rev 58388 : 8237354: Add option to jcmd to write a gzipped heap dump
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   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 "jfr/jfrEvents.hpp"
  36 #include "memory/allocation.inline.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "memory/universe.hpp"
  39 #include "oops/objArrayKlass.hpp"
  40 #include "oops/objArrayOop.inline.hpp"
  41 #include "oops/oop.inline.hpp"
  42 #include "oops/typeArrayOop.inline.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/handles.inline.hpp"
  45 #include "runtime/javaCalls.hpp"
  46 #include "runtime/jniHandles.hpp"
  47 #include "runtime/os.inline.hpp"
  48 #include "runtime/reflectionUtils.hpp"
  49 #include "runtime/thread.inline.hpp"
  50 #include "runtime/threadSMR.hpp"
  51 #include "runtime/vframe.hpp"
  52 #include "runtime/vmThread.hpp"
  53 #include "runtime/vmOperations.hpp"
  54 #include "services/heapDumper.hpp"
  55 #include "services/threadService.hpp"
  56 #include "utilities/macros.hpp"
  57 #include "utilities/ostream.hpp"
  58 
  59 /*
  60  * HPROF binary format - description copied from:
  61  *   src/share/demo/jvmti/hprof/hprof_io.c
  62  *
  63  *
  64  *  header    "JAVA PROFILE 1.0.2" (0-terminated)
  65  *
  66  *  u4        size of identifiers. Identifiers are used to represent
  67  *            UTF8 strings, objects, stack traces, etc. They usually
  68  *            have the same size as host pointers. For example, on
  69  *            Solaris and Win32, the size is 4.
  70  * u4         high word
  71  * u4         low word    number of milliseconds since 0:00 GMT, 1/1/70
  72  * [record]*  a sequence of records.
  73  *
  74  *
  75  * Record format:
  76  *
  77  * u1         a TAG denoting the type of the record
  78  * u4         number of *microseconds* since the time stamp in the
  79  *            header. (wraps around in a little more than an hour)
  80  * u4         number of bytes *remaining* in the record. Note that
  81  *            this number excludes the tag and the length field itself.
  82  * [u1]*      BODY of the record (a sequence of bytes)
  83  *
  84  *
  85  * The following TAGs are supported:
  86  *
  87  * TAG           BODY       notes
  88  *----------------------------------------------------------
  89  * HPROF_UTF8               a UTF8-encoded name
  90  *
  91  *               id         name ID
  92  *               [u1]*      UTF8 characters (no trailing zero)
  93  *
  94  * HPROF_LOAD_CLASS         a newly loaded class
  95  *
  96  *                u4        class serial number (> 0)
  97  *                id        class object ID
  98  *                u4        stack trace serial number
  99  *                id        class name ID
 100  *
 101  * HPROF_UNLOAD_CLASS       an unloading class
 102  *
 103  *                u4        class serial_number
 104  *
 105  * HPROF_FRAME              a Java stack frame
 106  *
 107  *                id        stack frame ID
 108  *                id        method name ID
 109  *                id        method signature ID
 110  *                id        source file name ID
 111  *                u4        class serial number
 112  *                i4        line number. >0: normal
 113  *                                       -1: unknown
 114  *                                       -2: compiled method
 115  *                                       -3: native method
 116  *
 117  * HPROF_TRACE              a Java stack trace
 118  *
 119  *               u4         stack trace serial number
 120  *               u4         thread serial number
 121  *               u4         number of frames
 122  *               [id]*      stack frame IDs
 123  *
 124  *
 125  * HPROF_ALLOC_SITES        a set of heap allocation sites, obtained after GC
 126  *
 127  *               u2         flags 0x0001: incremental vs. complete
 128  *                                0x0002: sorted by allocation vs. live
 129  *                                0x0004: whether to force a GC
 130  *               u4         cutoff ratio
 131  *               u4         total live bytes
 132  *               u4         total live instances
 133  *               u8         total bytes allocated
 134  *               u8         total instances allocated
 135  *               u4         number of sites that follow
 136  *               [u1        is_array: 0:  normal object
 137  *                                    2:  object array
 138  *                                    4:  boolean array
 139  *                                    5:  char array
 140  *                                    6:  float array
 141  *                                    7:  double array
 142  *                                    8:  byte array
 143  *                                    9:  short array
 144  *                                    10: int array
 145  *                                    11: long array
 146  *                u4        class serial number (may be zero during startup)
 147  *                u4        stack trace serial number
 148  *                u4        number of bytes alive
 149  *                u4        number of instances alive
 150  *                u4        number of bytes allocated
 151  *                u4]*      number of instance allocated
 152  *
 153  * HPROF_START_THREAD       a newly started thread.
 154  *
 155  *               u4         thread serial number (> 0)
 156  *               id         thread object ID
 157  *               u4         stack trace serial number
 158  *               id         thread name ID
 159  *               id         thread group name ID
 160  *               id         thread group parent name ID
 161  *
 162  * HPROF_END_THREAD         a terminating thread.
 163  *
 164  *               u4         thread serial number
 165  *
 166  * HPROF_HEAP_SUMMARY       heap summary
 167  *
 168  *               u4         total live bytes
 169  *               u4         total live instances
 170  *               u8         total bytes allocated
 171  *               u8         total instances allocated
 172  *
 173  * HPROF_HEAP_DUMP          denote a heap dump
 174  *
 175  *               [heap dump sub-records]*
 176  *
 177  *                          There are four kinds of heap dump sub-records:
 178  *
 179  *               u1         sub-record type
 180  *
 181  *               HPROF_GC_ROOT_UNKNOWN         unknown root
 182  *
 183  *                          id         object ID
 184  *
 185  *               HPROF_GC_ROOT_THREAD_OBJ      thread object
 186  *
 187  *                          id         thread object ID  (may be 0 for a
 188  *                                     thread newly attached through JNI)
 189  *                          u4         thread sequence number
 190  *                          u4         stack trace sequence number
 191  *
 192  *               HPROF_GC_ROOT_JNI_GLOBAL      JNI global ref root
 193  *
 194  *                          id         object ID
 195  *                          id         JNI global ref ID
 196  *
 197  *               HPROF_GC_ROOT_JNI_LOCAL       JNI local ref
 198  *
 199  *                          id         object ID
 200  *                          u4         thread serial number
 201  *                          u4         frame # in stack trace (-1 for empty)
 202  *
 203  *               HPROF_GC_ROOT_JAVA_FRAME      Java stack frame
 204  *
 205  *                          id         object ID
 206  *                          u4         thread serial number
 207  *                          u4         frame # in stack trace (-1 for empty)
 208  *
 209  *               HPROF_GC_ROOT_NATIVE_STACK    Native stack
 210  *
 211  *                          id         object ID
 212  *                          u4         thread serial number
 213  *
 214  *               HPROF_GC_ROOT_STICKY_CLASS    System class
 215  *
 216  *                          id         object ID
 217  *
 218  *               HPROF_GC_ROOT_THREAD_BLOCK    Reference from thread block
 219  *
 220  *                          id         object ID
 221  *                          u4         thread serial number
 222  *
 223  *               HPROF_GC_ROOT_MONITOR_USED    Busy monitor
 224  *
 225  *                          id         object ID
 226  *
 227  *               HPROF_GC_CLASS_DUMP           dump of a class object
 228  *
 229  *                          id         class object ID
 230  *                          u4         stack trace serial number
 231  *                          id         super class object ID
 232  *                          id         class loader object ID
 233  *                          id         signers object ID
 234  *                          id         protection domain object ID
 235  *                          id         reserved
 236  *                          id         reserved
 237  *
 238  *                          u4         instance size (in bytes)
 239  *
 240  *                          u2         size of constant pool
 241  *                          [u2,       constant pool index,
 242  *                           ty,       type
 243  *                                     2:  object
 244  *                                     4:  boolean
 245  *                                     5:  char
 246  *                                     6:  float
 247  *                                     7:  double
 248  *                                     8:  byte
 249  *                                     9:  short
 250  *                                     10: int
 251  *                                     11: long
 252  *                           vl]*      and value
 253  *
 254  *                          u2         number of static fields
 255  *                          [id,       static field name,
 256  *                           ty,       type,
 257  *                           vl]*      and value
 258  *
 259  *                          u2         number of inst. fields (not inc. super)
 260  *                          [id,       instance field name,
 261  *                           ty]*      type
 262  *
 263  *               HPROF_GC_INSTANCE_DUMP        dump of a normal object
 264  *
 265  *                          id         object ID
 266  *                          u4         stack trace serial number
 267  *                          id         class object ID
 268  *                          u4         number of bytes that follow
 269  *                          [vl]*      instance field values (class, followed
 270  *                                     by super, super's super ...)
