1 /*
2 * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "classfile/classLoaderData.inline.hpp"
28 #include "classfile/classLoaderDataGraph.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "gc/shared/workgroup.hpp"
36 #include "jfr/jfrEvents.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "memory/universe.hpp"
40 #include "oops/objArrayKlass.hpp"
41 #include "oops/objArrayOop.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/typeArrayOop.inline.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/jniHandles.hpp"
48 #include "runtime/os.inline.hpp"
49 #include "runtime/reflectionUtils.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "runtime/threadSMR.hpp"
52 #include "runtime/vframe.hpp"
53 #include "runtime/vmThread.hpp"
54 #include "runtime/vmOperations.hpp"
55 #include "services/heapDumper.hpp"
56 #include "services/threadService.hpp"
57 #include "utilities/macros.hpp"
58 #include "utilities/ostream.hpp"
59
60 /*
61 * HPROF binary format - description copied from:
62 * src/share/demo/jvmti/hprof/hprof_io.c
63 *
64 *
65 * header "JAVA PROFILE 1.0.2" (0-terminated)
66 *
67 * u4 size of identifiers. Identifiers are used to represent
68 * UTF8 strings, objects, stack traces, etc. They usually
69 * have the same size as host pointers. For example, on
70 * Solaris and Win32, the size is 4.
71 * u4 high word
72 * u4 low word number of milliseconds since 0:00 GMT, 1/1/70
73 * [record]* a sequence of records.
74 *
75 *
76 * Record format:
77 *
78 * u1 a TAG denoting the type of the record
79 * u4 number of *microseconds* since the time stamp in the
80 * header. (wraps around in a little more than an hour)
81 * u4 number of bytes *remaining* in the record. Note that
82 * this number excludes the tag and the length field itself.
83 * [u1]* BODY of the record (a sequence of bytes)
84 *
85 *
86 * The following TAGs are supported:
87 *
88 * TAG BODY notes
89 *----------------------------------------------------------
90 * HPROF_UTF8 a UTF8-encoded name
91 *
92 * id name ID
93 * [u1]* UTF8 characters (no trailing zero)
94 *
95 * HPROF_LOAD_CLASS a newly loaded class
96 *
97 * u4 class serial number (> 0)
98 * id class object ID
99 * u4 stack trace serial number
100 * id class name ID
101 *
102 * HPROF_UNLOAD_CLASS an unloading class
103 *
104 * u4 class serial_number
105 *
106 * HPROF_FRAME a Java stack frame
107 *
108 * id stack frame ID
109 * id method name ID
110 * id method signature ID
111 * id source file name ID
112 * u4 class serial number
113 * i4 line number. >0: normal
114 * -1: unknown
115 * -2: compiled method
116 * -3: native method
117 *
118 * HPROF_TRACE a Java stack trace
119 *
120 * u4 stack trace serial number
121 * u4 thread serial number
122 * u4 number of frames
123 * [id]* stack frame IDs
124 *
125 *
126 * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC
127 *
128 * u2 flags 0x0001: incremental vs. complete
129 * 0x0002: sorted by allocation vs. live
130 * 0x0004: whether to force a GC
131 * u4 cutoff ratio
132 * u4 total live bytes
133 * u4 total live instances
134 * u8 total bytes allocated
135 * u8 total instances allocated
136 * u4 number of sites that follow
137 * [u1 is_array: 0: normal object
138 * 2: object array
139 * 4: boolean array
140 * 5: char array
141 * 6: float array
142 * 7: double array
143 * 8: byte array
144 * 9: short array
145 * 10: int array
146 * 11: long array
147 * u4 class serial number (may be zero during startup)
148 * u4 stack trace serial number
149 * u4 number of bytes alive
150 * u4 number of instances alive
151 * u4 number of bytes allocated
152 * u4]* number of instance allocated
153 *
154 * HPROF_START_THREAD a newly started thread.
155 *
156 * u4 thread serial number (> 0)
157 * id thread object ID
158 * u4 stack trace serial number
159 * id thread name ID
160 * id thread group name ID
161 * id thread group parent name ID
162 *
163 * HPROF_END_THREAD a terminating thread.
164 *
165 * u4 thread serial number
166 *
167 * HPROF_HEAP_SUMMARY heap summary
168 *
169 * u4 total live bytes
170 * u4 total live instances
171 * u8 total bytes allocated
172 * u8 total instances allocated
173 *
174 * HPROF_HEAP_DUMP denote a heap dump
175 *
176 * [heap dump sub-records]*
177 *
178 * There are four kinds of heap dump sub-records:
179 *
180 * u1 sub-record type
181 *
182 * HPROF_GC_ROOT_UNKNOWN unknown root
183 *
184 * id object ID
185 *
186 * HPROF_GC_ROOT_THREAD_OBJ thread object
187 *
188 * id thread object ID (may be 0 for a
189 * thread newly attached through JNI)
190 * u4 thread sequence number
191 * u4 stack trace sequence number
192 *
193 * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root
194 *
195 * id object ID
196 * id JNI global ref ID
197 *
198 * HPROF_GC_ROOT_JNI_LOCAL JNI local ref
199 *
200 * id object ID
201 * u4 thread serial number
202 * u4 frame # in stack trace (-1 for empty)
203 *
204 * HPROF_GC_ROOT_JAVA_FRAME Java stack frame
205 *
206 * id object ID
207 * u4 thread serial number
208 * u4 frame # in stack trace (-1 for empty)
209 *
210 * HPROF_GC_ROOT_NATIVE_STACK Native stack
211 *
212 * id object ID
213 * u4 thread serial number
214 *
215 * HPROF_GC_ROOT_STICKY_CLASS System class
216 *
217 * id object ID
218 *
219 * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block
220 *
221 * id object ID
222 * u4 thread serial number
223 *
224 * HPROF_GC_ROOT_MONITOR_USED Busy monitor
225 *
226 * id object ID
227 *
228 * HPROF_GC_CLASS_DUMP dump of a class object
229 *
230 * id class object ID
231 * u4 stack trace serial number
232 * id super class object ID
233 * id class loader object ID
234 * id signers object ID
235 * id protection domain object ID
236 * id reserved
237 * id reserved
238 *
239 * u4 instance size (in bytes)
240 *
241 * u2 size of constant pool
242 * [u2, constant pool index,
243 * ty, type
244 * 2: object
245 * 4: boolean
246 * 5: char
247 * 6: float
248 * 7: double
249 * 8: byte
250 * 9: short
251 * 10: int
252 * 11: long
253 * vl]* and value
254 *
255 * u2 number of static fields
256 * [id, static field name,
257 * ty, type,
258 * vl]* and value
259 *
260 * u2 number of inst. fields (not inc. super)
261 * [id, instance field name,
262 * ty]* type
263 *
264 * HPROF_GC_INSTANCE_DUMP dump of a normal object
265 *
266 * id object ID
267 * u4 stack trace serial number
268 * id class object ID
269 * u4 number of bytes that follow
270 * [vl]* instance field values (class, followed
271 * by super, super's super ...)
272 *
273 * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array
274 *
275 * id array object ID
276 * u4 stack trace serial number
277 * u4 number of elements
278 * id array class ID
279 * [id]* elements
280 *
281 * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array
282 *
283 * id array object ID
284 * u4 stack trace serial number
285 * u4 number of elements
286 * u1 element type
287 * 4: boolean array
288 * 5: char array
289 * 6: float array
290 * 7: double array
291 * 8: byte array
292 * 9: short array
293 * 10: int array
294 * 11: long array
295 * [u1]* elements
296 *
297 * HPROF_CPU_SAMPLES a set of sample traces of running threads
298 *
299 * u4 total number of samples
300 * u4 # of traces
301 * [u4 # of samples
302 * u4]* stack trace serial number
303 *
304 * HPROF_CONTROL_SETTINGS the settings of on/off switches
305 *
306 * u4 0x00000001: alloc traces on/off
307 * 0x00000002: cpu sampling on/off
308 * u2 stack trace depth
309 *
310 *
311 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
312 * be generated as a sequence of heap dump segments. This sequence is
313 * terminated by an end record. The additional tags allowed by format
314 * "JAVA PROFILE 1.0.2" are:
315 *
316 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
317 *
318 * [heap dump sub-records]*
319 * The same sub-record types allowed by HPROF_HEAP_DUMP
320 *
321 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
322 *
323 */
324
325
326 // HPROF tags
327
328 typedef enum {
329 // top-level records
330 HPROF_UTF8 = 0x01,
331 HPROF_LOAD_CLASS = 0x02,
332 HPROF_UNLOAD_CLASS = 0x03,
333 HPROF_FRAME = 0x04,
334 HPROF_TRACE = 0x05,
335 HPROF_ALLOC_SITES = 0x06,
336 HPROF_HEAP_SUMMARY = 0x07,
337 HPROF_START_THREAD = 0x0A,
338 HPROF_END_THREAD = 0x0B,
339 HPROF_HEAP_DUMP = 0x0C,
340 HPROF_CPU_SAMPLES = 0x0D,
341 HPROF_CONTROL_SETTINGS = 0x0E,
342
343 // 1.0.2 record types
344 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
345 HPROF_HEAP_DUMP_END = 0x2C,
346
347 // field types
348 HPROF_ARRAY_OBJECT = 0x01,
349 HPROF_NORMAL_OBJECT = 0x02,
350 HPROF_BOOLEAN = 0x04,
351 HPROF_CHAR = 0x05,
352 HPROF_FLOAT = 0x06,
353 HPROF_DOUBLE = 0x07,
354 HPROF_BYTE = 0x08,
355 HPROF_SHORT = 0x09,
356 HPROF_INT = 0x0A,
357 HPROF_LONG = 0x0B,
358
359 // data-dump sub-records
360 HPROF_GC_ROOT_UNKNOWN = 0xFF,
361 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
362 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
363 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
364 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
365 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
366 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
367 HPROF_GC_ROOT_MONITOR_USED = 0x07,
368 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
369 HPROF_GC_CLASS_DUMP = 0x20,
370 HPROF_GC_INSTANCE_DUMP = 0x21,
371 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
372 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
373 } hprofTag;
374
375 // Default stack trace ID (used for dummy HPROF_TRACE record)
376 enum {
377 STACK_TRACE_ID = 1,
378 INITIAL_CLASS_COUNT = 200
379 };
380
381 class GzipBackend;
382 class WriteWorkList;
383
384 // Interface for a compression implementation.
385 class AbstractCompressor : public CHeapObj<mtInternal> {
386 public:
387 virtual ~AbstractCompressor() { }
388
389 // Initialized the compressor. Return a static error message in case of an error.
390 // Otherwise it initized the needed out and tmp size for the given block size.
391 virtual char const* init(size_t block_size, size_t* needed_out_size, size_t* needed_tmp_size) = 0;
392
393 // Does the actual compression. Returns NULL on success and a static error message otherwise.
394 // Sets the 'compressed_size'.
