1 /*
2 * Copyright (c) 2005, 2015, 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/shared/gcLocker.inline.hpp"
30 #include "gc/shared/genCollectedHeap.hpp"
31 #include "gc/shared/vmGCOperations.hpp"
32 #include "memory/universe.hpp"
33 #include "oops/objArrayKlass.hpp"
34 #include "oops/objArrayOop.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "runtime/javaCalls.hpp"
37 #include "runtime/jniHandles.hpp"
38 #include "runtime/os.hpp"
39 #include "runtime/reflectionUtils.hpp"
40 #include "runtime/vframe.hpp"
41 #include "runtime/vmThread.hpp"
42 #include "runtime/vm_operations.hpp"
43 #include "services/heapDumper.hpp"
44 #include "services/threadService.hpp"
45 #include "utilities/macros.hpp"
46 #include "utilities/ostream.hpp"
47 #if INCLUDE_ALL_GCS
48 #include "gc/parallel/parallelScavengeHeap.hpp"
49 #endif // INCLUDE_ALL_GCS
50
51 /*
52 * HPROF binary format - description copied from:
53 * src/share/demo/jvmti/hprof/hprof_io.c
54 *
55 *
56 * header "JAVA PROFILE 1.0.1" or "JAVA PROFILE 1.0.2"
57 * (0-terminated)
58 *
59 * u4 size of identifiers. Identifiers are used to represent
60 * UTF8 strings, objects, stack traces, etc. They usually
61 * have the same size as host pointers. For example, on
62 * Solaris and Win32, the size is 4.
63 * u4 high word
64 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
65 * [record]* a sequence of records.
66 *
67 *
68 * Record format:
69 *
70 * u1 a TAG denoting the type of the record
71 * u4 number of *microseconds* since the time stamp in the
72 * header. (wraps around in a little more than an hour)
73 * u4 number of bytes *remaining* in the record. Note that
74 * this number excludes the tag and the length field itself.
75 * [u1]* BODY of the record (a sequence of bytes)
76 *
77 *
78 * The following TAGs are supported:
79 *
80 * TAG BODY notes
81 *----------------------------------------------------------
82 * HPROF_UTF8 a UTF8-encoded name
83 *
84 * id name ID
85 * [u1]* UTF8 characters (no trailing zero)
86 *
87 * HPROF_LOAD_CLASS a newly loaded class
88 *
89 * u4 class serial number (> 0)
90 * id class object ID
91 * u4 stack trace serial number
92 * id class name ID
93 *
94 * HPROF_UNLOAD_CLASS an unloading class
95 *
96 * u4 class serial_number
97 *
98 * HPROF_FRAME a Java stack frame
99 *
100 * id stack frame ID
101 * id method name ID
102 * id method signature ID
103 * id source file name ID
104 * u4 class serial number
105 * i4 line number. >0: normal
106 * -1: unknown
107 * -2: compiled method
108 * -3: native method
109 *
110 * HPROF_TRACE a Java stack trace
111 *
112 * u4 stack trace serial number
113 * u4 thread serial number
114 * u4 number of frames
115 * [id]* stack frame IDs
116 *
117 *
118 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
119 *
120 * u2 flags 0x0001: incremental vs. complete
121 * 0x0002: sorted by allocation vs. live
122 * 0x0004: whether to force a GC
123 * u4 cutoff ratio
124 * u4 total live bytes
125 * u4 total live instances
126 * u8 total bytes allocated
127 * u8 total instances allocated
128 * u4 number of sites that follow
129 * [u1 is_array: 0: normal object
130 * 2: object array
131 * 4: boolean array
132 * 5: char array
133 * 6: float array
134 * 7: double array
135 * 8: byte array
136 * 9: short array
137 * 10: int array
138 * 11: long array
139 * u4 class serial number (may be zero during startup)
140 * u4 stack trace serial number
141 * u4 number of bytes alive
142 * u4 number of instances alive
143 * u4 number of bytes allocated
144 * u4]* number of instance allocated
145 *
146 * HPROF_START_THREAD a newly started thread.
147 *
148 * u4 thread serial number (> 0)
149 * id thread object ID
150 * u4 stack trace serial number
151 * id thread name ID
152 * id thread group name ID
153 * id thread group parent name ID
154 *
155 * HPROF_END_THREAD a terminating thread.
156 *
157 * u4 thread serial number
158 *
159 * HPROF_HEAP_SUMMARY heap summary
160 *
161 * u4 total live bytes
162 * u4 total live instances
163 * u8 total bytes allocated
164 * u8 total instances allocated
165 *
166 * HPROF_HEAP_DUMP denote a heap dump
167 *
168 * [heap dump sub-records]*
169 *
170 * There are four kinds of heap dump sub-records:
171 *
172 * u1 sub-record type
173 *
174 * HPROF_GC_ROOT_UNKNOWN unknown root
175 *
176 * id object ID
177 *
178 * HPROF_GC_ROOT_THREAD_OBJ thread object
179 *
180 * id thread object ID (may be 0 for a
181 * thread newly attached through JNI)
182 * u4 thread sequence number
183 * u4 stack trace sequence number
184 *
185 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
186 *
187 * id object ID
188 * id JNI global ref ID
189 *
190 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
191 *
192 * id object ID
193 * u4 thread serial number
194 * u4 frame # in stack trace (-1 for empty)
195 *
196 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
197 *
198 * id object ID
199 * u4 thread serial number
200 * u4 frame # in stack trace (-1 for empty)
201 *
202 * HPROF_GC_ROOT_NATIVE_STACK Native stack
203 *
204 * id object ID
205 * u4 thread serial number
206 *
207 * HPROF_GC_ROOT_STICKY_CLASS System class
208 *
209 * id object ID
210 *
211 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
212 *
213 * id object ID
214 * u4 thread serial number
215 *
216 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
217 *
218 * id object ID
219 *
220 * HPROF_GC_CLASS_DUMP dump of a class object
221 *
222 * id class object ID
223 * u4 stack trace serial number
224 * id super class object ID
225 * id class loader object ID
226 * id signers object ID
227 * id protection domain object ID
228 * id reserved
229 * id reserved
230 *
231 * u4 instance size (in bytes)
232 *
233 * u2 size of constant pool
234 * [u2, constant pool index,
235 * ty, type
236 * 2: object
237 * 4: boolean
238 * 5: char
239 * 6: float
240 * 7: double
241 * 8: byte
242 * 9: short
243 * 10: int
244 * 11: long
245 * vl]* and value
246 *
247 * u2 number of static fields
248 * [id, static field name,
249 * ty, type,
250 * vl]* and value
251 *
252 * u2 number of inst. fields (not inc. super)
253 * [id, instance field name,
254 * ty]* type
255 *
256 * HPROF_GC_INSTANCE_DUMP dump of a normal object
257 *
258 * id object ID
259 * u4 stack trace serial number
260 * id class object ID
261 * u4 number of bytes that follow
262 * [vl]* instance field values (class, followed
263 * by super, super's super ...)