 271  *
 272  *               HPROF_GC_OBJ_ARRAY_DUMP       dump of an object array
 273  *
 274  *                          id         array object ID
 275  *                          u4         stack trace serial number
 276  *                          u4         number of elements
 277  *                          id         array class ID
 278  *                          [id]*      elements
 279  *
 280  *               HPROF_GC_PRIM_ARRAY_DUMP      dump of a primitive array
 281  *
 282  *                          id         array object ID
 283  *                          u4         stack trace serial number
 284  *                          u4         number of elements
 285  *                          u1         element type
 286  *                                     4:  boolean array
 287  *                                     5:  char array
 288  *                                     6:  float array
 289  *                                     7:  double array
 290  *                                     8:  byte array
 291  *                                     9:  short array
 292  *                                     10: int array
 293  *                                     11: long array
 294  *                          [u1]*      elements
 295  *
 296  * HPROF_CPU_SAMPLES        a set of sample traces of running threads
 297  *
 298  *                u4        total number of samples
 299  *                u4        # of traces
 300  *               [u4        # of samples
 301  *                u4]*      stack trace serial number
 302  *
 303  * HPROF_CONTROL_SETTINGS   the settings of on/off switches
 304  *
 305  *                u4        0x00000001: alloc traces on/off
 306  *                          0x00000002: cpu sampling on/off
 307  *                u2        stack trace depth
 308  *
 309  *
 310  * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
 311  * be generated as a sequence of heap dump segments. This sequence is
 312  * terminated by an end record. The additional tags allowed by format
 313  * "JAVA PROFILE 1.0.2" are:
 314  *
 315  * HPROF_HEAP_DUMP_SEGMENT  denote a heap dump segment
 316  *
 317  *               [heap dump sub-records]*
 318  *               The same sub-record types allowed by HPROF_HEAP_DUMP
 319  *
 320  * HPROF_HEAP_DUMP_END      denotes the end of a heap dump
 321  *
 322  */
 323 
 324 
 325 // HPROF tags
 326 
 327 typedef enum {
 328   // top-level records
 329   HPROF_UTF8                    = 0x01,
 330   HPROF_LOAD_CLASS              = 0x02,
 331   HPROF_UNLOAD_CLASS            = 0x03,
 332   HPROF_FRAME                   = 0x04,
 333   HPROF_TRACE                   = 0x05,
 334   HPROF_ALLOC_SITES             = 0x06,
 335   HPROF_HEAP_SUMMARY            = 0x07,
 336   HPROF_START_THREAD            = 0x0A,
 337   HPROF_END_THREAD              = 0x0B,
 338   HPROF_HEAP_DUMP               = 0x0C,
 339   HPROF_CPU_SAMPLES             = 0x0D,
 340   HPROF_CONTROL_SETTINGS        = 0x0E,
 341 
 342   // 1.0.2 record types
 343   HPROF_HEAP_DUMP_SEGMENT       = 0x1C,
 344   HPROF_HEAP_DUMP_END           = 0x2C,
 345 
 346   // field types
 347   HPROF_ARRAY_OBJECT            = 0x01,
 348   HPROF_NORMAL_OBJECT           = 0x02,
 349   HPROF_BOOLEAN                 = 0x04,
 350   HPROF_CHAR                    = 0x05,
 351   HPROF_FLOAT                   = 0x06,
 352   HPROF_DOUBLE                  = 0x07,
 353   HPROF_BYTE                    = 0x08,
 354   HPROF_SHORT                   = 0x09,
 355   HPROF_INT                     = 0x0A,
 356   HPROF_LONG                    = 0x0B,
 357 
 358   // data-dump sub-records
 359   HPROF_GC_ROOT_UNKNOWN         = 0xFF,
 360   HPROF_GC_ROOT_JNI_GLOBAL      = 0x01,
 361   HPROF_GC_ROOT_JNI_LOCAL       = 0x02,
 362   HPROF_GC_ROOT_JAVA_FRAME      = 0x03,
 363   HPROF_GC_ROOT_NATIVE_STACK    = 0x04,
 364   HPROF_GC_ROOT_STICKY_CLASS    = 0x05,
 365   HPROF_GC_ROOT_THREAD_BLOCK    = 0x06,
 366   HPROF_GC_ROOT_MONITOR_USED    = 0x07,
 367   HPROF_GC_ROOT_THREAD_OBJ      = 0x08,
 368   HPROF_GC_CLASS_DUMP           = 0x20,
 369   HPROF_GC_INSTANCE_DUMP        = 0x21,
 370   HPROF_GC_OBJ_ARRAY_DUMP       = 0x22,
 371   HPROF_GC_PRIM_ARRAY_DUMP      = 0x23
 372 } hprofTag;
 373 
 374 // Default stack trace ID (used for dummy HPROF_TRACE record)
 375 enum {
 376   STACK_TRACE_ID = 1,
 377   INITIAL_CLASS_COUNT = 200
 378 };
 379 
 380 // Supports I/O operations on a dump file






































































































































































































































































































































































































































































































































































































































 381 
 382 class DumpWriter : public StackObj {
 383  private:
 384   enum {
 385     io_buffer_max_size = 8*M,
 386     io_buffer_min_size = 64*K,
 387     dump_segment_header_size = 9
 388   };
 389 
 390   int _fd;              // file descriptor (-1 if dump file not open)
 391   julong _bytes_written; // number of byte written to dump file
 392 
 393   char* _buffer;    // internal buffer
 394   size_t _size;
 395   size_t _pos;
 396 
 397   bool _in_dump_segment; // Are we currently in a dump segment?
 398   bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
 399   DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
 400   DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
 401 
 402   char* _error;   // error message when I/O fails
 403 
 404   void set_file_descriptor(int fd)              { _fd = fd; }
 405   int file_descriptor() const                   { return _fd; }
 406 
 407   bool is_open() const                          { return file_descriptor() >= 0; }
 408   void flush();
 409 
 410   char* buffer() const                          { return _buffer; }
 411   size_t buffer_size() const                    { return _size; }
 412   size_t position() const                       { return _pos; }
 413   void set_position(size_t pos)                 { _pos = pos; }
 414 
 415   void set_error(const char* error)             { _error = (char*)os::strdup(error); }

 416 
 417   // all I/O go through this function
 418   void write_internal(void* s, size_t len);
 419 
 420  public:
 421   DumpWriter(const char* path);
 422   ~DumpWriter();
 423 
 424   void close();
 425 
 426   // total number of bytes written to the disk
 427   julong bytes_written() const          { return _bytes_written; }
 428 
 429   char* error() const                   { return _error; }
 430 
 431   // writer functions
 432   void write_raw(void* s, size_t len);
 433   void write_u1(u1 x)                   { write_raw((void*)&x, 1); }
 434   void write_u2(u2 x);
 435   void write_u4(u4 x);
 436   void write_u8(u8 x);
 437   void write_objectID(oop o);
 438   void write_symbolID(Symbol* o);
 439   void write_classID(Klass* k);
 440   void write_id(u4 x);
 441 
 442   // Start a new sub-record. Starts a new heap dump segment if needed.
 443   void start_sub_record(u1 tag, u4 len);
 444   // Ends the current sub-record.
 445   void end_sub_record();
 446   // Finishes the current dump segment if not already finished.
 447   void finish_dump_segment();
 448 };
 449 
 450 DumpWriter::DumpWriter(const char* path) : _fd(-1), _bytes_written(0), _pos(0),
 451                                            _in_dump_segment(false), _error(NULL) {
 452   // try to allocate an I/O buffer of io_buffer_size. If there isn't
 453   // sufficient memory then reduce size until we can allocate something.
 454   _size = io_buffer_max_size;
 455   do {
 456     _buffer = (char*)os::malloc(_size, mtInternal);
 457     if (_buffer == NULL) {
 458       _size = _size >> 1;
 459     }
 460   } while (_buffer == NULL && _size >= io_buffer_min_size);
 461 
 462   if (_buffer == NULL) {
 463     set_error("Could not allocate buffer memory for heap dump");
 464   } else {
 465     _fd = os::create_binary_file(path, false);    // don't replace existing file
 466 
 467     // if the open failed we record the error
 468     if (_fd < 0) {
 469       set_error(os::strerror(errno));
 470     }
 471   }


 472 }
 473 
 474 DumpWriter::~DumpWriter() {
 475   close();
 476   os::free(_buffer);
 477   os::free(_error);
 478 }
 479 
 480 // closes dump file (if open)
 481 void DumpWriter::close() {
 482   // flush and close dump file
 483   if (is_open()) {
 484     flush();
 485     os::close(file_descriptor());
 486     set_file_descriptor(-1);
 487   }
 488 }
 489 
 490 // write directly to the file
 491 void DumpWriter::write_internal(void* s, size_t len) {
 492   if (is_open()) {
 493     const char* pos = (char*)s;
 494     ssize_t n = 0;
 495     while (len > 0) {
 496       uint tmp = (uint)MIN2(len, (size_t)INT_MAX);
 497       n = os::write(file_descriptor(), pos, tmp);
 498 
 499       if (n < 0) {
 500         // EINTR cannot happen here, os::write will take care of that
 501         set_error(os::strerror(errno));
 502         os::close(file_descriptor());
 503         set_file_descriptor(-1);
 504         return;
 505       }
 506 
 507       _bytes_written += n;
 508       pos += n;
 509       len -= n;
 510     }
 511   }

 512 }
 513 
 514 // write raw bytes
 515 void DumpWriter::write_raw(void* s, size_t len) {
 516   assert(!_in_dump_segment || (_sub_record_left >= len), "sub-record too large");
 517   debug_only(_sub_record_left -= len);
 518 
 519   // flush buffer to make room
 520   if (len > buffer_size() - position()) {
 521     assert(!_in_dump_segment || _is_huge_sub_record, "Cannot overflow in non-huge sub-record.");
 522     flush();
 523 
 524     // If larger than the buffer, just write it directly.
