Fri, 14 Jan 2011 13:47:53 -0500
6811367: Fix code in HeapDumper::dump_heap() to avoid buffer overrun
Summary: Check buffer size before using and use dynamic buffer sizes for subsequent calls.
Reviewed-by: kamg, dholmes
1 /*
2 * Copyright (c) 2005, 2010, 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 */
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/genCollectedHeap.hpp"
31 #include "memory/universe.hpp"
32 #include "oops/objArrayKlass.hpp"
33 #include "runtime/javaCalls.hpp"
34 #include "runtime/jniHandles.hpp"
35 #include "runtime/reflectionUtils.hpp"
36 #include "runtime/vframe.hpp"
37 #include "runtime/vmThread.hpp"
38 #include "runtime/vm_operations.hpp"
39 #include "services/heapDumper.hpp"
40 #include "services/threadService.hpp"
41 #include "utilities/ostream.hpp"
42 #ifndef SERIALGC
43 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
44 #endif
46 /*
47 * HPROF binary format - description copied from:
48 * src/share/demo/jvmti/hprof/hprof_io.c
49 *
50 *
51 * header "JAVA PROFILE 1.0.1" or "JAVA PROFILE 1.0.2"
52 * (0-terminated)
53 *
54 * u4 size of identifiers. Identifiers are used to represent
55 * UTF8 strings, objects, stack traces, etc. They usually
56 * have the same size as host pointers. For example, on
57 * Solaris and Win32, the size is 4.
58 * u4 high word
59 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
60 * [record]* a sequence of records.
61 *
62 *
63 * Record format:
64 *
65 * u1 a TAG denoting the type of the record
66 * u4 number of *microseconds* since the time stamp in the
67 * header. (wraps around in a little more than an hour)
68 * u4 number of bytes *remaining* in the record. Note that
69 * this number excludes the tag and the length field itself.
70 * [u1]* BODY of the record (a sequence of bytes)
71 *
72 *
73 * The following TAGs are supported:
74 *
75 * TAG BODY notes
76 *----------------------------------------------------------
77 * HPROF_UTF8 a UTF8-encoded name
78 *
79 * id name ID
80 * [u1]* UTF8 characters (no trailing zero)
81 *
82 * HPROF_LOAD_CLASS a newly loaded class
83 *
84 * u4 class serial number (> 0)
85 * id class object ID
86 * u4 stack trace serial number
87 * id class name ID
88 *
89 * HPROF_UNLOAD_CLASS an unloading class
90 *
91 * u4 class serial_number
92 *
93 * HPROF_FRAME a Java stack frame
94 *
95 * id stack frame ID
96 * id method name ID
97 * id method signature ID
98 * id source file name ID
99 * u4 class serial number
100 * i4 line number. >0: normal
101 * -1: unknown
102 * -2: compiled method
103 * -3: native method
104 *
105 * HPROF_TRACE a Java stack trace
106 *
107 * u4 stack trace serial number
108 * u4 thread serial number
109 * u4 number of frames
110 * [id]* stack frame IDs
111 *
112 *
113 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
114 *
115 * u2 flags 0x0001: incremental vs. complete
116 * 0x0002: sorted by allocation vs. live
117 * 0x0004: whether to force a GC
118 * u4 cutoff ratio
119 * u4 total live bytes
120 * u4 total live instances
121 * u8 total bytes allocated
122 * u8 total instances allocated
123 * u4 number of sites that follow
124 * [u1 is_array: 0: normal object
125 * 2: object array
126 * 4: boolean array
127 * 5: char array
128 * 6: float array
129 * 7: double array
130 * 8: byte array
131 * 9: short array
132 * 10: int array
133 * 11: long array
134 * u4 class serial number (may be zero during startup)
135 * u4 stack trace serial number
136 * u4 number of bytes alive
137 * u4 number of instances alive
138 * u4 number of bytes allocated
139 * u4]* number of instance allocated
140 *
141 * HPROF_START_THREAD a newly started thread.
142 *
143 * u4 thread serial number (> 0)
144 * id thread object ID
145 * u4 stack trace serial number
146 * id thread name ID
147 * id thread group name ID
148 * id thread group parent name ID
149 *
150 * HPROF_END_THREAD a terminating thread.
151 *
152 * u4 thread serial number
153 *
154 * HPROF_HEAP_SUMMARY heap summary
155 *
156 * u4 total live bytes
157 * u4 total live instances
158 * u8 total bytes allocated
159 * u8 total instances allocated
160 *
161 * HPROF_HEAP_DUMP denote a heap dump
162 *
163 * [heap dump sub-records]*
164 *
165 * There are four kinds of heap dump sub-records:
166 *
167 * u1 sub-record type
168 *
169 * HPROF_GC_ROOT_UNKNOWN unknown root
170 *
171 * id object ID
172 *
173 * HPROF_GC_ROOT_THREAD_OBJ thread object
174 *
175 * id thread object ID (may be 0 for a
176 * thread newly attached through JNI)
177 * u4 thread sequence number
178 * u4 stack trace sequence number
179 *
180 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
181 *
182 * id object ID
183 * id JNI global ref ID
184 *
185 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
186 *
187 * id object ID
188 * u4 thread serial number
189 * u4 frame # in stack trace (-1 for empty)
190 *
191 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
192 *
193 * id object ID
194 * u4 thread serial number
195 * u4 frame # in stack trace (-1 for empty)
196 *
197 * HPROF_GC_ROOT_NATIVE_STACK Native stack
198 *
199 * id object ID
200 * u4 thread serial number
201 *
202 * HPROF_GC_ROOT_STICKY_CLASS System class
203 *
204 * id object ID
205 *
206 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
207 *
208 * id object ID
209 * u4 thread serial number
210 *
211 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
212 *
213 * id object ID
214 *
215 * HPROF_GC_CLASS_DUMP dump of a class object
216 *
217 * id class object ID
218 * u4 stack trace serial number
219 * id super class object ID
220 * id class loader object ID
221 * id signers object ID
222 * id protection domain object ID
223 * id reserved
224 * id reserved
225 *
226 * u4 instance size (in bytes)
227 *
228 * u2 size of constant pool
229 * [u2, constant pool index,
230 * ty, type
231 * 2: object
232 * 4: boolean
233 * 5: char
234 * 6: float
235 * 7: double
236 * 8: byte
237 * 9: short
238 * 10: int
239 * 11: long
240 * vl]* and value
241 *
242 * u2 number of static fields
243 * [id, static field name,
244 * ty, type,
245 * vl]* and value
246 *
247 * u2 number of inst. fields (not inc. super)
248 * [id, instance field name,
249 * ty]* type
250 *
251 * HPROF_GC_INSTANCE_DUMP dump of a normal object
252 *
253 * id object ID
254 * u4 stack trace serial number
255 * id class object ID
256 * u4 number of bytes that follow
257 * [vl]* instance field values (class, followed
258 * by super, super's super ...)