264 *
265 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
266 *
267 * id array object ID
268 * u4 stack trace serial number
269 * u4 number of elements
270 * id array class ID
271 * [id]* elements
272 *
273 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
274 *
275 * id array object ID
276 * u4 stack trace serial number
277 * u4 number of elements
278 * u1 element type
279 * 4: boolean array
280 * 5: char array
281 * 6: float array
282 * 7: double array
283 * 8: byte array
284 * 9: short array
285 * 10: int array
286 * 11: long array
287 * [u1]* elements
288 *
289 * HPROF_CPU_SAMPLES a set of sample traces of running threads
290 *
291 * u4 total number of samples
292 * u4 # of traces
293 * [u4 # of samples
294 * u4]* stack trace serial number
295 *
296 * HPROF_CONTROL_SETTINGS the settings of on/off switches
297 *
298 * u4 0x00000001: alloc traces on/off
299 * 0x00000002: cpu sampling on/off
300 * u2 stack trace depth
301 *
302 *
303 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
304 * be generated as a sequence of heap dump segments. This sequence is
305 * terminated by an end record. The additional tags allowed by format
306 * "JAVA PROFILE 1.0.2" are:
307 *
308 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
309 *
310 * [heap dump sub-records]*
311 * The same sub-record types allowed by HPROF_HEAP_DUMP
312 *
313 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
314 *
315 */
316
317
318 // HPROF tags
319
320 typedef enum {
321 // top-level records
322 HPROF_UTF8 = 0x01,
323 HPROF_LOAD_CLASS = 0x02,
324 HPROF_UNLOAD_CLASS = 0x03,
325 HPROF_FRAME = 0x04,
326 HPROF_TRACE = 0x05,
327 HPROF_ALLOC_SITES = 0x06,
328 HPROF_HEAP_SUMMARY = 0x07,
329 HPROF_START_THREAD = 0x0A,
330 HPROF_END_THREAD = 0x0B,
331 HPROF_HEAP_DUMP = 0x0C,
332 HPROF_CPU_SAMPLES = 0x0D,
333 HPROF_CONTROL_SETTINGS = 0x0E,
334
335 // 1.0.2 record types
336 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
337 HPROF_HEAP_DUMP_END = 0x2C,
338
339 // field types
340 HPROF_ARRAY_OBJECT = 0x01,
341 HPROF_NORMAL_OBJECT = 0x02,
342 HPROF_BOOLEAN = 0x04,
343 HPROF_CHAR = 0x05,
344 HPROF_FLOAT = 0x06,
345 HPROF_DOUBLE = 0x07,
346 HPROF_BYTE = 0x08,
347 HPROF_SHORT = 0x09,
348 HPROF_INT = 0x0A,
349 HPROF_LONG = 0x0B,
350
351 // data-dump sub-records
352 HPROF_GC_ROOT_UNKNOWN = 0xFF,
353 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
354 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
355 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
356 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
357 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
358 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
359 HPROF_GC_ROOT_MONITOR_USED = 0x07,
360 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
361 HPROF_GC_CLASS_DUMP = 0x20,
362 HPROF_GC_INSTANCE_DUMP = 0x21,
363 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
364 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
365 } hprofTag;
366
367 // Default stack trace ID (used for dummy HPROF_TRACE record)
368 enum {
369 STACK_TRACE_ID = 1,
370 INITIAL_CLASS_COUNT = 200
371 };
372
373 // Supports I/O operations on a dump file
374
375 class DumpWriter : public StackObj {
376 private:
377 enum {
378 io_buffer_size = 8*M
379 };
380
381 int _fd; // file descriptor (-1 if dump file not open)
382 jlong _bytes_written; // number of byte written to dump file
383
384 char* _buffer; // internal buffer
385 int _size;
386 int _pos;
387
388 char* _error; // error message when I/O fails
389
390 void set_file_descriptor(int fd) { _fd = fd; }
391 int file_descriptor() const { return _fd; }
392
393 char* buffer() const { return _buffer; }
394 int buffer_size() const { return _size; }
395 int position() const { return _pos; }
396 void set_position(int pos) { _pos = pos; }
397
398 void set_error(const char* error) { _error = (char*)os::strdup(error); }
399
400 // all I/O go through this function
401 void write_internal(void* s, int len);
402
403 public:
404 DumpWriter(const char* path);
405 ~DumpWriter();
406
407 void close();
408 bool is_open() const { return file_descriptor() >= 0; }
409 void flush();
410
411 // total number of bytes written to the disk
412 jlong bytes_written() const { return _bytes_written; }
413
414 // adjust the number of bytes written to disk (used to keep the count
415 // of the number of bytes written in case of rewrites)
416 void adjust_bytes_written(jlong n) { _bytes_written += n; }
417
418 // number of (buffered) bytes as yet unwritten to the dump file
419 jlong bytes_unwritten() const { return (jlong)position(); }
420
421 char* error() const { return _error; }
422
423 jlong current_offset();
424 void seek_to_offset(jlong pos);
425
426 // writer functions
427 void write_raw(void* s, int len);
428 void write_u1(u1 x) { write_raw((void*)&x, 1); }
429 void write_u2(u2 x);
430 void write_u4(u4 x);
431 void write_u8(u8 x);
432 void write_objectID(oop o);
433 void write_symbolID(Symbol* o);
434 void write_classID(Klass* k);
435 void write_id(u4 x);
436 };
437
438 DumpWriter::DumpWriter(const char* path) {
439 // try to allocate an I/O buffer of io_buffer_size. If there isn't
440 // sufficient memory then reduce size until we can allocate something.
441 _size = io_buffer_size;
442 do {
443 _buffer = (char*)os::malloc(_size, mtInternal);
444 if (_buffer == NULL) {
445 _size = _size >> 1;
446 }
447 } while (_buffer == NULL && _size > 0);
448 assert((_size > 0 && _buffer != NULL) || (_size == 0 && _buffer == NULL), "sanity check");
449 _pos = 0;
450 _error = NULL;
451 _bytes_written = 0L;
452 _fd = os::create_binary_file(path, false); // don't replace existing file
453
454 // if the open failed we record the error
455 if (_fd < 0) {
456 _error = (char*)os::strdup(strerror(errno));
457 }
458 }
459
460 DumpWriter::~DumpWriter() {
461 // flush and close dump file
462 if (is_open()) {
463 close();
464 }
465 if (_buffer != NULL) os::free(_buffer);
466 if (_error != NULL) os::free(_error);
467 }
468
469 // closes dump file (if open)
470 void DumpWriter::close() {
471 // flush and close dump file
472 if (is_open()) {
473 flush();
474 ::close(file_descriptor());
475 set_file_descriptor(-1);
476 }
477 }
478
479 // write directly to the file
480 void DumpWriter::write_internal(void* s, int len) {
481 if (is_open()) {
482 int n = ::write(file_descriptor(), s, len);
483 if (n > 0) {
484 _bytes_written += n;
485 }
486 if (n != len) {
487 if (n < 0) {
488 set_error(strerror(errno));
489 } else {
490 set_error("file size limit");
491 }
492 ::close(file_descriptor());
493 set_file_descriptor(-1);
494 }
495 }
496 }
497
498 // write raw bytes
499 void DumpWriter::write_raw(void* s, int len) {
500 if (is_open()) {
501 // flush buffer to make toom
502 if ((position()+ len) >= buffer_size()) {
503 flush();
504 }
505
506 // buffer not available or too big to buffer it
507 if ((buffer() == NULL) || (len >= buffer_size())) {
508 write_internal(s, len);
509 } else {
510 // Should optimize this for u1/u2/u4/u8 sizes.