 525     if (len > buffer_size()) {
 526       write_internal(s, len);
 527 
 528       return;
 529     }




 530   }
 531 
 532   memcpy(buffer() + position(), s, len);
 533   set_position(position() + len);
 534 }
 535 
 536 // flush any buffered bytes to the file
 537 void DumpWriter::flush() {
 538   write_internal(buffer(), position());
 539   set_position(0);







 540 }
 541 
 542 void DumpWriter::write_u2(u2 x) {
 543   u2 v;
 544   Bytes::put_Java_u2((address)&v, x);
 545   write_raw((void*)&v, 2);
 546 }
 547 
 548 void DumpWriter::write_u4(u4 x) {
 549   u4 v;
 550   Bytes::put_Java_u4((address)&v, x);
 551   write_raw((void*)&v, 4);
 552 }
 553 
 554 void DumpWriter::write_u8(u8 x) {
 555   u8 v;
 556   Bytes::put_Java_u8((address)&v, x);
 557   write_raw((void*)&v, 8);
 558 }
 559 
 560 void DumpWriter::write_objectID(oop o) {
 561   address a = cast_from_oop<address>(o);
 562 #ifdef _LP64
 563   write_u8((u8)a);
 564 #else
 565   write_u4((u4)a);
 566 #endif
 567 }
 568 
 569 void DumpWriter::write_symbolID(Symbol* s) {
 570   address a = (address)((uintptr_t)s);
 571 #ifdef _LP64
 572   write_u8((u8)a);
 573 #else
 574   write_u4((u4)a);
 575 #endif
 576 }
 577 
 578 void DumpWriter::write_id(u4 x) {
 579 #ifdef _LP64
 580   write_u8((u8) x);
 581 #else
 582   write_u4(x);
 583 #endif
 584 }
 585 
 586 // We use java mirror as the class ID
 587 void DumpWriter::write_classID(Klass* k) {
 588   write_objectID(k->java_mirror());
 589 }
 590 
 591 void DumpWriter::finish_dump_segment() {
 592   if (_in_dump_segment) {
 593     assert(_sub_record_left == 0, "Last sub-record not written completely");
 594     assert(_sub_record_ended, "sub-record must have ended");
 595 
 596     // Fix up the dump segment length if we haven't written a huge sub-record last
 597     // (in which case the segment length was already set to the correct value initially).
 598     if (!_is_huge_sub_record) {
 599       assert(position() > dump_segment_header_size, "Dump segment should have some content");
 600       Bytes::put_Java_u4((address) (buffer() + 5), (u4) (position() - dump_segment_header_size));
 601     }
 602 
 603     flush();
 604     _in_dump_segment = false;
 605   }
 606 }
 607 
 608 void DumpWriter::start_sub_record(u1 tag, u4 len) {
 609   if (!_in_dump_segment) {
 610     if (position() > 0) {
 611       flush();
 612       assert(position() == 0, "Must be at the start");
 613     }
 614 


 615     write_u1(HPROF_HEAP_DUMP_SEGMENT);
 616     write_u4(0); // timestamp
 617     // Will be fixed up later if we add more sub-records.  If this is a huge sub-record,
 618     // this is already the correct length, since we don't add more sub-records.
 619     write_u4(len);
 620     _in_dump_segment = true;
 621     _is_huge_sub_record = len > buffer_size() - dump_segment_header_size;
 622   } else if (_is_huge_sub_record || (len > buffer_size() - position())) {
 623     // This object will not fit in completely or the last sub-record was huge.
 624     // Finish the current segement and try again.
 625     finish_dump_segment();
 626     start_sub_record(tag, len);
 627 
 628     return;
 629   }
 630 
 631   debug_only(_sub_record_left = len);
 632   debug_only(_sub_record_ended = false);
 633 
 634   write_u1(tag);
 635 }
 636 
 637 void DumpWriter::end_sub_record() {
 638   assert(_in_dump_segment, "must be in dump segment");
 639   assert(_sub_record_left == 0, "sub-record not written completely");
 640   assert(!_sub_record_ended, "Must not have ended yet");
 641   debug_only(_sub_record_ended = true);
 642 }
 643 
 644 // Support class with a collection of functions used when dumping the heap
 645 
 646 class DumperSupport : AllStatic {
 647  public:
 648 
 649   // write a header of the given type
 650   static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
 651 
 652   // returns hprof tag for the given type signature
 653   static hprofTag sig2tag(Symbol* sig);
 654   // returns hprof tag for the given basic type
 655   static hprofTag type2tag(BasicType type);
 656   // Returns the size of the data to write.
 657   static u4 sig2size(Symbol* sig);
 658 
 659   // returns the size of the instance of the given class
 660   static u4 instance_size(Klass* k);
 661 
 662   // dump a jfloat
 663   static void dump_float(DumpWriter* writer, jfloat f);
 664   // dump a jdouble
 665   static void dump_double(DumpWriter* writer, jdouble d);
 666   // dumps the raw value of the given field
 667   static void dump_field_value(DumpWriter* writer, char type, oop obj, int offset);
 668   // returns the size of the static fields; also counts the static fields
 669   static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
 670   // dumps static fields of the given class
 671   static void dump_static_fields(DumpWriter* writer, Klass* k);
 672   // dump the raw values of the instance fields of the given object
 673   static void dump_instance_fields(DumpWriter* writer, oop o);
 674   // get the count of the instance fields for a given class
 675   static u2 get_instance_fields_count(InstanceKlass* ik);
 676   // dumps the definition of the instance fields for a given class
 677   static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k);
 678   // creates HPROF_GC_INSTANCE_DUMP record for the given object
 679   static void dump_instance(DumpWriter* writer, oop o);
 680   // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
 681   // array classes
 682   static void dump_class_and_array_classes(DumpWriter* writer, Klass* k);
 683   // creates HPROF_GC_CLASS_DUMP record for a given primitive array
 684   // class (and each multi-dimensional array class too)
 685   static void dump_basic_type_array_class(DumpWriter* writer, Klass* k);
 686 
 687   // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
 688   static void dump_object_array(DumpWriter* writer, objArrayOop array);
 689   // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
 690   static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
 691   // create HPROF_FRAME record for the given method and bci
 692   static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
 693 
 694   // check if we need to truncate an array
 695   static int calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size);
 696 
 697   // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
 698   static void end_of_dump(DumpWriter* writer);
 699 
 700   static oop mask_dormant_archived_object(oop o) {
 701     if (o != NULL && o->klass()->java_mirror() == NULL) {
 702       // Ignore this object since the corresponding java mirror is not loaded.
 703       // Might be a dormant archive object.