259 *
260 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
261 *
262 * id array object ID
263 * u4 stack trace serial number
264 * u4 number of elements
265 * id array class ID
266 * [id]* elements
267 *
268 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
269 *
270 * id array object ID
271 * u4 stack trace serial number
272 * u4 number of elements
273 * u1 element type
274 * 4: boolean array
275 * 5: char array
276 * 6: float array
277 * 7: double array
278 * 8: byte array
279 * 9: short array
280 * 10: int array
281 * 11: long array
282 * [u1]* elements
283 *
284 * HPROF_CPU_SAMPLES a set of sample traces of running threads
285 *
286 * u4 total number of samples
287 * u4 # of traces
288 * [u4 # of samples
289 * u4]* stack trace serial number
290 *
291 * HPROF_CONTROL_SETTINGS the settings of on/off switches
292 *
293 * u4 0x00000001: alloc traces on/off
294 * 0x00000002: cpu sampling on/off
295 * u2 stack trace depth
296 *
297 *
298 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
299 * be generated as a sequence of heap dump segments. This sequence is
300 * terminated by an end record. The additional tags allowed by format
301 * "JAVA PROFILE 1.0.2" are:
302 *
303 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
304 *
305 * [heap dump sub-records]*
306 * The same sub-record types allowed by HPROF_HEAP_DUMP
307 *
308 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
309 *
310 */
313 // HPROF tags
315 typedef enum {
316 // top-level records
317 HPROF_UTF8 = 0x01,
318 HPROF_LOAD_CLASS = 0x02,
319 HPROF_UNLOAD_CLASS = 0x03,
320 HPROF_FRAME = 0x04,
321 HPROF_TRACE = 0x05,
322 HPROF_ALLOC_SITES = 0x06,
323 HPROF_HEAP_SUMMARY = 0x07,
324 HPROF_START_THREAD = 0x0A,
325 HPROF_END_THREAD = 0x0B,
326 HPROF_HEAP_DUMP = 0x0C,
327 HPROF_CPU_SAMPLES = 0x0D,
328 HPROF_CONTROL_SETTINGS = 0x0E,
330 // 1.0.2 record types
331 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
332 HPROF_HEAP_DUMP_END = 0x2C,
334 // field types
335 HPROF_ARRAY_OBJECT = 0x01,
336 HPROF_NORMAL_OBJECT = 0x02,
337 HPROF_BOOLEAN = 0x04,
338 HPROF_CHAR = 0x05,
339 HPROF_FLOAT = 0x06,
340 HPROF_DOUBLE = 0x07,
341 HPROF_BYTE = 0x08,
342 HPROF_SHORT = 0x09,
343 HPROF_INT = 0x0A,
344 HPROF_LONG = 0x0B,
346 // data-dump sub-records
347 HPROF_GC_ROOT_UNKNOWN = 0xFF,
348 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
349 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
350 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
351 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
352 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
353 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
354 HPROF_GC_ROOT_MONITOR_USED = 0x07,
355 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
356 HPROF_GC_CLASS_DUMP = 0x20,
357 HPROF_GC_INSTANCE_DUMP = 0x21,
358 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
359 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
360 } hprofTag;
362 // Default stack trace ID (used for dummy HPROF_TRACE record)
363 enum {
364 STACK_TRACE_ID = 1,
365 INITIAL_CLASS_COUNT = 200
366 };
368 // Supports I/O operations on a dump file
370 class DumpWriter : public StackObj {
371 private:
372 enum {
373 io_buffer_size = 8*M
374 };
376 int _fd; // file descriptor (-1 if dump file not open)
377 jlong _bytes_written; // number of byte written to dump file
379 char* _buffer; // internal buffer
380 int _size;
381 int _pos;
383 char* _error; // error message when I/O fails
385 void set_file_descriptor(int fd) { _fd = fd; }
386 int file_descriptor() const { return _fd; }
388 char* buffer() const { return _buffer; }
389 int buffer_size() const { return _size; }
390 int position() const { return _pos; }
391 void set_position(int pos) { _pos = pos; }
393 void set_error(const char* error) { _error = (char*)os::strdup(error); }
395 // all I/O go through this function
396 void write_internal(void* s, int len);
398 public:
399 DumpWriter(const char* path);
400 ~DumpWriter();
402 void close();
403 bool is_open() const { return file_descriptor() >= 0; }
404 void flush();
406 // total number of bytes written to the disk
407 jlong bytes_written() const { return _bytes_written; }
409 // adjust the number of bytes written to disk (used to keep the count
410 // of the number of bytes written in case of rewrites)
411 void adjust_bytes_written(jlong n) { _bytes_written += n; }
413 // number of (buffered) bytes as yet unwritten to the dump file
414 jlong bytes_unwritten() const { return (jlong)position(); }
416 char* error() const { return _error; }
418 jlong current_offset();
419 void seek_to_offset(jlong pos);
421 // writer functions
422 void write_raw(void* s, int len);
423 void write_u1(u1 x) { write_raw((void*)&x, 1); }
424 void write_u2(u2 x);
425 void write_u4(u4 x);
426 void write_u8(u8 x);
427 void write_objectID(oop o);
428 void write_classID(Klass* k);
429 void write_id(u4 x);
430 };
432 DumpWriter::DumpWriter(const char* path) {
433 // try to allocate an I/O buffer of io_buffer_size. If there isn't
434 // sufficient memory then reduce size until we can allocate something.
435 _size = io_buffer_size;
436 do {
437 _buffer = (char*)os::malloc(_size);
438 if (_buffer == NULL) {
439 _size = _size >> 1;
440 }
441 } while (_buffer == NULL && _size > 0);
442 assert((_size > 0 && _buffer != NULL) || (_size == 0 && _buffer == NULL), "sanity check");
443 _pos = 0;
444 _error = NULL;
445 _bytes_written = 0L;
446 _fd = os::create_binary_file(path, false); // don't replace existing file
448 // if the open failed we record the error
449 if (_fd < 0) {
450 _error = (char*)os::strdup(strerror(errno));
451 }
452 }
454 DumpWriter::~DumpWriter() {
455 // flush and close dump file
456 if (is_open()) {
457 close();
458 }
459 if (_buffer != NULL) os::free(_buffer);
460 if (_error != NULL) os::free(_error);
461 }
463 // closes dump file (if open)
464 void DumpWriter::close() {
465 // flush and close dump file
466 if (is_open()) {
467 flush();
468 ::close(file_descriptor());
469 set_file_descriptor(-1);
470 }
471 }
473 // write directly to the file
474 void DumpWriter::write_internal(void* s, int len) {
475 if (is_open()) {
476 int n = ::write(file_descriptor(), s, len);
477 if (n > 0) {
478 _bytes_written += n;
479 }
480 if (n != len) {
481 if (n < 0) {
482 set_error(strerror(errno));
483 } else {
484 set_error("file size limit");
485 }
486 ::close(file_descriptor());
487 set_file_descriptor(-1);
488 }
489 }
490 }
492 // write raw bytes
493 void DumpWriter::write_raw(void* s, int len) {
494 if (is_open()) {
495 // flush buffer to make toom
496 if ((position()+ len) >= buffer_size()) {
497 flush();
498 }
500 // buffer not available or too big to buffer it
501 if ((buffer() == NULL) || (len >= buffer_size())) {
502 write_internal(s, len);
503 } else {
504 // Should optimize this for u1/u2/u4/u8 sizes.
