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