 704       return NULL;
 705     } else {
 706       return o;
 707     }
 708   }
 709 };
 710 
 711 // write a header of the given type
 712 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
 713   writer->write_u1((u1)tag);
 714   writer->write_u4(0);                  // current ticks
 715   writer->write_u4(len);
 716 }
 717 
 718 // returns hprof tag for the given type signature
 719 hprofTag DumperSupport::sig2tag(Symbol* sig) {
 720   switch (sig->char_at(0)) {
 721     case JVM_SIGNATURE_CLASS    : return HPROF_NORMAL_OBJECT;
 722     case JVM_SIGNATURE_ARRAY    : return HPROF_NORMAL_OBJECT;
 723     case JVM_SIGNATURE_BYTE     : return HPROF_BYTE;
 724     case JVM_SIGNATURE_CHAR     : return HPROF_CHAR;
 725     case JVM_SIGNATURE_FLOAT    : return HPROF_FLOAT;
 726     case JVM_SIGNATURE_DOUBLE   : return HPROF_DOUBLE;
 727     case JVM_SIGNATURE_INT      : return HPROF_INT;
 728     case JVM_SIGNATURE_LONG     : return HPROF_LONG;
 729     case JVM_SIGNATURE_SHORT    : return HPROF_SHORT;
 730     case JVM_SIGNATURE_BOOLEAN  : return HPROF_BOOLEAN;
 731     default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
 732   }
 733 }
 734 
 735 hprofTag DumperSupport::type2tag(BasicType type) {
 736   switch (type) {
 737     case T_BYTE     : return HPROF_BYTE;
 738     case T_CHAR     : return HPROF_CHAR;
 739     case T_FLOAT    : return HPROF_FLOAT;
 740     case T_DOUBLE   : return HPROF_DOUBLE;
 741     case T_INT      : return HPROF_INT;
 742     case T_LONG     : return HPROF_LONG;
 743     case T_SHORT    : return HPROF_SHORT;
 744     case T_BOOLEAN  : return HPROF_BOOLEAN;
 745     default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
 746   }
 747 }
 748 
 749 u4 DumperSupport::sig2size(Symbol* sig) {
 750   switch (sig->char_at(0)) {
 751     case JVM_SIGNATURE_CLASS:
 752     case JVM_SIGNATURE_ARRAY: return sizeof(address);
 753     case JVM_SIGNATURE_BOOLEAN:
 754     case JVM_SIGNATURE_BYTE: return 1;
 755     case JVM_SIGNATURE_SHORT:
 756     case JVM_SIGNATURE_CHAR: return 2;
 757     case JVM_SIGNATURE_INT:
 758     case JVM_SIGNATURE_FLOAT: return 4;
 759     case JVM_SIGNATURE_LONG:
 760     case JVM_SIGNATURE_DOUBLE: return 8;
 761     default: ShouldNotReachHere(); /* to shut up compiler */ return 0;
 762   }
 763 }
 764 
 765 // dump a jfloat
 766 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
 767   if (g_isnan(f)) {
 768     writer->write_u4(0x7fc00000);    // collapsing NaNs
 769   } else {
 770     union {
 771       int i;
 772       float f;
 773     } u;
 774     u.f = (float)f;
 775     writer->write_u4((u4)u.i);
 776   }
 777 }
 778 
 779 // dump a jdouble
 780 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
 781   union {
 782     jlong l;
 783     double d;
 784   } u;
 785   if (g_isnan(d)) {                 // collapsing NaNs
 786     u.l = (jlong)(0x7ff80000);
 787     u.l = (u.l << 32);
 788   } else {
 789     u.d = (double)d;
 790   }
 791   writer->write_u8((u8)u.l);
 792 }
 793 
 794 // dumps the raw value of the given field
 795 void DumperSupport::dump_field_value(DumpWriter* writer, char type, oop obj, int offset) {
 796   switch (type) {
 797     case JVM_SIGNATURE_CLASS :
 798     case JVM_SIGNATURE_ARRAY : {
 799       oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
 800       if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
 801         ResourceMark rm;
 802         log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
 803                              p2i(o), o->klass()->external_name(),
 804                              p2i(obj), obj->klass()->external_name());
 805       }
 806       o = mask_dormant_archived_object(o);
 807       assert(oopDesc::is_oop_or_null(o), "Expected an oop or NULL at " PTR_FORMAT, p2i(o));
 808       writer->write_objectID(o);
 809       break;
 810     }
 811     case JVM_SIGNATURE_BYTE : {
 812       jbyte b = obj->byte_field(offset);
 813       writer->write_u1((u1)b);
 814       break;
 815     }
 816     case JVM_SIGNATURE_CHAR : {
 817       jchar c = obj->char_field(offset);
 818       writer->write_u2((u2)c);
 819       break;
 820     }
 821     case JVM_SIGNATURE_SHORT : {
 822       jshort s = obj->short_field(offset);
 823       writer->write_u2((u2)s);
 824       break;
 825     }
 826     case JVM_SIGNATURE_FLOAT : {
 827       jfloat f = obj->float_field(offset);
 828       dump_float(writer, f);
 829       break;
 830     }
 831     case JVM_SIGNATURE_DOUBLE : {
 832       jdouble d = obj->double_field(offset);
 833       dump_double(writer, d);
 834       break;
 835     }
 836     case JVM_SIGNATURE_INT : {
 837       jint i = obj->int_field(offset);
 838       writer->write_u4((u4)i);
 839       break;
 840     }
 841     case JVM_SIGNATURE_LONG : {
 842       jlong l = obj->long_field(offset);
 843       writer->write_u8((u8)l);
 844       break;
 845     }
 846     case JVM_SIGNATURE_BOOLEAN : {
 847       jboolean b = obj->bool_field(offset);
 848       writer->write_u1((u1)b);
 849       break;
 850     }
 851     default : {
 852       ShouldNotReachHere();
 853       break;
 854     }
 855   }
 856 }
 857 
 858 // returns the size of the instance of the given class
 859 u4 DumperSupport::instance_size(Klass* k) {
 860   HandleMark hm;
 861   InstanceKlass* ik = InstanceKlass::cast(k);
 862   u4 size = 0;
 863 
 864   for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
 865     if (!fld.access_flags().is_static()) {
 866       size += sig2size(fld.signature());
 867     }
 868   }
 869   return size;
 870 }
 871 
 872 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
 873   HandleMark hm;
 874   field_count = 0;
 875   u4 size = 0;
 876 
 877   for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
 878     if (fldc.access_flags().is_static()) {
 879       field_count++;
 880       size += sig2size(fldc.signature());
 881     }
 882   }
 883 
 884   // Add in resolved_references which is referenced by the cpCache
 885   // The resolved_references is an array per InstanceKlass holding the
 886   // strings and other oops resolved from the constant pool.
 887   oop resolved_references = ik->constants()->resolved_references_or_null();
 888   if (resolved_references != NULL) {
 889     field_count++;
 890     size += sizeof(address);
 891 
 892     // Add in the resolved_references of the used previous versions of the class
 893     // in the case of RedefineClasses
 894     InstanceKlass* prev = ik->previous_versions();
 895     while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
 896       field_count++;
 897       size += sizeof(address);
 898       prev = prev->previous_versions();
 899     }
 900   }
 901 
 902   // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0]
 903   // arrays.
 904   oop init_lock = ik->init_lock();
 905   if (init_lock != NULL) {
 906     field_count++;
 907     size += sizeof(address);
 908   }
 909 
 910   // We write the value itself plus a name and a one byte type tag per field.
 911   return size + field_count * (sizeof(address) + 1);
 912 }
 913 
 914 // dumps static fields of the given class
 915 void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) {
 916   HandleMark hm;
 917   InstanceKlass* ik = InstanceKlass::cast(k);
 918 
 919   // dump the field descriptors and raw values
 920   for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
 921     if (fld.access_flags().is_static()) {
 922       Symbol* sig = fld.signature();
 923 
 924       writer->write_symbolID(fld.name());   // name
 925       writer->write_u1(sig2tag(sig));       // type
 926 
 927       // value
 928       dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
 929     }
 930   }
 931 
 932   // Add resolved_references for each class that has them
 933   oop resolved_references = ik->constants()->resolved_references_or_null();
 934   if (resolved_references != NULL) {
 935     writer->write_symbolID(vmSymbols::resolved_references_name());  // name
 936     writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
 937     writer->write_objectID(resolved_references);
 938 
 939     // Also write any previous versions
 940     InstanceKlass* prev = ik->previous_versions();
 941     while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
 942       writer->write_symbolID(vmSymbols::resolved_references_name());  // name
 943       writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
 944       writer->write_objectID(prev->constants()->resolved_references());
 945       prev = prev->previous_versions();
 946     }
 947   }
 948 
 949   // Add init lock to the end if the class is not yet initialized
 950   oop init_lock = ik->init_lock();
 951   if (init_lock != NULL) {
 952     writer->write_symbolID(vmSymbols::init_lock_name());         // name
 953     writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type
 954     writer->write_objectID(init_lock);
 955   }
 956 }
 957 
 958 // dump the raw values of the instance fields of the given object
 959 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
 960   HandleMark hm;
 961   InstanceKlass* ik = InstanceKlass::cast(o->klass());
 962 
 963   for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) {
 964     if (!fld.access_flags().is_static()) {
 965       Symbol* sig = fld.signature();
 966       dump_field_value(writer, sig->char_at(0), o, fld.offset());
 967     }
 968   }
 969 }
 970 
 971 // dumps the definition of the instance fields for a given class
 972 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
 973   HandleMark hm;
 974   u2 field_count = 0;
 975 
 976   for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) {
 977     if (!fldc.access_flags().is_static()) field_count++;
 978   }
 979 
 980   return field_count;
 981 }
 982 
 983 // dumps the definition of the instance fields for a given class
 984 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) {
 985   HandleMark hm;
 986   InstanceKlass* ik = InstanceKlass::cast(k);
 987 
 988   // dump the field descriptors
 989   for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) {
 990     if (!fld.access_flags().is_static()) {
 991       Symbol* sig = fld.signature();
 992 
 993       writer->write_symbolID(fld.name());   // name
 994       writer->write_u1(sig2tag(sig));       // type
 995     }
 996   }
 997 }
 998 
 999 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1000 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
1001   InstanceKlass* ik = InstanceKlass::cast(o->klass());
1002   u4 is = instance_size(ik);
1003   u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1004 
1005   writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1006   writer->write_objectID(o);
1007   writer->write_u4(STACK_TRACE_ID);
1008 
1009   // class ID
1010   writer->write_classID(ik);
1011 
1012   // number of bytes that follow
1013   writer->write_u4(is);
1014 
1015   // field values
1016   dump_instance_fields(writer, o);
1017 
1018   writer->end_sub_record();
1019 }
1020 
1021 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
1022 // its array classes
1023 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
1024   InstanceKlass* ik = InstanceKlass::cast(k);
1025 
1026   // We can safepoint and do a heap dump at a point where we have a Klass,
1027   // but no java mirror class has been setup for it. So we need to check
1028   // that the class is at least loaded, to avoid crash from a null mirror.