395 virtual char const* compress(char* in, size_t in_size, char* out, size_t out_size, char* tmp, size_t tmp_size,
396 size_t* compressed_size) = 0;
397 };
398
399 // Interface for a writer implementation.
400 class AbstractWriter : public CHeapObj<mtInternal> {
401 public:
402 virtual ~AbstractWriter() { }
403
404 // Opens the writer. Returns NULL on success and a static error message otherwise.
405 virtual char const* open_writer() = 0;
406
407 // Does the write. Returns NULL on success and a static error message otherwise.
408 virtual char const* write_buf(char* buf, ssize_t size) = 0;
409 };
410
411
412 typedef char const* (*GzipInitFunc)(size_t, size_t*, size_t*, int);
413 typedef size_t(*GzipFunc)(char*, size_t, char*, size_t, char*, size_t, int, char*, char const**);
414
415 class GZipComressor : public AbstractCompressor {
416 private:
417 int _level;
418 size_t _block_size;
419 bool _is_first;
420
421 GzipInitFunc gzip_init_func;
422 GzipFunc gzip_func;
423
424 void* load_gzip_func(char const* name);
425
426 public:
427 GZipComressor(int level) : _level(level), _block_size(0), _is_first(false) {
428 }
429
430 virtual char const* init(size_t block_size, size_t* needed_out_size, size_t* needed_tmp_size);
431
432 virtual char const* compress(char* in, size_t in_size, char* out, size_t out_size, char* tmp, size_t tmp_size,
433 size_t* compressed_size);
434 };
435
436 void* GZipComressor::load_gzip_func(char const* name) {
437 char path[JVM_MAXPATHLEN];
438 char ebuf[1024];
439 void* handle;
440
441 if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "zip")) {
442 handle = os::dll_load(path, ebuf, sizeof ebuf);
443
444 if (handle != NULL) {
445 return os::dll_lookup(handle, name);
446 }
447 }
448
449 return NULL;
450 }
451
452 char const* GZipComressor::init(size_t block_size, size_t* needed_out_size, size_t* needed_tmp_size) {
453 _block_size = block_size;
454 _is_first = true;
455
456 gzip_func = (GzipFunc) load_gzip_func("ZIP_GZip_Fully");
457
458 if (gzip_func == NULL) {
459 return "Cannot get ZIP_GZip_Fully function";
460 } else {
461 gzip_init_func = (GzipInitFunc) load_gzip_func("ZIP_GZip_InitParams");
462
463 if (gzip_init_func == NULL) {
464 return "Cannot get ZIP_GZip_InitParams function";
465 } else {
466 return gzip_init_func(block_size, needed_out_size, needed_tmp_size, _level);
467 }
468 }
469 }
470
471 char const* GZipComressor::compress(char* in, size_t in_size, char* out, size_t out_size, char* tmp,
472 size_t tmp_size, size_t* compressed_size) {
473 char const* msg = NULL;
474
475 if (_is_first) {
476 char buf[128];
477 jio_snprintf(buf, sizeof(buf), "HPROF BLOCKSIZE=" SIZE_FORMAT, _block_size);
478 *compressed_size = gzip_func(in, in_size, out, out_size, tmp, tmp_size, _level, buf, &msg);
479 _is_first = false;
480 } else {
481 *compressed_size = gzip_func(in, in_size, out, out_size, tmp, tmp_size, _level, NULL, &msg);
482 }
483
484 return msg;
485 }
486
487
488 // A writer for a file.
489 class FileWriter : public AbstractWriter {
490 private:
491 char const* _path;
492 int _fd;
493
494 public:
495 FileWriter(char const* path) : _path(path), _fd(-1) { }
496
497 ~FileWriter();
498
499 // Opens the writer. Returns NULL on success and a static error message otherwise.
500 virtual char const* open_writer();
501
502 // Does the write. Returns NULL on success and a static error message otherwise.
503 virtual char const* write_buf(char* buf, ssize_t size);
504 };
505
506 char const* FileWriter::open_writer() {
507 assert(_fd < 0, "Must not already be open");
508
509 _fd = os::create_binary_file(_path, false); // don't replace existing file
510
511 if (_fd < 0) {
512 return os::strerror(errno);
513 }
514
515 return NULL;
516 }
517
518 FileWriter::~FileWriter() {
519 if (_fd >= 0) {
520 os::close(_fd);
521 _fd = -1;
522 }
523 }
524
525 char const* FileWriter::write_buf(char* buf, ssize_t size) {
526 assert(_fd >= 0, "Must be open");
527 assert(size > 0, "Must write at least one byte");
528
529 ssize_t n = (ssize_t) os::write(_fd, buf, (uint) size);
530
531 if (n <= 0) {
532 return os::strerror(errno);
533 }
534
535 return NULL;
536 }
537
538 // The data needed to write a single buffer (and compress it optionally).
539 struct WriteWork {
540 // The id of the work.
541 int64_t id;
542
543 // The input buffer where the raw data is
544 char* in;
545 size_t in_used;
546 size_t in_max;
547
548 // The output buffer where the compressed data is. Is NULL when compression is disabled.
549 char* out;
550 size_t out_used;
551 size_t out_max;
552
553 // The temporary space needed for compression. Is NULL when compression is disabled.
554 char* tmp;
555 size_t tmp_max;
556
557 // Used to link works into lists.
558 WriteWork* _next;
559 WriteWork* _prev;
560 };
561
562 // A list for works.
563 class WorkList {
564 private:
565 WriteWork _head;
566
567 void insert(WriteWork* before, WriteWork* work);
568 WriteWork* remove(WriteWork* work);
569
570 public:
571 WorkList();
572
573 // Return true if the list is empty.
574 bool is_empty() { return _head._next == &_head; }
575
576 // Adds to the beginning of the list.
577 void add_first(WriteWork* work) { insert(&_head, work); }
578
579 // Adds to the end of the list.
580 void add_last(WriteWork* work) { insert(_head._prev, work); }
581
582 // Adds so the ids are ordered.
583 void add_by_id(WriteWork* work);
584
585 // Returns the first element.
586 WriteWork* first() { return is_empty() ? NULL : _head._next; }
587
588 // Returns the last element.
589 WriteWork* last() { return is_empty() ? NULL : _head._prev; }
590
591 // Removes the first element. Returns NULL is empty.
592 WriteWork* remove_first() { return remove(first()); }
593
594 // Removes the last element. Returns NULL is empty.
595 WriteWork* remove_last() { return remove(first()); }
596 };
597
598 WorkList::WorkList() {
599 _head._next = &_head;
600 _head._prev = &_head;
601 }
602
603 void WorkList::insert(WriteWork* before, WriteWork* work) {
604 work->_prev = before;
605 work->_next = before->_next;
606 before->_next = work;
607 work->_next->_prev = work;
608 }
609
610 WriteWork* WorkList::remove(WriteWork* work) {
611 if (work != NULL) {
612 assert(work->_next != work, "Invalid next");
613 assert(work->_prev != work, "Invalid prev");
614 work->_prev->_next = work->_next;;
615 work->_next->_prev = work->_prev;
616 work->_next = NULL;
617 work->_prev = NULL;
618 }
619
620 return work;
621 }
622
623 void WorkList::add_by_id(WriteWork* work) {
624 if (is_empty()) {
625 add_first(work);
626 } else {
627 WriteWork* last_curr = &_head;
628 WriteWork* curr = _head._next;
629
630 while (curr->id < work->id) {
631 last_curr = curr;
632 curr = curr->_next;
633
634 if (curr == &_head) {
635 add_last(work);
636 return;
637 }
638 }
639
640 insert(last_curr, work);
641 }
642 }
643
644 // The backend used to write data (and optionally compress it).
645 class CompressionBackend : StackObj {
646 bool _active;
647 char const * _err;
648
649 int _nr_of_threads;
650 int _works_created;
651 bool _work_creation_failed;
652
653 int64_t _id_to_write;
654 int64_t _next_id;
655
656 size_t _in_size;
657 size_t _max_waste;
658 size_t _out_size;
659 size_t _tmp_size;
660
661 size_t _written;
662
663 AbstractWriter* _writer;
664 AbstractCompressor* _compressor;
665
666 Monitor* _lock;
667
668 WriteWork* _current;
669 WorkList _to_compress;
670 WorkList _unused;
671 WorkList _finished;
672
673 void set_error(char const* new_error);
674
675 WriteWork* allocate_work(size_t in_size, size_t out_size, size_t tmp_size);
676 void free_work(WriteWork* work);
677 void free_work_list(WorkList* list);
678
679 WriteWork* get_work();
680 void do_compress(WriteWork* work);
681 void finish_work(WriteWork* work);
682
683 public:
684 // compressor can be NULL if no compression is used.
685 // Takes ownership of the writer and compressor.
686 // block_size is the buffer size of a WriteWork.
687 // max_waste is the maxiumum number of bytes to leave
688 // empty in the buffer when it is written.
689 CompressionBackend(AbstractWriter* writer, AbstractCompressor* compressor,
690 size_t block_size, size_t max_waste);
691
692 ~CompressionBackend();
693
694 size_t get_written() const { return _written; }
695
696 char const* error() const { return _err; }
697
698 // Commits the old buffer and sets up a new one.
699 void get_new_buffer(char** buffer, size_t* used, size_t* max);
700
701 // The entry point for a worker thread. If single_run is true, we only handle one work entry.
702 void thread_loop(bool single_run);
703
704 // Shuts down the backend, releasing all threads.
705 void deactivate();
706 };
707
708 CompressionBackend::CompressionBackend(AbstractWriter* writer, AbstractCompressor* compressor,
709 size_t block_size, size_t max_waste) :
710 _active(false),
711 _err(NULL),
712 _nr_of_threads(0),
713 _works_created(0),
714 _work_creation_failed(false),
715 _id_to_write(0),
716 _next_id(0),
717 _in_size(block_size),
718 _max_waste(max_waste),
719 _out_size(0),
720 _tmp_size(0),
721 _written(0),
722 _writer(writer),
723 _compressor(compressor),
724 _lock(new (std::nothrow) PaddedMonitor(Mutex::leaf, "HProf Compression Backend",
725 true, Mutex::_safepoint_check_never)) {
726 if (_writer == NULL) {
727 set_error("Could not allocate writer");
728 } else if (_lock == NULL) {
729 set_error("Could not allocate lock");
730 } else {
731 set_error(_writer->open_writer());
732 }
733
734 if (_compressor != NULL) {
735 set_error(_compressor->init(_in_size, &_out_size, &_tmp_size));
736 }
737
738 _current = allocate_work(_in_size, _out_size, _tmp_size);
739
740 if (_current == NULL) {
741 set_error("Could not allocate memory for buffer");
742 }
743
744 _active = (_err == NULL);
745 }
746
747 CompressionBackend::~CompressionBackend() {
748 assert(!_active, "Must not be active by now");
749 assert(_nr_of_threads == 0, "Must have no active threads");
750 assert(_to_compress.is_empty() && _finished.is_empty(), "Still work to do");
751
752 free_work_list(&_unused);
753 free_work(_current);
754 assert(_works_created == 0, "All work must have been freed");
755
756 delete _compressor;
757 delete _writer;
758 delete _lock;
759 }
760
761 void CompressionBackend::deactivate() {
762 assert(_active, "Must be active");
763
764 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
765
766 // Make sure we write a partially filled buffer.
