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