511 memcpy(buffer() + position(), s, len);
512 set_position(position() + len);
513 }
514 }
515 }
516
517 // flush any buffered bytes to the file
518 void DumpWriter::flush() {
519 if (is_open() && position() > 0) {
520 write_internal(buffer(), position());
521 set_position(0);
522 }
523 }
524
525
526 jlong DumpWriter::current_offset() {
527 if (is_open()) {
528 // the offset is the file offset plus whatever we have buffered
529 jlong offset = os::current_file_offset(file_descriptor());
530 assert(offset >= 0, "lseek failed");
531 return offset + (jlong)position();
532 } else {
533 return (jlong)-1;
534 }
535 }
536
537 void DumpWriter::seek_to_offset(jlong off) {
538 assert(off >= 0, "bad offset");
539
540 // need to flush before seeking
541 flush();
542
543 // may be closed due to I/O error
544 if (is_open()) {
545 jlong n = os::seek_to_file_offset(file_descriptor(), off);
546 assert(n >= 0, "lseek failed");
547 }
548 }
549
550 void DumpWriter::write_u2(u2 x) {
551 u2 v;
552 Bytes::put_Java_u2((address)&v, x);
553 write_raw((void*)&v, 2);
554 }
555
556 void DumpWriter::write_u4(u4 x) {
557 u4 v;
558 Bytes::put_Java_u4((address)&v, x);
559 write_raw((void*)&v, 4);
560 }
561
562 void DumpWriter::write_u8(u8 x) {
563 u8 v;
564 Bytes::put_Java_u8((address)&v, x);
565 write_raw((void*)&v, 8);
566 }
567
568 void DumpWriter::write_objectID(oop o) {
569 address a = (address)o;
570 #ifdef _LP64
571 write_u8((u8)a);
572 #else
573 write_u4((u4)a);
574 #endif
575 }
576
577 void DumpWriter::write_symbolID(Symbol* s) {
578 address a = (address)((uintptr_t)s);
579 #ifdef _LP64
580 write_u8((u8)a);
581 #else
582 write_u4((u4)a);
583 #endif
584 }
585
586 void DumpWriter::write_id(u4 x) {
587 #ifdef _LP64
588 write_u8((u8) x);
589 #else
590 write_u4(x);
591 #endif
592 }
593
594 // We use java mirror as the class ID
595 void DumpWriter::write_classID(Klass* k) {
596 write_objectID(k->java_mirror());
597 }
598
599
600
601 // Support class with a collection of functions used when dumping the heap
602
603 class DumperSupport : AllStatic {
604 public:
605
606 // write a header of the given type
607 static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
608
609 // returns hprof tag for the given type signature
610 static hprofTag sig2tag(Symbol* sig);
611 // returns hprof tag for the given basic type
612 static hprofTag type2tag(BasicType type);
613
614 // returns the size of the instance of the given class
615 static u4 instance_size(Klass* k);
616
617 // dump a jfloat
618 static void dump_float(DumpWriter* writer, jfloat f);
619 // dump a jdouble
620 static void dump_double(DumpWriter* writer, jdouble d);
621 // dumps the raw value of the given field
622 static void dump_field_value(DumpWriter* writer, char type, address addr);
623 // dumps static fields of the given class
624 static void dump_static_fields(DumpWriter* writer, Klass* k);
625 // dump the raw values of the instance fields of the given object
626 static void dump_instance_fields(DumpWriter* writer, oop o);
627 // dumps the definition of the instance fields for a given class
628 static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k);
629 // creates HPROF_GC_INSTANCE_DUMP record for the given object
630 static void dump_instance(DumpWriter* writer, oop o);
631 // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
632 // array classes
633 static void dump_class_and_array_classes(DumpWriter* writer, Klass* k);
634 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
635 // class (and each multi-dimensional array class too)
636 static void dump_basic_type_array_class(DumpWriter* writer, Klass* k);
637
638 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
639 static void dump_object_array(DumpWriter* writer, objArrayOop array);
640 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
641 static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
642 // create HPROF_FRAME record for the given method and bci
643 static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
644 };
645
646 // write a header of the given type
647 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
648 writer->write_u1((u1)tag);
649 writer->write_u4(0); // current ticks
650 writer->write_u4(len);
651 }
652
653 // returns hprof tag for the given type signature
654 hprofTag DumperSupport::sig2tag(Symbol* sig) {
655 switch (sig->byte_at(0)) {
656 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
657 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
658 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
659 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
660 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
661 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
662 case JVM_SIGNATURE_INT : return HPROF_INT;
663 case JVM_SIGNATURE_LONG : return HPROF_LONG;
664 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
665 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
666 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
667 }
668 }
669
670 hprofTag DumperSupport::type2tag(BasicType type) {
671 switch (type) {
672 case T_BYTE : return HPROF_BYTE;
673 case T_CHAR : return HPROF_CHAR;
674 case T_FLOAT : return HPROF_FLOAT;
675 case T_DOUBLE : return HPROF_DOUBLE;
676 case T_INT : return HPROF_INT;
677 case T_LONG : return HPROF_LONG;
678 case T_SHORT : return HPROF_SHORT;
679 case T_BOOLEAN : return HPROF_BOOLEAN;
680 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
681 }
682 }
683
684 // dump a jfloat
685 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
686 if (g_isnan(f)) {
687 writer->write_u4(0x7fc00000); // collapsing NaNs
688 } else {
689 union {
690 int i;
691 float f;
692 } u;
693 u.f = (float)f;
694 writer->write_u4((u4)u.i);
695 }
696 }
697
698 // dump a jdouble
699 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
700 union {
701 jlong l;
702 double d;
703 } u;
704 if (g_isnan(d)) { // collapsing NaNs
705 u.l = (jlong)(0x7ff80000);
706 u.l = (u.l << 32);
707 } else {
708 u.d = (double)d;
709 }
710 writer->write_u8((u8)u.l);
711 }
712
713 // dumps the raw value of the given field
714 void DumperSupport::dump_field_value(DumpWriter* writer, char type, address addr) {
715 switch (type) {
716 case JVM_SIGNATURE_CLASS :
717 case JVM_SIGNATURE_ARRAY : {
718 oop o;
719 if (UseCompressedOops) {
720 o = oopDesc::load_decode_heap_oop((narrowOop*)addr);
721 } else {
722 o = oopDesc::load_decode_heap_oop((oop*)addr);
723 }
724
725 // reflection and Unsafe classes may have a reference to a
726 // Klass* so filter it out.
727 assert(o->is_oop_or_null(), "Expected an oop or NULL at " PTR_FORMAT, p2i(o));
728 writer->write_objectID(o);
729 break;
730 }
731 case JVM_SIGNATURE_BYTE : {
732 jbyte* b = (jbyte*)addr;
733 writer->write_u1((u1)*b);
734 break;
735 }
736 case JVM_SIGNATURE_CHAR : {
737 jchar* c = (jchar*)addr;
738 writer->write_u2((u2)*c);
739 break;
740 }
741 case JVM_SIGNATURE_SHORT : {
742 jshort* s = (jshort*)addr;
743 writer->write_u2((u2)*s);
744 break;
745 }
746 case JVM_SIGNATURE_FLOAT : {
747 jfloat* f = (jfloat*)addr;
748 dump_float(writer, *f);
749 break;
750 }
751 case JVM_SIGNATURE_DOUBLE : {
752 jdouble* f = (jdouble*)addr;
753 dump_double(writer, *f);
754 break;
755 }
756 case JVM_SIGNATURE_INT : {
757 jint* i = (jint*)addr;
758 writer->write_u4((u4)*i);
759 break;
760 }
761 case JVM_SIGNATURE_LONG : {
762 jlong* l = (jlong*)addr;
763 writer->write_u8((u8)*l);
764 break;
765 }
766 case JVM_SIGNATURE_BOOLEAN : {
767 jboolean* b = (jboolean*)addr;
768 writer->write_u1((u1)*b);
769 break;
770 }
771 default : ShouldNotReachHere();
772 }
773 }
774
775 // returns the size of the instance of the given class
776 u4 DumperSupport::instance_size(Klass* k) {
777 HandleMark hm;
778 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
779
780 int size = 0;
781
782 for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
783 if (!fld.access_flags().is_static()) {
784 Symbol* sig = fld.signature();
785 switch (sig->byte_at(0)) {
786 case JVM_SIGNATURE_CLASS :
787 case JVM_SIGNATURE_ARRAY : size += oopSize; break;
788
789 case JVM_SIGNATURE_BYTE :
790 case JVM_SIGNATURE_BOOLEAN : size += 1; break;
791
792 case JVM_SIGNATURE_CHAR :
793 case JVM_SIGNATURE_SHORT : size += 2; break;
794
795 case JVM_SIGNATURE_INT :
796 case JVM_SIGNATURE_FLOAT : size += 4; break;
797
798 case JVM_SIGNATURE_LONG :
799 case JVM_SIGNATURE_DOUBLE : size += 8; break;
800
801 default : ShouldNotReachHere();
802 }
803 }
804 }
805 return (u4)size;
806 }
807
808 // dumps static fields of the given class
809 void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) {
810 HandleMark hm;
811 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
812
813 // pass 1 - count the static fields
814 u2 field_count = 0;
815 for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
816 if (fldc.access_flags().is_static()) field_count++;
817 }
818
819 writer->write_u2(field_count);
820
821 // pass 2 - dump the field descriptors and raw values
822 for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
823 if (fld.access_flags().is_static()) {
824 Symbol* sig = fld.signature();
825
826 writer->write_symbolID(fld.name()); // name
827 writer->write_u1(sig2tag(sig)); // type
828
829 // value
830 int offset = fld.offset();
831 address addr = (address)ikh->java_mirror() + offset;
832
833 dump_field_value(writer, sig->byte_at(0), addr);
834 }
835 }
836 }
837
838 // dump the raw values of the instance fields of the given object
839 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
840 HandleMark hm;
841 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), o->klass());
842
843 for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
844 if (!fld.access_flags().is_static()) {
845 Symbol* sig = fld.signature();
846 address addr = (address)o + fld.offset();
847
848 dump_field_value(writer, sig->byte_at(0), addr);
849 }
850 }
851 }
852
853 // dumps the definition of the instance fields for a given class
854 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) {
855 HandleMark hm;
856 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
857
858 // pass 1 - count the instance fields
859 u2 field_count = 0;
860 for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
861 if (!fldc.access_flags().is_static()) field_count++;
862 }
863
864 writer->write_u2(field_count);
865
866 // pass 2 - dump the field descriptors
867 for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
868 if (!fld.access_flags().is_static()) {
869 Symbol* sig = fld.signature();
870
871 writer->write_symbolID(fld.name()); // name
872 writer->write_u1(sig2tag(sig)); // type
873 }
874 }
875 }
876
877 // creates HPROF_GC_INSTANCE_DUMP record for the given object
878 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
879 Klass* k = o->klass();
880
881 writer->write_u1(HPROF_GC_INSTANCE_DUMP);
882 writer->write_objectID(o);
883 writer->write_u4(STACK_TRACE_ID);
884
885 // class ID
886 writer->write_classID(k);
887
888 // number of bytes that follow
889 writer->write_u4(instance_size(k) );
890
891 // field values
892 dump_instance_fields(writer, o);
893 }
894
895 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
896 // its array classes
897 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
898 InstanceKlass* ik = InstanceKlass::cast(k);
899
900 // We can safepoint and do a heap dump at a point where we have a Klass,
901 // but no java mirror class has been setup for it. So we need to check
902 // that the class is at least loaded, to avoid crash from a null mirror.