505 memcpy(buffer() + position(), s, len);
506 set_position(position() + len);
507 }
508 }
509 }
511 // flush any buffered bytes to the file
512 void DumpWriter::flush() {
513 if (is_open() && position() > 0) {
514 write_internal(buffer(), position());
515 set_position(0);
516 }
517 }
520 jlong DumpWriter::current_offset() {
521 if (is_open()) {
522 // the offset is the file offset plus whatever we have buffered
523 jlong offset = os::current_file_offset(file_descriptor());
524 assert(offset >= 0, "lseek failed");
525 return offset + (jlong)position();
526 } else {
527 return (jlong)-1;
528 }
529 }
531 void DumpWriter::seek_to_offset(jlong off) {
532 assert(off >= 0, "bad offset");
534 // need to flush before seeking
535 flush();
537 // may be closed due to I/O error
538 if (is_open()) {
539 jlong n = os::seek_to_file_offset(file_descriptor(), off);
540 assert(n >= 0, "lseek failed");
541 }
542 }
544 void DumpWriter::write_u2(u2 x) {
545 u2 v;
546 Bytes::put_Java_u2((address)&v, x);
547 write_raw((void*)&v, 2);
548 }
550 void DumpWriter::write_u4(u4 x) {
551 u4 v;
552 Bytes::put_Java_u4((address)&v, x);
553 write_raw((void*)&v, 4);
554 }
556 void DumpWriter::write_u8(u8 x) {
557 u8 v;
558 Bytes::put_Java_u8((address)&v, x);
559 write_raw((void*)&v, 8);
560 }
562 void DumpWriter::write_objectID(oop o) {
563 address a = (address)((uintptr_t)o);
564 #ifdef _LP64
565 write_u8((u8)a);
566 #else
567 write_u4((u4)a);
568 #endif
569 }
571 void DumpWriter::write_id(u4 x) {
572 #ifdef _LP64
573 write_u8((u8) x);
574 #else
575 write_u4(x);
576 #endif
577 }
579 // We use java mirror as the class ID
580 void DumpWriter::write_classID(Klass* k) {
581 write_objectID(k->java_mirror());
582 }
586 // Support class with a collection of functions used when dumping the heap
588 class DumperSupport : AllStatic {
589 public:
591 // write a header of the given type
592 static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
594 // returns hprof tag for the given type signature
595 static hprofTag sig2tag(symbolOop sig);
596 // returns hprof tag for the given basic type
597 static hprofTag type2tag(BasicType type);
599 // returns the size of the instance of the given class
600 static u4 instance_size(klassOop k);
602 // dump a jfloat
603 static void dump_float(DumpWriter* writer, jfloat f);
604 // dump a jdouble
605 static void dump_double(DumpWriter* writer, jdouble d);
606 // dumps the raw value of the given field
607 static void dump_field_value(DumpWriter* writer, char type, address addr);
608 // dumps static fields of the given class
609 static void dump_static_fields(DumpWriter* writer, klassOop k);
610 // dump the raw values of the instance fields of the given object
611 static void dump_instance_fields(DumpWriter* writer, oop o);
612 // dumps the definition of the instance fields for a given class
613 static void dump_instance_field_descriptors(DumpWriter* writer, klassOop k);
614 // creates HPROF_GC_INSTANCE_DUMP record for the given object
615 static void dump_instance(DumpWriter* writer, oop o);
616 // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
617 // array classes
618 static void dump_class_and_array_classes(DumpWriter* writer, klassOop k);
619 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
620 // class (and each multi-dimensional array class too)
621 static void dump_basic_type_array_class(DumpWriter* writer, klassOop k);
623 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
624 static void dump_object_array(DumpWriter* writer, objArrayOop array);
625 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
626 static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
627 // create HPROF_FRAME record for the given method and bci
628 static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, methodOop m, int bci);
629 };
631 // write a header of the given type
632 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
633 writer->write_u1((u1)tag);
634 writer->write_u4(0); // current ticks
635 writer->write_u4(len);
636 }
638 // returns hprof tag for the given type signature
639 hprofTag DumperSupport::sig2tag(symbolOop sig) {
640 switch (sig->byte_at(0)) {
641 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
642 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
643 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
644 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
645 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
646 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
647 case JVM_SIGNATURE_INT : return HPROF_INT;
648 case JVM_SIGNATURE_LONG : return HPROF_LONG;
649 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
650 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
651 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
652 }
653 }
655 hprofTag DumperSupport::type2tag(BasicType type) {
656 switch (type) {
657 case T_BYTE : return HPROF_BYTE;
658 case T_CHAR : return HPROF_CHAR;
659 case T_FLOAT : return HPROF_FLOAT;
660 case T_DOUBLE : return HPROF_DOUBLE;
661 case T_INT : return HPROF_INT;
662 case T_LONG : return HPROF_LONG;
663 case T_SHORT : return HPROF_SHORT;
664 case T_BOOLEAN : return HPROF_BOOLEAN;
665 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
666 }
667 }
669 // dump a jfloat
670 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
671 if (g_isnan(f)) {
672 writer->write_u4(0x7fc00000); // collapsing NaNs
673 } else {
674 union {
675 int i;
676 float f;
677 } u;
678 u.f = (float)f;
679 writer->write_u4((u4)u.i);
680 }
681 }
683 // dump a jdouble
684 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
685 union {
686 jlong l;
687 double d;
688 } u;
689 if (g_isnan(d)) { // collapsing NaNs
690 u.l = (jlong)(0x7ff80000);
691 u.l = (u.l << 32);
692 } else {
693 u.d = (double)d;
694 }
695 writer->write_u8((u8)u.l);
696 }
698 // dumps the raw value of the given field
699 void DumperSupport::dump_field_value(DumpWriter* writer, char type, address addr) {
700 switch (type) {
701 case JVM_SIGNATURE_CLASS :
702 case JVM_SIGNATURE_ARRAY : {
703 oop o;
704 if (UseCompressedOops) {
705 o = oopDesc::load_decode_heap_oop((narrowOop*)addr);
706 } else {
707 o = oopDesc::load_decode_heap_oop((oop*)addr);
708 }
710 // reflection and sun.misc.Unsafe classes may have a reference to a
711 // klassOop so filter it out.
712 if (o != NULL && o->is_klass()) {
713 o = NULL;
714 }
716 // FIXME: When sharing is enabled we don't emit field references to objects
717 // in shared spaces. We can remove this once we write records for the classes
718 // and strings that are shared.
719 if (o != NULL && o->is_shared()) {
720 o = NULL;
721 }
722 writer->write_objectID(o);
723 break;
724 }
725 case JVM_SIGNATURE_BYTE : {
726 jbyte* b = (jbyte*)addr;
727 writer->write_u1((u1)*b);
728 break;
729 }
730 case JVM_SIGNATURE_CHAR : {
731 jchar* c = (jchar*)addr;
732 writer->write_u2((u2)*c);
733 break;
734 }
735 case JVM_SIGNATURE_SHORT : {
736 jshort* s = (jshort*)addr;
737 writer->write_u2((u2)*s);
738 break;
739 }
740 case JVM_SIGNATURE_FLOAT : {
741 jfloat* f = (jfloat*)addr;
742 dump_float(writer, *f);
743 break;
744 }
745 case JVM_SIGNATURE_DOUBLE : {
746 jdouble* f = (jdouble*)addr;
747 dump_double(writer, *f);
748 break;
749 }
750 case JVM_SIGNATURE_INT : {
751 jint* i = (jint*)addr;
752 writer->write_u4((u4)*i);
753 break;
754 }
755 case JVM_SIGNATURE_LONG : {
756 jlong* l = (jlong*)addr;
757 writer->write_u8((u8)*l);
758 break;
759 }
760 case JVM_SIGNATURE_BOOLEAN : {
761 jboolean* b = (jboolean*)addr;
762 writer->write_u1((u1)*b);
763 break;
764 }
765 default : ShouldNotReachHere();
766 }
767 }
769 // returns the size of the instance of the given class
770 u4 DumperSupport::instance_size(klassOop k) {
771 HandleMark hm;
772 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
774 int size = 0;
776 for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
777 if (!fld.access_flags().is_static()) {
778 symbolOop sig = fld.signature();
779 switch (sig->byte_at(0)) {
780 case JVM_SIGNATURE_CLASS :
781 case JVM_SIGNATURE_ARRAY : size += oopSize; break;
783 case JVM_SIGNATURE_BYTE :
784 case JVM_SIGNATURE_BOOLEAN : size += 1; break;
786 case JVM_SIGNATURE_CHAR :
787 case JVM_SIGNATURE_SHORT : size += 2; break;
789 case JVM_SIGNATURE_INT :
790 case JVM_SIGNATURE_FLOAT : size += 4; break;
792 case JVM_SIGNATURE_LONG :
793 case JVM_SIGNATURE_DOUBLE : size += 8; break;
795 default : ShouldNotReachHere();
796 }
797 }
798 }
799 return (u4)size;
800 }
802 // dumps static fields of the given class
