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