1 /*
2 * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
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/systemDictionary.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "jfr/jfrEvents.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "memory/universe.hpp"
39 #include "oops/objArrayKlass.hpp"
40 #include "oops/objArrayOop.inline.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "oops/typeArrayOop.inline.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/javaCalls.hpp"
46 #include "runtime/jniHandles.hpp"
47 #include "runtime/os.inline.hpp"
48 #include "runtime/reflectionUtils.hpp"
49 #include "runtime/thread.inline.hpp"
50 #include "runtime/threadSMR.hpp"
51 #include "runtime/vframe.hpp"
52 #include "runtime/vmThread.hpp"
53 #include "runtime/vmOperations.hpp"
54 #include "services/heapDumper.hpp"
55 #include "services/threadService.hpp"
56 #include "utilities/macros.hpp"
57 #include "utilities/ostream.hpp"
58
59 /*
60 * HPROF binary format - description copied from:
61 * src/share/demo/jvmti/hprof/hprof_io.c
62 *
63 *
64 * header "JAVA PROFILE 1.0.2" (0-terminated)
65 *
66 * u4 size of identifiers. Identifiers are used to represent
67 * UTF8 strings, objects, stack traces, etc. They usually
68 * have the same size as host pointers. For example, on
69 * Solaris and Win32, the size is 4.
70 * u4 high word
71 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
72 * [record]* a sequence of records.
73 *
74 *
75 * Record format:
76 *
77 * u1 a TAG denoting the type of the record
78 * u4 number of *microseconds* since the time stamp in the
79 * header. (wraps around in a little more than an hour)
80 * u4 number of bytes *remaining* in the record. Note that
81 * this number excludes the tag and the length field itself.
82 * [u1]* BODY of the record (a sequence of bytes)
83 *
84 *
85 * The following TAGs are supported:
86 *
87 * TAG BODY notes
88 *----------------------------------------------------------
89 * HPROF_UTF8 a UTF8-encoded name
90 *
91 * id name ID
92 * [u1]* UTF8 characters (no trailing zero)
93 *
94 * HPROF_LOAD_CLASS a newly loaded class
95 *
96 * u4 class serial number (> 0)
97 * id class object ID
98 * u4 stack trace serial number
99 * id class name ID
100 *
101 * HPROF_UNLOAD_CLASS an unloading class
102 *
103 * u4 class serial_number
104 *
105 * HPROF_FRAME a Java stack frame
106 *
107 * id stack frame ID
108 * id method name ID
109 * id method signature ID
110 * id source file name ID
111 * u4 class serial number
112 * i4 line number. >0: normal
113 * -1: unknown
114 * -2: compiled method
115 * -3: native method
116 *
117 * HPROF_TRACE a Java stack trace
118 *
119 * u4 stack trace serial number
120 * u4 thread serial number
121 * u4 number of frames
122 * [id]* stack frame IDs
123 *
124 *
125 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
126 *
127 * u2 flags 0x0001: incremental vs. complete
128 * 0x0002: sorted by allocation vs. live
129 * 0x0004: whether to force a GC
130 * u4 cutoff ratio
131 * u4 total live bytes
132 * u4 total live instances
133 * u8 total bytes allocated
134 * u8 total instances allocated
135 * u4 number of sites that follow
136 * [u1 is_array: 0: normal object
137 * 2: object array
138 * 4: boolean array
139 * 5: char array
140 * 6: float array
141 * 7: double array
142 * 8: byte array
143 * 9: short array
144 * 10: int array
145 * 11: long array
146 * u4 class serial number (may be zero during startup)
147 * u4 stack trace serial number
148 * u4 number of bytes alive
149 * u4 number of instances alive
150 * u4 number of bytes allocated
151 * u4]* number of instance allocated
152 *
153 * HPROF_START_THREAD a newly started thread.
154 *
155 * u4 thread serial number (> 0)
156 * id thread object ID
157 * u4 stack trace serial number
158 * id thread name ID
159 * id thread group name ID
160 * id thread group parent name ID
161 *
162 * HPROF_END_THREAD a terminating thread.
163 *
164 * u4 thread serial number
165 *
166 * HPROF_HEAP_SUMMARY heap summary
167 *
168 * u4 total live bytes
169 * u4 total live instances
170 * u8 total bytes allocated
171 * u8 total instances allocated
172 *
173 * HPROF_HEAP_DUMP denote a heap dump
174 *
175 * [heap dump sub-records]*
176 *
177 * There are four kinds of heap dump sub-records:
178 *
179 * u1 sub-record type
180 *
181 * HPROF_GC_ROOT_UNKNOWN unknown root
182 *
183 * id object ID
184 *
185 * HPROF_GC_ROOT_THREAD_OBJ thread object
186 *
187 * id thread object ID (may be 0 for a
188 * thread newly attached through JNI)
189 * u4 thread sequence number
190 * u4 stack trace sequence number
191 *
192 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
193 *
194 * id object ID
195 * id JNI global ref ID
196 *
197 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
198 *
199 * id object ID
200 * u4 thread serial number
201 * u4 frame # in stack trace (-1 for empty)
202 *
203 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
204 *
205 * id object ID
206 * u4 thread serial number
207 * u4 frame # in stack trace (-1 for empty)
208 *
209 * HPROF_GC_ROOT_NATIVE_STACK Native stack
210 *
211 * id object ID
212 * u4 thread serial number
213 *
214 * HPROF_GC_ROOT_STICKY_CLASS System class
215 *
216 * id object ID
217 *
218 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
219 *
220 * id object ID
221 * u4 thread serial number
222 *
223 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
224 *
225 * id object ID
226 *
227 * HPROF_GC_CLASS_DUMP dump of a class object
228 *
229 * id class object ID
230 * u4 stack trace serial number
231 * id super class object ID
232 * id class loader object ID
233 * id signers object ID
234 * id protection domain object ID
235 * id reserved
236 * id reserved
237 *
238 * u4 instance size (in bytes)
239 *
240 * u2 size of constant pool
241 * [u2, constant pool index,
242 * ty, type
243 * 2: object
244 * 4: boolean
245 * 5: char
246 * 6: float
247 * 7: double
248 * 8: byte
249 * 9: short
250 * 10: int
251 * 11: long
252 * vl]* and value
253 *
254 * u2 number of static fields
255 * [id, static field name,
256 * ty, type,
257 * vl]* and value
258 *
259 * u2 number of inst. fields (not inc. super)
260 * [id, instance field name,
261 * ty]* type
262 *
263 * HPROF_GC_INSTANCE_DUMP dump of a normal object
264 *
265 * id object ID
266 * u4 stack trace serial number
267 * id class object ID
268 * u4 number of bytes that follow
269 * [vl]* instance field values (class, followed
270 * by super, super's super ...)