1029   if (!ik->is_loaded()) {
1030     return;
1031   }
1032 
1033   u2 static_fields_count = 0;
1034   u4 static_size = get_static_fields_size(ik, static_fields_count);
1035   u2 instance_fields_count = get_instance_fields_count(ik);
1036   u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1037   u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size;
1038 
1039   writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1040 
1041   // class ID
1042   writer->write_classID(ik);
1043   writer->write_u4(STACK_TRACE_ID);
1044 
1045   // super class ID
1046   InstanceKlass* java_super = ik->java_super();
1047   if (java_super == NULL) {
1048     writer->write_objectID(oop(NULL));
1049   } else {
1050     writer->write_classID(java_super);
1051   }
1052 
1053   writer->write_objectID(ik->class_loader());
1054   writer->write_objectID(ik->signers());
1055   writer->write_objectID(ik->protection_domain());
1056 
1057   // reserved
1058   writer->write_objectID(oop(NULL));
1059   writer->write_objectID(oop(NULL));
1060 
1061   // instance size
1062   writer->write_u4(DumperSupport::instance_size(ik));
1063 
1064   // size of constant pool - ignored by HAT 1.1
1065   writer->write_u2(0);
1066 
1067   // static fields
1068   writer->write_u2(static_fields_count);
1069   dump_static_fields(writer, ik);
1070 
1071   // description of instance fields
1072   writer->write_u2(instance_fields_count);
1073   dump_instance_field_descriptors(writer, ik);
1074 
1075   writer->end_sub_record();
1076 
1077   // array classes
1078   k = ik->array_klass_or_null();
1079   while (k != NULL) {
1080     assert(k->is_objArray_klass(), "not an ObjArrayKlass");
1081 
1082     u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1083     writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1084     writer->write_classID(k);
1085     writer->write_u4(STACK_TRACE_ID);
1086 
1087     // super class of array classes is java.lang.Object
1088     java_super = k->java_super();
1089     assert(java_super != NULL, "checking");
1090     writer->write_classID(java_super);
1091 
1092     writer->write_objectID(ik->class_loader());
1093     writer->write_objectID(ik->signers());
1094     writer->write_objectID(ik->protection_domain());
1095 
1096     writer->write_objectID(oop(NULL));    // reserved
1097     writer->write_objectID(oop(NULL));
1098     writer->write_u4(0);             // instance size
1099     writer->write_u2(0);             // constant pool
1100     writer->write_u2(0);             // static fields
1101     writer->write_u2(0);             // instance fields
1102 
1103     writer->end_sub_record();
1104 
1105     // get the array class for the next rank
1106     k = k->array_klass_or_null();
1107   }
1108 }
1109 
1110 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
1111 // class (and each multi-dimensional array class too)
1112 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) {
1113  // array classes
1114  while (k != NULL) {
1115     Klass* klass = k;
1116 
1117     u4 size = 1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + 2;
1118     writer->start_sub_record(HPROF_GC_CLASS_DUMP, size);
1119     writer->write_classID(klass);
1120     writer->write_u4(STACK_TRACE_ID);
1121 
1122     // super class of array classes is java.lang.Object
1123     InstanceKlass* java_super = klass->java_super();
1124     assert(java_super != NULL, "checking");
1125     writer->write_classID(java_super);
1126 
1127     writer->write_objectID(oop(NULL));    // loader
1128     writer->write_objectID(oop(NULL));    // signers
1129     writer->write_objectID(oop(NULL));    // protection domain
1130 
1131     writer->write_objectID(oop(NULL));    // reserved
1132     writer->write_objectID(oop(NULL));
1133     writer->write_u4(0);             // instance size
1134     writer->write_u2(0);             // constant pool
1135     writer->write_u2(0);             // static fields
1136     writer->write_u2(0);             // instance fields
1137 
1138     writer->end_sub_record();
1139 
1140     // get the array class for the next rank
1141     k = klass->array_klass_or_null();
1142   }
1143 }
1144 
1145 // Hprof uses an u4 as record length field,
1146 // which means we need to truncate arrays that are too long.
1147 int DumperSupport::calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size) {
1148   BasicType type = ArrayKlass::cast(array->klass())->element_type();
1149   assert(type >= T_BOOLEAN && type <= T_OBJECT, "invalid array element type");
1150 
1151   int length = array->length();
1152 
1153   int type_size;
1154   if (type == T_OBJECT) {
1155     type_size = sizeof(address);
1156   } else {
1157     type_size = type2aelembytes(type);
1158   }
1159 
1160   size_t length_in_bytes = (size_t)length * type_size;
1161   uint max_bytes = max_juint - header_size;
1162 
1163   if (length_in_bytes > max_bytes) {
1164     length = max_bytes / type_size;
1165     length_in_bytes = (size_t)length * type_size;
1166 
1167     warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1168             type2name_tab[type], array->length(), length);
1169   }
1170   return length;
1171 }
1172 
1173 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1174 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
1175   // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1176   short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1177   int length = calculate_array_max_length(writer, array, header_size);
1178   u4 size = header_size + length * sizeof(address);
1179 
1180   writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1181   writer->write_objectID(array);
1182   writer->write_u4(STACK_TRACE_ID);
1183   writer->write_u4(length);
1184 
1185   // array class ID
1186   writer->write_classID(array->klass());
1187 
1188   // [id]* elements
1189   for (int index = 0; index < length; index++) {
1190     oop o = array->obj_at(index);
1191     if (o != NULL && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == NULL) {
1192       ResourceMark rm;
1193       log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1194                            p2i(o), o->klass()->external_name(),
1195                            p2i(array), array->klass()->external_name());
1196     }
1197     o = mask_dormant_archived_object(o);
1198     writer->write_objectID(o);
1199   }
1200 
1201   writer->end_sub_record();
1202 }
1203 
1204 #define WRITE_ARRAY(Array, Type, Size, Length) \
1205   for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1206 
1207 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1208 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
1209   BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1210 
1211   // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1212   short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1213 
1214   int length = calculate_array_max_length(writer, array, header_size);
1215   int type_size = type2aelembytes(type);
1216   u4 length_in_bytes = (u4)length * type_size;
1217   u4 size = header_size + length_in_bytes;
1218 
1219   writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1220   writer->write_objectID(array);
1221   writer->write_u4(STACK_TRACE_ID);
1222   writer->write_u4(length);
1223   writer->write_u1(type2tag(type));
1224 
1225   // nothing to copy
1226   if (length == 0) {
1227     writer->end_sub_record();
1228     return;
1229   }
1230 
1231   // If the byte ordering is big endian then we can copy most types directly
1232 
1233   switch (type) {
1234     case T_INT : {
1235       if (Endian::is_Java_byte_ordering_different()) {
1236         WRITE_ARRAY(array, int, u4, length);
1237       } else {
1238         writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
1239       }
1240       break;
1241     }
1242     case T_BYTE : {
1243       writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
1244       break;
1245     }
1246     case T_CHAR : {
1247       if (Endian::is_Java_byte_ordering_different()) {
1248         WRITE_ARRAY(array, char, u2, length);
1249       } else {
1250         writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
1251       }
1252       break;
1253     }
1254     case T_SHORT : {
1255       if (Endian::is_Java_byte_ordering_different()) {
1256         WRITE_ARRAY(array, short, u2, length);
1257       } else {
1258         writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
1259       }
1260       break;
1261     }
1262     case T_BOOLEAN : {
1263       if (Endian::is_Java_byte_ordering_different()) {
1264         WRITE_ARRAY(array, bool, u1, length);
1265       } else {
1266         writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
1267       }
1268       break;
1269     }
1270     case T_LONG : {
1271       if (Endian::is_Java_byte_ordering_different()) {
1272         WRITE_ARRAY(array, long, u8, length);
1273       } else {
1274         writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
1275       }
1276       break;
1277     }
1278 
1279     // handle float/doubles in a special value to ensure than NaNs are
1280     // written correctly. TO DO: Check if we can avoid this on processors that
1281     // use IEEE 754.
1282 
1283     case T_FLOAT : {
1284       for (int i = 0; i < length; i++) {
1285         dump_float(writer, array->float_at(i));
1286       }
1287       break;
1288     }
1289     case T_DOUBLE : {
1290       for (int i = 0; i < length; i++) {
1291         dump_double(writer, array->double_at(i));
1292       }
1293       break;
1294     }
1295     default : ShouldNotReachHere();
1296   }
1297 
1298   writer->end_sub_record();
1299 }
1300 
1301 // create a HPROF_FRAME record of the given Method* and bci
1302 void DumperSupport::dump_stack_frame(DumpWriter* writer,
1303                                      int frame_serial_num,
1304                                      int class_serial_num,
1305                                      Method* m,
1306                                      int bci) {
1307   int line_number;
1308   if (m->is_native()) {
1309     line_number = -3;  // native frame
1310   } else {
1311     line_number = m->line_number_from_bci(bci);
1312   }
1313 
1314   write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1315   writer->write_id(frame_serial_num);               // frame serial number
1316   writer->write_symbolID(m->name());                // method's name
1317   writer->write_symbolID(m->signature());           // method's signature
1318 
1319   assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1320   writer->write_symbolID(m->method_holder()->source_file_name());  // source file name
1321   writer->write_u4(class_serial_num);               // class serial number
1322   writer->write_u4((u4) line_number);               // line number
1323 }
1324 
1325 
1326 // Support class used to generate HPROF_UTF8 records from the entries in the
1327 // SymbolTable.