903 if (!ik->is_loaded()) {
904 return;
905 }
906
907 writer->write_u1(HPROF_GC_CLASS_DUMP);
908
909 // class ID
910 writer->write_classID(ik);
911 writer->write_u4(STACK_TRACE_ID);
912
913 // super class ID
914 Klass* java_super = ik->java_super();
915 if (java_super == NULL) {
916 writer->write_objectID(oop(NULL));
917 } else {
918 writer->write_classID(java_super);
919 }
920
921 writer->write_objectID(ik->class_loader());
922 writer->write_objectID(ik->signers());
923 writer->write_objectID(ik->protection_domain());
924
925 // reserved
926 writer->write_objectID(oop(NULL));
927 writer->write_objectID(oop(NULL));
928
929 // instance size
930 writer->write_u4(DumperSupport::instance_size(k));
931
932 // size of constant pool - ignored by HAT 1.1
933 writer->write_u2(0);
934
935 // number of static fields
936 dump_static_fields(writer, k);
937
938 // description of instance fields
939 dump_instance_field_descriptors(writer, k);
940
941 // array classes
942 k = k->array_klass_or_null();
943 while (k != NULL) {
944 Klass* klass = k;
945 assert(klass->is_objArray_klass(), "not an ObjArrayKlass");
946
947 writer->write_u1(HPROF_GC_CLASS_DUMP);
948 writer->write_classID(klass);
949 writer->write_u4(STACK_TRACE_ID);
950
951 // super class of array classes is java.lang.Object
952 java_super = klass->java_super();
953 assert(java_super != NULL, "checking");
954 writer->write_classID(java_super);
955
956 writer->write_objectID(ik->class_loader());
957 writer->write_objectID(ik->signers());
958 writer->write_objectID(ik->protection_domain());
959
960 writer->write_objectID(oop(NULL)); // reserved
961 writer->write_objectID(oop(NULL));
962 writer->write_u4(0); // instance size
963 writer->write_u2(0); // constant pool
964 writer->write_u2(0); // static fields
965 writer->write_u2(0); // instance fields
966
967 // get the array class for the next rank
968 k = klass->array_klass_or_null();
969 }
970 }
971
972 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
973 // class (and each multi-dimensional array class too)
974 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) {
975 // array classes
976 while (k != NULL) {
977 Klass* klass = k;
978
979 writer->write_u1(HPROF_GC_CLASS_DUMP);
980 writer->write_classID(klass);
981 writer->write_u4(STACK_TRACE_ID);
982
983 // super class of array classes is java.lang.Object
984 Klass* java_super = klass->java_super();
985 assert(java_super != NULL, "checking");
986 writer->write_classID(java_super);
987
988 writer->write_objectID(oop(NULL)); // loader
989 writer->write_objectID(oop(NULL)); // signers
990 writer->write_objectID(oop(NULL)); // protection domain
991
992 writer->write_objectID(oop(NULL)); // reserved
993 writer->write_objectID(oop(NULL));
994 writer->write_u4(0); // instance size
995 writer->write_u2(0); // constant pool
996 writer->write_u2(0); // static fields
997 writer->write_u2(0); // instance fields
998
999 // get the array class for the next rank
1000 k = klass->array_klass_or_null();
1001 }
1002 }
1003
1004 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1005 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
1006
1007 writer->write_u1(HPROF_GC_OBJ_ARRAY_DUMP);
1008 writer->write_objectID(array);
1009 writer->write_u4(STACK_TRACE_ID);
1010 writer->write_u4((u4)array->length());
1011
1012 // array class ID
1013 writer->write_classID(array->klass());
1014
1015 // [id]* elements
1016 for (int index=0; index<array->length(); index++) {
1017 oop o = array->obj_at(index);
1018 writer->write_objectID(o);
1019 }
1020 }
1021
1022 #define WRITE_ARRAY(Array, Type, Size) \
1023 for (int i=0; i<Array->length(); i++) { writer->write_##Size((Size)array->Type##_at(i)); }
1024
1025
1026 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1027 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
1028 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1029
1030 writer->write_u1(HPROF_GC_PRIM_ARRAY_DUMP);
1031 writer->write_objectID(array);
1032 writer->write_u4(STACK_TRACE_ID);
1033 writer->write_u4((u4)array->length());
1034 writer->write_u1(type2tag(type));
1035
1036 // nothing to copy
1037 if (array->length() == 0) {
1038 return;
1039 }
1040
1041 // If the byte ordering is big endian then we can copy most types directly
1042 int length_in_bytes = array->length() * type2aelembytes(type);
1043 assert(length_in_bytes > 0, "nothing to copy");
1044
1045 switch (type) {
1046 case T_INT : {
1047 if (Bytes::is_Java_byte_ordering_different()) {
1048 WRITE_ARRAY(array, int, u4);
1049 } else {
1050 writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
1051 }
1052 break;
1053 }
1054 case T_BYTE : {
1055 writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
1056 break;
1057 }
1058 case T_CHAR : {
1059 if (Bytes::is_Java_byte_ordering_different()) {
1060 WRITE_ARRAY(array, char, u2);
1061 } else {
1062 writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
1063 }
1064 break;
1065 }
1066 case T_SHORT : {
1067 if (Bytes::is_Java_byte_ordering_different()) {
1068 WRITE_ARRAY(array, short, u2);
1069 } else {
1070 writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
1071 }
1072 break;
1073 }
1074 case T_BOOLEAN : {
1075 if (Bytes::is_Java_byte_ordering_different()) {
1076 WRITE_ARRAY(array, bool, u1);
1077 } else {
1078 writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
1079 }
1080 break;
1081 }
1082 case T_LONG : {
1083 if (Bytes::is_Java_byte_ordering_different()) {
1084 WRITE_ARRAY(array, long, u8);
1085 } else {
1086 writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
1087 }
1088 break;
1089 }
1090
1091 // handle float/doubles in a special value to ensure than NaNs are
1092 // written correctly. TO DO: Check if we can avoid this on processors that
1093 // use IEEE 754.