271 *
272 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
273 *
274 * id array object ID
275 * u4 stack trace serial number
276 * u4 number of elements
277 * id array class ID
278 * [id]* elements
279 *
280 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
281 *
282 * id array object ID
283 * u4 stack trace serial number
284 * u4 number of elements
285 * u1 element type
286 * 4: boolean array
287 * 5: char array
288 * 6: float array
289 * 7: double array
290 * 8: byte array
291 * 9: short array
292 * 10: int array
293 * 11: long array
294 * [u1]* elements
295 *
296 * HPROF_CPU_SAMPLES a set of sample traces of running threads
297 *
298 * u4 total number of samples
299 * u4 # of traces
300 * [u4 # of samples
301 * u4]* stack trace serial number
302 *
303 * HPROF_CONTROL_SETTINGS the settings of on/off switches
304 *
305 * u4 0x00000001: alloc traces on/off
306 * 0x00000002: cpu sampling on/off
307 * u2 stack trace depth
308 *
309 *
310 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
311 * be generated as a sequence of heap dump segments. This sequence is
312 * terminated by an end record. The additional tags allowed by format
313 * "JAVA PROFILE 1.0.2" are:
314 *
315 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
316 *
317 * [heap dump sub-records]*
318 * The same sub-record types allowed by HPROF_HEAP_DUMP
319 *
320 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
321 *
322 */
323
324
325 // HPROF tags
326
327 typedef enum {
328 // top-level records
329 HPROF_UTF8 = 0x01,
330 HPROF_LOAD_CLASS = 0x02,
331 HPROF_UNLOAD_CLASS = 0x03,
332 HPROF_FRAME = 0x04,
333 HPROF_TRACE = 0x05,
334 HPROF_ALLOC_SITES = 0x06,
335 HPROF_HEAP_SUMMARY = 0x07,
336 HPROF_START_THREAD = 0x0A,
337 HPROF_END_THREAD = 0x0B,
338 HPROF_HEAP_DUMP = 0x0C,
339 HPROF_CPU_SAMPLES = 0x0D,
340 HPROF_CONTROL_SETTINGS = 0x0E,
341
342 // 1.0.2 record types
343 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
344 HPROF_HEAP_DUMP_END = 0x2C,
345
346 // field types
347 HPROF_ARRAY_OBJECT = 0x01,
348 HPROF_NORMAL_OBJECT = 0x02,
349 HPROF_BOOLEAN = 0x04,
350 HPROF_CHAR = 0x05,
351 HPROF_FLOAT = 0x06,
352 HPROF_DOUBLE = 0x07,
353 HPROF_BYTE = 0x08,
354 HPROF_SHORT = 0x09,
355 HPROF_INT = 0x0A,
356 HPROF_LONG = 0x0B,
357
358 // data-dump sub-records
359 HPROF_GC_ROOT_UNKNOWN = 0xFF,
360 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
361 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
362 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
363 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
364 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
365 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
366 HPROF_GC_ROOT_MONITOR_USED = 0x07,
367 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
368 HPROF_GC_CLASS_DUMP = 0x20,
369 HPROF_GC_INSTANCE_DUMP = 0x21,
370 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
371 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
372 } hprofTag;
373
374 // Default stack trace ID (used for dummy HPROF_TRACE record)
375 enum {
376 STACK_TRACE_ID = 1,
377 INITIAL_CLASS_COUNT = 200
378 };
379
380 // Supports I/O operations on a dump file
381
382 class DumpWriter : public StackObj {
383 private:
384 enum {
385 io_buffer_max_size = 8*M,
386 io_buffer_min_size = 64*K,
387 dump_segment_header_size = 9
388 };
389
390 int _fd; // file descriptor (-1 if dump file not open)
391 julong _bytes_written; // number of byte written to dump file
392
393 char* _buffer; // internal buffer
394 size_t _size;
395 size_t _pos;
396
397 bool _in_dump_segment; // Are we currently in a dump segment?
398 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
399 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
400 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
401
402 char* _error; // error message when I/O fails
403
404 void set_file_descriptor(int fd) { _fd = fd; }
405 int file_descriptor() const { return _fd; }
406
407 bool is_open() const { return file_descriptor() >= 0; }
408 void flush();
409
410 char* buffer() const { return _buffer; }
411 size_t buffer_size() const { return _size; }
412 size_t position() const { return _pos; }
413 void set_position(size_t pos) { _pos = pos; }
414
415 void set_error(const char* error) { _error = (char*)os::strdup(error); }
416
417 // all I/O go through this function
418 void write_internal(void* s, size_t len);
419
420 public:
421 DumpWriter(const char* path);
422 ~DumpWriter();
423
424 void close();
425
426 // total number of bytes written to the disk
427 julong bytes_written() const { return _bytes_written; }
428
429 char* error() const { return _error; }
430
431 // writer functions
432 void write_raw(void* s, size_t len);
433 void write_u1(u1 x) { write_raw((void*)&x, 1); }
434 void write_u2(u2 x);
435 void write_u4(u4 x);
436 void write_u8(u8 x);
437 void write_objectID(oop o);
438 void write_symbolID(Symbol* o);
439 void write_classID(Klass* k);
440 void write_id(u4 x);
441
442 // Start a new sub-record. Starts a new heap dump segment if needed.
443 void start_sub_record(u1 tag, u4 len);
444 // Ends the current sub-record.
445 void end_sub_record();
446 // Finishes the current dump segment if not already finished.
447 void finish_dump_segment();
448 };
449
450 DumpWriter::DumpWriter(const char* path) : _fd(-1), _bytes_written(0), _pos(0),
451 _in_dump_segment(false), _error(NULL) {
452 // try to allocate an I/O buffer of io_buffer_size. If there isn't
453 // sufficient memory then reduce size until we can allocate something.
454 _size = io_buffer_max_size;
455 do {
456 _buffer = (char*)os::malloc(_size, mtInternal);
457 if (_buffer == NULL) {
458 _size = _size >> 1;
459 }
460 } while (_buffer == NULL && _size >= io_buffer_min_size);
461
462 if (_buffer == NULL) {
463 set_error("Could not allocate buffer memory for heap dump");
464 } else {
465 _fd = os::create_binary_file(path, false); // don't replace existing file
466
467 // if the open failed we record the error
468 if (_fd < 0) {
469 set_error(os::strerror(errno));
470 }
471 }
472 }
473
474 DumpWriter::~DumpWriter() {
475 close();
476 os::free(_buffer);
477 os::free(_error);
478 }
479
480 // closes dump file (if open)
481 void DumpWriter::close() {
482 // flush and close dump file
483 if (is_open()) {
484 flush();
485 os::close(file_descriptor());
486 set_file_descriptor(-1);
487 }
488 }
489
490 // write directly to the file
491 void DumpWriter::write_internal(void* s, size_t len) {
492 if (is_open()) {
493 const char* pos = (char*)s;
494 ssize_t n = 0;
495 while (len > 0) {
496 uint tmp = (uint)MIN2(len, (size_t)INT_MAX);
497 n = os::write(file_descriptor(), pos, tmp);
498
499 if (n < 0) {
500 // EINTR cannot happen here, os::write will take care of that
501 set_error(os::strerror(errno));
502 os::close(file_descriptor());
503 set_file_descriptor(-1);
504 return;
505 }
506
507 _bytes_written += n;
508 pos += n;
509 len -= n;
510 }
511 }
512 }
513
514 // write raw bytes
515 void DumpWriter::write_raw(void* s, size_t len) {
516 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
517 debug_only(_sub_record_left -= len);
518
519 // flush buffer to make room
520 if (len > buffer_size() - position()) {
521 assert(!_in_dump_segment || _is_huge_sub_record, "Cannot overflow in non-huge sub-record.");
522 flush();
523
524 // If larger than the buffer, just write it directly.
525 if (len > buffer_size()) {
526 write_internal(s, len);
527
528 return;
529 }
530 }
531
532 memcpy(buffer() + position(), s, len);
533 set_position(position() + len);
534 }
535
536 // flush any buffered bytes to the file
537 void DumpWriter::flush() {
538 write_internal(buffer(), position());
539 set_position(0);
540 }
541
542 void DumpWriter::write_u2(u2 x) {
543 u2 v;
544 Bytes::put_Java_u2((address)&v, x);
545 write_raw((void*)&v, 2);
546 }
547
548 void DumpWriter::write_u4(u4 x) {
549 u4 v;
550 Bytes::put_Java_u4((address)&v, x);
551 write_raw((void*)&v, 4);
552 }
553
554 void DumpWriter::write_u8(u8 x) {
555 u8 v;
556 Bytes::put_Java_u8((address)&v, x);
557 write_raw((void*)&v, 8);
558 }
559
560 void DumpWriter::write_objectID(oop o) {
561 address a = cast_from_oop<address>(o);
562 #ifdef _LP64
563 write_u8((u8)a);
564 #else
565 write_u4((u4)a);
566 #endif
567 }
568
569 void DumpWriter::write_symbolID(Symbol* s) {
570 address a = (address)((uintptr_t)s);
571 #ifdef _LP64
572 write_u8((u8)a);
573 #else
574 write_u4((u4)a);
575 #endif
576 }
577
578 void DumpWriter::write_id(u4 x) {
579 #ifdef _LP64
580 write_u8((u8) x);
581 #else
582 write_u4(x);
583 #endif
584 }
585
586 // We use java mirror as the class ID
587 void DumpWriter::write_classID(Klass* k) {
588 write_objectID(k->java_mirror());
589 }
590
591 void DumpWriter::finish_dump_segment() {
592 if (_in_dump_segment) {
593 assert(_sub_record_left == 0, "Last sub-record not written completely");
594 assert(_sub_record_ended, "sub-record must have ended");
595
596 // Fix up the dump segment length if we haven't written a huge sub-record last
597 // (in which case the segment length was already set to the correct value initially).