1328 
1329 class SymbolTableDumper : public SymbolClosure {
1330  private:
1331   DumpWriter* _writer;
1332   DumpWriter* writer() const                { return _writer; }
1333  public:
1334   SymbolTableDumper(DumpWriter* writer)     { _writer = writer; }
1335   void do_symbol(Symbol** p);
1336 };
1337 
1338 void SymbolTableDumper::do_symbol(Symbol** p) {
1339   ResourceMark rm;
1340   Symbol* sym = load_symbol(p);
1341   int len = sym->utf8_length();
1342   if (len > 0) {
1343     char* s = sym->as_utf8();
1344     DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1345     writer()->write_symbolID(sym);
1346     writer()->write_raw(s, len);
1347   }
1348 }
1349 
1350 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
1351 
1352 class JNILocalsDumper : public OopClosure {
1353  private:
1354   DumpWriter* _writer;
1355   u4 _thread_serial_num;
1356   int _frame_num;
1357   DumpWriter* writer() const                { return _writer; }
1358  public:
1359   JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
1360     _writer = writer;
1361     _thread_serial_num = thread_serial_num;
1362     _frame_num = -1;  // default - empty stack
1363   }
1364   void set_frame_number(int n) { _frame_num = n; }
1365   void do_oop(oop* obj_p);
1366   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1367 };
1368 
1369 
1370 void JNILocalsDumper::do_oop(oop* obj_p) {
1371   // ignore null handles
1372   oop o = *obj_p;
1373   if (o != NULL) {
1374     u4 size = 1 + sizeof(address) + 4 + 4;
1375     writer()->start_sub_record(HPROF_GC_ROOT_JNI_LOCAL, size);
1376     writer()->write_objectID(o);
1377     writer()->write_u4(_thread_serial_num);
1378     writer()->write_u4((u4)_frame_num);
1379     writer()->end_sub_record();
1380   }
1381 }
1382 
1383 
1384 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
1385 
1386 class JNIGlobalsDumper : public OopClosure {
1387  private:
1388   DumpWriter* _writer;
1389   DumpWriter* writer() const                { return _writer; }
1390 
1391  public:
1392   JNIGlobalsDumper(DumpWriter* writer) {
1393     _writer = writer;
1394   }
1395   void do_oop(oop* obj_p);
1396   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1397 };
1398 
1399 void JNIGlobalsDumper::do_oop(oop* obj_p) {
1400   oop o = *obj_p;
1401 
1402   // ignore these
1403   if (o == NULL) return;
1404 
1405   // we ignore global ref to symbols and other internal objects
1406   if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
1407     u4 size = 1 + 2 * sizeof(address);
1408     writer()->start_sub_record(HPROF_GC_ROOT_JNI_GLOBAL, size);
1409     writer()->write_objectID(o);
1410     writer()->write_objectID((oopDesc*)obj_p);      // global ref ID
1411     writer()->end_sub_record();
1412   }
1413 };
1414 
1415 
1416 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
1417 
1418 class MonitorUsedDumper : public OopClosure {
1419  private:
1420   DumpWriter* _writer;
1421   DumpWriter* writer() const                { return _writer; }
1422  public:
1423   MonitorUsedDumper(DumpWriter* writer) {
1424     _writer = writer;
1425   }
1426   void do_oop(oop* obj_p) {
1427     u4 size = 1 + sizeof(address);
1428     writer()->start_sub_record(HPROF_GC_ROOT_MONITOR_USED, size);
1429     writer()->write_objectID(*obj_p);
1430     writer()->end_sub_record();
1431   }
1432   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
1433 };
1434 
1435 
1436 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
1437 
1438 class StickyClassDumper : public KlassClosure {
1439  private:
1440   DumpWriter* _writer;
1441   DumpWriter* writer() const                { return _writer; }
1442  public:
1443   StickyClassDumper(DumpWriter* writer) {
1444     _writer = writer;
1445   }
1446   void do_klass(Klass* k) {
1447     if (k->is_instance_klass()) {
1448       InstanceKlass* ik = InstanceKlass::cast(k);
1449       u4 size = 1 + sizeof(address);
1450       writer()->start_sub_record(HPROF_GC_ROOT_STICKY_CLASS, size);
1451       writer()->write_classID(ik);
1452       writer()->end_sub_record();
1453     }
1454   }
1455 };
1456 
1457 
1458 class VM_HeapDumper;
1459 
1460 // Support class using when iterating over the heap.
1461 
1462 class HeapObjectDumper : public ObjectClosure {
1463  private:
1464   VM_HeapDumper* _dumper;
1465   DumpWriter* _writer;
1466 
1467   VM_HeapDumper* dumper()               { return _dumper; }
1468   DumpWriter* writer()                  { return _writer; }
1469 
1470  public:
1471   HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
1472     _dumper = dumper;
1473     _writer = writer;
1474   }
1475 
1476   // called for each object in the heap
1477   void do_object(oop o);
1478 };
1479 
1480 void HeapObjectDumper::do_object(oop o) {
1481   // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
1482   if (o->klass() == SystemDictionary::Class_klass()) {
1483     if (!java_lang_Class::is_primitive(o)) {
1484       return;
1485     }
1486   }
1487 
1488   if (DumperSupport::mask_dormant_archived_object(o) == NULL) {
1489     log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)", p2i(o), o->klass()->external_name());
1490     return;
1491   }
1492 
1493   if (o->is_instance()) {
1494     // create a HPROF_GC_INSTANCE record for each object
1495     DumperSupport::dump_instance(writer(), o);
1496   } else if (o->is_objArray()) {
1497     // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
1498     DumperSupport::dump_object_array(writer(), objArrayOop(o));
1499   } else if (o->is_typeArray()) {
1500     // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
1501     DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
1502   }
1503 }
1504 
1505 // The VM operation that performs the heap dump
1506 class VM_HeapDumper : public VM_GC_Operation {
1507  private:
1508   static VM_HeapDumper* _global_dumper;
1509   static DumpWriter*    _global_writer;
1510   DumpWriter*           _local_writer;
1511   JavaThread*           _oome_thread;
1512   Method*               _oome_constructor;
1513   bool _gc_before_heap_dump;
1514   GrowableArray<Klass*>* _klass_map;
1515   ThreadStackTrace** _stack_traces;
1516   int _num_threads;
1517 
1518   // accessors and setters
1519   static VM_HeapDumper* dumper()         {  assert(_global_dumper != NULL, "Error"); return _global_dumper; }
1520   static DumpWriter* writer()            {  assert(_global_writer != NULL, "Error"); return _global_writer; }
1521   void set_global_dumper() {
1522     assert(_global_dumper == NULL, "Error");
1523     _global_dumper = this;
1524   }
1525   void set_global_writer() {
1526     assert(_global_writer == NULL, "Error");
1527     _global_writer = _local_writer;
1528   }
1529   void clear_global_dumper() { _global_dumper = NULL; }
1530   void clear_global_writer() { _global_writer = NULL; }
1531 
1532   bool skip_operation() const;
1533 
1534   // writes a HPROF_LOAD_CLASS record
1535   class ClassesDo;
1536   static void do_load_class(Klass* k);
1537 
1538   // writes a HPROF_GC_CLASS_DUMP record for the given class
1539   // (and each array class too)
1540   static void do_class_dump(Klass* k);
1541 
1542   // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1543   // array (and each multi-dimensional array too)
1544   static void do_basic_type_array_class_dump(Klass* k);
1545 
1546   // HPROF_GC_ROOT_THREAD_OBJ records
1547   int do_thread(JavaThread* thread, u4 thread_serial_num);
1548   void do_threads();
1549 
1550   void add_class_serial_number(Klass* k, int serial_num) {
1551     _klass_map->at_put_grow(serial_num, k);
1552   }
1553 
1554   // HPROF_TRACE and HPROF_FRAME records
1555   void dump_stack_traces();
1556 
1557  public:
1558   VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
1559     VM_GC_Operation(0 /* total collections,      dummy, ignored */,
1560                     GCCause::_heap_dump /* GC Cause */,
1561                     0 /* total full collections, dummy, ignored */,
1562                     gc_before_heap_dump) {

1563     _local_writer = writer;
1564     _gc_before_heap_dump = gc_before_heap_dump;
1565     _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
1566     _stack_traces = NULL;
1567     _num_threads = 0;
1568     if (oome) {
1569       assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
1570       // get OutOfMemoryError zero-parameter constructor
1571       InstanceKlass* oome_ik = SystemDictionary::OutOfMemoryError_klass();
1572       _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
1573                                                           vmSymbols::void_method_signature());
1574       // get thread throwing OOME when generating the heap dump at OOME
1575       _oome_thread = JavaThread::current();
1576     } else {
1577       _oome_thread = NULL;
1578       _oome_constructor = NULL;
1579     }
1580   }
1581   ~VM_HeapDumper() {
1582     if (_stack_traces != NULL) {
1583       for (int i=0; i < _num_threads; i++) {
1584         delete _stack_traces[i];
1585       }
1586       FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces);
1587     }
1588     delete _klass_map;
1589   }
1590 
1591   VMOp_Type type() const { return VMOp_HeapDumper; }
1592   void doit();

1593 };
1594 

1595 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
1596 DumpWriter*    VM_HeapDumper::_global_writer = NULL;
1597 
1598 bool VM_HeapDumper::skip_operation() const {
1599   return false;
1600 }
1601 
1602 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
1603 void DumperSupport::end_of_dump(DumpWriter* writer) {
1604   writer->finish_dump_segment();
1605 
1606   writer->write_u1(HPROF_HEAP_DUMP_END);
1607   writer->write_u4(0);
1608   writer->write_u4(0);
1609 }
1610 
1611 // writes a HPROF_LOAD_CLASS record for the class (and each of its
1612 // array classes)
1613 void VM_HeapDumper::do_load_class(Klass* k) {
1614   static u4 class_serial_num = 0;
1615 
1616   // len of HPROF_LOAD_CLASS record
1617   u4 remaining = 2*oopSize + 2*sizeof(u4);
1618 
1619   // write a HPROF_LOAD_CLASS for the class and each array class
1620   do {
1621     DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
1622 
1623     // class serial number is just a number
1624     writer()->write_u4(++class_serial_num);
1625 
1626     // class ID
1627     Klass* klass = k;
1628     writer()->write_classID(klass);
1629 
1630     // add the Klass* and class serial number pair
1631     dumper()->add_class_serial_number(klass, class_serial_num);
1632 
1633     writer()->write_u4(STACK_TRACE_ID);
1634 
1635     // class name ID
1636     Symbol* name = klass->name();
1637     writer()->write_symbolID(name);
1638 
1639     // write a LOAD_CLASS record for the array type (if it exists)
1640     k = klass->array_klass_or_null();
1641   } while (k != NULL);
1642 }
1643 
1644 // writes a HPROF_GC_CLASS_DUMP record for the given class
1645 void VM_HeapDumper::do_class_dump(Klass* k) {
1646   if (k->is_instance_klass()) {
1647     DumperSupport::dump_class_and_array_classes(writer(), k);
1648   }
1649 }
1650 
1651 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
1652 // array (and each multi-dimensional array too)
1653 void VM_HeapDumper::do_basic_type_array_class_dump(Klass* k) {
1654   DumperSupport::dump_basic_type_array_class(writer(), k);
1655 }
1656 
1657 // Walk the stack of the given thread.