803 void DumperSupport::dump_static_fields(DumpWriter* writer, klassOop k) {
804 HandleMark hm;
805 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
807 // pass 1 - count the static fields
808 u2 field_count = 0;
809 for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
810 if (fldc.access_flags().is_static()) field_count++;
811 }
813 writer->write_u2(field_count);
815 // pass 2 - dump the field descriptors and raw values
816 for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
817 if (fld.access_flags().is_static()) {
818 symbolOop sig = fld.signature();
820 writer->write_objectID(fld.name()); // name
821 writer->write_u1(sig2tag(sig)); // type
823 // value
824 int offset = fld.offset();
825 address addr = (address)k + offset;
827 dump_field_value(writer, sig->byte_at(0), addr);
828 }
829 }
830 }
832 // dump the raw values of the instance fields of the given object
833 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
834 HandleMark hm;
835 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), o->klass());
837 for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
838 if (!fld.access_flags().is_static()) {
839 symbolOop sig = fld.signature();
840 address addr = (address)o + fld.offset();
842 dump_field_value(writer, sig->byte_at(0), addr);
843 }
844 }
845 }
847 // dumps the definition of the instance fields for a given class
848 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, klassOop k) {
849 HandleMark hm;
850 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
852 // pass 1 - count the instance fields
853 u2 field_count = 0;
854 for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
855 if (!fldc.access_flags().is_static()) field_count++;
856 }
858 writer->write_u2(field_count);
860 // pass 2 - dump the field descriptors
861 for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
862 if (!fld.access_flags().is_static()) {
863 symbolOop sig = fld.signature();
865 writer->write_objectID(fld.name()); // name
866 writer->write_u1(sig2tag(sig)); // type
867 }
868 }
869 }
871 // creates HPROF_GC_INSTANCE_DUMP record for the given object
872 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
873 klassOop k = o->klass();
875 writer->write_u1(HPROF_GC_INSTANCE_DUMP);
876 writer->write_objectID(o);
877 writer->write_u4(STACK_TRACE_ID);
879 // class ID
880 writer->write_classID(Klass::cast(k));
882 // number of bytes that follow
883 writer->write_u4(instance_size(k) );
885 // field values
886 dump_instance_fields(writer, o);
887 }
889 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
890 // its array classes
891 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, klassOop k) {
892 Klass* klass = Klass::cast(k);
893 assert(klass->oop_is_instance(), "not an instanceKlass");
894 instanceKlass* ik = (instanceKlass*)klass;
896 writer->write_u1(HPROF_GC_CLASS_DUMP);
898 // class ID
899 writer->write_classID(ik);
900 writer->write_u4(STACK_TRACE_ID);
902 // super class ID
903 klassOop java_super = ik->java_super();
904 if (java_super == NULL) {
905 writer->write_objectID(NULL);
906 } else {
907 writer->write_classID(Klass::cast(java_super));
908 }
910 writer->write_objectID(ik->class_loader());
911 writer->write_objectID(ik->signers());
912 writer->write_objectID(ik->protection_domain());
914 // reserved
915 writer->write_objectID(NULL);
916 writer->write_objectID(NULL);
918 // instance size
919 writer->write_u4(DumperSupport::instance_size(k));
921 // size of constant pool - ignored by HAT 1.1
922 writer->write_u2(0);
924 // number of static fields
925 dump_static_fields(writer, k);
927 // description of instance fields
928 dump_instance_field_descriptors(writer, k);
930 // array classes
931 k = klass->array_klass_or_null();
932 while (k != NULL) {
933 Klass* klass = Klass::cast(k);
934 assert(klass->oop_is_objArray(), "not an objArrayKlass");
936 writer->write_u1(HPROF_GC_CLASS_DUMP);
937 writer->write_classID(klass);
938 writer->write_u4(STACK_TRACE_ID);
940 // super class of array classes is java.lang.Object
941 java_super = klass->java_super();
942 assert(java_super != NULL, "checking");
943 writer->write_classID(Klass::cast(java_super));
945 writer->write_objectID(ik->class_loader());
946 writer->write_objectID(ik->signers());
947 writer->write_objectID(ik->protection_domain());
949 writer->write_objectID(NULL); // reserved
950 writer->write_objectID(NULL);
951 writer->write_u4(0); // instance size
952 writer->write_u2(0); // constant pool
953 writer->write_u2(0); // static fields
954 writer->write_u2(0); // instance fields
956 // get the array class for the next rank
957 k = klass->array_klass_or_null();
958 }
959 }
961 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
962 // class (and each multi-dimensional array class too)
963 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, klassOop k) {
964 // array classes
965 while (k != NULL) {
966 Klass* klass = Klass::cast(k);
968 writer->write_u1(HPROF_GC_CLASS_DUMP);
969 writer->write_classID(klass);
970 writer->write_u4(STACK_TRACE_ID);
972 // super class of array classes is java.lang.Object
973 klassOop java_super = klass->java_super();
974 assert(java_super != NULL, "checking");
975 writer->write_classID(Klass::cast(java_super));
977 writer->write_objectID(NULL); // loader
978 writer->write_objectID(NULL); // signers
979 writer->write_objectID(NULL); // protection domain
981 writer->write_objectID(NULL); // reserved
982 writer->write_objectID(NULL);
983 writer->write_u4(0); // instance size
984 writer->write_u2(0); // constant pool
985 writer->write_u2(0); // static fields
986 writer->write_u2(0); // instance fields
988 // get the array class for the next rank
989 k = klass->array_klass_or_null();
990 }
991 }
993 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
994 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
996 // filter this
997 if (array->klass() == Universe::systemObjArrayKlassObj()) return;
999 writer->write_u1(HPROF_GC_OBJ_ARRAY_DUMP);
1000 writer->write_objectID(array);
1001 writer->write_u4(STACK_TRACE_ID);
1002 writer->write_u4((u4)array->length());
1004 // array class ID
1005 writer->write_classID(Klass::cast(array->klass()));
1007 // [id]* elements
1008 for (int index=0; index<array->length(); index++) {
1009 oop o = array->obj_at(index);
1010 writer->write_objectID(o);
1011 }
1012 }
1014 #define WRITE_ARRAY(Array, Type, Size) \
1015 for (int i=0; i<Array->length(); i++) { writer->write_##Size((Size)array->Type##_at(i)); }
1018 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1019 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
1020 BasicType type = typeArrayKlass::cast(array->klass())->element_type();
1022 writer->write_u1(HPROF_GC_PRIM_ARRAY_DUMP);
1023 writer->write_objectID(array);
1024 writer->write_u4(STACK_TRACE_ID);
1025 writer->write_u4((u4)array->length());
1026 writer->write_u1(type2tag(type));
1028 // nothing to copy
1029 if (array->length() == 0) {
1030 return;
1031 }
1033 // If the byte ordering is big endian then we can copy most types directly
1034 int length_in_bytes = array->length() * type2aelembytes(type);
1035 assert(length_in_bytes > 0, "nothing to copy");
1037 switch (type) {
1038 case T_INT : {
1039 if (Bytes::is_Java_byte_ordering_different()) {
1040 WRITE_ARRAY(array, int, u4);
1041 } else {
1042 writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
1043 }
1044 break;
1045 }
1046 case T_BYTE : {
1047 writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
1048 break;
1049 }
1050 case T_CHAR : {
1051 if (Bytes::is_Java_byte_ordering_different()) {
1052 WRITE_ARRAY(array, char, u2);
1053 } else {
1054 writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
1055 }
1056 break;
1057 }
1058 case T_SHORT : {
1059 if (Bytes::is_Java_byte_ordering_different()) {
1060 WRITE_ARRAY(array, short, u2);
1061 } else {
1062 writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
1063 }
1064 break;
1065 }
1066 case T_BOOLEAN : {
1067 if (Bytes::is_Java_byte_ordering_different()) {
1068 WRITE_ARRAY(array, bool, u1);
1069 } else {
1070 writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
1071 }
1072 break;
1073 }
1074 case T_LONG : {
1075 if (Bytes::is_Java_byte_ordering_different()) {
1076 WRITE_ARRAY(array, long, u8);
1077 } else {
1078 writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
1079 }
1080 break;
1081 }
1083 // handle float/doubles in a special value to ensure than NaNs are
1084 // written correctly. TO DO: Check if we can avoid this on processors that
1085 // use IEEE 754.
