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