598 if (!_is_huge_sub_record) {
599 assert(position() > dump_segment_header_size, "Dump segment should have some content");
600 Bytes::put_Java_u4((address) (buffer() + 5), (u4) (position() - dump_segment_header_size));
601 }
602
603 flush();
604 _in_dump_segment = false;
605 }
606 }
607
608 void DumpWriter::start_sub_record(u1 tag, u4 len) {
609 if (!_in_dump_segment) {
610 if (position() > 0) {
611 flush();
612 assert(position() == 0, "Must be at the start");
613 }
614
615 write_u1(HPROF_HEAP_DUMP_SEGMENT);
616 write_u4(0); // timestamp
617 // Will be fixed up later if we add more sub-records. If this is a huge sub-record,
618 // this is already the correct length, since we don't add more sub-records.
619 write_u4(len);
620 _in_dump_segment = true;
621 _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
622 } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
623 // This object will not fit in completely or the last sub-record was huge.
624 // Finish the current segement and try again.
625 finish_dump_segment();
626 start_sub_record(tag, len);
627
628 return;
629 }
630
631 debug_only(_sub_record_left = len);
632 debug_only(_sub_record_ended = false);
633
634 write_u1(tag);
635 }
636
637 void DumpWriter::end_sub_record() {
638 assert(_in_dump_segment, "must be in dump segment");
639 assert(_sub_record_left == 0, "sub-record not written completely");
640 assert(!_sub_record_ended, "Must not have ended yet");
641 debug_only(_sub_record_ended = true);
642 }
643
644 // Support class with a collection of functions used when dumping the heap
645
646 class DumperSupport : AllStatic {
647 public:
648
649 // write a header of the given type
650 static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
651
652 // returns hprof tag for the given type signature
653 static hprofTag sig2tag(Symbol* sig);
654 // returns hprof tag for the given basic type
655 static hprofTag type2tag(BasicType type);
656 // Returns the size of the data to write.
657 static u4 sig2size(Symbol* sig);
658
659 // returns the size of the instance of the given class
660 static u4 instance_size(Klass* k);
661
662 // dump a jfloat
663 static void dump_float(DumpWriter* writer, jfloat f);
664 // dump a jdouble
665 static void dump_double(DumpWriter* writer, jdouble d);
666 // dumps the raw value of the given field
667 static void dump_field_value(DumpWriter* writer, char type, oop obj, int offset);
668 // returns the size of the static fields; also counts the static fields
669 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
670 // dumps static fields of the given class
671 static void dump_static_fields(DumpWriter* writer, Klass* k);
672 // dump the raw values of the instance fields of the given object
673 static void dump_instance_fields(DumpWriter* writer, oop o);
674 // get the count of the instance fields for a given class
675 static u2 get_instance_fields_count(InstanceKlass* ik);
676 // dumps the definition of the instance fields for a given class
677 static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k);
678 // creates HPROF_GC_INSTANCE_DUMP record for the given object
679 static void dump_instance(DumpWriter* writer, oop o);
680 // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
681 // array classes
682 static void dump_class_and_array_classes(DumpWriter* writer, Klass* k);
683 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
684 // class (and each multi-dimensional array class too)
685 static void dump_basic_type_array_class(DumpWriter* writer, Klass* k);
686
687 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
688 static void dump_object_array(DumpWriter* writer, objArrayOop array);
689 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
690 static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
691 // create HPROF_FRAME record for the given method and bci
692 static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
693
694 // check if we need to truncate an array
695 static int calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size);
696
697 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
698 static void end_of_dump(DumpWriter* writer);
699
700 static oop mask_dormant_archived_object(oop o) {
701 if (o != NULL && o->klass()->java_mirror() == NULL) {
702 // Ignore this object since the corresponding java mirror is not loaded.
703 // Might be a dormant archive object.
704 return NULL;
705 } else {
706 return o;
707 }
708 }
709 };
710
711 // write a header of the given type
712 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
713 writer->write_u1((u1)tag);
714 writer->write_u4(0); // current ticks
715 writer->write_u4(len);
716 }
717
718 // returns hprof tag for the given type signature
719 hprofTag DumperSupport::sig2tag(Symbol* sig) {
720 switch (sig->char_at(0)) {
721 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
722 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
723 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
724 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
725 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
726 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
727 case JVM_SIGNATURE_INT : return HPROF_INT;
728 case JVM_SIGNATURE_LONG : return HPROF_LONG;
729 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
730 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
731 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
732 }
733 }
734
735 hprofTag DumperSupport::type2tag(BasicType type) {
736 switch (type) {
737 case T_BYTE : return HPROF_BYTE;
738 case T_CHAR : return HPROF_CHAR;
739 case T_FLOAT : return HPROF_FLOAT;
740 case T_DOUBLE : return HPROF_DOUBLE;
741 case T_INT : return HPROF_INT;
742 case T_LONG : return HPROF_LONG;
743 case T_SHORT : return HPROF_SHORT;
744 case T_BOOLEAN : return HPROF_BOOLEAN;
745 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
746 }
747 }
748
749 u4 DumperSupport::sig2size(Symbol* sig) {
750 switch (sig->char_at(0)) {
751 case JVM_SIGNATURE_CLASS:
752 case JVM_SIGNATURE_ARRAY: return sizeof(address);
753 case JVM_SIGNATURE_BOOLEAN:
754 case JVM_SIGNATURE_BYTE: return 1;
755 case JVM_SIGNATURE_SHORT:
756 case JVM_SIGNATURE_CHAR: return 2;
757 case JVM_SIGNATURE_INT:
758 case JVM_SIGNATURE_FLOAT: return 4;
759 case JVM_SIGNATURE_LONG:
760 case JVM_SIGNATURE_DOUBLE: return 8;
761 default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
762 }
763 }
764
765 // dump a jfloat
766 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
767 if (g_isnan(f)) {
768 writer->write_u4(0x7fc00000); // collapsing NaNs
769 } else {
770 union {
771 int i;
772 float f;
773 } u;
774 u.f = (float)f;
775 writer->write_u4((u4)u.i);
776 }
777 }
778
779 // dump a jdouble
780 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
781 union {
782 jlong l;
783 double d;
784 } u;
785 if (g_isnan(d)) { // collapsing NaNs
786 u.l = (jlong)(0x7ff80000);
787 u.l = (u.l << 32);
788 } else {
789 u.d = (double)d;
790 }
791 writer->write_u8((u8)u.l);
792 }
793
794 // dumps the raw value of the given field
795 void DumperSupport::dump_field_value(DumpWriter* writer, char type, oop obj, int offset) {
796 switch (type) {
797 case JVM_SIGNATURE_CLASS :
798 case JVM_SIGNATURE_ARRAY : {
799 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
800 if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
801 ResourceMark rm;
802 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
803 p2i(o), o->klass()->external_name(),
804 p2i(obj), obj->klass()->external_name());
805 }
806 o = mask_dormant_archived_object(o);
807 assert(oopDesc::is_oop_or_null(o), "Expected an oop or NULL at " PTR_FORMAT, p2i(o));
808 writer->write_objectID(o);
809 break;
810 }
811 case JVM_SIGNATURE_BYTE : {
812 jbyte b = obj->byte_field(offset);
813 writer->write_u1((u1)b);
814 break;
815 }
816 case JVM_SIGNATURE_CHAR : {
817 jchar c = obj->char_field(offset);
818 writer->write_u2((u2)c);
819 break;
820 }
821 case JVM_SIGNATURE_SHORT : {
822 jshort s = obj->short_field(offset);
823 writer->write_u2((u2)s);
824 break;
825 }
826 case JVM_SIGNATURE_FLOAT : {
827 jfloat f = obj->float_field(offset);
828 dump_float(writer, f);
829 break;
830 }
831 case JVM_SIGNATURE_DOUBLE : {
832 jdouble d = obj->double_field(offset);
833 dump_double(writer, d);
834 break;
835 }
836 case JVM_SIGNATURE_INT : {
837 jint i = obj->int_field(offset);
838 writer->write_u4((u4)i);
839 break;
840 }
841 case JVM_SIGNATURE_LONG : {
842 jlong l = obj->long_field(offset);
843 writer->write_u8((u8)l);
844 break;
845 }
846 case JVM_SIGNATURE_BOOLEAN : {
847 jboolean b = obj->bool_field(offset);
848 writer->write_u1((u1)b);
849 break;
850 }
851 default : {
852 ShouldNotReachHere();
853 break;
854 }
855 }
856 }
857
858 // returns the size of the instance of the given class
859 u4 DumperSupport::instance_size(Klass* k) {
860 HandleMark hm;
861 InstanceKlass* ik = InstanceKlass::cast(k);
862 u4 size = 0;
863
864 for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
865 if (!fld.access_flags().is_static()) {
866 size += sig2size(fld.signature());
867 }
868 }
869 return size;
870 }
871
872 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
873 HandleMark hm;
874 field_count = 0;
875 u4 size = 0;
876
877 for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
878 if (fldc.access_flags().is_static()) {
879 field_count++;
880 size += sig2size(fldc.signature());
881 }
882 }
883
884 // Add in resolved_references which is referenced by the cpCache
885 // The resolved_references is an array per InstanceKlass holding the
886 // strings and other oops resolved from the constant pool.
