within the VM thread.
2875 // So ZCollectedHeap::collect_as_vm_thread() is a noop. To respect the
2876 // _gc_before_heap_dump flag a synchronous GC cycle is performed from
2877 // the caller thread in the prologue.
2878 Universe::heap()->collect(GCCause::_heap_dump);
2879 }
2880 return VM_GC_Operation::doit_prologue();
2881 }
2882
2883 void VM_HeapDumper::prepare_parallel_dump(WorkerThreads* workers) {
2884 uint num_active_workers = workers != nullptr ? workers->active_workers() : 0;
2885 uint num_requested_dump_threads = _num_dumper_threads;
2886 // check if we can dump in parallel based on requested and active threads
2887 if (num_active_workers <= 1 || num_requested_dump_threads <= 1) {
2888 _num_dumper_threads = 1;
2889 } else {
2890 _num_dumper_threads = clamp(num_requested_dump_threads, 2U, num_active_workers);
2891 }
2892 _dumper_controller = new (std::nothrow) DumperController(_num_dumper_threads);
2893 bool can_parallel = _num_dumper_threads > 1;
2894 log_info(heapdump)("Requested dump threads %u, active dump threads %u, "
2895 "actual dump threads %u, parallelism %s",
2896 num_requested_dump_threads, num_active_workers,
2897 _num_dumper_threads, can_parallel ? "true" : "false");
2898 }
2899
2900 // The VM operation that dumps the heap. The dump consists of the following
2901 // records:
2902 //
2903 // HPROF_HEADER
2904 // [HPROF_UTF8]*
2905 // [HPROF_LOAD_CLASS]*
2906 // [[HPROF_FRAME]*|HPROF_TRACE]*
2907 // [HPROF_GC_CLASS_DUMP]*
2908 // [HPROF_HEAP_DUMP_SEGMENT]*
2909 // HPROF_HEAP_DUMP_END
2910 //
2911 // The HPROF_TRACE records represent the stack traces where the heap dump
2912 // is generated and a "dummy trace" record which does not include
2913 // any frames. The dummy trace record is used to be referenced as the
2914 // unknown object alloc site.
2915 //
2916 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
2917 // To allow the heap dump be generated in a single pass we remember the position
2918 // of the dump length and fix it up after all sub-records have been written.
2919 // To generate the sub-records we iterate over the heap, writing
2920 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
2921 // records as we go. Once that is done we write records for some of the GC
2922 // roots.
2923
2924 void VM_HeapDumper::doit() {
2925
2926 CollectedHeap* ch = Universe::heap();
2927
2928 ch->ensure_parsability(false); // must happen, even if collection does
2929 // not happen (e.g. due to GCLocker)
2930
2931 if (_gc_before_heap_dump) {
2932 if (GCLocker::is_active()) {
2933 warning("GC locker is held; pre-heapdump GC was skipped");
2934 } else {
2935 ch->collect_as_vm_thread(GCCause::_heap_dump);
2936 }
2937 }
2938
2939 // At this point we should be the only dumper active, so
2940 // the following should be safe.
2941 set_global_dumper();
2942 set_global_writer();
2943
2944 WorkerThreads* workers = ch->safepoint_workers();
2945 prepare_parallel_dump(workers);
2946
2947 if (!is_parallel_dump()) {
2948 work(VMDumperId);
2949 } else {
2950 ParallelObjectIterator poi(_num_dumper_threads);
2951 _poi = &poi;
2952 workers->run_task(this, _num_dumper_threads);
2953 _poi = nullptr;
2954 }
2955
2956 // Now we clear the global variables, so that a future dumper can run.
2957 clear_global_dumper();
2958 clear_global_writer();
2959 }
2960
2961 void VM_HeapDumper::work(uint worker_id) {
2962 // VM Dumper works on all non-heap data dumping and part of heap iteration.