1087 case T_FLOAT : {
1088 for (int i=0; i<array->length(); i++) {
1089 dump_float( writer, array->float_at(i) );
1090 }
1091 break;
1092 }
1093 case T_DOUBLE : {
1094 for (int i=0; i<array->length(); i++) {
1095 dump_double( writer, array->double_at(i) );
1096 }
1097 break;
1098 }
1099 default : ShouldNotReachHere();
1100 }
1101 }
1103 // create a HPROF_FRAME record of the given methodOop and bci
1104 void DumperSupport::dump_stack_frame(DumpWriter* writer,
1105 int frame_serial_num,
1106 int class_serial_num,
1107 methodOop m,
1108 int bci) {
1109 int line_number;
1110 if (m->is_native()) {
1111 line_number = -3; // native frame
1112 } else {
1113 line_number = m->line_number_from_bci(bci);
1114 }
1116 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1117 writer->write_id(frame_serial_num); // frame serial number
1118 writer->write_objectID(m->name()); // method's name
1119 writer->write_objectID(m->signature()); // method's signature
1121 assert(Klass::cast(m->method_holder())->oop_is_instance(), "not instanceKlass");
1122 writer->write_objectID(instanceKlass::cast(m->method_holder())->source_file_name()); // source file name
1123 writer->write_u4(class_serial_num); // class serial number
1124 writer->write_u4((u4) line_number); // line number
1125 }
1127 // Support class used to generate HPROF_UTF8 records from the entries in the
1128 // SymbolTable.
1130 class SymbolTableDumper : public OopClosure {
1131 private:
1132 DumpWriter* _writer;
1133 DumpWriter* writer() const { return _writer; }
1134 public:
1135 SymbolTableDumper(DumpWriter* writer) { _writer = writer; }
1136 void do_oop(oop* obj_p);
1137 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1138 };
1140 void SymbolTableDumper::do_oop(oop* obj_p) {
1141 ResourceMark rm;
1142 symbolOop sym = (symbolOop)*obj_p;
1144 int len = sym->utf8_length();
1145 if (len > 0) {
1146 char* s = sym->as_utf8();
1147 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1148 writer()->write_objectID(sym);
1149 writer()->write_raw(s, len);
1150 }
1151 }
1154 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1156 class JNILocalsDumper : public OopClosure {
1157 private:
1158 DumpWriter* _writer;
1159 u4 _thread_serial_num;
1160 int _frame_num;
1161 DumpWriter* writer() const { return _writer; }
1162 public:
1163 JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
1164 _writer = writer;
1165 _thread_serial_num = thread_serial_num;
1166 _frame_num = -1; // default - empty stack
1167 }
1168 void set_frame_number(int n) { _frame_num = n; }
1169 void do_oop(oop* obj_p);
1170 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1171 };
1174 void JNILocalsDumper::do_oop(oop* obj_p) {
1175 // ignore null or deleted handles
1176 oop o = *obj_p;
1177 if (o != NULL && o != JNIHandles::deleted_handle()) {
1178 writer()->write_u1(HPROF_GC_ROOT_JNI_LOCAL);
1179 writer()->write_objectID(o);
1180 writer()->write_u4(_thread_serial_num);
1181 writer()->write_u4((u4)_frame_num);
1182 }
1183 }
1186 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
1188 class JNIGlobalsDumper : public OopClosure {
1189 private:
1190 DumpWriter* _writer;
1191 DumpWriter* writer() const { return _writer; }
1193 public:
1194 JNIGlobalsDumper(DumpWriter* writer) {
1195 _writer = writer;
1196 }
1197 void do_oop(oop* obj_p);
1198 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1199 };
1201 void JNIGlobalsDumper::do_oop(oop* obj_p) {
1202 oop o = *obj_p;
1204 // ignore these
1205 if (o == NULL || o == JNIHandles::deleted_handle()) return;
1207 // we ignore global ref to symbols and other internal objects
1208 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
1209 writer()->write_u1(HPROF_GC_ROOT_JNI_GLOBAL);
1210 writer()->write_objectID(o);
1211 writer()->write_objectID((oopDesc*)obj_p); // global ref ID
1212 }
1213 };
1216 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
1218 class MonitorUsedDumper : public OopClosure {
1219 private:
1220 DumpWriter* _writer;
1221 DumpWriter* writer() const { return _writer; }
1222 public:
1223 MonitorUsedDumper(DumpWriter* writer) {
1224 _writer = writer;
1225 }
1226 void do_oop(oop* obj_p) {
1227 writer()->write_u1(HPROF_GC_ROOT_MONITOR_USED);
1228 writer()->write_objectID(*obj_p);
1229 }
1230 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1231 };
1234 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
1236 class StickyClassDumper : public OopClosure {
1237 private:
1238 DumpWriter* _writer;
1239 DumpWriter* writer() const { return _writer; }
1240 public:
1241 StickyClassDumper(DumpWriter* writer) {
1242 _writer = writer;
1243 }
1244 void do_oop(oop* obj_p);
1245 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1246 };
1248 void StickyClassDumper::do_oop(oop* obj_p) {
1249 if (*obj_p != NULL) {
1250 oop o = *obj_p;
1251 if (o->is_klass()) {
1252 klassOop k = klassOop(o);
1253 if (Klass::cast(k)->oop_is_instance()) {
1254 instanceKlass* ik = instanceKlass::cast(k);
1255 writer()->write_u1(HPROF_GC_ROOT_STICKY_CLASS);
1256 writer()->write_classID(ik);
1257 }
1258 }
1259 }
1260 }
1263 class VM_HeapDumper;
1265 // Support class using when iterating over the heap.
1267 class HeapObjectDumper : public ObjectClosure {
1268 private:
1269 VM_HeapDumper* _dumper;
1270 DumpWriter* _writer;
1272 VM_HeapDumper* dumper() { return _dumper; }
1273 DumpWriter* writer() { return _writer; }
1275 // used to indicate that a record has been writen
1276 void mark_end_of_record();
1278 public:
1279 HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
1280 _dumper = dumper;
1281 _writer = writer;
1282 }
1284 // called for each object in the heap
1285 void do_object(oop o);
1286 };
1288 void HeapObjectDumper::do_object(oop o) {
1289 // hide the sentinel for deleted handles
1290 if (o == JNIHandles::deleted_handle()) return;
1292 // ignore KlassKlass objects
1293 if (o->is_klass()) return;
1295 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
1296 if (o->klass() == SystemDictionary::Class_klass()) {
1297 if (!java_lang_Class::is_primitive(o)) {
1298 return;
1299 }
1300 }
1302 // create a HPROF_GC_INSTANCE record for each object
1303 if (o->is_instance()) {
1304 DumperSupport::dump_instance(writer(), o);
1305 mark_end_of_record();
1306 } else {
1307 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
1308 if (o->is_objArray()) {
1309 DumperSupport::dump_object_array(writer(), objArrayOop(o));
1310 mark_end_of_record();
1311 } else {
1312 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
1313 if (o->is_typeArray()) {
1314 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
1315 mark_end_of_record();
1316 }
1317 }
1318 }
1319 }
1321 // The VM operation that performs the heap dump
1322 class VM_HeapDumper : public VM_GC_Operation {
1323 private:
1324 static VM_HeapDumper* _global_dumper;
1325 static DumpWriter* _global_writer;
1326 DumpWriter* _local_writer;
1327 JavaThread* _oome_thread;
1328 methodOop _oome_constructor;
1329 bool _gc_before_heap_dump;
1330 bool _is_segmented_dump;
1331 jlong _dump_start;
1332 GrowableArray<Klass*>* _klass_map;
1333 ThreadStackTrace** _stack_traces;
1334 int _num_threads;
1336 // accessors and setters
1337 static VM_HeapDumper* dumper() { assert(_global_dumper != NULL, "Error"); return _global_dumper; }
1338 static DumpWriter* writer() { assert(_global_writer != NULL, "Error"); return _global_writer; }
1339 void set_global_dumper() {
1340 assert(_global_dumper == NULL, "Error");
1341 _global_dumper = this;