767 if ((_current != NULL) && (_current->in_used > 0)) {
768 _current->id = _next_id++;
769 _to_compress.add_last(_current);
770 _current = NULL;
771 ml.notify_all();
772 }
773
774 // Wait for the threads to drain the compression work list.
775 while (!_to_compress.is_empty()) {
776 // If we have no threads, compress the current one itself.
777 if (_nr_of_threads == 0) {
778 MutexUnlocker mu(_lock, Mutex::_no_safepoint_check_flag);
779 thread_loop(true);
780 } else {
781 ml.wait();
782 }
783 }
784
785 _active = false;
786 ml.notify_all();
787 }
788
789 void CompressionBackend::thread_loop(bool single_run) {
790 // Register if this is a worker thread.
791 if (!single_run) {
792 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
793 _nr_of_threads++;
794 }
795
796 while (true) {
797 WriteWork* work = get_work();
798
799 if (work == NULL) {
800 assert(!single_run, "Should never happen for single thread");
801 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
802 _nr_of_threads--;
803 assert(_nr_of_threads >= 0, "Too many threads finished");
804 ml.notify_all();
805
806 return;
807 } else {
808 do_compress(work);
809 finish_work(work);
810 }
811
812 if (single_run) {
813 return;
814 }
815 }
816 }
817
818 void CompressionBackend::set_error(char const* new_error) {
819 if ((new_error != NULL) && (_err == NULL)) {
820 _err = new_error;
821 }
822 }
823
824 WriteWork* CompressionBackend::allocate_work(size_t in_size, size_t out_size, size_t tmp_size) {
825 WriteWork* result = (WriteWork*) os::malloc(sizeof(WriteWork), mtInternal);
826
827 if (result == NULL) {
828 _work_creation_failed = true;
829 return NULL;
830 }
831
832 _works_created++;
833 result->in = (char*) os::malloc(in_size, mtInternal);
834 result->in_max = in_size;
835 result->in_used = 0;
836 result->out = NULL;
837 result->tmp = NULL;
838
839 if (result->in == NULL) {
840 goto fail;
841 }
842
843 if (out_size > 0) {
844 result->out = (char*) os::malloc(out_size, mtInternal);
845 result->out_used = 0;
846 result->out_max = out_size;
847
848 if (result->out == NULL) {
849 goto fail;
850 }
851 }
852
853 if (tmp_size > 0) {
854 result->tmp = (char*) os::malloc(tmp_size, mtInternal);
855 result->tmp_max = tmp_size;
856
857 if (result->tmp == NULL) {
858 goto fail;
859 }
860 }
861
862 return result;
863
864 fail:
865 free_work(result);
866 _work_creation_failed = true;
867 return NULL;
868 }
869
870 void CompressionBackend::free_work(WriteWork* work) {
871 if (work != NULL) {
872 os::free(work->in);
873 os::free(work->out);
874 os::free(work->tmp);
875 os::free(work);
876 --_works_created;
877 }
878 }
879
880 void CompressionBackend::free_work_list(WorkList* list) {
881 while (!list->is_empty()) {
882 free_work(list->remove_first());
883 }
884 }
885
886 WriteWork* CompressionBackend::get_work() {
887 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
888
889 while (_active && _to_compress.is_empty()) {
890 ml.wait();
891 }
892
893 return _to_compress.remove_first();
894 }
895
896 void CompressionBackend::get_new_buffer(char** buffer, size_t* used, size_t* max) {
897 if (_active) {
898 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
899
900 if (*used > 0) {
901 _current->in_used += *used;
902
903 // Check if we don not waste more than _max_waste. If yes, write the buffer.
904 // Otherwise return the rest of the buffer as the new buffer.
905 if (_current->in_max - _current->in_used <= _max_waste) {
906 _current->id = _next_id++;
907 _to_compress.add_last(_current);
908 _current = NULL;
909 ml.notify_all();
910 } else {
911 *buffer = _current->in + _current->in_used;
912 *used = 0;
913 *max = _current->in_max - _current->in_used;
914
915 return;
916 }
917 }
918
919 while ((_current == NULL) && _unused.is_empty() && _active) {
920 // Add more work objects if needed.
921 if (!_work_creation_failed && (_works_created <= _nr_of_threads)) {
922 WriteWork* work = allocate_work(_in_size, _out_size, _tmp_size);
923
924 if (work != NULL) {
925 _unused.add_first(work);
926 }
927 } else if (!_to_compress.is_empty() && (_nr_of_threads == 0)) {
928 // If we have no threads, compress the current one itself.
929 MutexUnlocker mu(_lock, Mutex::_no_safepoint_check_flag);
930 thread_loop(true);
931 } else {
932 ml.wait();
933 }
934 }
935
936 if (_current == NULL) {
937 _current = _unused.remove_first();
938 }
939
940 if (_current != NULL) {
941 _current->in_used = 0;
942 _current->out_used = 0;
943 *buffer = _current->in;
944 *used = 0;
945 *max = _current->in_max;
946
947 return;
948 }
949 }
950
951 *buffer = NULL;
952 *used = 0;
953 *max = 0;
954
955 return;
956 }
957
958 void CompressionBackend::do_compress(WriteWork* work) {
959 if (_compressor != NULL) {
960 char const* msg = _compressor->compress(work->in, work->in_used, work->out, work->out_max,
961 work->tmp, _tmp_size, &work->out_used);
962
963 if (msg != NULL) {
964 MutexLocker ml(_lock, Mutex::_no_safepoint_check_flag);
965 set_error(msg);
966 }
967 }
968 }
969
970 void CompressionBackend::finish_work(WriteWork* work) {
971 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
972
973 _finished.add_by_id(work);
974
975 // Write all finished works as far as we can.
976 while (!_finished.is_empty() && (_finished.first()->id == _id_to_write)) {
977 WriteWork* to_write = _finished.remove_first();
978 size_t left = _compressor == NULL ? to_write->in_used : to_write->out_used;
979 char* p = _compressor == NULL ? to_write->in : to_write->out;
980 char const* msg = NULL;
981
982 if (_err == NULL) {
983 _written += left;
984 MutexUnlocker mu(_lock, Mutex::_no_safepoint_check_flag);
985 msg = _writer->write_buf(p, (ssize_t) left);
986 }
987
988 set_error(msg);
989 _unused.add_first(to_write);
990 _id_to_write++;
991 }
992
993 ml.notify_all();
994 }
995
996
997 class DumpWriter : public StackObj {
998 private:
999 enum {
1000 io_buffer_max_size = 1*M,
1001 io_buffer_max_waste = 10*K,
1002 dump_segment_header_size = 9
1003 };
1004
1005 char* _buffer; // internal buffer
1006 size_t _size;
1007 size_t _pos;
1008
1009 bool _in_dump_segment; // Are we currently in a dump segment?
1010 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
1011 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
1012 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
1013
1014 CompressionBackend _backend; // Does the actual writing.
1015
1016 void flush();
1017
1018 char* buffer() const { return _buffer; }
1019 size_t buffer_size() const { return _size; }
1020 size_t position() const { return _pos; }
1021 void set_position(size_t pos) { _pos = pos; }
1022
1023 // Can be called if we have enough room in the buffer.
1024 void write_fast(void* s, size_t len);
1025
1026 // Returns true if we have enough room in the buffer for 'len' bytes.
1027 bool can_write_fast(size_t len);
1028
1029 public:
1030 // Takes ownership of the writer and compressor.
1031 DumpWriter(AbstractWriter* writer, AbstractCompressor* compressor);
1032
1033 ~DumpWriter();
1034
1035 // total number of bytes written to the disk
1036 julong bytes_written() const { return (julong) _backend.get_written(); }
1037
1038 char const* error() const { return _backend.error(); }
1039
1040 // writer functions
1041 void write_raw(void* s, size_t len);
1042 void write_u1(u1 x);
1043 void write_u2(u2 x);
1044 void write_u4(u4 x);
1045 void write_u8(u8 x);
1046 void write_objectID(oop o);
1047 void write_symbolID(Symbol* o);
1048 void write_classID(Klass* k);
1049 void write_id(u4 x);
1050
1051 // Start a new sub-record. Starts a new heap dump segment if needed.
1052 void start_sub_record(u1 tag, u4 len);
1053 // Ends the current sub-record.
1054 void end_sub_record();
1055 // Finishes the current dump segment if not already finished.
1056 void finish_dump_segment();
1057
1058 // Called by threads used for parallel writing.
1059 void writer_loop() { _backend.thread_loop(false); }
1060 // Called when finished to release the threads.
1061 void deactivate() { _backend.deactivate(); }
1062 };
1063
1064 DumpWriter::DumpWriter(AbstractWriter* writer, AbstractCompressor* compressor) :
1065 _buffer(NULL),
1066 _size(0),
1067 _pos(0),
1068 _in_dump_segment(false),
1069 _backend(writer, compressor, io_buffer_max_size, io_buffer_max_waste) {
1070 flush();
1071 }
1072
1073 DumpWriter::~DumpWriter() {
1074 flush();
1075 }
1076
1077 void DumpWriter::write_fast(void* s, size_t len) {
1078 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
1079 assert(buffer_size() - position() >= len, "Must fit");
1080 debug_only(_sub_record_left -= len);
1081
1082 memcpy(buffer() + position(), s, len);
1083 set_position(position() + len);
1084 }
1085
1086 bool DumpWriter::can_write_fast(size_t len) {
1087 return buffer_size() - position() >= len;
1088 }
1089
1090 // write raw bytes
1091 void DumpWriter::write_raw(void* s, size_t len) {
1092 assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
1093 debug_only(_sub_record_left -= len);
1094
1095 // flush buffer to make room.
1096 while (len > buffer_size() - position()) {
1097 assert(!_in_dump_segment || _is_huge_sub_record, "Cannot overflow in non-huge sub-record.");
1098
1099 size_t to_write = buffer_size() - position();
1100 memcpy(buffer() + position(), s, to_write);
1101 s = (void*) ((char*) s + to_write);
1102 len -= to_write;
1103 set_position(position() + to_write);
1104 flush();
1105 }
1106
1107 memcpy(buffer() + position(), s, len);
1108 set_position(position() + len);
1109 }
1110
1111 // flush any buffered bytes to the file
1112 void DumpWriter::flush() {
1113 _backend.get_new_buffer(&_buffer, &_pos, &_size);
1114 }
1115
1116 // Makes sure we inline the fast write into the write_u* functions. This is a big speedup.