2963 int dumper_id = get_next_dumper_id();
2964
2965 if (is_vm_dumper(dumper_id)) {
2966 // lock global writer, it will be unlocked after VM Dumper finishes with non-heap data
2967 _dumper_controller->lock_global_writer();
2968 _dumper_controller->signal_start();
2969 } else {
2970 _dumper_controller->wait_for_start_signal();
2971 }
2972
2973 if (is_vm_dumper(dumper_id)) {
2974 TraceTime timer("Dump non-objects", TRACETIME_LOG(Info, heapdump));
2975 // Write the file header - we always use 1.0.2
2976 const char* header = "JAVA PROFILE 1.0.2";
2977
2978 // header is few bytes long - no chance to overflow int
2979 writer()->write_raw(header, strlen(header) + 1); // NUL terminated
2980 writer()->write_u4(oopSize);
2981 // timestamp is current time in ms
2982 writer()->write_u8(os::javaTimeMillis());
2983 // HPROF_UTF8 records
2984 SymbolTableDumper sym_dumper(writer());
2985 SymbolTable::symbols_do(&sym_dumper);
2986
2987 // HPROF_UTF8 records for inlined field names.
2988 inlined_objects()->init();
2989 inlined_objects()->dump_inlined_field_names(writer());
2990
2991 // HPROF_INLINED_FIELDS
2992 inlined_objects()->dump_classed_with_inlined_fields(writer());
2993
2994 // write HPROF_LOAD_CLASS records
2995 {
2996 LockedClassesDo locked_load_classes(&do_load_class);
2997 ClassLoaderDataGraph::classes_do(&locked_load_classes);
2998 }
2999
3000 // write HPROF_FRAME and HPROF_TRACE records
3001 // this must be called after _klass_map is built when iterating the classes above.
3002 dump_stack_traces(writer());
3003
3004 // unlock global writer, so parallel dumpers can dump stack traces of unmounted virtual threads
3005 _dumper_controller->unlock_global_writer();
3006 }
3007
3008 // HPROF_HEAP_DUMP/HPROF_HEAP_DUMP_SEGMENT starts here
3009
3010 ResourceMark rm;
3011 // share global compressor, local DumpWriter is not responsible for its life cycle
3012 DumpWriter segment_writer(DumpMerger::get_writer_path(writer()->get_file_path(), dumper_id),
3013 writer()->is_overwrite(), writer()->compressor());
3014 if (!segment_writer.has_error()) {
3015 if (is_vm_dumper(dumper_id)) {
3016 // dump some non-heap subrecords to heap dump segment
3017 TraceTime timer("Dump non-objects (part 2)", TRACETIME_LOG(Info, heapdump));
3018 // Writes HPROF_GC_CLASS_DUMP records
3019 ClassDumper class_dumper(&segment_writer);
3020 ClassLoaderDataGraph::classes_do(&class_dumper);
3021
3022 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
3023 dump_threads(&segment_writer);
3024
3025 // HPROF_GC_ROOT_JNI_GLOBAL
3026 JNIGlobalsDumper jni_dumper(&segment_writer);
3027 JNIHandles::oops_do(&jni_dumper);
3028 // technically not jni roots, but global roots
3029 // for things like preallocated throwable backtraces
3030 Universe::vm_global()->oops_do(&jni_dumper);
3031 // HPROF_GC_ROOT_STICKY_CLASS
3032 // These should be classes in the null class loader data, and not all classes
3033 // if !ClassUnloading
3034 StickyClassDumper stiky_class_dumper(&segment_writer);
3035 ClassLoaderData::the_null_class_loader_data()->classes_do(&stiky_class_dumper);
3036 }
3037
3038 // Heap iteration.
3039 // writes HPROF_GC_INSTANCE_DUMP records.
3040 // After each sub-record is written check_segment_length will be invoked
3041 // to check if the current segment exceeds a threshold. If so, a new
3042 // segment is started.
3043 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
3044 // of the heap dump.