887 oop resolved_references = ik->constants()->resolved_references_or_null();
888 if (resolved_references != NULL) {
889 field_count++;
890 size += sizeof(address);
891
892 // Add in the resolved_references of the used previous versions of the class
893 // in the case of RedefineClasses
894 InstanceKlass* prev = ik->previous_versions();
895 while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
896 field_count++;
897 size += sizeof(address);
898 prev = prev->previous_versions();
899 }
900 }
901
902 // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0]
903 // arrays.
904 oop init_lock = ik->init_lock();
905 if (init_lock != NULL) {
906 field_count++;
907 size += sizeof(address);
908 }
909
910 // We write the value itself plus a name and a one byte type tag per field.
911 return size + field_count * (sizeof(address) + 1);
912 }
913
914 // dumps static fields of the given class
915 void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) {
916 HandleMark hm;
917 InstanceKlass* ik = InstanceKlass::cast(k);
918
919 // dump the field descriptors and raw values
920 for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
921 if (fld.access_flags().is_static()) {
922 Symbol* sig = fld.signature();
923
924 writer->write_symbolID(fld.name()); // name
925 writer->write_u1(sig2tag(sig)); // type
926
927 // value
928 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
929 }
930 }
931
932 // Add resolved_references for each class that has them
933 oop resolved_references = ik->constants()->resolved_references_or_null();
934 if (resolved_references != NULL) {
935 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
936 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
937 writer->write_objectID(resolved_references);
938
939 // Also write any previous versions
940 InstanceKlass* prev = ik->previous_versions();
941 while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
942 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
943 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
944 writer->write_objectID(prev->constants()->resolved_references());
945 prev = prev->previous_versions();
946 }
947 }
948
949 // Add init lock to the end if the class is not yet initialized
950 oop init_lock = ik->init_lock();
951 if (init_lock != NULL) {
952 writer->write_symbolID(vmSymbols::init_lock_name()); // name
953 writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type
954 writer->write_objectID(init_lock);
955 }
956 }
957
958 // dump the raw values of the instance fields of the given object
959 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
960 HandleMark hm;
961 InstanceKlass* ik = InstanceKlass::cast(o->klass());
962
963 for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
964 if (!fld.access_flags().is_static()) {
965 Symbol* sig = fld.signature();
966 dump_field_value(writer, sig->char_at(0), o, fld.offset());
967 }
968 }
969 }
970
971 // dumps the definition of the instance fields for a given class
972 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
973 HandleMark hm;
974 u2 field_count = 0;
975
976 for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
977 if (!fldc.access_flags().is_static()) field_count++;
978 }
979
980 return field_count;
981 }
982
983 // dumps the definition of the instance fields for a given class
984 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) {
985 HandleMark hm;
986 InstanceKlass* ik = InstanceKlass::cast(k);
987
988 // dump the field descriptors
989 for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
990 if (!fld.access_flags().is_static()) {
991 Symbol* sig = fld.signature();
992
993 writer->write_symbolID(fld.name()); // name
994 writer->write_u1(sig2tag(sig)); // type
995 }
996 }
997 }
998
999 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1000 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
1001 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1002 u4 is = instance_size(ik);
1003 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1004
1005 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1006 writer->write_objectID(o);
1007 writer->write_u4(STACK_TRACE_ID);
1008
1009 // class ID
1010 writer->write_classID(ik);
1011
1012 // number of bytes that follow
1013 writer->write_u4(is);
1014
1015 // field values
1016 dump_instance_fields(writer, o);
1017
1018 writer->end_sub_record();
1019 }
1020
1021 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
1022 // its array classes
1023 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
1024 InstanceKlass* ik = InstanceKlass::cast(k);
1025
1026 // We can safepoint and do a heap dump at a point where we have a Klass,
1027 // but no java mirror class has been setup for it. So we need to check
1028 // that the class is at least loaded, to avoid crash from a null mirror.
1029 if (!ik->is_loaded()) {
1030 return;
1031 }
1032
1033 u2 static_fields_count = 0;
1034 u4 static_size = get_static_fields_size(ik, static_fields_count);
1035 u2 instance_fields_count = get_instance_fields_count(ik);
1036 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1037 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size;
1038
1039 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1040
1041 // class ID
1042 writer->write_classID(ik);
1043 writer->write_u4(STACK_TRACE_ID);
1044
1045 // super class ID
1046 InstanceKlass* java_super = ik->java_super();
1047 if (java_super == NULL) {
1048 writer->write_objectID(oop(NULL));
1049 } else {
1050 writer->write_classID(java_super);
1051 }
1052
1053 writer->write_objectID(ik->class_loader());
1054 writer->write_objectID(ik->signers());
1055 writer->write_objectID(ik->protection_domain());
1056
1057 // reserved
1058 writer->write_objectID(oop(NULL));
1059 writer->write_objectID(oop(NULL));
1060
1061 // instance size
1062 writer->write_u4(DumperSupport::instance_size(ik));
1063
1064 // size of constant pool - ignored by HAT 1.1
1065 writer->write_u2(0);
1066
1067 // static fields
1068 writer->write_u2(static_fields_count);
1069 dump_static_fields(writer, ik);
1070
1071 // description of instance fields
1072 writer->write_u2(instance_fields_count);
1073 dump_instance_field_descriptors(writer, ik);
1074
1075 writer->end_sub_record();
1076
1077 // array classes
1078 k = ik->array_klass_or_null();
1079 while (k != NULL) {
1080 assert(k->is_objArray_klass(), "not an ObjArrayKlass");
1081
1082 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1083 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1084 writer->write_classID(k);
1085 writer->write_u4(STACK_TRACE_ID);
1086
1087 // super class of array classes is java.lang.Object
1088 java_super = k->java_super();
1089 assert(java_super != NULL, "checking");
1090 writer->write_classID(java_super);
1091
1092 writer->write_objectID(ik->class_loader());
1093 writer->write_objectID(ik->signers());
1094 writer->write_objectID(ik->protection_domain());
1095
1096 writer->write_objectID(oop(NULL)); // reserved
1097 writer->write_objectID(oop(NULL));
1098 writer->write_u4(0); // instance size
1099 writer->write_u2(0); // constant pool
1100 writer->write_u2(0); // static fields
1101 writer->write_u2(0); // instance fields
1102
1103 writer->end_sub_record();
1104
1105 // get the array class for the next rank
1106 k = k->array_klass_or_null();
1107 }
1108 }
1109
1110 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
1111 // class (and each multi-dimensional array class too)
1112 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) {
1113 // array classes
1114 while (k != NULL) {
1115 Klass* klass = k;
1116
1117 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1118 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1119 writer->write_classID(klass);
1120 writer->write_u4(STACK_TRACE_ID);
1121
1122 // super class of array classes is java.lang.Object
1123 InstanceKlass* java_super = klass->java_super();
1124 assert(java_super != NULL, "checking");
1125 writer->write_classID(java_super);
1126
1127 writer->write_objectID(oop(NULL)); // loader
1128 writer->write_objectID(oop(NULL)); // signers
1129 writer->write_objectID(oop(NULL)); // protection domain
1130
1131 writer->write_objectID(oop(NULL)); // reserved
1132 writer->write_objectID(oop(NULL));
1133 writer->write_u4(0); // instance size
1134 writer->write_u2(0); // constant pool
1135 writer->write_u2(0); // static fields
1136 writer->write_u2(0); // instance fields
1137
1138 writer->end_sub_record();
1139
1140 // get the array class for the next rank
1141 k = klass->array_klass_or_null();
1142 }
1143 }
1144
1145 // Hprof uses an u4 as record length field,
1146 // which means we need to truncate arrays that are too long.