1117 #define WRITE_KNOWN_TYPE(p, len) do { if (can_write_fast((len))) write_fast((p), (len)); \
1118 else write_raw((p), (len)); } while (0)
1119
1120 void DumpWriter::write_u1(u1 x) {
1121 WRITE_KNOWN_TYPE((void*) &x, 1);
1122 }
1123
1124 void DumpWriter::write_u2(u2 x) {
1125 u2 v;
1126 Bytes::put_Java_u2((address)&v, x);
1127 WRITE_KNOWN_TYPE((void*)&v, 2);
1128 }
1129
1130 void DumpWriter::write_u4(u4 x) {
1131 u4 v;
1132 Bytes::put_Java_u4((address)&v, x);
1133 WRITE_KNOWN_TYPE((void*)&v, 4);
1134 }
1135
1136 void DumpWriter::write_u8(u8 x) {
1137 u8 v;
1138 Bytes::put_Java_u8((address)&v, x);
1139 WRITE_KNOWN_TYPE((void*)&v, 8);
1140 }
1141
1142 void DumpWriter::write_objectID(oop o) {
1143 address a = cast_from_oop<address>(o);
1144 #ifdef _LP64
1145 write_u8((u8)a);
1146 #else
1147 write_u4((u4)a);
1148 #endif
1149 }
1150
1151 void DumpWriter::write_symbolID(Symbol* s) {
1152 address a = (address)((uintptr_t)s);
1153 #ifdef _LP64
1154 write_u8((u8)a);
1155 #else
1156 write_u4((u4)a);
1157 #endif
1158 }
1159
1160 void DumpWriter::write_id(u4 x) {
1161 #ifdef _LP64
1162 write_u8((u8) x);
1163 #else
1164 write_u4(x);
1165 #endif
1166 }
1167
1168 // We use java mirror as the class ID
1169 void DumpWriter::write_classID(Klass* k) {
1170 write_objectID(k->java_mirror());
1171 }
1172
1173 void DumpWriter::finish_dump_segment() {
1174 if (_in_dump_segment) {
1175 assert(_sub_record_left == 0, "Last sub-record not written completely");
1176 assert(_sub_record_ended, "sub-record must have ended");
1177
1178 // Fix up the dump segment length if we haven't written a huge sub-record last
1179 // (in which case the segment length was already set to the correct value initially).
1180 if (!_is_huge_sub_record) {
1181 assert(position() > dump_segment_header_size, "Dump segment should have some content");
1182 Bytes::put_Java_u4((address) (buffer() + 5), (u4) (position() - dump_segment_header_size));
1183 }
1184
1185 flush();
1186 _in_dump_segment = false;
1187 }
1188 }
1189
1190 void DumpWriter::start_sub_record(u1 tag, u4 len) {
1191 if (!_in_dump_segment) {
1192 if (position() > 0) {
1193 flush();
1194 }
1195
1196 assert(position() == 0, "Must be at the start");
1197
1198 write_u1(HPROF_HEAP_DUMP_SEGMENT);
1199 write_u4(0); // timestamp
1200 // Will be fixed up later if we add more sub-records. If this is a huge sub-record,
1201 // this is already the correct length, since we don't add more sub-records.
1202 write_u4(len);
1203 _in_dump_segment = true;
1204 _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
1205 } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
1206 // This object will not fit in completely or the last sub-record was huge.
1207 // Finish the current segement and try again.
1208 finish_dump_segment();
1209 start_sub_record(tag, len);
1210
1211 return;
1212 }
1213
1214 debug_only(_sub_record_left = len);
1215 debug_only(_sub_record_ended = false);
1216
1217 write_u1(tag);
1218 }
1219
1220 void DumpWriter::end_sub_record() {
1221 assert(_in_dump_segment, "must be in dump segment");
1222 assert(_sub_record_left == 0, "sub-record not written completely");
1223 assert(!_sub_record_ended, "Must not have ended yet");
1224 debug_only(_sub_record_ended = true);
1225 }
1226
1227 // Support class with a collection of functions used when dumping the heap
1228
1229 class DumperSupport : AllStatic {
1230 public:
1231
1232 // write a header of the given type
1233 static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
1234
1235 // returns hprof tag for the given type signature
1236 static hprofTag sig2tag(Symbol* sig);
1237 // returns hprof tag for the given basic type
1238 static hprofTag type2tag(BasicType type);
1239 // Returns the size of the data to write.
1240 static u4 sig2size(Symbol* sig);
1241
1242 // returns the size of the instance of the given class
1243 static u4 instance_size(Klass* k);
1244
1245 // dump a jfloat
1246 static void dump_float(DumpWriter* writer, jfloat f);
1247 // dump a jdouble
1248 static void dump_double(DumpWriter* writer, jdouble d);
1249 // dumps the raw value of the given field
1250 static void dump_field_value(DumpWriter* writer, char type, oop obj, int offset);
1251 // returns the size of the static fields; also counts the static fields
1252 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
1253 // dumps static fields of the given class
1254 static void dump_static_fields(DumpWriter* writer, Klass* k);
1255 // dump the raw values of the instance fields of the given object
1256 static void dump_instance_fields(DumpWriter* writer, oop o);
1257 // get the count of the instance fields for a given class
1258 static u2 get_instance_fields_count(InstanceKlass* ik);
1259 // dumps the definition of the instance fields for a given class
1260 static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k);
1261 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1262 static void dump_instance(DumpWriter* writer, oop o);
1263 // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
1264 // array classes
1265 static void dump_class_and_array_classes(DumpWriter* writer, Klass* k);
1266 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
1267 // class (and each multi-dimensional array class too)
1268 static void dump_basic_type_array_class(DumpWriter* writer, Klass* k);
1269
1270 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1271 static void dump_object_array(DumpWriter* writer, objArrayOop array);
1272 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1273 static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
1274 // create HPROF_FRAME record for the given method and bci
1275 static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
1276
1277 // check if we need to truncate an array
1278 static int calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size);
1279
1280 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
1281 static void end_of_dump(DumpWriter* writer);
1282
1283 static oop mask_dormant_archived_object(oop o) {
1284 if (o != NULL && o->klass()->java_mirror() == NULL) {
1285 // Ignore this object since the corresponding java mirror is not loaded.
1286 // Might be a dormant archive object.
1287 return NULL;
1288 } else {
1289 return o;
1290 }
1291 }
1292 };
1293
1294 // write a header of the given type
1295 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
1296 writer->write_u1((u1)tag);
1297 writer->write_u4(0); // current ticks
1298 writer->write_u4(len);
1299 }
1300
1301 // returns hprof tag for the given type signature
1302 hprofTag DumperSupport::sig2tag(Symbol* sig) {
1303 switch (sig->char_at(0)) {
1304 case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT;
1305 case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT;
1306 case JVM_SIGNATURE_BYTE : return HPROF_BYTE;
1307 case JVM_SIGNATURE_CHAR : return HPROF_CHAR;
1308 case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT;
1309 case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE;
1310 case JVM_SIGNATURE_INT : return HPROF_INT;
1311 case JVM_SIGNATURE_LONG : return HPROF_LONG;
1312 case JVM_SIGNATURE_SHORT : return HPROF_SHORT;
1313 case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN;
1314 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1315 }
1316 }
1317
1318 hprofTag DumperSupport::type2tag(BasicType type) {
1319 switch (type) {
1320 case T_BYTE : return HPROF_BYTE;
1321 case T_CHAR : return HPROF_CHAR;
1322 case T_FLOAT : return HPROF_FLOAT;
1323 case T_DOUBLE : return HPROF_DOUBLE;
1324 case T_INT : return HPROF_INT;
1325 case T_LONG : return HPROF_LONG;
1326 case T_SHORT : return HPROF_SHORT;
1327 case T_BOOLEAN : return HPROF_BOOLEAN;
1328 default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
1329 }
1330 }
1331
1332 u4 DumperSupport::sig2size(Symbol* sig) {
1333 switch (sig->char_at(0)) {
1334 case JVM_SIGNATURE_CLASS:
1335 case JVM_SIGNATURE_ARRAY: return sizeof(address);
1336 case JVM_SIGNATURE_BOOLEAN:
1337 case JVM_SIGNATURE_BYTE: return 1;
1338 case JVM_SIGNATURE_SHORT:
1339 case JVM_SIGNATURE_CHAR: return 2;
1340 case JVM_SIGNATURE_INT:
1341 case JVM_SIGNATURE_FLOAT: return 4;
1342 case JVM_SIGNATURE_LONG:
1343 case JVM_SIGNATURE_DOUBLE: return 8;
1344 default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
1345 }
1346 }
1347
1348 // dump a jfloat
1349 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
1350 if (g_isnan(f)) {
1351 writer->write_u4(0x7fc00000); // collapsing NaNs
1352 } else {
1353 union {
1354 int i;
1355 float f;
1356 } u;
1357 u.f = (float)f;
1358 writer->write_u4((u4)u.i);
1359 }
1360 }
1361
1362 // dump a jdouble
1363 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
1364 union {
1365 jlong l;
1366 double d;
1367 } u;
1368 if (g_isnan(d)) { // collapsing NaNs
1369 u.l = (jlong)(0x7ff80000);
1370 u.l = (u.l << 32);
1371 } else {
1372 u.d = (double)d;
1373 }
1374 writer->write_u8((u8)u.l);
1375 }
1376
1377 // dumps the raw value of the given field
1378 void DumperSupport::dump_field_value(DumpWriter* writer, char type, oop obj, int offset) {
1379 switch (type) {
1380 case JVM_SIGNATURE_CLASS :
1381 case JVM_SIGNATURE_ARRAY : {
1382 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
1383 if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
1384 ResourceMark rm;
1385 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1386 p2i(o), o->klass()->external_name(),
1387 p2i(obj), obj->klass()->external_name());
1388 }
1389 o = mask_dormant_archived_object(o);
1390 assert(oopDesc::is_oop_or_null(o), "Expected an oop or NULL at " PTR_FORMAT, p2i(o));
1391 writer->write_objectID(o);
1392 break;
1393 }
1394 case JVM_SIGNATURE_BYTE : {
1395 jbyte b = obj->byte_field(offset);
1396 writer->write_u1((u1)b);
1397 break;
1398 }
1399 case JVM_SIGNATURE_CHAR : {
1400 jchar c = obj->char_field(offset);
1401 writer->write_u2((u2)c);
1402 break;
1403 }
1404 case JVM_SIGNATURE_SHORT : {
1405 jshort s = obj->short_field(offset);
1406 writer->write_u2((u2)s);
1407 break;
1408 }
1409 case JVM_SIGNATURE_FLOAT : {
1410 jfloat f = obj->float_field(offset);
1411 dump_float(writer, f);
1412 break;
1413 }
1414 case JVM_SIGNATURE_DOUBLE : {
1415 jdouble d = obj->double_field(offset);
1416 dump_double(writer, d);
1417 break;
1418 }
1419 case JVM_SIGNATURE_INT : {
1420 jint i = obj->int_field(offset);
1421 writer->write_u4((u4)i);
1422 break;
1423 }
1424 case JVM_SIGNATURE_LONG : {
1425 jlong l = obj->long_field(offset);
1426 writer->write_u8((u8)l);
1427 break;
1428 }
1429 case JVM_SIGNATURE_BOOLEAN : {
1430 jboolean b = obj->bool_field(offset);
1431 writer->write_u1((u1)b);
1432 break;
1433 }
1434 default : {
1435 ShouldNotReachHere();
1436 break;
1437 }
1438 }
1439 }
1440
1441 // returns the size of the instance of the given class
1442 u4 DumperSupport::instance_size(Klass* k) {
1443 HandleMark hm;
1444 InstanceKlass* ik = InstanceKlass::cast(k);
1445 u4 size = 0;
1446
1447 for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
1448 if (!fld.access_flags().is_static()) {
1449 size += sig2size(fld.signature());
1450 }
1451 }
1452 return size;
1453 }
1454
1455 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1456 HandleMark hm;
1457 field_count = 0;
1458 u4 size = 0;
1459
1460 for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
1461 if (fldc.access_flags().is_static()) {
1462 field_count++;
1463 size += sig2size(fldc.signature());
1464 }
1465 }
1466
1467 // Add in resolved_references which is referenced by the cpCache
1468 // The resolved_references is an array per InstanceKlass holding the
1469 // strings and other oops resolved from the constant pool.
