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