3045
3046 TraceTime timer(is_parallel_dump() ? "Dump heap objects in parallel" : "Dump heap objects", TRACETIME_LOG(Info, heapdump));
3047 HeapObjectDumper obj_dumper(&segment_writer, this);
3048 if (!is_parallel_dump()) {
3049 Universe::heap()->object_iterate(&obj_dumper);
3050 } else {
3051 // == Parallel dump
3052 _poi->object_iterate(&obj_dumper, worker_id);
3053 }
3054
3055 segment_writer.finish_dump_segment();
3056 segment_writer.flush();
3057 }
3058
3059 _dumper_controller->dumper_complete(&segment_writer, writer());
3060
3061 if (is_vm_dumper(dumper_id)) {
3062 _dumper_controller->wait_all_dumpers_complete();
3063
3064 // flush global writer
3065 writer()->flush();
3066
3067 // At this point, all fragments of the heapdump have been written to separate files.
3068 // We need to merge them into a complete heapdump and write HPROF_HEAP_DUMP_END at that time.
3069 }
3070 }
3071
3072 void VM_HeapDumper::dump_stack_traces(AbstractDumpWriter* writer) {
3073 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
3074 DumperSupport::write_header(writer, HPROF_TRACE, 3 * sizeof(u4));
3075 writer->write_u4((u4)STACK_TRACE_ID);
3076 writer->write_u4(0); // thread number
3077 writer->write_u4(0); // frame count
3078
3079 // max number if every platform thread is carrier with mounted virtual thread
3080 _thread_dumpers = NEW_C_HEAP_ARRAY(ThreadDumper*, Threads::number_of_threads() * 2, mtInternal);
3081
3082 for (JavaThreadIteratorWithHandle jtiwh; JavaThread * thread = jtiwh.next(); ) {
3083 if (ThreadDumper::should_dump_pthread(thread)) {
3084 bool add_oom_frame = is_oom_thread(thread);
3085
3086 oop mounted_vt = thread->is_vthread_mounted() ? thread->vthread() : nullptr;
3087 if (mounted_vt != nullptr && !ThreadDumper::should_dump_vthread(mounted_vt)) {
3088 mounted_vt = nullptr;
3089 }
3090
3091 // mounted vthread (if any)
3092 if (mounted_vt != nullptr) {
3093 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::MountedVirtual, thread, mounted_vt);
3094 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3095 if (add_oom_frame) {
3096 thread_dumper->add_oom_frame(_oome_constructor);
3097 // we add oom frame to the VT stack, don't add it to the carrier thread stack
3098 add_oom_frame = false;
3099 }
3100 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3101 thread_dumper->dump_stack_traces(writer, _klass_map);
3102 }
3103
3104 // platform or carrier thread
3105 ThreadDumper* thread_dumper = new ThreadDumper(ThreadDumper::ThreadType::Platform, thread, thread->threadObj());
3106 _thread_dumpers[_thread_dumpers_count++] = thread_dumper;
3107 if (add_oom_frame) {
3108 thread_dumper->add_oom_frame(_oome_constructor);
3109 }
3110 thread_dumper->init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3111 thread_dumper->dump_stack_traces(writer, _klass_map);
3112 }
3113 }
3114 }
3115
3116 void VM_HeapDumper::dump_vthread(oop vt, AbstractDumpWriter* segment_writer) {
3117 // unmounted vthread has no JavaThread
3118 ThreadDumper thread_dumper(ThreadDumper::ThreadType::UnmountedVirtual, nullptr, vt);
3119 thread_dumper.init_serial_nums(&_thread_serial_num, &_frame_serial_num);
3120
3121 // write HPROF_TRACE/HPROF_FRAME records to global writer
3122 _dumper_controller->lock_global_writer();
3123 thread_dumper.dump_stack_traces(writer(), _klass_map);
3124 _dumper_controller->unlock_global_writer();
3125
3126 // write HPROF_GC_ROOT_THREAD_OBJ/HPROF_GC_ROOT_JAVA_FRAME/HPROF_GC_ROOT_JNI_LOCAL subrecord
3127 // to segment writer
3128 thread_dumper.dump_thread_obj(segment_writer);
3129 thread_dumper.dump_stack_refs(segment_writer);
3130 }
3131
3132 // dump the heap to given path.