1342 }
1343 void set_global_writer() {
1344 assert(_global_writer == NULL, "Error");
1345 _global_writer = _local_writer;
1346 }
1347 void clear_global_dumper() { _global_dumper = NULL; }
1348 void clear_global_writer() { _global_writer = NULL; }
1350 bool is_segmented_dump() const { return _is_segmented_dump; }
1351 void set_segmented_dump() { _is_segmented_dump = true; }
1352 jlong dump_start() const { return _dump_start; }
1353 void set_dump_start(jlong pos);
1355 bool skip_operation() const;
1357 // writes a HPROF_LOAD_CLASS record
1358 static void do_load_class(klassOop k);
1360 // writes a HPROF_GC_CLASS_DUMP record for the given class
1361 // (and each array class too)
1362 static void do_class_dump(klassOop k);
1364 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1365 // array (and each multi-dimensional array too)
1366 static void do_basic_type_array_class_dump(klassOop k);
1368 // HPROF_GC_ROOT_THREAD_OBJ records
1369 int do_thread(JavaThread* thread, u4 thread_serial_num);
1370 void do_threads();
1372 void add_class_serial_number(Klass* k, int serial_num) {
1373 _klass_map->at_put_grow(serial_num, k);
1374 }
1376 // HPROF_TRACE and HPROF_FRAME records
1377 void dump_stack_traces();
1379 // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
1380 void write_dump_header();
1382 // fixes up the length of the current dump record
1383 void write_current_dump_record_length();
1385 // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
1386 // record in the case of a segmented heap dump)
1387 void end_of_dump();
1389 public:
1390 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
1391 VM_GC_Operation(0 /* total collections, dummy, ignored */,
1392 0 /* total full collections, dummy, ignored */,
1393 gc_before_heap_dump) {
1394 _local_writer = writer;
1395 _gc_before_heap_dump = gc_before_heap_dump;
1396 _is_segmented_dump = false;
1397 _dump_start = (jlong)-1;
1398 _klass_map = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
1399 _stack_traces = NULL;
1400 _num_threads = 0;
1401 if (oome) {
1402 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
1403 // get OutOfMemoryError zero-parameter constructor
1404 instanceKlass* oome_ik = instanceKlass::cast(SystemDictionary::OutOfMemoryError_klass());
1405 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
1406 vmSymbols::void_method_signature());
1407 // get thread throwing OOME when generating the heap dump at OOME
1408 _oome_thread = JavaThread::current();
1409 } else {
1410 _oome_thread = NULL;
1411 _oome_constructor = NULL;
1412 }
1413 }
1414 ~VM_HeapDumper() {
1415 if (_stack_traces != NULL) {
1416 for (int i=0; i < _num_threads; i++) {
1417 delete _stack_traces[i];
1418 }
1419 FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces);
1420 }
1421 delete _klass_map;
1422 }
1424 VMOp_Type type() const { return VMOp_HeapDumper; }
1425 // used to mark sub-record boundary
1426 void check_segment_length();
1427 void doit();
1428 };
1430 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
1431 DumpWriter* VM_HeapDumper::_global_writer = NULL;
1433 bool VM_HeapDumper::skip_operation() const {
1434 return false;
1435 }
1437 // sets the dump starting position
1438 void VM_HeapDumper::set_dump_start(jlong pos) {
1439 _dump_start = pos;
1440 }
1442 // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
1443 void VM_HeapDumper::write_dump_header() {
1444 if (writer()->is_open()) {
1445 if (is_segmented_dump()) {
1446 writer()->write_u1(HPROF_HEAP_DUMP_SEGMENT);
1447 } else {
1448 writer()->write_u1(HPROF_HEAP_DUMP);
1449 }
1450 writer()->write_u4(0); // current ticks
1452 // record the starting position for the dump (its length will be fixed up later)
1453 set_dump_start(writer()->current_offset());
1454 writer()->write_u4(0);
1455 }
1456 }
1458 // fixes up the length of the current dump record
1459 void VM_HeapDumper::write_current_dump_record_length() {
1460 if (writer()->is_open()) {
1461 assert(dump_start() >= 0, "no dump start recorded");
1463 // calculate the size of the dump record
1464 jlong dump_end = writer()->current_offset();
1465 jlong dump_len = (dump_end - dump_start() - 4);
1467 // record length must fit in a u4
1468 if (dump_len > (jlong)(4L*(jlong)G)) {
1469 warning("record is too large");
1470 }
1472 // seek to the dump start and fix-up the length
1473 writer()->seek_to_offset(dump_start());
1474 writer()->write_u4((u4)dump_len);
1476 // adjust the total size written to keep the bytes written correct.
1477 writer()->adjust_bytes_written(-((long) sizeof(u4)));
1479 // seek to dump end so we can continue
1480 writer()->seek_to_offset(dump_end);
1482 // no current dump record
1483 set_dump_start((jlong)-1);
1484 }
1485 }
1487 // used on a sub-record boundary to check if we need to start a
1488 // new segment.
1489 void VM_HeapDumper::check_segment_length() {
1490 if (writer()->is_open()) {
1491 if (is_segmented_dump()) {
1492 // don't use current_offset that would be too expensive on a per record basis
1493 jlong dump_end = writer()->bytes_written() + writer()->bytes_unwritten();
1494 assert(dump_end == writer()->current_offset(), "checking");
1495 jlong dump_len = (dump_end - dump_start() - 4);
1496 assert(dump_len >= 0 && dump_len <= max_juint, "bad dump length");
1498 if (dump_len > (jlong)HeapDumpSegmentSize) {
1499 write_current_dump_record_length();
1500 write_dump_header();
1501 }
1502 }
1503 }
1504 }
1506 // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
1507 // record in the case of a segmented heap dump)
1508 void VM_HeapDumper::end_of_dump() {
1509 if (writer()->is_open()) {
1510 write_current_dump_record_length();
1512 // for segmented dump we write the end record
1513 if (is_segmented_dump()) {
1514 writer()->write_u1(HPROF_HEAP_DUMP_END);
1515 writer()->write_u4(0);
1516 writer()->write_u4(0);
1517 }
1518 }
1519 }
1521 // marks sub-record boundary
1522 void HeapObjectDumper::mark_end_of_record() {
1523 dumper()->check_segment_length();
1524 }
1526 // writes a HPROF_LOAD_CLASS record for the class (and each of its
1527 // array classes)
1528 void VM_HeapDumper::do_load_class(klassOop k) {
1529 static u4 class_serial_num = 0;
1531 // len of HPROF_LOAD_CLASS record
1532 u4 remaining = 2*oopSize + 2*sizeof(u4);
1534 // write a HPROF_LOAD_CLASS for the class and each array class
1535 do {
1536 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
1538 // class serial number is just a number
1539 writer()->write_u4(++class_serial_num);
1541 // class ID
1542 Klass* klass = Klass::cast(k);
1543 writer()->write_classID(klass);
1545 // add the klassOop and class serial number pair
1546 dumper()->add_class_serial_number(klass, class_serial_num);
1548 writer()->write_u4(STACK_TRACE_ID);
1550 // class name ID
1551 symbolOop name = klass->name();
1552 writer()->write_objectID(name);
1554 // write a LOAD_CLASS record for the array type (if it exists)
1555 k = klass->array_klass_or_null();
1556 } while (k != NULL);
1557 }
1559 // writes a HPROF_GC_CLASS_DUMP record for the given class
1560 void VM_HeapDumper::do_class_dump(klassOop k) {
1561 DumperSupport::dump_class_and_array_classes(writer(), k);
1562 }
1564 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1565 // array (and each multi-dimensional array too)
1566 void VM_HeapDumper::do_basic_type_array_class_dump(klassOop k) {
1567 DumperSupport::dump_basic_type_array_class(writer(), k);
1568 }
1570 // Walk the stack of the given thread.