1470 oop resolved_references = ik->constants()->resolved_references_or_null();
1471 if (resolved_references != NULL) {
1472 field_count++;
1473 size += sizeof(address);
1474
1475 // Add in the resolved_references of the used previous versions of the class
1476 // in the case of RedefineClasses
1477 InstanceKlass* prev = ik->previous_versions();
1478 while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
1479 field_count++;
1480 size += sizeof(address);
1481 prev = prev->previous_versions();
1482 }
1483 }
1484
1485 // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0]
1486 // arrays.
1487 oop init_lock = ik->init_lock();
1488 if (init_lock != NULL) {
1489 field_count++;
1490 size += sizeof(address);
1491 }
1492
1493 // We write the value itself plus a name and a one byte type tag per field.
1494 return size + field_count * (sizeof(address) + 1);
1495 }
1496
1497 // dumps static fields of the given class
1498 void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) {
1499 HandleMark hm;
1500 InstanceKlass* ik = InstanceKlass::cast(k);
1501
1502 // dump the field descriptors and raw values
1503 for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
1504 if (fld.access_flags().is_static()) {
1505 Symbol* sig = fld.signature();
1506
1507 writer->write_symbolID(fld.name()); // name
1508 writer->write_u1(sig2tag(sig)); // type
1509
1510 // value
1511 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1512 }
1513 }
1514
1515 // Add resolved_references for each class that has them
1516 oop resolved_references = ik->constants()->resolved_references_or_null();
1517 if (resolved_references != NULL) {
1518 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1519 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1520 writer->write_objectID(resolved_references);
1521
1522 // Also write any previous versions
1523 InstanceKlass* prev = ik->previous_versions();
1524 while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
1525 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1526 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1527 writer->write_objectID(prev->constants()->resolved_references());
1528 prev = prev->previous_versions();
1529 }
1530 }
1531
1532 // Add init lock to the end if the class is not yet initialized
1533 oop init_lock = ik->init_lock();
1534 if (init_lock != NULL) {
1535 writer->write_symbolID(vmSymbols::init_lock_name()); // name
1536 writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type
1537 writer->write_objectID(init_lock);
1538 }
1539 }
1540
1541 // dump the raw values of the instance fields of the given object
1542 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
1543 HandleMark hm;
1544 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1545
1546 for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
1547 if (!fld.access_flags().is_static()) {
1548 Symbol* sig = fld.signature();
1549 dump_field_value(writer, sig->char_at(0), o, fld.offset());
1550 }
1551 }
1552 }
1553
1554 // dumps the definition of the instance fields for a given class
1555 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1556 HandleMark hm;
1557 u2 field_count = 0;
1558
1559 for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
1560 if (!fldc.access_flags().is_static()) field_count++;
1561 }
1562
1563 return field_count;
1564 }
1565
1566 // dumps the definition of the instance fields for a given class
1567 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) {
1568 HandleMark hm;
1569 InstanceKlass* ik = InstanceKlass::cast(k);
1570
1571 // dump the field descriptors
1572 for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
1573 if (!fld.access_flags().is_static()) {
1574 Symbol* sig = fld.signature();
1575
1576 writer->write_symbolID(fld.name()); // name
1577 writer->write_u1(sig2tag(sig)); // type
1578 }
1579 }
1580 }
1581
1582 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1583 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
1584 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1585 u4 is = instance_size(ik);
1586 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1587
1588 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1589 writer->write_objectID(o);
1590 writer->write_u4(STACK_TRACE_ID);
1591
1592 // class ID
1593 writer->write_classID(ik);
1594
1595 // number of bytes that follow
1596 writer->write_u4(is);
1597
1598 // field values
1599 dump_instance_fields(writer, o);
1600
1601 writer->end_sub_record();
1602 }
1603
1604 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
1605 // its array classes
1606 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
1607 InstanceKlass* ik = InstanceKlass::cast(k);
1608
1609 // We can safepoint and do a heap dump at a point where we have a Klass,
1610 // but no java mirror class has been setup for it. So we need to check
1611 // that the class is at least loaded, to avoid crash from a null mirror.
1612 if (!ik->is_loaded()) {
1613 return;
1614 }
1615
1616 u2 static_fields_count = 0;
1617 u4 static_size = get_static_fields_size(ik, static_fields_count);
1618 u2 instance_fields_count = get_instance_fields_count(ik);
1619 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1620 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size;
1621
1622 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1623
1624 // class ID
1625 writer->write_classID(ik);
1626 writer->write_u4(STACK_TRACE_ID);
1627
1628 // super class ID
1629 InstanceKlass* java_super = ik->java_super();
1630 if (java_super == NULL) {
1631 writer->write_objectID(oop(NULL));
1632 } else {
1633 writer->write_classID(java_super);
1634 }
1635
1636 writer->write_objectID(ik->class_loader());
1637 writer->write_objectID(ik->signers());
1638 writer->write_objectID(ik->protection_domain());
1639
1640 // reserved
1641 writer->write_objectID(oop(NULL));
1642 writer->write_objectID(oop(NULL));
1643
1644 // instance size
1645 writer->write_u4(DumperSupport::instance_size(ik));
1646
1647 // size of constant pool - ignored by HAT 1.1
1648 writer->write_u2(0);
1649
1650 // static fields
1651 writer->write_u2(static_fields_count);
1652 dump_static_fields(writer, ik);
1653
1654 // description of instance fields
1655 writer->write_u2(instance_fields_count);
1656 dump_instance_field_descriptors(writer, ik);
1657
1658 writer->end_sub_record();
1659
1660 // array classes
1661 k = ik->array_klass_or_null();
1662 while (k != NULL) {
1663 assert(k->is_objArray_klass(), "not an ObjArrayKlass");
1664
1665 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1666 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1667 writer->write_classID(k);
1668 writer->write_u4(STACK_TRACE_ID);
1669
1670 // super class of array classes is java.lang.Object
1671 java_super = k->java_super();
1672 assert(java_super != NULL, "checking");
1673 writer->write_classID(java_super);
1674
1675 writer->write_objectID(ik->class_loader());
1676 writer->write_objectID(ik->signers());
1677 writer->write_objectID(ik->protection_domain());
1678
1679 writer->write_objectID(oop(NULL)); // reserved
1680 writer->write_objectID(oop(NULL));
1681 writer->write_u4(0); // instance size
1682 writer->write_u2(0); // constant pool
1683 writer->write_u2(0); // static fields
1684 writer->write_u2(0); // instance fields
1685
1686 writer->end_sub_record();
1687
1688 // get the array class for the next rank
1689 k = k->array_klass_or_null();
1690 }
1691 }
1692
1693 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
1694 // class (and each multi-dimensional array class too)
1695 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) {
1696 // array classes
1697 while (k != NULL) {
1698 Klass* klass = k;
1699
1700 u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1701 writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1702 writer->write_classID(klass);
1703 writer->write_u4(STACK_TRACE_ID);
1704
1705 // super class of array classes is java.lang.Object
1706 InstanceKlass* java_super = klass->java_super();
1707 assert(java_super != NULL, "checking");
1708 writer->write_classID(java_super);
1709
1710 writer->write_objectID(oop(NULL)); // loader
1711 writer->write_objectID(oop(NULL)); // signers
1712 writer->write_objectID(oop(NULL)); // protection domain
1713
1714 writer->write_objectID(oop(NULL)); // reserved
1715 writer->write_objectID(oop(NULL));
1716 writer->write_u4(0); // instance size
1717 writer->write_u2(0); // constant pool
1718 writer->write_u2(0); // static fields
1719 writer->write_u2(0); // instance fields
1720
1721 writer->end_sub_record();
1722
1723 // get the array class for the next rank
1724 k = klass->array_klass_or_null();
1725 }
1726 }
1727
1728 // Hprof uses an u4 as record length field,
1729 // which means we need to truncate arrays that are too long.