1147 int DumperSupport::calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size) {
1148 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1149 assert(type >= T_BOOLEAN && type <= T_OBJECT, "invalid array element type");
1150
1151 int length = array->length();
1152
1153 int type_size;
1154 if (type == T_OBJECT) {
1155 type_size = sizeof(address);
1156 } else {
1157 type_size = type2aelembytes(type);
1158 }
1159
1160 size_t length_in_bytes = (size_t)length * type_size;
1161 uint max_bytes = max_juint - header_size;
1162
1163 if (length_in_bytes > max_bytes) {
1164 length = max_bytes / type_size;
1165 length_in_bytes = (size_t)length * type_size;
1166
1167 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1168 type2name_tab[type], array->length(), length);
1169 }
1170 return length;
1171 }
1172
1173 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1174 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
1175 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1176 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1177 int length = calculate_array_max_length(writer, array, header_size);
1178 u4 size = header_size + length * sizeof(address);
1179
1180 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1181 writer->write_objectID(array);
1182 writer->write_u4(STACK_TRACE_ID);
1183 writer->write_u4(length);
1184
1185 // array class ID
1186 writer->write_classID(array->klass());
1187
1188 // [id]* elements
1189 for (int index = 0; index < length; index++) {
1190 oop o = array->obj_at(index);
1191 if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
1192 ResourceMark rm;
1193 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1194 p2i(o), o->klass()->external_name(),
1195 p2i(array), array->klass()->external_name());
1196 }
1197 o = mask_dormant_archived_object(o);
1198 writer->write_objectID(o);
1199 }
1200
1201 writer->end_sub_record();
1202 }
1203
1204 #define WRITE_ARRAY(Array, Type, Size, Length) \
1205 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1206
1207 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1208 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
1209 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1210
1211 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1212 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1213
1214 int length = calculate_array_max_length(writer, array, header_size);
1215 int type_size = type2aelembytes(type);
1216 u4 length_in_bytes = (u4)length * type_size;
1217 u4 size = header_size + length_in_bytes;
1218
1219 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1220 writer->write_objectID(array);
1221 writer->write_u4(STACK_TRACE_ID);
1222 writer->write_u4(length);
1223 writer->write_u1(type2tag(type));
1224
1225 // nothing to copy
1226 if (length == 0) {
1227 writer->end_sub_record();
1228 return;
1229 }
1230
1231 // If the byte ordering is big endian then we can copy most types directly
1232
1233 switch (type) {
1234 case T_INT : {
1235 if (Endian::is_Java_byte_ordering_different()) {
1236 WRITE_ARRAY(array, int, u4, length);
1237 } else {
1238 writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
1239 }
1240 break;
1241 }
1242 case T_BYTE : {
1243 writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
1244 break;
1245 }
1246 case T_CHAR : {
1247 if (Endian::is_Java_byte_ordering_different()) {
1248 WRITE_ARRAY(array, char, u2, length);
1249 } else {
1250 writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
1251 }
1252 break;
1253 }
1254 case T_SHORT : {
1255 if (Endian::is_Java_byte_ordering_different()) {
1256 WRITE_ARRAY(array, short, u2, length);
1257 } else {
1258 writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
1259 }
1260 break;
1261 }
1262 case T_BOOLEAN : {
1263 if (Endian::is_Java_byte_ordering_different()) {
1264 WRITE_ARRAY(array, bool, u1, length);
1265 } else {
1266 writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
1267 }
1268 break;
1269 }
1270 case T_LONG : {
1271 if (Endian::is_Java_byte_ordering_different()) {
1272 WRITE_ARRAY(array, long, u8, length);
1273 } else {
1274 writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
1275 }
1276 break;
1277 }
1278
1279 // handle float/doubles in a special value to ensure than NaNs are
1280 // written correctly. TO DO: Check if we can avoid this on processors that
1281 // use IEEE 754.
1282
1283 case T_FLOAT : {
1284 for (int i = 0; i < length; i++) {
1285 dump_float(writer, array->float_at(i));
1286 }
1287 break;
1288 }
1289 case T_DOUBLE : {
1290 for (int i = 0; i < length; i++) {
1291 dump_double(writer, array->double_at(i));
1292 }
1293 break;
1294 }
1295 default : ShouldNotReachHere();
1296 }
1297
1298 writer->end_sub_record();
1299 }
1300
1301 // create a HPROF_FRAME record of the given Method* and bci
1302 void DumperSupport::dump_stack_frame(DumpWriter* writer,
1303 int frame_serial_num,
1304 int class_serial_num,
1305 Method* m,
1306 int bci) {
1307 int line_number;
1308 if (m->is_native()) {
1309 line_number = -3; // native frame
1310 } else {
1311 line_number = m->line_number_from_bci(bci);
1312 }
1313
1314 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1315 writer->write_id(frame_serial_num); // frame serial number
1316 writer->write_symbolID(m->name()); // method's name
1317 writer->write_symbolID(m->signature()); // method's signature
1318
1319 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1320 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1321 writer->write_u4(class_serial_num); // class serial number
1322 writer->write_u4((u4) line_number); // line number
1323 }
1324
1325
1326 // Support class used to generate HPROF_UTF8 records from the entries in the
1327 // SymbolTable.
1328
1329 class SymbolTableDumper : public SymbolClosure {
1330 private:
1331 DumpWriter* _writer;
1332 DumpWriter* writer() const { return _writer; }
1333 public:
1334 SymbolTableDumper(DumpWriter* writer) { _writer = writer; }
1335 void do_symbol(Symbol** p);
1336 };
1337
1338 void SymbolTableDumper::do_symbol(Symbol** p) {
1339 ResourceMark rm;
1340 Symbol* sym = load_symbol(p);
1341 int len = sym->utf8_length();
1342 if (len > 0) {
1343 char* s = sym->as_utf8();
1344 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1345 writer()->write_symbolID(sym);
1346 writer()->write_raw(s, len);
1347 }
1348 }
1349
1350 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1351
1352 class JNILocalsDumper : public OopClosure {
1353 private:
1354 DumpWriter* _writer;
1355 u4 _thread_serial_num;
1356 int _frame_num;
1357 DumpWriter* writer() const { return _writer; }
1358 public:
1359 JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
1360 _writer = writer;
1361 _thread_serial_num = thread_serial_num;
1362 _frame_num = -1; // default - empty stack
1363 }
1364 void set_frame_number(int n) { _frame_num = n; }
1365 void do_oop(oop* obj_p);
1366 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1367 };
1368
1369
1370 void JNILocalsDumper::do_oop(oop* obj_p) {
1371 // ignore null handles
1372 oop o = *obj_p;
1373 if (o != NULL) {
1374 u4 size = 1 + sizeof(address) + 4 + 4;
1375 writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
1376 writer()->write_objectID(o);
1377 writer()->write_u4(_thread_serial_num);
1378 writer()->write_u4((u4)_frame_num);
1379 writer()->end_sub_record();
1380 }
1381 }
1382
1383
1384 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
1385
1386 class JNIGlobalsDumper : public OopClosure {
1387 private:
1388 DumpWriter* _writer;
1389 DumpWriter* writer() const { return _writer; }
1390
1391 public:
1392 JNIGlobalsDumper(DumpWriter* writer) {
1393 _writer = writer;
1394 }
1395 void do_oop(oop* obj_p);
1396 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1397 };
1398
1399 void JNIGlobalsDumper::do_oop(oop* obj_p) {
1400 oop o = *obj_p;
1401
1402 // ignore these
1403 if (o == NULL) return;
1404
1405 // we ignore global ref to symbols and other internal objects
1406 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
1407 u4 size = 1 + 2 * sizeof(address);
1408 writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
1409 writer()->write_objectID(o);
1410 writer()->write_objectID((oopDesc*)obj_p); // global ref ID
1411 writer()->end_sub_record();
1412 }
1413 };
1414
1415
1416 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
1417
1418 class MonitorUsedDumper : public OopClosure {
1419 private:
1420 DumpWriter* _writer;
1421 DumpWriter* writer() const { return _writer; }
1422 public:
1423 MonitorUsedDumper(DumpWriter* writer) {
1424 _writer = writer;
1425 }
1426 void do_oop(oop* obj_p) {
1427 u4 size = 1 + sizeof(address);
1428 writer()->start_sub_record(HPROF_GC_ROOT_MONITOR_USED, size);
1429 writer()->write_objectID(*obj_p);
1430 writer()->end_sub_record();
1431 }
1432 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1433 };
1434
1435
1436 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
1437
1438 class StickyClassDumper : public KlassClosure {
1439 private:
1440 DumpWriter* _writer;
1441 DumpWriter* writer() const { return _writer; }
1442 public:
1443 StickyClassDumper(DumpWriter* writer) {
1444 _writer = writer;
1445 }
1446 void do_klass(Klass* k) {
1447 if (k->is_instance_klass()) {
1448 InstanceKlass* ik = InstanceKlass::cast(k);
1449 u4 size = 1 + sizeof(address);
1450 writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
1451 writer()->write_classID(ik);
1452 writer()->end_sub_record();
1453 }
1454 }
1455 };
1456
1457
1458 class VM_HeapDumper;
1459
1460 // Support class using when iterating over the heap.