1094
1095 case T_FLOAT : {
1096 for (int i=0; i<array->length(); i++) {
1097 dump_float( writer, array->float_at(i) );
1098 }
1099 break;
1100 }
1101 case T_DOUBLE : {
1102 for (int i=0; i<array->length(); i++) {
1103 dump_double( writer, array->double_at(i) );
1104 }
1105 break;
1106 }
1107 default : ShouldNotReachHere();
1108 }
1109 }
1110
1111 // create a HPROF_FRAME record of the given Method* and bci
1112 void DumperSupport::dump_stack_frame(DumpWriter* writer,
1113 int frame_serial_num,
1114 int class_serial_num,
1115 Method* m,
1116 int bci) {
1117 int line_number;
1118 if (m->is_native()) {
1119 line_number = -3; // native frame
1120 } else {
1121 line_number = m->line_number_from_bci(bci);
1122 }
1123
1124 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1125 writer->write_id(frame_serial_num); // frame serial number
1126 writer->write_symbolID(m->name()); // method's name
1127 writer->write_symbolID(m->signature()); // method's signature
1128
1129 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1130 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1131 writer->write_u4(class_serial_num); // class serial number
1132 writer->write_u4((u4) line_number); // line number
1133 }
1134
1135
1136 // Support class used to generate HPROF_UTF8 records from the entries in the
1137 // SymbolTable.
1138
1139 class SymbolTableDumper : public SymbolClosure {
1140 private:
1141 DumpWriter* _writer;
1142 DumpWriter* writer() const { return _writer; }
1143 public:
1144 SymbolTableDumper(DumpWriter* writer) { _writer = writer; }
1145 void do_symbol(Symbol** p);
1146 };
1147
1148 void SymbolTableDumper::do_symbol(Symbol** p) {
1149 ResourceMark rm;
1150 Symbol* sym = load_symbol(p);
1151 int len = sym->utf8_length();
1152 if (len > 0) {
1153 char* s = sym->as_utf8();
1154 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1155 writer()->write_symbolID(sym);
1156 writer()->write_raw(s, len);
1157 }
1158 }
1159
1160 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1161
1162 class JNILocalsDumper : public OopClosure {
1163 private:
1164 DumpWriter* _writer;
1165 u4 _thread_serial_num;
1166 int _frame_num;
1167 DumpWriter* writer() const { return _writer; }
1168 public:
1169 JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
1170 _writer = writer;
1171 _thread_serial_num = thread_serial_num;
1172 _frame_num = -1; // default - empty stack
1173 }
1174 void set_frame_number(int n) { _frame_num = n; }
1175 void do_oop(oop* obj_p);
1176 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1177 };
1178
1179
1180 void JNILocalsDumper::do_oop(oop* obj_p) {
1181 // ignore null or deleted handles
1182 oop o = *obj_p;
1183 if (o != NULL && o != JNIHandles::deleted_handle()) {
1184 writer()->write_u1(HPROF_GC_ROOT_JNI_LOCAL);
1185 writer()->write_objectID(o);
1186 writer()->write_u4(_thread_serial_num);
1187 writer()->write_u4((u4)_frame_num);
1188 }
1189 }
1190
1191
1192 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
1193
1194 class JNIGlobalsDumper : public OopClosure {
1195 private:
1196 DumpWriter* _writer;
1197 DumpWriter* writer() const { return _writer; }
1198
1199 public:
1200 JNIGlobalsDumper(DumpWriter* writer) {
1201 _writer = writer;
1202 }
1203 void do_oop(oop* obj_p);
1204 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1205 };
1206
1207 void JNIGlobalsDumper::do_oop(oop* obj_p) {
1208 oop o = *obj_p;
1209
1210 // ignore these
1211 if (o == NULL || o == JNIHandles::deleted_handle()) return;
1212
1213 // we ignore global ref to symbols and other internal objects
1214 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
1215 writer()->write_u1(HPROF_GC_ROOT_JNI_GLOBAL);
1216 writer()->write_objectID(o);
1217 writer()->write_objectID((oopDesc*)obj_p); // global ref ID
1218 }
1219 };
1220
1221
1222 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
1223
1224 class MonitorUsedDumper : public OopClosure {
1225 private:
1226 DumpWriter* _writer;
1227 DumpWriter* writer() const { return _writer; }
1228 public:
1229 MonitorUsedDumper(DumpWriter* writer) {
1230 _writer = writer;
1231 }
1232 void do_oop(oop* obj_p) {
1233 writer()->write_u1(HPROF_GC_ROOT_MONITOR_USED);
1234 writer()->write_objectID(*obj_p);
1235 }
1236 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1237 };
1238
1239
1240 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
1241
1242 class StickyClassDumper : public KlassClosure {
1243 private:
1244 DumpWriter* _writer;
1245 DumpWriter* writer() const { return _writer; }
1246 public:
1247 StickyClassDumper(DumpWriter* writer) {
1248 _writer = writer;
1249 }
1250 void do_klass(Klass* k) {
1251 if (k->is_instance_klass()) {
1252 InstanceKlass* ik = InstanceKlass::cast(k);
1253 writer()->write_u1(HPROF_GC_ROOT_STICKY_CLASS);
1254 writer()->write_classID(ik);
1255 }
1256 }
1257 };
1258
1259
1260 class VM_HeapDumper;
1261
1262 // Support class using when iterating over the heap.
1263
1264 class HeapObjectDumper : public ObjectClosure {
1265 private:
1266 VM_HeapDumper* _dumper;
1267 DumpWriter* _writer;
1268
1269 VM_HeapDumper* dumper() { return _dumper; }
1270 DumpWriter* writer() { return _writer; }
1271
1272 // used to indicate that a record has been writen
1273 void mark_end_of_record();
1274
1275 public:
1276 HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
1277 _dumper = dumper;
1278 _writer = writer;
1279 }
1280
1281 // called for each object in the heap
1282 void do_object(oop o);
1283 };
1284
1285 void HeapObjectDumper::do_object(oop o) {
1286 // hide the sentinel for deleted handles
1287 if (o == JNIHandles::deleted_handle()) return;
1288
1289 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
1290 if (o->klass() == SystemDictionary::Class_klass()) {
1291 if (!java_lang_Class::is_primitive(o)) {
1292 return;
1293 }
1294 }
1295
1296 // create a HPROF_GC_INSTANCE record for each object
1297 if (o->is_instance()) {
1298 DumperSupport::dump_instance(writer(), o);
1299 mark_end_of_record();
1300 } else {
1301 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
1302 if (o->is_objArray()) {
1303 DumperSupport::dump_object_array(writer(), objArrayOop(o));
1304 mark_end_of_record();
1305 } else {
1306 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
1307 if (o->is_typeArray()) {
1308 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
1309 mark_end_of_record();
1310 }
1311 }
1312 }
1313 }
1314
1315 // The VM operation that performs the heap dump
1316 class VM_HeapDumper : public VM_GC_Operation {
1317 private:
1318 static VM_HeapDumper* _global_dumper;
1319 static DumpWriter* _global_writer;
1320 DumpWriter* _local_writer;
1321 JavaThread* _oome_thread;
1322 Method* _oome_constructor;
1323 bool _gc_before_heap_dump;
1324 bool _is_segmented_dump;
1325 jlong _dump_start;
1326 GrowableArray<Klass*>* _klass_map;
1327 ThreadStackTrace** _stack_traces;
1328 int _num_threads;
1329
1330 // accessors and setters
1331 static VM_HeapDumper* dumper() { assert(_global_dumper != NULL, "Error"); return _global_dumper; }
1332 static DumpWriter* writer() { assert(_global_writer != NULL, "Error"); return _global_writer; }
1333 void set_global_dumper() {
1334 assert(_global_dumper == NULL, "Error");
1335 _global_dumper = this;
1336 }
1337 void set_global_writer() {
1338 assert(_global_writer == NULL, "Error");
1339 _global_writer = _local_writer;
1340 }
1341 void clear_global_dumper() { _global_dumper = NULL; }
1342 void clear_global_writer() { _global_writer = NULL; }
1343
1344 bool is_segmented_dump() const { return _is_segmented_dump; }
1345 void set_segmented_dump() { _is_segmented_dump = true; }
1346 jlong dump_start() const { return _dump_start; }
1347 void set_dump_start(jlong pos);
1348
1349 bool skip_operation() const;
1350
1351 // writes a HPROF_LOAD_CLASS record
1352 static void do_load_class(Klass* k);
1353
1354 // writes a HPROF_GC_CLASS_DUMP record for the given class
1355 // (and each array class too)
1356 static void do_class_dump(Klass* k);
1357