1730 int DumperSupport::calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size) {
1731 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1732 assert(type >= T_BOOLEAN && type <= T_OBJECT, "invalid array element type");
1733
1734 int length = array->length();
1735
1736 int type_size;
1737 if (type == T_OBJECT) {
1738 type_size = sizeof(address);
1739 } else {
1740 type_size = type2aelembytes(type);
1741 }
1742
1743 size_t length_in_bytes = (size_t)length * type_size;
1744 uint max_bytes = max_juint - header_size;
1745
1746 if (length_in_bytes > max_bytes) {
1747 length = max_bytes / type_size;
1748 length_in_bytes = (size_t)length * type_size;
1749
1750 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1751 type2name_tab[type], array->length(), length);
1752 }
1753 return length;
1754 }
1755
1756 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1757 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
1758 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1759 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1760 int length = calculate_array_max_length(writer, array, header_size);
1761 u4 size = header_size + length * sizeof(address);
1762
1763 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1764 writer->write_objectID(array);
1765 writer->write_u4(STACK_TRACE_ID);
1766 writer->write_u4(length);
1767
1768 // array class ID
1769 writer->write_classID(array->klass());
1770
1771 // [id]* elements
1772 for (int index = 0; index < length; index++) {
1773 oop o = array->obj_at(index);
1774 if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
1775 ResourceMark rm;
1776 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1777 p2i(o), o->klass()->external_name(),
1778 p2i(array), array->klass()->external_name());
1779 }
1780 o = mask_dormant_archived_object(o);
1781 writer->write_objectID(o);
1782 }
1783
1784 writer->end_sub_record();
1785 }
1786
1787 #define WRITE_ARRAY(Array, Type, Size, Length) \
1788 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1789
1790 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1791 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
1792 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1793
1794 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1795 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1796
1797 int length = calculate_array_max_length(writer, array, header_size);
1798 int type_size = type2aelembytes(type);
1799 u4 length_in_bytes = (u4)length * type_size;
1800 u4 size = header_size + length_in_bytes;
1801
1802 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1803 writer->write_objectID(array);
1804 writer->write_u4(STACK_TRACE_ID);
1805 writer->write_u4(length);
1806 writer->write_u1(type2tag(type));
1807
1808 // nothing to copy
1809 if (length == 0) {
1810 writer->end_sub_record();
1811 return;
1812 }
1813
1814 // If the byte ordering is big endian then we can copy most types directly
1815
1816 switch (type) {
1817 case T_INT : {
1818 if (Endian::is_Java_byte_ordering_different()) {
1819 WRITE_ARRAY(array, int, u4, length);
1820 } else {
1821 writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
1822 }
1823 break;
1824 }
1825 case T_BYTE : {
1826 writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
1827 break;
1828 }
1829 case T_CHAR : {
1830 if (Endian::is_Java_byte_ordering_different()) {
1831 WRITE_ARRAY(array, char, u2, length);
1832 } else {
1833 writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
1834 }
1835 break;
1836 }
1837 case T_SHORT : {
1838 if (Endian::is_Java_byte_ordering_different()) {
1839 WRITE_ARRAY(array, short, u2, length);
1840 } else {
1841 writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
1842 }
1843 break;
1844 }
1845 case T_BOOLEAN : {
1846 if (Endian::is_Java_byte_ordering_different()) {
1847 WRITE_ARRAY(array, bool, u1, length);
1848 } else {
1849 writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
1850 }
1851 break;
1852 }
1853 case T_LONG : {
1854 if (Endian::is_Java_byte_ordering_different()) {
1855 WRITE_ARRAY(array, long, u8, length);
1856 } else {
1857 writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
1858 }
1859 break;
1860 }
1861
1862 // handle float/doubles in a special value to ensure than NaNs are
1863 // written correctly. TO DO: Check if we can avoid this on processors that
1864 // use IEEE 754.
1865
1866 case T_FLOAT : {
1867 for (int i = 0; i < length; i++) {
1868 dump_float(writer, array->float_at(i));
1869 }
1870 break;
1871 }
1872 case T_DOUBLE : {
1873 for (int i = 0; i < length; i++) {
1874 dump_double(writer, array->double_at(i));
1875 }
1876 break;
1877 }
1878 default : ShouldNotReachHere();
1879 }
1880
1881 writer->end_sub_record();
1882 }
1883
1884 // create a HPROF_FRAME record of the given Method* and bci
1885 void DumperSupport::dump_stack_frame(DumpWriter* writer,
1886 int frame_serial_num,
1887 int class_serial_num,
1888 Method* m,
1889 int bci) {
1890 int line_number;
1891 if (m->is_native()) {
1892 line_number = -3; // native frame
1893 } else {
1894 line_number = m->line_number_from_bci(bci);
1895 }
1896
1897 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1898 writer->write_id(frame_serial_num); // frame serial number
1899 writer->write_symbolID(m->name()); // method's name
1900 writer->write_symbolID(m->signature()); // method's signature
1901
1902 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1903 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1904 writer->write_u4(class_serial_num); // class serial number
1905 writer->write_u4((u4) line_number); // line number
1906 }
1907
1908
1909 // Support class used to generate HPROF_UTF8 records from the entries in the
1910 // SymbolTable.
1911
1912 class SymbolTableDumper : public SymbolClosure {
1913 private:
1914 DumpWriter* _writer;
1915 DumpWriter* writer() const { return _writer; }
1916 public:
1917 SymbolTableDumper(DumpWriter* writer) { _writer = writer; }
1918 void do_symbol(Symbol** p);
1919 };
1920
1921 void SymbolTableDumper::do_symbol(Symbol** p) {
1922 ResourceMark rm;
1923 Symbol* sym = load_symbol(p);
1924 int len = sym->utf8_length();
1925 if (len > 0) {
1926 char* s = sym->as_utf8();
1927 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1928 writer()->write_symbolID(sym);
1929 writer()->write_raw(s, len);
1930 }
1931 }
1932
1933 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1934
1935 class JNILocalsDumper : public OopClosure {
1936 private:
1937 DumpWriter* _writer;
1938 u4 _thread_serial_num;
1939 int _frame_num;
1940 DumpWriter* writer() const { return _writer; }
1941 public:
1942 JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
1943 _writer = writer;
1944 _thread_serial_num = thread_serial_num;
1945 _frame_num = -1; // default - empty stack
1946 }
1947 void set_frame_number(int n) { _frame_num = n; }
1948 void do_oop(oop* obj_p);
1949 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1950 };
1951
1952
1953 void JNILocalsDumper::do_oop(oop* obj_p) {
1954 // ignore null handles
1955 oop o = *obj_p;
1956 if (o != NULL) {
1957 u4 size = 1 + sizeof(address) + 4 + 4;
1958 writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
1959 writer()->write_objectID(o);
1960 writer()->write_u4(_thread_serial_num);
1961 writer()->write_u4((u4)_frame_num);
1962 writer()->end_sub_record();
1963 }
1964 }
1965
1966
1967 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
1968
1969 class JNIGlobalsDumper : public OopClosure {
1970 private:
1971 DumpWriter* _writer;
1972 DumpWriter* writer() const { return _writer; }
1973
1974 public:
1975 JNIGlobalsDumper(DumpWriter* writer) {
1976 _writer = writer;
1977 }
1978 void do_oop(oop* obj_p);
1979 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1980 };
1981
1982 void JNIGlobalsDumper::do_oop(oop* obj_p) {
1983 oop o = *obj_p;
1984
1985 // ignore these
1986 if (o == NULL) return;
1987
1988 // we ignore global ref to symbols and other internal objects
1989 if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
1990 u4 size = 1 + 2 * sizeof(address);
1991 writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
1992 writer()->write_objectID(o);
1993 writer()->write_objectID((oopDesc*)obj_p); // global ref ID
1994 writer()->end_sub_record();
1995 }
1996 };
1997
1998
1999 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
2000
2001 class MonitorUsedDumper : public OopClosure {
2002 private:
2003 DumpWriter* _writer;
2004 DumpWriter* writer() const { return _writer; }
2005 public:
2006 MonitorUsedDumper(DumpWriter* writer) {
2007 _writer = writer;
2008 }
2009 void do_oop(oop* obj_p) {
2010 u4 size = 1 + sizeof(address);
2011 writer()->start_sub_record(HPROF_GC_ROOT_MONITOR_USED, size);
2012 writer()->write_objectID(*obj_p);
2013 writer()->end_sub_record();
2014 }
2015 void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
2016 };
2017
2018
2019 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
2020
2021 class StickyClassDumper : public KlassClosure {
2022 private:
2023 DumpWriter* _writer;
2024 DumpWriter* writer() const { return _writer; }
2025 public:
2026 StickyClassDumper(DumpWriter* writer) {
2027 _writer = writer;
2028 }
2029 void do_klass(Klass* k) {
2030 if (k->is_instance_klass()) {
2031 InstanceKlass* ik = InstanceKlass::cast(k);
2032 u4 size = 1 + sizeof(address);
2033 writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
2034 writer()->write_classID(ik);
2035 writer()->end_sub_record();
2036 }
2037 }
2038 };
2039
2040
2041 class VM_HeapDumper;
2042
2043 // Support class using when iterating over the heap.
2044
2045 class HeapObjectDumper : public ObjectClosure {
2046 private:
2047 VM_HeapDumper* _dumper;
2048 DumpWriter* _writer;
2049
2050 VM_HeapDumper* dumper() { return _dumper; }
2051 DumpWriter* writer() { return _writer; }
2052
2053 public:
2054 HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
2055 _dumper = dumper;
2056 _writer = writer;
2057 }
2058
2059 // called for each object in the heap
2060 void do_object(oop o);
2061 };
2062
2063 void HeapObjectDumper::do_object(oop o) {
2064 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
2065 if (o->klass() == SystemDictionary::Class_klass()) {
2066 if (!java_lang_Class::is_primitive(o)) {
2067 return;
2068 }
2069 }
2070
2071 if (DumperSupport::mask_dormant_archived_object(o) == NULL) {
2072 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)", p2i(o), o->klass()->external_name());
2073 return;
2074 }
2075
2076 if (o->is_instance()) {
2077 // create a HPROF_GC_INSTANCE record for each object
2078 DumperSupport::dump_instance(writer(), o);
2079 } else if (o->is_objArray()) {
2080 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
2081 DumperSupport::dump_object_array(writer(), objArrayOop(o));
2082 } else if (o->is_typeArray()) {
2083 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
2084 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
2085 }
2086 }
2087
2088 // The VM operation that performs the heap dump
2089 class VM_HeapDumper : public VM_GC_Operation, public AbstractGangTask {
2090 private:
2091 static VM_HeapDumper* _global_dumper;
2092 static DumpWriter* _global_writer;
2093 DumpWriter* _local_writer;
2094 JavaThread* _oome_thread;
2095 Method* _oome_constructor;
2096 bool _gc_before_heap_dump;
2097 GrowableArray<Klass*>* _klass_map;
2098 ThreadStackTrace** _stack_traces;
2099 int _num_threads;
2100
2101 // accessors and setters
2102 static VM_HeapDumper* dumper() { assert(_global_dumper != NULL, "Error"); return _global_dumper; }
2103 static DumpWriter* writer() { assert(_global_writer != NULL, "Error"); return _global_writer; }
2104 void set_global_dumper() {