1461
1462 class HeapObjectDumper : public ObjectClosure {
1463 private:
1464 VM_HeapDumper* _dumper;
1465 DumpWriter* _writer;
1466
1467 VM_HeapDumper* dumper() { return _dumper; }
1468 DumpWriter* writer() { return _writer; }
1469
1470 public:
1471 HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
1472 _dumper = dumper;
1473 _writer = writer;
1474 }
1475
1476 // called for each object in the heap
1477 void do_object(oop o);
1478 };
1479
1480 void HeapObjectDumper::do_object(oop o) {
1481 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
1482 if (o->klass() == SystemDictionary::Class_klass()) {
1483 if (!java_lang_Class::is_primitive(o)) {
1484 return;
1485 }
1486 }
1487
1488 if (DumperSupport::mask_dormant_archived_object(o) == NULL) {
1489 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)", p2i(o), o->klass()->external_name());
1490 return;
1491 }
1492
1493 if (o->is_instance()) {
1494 // create a HPROF_GC_INSTANCE record for each object
1495 DumperSupport::dump_instance(writer(), o);
1496 } else if (o->is_objArray()) {
1497 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
1498 DumperSupport::dump_object_array(writer(), objArrayOop(o));
1499 } else if (o->is_typeArray()) {
1500 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
1501 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
1502 }
1503 }
1504
1505 // The VM operation that performs the heap dump
1506 class VM_HeapDumper : public VM_GC_Operation {
1507 private:
1508 static VM_HeapDumper* _global_dumper;
1509 static DumpWriter* _global_writer;
1510 DumpWriter* _local_writer;
1511 JavaThread* _oome_thread;
1512 Method* _oome_constructor;
1513 bool _gc_before_heap_dump;
1514 GrowableArray<Klass*>* _klass_map;
1515 ThreadStackTrace** _stack_traces;
1516 int _num_threads;
1517
1518 // accessors and setters
1519 static VM_HeapDumper* dumper() { assert(_global_dumper != NULL, "Error"); return _global_dumper; }
1520 static DumpWriter* writer() { assert(_global_writer != NULL, "Error"); return _global_writer; }
1521 void set_global_dumper() {
1522 assert(_global_dumper == NULL, "Error");
1523 _global_dumper = this;
1524 }
1525 void set_global_writer() {
1526 assert(_global_writer == NULL, "Error");
1527 _global_writer = _local_writer;
1528 }
1529 void clear_global_dumper() { _global_dumper = NULL; }
1530 void clear_global_writer() { _global_writer = NULL; }
1531
1532 bool skip_operation() const;
1533
1534 // writes a HPROF_LOAD_CLASS record
1535 class ClassesDo;
1536 static void do_load_class(Klass* k);
1537
1538 // writes a HPROF_GC_CLASS_DUMP record for the given class
1539 // (and each array class too)
1540 static void do_class_dump(Klass* k);
1541
1542 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1543 // array (and each multi-dimensional array too)
1544 static void do_basic_type_array_class_dump(Klass* k);
1545
1546 // HPROF_GC_ROOT_THREAD_OBJ records
1547 int do_thread(JavaThread* thread, u4 thread_serial_num);
1548 void do_threads();
1549
1550 void add_class_serial_number(Klass* k, int serial_num) {
1551 _klass_map->at_put_grow(serial_num, k);
1552 }
1553
1554 // HPROF_TRACE and HPROF_FRAME records
1555 void dump_stack_traces();
1556
1557 public:
1558 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
1559 VM_GC_Operation(0 /* total collections, dummy, ignored */,
1560 GCCause::_heap_dump /* GC Cause */,
1561 0 /* total full collections, dummy, ignored */,
1562 gc_before_heap_dump) {
1563 _local_writer = writer;
1564 _gc_before_heap_dump = gc_before_heap_dump;
1565 _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
1566 _stack_traces = NULL;
1567 _num_threads = 0;
1568 if (oome) {
1569 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
1570 // get OutOfMemoryError zero-parameter constructor
1571 InstanceKlass* oome_ik = SystemDictionary::OutOfMemoryError_klass();
1572 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
1573 vmSymbols::void_method_signature());
1574 // get thread throwing OOME when generating the heap dump at OOME
1575 _oome_thread = JavaThread::current();
1576 } else {
1577 _oome_thread = NULL;
1578 _oome_constructor = NULL;
1579 }
1580 }
1581 ~VM_HeapDumper() {
1582 if (_stack_traces != NULL) {
1583 for (int i=0; i < _num_threads; i++) {
1584 delete _stack_traces[i];
1585 }
1586 FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces);
1587 }
1588 delete _klass_map;
1589 }
1590
1591 VMOp_Type type() const { return VMOp_HeapDumper; }
1592 void doit();
1593 };
1594
1595 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
1596 DumpWriter* VM_HeapDumper::_global_writer = NULL;
1597
1598 bool VM_HeapDumper::skip_operation() const {
1599 return false;
1600 }
1601
1602 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
1603 void DumperSupport::end_of_dump(DumpWriter* writer) {
1604 writer->finish_dump_segment();
1605
1606 writer->write_u1(HPROF_HEAP_DUMP_END);
1607 writer->write_u4(0);
1608 writer->write_u4(0);
1609 }
1610
1611 // writes a HPROF_LOAD_CLASS record for the class (and each of its
1612 // array classes)
1613 void VM_HeapDumper::do_load_class(Klass* k) {
1614 static u4 class_serial_num = 0;
1615
1616 // len of HPROF_LOAD_CLASS record
1617 u4 remaining = 2*oopSize + 2*sizeof(u4);
1618
1619 // write a HPROF_LOAD_CLASS for the class and each array class
1620 do {
1621 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
1622
1623 // class serial number is just a number
1624 writer()->write_u4(++class_serial_num);
1625
1626 // class ID
1627 Klass* klass = k;
1628 writer()->write_classID(klass);
1629
1630 // add the Klass* and class serial number pair
1631 dumper()->add_class_serial_number(klass, class_serial_num);
1632
1633 writer()->write_u4(STACK_TRACE_ID);
1634
1635 // class name ID
1636 Symbol* name = klass->name();
1637 writer()->write_symbolID(name);
1638
1639 // write a LOAD_CLASS record for the array type (if it exists)
1640 k = klass->array_klass_or_null();
1641 } while (k != NULL);
1642 }
1643
1644 // writes a HPROF_GC_CLASS_DUMP record for the given class
1645 void VM_HeapDumper::do_class_dump(Klass* k) {
1646 if (k->is_instance_klass()) {
1647 DumperSupport::dump_class_and_array_classes(writer(), k);
1648 }
1649 }
1650
1651 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1652 // array (and each multi-dimensional array too)
1653 void VM_HeapDumper::do_basic_type_array_class_dump(Klass* k) {
1654 DumperSupport::dump_basic_type_array_class(writer(), k);
1655 }
1656
1657 // Walk the stack of the given thread.
1658 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
1659 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
1660 //
1661 // It returns the number of Java frames in this thread stack
1662 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
1663 JNILocalsDumper blk(writer(), thread_serial_num);
1664
1665 oop threadObj = java_thread->threadObj();
1666 assert(threadObj != NULL, "sanity check");
1667
1668 int stack_depth = 0;
1669 if (java_thread->has_last_Java_frame()) {
1670
1671 // vframes are resource allocated
1672 Thread* current_thread = Thread::current();
1673 ResourceMark rm(current_thread);
1674 HandleMark hm(current_thread);
1675
1676 RegisterMap reg_map(java_thread);
1677 frame f = java_thread->last_frame();
1678 vframe* vf = vframe::new_vframe(&f, ®_map, java_thread);
1679 frame* last_entry_frame = NULL;
1680 int extra_frames = 0;
1681
1682 if (java_thread == _oome_thread && _oome_constructor != NULL) {
1683 extra_frames++;
1684 }
1685 while (vf != NULL) {
1686 blk.set_frame_number(stack_depth);
1687 if (vf->is_java_frame()) {
1688
1689 // java frame (interpreted, compiled, ...)