1658 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
1659 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
1660 //
1661 // It returns the number of Java frames in this thread stack
1662 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
1663   JNILocalsDumper blk(writer(), thread_serial_num);
1664 
1665   oop threadObj = java_thread->threadObj();
1666   assert(threadObj != NULL, "sanity check");
1667 
1668   int stack_depth = 0;
1669   if (java_thread->has_last_Java_frame()) {
1670 
1671     // vframes are resource allocated
1672     Thread* current_thread = Thread::current();
1673     ResourceMark rm(current_thread);
1674     HandleMark hm(current_thread);
1675 
1676     RegisterMap reg_map(java_thread);
1677     frame f = java_thread->last_frame();
1678     vframe* vf = vframe::new_vframe(&f, &reg_map, java_thread);
1679     frame* last_entry_frame = NULL;
1680     int extra_frames = 0;
1681 
1682     if (java_thread == _oome_thread && _oome_constructor != NULL) {
1683       extra_frames++;
1684     }
1685     while (vf != NULL) {
1686       blk.set_frame_number(stack_depth);
1687       if (vf->is_java_frame()) {
1688 
1689         // java frame (interpreted, compiled, ...)
1690         javaVFrame *jvf = javaVFrame::cast(vf);
1691         if (!(jvf->method()->is_native())) {
1692           StackValueCollection* locals = jvf->locals();
1693           for (int slot=0; slot<locals->size(); slot++) {
1694             if (locals->at(slot)->type() == T_OBJECT) {
1695               oop o = locals->obj_at(slot)();
1696 
1697               if (o != NULL) {
1698                 u4 size = 1 + sizeof(address) + 4 + 4;
1699                 writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
1700                 writer()->write_objectID(o);
1701                 writer()->write_u4(thread_serial_num);
1702                 writer()->write_u4((u4) (stack_depth + extra_frames));
1703                 writer()->end_sub_record();
1704               }
1705             }
1706           }
1707           StackValueCollection *exprs = jvf->expressions();
1708           for(int index = 0; index < exprs->size(); index++) {
1709             if (exprs->at(index)->type() == T_OBJECT) {
1710                oop o = exprs->obj_at(index)();
1711                if (o != NULL) {
1712                  u4 size = 1 + sizeof(address) + 4 + 4;
1713                  writer()->start_sub_record(HPROF_GC_ROOT_JAVA_FRAME, size);
1714                  writer()->write_objectID(o);
1715                  writer()->write_u4(thread_serial_num);
1716                  writer()->write_u4((u4) (stack_depth + extra_frames));
1717                  writer()->end_sub_record();
1718                }
1719              }
1720           }
1721         } else {
1722           // native frame
1723           if (stack_depth == 0) {
1724             // JNI locals for the top frame.
1725             java_thread->active_handles()->oops_do(&blk);
1726           } else {
1727             if (last_entry_frame != NULL) {
1728               // JNI locals for the entry frame
1729               assert(last_entry_frame->is_entry_frame(), "checking");
1730               last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
1731             }
1732           }
1733         }
1734         // increment only for Java frames
1735         stack_depth++;
1736         last_entry_frame = NULL;
1737 
1738       } else {
1739         // externalVFrame - if it's an entry frame then report any JNI locals
1740         // as roots when we find the corresponding native javaVFrame
1741         frame* fr = vf->frame_pointer();
1742         assert(fr != NULL, "sanity check");
1743         if (fr->is_entry_frame()) {
1744           last_entry_frame = fr;
1745         }
1746       }
1747       vf = vf->sender();
1748     }
1749   } else {
1750     // no last java frame but there may be JNI locals
1751     java_thread->active_handles()->oops_do(&blk);
1752   }
1753   return stack_depth;
1754 }
1755 
1756 
1757 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
1758 // the stack so that locals and JNI locals are dumped.
1759 void VM_HeapDumper::do_threads() {
1760   for (int i=0; i < _num_threads; i++) {
1761     JavaThread* thread = _stack_traces[i]->thread();
1762     oop threadObj = thread->threadObj();
1763     u4 thread_serial_num = i+1;
1764     u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
1765     u4 size = 1 + sizeof(address) + 4 + 4;
1766     writer()->start_sub_record(HPROF_GC_ROOT_THREAD_OBJ, size);
1767     writer()->write_objectID(threadObj);
1768     writer()->write_u4(thread_serial_num);  // thread number
1769     writer()->write_u4(stack_serial_num);   // stack trace serial number
1770     writer()->end_sub_record();
1771     int num_frames = do_thread(thread, thread_serial_num);
1772     assert(num_frames == _stack_traces[i]->get_stack_depth(),
1773            "total number of Java frames not matched");
1774   }
1775 }
1776 
1777 
1778 // The VM operation that dumps the heap. The dump consists of the following
1779 // records:
1780 //
1781 //  HPROF_HEADER
1782 //  [HPROF_UTF8]*
1783 //  [HPROF_LOAD_CLASS]*
1784 //  [[HPROF_FRAME]*|HPROF_TRACE]*
1785 //  [HPROF_GC_CLASS_DUMP]*
1786 //  [HPROF_HEAP_DUMP_SEGMENT]*
1787 //  HPROF_HEAP_DUMP_END
1788 //
1789 // The HPROF_TRACE records represent the stack traces where the heap dump
1790 // is generated and a "dummy trace" record which does not include
1791 // any frames. The dummy trace record is used to be referenced as the
1792 // unknown object alloc site.
1793 //
1794 // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records.
1795 // To allow the heap dump be generated in a single pass we remember the position
1796 // of the dump length and fix it up after all sub-records have been written.
1797 // To generate the sub-records we iterate over the heap, writing
1798 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
1799 // records as we go. Once that is done we write records for some of the GC
1800 // roots.
1801 
1802 void VM_HeapDumper::doit() {
1803 
1804   HandleMark hm;
1805   CollectedHeap* ch = Universe::heap();
1806 
1807   ch->ensure_parsability(false); // must happen, even if collection does
1808                                  // not happen (e.g. due to GCLocker)
1809 
1810   if (_gc_before_heap_dump) {
1811     if (GCLocker::is_active()) {
1812       warning("GC locker is held; pre-heapdump GC was skipped");
1813     } else {
1814       ch->collect_as_vm_thread(GCCause::_heap_dump);
1815     }
1816   }
1817 
1818   // At this point we should be the only dumper active, so
1819   // the following should be safe.
1820   set_global_dumper();
1821   set_global_writer();
1822 
1823   // Write the file header - we always use 1.0.2
1824   size_t used = ch->used();


















1825   const char* header = "JAVA PROFILE 1.0.2";
1826 
1827   // header is few bytes long - no chance to overflow int
1828   writer()->write_raw((void*)header, (int)strlen(header));
1829   writer()->write_u1(0); // terminator
1830   writer()->write_u4(oopSize);
1831   // timestamp is current time in ms
1832   writer()->write_u8(os::javaTimeMillis());
1833 
1834   // HPROF_UTF8 records
1835   SymbolTableDumper sym_dumper(writer());
1836   SymbolTable::symbols_do(&sym_dumper);
1837 
1838   // write HPROF_LOAD_CLASS records
1839   {
1840     LockedClassesDo locked_load_classes(&do_load_class);
1841     ClassLoaderDataGraph::classes_do(&locked_load_classes);
1842   }
1843   Universe::basic_type_classes_do(&do_load_class);
1844 
1845   // write HPROF_FRAME and HPROF_TRACE records
1846   // this must be called after _klass_map is built when iterating the classes above.
1847   dump_stack_traces();
1848 
1849   // Writes HPROF_GC_CLASS_DUMP records
1850   {
1851     LockedClassesDo locked_dump_class(&do_class_dump);
1852     ClassLoaderDataGraph::classes_do(&locked_dump_class);
1853   }
1854   Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
1855 
1856   // writes HPROF_GC_INSTANCE_DUMP records.
1857   // After each sub-record is written check_segment_length will be invoked
1858   // to check if the current segment exceeds a threshold. If so, a new
1859   // segment is started.
1860   // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
1861   // of the heap dump.