1571 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
1572 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
1573 //
1574 // It returns the number of Java frames in this thread stack
1575 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
1576 JNILocalsDumper blk(writer(), thread_serial_num);
1578 oop threadObj = java_thread->threadObj();
1579 assert(threadObj != NULL, "sanity check");
1581 int stack_depth = 0;
1582 if (java_thread->has_last_Java_frame()) {
1584 // vframes are resource allocated
1585 Thread* current_thread = Thread::current();
1586 ResourceMark rm(current_thread);
1587 HandleMark hm(current_thread);
1589 RegisterMap reg_map(java_thread);
1590 frame f = java_thread->last_frame();
1591 vframe* vf = vframe::new_vframe(&f, ®_map, java_thread);
1592 frame* last_entry_frame = NULL;
1593 int extra_frames = 0;
1595 if (java_thread == _oome_thread && _oome_constructor != NULL) {
1596 extra_frames++;
1597 }
1598 while (vf != NULL) {
1599 blk.set_frame_number(stack_depth);
1600 if (vf->is_java_frame()) {
1602 // java frame (interpreted, compiled, ...)
1603 javaVFrame *jvf = javaVFrame::cast(vf);
1604 if (!(jvf->method()->is_native())) {
1605 StackValueCollection* locals = jvf->locals();
1606 for (int slot=0; slot<locals->size(); slot++) {
1607 if (locals->at(slot)->type() == T_OBJECT) {
1608 oop o = locals->obj_at(slot)();
1610 if (o != NULL) {
1611 writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME);
1612 writer()->write_objectID(o);
1613 writer()->write_u4(thread_serial_num);
1614 writer()->write_u4((u4) (stack_depth + extra_frames));
1615 }
1616 }
1617 }
1618 } else {
1619 // native frame
1620 if (stack_depth == 0) {
1621 // JNI locals for the top frame.
1622 java_thread->active_handles()->oops_do(&blk);
1623 } else {
1624 if (last_entry_frame != NULL) {
1625 // JNI locals for the entry frame
1626 assert(last_entry_frame->is_entry_frame(), "checking");
1627 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
1628 }
1629 }
1630 }
1631 // increment only for Java frames
1632 stack_depth++;
1633 last_entry_frame = NULL;
1635 } else {
1636 // externalVFrame - if it's an entry frame then report any JNI locals
1637 // as roots when we find the corresponding native javaVFrame
1638 frame* fr = vf->frame_pointer();
1639 assert(fr != NULL, "sanity check");
1640 if (fr->is_entry_frame()) {
1641 last_entry_frame = fr;
1642 }
1643 }
1644 vf = vf->sender();
1645 }
1646 } else {
1647 // no last java frame but there may be JNI locals
1648 java_thread->active_handles()->oops_do(&blk);
1649 }
1650 return stack_depth;
1651 }
1654 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
1655 // the stack so that locals and JNI locals are dumped.
1656 void VM_HeapDumper::do_threads() {
1657 for (int i=0; i < _num_threads; i++) {
1658 JavaThread* thread = _stack_traces[i]->thread();
1659 oop threadObj = thread->threadObj();
1660 u4 thread_serial_num = i+1;
1661 u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
1662 writer()->write_u1(HPROF_GC_ROOT_THREAD_OBJ);
1663 writer()->write_objectID(threadObj);
1664 writer()->write_u4(thread_serial_num); // thread number
1665 writer()->write_u4(stack_serial_num); // stack trace serial number
1666 int num_frames = do_thread(thread, thread_serial_num);
1667 assert(num_frames == _stack_traces[i]->get_stack_depth(),
1668 "total number of Java frames not matched");
1669 }
1670 }
1673 // The VM operation that dumps the heap. The dump consists of the following
1674 // records:
1675 //
1676 // HPROF_HEADER
1677 // [HPROF_UTF8]*
1678 // [HPROF_LOAD_CLASS]*
1679 // [[HPROF_FRAME]*|HPROF_TRACE]*
1680 // [HPROF_GC_CLASS_DUMP]*
1681 // HPROF_HEAP_DUMP
1682 //
1683 // The HPROF_TRACE records represent the stack traces where the heap dump
1684 // is generated and a "dummy trace" record which does not include
1685 // any frames. The dummy trace record is used to be referenced as the
1686 // unknown object alloc site.
1687 //
1688 // The HPROF_HEAP_DUMP record has a length following by sub-records. To allow
1689 // the heap dump be generated in a single pass we remember the position of
1690 // the dump length and fix it up after all sub-records have been written.
1691 // To generate the sub-records we iterate over the heap, writing
1692 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
1693 // records as we go. Once that is done we write records for some of the GC
1694 // roots.
1696 void VM_HeapDumper::doit() {
1698 HandleMark hm;
1699 CollectedHeap* ch = Universe::heap();
1700 if (_gc_before_heap_dump) {
1701 ch->collect_as_vm_thread(GCCause::_heap_dump);
1702 } else {
1703 // make the heap parsable (no need to retire TLABs)
1704 ch->ensure_parsability(false);
1705 }
1707 // At this point we should be the only dumper active, so
1708 // the following should be safe.
1709 set_global_dumper();
1710 set_global_writer();
1712 // Write the file header - use 1.0.2 for large heaps, otherwise 1.0.1
1713 size_t used = ch->used();
1714 const char* header;
1715 if (used > (size_t)SegmentedHeapDumpThreshold) {
1716 set_segmented_dump();
1717 header = "JAVA PROFILE 1.0.2";
1718 } else {
1719 header = "JAVA PROFILE 1.0.1";
1720 }
1722 // header is few bytes long - no chance to overflow int
1723 writer()->write_raw((void*)header, (int)strlen(header));
1724 writer()->write_u1(0); // terminator
1725 writer()->write_u4(oopSize);
1726 writer()->write_u8(os::javaTimeMillis());
1728 // HPROF_UTF8 records
1729 SymbolTableDumper sym_dumper(writer());
1730 SymbolTable::oops_do(&sym_dumper);
1732 // write HPROF_LOAD_CLASS records
1733 SystemDictionary::classes_do(&do_load_class);
1734 Universe::basic_type_classes_do(&do_load_class);
1736 // write HPROF_FRAME and HPROF_TRACE records
1737 // this must be called after _klass_map is built when iterating the classes above.
1738 dump_stack_traces();
1740 // write HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT
1741 write_dump_header();
1743 // Writes HPROF_GC_CLASS_DUMP records
1744 SystemDictionary::classes_do(&do_class_dump);
1745 Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
1746 check_segment_length();
1748 // writes HPROF_GC_INSTANCE_DUMP records.
1749 // After each sub-record is written check_segment_length will be invoked. When
1750 // generated a segmented heap dump this allows us to check if the current
1751 // segment exceeds a threshold and if so, then a new segment is started.
1752 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
1753 // of the heap dump.
1754 HeapObjectDumper obj_dumper(this, writer());
1755 Universe::heap()->safe_object_iterate(&obj_dumper);
1757 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
1758 do_threads();
1759 check_segment_length();
1761 // HPROF_GC_ROOT_MONITOR_USED
1762 MonitorUsedDumper mon_dumper(writer());
1763 ObjectSynchronizer::oops_do(&mon_dumper);
1764 check_segment_length();
1766 // HPROF_GC_ROOT_JNI_GLOBAL
1767 JNIGlobalsDumper jni_dumper(writer());
1768 JNIHandles::oops_do(&jni_dumper);
1769 check_segment_length();
1771 // HPROF_GC_ROOT_STICKY_CLASS
1772 StickyClassDumper class_dumper(writer());
1773 SystemDictionary::always_strong_oops_do(&class_dumper);
1775 // fixes up the length of the dump record. In the case of a segmented
1776 // heap then the HPROF_HEAP_DUMP_END record is also written.
1777 end_of_dump();
1779 // Now we clear the global variables, so that a future dumper might run.