2105 assert(_global_dumper == NULL, "Error");
2106 _global_dumper = this;
2107 }
2108 void set_global_writer() {
2109 assert(_global_writer == NULL, "Error");
2110 _global_writer = _local_writer;
2111 }
2112 void clear_global_dumper() { _global_dumper = NULL; }
2113 void clear_global_writer() { _global_writer = NULL; }
2114
2115 bool skip_operation() const;
2116
2117 // writes a HPROF_LOAD_CLASS record
2118 class ClassesDo;
2119 static void do_load_class(Klass* k);
2120
2121 // writes a HPROF_GC_CLASS_DUMP record for the given class
2122 // (and each array class too)
2123 static void do_class_dump(Klass* k);
2124
2125 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
2126 // array (and each multi-dimensional array too)
2127 static void do_basic_type_array_class_dump(Klass* k);
2128
2129 // HPROF_GC_ROOT_THREAD_OBJ records
2130 int do_thread(JavaThread* thread, u4 thread_serial_num);
2131 void do_threads();
2132
2133 void add_class_serial_number(Klass* k, int serial_num) {
2134 _klass_map->at_put_grow(serial_num, k);
2135 }
2136
2137 // HPROF_TRACE and HPROF_FRAME records
2138 void dump_stack_traces();
2139
2140 public:
2141 VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
2142 VM_GC_Operation(0 /* total collections, dummy, ignored */,
2143 GCCause::_heap_dump /* GC Cause */,
2144 0 /* total full collections, dummy, ignored */,
2145 gc_before_heap_dump),
2146 AbstractGangTask("dump heap") {
2147 _local_writer = writer;
2148 _gc_before_heap_dump = gc_before_heap_dump;
2149 _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
2150 _stack_traces = NULL;
2151 _num_threads = 0;
2152 if (oome) {
2153 assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
2154 // get OutOfMemoryError zero-parameter constructor
2155 InstanceKlass* oome_ik = SystemDictionary::OutOfMemoryError_klass();
2156 _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
2157 vmSymbols::void_method_signature());
2158 // get thread throwing OOME when generating the heap dump at OOME
2159 _oome_thread = JavaThread::current();
2160 } else {
2161 _oome_thread = NULL;
2162 _oome_constructor = NULL;
2163 }
2164 }
2165 ~VM_HeapDumper() {
2166 if (_stack_traces != NULL) {
2167 for (int i=0; i < _num_threads; i++) {
2168 delete _stack_traces[i];
2169 }
2170 FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces);
2171 }
2172 delete _klass_map;
2173 }
2174
2175 VMOp_Type type() const { return VMOp_HeapDumper; }
2176 void doit();
2177 void work(uint worker_id);
2178 };
2179
2180
2181 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
2182 DumpWriter* VM_HeapDumper::_global_writer = NULL;
2183
2184 bool VM_HeapDumper::skip_operation() const {
2185 return false;
2186 }
2187
2188 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2189 void DumperSupport::end_of_dump(DumpWriter* writer) {
2190 writer->finish_dump_segment();
2191
2192 writer->write_u1(HPROF_HEAP_DUMP_END);
2193 writer->write_u4(0);
2194 writer->write_u4(0);
2195 }
2196
2197 // writes a HPROF_LOAD_CLASS record for the class (and each of its
2198 // array classes)
2199 void VM_HeapDumper::do_load_class(Klass* k) {
2200 static u4 class_serial_num = 0;
2201
2202 // len of HPROF_LOAD_CLASS record
2203 u4 remaining = 2*oopSize + 2*sizeof(u4);
2204
2205 // write a HPROF_LOAD_CLASS for the class and each array class
2206 do {
2207 DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
2208
2209 // class serial number is just a number
2210 writer()->write_u4(++class_serial_num);
2211
2212 // class ID
2213 Klass* klass = k;
2214 writer()->write_classID(klass);
2215
2216 // add the Klass* and class serial number pair
2217 dumper()->add_class_serial_number(klass, class_serial_num);
2218
2219 writer()->write_u4(STACK_TRACE_ID);
2220
2221 // class name ID
2222 Symbol* name = klass->name();
2223 writer()->write_symbolID(name);
2224
2225 // write a LOAD_CLASS record for the array type (if it exists)
2226 k = klass->array_klass_or_null();
2227 } while (k != NULL);
2228 }
2229
2230 // writes a HPROF_GC_CLASS_DUMP record for the given class
2231 void VM_HeapDumper::do_class_dump(Klass* k) {
2232 if (k->is_instance_klass()) {
2233 DumperSupport::dump_class_and_array_classes(writer(), k);
2234 }
2235 }
2236
2237 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
2238 // array (and each multi-dimensional array too)
2239 void VM_HeapDumper::do_basic_type_array_class_dump(Klass* k) {
2240 DumperSupport::dump_basic_type_array_class(writer(), k);
2241 }
2242
2243 // Walk the stack of the given thread.
2244 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
2245 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
2246 //
2247 // It returns the number of Java frames in this thread stack
2248 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
2249 JNILocalsDumper blk(writer(), thread_serial_num);
2250
2251 oop threadObj = java_thread->threadObj();
2252 assert(threadObj != NULL, "sanity check");
2253
2254 int stack_depth = 0;
2255 if (java_thread->has_last_Java_frame()) {
2256
2257 // vframes are resource allocated
2258 Thread* current_thread = Thread::current();
2259 ResourceMark rm(current_thread);
2260 HandleMark hm(current_thread);
2261
2262 RegisterMap reg_map(java_thread);
2263 frame f = java_thread->last_frame();
2264 vframe* vf = vframe::new_vframe(&f, ®_map, java_thread);
2265 frame* last_entry_frame = NULL;
2266 int extra_frames = 0;
2267
2268 if (java_thread == _oome_thread && _oome_constructor != NULL) {
2269 extra_frames++;
2270 }
2271 while (vf != NULL) {
2272 blk.set_frame_number(stack_depth);
2273 if (vf->is_java_frame()) {
2274
2275 // java frame (interpreted, compiled, ...)
2276 javaVFrame *jvf = javaVFrame::cast(vf);
2277 if (!(jvf->method()->is_native())) {
2278 StackValueCollection* locals = jvf->locals();
2279 for (int slot=0; slot<locals->size(); slot++) {
2280 if (locals->at(slot)->type() == T_OBJECT) {
2281 oop o = locals->obj_at(slot)();
2282
2283 if (o != NULL) {
2284 u4 size = 1 + sizeof(address) + 4 + 4;
2285 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
2286 writer()->write_objectID(o);
2287 writer()->write_u4(thread_serial_num);
2288 writer()->write_u4((u4) (stack_depth + extra_frames));
2289 writer()->end_sub_record();
2290 }
2291 }
2292 }
2293 StackValueCollection *exprs = jvf->expressions();
2294 for(int index = 0; index < exprs->size(); index++) {
2295 if (exprs->at(index)->type() == T_OBJECT) {
2296 oop o = exprs->obj_at(index)();
2297 if (o != NULL) {
2298 u4 size = 1 + sizeof(address) + 4 + 4;
2299 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
2300 writer()->write_objectID(o);
2301 writer()->write_u4(thread_serial_num);
2302 writer()->write_u4((u4) (stack_depth + extra_frames));
2303 writer()->end_sub_record();
2304 }
2305 }
2306 }
2307 } else {
2308 // native frame
2309 if (stack_depth == 0) {
2310 // JNI locals for the top frame.
2311 java_thread->active_handles()->oops_do(&blk);
2312 } else {
2313 if (last_entry_frame != NULL) {
2314 // JNI locals for the entry frame
2315 assert(last_entry_frame->is_entry_frame(), "checking");
2316 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
2317 }
2318 }
2319 }
2320 // increment only for Java frames
2321 stack_depth++;
2322 last_entry_frame = NULL;
2323
2324 } else {
2325 // externalVFrame - if it's an entry frame then report any JNI locals
2326 // as roots when we find the corresponding native javaVFrame
2327 frame* fr = vf->frame_pointer();
2328 assert(fr != NULL, "sanity check");
2329 if (fr->is_entry_frame()) {
2330 last_entry_frame = fr;
2331 }
2332 }
2333 vf = vf->sender();
2334 }
2335 } else {
2336 // no last java frame but there may be JNI locals
2337 java_thread->active_handles()->oops_do(&blk);
2338 }
2339 return stack_depth;
2340 }
2341
2342
2343 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
2344 // the stack so that locals and JNI locals are dumped.
2345 void VM_HeapDumper::do_threads() {
2346 for (int i=0; i < _num_threads; i++) {
2347 JavaThread* thread = _stack_traces[i]->thread();
2348 oop threadObj = thread->threadObj();
2349 u4 thread_serial_num = i+1;
2350 u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
2351 u4 size = 1 + sizeof(address) + 4 + 4;
2352 writer()->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
2353 writer()->write_objectID(threadObj);
2354 writer()->write_u4(thread_serial_num); // thread number
2355 writer()->write_u4(stack_serial_num); // stack trace serial number
2356 writer()->end_sub_record();
2357 int num_frames = do_thread(thread, thread_serial_num);
2358 assert(num_frames == _stack_traces[i]->get_stack_depth(),
2359 "total number of Java frames not matched");
2360 }
2361 }
2362
2363
2364 // The VM operation that dumps the heap. The dump consists of the following
2365 // records:
2366 //
2367 // HPROF_HEADER
2368 // [HPROF_UTF8]*
2369 // [HPROF_LOAD_CLASS]*
2370 // [[HPROF_FRAME]*|HPROF_TRACE]*
2371 // [HPROF_GC_CLASS_DUMP]*
2372 // [HPROF_HEAP_DUMP_SEGMENT]*
2373 // HPROF_HEAP_DUMP_END
2374 //
2375 // The HPROF_TRACE records represent the stack traces where the heap dump
2376 // is generated and a "dummy trace" record which does not include
2377 // any frames. The dummy trace record is used to be referenced as the
2378 // unknown object alloc site.
2379 //
2380 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
2381 // To allow the heap dump be generated in a single pass we remember the position
2382 // of the dump length and fix it up after all sub-records have been written.
2383 // To generate the sub-records we iterate over the heap, writing
2384 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
2385 // records as we go. Once that is done we write records for some of the GC
2386 // roots.
2387
2388 void VM_HeapDumper::doit() {
2389
2390 HandleMark hm;
2391 CollectedHeap* ch = Universe::heap();
2392
2393 ch->ensure_parsability(false); // must happen, even if collection does
2394 // not happen (e.g. due to GCLocker)
2395
2396 if (_gc_before_heap_dump) {
2397 if (GCLocker::is_active()) {
2398 warning("GC locker is held; pre-heapdump GC was skipped");
2399 } else {
2400 ch->collect_as_vm_thread(GCCause::_heap_dump);
2401 }
2402 }
2403
2404 // At this point we should be the only dumper active, so
2405 // the following should be safe.
2406 set_global_dumper();
2407 set_global_writer();
2408
2409 WorkGang* gang = UseShenandoahGC ? NULL : ch->get_safepoint_workers();
2410
2411 if (gang == NULL) {
2412 work(0);
2413 } else {
2414 gang->run_task(this);
2415 }
2416
2417 // Now we clear the global variables, so that a future dumper might run.
2418 clear_global_dumper();
2419 clear_global_writer();
2420 }
2421
2422 void VM_HeapDumper::work(uint worker_id) {
2423 if (worker_id != 0) {
2424 writer()->writer_loop();
2425 return;
2426 }
2427
2428 // Write the file header - we always use 1.0.
2429 const char* header = "JAVA PROFILE 1.0.2";
2430
2431 // header is few bytes long - no chance to overflow int
2432 writer()->write_raw((void*)header, (int)strlen(header));
2433 writer()->write_u1(0); // terminator
2434 writer()->write_u4(oopSize);
2435 // timestamp is current time in ms
2436 writer()->write_u8(os::javaTimeMillis());
2437
2438 // HPROF_UTF8 records
2439 SymbolTableDumper sym_dumper(writer());
2440 SymbolTable::symbols_do(&sym_dumper);
2441
2442 // write HPROF_LOAD_CLASS records
2443 {
2444 LockedClassesDo locked_load_classes(&do_load_class);
2445 ClassLoaderDataGraph::classes_do(&locked_load_classes);
2446 }
2447 Universe::basic_type_classes_do(&do_load_class);
2448
2449 // write HPROF_FRAME and HPROF_TRACE records
2450 // this must be called after _klass_map is built when iterating the classes above.