1862   HeapObjectDumper obj_dumper(this, writer());
1863   Universe::heap()->object_iterate(&obj_dumper);
1864 
1865   // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
1866   do_threads();
1867 
1868   // HPROF_GC_ROOT_MONITOR_USED
1869   MonitorUsedDumper mon_dumper(writer());
1870   ObjectSynchronizer::oops_do(&mon_dumper);
1871 
1872   // HPROF_GC_ROOT_JNI_GLOBAL
1873   JNIGlobalsDumper jni_dumper(writer());
1874   JNIHandles::oops_do(&jni_dumper);
1875   Universe::oops_do(&jni_dumper);  // technically not jni roots, but global roots
1876                                    // for things like preallocated throwable backtraces
1877 
1878   // HPROF_GC_ROOT_STICKY_CLASS
1879   // These should be classes in the NULL class loader data, and not all classes
1880   // if !ClassUnloading
1881   StickyClassDumper class_dumper(writer());
1882   ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper);
1883 
1884   // Writes the HPROF_HEAP_DUMP_END record.
1885   DumperSupport::end_of_dump(writer());
1886 
1887   // Now we clear the global variables, so that a future dumper might run.
1888   clear_global_dumper();
1889   clear_global_writer();
1890 }
1891 
1892 void VM_HeapDumper::dump_stack_traces() {
1893   // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
1894   DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
1895   writer()->write_u4((u4) STACK_TRACE_ID);
1896   writer()->write_u4(0);                    // thread number
1897   writer()->write_u4(0);                    // frame count
1898 
1899   _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal);
1900   int frame_serial_num = 0;
1901   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1902     oop threadObj = thread->threadObj();
1903     if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
1904       // dump thread stack trace

1905       ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
1906       stack_trace->dump_stack_at_safepoint(-1);
1907       _stack_traces[_num_threads++] = stack_trace;
1908 
1909       // write HPROF_FRAME records for this thread's stack trace
1910       int depth = stack_trace->get_stack_depth();
1911       int thread_frame_start = frame_serial_num;
1912       int extra_frames = 0;
1913       // write fake frame that makes it look like the thread, which caused OOME,
1914       // is in the OutOfMemoryError zero-parameter constructor
1915       if (thread == _oome_thread && _oome_constructor != NULL) {
1916         int oome_serial_num = _klass_map->find(_oome_constructor->method_holder());
1917         // the class serial number starts from 1
1918         assert(oome_serial_num > 0, "OutOfMemoryError class not found");
1919         DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
1920                                         _oome_constructor, 0);
1921         extra_frames++;
1922       }
1923       for (int j=0; j < depth; j++) {
1924         StackFrameInfo* frame = stack_trace->stack_frame_at(j);
1925         Method* m = frame->method();
1926         int class_serial_num = _klass_map->find(m->method_holder());
1927         // the class serial number starts from 1
1928         assert(class_serial_num > 0, "class not found");
1929         DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
1930       }
1931       depth += extra_frames;
1932 
1933       // write HPROF_TRACE record for one thread
1934       DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
1935       int stack_serial_num = _num_threads + STACK_TRACE_ID;
1936       writer()->write_u4(stack_serial_num);      // stack trace serial number
1937       writer()->write_u4((u4) _num_threads);     // thread serial number
1938       writer()->write_u4(depth);                 // frame count
1939       for (int j=1; j <= depth; j++) {
1940         writer()->write_id(thread_frame_start + j);
1941       }
1942     }
1943   }
1944 }
1945 
1946 // dump the heap to given path.
1947 int HeapDumper::dump(const char* path, outputStream* out) {
1948   assert(path != NULL && strlen(path) > 0, "path missing");
1949 
1950   // print message in interactive case
1951   if (out != NULL) {
1952     out->print_cr("Dumping heap to %s ...", path);
1953     timer()->start();
1954   }
1955 
1956   // create JFR event
1957   EventHeapDump event;
1958 
1959   // create the dump writer. If the file can be opened then bail
1960   DumpWriter writer(path);











1961   if (writer.error() != NULL) {
1962     set_error(writer.error());
1963     if (out != NULL) {
1964       out->print_cr("Unable to create %s: %s", path,
1965         (error() != NULL) ? error() : "reason unknown");
1966     }
1967     return -1;
1968   }
1969 
1970   // generate the dump
1971   VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
1972   if (Thread::current()->is_VM_thread()) {
1973     assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
1974     dumper.doit();
1975   } else {
1976     VMThread::execute(&dumper);
1977   }
1978 
1979   // close dump file and record any error that the writer may have encountered
1980   writer.close();
1981   set_error(writer.error());
1982 
1983   // emit JFR event
1984   if (error() == NULL) {
1985     event.set_destination(path);
1986     event.set_gcBeforeDump(_gc_before_heap_dump);
1987     event.set_size(writer.bytes_written());
1988     event.set_onOutOfMemoryError(_oome);
1989     event.commit();
1990   }
1991 
1992   // print message in interactive case
1993   if (out != NULL) {
1994     timer()->stop();
1995     if (error() == NULL) {
1996       out->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
1997                     writer.bytes_written(), timer()->seconds());
1998     } else {
1999       out->print_cr("Dump file is incomplete: %s", writer.error());
2000     }
2001   }
2002 
2003   return (writer.error() == NULL) ? 0 : -1;
2004 }
2005 
2006 // stop timer (if still active), and free any error string we might be holding
2007 HeapDumper::~HeapDumper() {
2008   if (timer()->is_active()) {
2009     timer()->stop();
2010   }
2011   set_error(NULL);
2012 }
2013 
2014 
2015 // returns the error string (resource allocated), or NULL
2016 char* HeapDumper::error_as_C_string() const {
2017   if (error() != NULL) {
2018     char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
2019     strcpy(str, error());
2020     return str;
2021   } else {
2022     return NULL;
2023   }
2024 }
2025 
2026 // set the error string
2027 void HeapDumper::set_error(char* error) {
2028   if (_error != NULL) {
2029     os::free(_error);
2030   }
2031   if (error == NULL) {
2032     _error = NULL;
2033   } else {
2034     _error = os::strdup(error);
2035     assert(_error != NULL, "allocation failure");
2036   }
2037 }
2038 
2039 // Called by out-of-memory error reporting by a single Java thread
2040 // outside of a JVM safepoint
2041 void HeapDumper::dump_heap_from_oome() {
2042   HeapDumper::dump_heap(true);
2043 }
2044 
2045 // Called by error reporting by a single Java thread outside of a JVM safepoint,
2046 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
2047 // callers are strictly serialized and guaranteed not to interfere below. For more
2048 // general use, however, this method will need modification to prevent
2049 // inteference when updating the static variables base_path and dump_file_seq below.
2050 void HeapDumper::dump_heap() {
2051   HeapDumper::dump_heap(false);
2052 }
2053 
2054 void HeapDumper::dump_heap(bool oome) {
2055   static char base_path[JVM_MAXPATHLEN] = {'\0'};
2056   static uint dump_file_seq = 0;
2057   char* my_path;
2058   const int max_digit_chars = 20;
2059 
2060   const char* dump_file_name = "java_pid";
2061   const char* dump_file_ext  = ".hprof";
2062 
2063   // The dump file defaults to java_pid<pid>.hprof in the current working
2064   // directory. HeapDumpPath=<file> can be used to specify an alternative
2065   // dump file name or a directory where dump file is created.
2066   if (dump_file_seq == 0) { // first time in, we initialize base_path
2067     // Calculate potentially longest base path and check if we have enough
2068     // allocated statically.
2069     const size_t total_length =
2070                       (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
2071                       strlen(os::file_separator()) + max_digit_chars +
2072                       strlen(dump_file_name) + strlen(dump_file_ext) + 1;
2073     if (total_length > sizeof(base_path)) {
2074       warning("Cannot create heap dump file.  HeapDumpPath is too long.");
2075       return;
2076     }
2077 
2078     bool use_default_filename = true;
2079     if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
2080       // HeapDumpPath=<file> not specified
2081     } else {
2082       strcpy(base_path, HeapDumpPath);
2083       // check if the path is a directory (must exist)
2084       DIR* dir = os::opendir(base_path);
2085       if (dir == NULL) {
2086         use_default_filename = false;
2087       } else {
2088         // HeapDumpPath specified a directory. We append a file separator
2089         // (if needed).
2090         os::closedir(dir);
2091         size_t fs_len = strlen(os::file_separator());
2092         if (strlen(base_path) >= fs_len) {
2093           char* end = base_path;
2094           end += (strlen(base_path) - fs_len);
2095           if (strcmp(end, os::file_separator()) != 0) {
2096             strcat(base_path, os::file_separator());
2097           }
2098         }
2099       }
2100     }
2101     // If HeapDumpPath wasn't a file name then we append the default name
2102     if (use_default_filename) {
2103       const size_t dlen = strlen(base_path);  // if heap dump dir specified
2104       jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
2105                    dump_file_name, os::current_process_id(), dump_file_ext);
2106     }
2107     const size_t len = strlen(base_path) + 1;
2108     my_path = (char*)os::malloc(len, mtInternal);
2109     if (my_path == NULL) {
2110       warning("Cannot create heap dump file.  Out of system memory.");
2111       return;
2112     }
2113     strncpy(my_path, base_path, len);
2114   } else {
2115     // Append a sequence number id for dumps following the first
2116     const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
2117     my_path = (char*)os::malloc(len, mtInternal);
2118     if (my_path == NULL) {
2119       warning("Cannot create heap dump file.  Out of system memory.");
2120       return;
2121     }
2122     jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
2123   }
2124   dump_file_seq++;   // increment seq number for next time we dump
2125 
2126   HeapDumper dumper(false /* no GC before heap dump */,
2127                     oome  /* pass along out-of-memory-error flag */);
2128   dumper.dump(my_path, tty);
2129   os::free(my_path);
2130 }
--- EOF ---