1358 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1359 // array (and each multi-dimensional array too)
1360 static void do_basic_type_array_class_dump(Klass* k);
1361
1362 // HPROF_GC_ROOT_THREAD_OBJ records
1363 int do_thread(JavaThread* thread, u4 thread_serial_num);
1364 void do_threads();
1365
1366 void add_class_serial_number(Klass* k, int serial_num) {
1367 _klass_map->at_put_grow(serial_num, k);
1368 }
1369
1370 // HPROF_TRACE and HPROF_FRAME records
1371 void dump_stack_traces();
1372
1373 // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
1374 void write_dump_header();
1375
1376 // fixes up the length of the current dump record
1377 void write_current_dump_record_length();
1378
1379 // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
1380 // record in the case of a segmented heap dump)
1381 void end_of_dump();
1382
1383 public:
1384 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
1385 VM_GC_Operation(0 /* total collections, dummy, ignored */,
1386 GCCause::_heap_dump /* GC Cause */,
1387 0 /* total full collections, dummy, ignored */,
1388 gc_before_heap_dump) {
1389 _local_writer = writer;
1390 _gc_before_heap_dump = gc_before_heap_dump;
1391 _is_segmented_dump = false;
1392 _dump_start = (jlong)-1;
1393 _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
1394 _stack_traces = NULL;
1395 _num_threads = 0;
1396 if (oome) {
1397 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
1398 // get OutOfMemoryError zero-parameter constructor
1399 InstanceKlass* oome_ik = SystemDictionary::OutOfMemoryError_klass();
1400 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
1401 vmSymbols::void_method_signature());
1402 // get thread throwing OOME when generating the heap dump at OOME
1403 _oome_thread = JavaThread::current();
1404 } else {
1405 _oome_thread = NULL;
1406 _oome_constructor = NULL;
1407 }
1408 }
1409 ~VM_HeapDumper() {
1410 if (_stack_traces != NULL) {
1411 for (int i=0; i < _num_threads; i++) {
1412 delete _stack_traces[i];
1413 }
1414 FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces);
1415 }
1416 delete _klass_map;
1417 }
1418
1419 VMOp_Type type() const { return VMOp_HeapDumper; }
1420 // used to mark sub-record boundary
1421 void check_segment_length();
1422 void doit();
1423 };
1424
1425 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
1426 DumpWriter* VM_HeapDumper::_global_writer = NULL;
1427
1428 bool VM_HeapDumper::skip_operation() const {
1429 return false;
1430 }
1431
1432 // sets the dump starting position
1433 void VM_HeapDumper::set_dump_start(jlong pos) {
1434 _dump_start = pos;
1435 }
1436
1437 // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
1438 void VM_HeapDumper::write_dump_header() {
1439 if (writer()->is_open()) {
1440 if (is_segmented_dump()) {
1441 writer()->write_u1(HPROF_HEAP_DUMP_SEGMENT);
1442 } else {
1443 writer()->write_u1(HPROF_HEAP_DUMP);
1444 }
1445 writer()->write_u4(0); // current ticks
1446
1447 // record the starting position for the dump (its length will be fixed up later)
1448 set_dump_start(writer()->current_offset());
1449 writer()->write_u4(0);
1450 }
1451 }
1452
1453 // fixes up the length of the current dump record
1454 void VM_HeapDumper::write_current_dump_record_length() {
1455 if (writer()->is_open()) {
1456 assert(dump_start() >= 0, "no dump start recorded");
1457
1458 // calculate the size of the dump record
1459 jlong dump_end = writer()->current_offset();
1460 jlong dump_len = (dump_end - dump_start() - 4);
1461
1462 // record length must fit in a u4
1463 if (dump_len > (jlong)(4L*(jlong)G)) {
1464 warning("record is too large");
1465 }
1466
1467 // seek to the dump start and fix-up the length
1468 writer()->seek_to_offset(dump_start());
1469 writer()->write_u4((u4)dump_len);
1470
1471 // adjust the total size written to keep the bytes written correct.
1472 writer()->adjust_bytes_written(-((long) sizeof(u4)));
1473
1474 // seek to dump end so we can continue
1475 writer()->seek_to_offset(dump_end);
1476
1477 // no current dump record
1478 set_dump_start((jlong)-1);
1479 }
1480 }
1481
1482 // used on a sub-record boundary to check if we need to start a
1483 // new segment.
1484 void VM_HeapDumper::check_segment_length() {
1485 if (writer()->is_open()) {
1486 if (is_segmented_dump()) {
1487 // don't use current_offset that would be too expensive on a per record basis
1488 jlong dump_end = writer()->bytes_written() + writer()->bytes_unwritten();
1489 assert(dump_end == writer()->current_offset(), "checking");
1490 jlong dump_len = (dump_end - dump_start() - 4);
1491 assert(dump_len >= 0 && dump_len <= max_juint, "bad dump length");
1492
1493 if (dump_len > (jlong)HeapDumpSegmentSize) {
1494 write_current_dump_record_length();
1495 write_dump_header();
1496 }
1497 }
1498 }
1499 }
1500
1501 // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
1502 // record in the case of a segmented heap dump)
1503 void VM_HeapDumper::end_of_dump() {
1504 if (writer()->is_open()) {
1505 write_current_dump_record_length();
1506
1507 // for segmented dump we write the end record
1508 if (is_segmented_dump()) {
1509 writer()->write_u1(HPROF_HEAP_DUMP_END);
1510 writer()->write_u4(0);
1511 writer()->write_u4(0);
1512 }
1513 }
1514 }
1515
1516 // marks sub-record boundary
1517 void HeapObjectDumper::mark_end_of_record() {
1518 dumper()->check_segment_length();
1519 }
1520
1521 // writes a HPROF_LOAD_CLASS record for the class (and each of its
1522 // array classes)
1523 void VM_HeapDumper::do_load_class(Klass* k) {
1524 static u4 class_serial_num = 0;
1525
1526 // len of HPROF_LOAD_CLASS record
1527 u4 remaining = 2*oopSize + 2*sizeof(u4);
1528
1529 // write a HPROF_LOAD_CLASS for the class and each array class
1530 do {
1531 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
1532
1533 // class serial number is just a number
1534 writer()->write_u4(++class_serial_num);
1535
1536 // class ID
1537 Klass* klass = k;
1538 writer()->write_classID(klass);
1539
1540 // add the Klass* and class serial number pair
1541 dumper()->add_class_serial_number(klass, class_serial_num);
1542
1543 writer()->write_u4(STACK_TRACE_ID);
1544
1545 // class name ID
1546 Symbol* name = klass->name();
1547 writer()->write_symbolID(name);
1548
1549 // write a LOAD_CLASS record for the array type (if it exists)
1550 k = klass->array_klass_or_null();
1551 } while (k != NULL);
1552 }
1553
1554 // writes a HPROF_GC_CLASS_DUMP record for the given class
1555 void VM_HeapDumper::do_class_dump(Klass* k) {
1556 if (k->is_instance_klass()) {
1557 DumperSupport::dump_class_and_array_classes(writer(), k);
1558 }
1559 }
1560
1561 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1562 // array (and each multi-dimensional array too)
1563 void VM_HeapDumper::do_basic_type_array_class_dump(Klass* k) {
1564 DumperSupport::dump_basic_type_array_class(writer(), k);
1565 }
1566
1567 // Walk the stack of the given thread.
1568 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
1569 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
1570 //
1571 // It returns the number of Java frames in this thread stack
1572 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
1573 JNILocalsDumper blk(writer(), thread_serial_num);
1574
1575 oop threadObj = java_thread->threadObj();
1576 assert(threadObj != NULL, "sanity check");
1577
1578 int stack_depth = 0;
1579 if (java_thread->has_last_Java_frame()) {
1580
1581 // vframes are resource allocated
1582 Thread* current_thread = Thread::current();
1583 ResourceMark rm(current_thread);
1584 HandleMark hm(current_thread);
1585
1586 RegisterMap reg_map(java_thread);
1587 frame f = java_thread->last_frame();
1588 vframe* vf = vframe::new_vframe(&f, ®_map, java_thread);
1589 frame* last_entry_frame = NULL;
1590 int extra_frames = 0;
1591
1592 if (java_thread == _oome_thread && _oome_constructor != NULL) {
1593 extra_frames++;
1594 }
1595 while (vf != NULL) {
1596 blk.set_frame_number(stack_depth);
1597 if (vf->is_java_frame()) {
1598
1599 // java frame (interpreted, compiled, ...)