1690 javaVFrame *jvf = javaVFrame::cast(vf);
1691 if (!(jvf->method()->is_native())) {
1692 StackValueCollection* locals = jvf->locals();
1693 for (int slot=0; slot<locals->size(); slot++) {
1694 if (locals->at(slot)->type() == T_OBJECT) {
1695 oop o = locals->obj_at(slot)();
1696
1697 if (o != NULL) {
1698 u4 size = 1 + sizeof(address) + 4 + 4;
1699 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
1700 writer()->write_objectID(o);
1701 writer()->write_u4(thread_serial_num);
1702 writer()->write_u4((u4) (stack_depth + extra_frames));
1703 writer()->end_sub_record();
1704 }
1705 }
1706 }
1707 StackValueCollection *exprs = jvf->expressions();
1708 for(int index = 0; index < exprs->size(); index++) {
1709 if (exprs->at(index)->type() == T_OBJECT) {
1710 oop o = exprs->obj_at(index)();
1711 if (o != NULL) {
1712 u4 size = 1 + sizeof(address) + 4 + 4;
1713 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
1714 writer()->write_objectID(o);
1715 writer()->write_u4(thread_serial_num);
1716 writer()->write_u4((u4) (stack_depth + extra_frames));
1717 writer()->end_sub_record();
1718 }
1719 }
1720 }
1721 } else {
1722 // native frame
1723 if (stack_depth == 0) {
1724 // JNI locals for the top frame.
1725 java_thread->active_handles()->oops_do(&blk);
1726 } else {
1727 if (last_entry_frame != NULL) {
1728 // JNI locals for the entry frame
1729 assert(last_entry_frame->is_entry_frame(), "checking");
1730 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
1731 }
1732 }
1733 }
1734 // increment only for Java frames
1735 stack_depth++;
1736 last_entry_frame = NULL;
1737
1738 } else {
1739 // externalVFrame - if it's an entry frame then report any JNI locals
1740 // as roots when we find the corresponding native javaVFrame
1741 frame* fr = vf->frame_pointer();
1742 assert(fr != NULL, "sanity check");
1743 if (fr->is_entry_frame()) {
1744 last_entry_frame = fr;
1745 }
1746 }
1747 vf = vf->sender();
1748 }
1749 } else {
1750 // no last java frame but there may be JNI locals
1751 java_thread->active_handles()->oops_do(&blk);
1752 }
1753 return stack_depth;
1754 }
1755
1756
1757 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
1758 // the stack so that locals and JNI locals are dumped.
1759 void VM_HeapDumper::do_threads() {
1760 for (int i=0; i < _num_threads; i++) {
1761 JavaThread* thread = _stack_traces[i]->thread();
1762 oop threadObj = thread->threadObj();
1763 u4 thread_serial_num = i+1;
1764 u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
1765 u4 size = 1 + sizeof(address) + 4 + 4;
1766 writer()->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
1767 writer()->write_objectID(threadObj);
1768 writer()->write_u4(thread_serial_num); // thread number
1769 writer()->write_u4(stack_serial_num); // stack trace serial number
1770 writer()->end_sub_record();
1771 int num_frames = do_thread(thread, thread_serial_num);
1772 assert(num_frames == _stack_traces[i]->get_stack_depth(),
1773 "total number of Java frames not matched");
1774 }
1775 }
1776
1777
1778 // The VM operation that dumps the heap. The dump consists of the following
1779 // records:
1780 //
1781 // HPROF_HEADER
1782 // [HPROF_UTF8]*
1783 // [HPROF_LOAD_CLASS]*
1784 // [[HPROF_FRAME]*|HPROF_TRACE]*
1785 // [HPROF_GC_CLASS_DUMP]*
1786 // [HPROF_HEAP_DUMP_SEGMENT]*
1787 // HPROF_HEAP_DUMP_END
1788 //
1789 // The HPROF_TRACE records represent the stack traces where the heap dump
1790 // is generated and a "dummy trace" record which does not include
1791 // any frames. The dummy trace record is used to be referenced as the
1792 // unknown object alloc site.
1793 //
1794 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
1795 // To allow the heap dump be generated in a single pass we remember the position
1796 // of the dump length and fix it up after all sub-records have been written.
1797 // To generate the sub-records we iterate over the heap, writing
1798 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
1799 // records as we go. Once that is done we write records for some of the GC
1800 // roots.
1801
1802 void VM_HeapDumper::doit() {
1803
1804 HandleMark hm;
1805 CollectedHeap* ch = Universe::heap();
1806
1807 ch->ensure_parsability(false); // must happen, even if collection does
1808 // not happen (e.g. due to GCLocker)
1809
1810 if (_gc_before_heap_dump) {
1811 if (GCLocker::is_active()) {
1812 warning("GC locker is held; pre-heapdump GC was skipped");
1813 } else {
1814 ch->collect_as_vm_thread(GCCause::_heap_dump);
1815 }
1816 }
1817
1818 // At this point we should be the only dumper active, so
1819 // the following should be safe.
1820 set_global_dumper();
1821 set_global_writer();
1822
1823 // Write the file header - we always use 1.0.2
1824 size_t used = ch->used();
1825 const char* header = "JAVA PROFILE 1.0.2";
1826
1827 // header is few bytes long - no chance to overflow int
1828 writer()->write_raw((void*)header, (int)strlen(header));
1829 writer()->write_u1(0); // terminator
1830 writer()->write_u4(oopSize);
1831 // timestamp is current time in ms
1832 writer()->write_u8(os::javaTimeMillis());
1833
1834 // HPROF_UTF8 records
1835 SymbolTableDumper sym_dumper(writer());
1836 SymbolTable::symbols_do(&sym_dumper);
1837
1838 // write HPROF_LOAD_CLASS records
1839 {
1840 LockedClassesDo locked_load_classes(&do_load_class);
1841 ClassLoaderDataGraph::classes_do(&locked_load_classes);
1842 }
1843 Universe::basic_type_classes_do(&do_load_class);
1844
1845 // write HPROF_FRAME and HPROF_TRACE records
1846 // this must be called after _klass_map is built when iterating the classes above.
1847 dump_stack_traces();
1848
1849 // Writes HPROF_GC_CLASS_DUMP records
1850 {
1851 LockedClassesDo locked_dump_class(&do_class_dump);
1852 ClassLoaderDataGraph::classes_do(&locked_dump_class);
1853 }
1854 Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
1855
1856 // writes HPROF_GC_INSTANCE_DUMP records.
1857 // After each sub-record is written check_segment_length will be invoked
1858 // to check if the current segment exceeds a threshold. If so, a new
1859 // segment is started.
1860 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
1861 // of the heap dump.
1862 HeapObjectDumper obj_dumper(this, writer());
1863 Universe::heap()->object_iterate(&obj_dumper);
1864
1865 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
1866 do_threads();
1867
1868 // HPROF_GC_ROOT_MONITOR_USED
1869 MonitorUsedDumper mon_dumper(writer());
1870 ObjectSynchronizer::oops_do(&mon_dumper);
1871
1872 // HPROF_GC_ROOT_JNI_GLOBAL
1873 JNIGlobalsDumper jni_dumper(writer());
1874 JNIHandles::oops_do(&jni_dumper);
1875 Universe::oops_do(&jni_dumper); // technically not jni roots, but global roots
1876 // for things like preallocated throwable backtraces
1877
1878 // HPROF_GC_ROOT_STICKY_CLASS
1879 // These should be classes in the NULL class loader data, and not all classes
1880 // if !ClassUnloading
1881 StickyClassDumper class_dumper(writer());
1882 ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper);
1883
1884 // Writes the HPROF_HEAP_DUMP_END record.
1885 DumperSupport::end_of_dump(writer());
1886
1887 // Now we clear the global variables, so that a future dumper might run.