3133 int HeapDumper::dump(const char* path, outputStream* out, int compression, bool overwrite, uint num_dump_threads) {
3134 assert(path != nullptr && strlen(path) > 0, "path missing");
3135
3136 // print message in interactive case
3137 if (out != nullptr) {
3138 out->print_cr("Dumping heap to %s ...", path);
3139 timer()->start();
3140 }
3141 // create JFR event
3142 EventHeapDump event;
3143
3144 AbstractCompressor* compressor = nullptr;
3145
3146 if (compression > 0) {
3147 compressor = new (std::nothrow) GZipCompressor(compression);
3148
3149 if (compressor == nullptr) {
3150 set_error("Could not allocate gzip compressor");
3151 return -1;
3152 }
3153 }
3154
3155 DumpWriter writer(path, overwrite, compressor);
3156
3157 if (writer.error() != nullptr) {
3158 set_error(writer.error());
3159 if (out != nullptr) {
3160 out->print_cr("Unable to create %s: %s", path,
3161 (error() != nullptr) ? error() : "reason unknown");
3162 }
3163 return -1;
3164 }
3165
3166 // generate the segmented heap dump into separate files
3167 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome, num_dump_threads);
3168 VMThread::execute(&dumper);
3169
3170 // record any error that the writer may have encountered
3171 set_error(writer.error());
3172
3173 // Heap dump process is done in two phases
3174 //
3175 // Phase 1: Concurrent threads directly write heap data to multiple heap files.
3176 // This is done by VM_HeapDumper, which is performed within safepoint.
3177 //
3178 // Phase 2: Merge multiple heap files into one complete heap dump file.
3179 // This is done by DumpMerger, which is performed outside safepoint
3180
3181 DumpMerger merger(path, &writer, dumper.inlined_objects(), dumper.dump_seq());
3182 Thread* current_thread = Thread::current();
3183 if (current_thread->is_AttachListener_thread()) {
3184 // perform heapdump file merge operation in the current thread prevents us
3185 // from occupying the VM Thread, which in turn affects the occurrence of
3186 // GC and other VM operations.
3187 merger.do_merge();
3188 } else {
3189 // otherwise, performs it by VM thread
3190 VM_HeapDumpMerge op(&merger);
3191 VMThread::execute(&op);
3192 }
3193 if (writer.error() != nullptr) {
3194 set_error(writer.error());
3195 }
3196
3197 // emit JFR event
3198 if (error() == nullptr) {
3199 event.set_destination(path);
3200 event.set_gcBeforeDump(_gc_before_heap_dump);
3201 event.set_size(writer.bytes_written());
3202 event.set_onOutOfMemoryError(_oome);
3203 event.set_overwrite(overwrite);
3204 event.set_compression(compression);
3205 event.commit();
3206 } else {
3207 log_debug(cds, heap)("Error %s while dumping heap", error());
3208 }
3209
3210 // print message in interactive case
3211 if (out != nullptr) {
3212 timer()->stop();
3213 if (error() == nullptr) {
3214 out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
3215 writer.bytes_written(), timer()->seconds());
3216 } else {
3217 out->print_cr("Dump file is incomplete: %s", writer.error());
3218 }
3219 }
3220
3221 if (compressor != nullptr) {
3222 delete compressor;
3223 }
3224 return (writer.error() == nullptr) ? 0 : -1;
3225 }
3226
3227 // stop timer (if still active), and free any error string we might be holding
3228 HeapDumper::~HeapDumper() {
3229 if (timer()->is_active()) {
3230 timer()->stop();
3231 }
3232 set_error(nullptr);
3233 }
3234
3235
3236 // returns the error string (resource allocated), or null
3237 char* HeapDumper::error_as_C_string() const {
3238 if (error() != nullptr) {
3239 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
3240 strcpy(str, error());
3241 return str;
3242 } else {
3243 return nullptr;
3244 }
3245 }
3246
3247 // set the error string
3248 void HeapDumper::set_error(char const* error) {
3249 if (_error != nullptr) {
3250 os::free(_error);
3251 }
3252 if (error == nullptr) {
3253 _error = nullptr;
3254 } else {
3255 _error = os::strdup(error);
3256 assert(_error != nullptr, "allocation failure");
3257 }
3258 }
3259
3260 // Called by out-of-memory error reporting by a single Java thread
3261 // outside of a JVM safepoint
3262 void HeapDumper::dump_heap_from_oome() {
3263 HeapDumper::dump_heap(true);
3264 }
3265
3266 // Called by error reporting by a single Java thread outside of a JVM safepoint,
3267 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
3268 // callers are strictly serialized and guaranteed not to interfere below. For more
3269 // general use, however, this method will need modification to prevent
3270 // inteference when updating the static variables base_path and dump_file_seq below.