1600 javaVFrame *jvf = javaVFrame::cast(vf);
1601 if (!(jvf->method()->is_native())) {
1602 StackValueCollection* locals = jvf->locals();
1603 for (int slot=0; slot<locals->size(); slot++) {
1604 if (locals->at(slot)->type() == T_OBJECT) {
1605 oop o = locals->obj_at(slot)();
1606
1607 if (o != NULL) {
1608 writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME);
1609 writer()->write_objectID(o);
1610 writer()->write_u4(thread_serial_num);
1611 writer()->write_u4((u4) (stack_depth + extra_frames));
1612 }
1613 }
1614 }
1615 StackValueCollection *exprs = jvf->expressions();
1616 for(int index = 0; index < exprs->size(); index++) {
1617 if (exprs->at(index)->type() == T_OBJECT) {
1618 oop o = exprs->obj_at(index)();
1619 if (o != NULL) {
1620 writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME);
1621 writer()->write_objectID(o);
1622 writer()->write_u4(thread_serial_num);
1623 writer()->write_u4((u4) (stack_depth + extra_frames));
1624 }
1625 }
1626 }
1627 } else {
1628 // native frame
1629 if (stack_depth == 0) {
1630 // JNI locals for the top frame.
1631 java_thread->active_handles()->oops_do(&blk);
1632 } else {
1633 if (last_entry_frame != NULL) {
1634 // JNI locals for the entry frame
1635 assert(last_entry_frame->is_entry_frame(), "checking");
1636 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
1637 }
1638 }
1639 }
1640 // increment only for Java frames
1641 stack_depth++;
1642 last_entry_frame = NULL;
1643
1644 } else {
1645 // externalVFrame - if it's an entry frame then report any JNI locals
1646 // as roots when we find the corresponding native javaVFrame
1647 frame* fr = vf->frame_pointer();
1648 assert(fr != NULL, "sanity check");
1649 if (fr->is_entry_frame()) {
1650 last_entry_frame = fr;
1651 }
1652 }
1653 vf = vf->sender();
1654 }
1655 } else {
1656 // no last java frame but there may be JNI locals
1657 java_thread->active_handles()->oops_do(&blk);
1658 }
1659 return stack_depth;
1660 }
1661
1662
1663 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
1664 // the stack so that locals and JNI locals are dumped.
1665 void VM_HeapDumper::do_threads() {
1666 for (int i=0; i < _num_threads; i++) {
1667 JavaThread* thread = _stack_traces[i]->thread();
1668 oop threadObj = thread->threadObj();
1669 u4 thread_serial_num = i+1;
1670 u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
1671 writer()->write_u1(HPROF_GC_ROOT_THREAD_OBJ);
1672 writer()->write_objectID(threadObj);
1673 writer()->write_u4(thread_serial_num); // thread number
1674 writer()->write_u4(stack_serial_num); // stack trace serial number
1675 int num_frames = do_thread(thread, thread_serial_num);
1676 assert(num_frames == _stack_traces[i]->get_stack_depth(),
1677 "total number of Java frames not matched");
1678 }
1679 }
1680
1681
1682 // The VM operation that dumps the heap. The dump consists of the following
1683 // records:
1684 //
1685 // HPROF_HEADER
1686 // [HPROF_UTF8]*
1687 // [HPROF_LOAD_CLASS]*
1688 // [[HPROF_FRAME]*|HPROF_TRACE]*
1689 // [HPROF_GC_CLASS_DUMP]*
1690 // HPROF_HEAP_DUMP
1691 //
1692 // The HPROF_TRACE records represent the stack traces where the heap dump
1693 // is generated and a "dummy trace" record which does not include
1694 // any frames. The dummy trace record is used to be referenced as the
1695 // unknown object alloc site.
1696 //
1697 // The HPROF_HEAP_DUMP record has a length following by sub-records. To allow
1698 // the heap dump be generated in a single pass we remember the position of
1699 // the dump length and fix it up after all sub-records have been written.
1700 // To generate the sub-records we iterate over the heap, writing
1701 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
1702 // records as we go. Once that is done we write records for some of the GC
1703 // roots.
1704
1705 void VM_HeapDumper::doit() {
1706
1707 HandleMark hm;
1708 CollectedHeap* ch = Universe::heap();
1709
1710 ch->ensure_parsability(false); // must happen, even if collection does
1711 // not happen (e.g. due to GC_locker)
1712
1713 if (_gc_before_heap_dump) {
1714 if (GC_locker::is_active()) {
1715 warning("GC locker is held; pre-heapdump GC was skipped");
1716 } else {
1717 ch->collect_as_vm_thread(GCCause::_heap_dump);
1718 }
1719 }
1720
1721 // At this point we should be the only dumper active, so
1722 // the following should be safe.
1723 set_global_dumper();
1724 set_global_writer();
1725
1726 // Write the file header - use 1.0.2 for large heaps, otherwise 1.0.1
1727 size_t used = ch->used();
1728 const char* header;
1729 if (used > SegmentedHeapDumpThreshold) {
1730 set_segmented_dump();
1731 header = "JAVA PROFILE 1.0.2";
1732 } else {
1733 header = "JAVA PROFILE 1.0.1";
1734 }
1735
1736 // header is few bytes long - no chance to overflow int
1737 writer()->write_raw((void*)header, (int)strlen(header));
1738 writer()->write_u1(0); // terminator
1739 writer()->write_u4(oopSize);
1740 writer()->write_u8(os::javaTimeMillis());
1741
1742 // HPROF_UTF8 records
1743 SymbolTableDumper sym_dumper(writer());
1744 SymbolTable::symbols_do(&sym_dumper);
1745
1746 // write HPROF_LOAD_CLASS records
1747 ClassLoaderDataGraph::classes_do(&do_load_class);
1748 Universe::basic_type_classes_do(&do_load_class);
1749
1750 // write HPROF_FRAME and HPROF_TRACE records
1751 // this must be called after _klass_map is built when iterating the classes above.
1752 dump_stack_traces();
1753
1754 // write HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT
1755 write_dump_header();
1756
1757 // Writes HPROF_GC_CLASS_DUMP records
1758 ClassLoaderDataGraph::classes_do(&do_class_dump);
1759 Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
1760 check_segment_length();
1761
1762 // writes HPROF_GC_INSTANCE_DUMP records.
1763 // After each sub-record is written check_segment_length will be invoked. When
1764 // generated a segmented heap dump this allows us to check if the current
1765 // segment exceeds a threshold and if so, then a new segment is started.
1766 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
1767 // of the heap dump.
1768 HeapObjectDumper obj_dumper(this, writer());
1769 Universe::heap()->safe_object_iterate(&obj_dumper);
1770
1771 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
1772 do_threads();
1773 check_segment_length();
1774
1775 // HPROF_GC_ROOT_MONITOR_USED
1776 MonitorUsedDumper mon_dumper(writer());
1777 ObjectSynchronizer::oops_do(&mon_dumper);
1778 check_segment_length();
1779
1780 // HPROF_GC_ROOT_JNI_GLOBAL
1781 JNIGlobalsDumper jni_dumper(writer());
1782 JNIHandles::oops_do(&jni_dumper);
1783 check_segment_length();
1784
1785 // HPROF_GC_ROOT_STICKY_CLASS
1786 StickyClassDumper class_dumper(writer());
1787 SystemDictionary::always_strong_classes_do(&class_dumper);
1788
1789 // fixes up the length of the dump record. In the case of a segmented
1790 // heap then the HPROF_HEAP_DUMP_END record is also written.
1791 end_of_dump();
1792
1793 // Now we clear the global variables, so that a future dumper might run.