1780 clear_global_dumper();
1781 clear_global_writer();
1782 }
1784 void VM_HeapDumper::dump_stack_traces() {
1785 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
1786 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
1787 writer()->write_u4((u4) STACK_TRACE_ID);
1788 writer()->write_u4(0); // thread number
1789 writer()->write_u4(0); // frame count
1791 _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads());
1792 int frame_serial_num = 0;
1793 for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) {
1794 oop threadObj = thread->threadObj();
1795 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
1796 // dump thread stack trace
1797 ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
1798 stack_trace->dump_stack_at_safepoint(-1);
1799 _stack_traces[_num_threads++] = stack_trace;
1801 // write HPROF_FRAME records for this thread's stack trace
1802 int depth = stack_trace->get_stack_depth();
1803 int thread_frame_start = frame_serial_num;
1804 int extra_frames = 0;
1805 // write fake frame that makes it look like the thread, which caused OOME,
1806 // is in the OutOfMemoryError zero-parameter constructor
1807 if (thread == _oome_thread && _oome_constructor != NULL) {
1808 int oome_serial_num = _klass_map->find(Klass::cast(_oome_constructor->method_holder()));
1809 // the class serial number starts from 1
1810 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
1811 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
1812 _oome_constructor, 0);
1813 extra_frames++;
1814 }
1815 for (int j=0; j < depth; j++) {
1816 StackFrameInfo* frame = stack_trace->stack_frame_at(j);
1817 methodOop m = frame->method();
1818 int class_serial_num = _klass_map->find(Klass::cast(m->method_holder()));
1819 // the class serial number starts from 1
1820 assert(class_serial_num > 0, "class not found");
1821 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
1822 }
1823 depth += extra_frames;
1825 // write HPROF_TRACE record for one thread
1826 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
1827 int stack_serial_num = _num_threads + STACK_TRACE_ID;
1828 writer()->write_u4(stack_serial_num); // stack trace serial number
1829 writer()->write_u4((u4) _num_threads); // thread serial number
1830 writer()->write_u4(depth); // frame count
1831 for (int j=1; j <= depth; j++) {
1832 writer()->write_id(thread_frame_start + j);
1833 }
1834 }
1835 }
1836 }
1838 // dump the heap to given path.
1839 int HeapDumper::dump(const char* path) {
1840 assert(path != NULL && strlen(path) > 0, "path missing");
1842 // print message in interactive case
1843 if (print_to_tty()) {
1844 tty->print_cr("Dumping heap to %s ...", path);
1845 timer()->start();
1846 }
1848 // create the dump writer. If the file can be opened then bail
1849 DumpWriter writer(path);
1850 if (!writer.is_open()) {
1851 set_error(writer.error());
1852 if (print_to_tty()) {
1853 tty->print_cr("Unable to create %s: %s", path,
1854 (error() != NULL) ? error() : "reason unknown");
1855 }
1856 return -1;
1857 }
1859 // generate the dump
1860 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
1861 if (Thread::current()->is_VM_thread()) {
1862 assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
1863 dumper.doit();
1864 } else {
1865 VMThread::execute(&dumper);
1866 }
1868 // close dump file and record any error that the writer may have encountered
1869 writer.close();
1870 set_error(writer.error());
1872 // print message in interactive case
1873 if (print_to_tty()) {
1874 timer()->stop();
1875 if (error() == NULL) {
1876 char msg[256];
1877 sprintf(msg, "Heap dump file created [%s bytes in %3.3f secs]",
1878 os::jlong_format_specifier(), timer()->seconds());
1879 tty->print_cr(msg, writer.bytes_written());
1880 } else {
1881 tty->print_cr("Dump file is incomplete: %s", writer.error());
1882 }
1883 }
1885 return (writer.error() == NULL) ? 0 : -1;
1886 }
1888 // stop timer (if still active), and free any error string we might be holding
1889 HeapDumper::~HeapDumper() {
1890 if (timer()->is_active()) {
1891 timer()->stop();
1892 }
1893 set_error(NULL);
1894 }
1897 // returns the error string (resource allocated), or NULL
1898 char* HeapDumper::error_as_C_string() const {
1899 if (error() != NULL) {
1900 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
1901 strcpy(str, error());
1902 return str;
1903 } else {
1904 return NULL;
1905 }
1906 }
1908 // set the error string
1909 void HeapDumper::set_error(char* error) {
1910 if (_error != NULL) {
1911 os::free(_error);
1912 }
1913 if (error == NULL) {
1914 _error = NULL;
1915 } else {
1916 _error = os::strdup(error);
1917 assert(_error != NULL, "allocation failure");
1918 }
1919 }
1921 // Called by out-of-memory error reporting by a single Java thread
1922 // outside of a JVM safepoint
1923 void HeapDumper::dump_heap_from_oome() {
1924 HeapDumper::dump_heap(true);
1925 }
1927 // Called by error reporting by a single Java thread outside of a JVM safepoint,
1928 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
1929 // callers are strictly serialized and guaranteed not to interfere below. For more
1930 // general use, however, this method will need modification to prevent
1931 // inteference when updating the static variables base_path and dump_file_seq below.
1932 void HeapDumper::dump_heap() {
1933 HeapDumper::dump_heap(false);
1934 }
1936 void HeapDumper::dump_heap(bool oome) {
1937 static char base_path[JVM_MAXPATHLEN] = {'\0'};
1938 static uint dump_file_seq = 0;
1939 char* my_path;
1940 const int max_digit_chars = 20;
1942 const char* dump_file_name = "java_pid";
1943 const char* dump_file_ext = ".hprof";
1945 // The dump file defaults to java_pid<pid>.hprof in the current working
1946 // directory. HeapDumpPath=<file> can be used to specify an alternative
1947 // dump file name or a directory where dump file is created.
1948 if (dump_file_seq == 0) { // first time in, we initialize base_path
1949 // Calculate potentially longest base path and check if we have enough
1950 // allocated statically.
1951 const size_t total_length =
1952 (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
1953 strlen(os::file_separator()) + max_digit_chars +
1954 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
1955 if (total_length > sizeof(base_path)) {
1956 warning("Cannot create heap dump file. HeapDumpPath is too long.");
1957 return;
1958 }
1960 bool use_default_filename = true;
1961 if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
1962 // HeapDumpPath=<file> not specified
1963 } else {
1964 strncpy(base_path, HeapDumpPath, sizeof(base_path));
1965 // check if the path is a directory (must exist)
1966 DIR* dir = os::opendir(base_path);
1967 if (dir == NULL) {
1968 use_default_filename = false;
1969 } else {
1970 // HeapDumpPath specified a directory. We append a file separator
1971 // (if needed).
1972 os::closedir(dir);
1973 size_t fs_len = strlen(os::file_separator());
1974 if (strlen(base_path) >= fs_len) {
1975 char* end = base_path;
1976 end += (strlen(base_path) - fs_len);
1977 if (strcmp(end, os::file_separator()) != 0) {
1978 strcat(base_path, os::file_separator());
1979 }
1980 }
1981 }
1982 }
1983 // If HeapDumpPath wasn't a file name then we append the default name
1984 if (use_default_filename) {
1985 const size_t dlen = strlen(base_path); // if heap dump dir specified
1986 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
1987 dump_file_name, os::current_process_id(), dump_file_ext);
1988 }
1989 const size_t len = strlen(base_path) + 1;
1990 my_path = (char*)os::malloc(len);
1991 if (my_path == NULL) {
1992 warning("Cannot create heap dump file. Out of system memory.");
1993 return;
1994 }
1995 strncpy(my_path, base_path, len);
1996 } else {
1997 // Append a sequence number id for dumps following the first
1998 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
1999 my_path = (char*)os::malloc(len);
2000 if (my_path == NULL) {
2001 warning("Cannot create heap dump file. Out of system memory.");
2002 return;
2003 }
2004 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
2005 }
2006 dump_file_seq++; // increment seq number for next time we dump
2008 HeapDumper dumper(false /* no GC before heap dump */,
2009 true /* send to tty */,
2010 oome /* pass along out-of-memory-error flag */);
2011 dumper.dump(my_path);
2012 os::free(my_path);
2013 }