2451 dump_stack_traces();
2452
2453 // Writes HPROF_GC_CLASS_DUMP records
2454 {
2455 LockedClassesDo locked_dump_class(&do_class_dump);
2456 ClassLoaderDataGraph::classes_do(&locked_dump_class);
2457 }
2458 Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
2459
2460 // writes HPROF_GC_INSTANCE_DUMP records.
2461 // After each sub-record is written check_segment_length will be invoked
2462 // to check if the current segment exceeds a threshold. If so, a new
2463 // segment is started.
2464 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
2465 // of the heap dump.
2466 HeapObjectDumper obj_dumper(this, writer());
2467 Universe::heap()->object_iterate(&obj_dumper);
2468
2469 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
2470 do_threads();
2471
2472 // HPROF_GC_ROOT_MONITOR_USED
2473 MonitorUsedDumper mon_dumper(writer());
2474 ObjectSynchronizer::oops_do(&mon_dumper);
2475
2476 // HPROF_GC_ROOT_JNI_GLOBAL
2477 JNIGlobalsDumper jni_dumper(writer());
2478 JNIHandles::oops_do(&jni_dumper);
2479 Universe::oops_do(&jni_dumper); // technically not jni roots, but global roots
2480 // for things like preallocated throwable backtraces
2481
2482 // HPROF_GC_ROOT_STICKY_CLASS
2483 // These should be classes in the NULL class loader data, and not all classes
2484 // if !ClassUnloading
2485 StickyClassDumper class_dumper(writer());
2486 ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper);
2487
2488 // Writes the HPROF_HEAP_DUMP_END record.
2489 DumperSupport::end_of_dump(writer());
2490
2491 // We are done with writing. Release the worker threads.
2492 writer()->deactivate();
2493 }
2494
2495 void VM_HeapDumper::dump_stack_traces() {
2496 // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
2497 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
2498 writer()->write_u4((u4) STACK_TRACE_ID);
2499 writer()->write_u4(0); // thread number
2500 writer()->write_u4(0); // frame count
2501
2502 _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal);
2503 int frame_serial_num = 0;
2504 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
2505 oop threadObj = thread->threadObj();
2506 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
2507 // dump thread stack trace
2508 ResourceMark rm;
2509 ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
2510 stack_trace->dump_stack_at_safepoint(-1);
2511 _stack_traces[_num_threads++] = stack_trace;
2512
2513 // write HPROF_FRAME records for this thread's stack trace
2514 int depth = stack_trace->get_stack_depth();
2515 int thread_frame_start = frame_serial_num;
2516 int extra_frames = 0;
2517 // write fake frame that makes it look like the thread, which caused OOME,
2518 // is in the OutOfMemoryError zero-parameter constructor
2519 if (thread == _oome_thread && _oome_constructor != NULL) {
2520 int oome_serial_num = _klass_map->find(_oome_constructor->method_holder());
2521 // the class serial number starts from 1
2522 assert(oome_serial_num > 0, "OutOfMemoryError class not found");
2523 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
2524 _oome_constructor, 0);
2525 extra_frames++;
2526 }
2527 for (int j=0; j < depth; j++) {
2528 StackFrameInfo* frame = stack_trace->stack_frame_at(j);
2529 Method* m = frame->method();
2530 int class_serial_num = _klass_map->find(m->method_holder());
2531 // the class serial number starts from 1
2532 assert(class_serial_num > 0, "class not found");
2533 DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
2534 }
2535 depth += extra_frames;
2536
2537 // write HPROF_TRACE record for one thread
2538 DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
2539 int stack_serial_num = _num_threads + STACK_TRACE_ID;
2540 writer()->write_u4(stack_serial_num); // stack trace serial number
2541 writer()->write_u4((u4) _num_threads); // thread serial number
2542 writer()->write_u4(depth); // frame count
2543 for (int j=1; j <= depth; j++) {
2544 writer()->write_id(thread_frame_start + j);
2545 }
2546 }
2547 }
2548 }
2549
2550 // dump the heap to given path.
2551 int HeapDumper::dump(const char* path, outputStream* out, int compression) {
2552 assert(path != NULL && strlen(path) > 0, "path missing");
2553
2554 // print message in interactive case
2555 if (out != NULL) {
2556 out->print_cr("Dumping heap to %s ...", path);
2557 timer()->start();
2558 }
2559
2560 // create JFR event
2561 EventHeapDump event;
2562
2563 AbstractCompressor* compressor = NULL;
2564
2565 if (compression > 0) {
2566 compressor = new (std::nothrow) GZipComressor(compression);
2567
2568 if (compressor == NULL) {
2569 set_error("Could not allocate gzip compressor");
2570 return -1;
2571 }
2572 }
2573
2574 DumpWriter writer(new (std::nothrow) FileWriter(path), compressor);
2575
2576 if (writer.error() != NULL) {
2577 set_error(writer.error());
2578 if (out != NULL) {
2579 out->print_cr("Unable to create %s: %s", path,
2580 (error() != NULL) ? error() : "reason unknown");
2581 }
2582 return -1;
2583 }
2584
2585 // generate the dump
2586 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
2587 if (Thread::current()->is_VM_thread()) {
2588 assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
2589 dumper.doit();
2590 } else {
2591 VMThread::execute(&dumper);
2592 }
2593
2594 // record any error that the writer may have encountered
2595 set_error(writer.error());
2596
2597 // emit JFR event
2598 if (error() == NULL) {
2599 event.set_destination(path);
2600 event.set_gcBeforeDump(_gc_before_heap_dump);
2601 event.set_size(writer.bytes_written());
2602 event.set_onOutOfMemoryError(_oome);
2603 event.commit();
2604 }
2605
2606 // print message in interactive case
2607 if (out != NULL) {
2608 timer()->stop();
2609 if (error() == NULL) {
2610 out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
2611 writer.bytes_written(), timer()->seconds());
2612 } else {
2613 out->print_cr("Dump file is incomplete: %s", writer.error());
2614 }
2615 }
2616
2617 return (writer.error() == NULL) ? 0 : -1;
2618 }
2619
2620 // stop timer (if still active), and free any error string we might be holding
2621 HeapDumper::~HeapDumper() {
2622 if (timer()->is_active()) {
2623 timer()->stop();
2624 }
2625 set_error(NULL);
2626 }
2627
2628
2629 // returns the error string (resource allocated), or NULL
2630 char* HeapDumper::error_as_C_string() const {
2631 if (error() != NULL) {
2632 char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
2633 strcpy(str, error());
2634 return str;
2635 } else {
2636 return NULL;
2637 }
2638 }
2639
2640 // set the error string
2641 void HeapDumper::set_error(char const* error) {
2642 if (_error != NULL) {
2643 os::free(_error);
2644 }
2645 if (error == NULL) {
2646 _error = NULL;
2647 } else {
2648 _error = os::strdup(error);
2649 assert(_error != NULL, "allocation failure");
2650 }
2651 }
2652
2653 // Called by out-of-memory error reporting by a single Java thread
2654 // outside of a JVM safepoint
2655 void HeapDumper::dump_heap_from_oome() {
2656 HeapDumper::dump_heap(true);
2657 }
2658
2659 // Called by error reporting by a single Java thread outside of a JVM safepoint,
2660 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
2661 // callers are strictly serialized and guaranteed not to interfere below. For more
2662 // general use, however, this method will need modification to prevent
2663 // inteference when updating the static variables base_path and dump_file_seq below.
2664 void HeapDumper::dump_heap() {
2665 HeapDumper::dump_heap(false);
2666 }
2667
2668 void HeapDumper::dump_heap(bool oome) {
2669 static char base_path[JVM_MAXPATHLEN] = {'\0'};
2670 static uint dump_file_seq = 0;
2671 char* my_path;
2672 const int max_digit_chars = 20;
2673
2674 const char* dump_file_name = "java_pid";
2675 const char* dump_file_ext = ".hprof";
2676
2677 // The dump file defaults to java_pid<pid>.hprof in the current working
2678 // directory. HeapDumpPath=<file> can be used to specify an alternative
2679 // dump file name or a directory where dump file is created.
2680 if (dump_file_seq == 0) { // first time in, we initialize base_path
2681 // Calculate potentially longest base path and check if we have enough
2682 // allocated statically.
2683 const size_t total_length =
2684 (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
2685 strlen(os::file_separator()) + max_digit_chars +
2686 strlen(dump_file_name) + strlen(dump_file_ext) + 1;
2687 if (total_length > sizeof(base_path)) {
2688 warning("Cannot create heap dump file. HeapDumpPath is too long.");
2689 return;
2690 }
2691
2692 bool use_default_filename = true;
2693 if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
2694 // HeapDumpPath=<file> not specified
2695 } else {
2696 strcpy(base_path, HeapDumpPath);
2697 // check if the path is a directory (must exist)
2698 DIR* dir = os::opendir(base_path);
2699 if (dir == NULL) {
2700 use_default_filename = false;
2701 } else {
2702 // HeapDumpPath specified a directory. We append a file separator
2703 // (if needed).
2704 os::closedir(dir);
2705 size_t fs_len = strlen(os::file_separator());
2706 if (strlen(base_path) >= fs_len) {
2707 char* end = base_path;
2708 end += (strlen(base_path) - fs_len);
2709 if (strcmp(end, os::file_separator()) != 0) {
2710 strcat(base_path, os::file_separator());
2711 }
2712 }
2713 }
2714 }
2715 // If HeapDumpPath wasn't a file name then we append the default name
2716 if (use_default_filename) {
2717 const size_t dlen = strlen(base_path); // if heap dump dir specified
2718 jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
2719 dump_file_name, os::current_process_id(), dump_file_ext);
2720 }
2721 const size_t len = strlen(base_path) + 1;
2722 my_path = (char*)os::malloc(len, mtInternal);
2723 if (my_path == NULL) {
2724 warning("Cannot create heap dump file. Out of system memory.");
2725 return;
2726 }
2727 strncpy(my_path, base_path, len);
2728 } else {
2729 // Append a sequence number id for dumps following the first
2730 const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
2731 my_path = (char*)os::malloc(len, mtInternal);
2732 if (my_path == NULL) {
2733 warning("Cannot create heap dump file. Out of system memory.");
2734 return;
2735 }
2736 jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
2737 }
2738 dump_file_seq++; // increment seq number for next time we dump
2739
2740 HeapDumper dumper(false /* no GC before heap dump */,
2741 oome /* pass along out-of-memory-error flag */);
2742 dumper.dump(my_path, tty);
2743 os::free(my_path);
2744 }