1794 clear_global_dumper();
1795 clear_global_writer();
1796 }
1797
1798 void VM_HeapDumper::dump_stack_traces() {
1799 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
1800 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
1801 writer()->write_u4((u4) STACK_TRACE_ID);
1802 writer()->write_u4(0); // thread number
1803 writer()->write_u4(0); // frame count
1804
1805 _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal);
1806 int frame_serial_num = 0;
1807 for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) {
1808 oop threadObj = thread->threadObj();
1809 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
1810 // dump thread stack trace
1811 ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
1812 stack_trace->dump_stack_at_safepoint(-1);
1813 _stack_traces[_num_threads++] = stack_trace;
1814
1815 // write HPROF_FRAME records for this thread's stack trace
1816 int depth = stack_trace->get_stack_depth();
1817 int thread_frame_start = frame_serial_num;
1818 int extra_frames = 0;
1819 // write fake frame that makes it look like the thread, which caused OOME,
1820 // is in the OutOfMemoryError zero-parameter constructor
1821 if (thread == _oome_thread && _oome_constructor != NULL) {
1822 int oome_serial_num = _klass_map->find(_oome_constructor->method_holder());
1823 // the class serial number starts from 1
1824 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
1825 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
1826 _oome_constructor, 0);
1827 extra_frames++;
1828 }
1829 for (int j=0; j < depth; j++) {
1830 StackFrameInfo* frame = stack_trace->stack_frame_at(j);
1831 Method* m = frame->method();
1832 int class_serial_num = _klass_map->find(m->method_holder());
1833 // the class serial number starts from 1
1834 assert(class_serial_num > 0, "class not found");
1835 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
1836 }
1837 depth += extra_frames;
1838
1839 // write HPROF_TRACE record for one thread
1840 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
1841 int stack_serial_num = _num_threads + STACK_TRACE_ID;
1842 writer()->write_u4(stack_serial_num); // stack trace serial number
1843 writer()->write_u4((u4) _num_threads); // thread serial number
1844 writer()->write_u4(depth); // frame count
1845 for (int j=1; j <= depth; j++) {
1846 writer()->write_id(thread_frame_start + j);
1847 }
1848 }
1849 }
1850 }
1851
1852 // dump the heap to given path.
1853 int HeapDumper::dump(const char* path) {
1854 assert(path != NULL && strlen(path) > 0, "path missing");
1855
1856 // print message in interactive case
1857 if (print_to_tty()) {
1858 tty->print_cr("Dumping heap to %s ...", path);
1859 timer()->start();
1860 }
1861
1862 // create the dump writer. If the file can be opened then bail
1863 DumpWriter writer(path);
1864 if (!writer.is_open()) {
1865 set_error(writer.error());
1866 if (print_to_tty()) {
1867 tty->print_cr("Unable to create %s: %s", path,
1868 (error() != NULL) ? error() : "reason unknown");
1869 }
1870 return -1;
1871 }
1872
1873 // generate the dump
1874 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
1875 if (Thread::current()->is_VM_thread()) {
1876 assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
1877 dumper.doit();
1878 } else {
1879 VMThread::execute(&dumper);
1880 }
1881
1882 // close dump file and record any error that the writer may have encountered
1883 writer.close();
1884 set_error(writer.error());
1885
1886 // print message in interactive case
1887 if (print_to_tty()) {
1888 timer()->stop();
1889 if (error() == NULL) {
1890 tty->print_cr("Heap dump file created [" JLONG_FORMAT " bytes in %3.3f secs]",
1891 writer.bytes_written(), timer()->seconds());
1892 } else {
1893 tty->print_cr("Dump file is incomplete: %s", writer.error());
1894 }
1895 }
1896
1897 return (writer.error() == NULL) ? 0 : -1;
1898 }
1899
1900 // stop timer (if still active), and free any error string we might be holding
1901 HeapDumper::~HeapDumper() {
1902 if (timer()->is_active()) {
1903 timer()->stop();
1904 }
1905 set_error(NULL);
1906 }
1907
1908
1909 // returns the error string (resource allocated), or NULL
1910 char* HeapDumper::error_as_C_string() const {
1911 if (error() != NULL) {
1912 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
1913 strcpy(str, error());
1914 return str;
1915 } else {
1916 return NULL;
1917 }
1918 }
1919
1920 // set the error string
1921 void HeapDumper::set_error(char* error) {
1922 if (_error != NULL) {
1923 os::free(_error);
1924 }
1925 if (error == NULL) {
1926 _error = NULL;
1927 } else {
1928 _error = os::strdup(error);
1929 assert(_error != NULL, "allocation failure");
1930 }
1931 }
1932
1933 // Called by out-of-memory error reporting by a single Java thread
1934 // outside of a JVM safepoint
1935 void HeapDumper::dump_heap_from_oome() {
1936 HeapDumper::dump_heap(true);
1937 }
1938
1939 // Called by error reporting by a single Java thread outside of a JVM safepoint,
1940 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
1941 // callers are strictly serialized and guaranteed not to interfere below. For more
1942 // general use, however, this method will need modification to prevent
1943 // inteference when updating the static variables base_path and dump_file_seq below.
1944 void HeapDumper::dump_heap() {
1945 HeapDumper::dump_heap(false);
1946 }
1947
1948 void HeapDumper::dump_heap(bool oome) {
1949 static char base_path[JVM_MAXPATHLEN] = {'\0'};
1950 static uint dump_file_seq = 0;
1951 char* my_path;
1952 const int max_digit_chars = 20;
1953
1954 const char* dump_file_name = "java_pid";
1955 const char* dump_file_ext = ".hprof";
1956
1957 // The dump file defaults to java_pid<pid>.hprof in the current working
1958 // directory. HeapDumpPath=<file> can be used to specify an alternative
1959 // dump file name or a directory where dump file is created.
1960 if (dump_file_seq == 0) { // first time in, we initialize base_path
1961 // Calculate potentially longest base path and check if we have enough
1962 // allocated statically.
1963 const size_t total_length =
1964 (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
1965 strlen(os::file_separator()) + max_digit_chars +
1966 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
1967 if (total_length > sizeof(base_path)) {
1968 warning("Cannot create heap dump file. HeapDumpPath is too long.");
1969 return;
1970 }
1971
1972 bool use_default_filename = true;
1973 if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
1974 // HeapDumpPath=<file> not specified
1975 } else {
1976 strcpy(base_path, HeapDumpPath);
1977 // check if the path is a directory (must exist)
1978 DIR* dir = os::opendir(base_path);
1979 if (dir == NULL) {
1980 use_default_filename = false;
1981 } else {
1982 // HeapDumpPath specified a directory. We append a file separator
1983 // (if needed).
1984 os::closedir(dir);
1985 size_t fs_len = strlen(os::file_separator());
1986 if (strlen(base_path) >= fs_len) {
1987 char* end = base_path;
1988 end += (strlen(base_path) - fs_len);
1989 if (strcmp(end, os::file_separator()) != 0) {
1990 strcat(base_path, os::file_separator());
1991 }
1992 }
1993 }
1994 }
1995 // If HeapDumpPath wasn't a file name then we append the default name
1996 if (use_default_filename) {
1997 const size_t dlen = strlen(base_path); // if heap dump dir specified
1998 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
1999 dump_file_name, os::current_process_id(), dump_file_ext);
2000 }
2001 const size_t len = strlen(base_path) + 1;
2002 my_path = (char*)os::malloc(len, mtInternal);
2003 if (my_path == NULL) {
2004 warning("Cannot create heap dump file. Out of system memory.");
2005 return;
2006 }
2007 strncpy(my_path, base_path, len);
2008 } else {
2009 // Append a sequence number id for dumps following the first
2010 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
2011 my_path = (char*)os::malloc(len, mtInternal);
2012 if (my_path == NULL) {
2013 warning("Cannot create heap dump file. Out of system memory.");
2014 return;
2015 }
2016 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
2017 }
2018 dump_file_seq++; // increment seq number for next time we dump
2019
2020 HeapDumper dumper(false /* no GC before heap dump */,
2021 true /* send to tty */,
2022 oome /* pass along out-of-memory-error flag */);
2023 dumper.dump(my_path);
2024 os::free(my_path);
2025 }