1888 clear_global_dumper();
1889 clear_global_writer();
1890 }
1891
1892 void VM_HeapDumper::dump_stack_traces() {
1893 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
1894 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
1895 writer()->write_u4((u4) STACK_TRACE_ID);
1896 writer()->write_u4(0); // thread number
1897 writer()->write_u4(0); // frame count
1898
1899 _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal);
1900 int frame_serial_num = 0;
1901 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1902 oop threadObj = thread->threadObj();
1903 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
1904 // dump thread stack trace
1905 ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
1906 stack_trace->dump_stack_at_safepoint(-1);
1907 _stack_traces[_num_threads++] = stack_trace;
1908
1909 // write HPROF_FRAME records for this thread's stack trace
1910 int depth = stack_trace->get_stack_depth();
1911 int thread_frame_start = frame_serial_num;
1912 int extra_frames = 0;
1913 // write fake frame that makes it look like the thread, which caused OOME,
1914 // is in the OutOfMemoryError zero-parameter constructor
1915 if (thread == _oome_thread && _oome_constructor != NULL) {
1916 int oome_serial_num = _klass_map->find(_oome_constructor->method_holder());
1917 // the class serial number starts from 1
1918 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
1919 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
1920 _oome_constructor, 0);
1921 extra_frames++;
1922 }
1923 for (int j=0; j < depth; j++) {
1924 StackFrameInfo* frame = stack_trace->stack_frame_at(j);
1925 Method* m = frame->method();
1926 int class_serial_num = _klass_map->find(m->method_holder());
1927 // the class serial number starts from 1
1928 assert(class_serial_num > 0, "class not found");
1929 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
1930 }
1931 depth += extra_frames;
1932
1933 // write HPROF_TRACE record for one thread
1934 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
1935 int stack_serial_num = _num_threads + STACK_TRACE_ID;
1936 writer()->write_u4(stack_serial_num); // stack trace serial number
1937 writer()->write_u4((u4) _num_threads); // thread serial number
1938 writer()->write_u4(depth); // frame count
1939 for (int j=1; j <= depth; j++) {
1940 writer()->write_id(thread_frame_start + j);
1941 }
1942 }
1943 }
1944 }
1945
1946 // dump the heap to given path.
1947 int HeapDumper::dump(const char* path, outputStream* out) {
1948 assert(path != NULL && strlen(path) > 0, "path missing");
1949
1950 // print message in interactive case
1951 if (out != NULL) {
1952 out->print_cr("Dumping heap to %s ...", path);
1953 timer()->start();
1954 }
1955
1956 // create JFR event
1957 EventHeapDump event;
1958
1959 // create the dump writer. If the file can be opened then bail
1960 DumpWriter writer(path);
1961 if (writer.error() != NULL) {
1962 set_error(writer.error());
1963 if (out != NULL) {
1964 out->print_cr("Unable to create %s: %s", path,
1965 (error() != NULL) ? error() : "reason unknown");
1966 }
1967 return -1;
1968 }
1969
1970 // generate the dump
1971 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
1972 if (Thread::current()->is_VM_thread()) {
1973 assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
1974 dumper.doit();
1975 } else {
1976 VMThread::execute(&dumper);
1977 }
1978
1979 // close dump file and record any error that the writer may have encountered
1980 writer.close();
1981 set_error(writer.error());
1982
1983 // emit JFR event
1984 if (error() == NULL) {
1985 event.set_destination(path);
1986 event.set_gcBeforeDump(_gc_before_heap_dump);
1987 event.set_size(writer.bytes_written());
1988 event.set_onOutOfMemoryError(_oome);
1989 event.commit();
1990 }
1991
1992 // print message in interactive case
1993 if (out != NULL) {
1994 timer()->stop();
1995 if (error() == NULL) {
1996 out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
1997 writer.bytes_written(), timer()->seconds());
1998 } else {
1999 out->print_cr("Dump file is incomplete: %s", writer.error());
2000 }
2001 }
2002
2003 return (writer.error() == NULL) ? 0 : -1;
2004 }
2005
2006 // stop timer (if still active), and free any error string we might be holding
2007 HeapDumper::~HeapDumper() {
2008 if (timer()->is_active()) {
2009 timer()->stop();
2010 }
2011 set_error(NULL);
2012 }
2013
2014
2015 // returns the error string (resource allocated), or NULL
2016 char* HeapDumper::error_as_C_string() const {
2017 if (error() != NULL) {
2018 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
2019 strcpy(str, error());
2020 return str;
2021 } else {
2022 return NULL;
2023 }
2024 }
2025
2026 // set the error string
2027 void HeapDumper::set_error(char* error) {
2028 if (_error != NULL) {
2029 os::free(_error);
2030 }
2031 if (error == NULL) {
2032 _error = NULL;
2033 } else {
2034 _error = os::strdup(error);
2035 assert(_error != NULL, "allocation failure");
2036 }
2037 }
2038
2039 // Called by out-of-memory error reporting by a single Java thread
2040 // outside of a JVM safepoint
2041 void HeapDumper::dump_heap_from_oome() {
2042 HeapDumper::dump_heap(true);
2043 }
2044
2045 // Called by error reporting by a single Java thread outside of a JVM safepoint,
2046 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
2047 // callers are strictly serialized and guaranteed not to interfere below. For more
2048 // general use, however, this method will need modification to prevent
2049 // inteference when updating the static variables base_path and dump_file_seq below.
2050 void HeapDumper::dump_heap() {
2051 HeapDumper::dump_heap(false);
2052 }
2053
2054 void HeapDumper::dump_heap(bool oome) {
2055 static char base_path[JVM_MAXPATHLEN] = {'\0'};
2056 static uint dump_file_seq = 0;
2057 char* my_path;
2058 const int max_digit_chars = 20;
2059
2060 const char* dump_file_name = "java_pid";
2061 const char* dump_file_ext = ".hprof";
2062
2063 // The dump file defaults to java_pid<pid>.hprof in the current working
2064 // directory. HeapDumpPath=<file> can be used to specify an alternative
2065 // dump file name or a directory where dump file is created.
2066 if (dump_file_seq == 0) { // first time in, we initialize base_path
2067 // Calculate potentially longest base path and check if we have enough
2068 // allocated statically.
2069 const size_t total_length =
2070 (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
2071 strlen(os::file_separator()) + max_digit_chars +
2072 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
2073 if (total_length > sizeof(base_path)) {
2074 warning("Cannot create heap dump file. HeapDumpPath is too long.");
2075 return;
2076 }
2077
2078 bool use_default_filename = true;
2079 if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
2080 // HeapDumpPath=<file> not specified
2081 } else {
2082 strcpy(base_path, HeapDumpPath);
2083 // check if the path is a directory (must exist)
2084 DIR* dir = os::opendir(base_path);
2085 if (dir == NULL) {
2086 use_default_filename = false;
2087 } else {
2088 // HeapDumpPath specified a directory. We append a file separator
2089 // (if needed).
2090 os::closedir(dir);
2091 size_t fs_len = strlen(os::file_separator());
2092 if (strlen(base_path) >= fs_len) {
2093 char* end = base_path;
2094 end += (strlen(base_path) - fs_len);
2095 if (strcmp(end, os::file_separator()) != 0) {
2096 strcat(base_path, os::file_separator());
2097 }
2098 }
2099 }
2100 }
2101 // If HeapDumpPath wasn't a file name then we append the default name
2102 if (use_default_filename) {
2103 const size_t dlen = strlen(base_path); // if heap dump dir specified
2104 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
2105 dump_file_name, os::current_process_id(), dump_file_ext);
2106 }
2107 const size_t len = strlen(base_path) + 1;
2108 my_path = (char*)os::malloc(len, mtInternal);
2109 if (my_path == NULL) {
2110 warning("Cannot create heap dump file. Out of system memory.");
2111 return;
2112 }
2113 strncpy(my_path, base_path, len);
2114 } else {
2115 // Append a sequence number id for dumps following the first
2116 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
2117 my_path = (char*)os::malloc(len, mtInternal);
2118 if (my_path == NULL) {
2119 warning("Cannot create heap dump file. Out of system memory.");
2120 return;
2121 }
2122 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
2123 }
2124 dump_file_seq++; // increment seq number for next time we dump
2125
2126 HeapDumper dumper(false /* no GC before heap dump */,
2127 oome /* pass along out-of-memory-error flag */);
2128 dumper.dump(my_path, tty);
2129 os::free(my_path);
2130 }