3271 void HeapDumper::dump_heap() {
3272 HeapDumper::dump_heap(false);
3273 }
3274
3275 void HeapDumper::dump_heap(bool oome) {
3276 static char base_path[JVM_MAXPATHLEN] = {'\0'};
3277 static uint dump_file_seq = 0;
3278 char* my_path;
3279 const int max_digit_chars = 20;
3280
3281 const char* dump_file_name = "java_pid";
3282 const char* dump_file_ext = HeapDumpGzipLevel > 0 ? ".hprof.gz" : ".hprof";
3283
3284 // The dump file defaults to java_pid<pid>.hprof in the current working
3285 // directory. HeapDumpPath=<file> can be used to specify an alternative
3286 // dump file name or a directory where dump file is created.
3287 if (dump_file_seq == 0) { // first time in, we initialize base_path
3288 // Calculate potentially longest base path and check if we have enough
3289 // allocated statically.
3290 const size_t total_length =
3291 (HeapDumpPath == nullptr ? 0 : strlen(HeapDumpPath)) +
3292 strlen(os::file_separator()) + max_digit_chars +
3293 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
3294 if (total_length > sizeof(base_path)) {
3295 warning("Cannot create heap dump file. HeapDumpPath is too long.");
3296 return;
3297 }
3298
3299 bool use_default_filename = true;
3300 if (HeapDumpPath == nullptr || HeapDumpPath[0] == '\0') {
3301 // HeapDumpPath=<file> not specified
3302 } else {
3303 strcpy(base_path, HeapDumpPath);
3304 // check if the path is a directory (must exist)
3305 DIR* dir = os::opendir(base_path);
3306 if (dir == nullptr) {
3307 use_default_filename = false;
3308 } else {
3309 // HeapDumpPath specified a directory. We append a file separator
3310 // (if needed).
3311 os::closedir(dir);
3312 size_t fs_len = strlen(os::file_separator());
3313 if (strlen(base_path) >= fs_len) {
3314 char* end = base_path;
3315 end += (strlen(base_path) - fs_len);
3316 if (strcmp(end, os::file_separator()) != 0) {
3317 strcat(base_path, os::file_separator());
3318 }
3319 }
3320 }
3321 }
3322 // If HeapDumpPath wasn't a file name then we append the default name
3323 if (use_default_filename) {
3324 const size_t dlen = strlen(base_path); // if heap dump dir specified
3325 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
3326 dump_file_name, os::current_process_id(), dump_file_ext);
3327 }
3328 const size_t len = strlen(base_path) + 1;
3329 my_path = (char*)os::malloc(len, mtInternal);
3330 if (my_path == nullptr) {
3331 warning("Cannot create heap dump file. Out of system memory.");
3332 return;
3333 }
3334 strncpy(my_path, base_path, len);
3335 } else {
3336 // Append a sequence number id for dumps following the first
3337 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
3338 my_path = (char*)os::malloc(len, mtInternal);
3339 if (my_path == nullptr) {
3340 warning("Cannot create heap dump file. Out of system memory.");
3341 return;
3342 }
3343 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
3344 }
3345 dump_file_seq++; // increment seq number for next time we dump
3346
3347 HeapDumper dumper(false /* no GC before heap dump */,
3348 oome /* pass along out-of-memory-error flag */);
3349 dumper.dump(my_path, tty, HeapDumpGzipLevel);
3350 os::free(my_path);
3351 }