jdk8-mips64-public/hotspot: src/share/vm/services/heapDumper.cpp@04d83ba48607 (annotated)

src/share/vm/services/heapDumper.cpp@04d83ba48607 (annotated)

src/share/vm/services/heapDumper.cpp

Thu, 24 May 2018 17:06:56 +0800

author: aoqi
date: Thu, 24 May 2018 17:06:56 +0800
changeset 8604: 04d83ba48607
parent 8420: b5c3e9670fa0
parent 6876: 710a3c8b516e
child 9448: 73d689add964
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "classfile/symbolTable.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "gc_implementation/shared/vmGCOperations.hpp"
 #include "memory/gcLocker.inline.hpp"
 #include "memory/genCollectedHeap.hpp"
 #include "memory/universe.hpp"
 #include "oops/objArrayKlass.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/jniHandles.hpp"
 #include "runtime/reflectionUtils.hpp"
 #include "runtime/vframe.hpp"
 #include "runtime/vmThread.hpp"
 #include "runtime/vm_operations.hpp"
 #include "services/heapDumper.hpp"
 #include "services/threadService.hpp"
 #include "utilities/ostream.hpp"
 #include "utilities/macros.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
 #endif // INCLUDE_ALL_GCS
 /*
  * HPROF binary format - description copied from:
  *   src/share/demo/jvmti/hprof/hprof_io.c
  *
  *
  *  header    "JAVA PROFILE 1.0.1" or "JAVA PROFILE 1.0.2"
  *            (0-terminated)
  *
  *  u4        size of identifiers. Identifiers are used to represent
  *            UTF8 strings, objects, stack traces, etc. They usually
  *            have the same size as host pointers. For example, on
  *            Solaris and Win32, the size is 4.
  * u4         high word
  * u4         low word    number of milliseconds since 0:00 GMT, 1/1/70
  * [record]*  a sequence of records.
  *
  *
  * Record format:
  *
  * u1         a TAG denoting the type of the record
  * u4         number of *microseconds* since the time stamp in the
  *            header. (wraps around in a little more than an hour)
  * u4         number of bytes *remaining* in the record. Note that
  *            this number excludes the tag and the length field itself.
  * [u1]*      BODY of the record (a sequence of bytes)
  *
  *
  * The following TAGs are supported:
  *
  * TAG           BODY       notes
  *----------------------------------------------------------
  * HPROF_UTF8               a UTF8-encoded name
  *
  *               id         name ID
  *               [u1]*      UTF8 characters (no trailing zero)
  *
  * HPROF_LOAD_CLASS         a newly loaded class
  *
  *                u4        class serial number (> 0)
  *                id        class object ID
  *                u4        stack trace serial number
  *                id        class name ID
  *
  * HPROF_UNLOAD_CLASS       an unloading class
  *
  *                u4        class serial_number
  *
  * HPROF_FRAME              a Java stack frame
  *
  *                id        stack frame ID
  *                id        method name ID
  *                id        method signature ID
  *                id        source file name ID
  *                u4        class serial number
  *                i4        line number. >0: normal
  *                                       -1: unknown
  *                                       -2: compiled method
  *                                       -3: native method
  *
  * HPROF_TRACE              a Java stack trace
  *
  *               u4         stack trace serial number
  *               u4         thread serial number
  *               u4         number of frames
  *               [id]*      stack frame IDs
  *
  *
  * HPROF_ALLOC_SITES        a set of heap allocation sites, obtained after GC
  *
  *               u2         flags 0x0001: incremental vs. complete
  *                                0x0002: sorted by allocation vs. live
  *                                0x0004: whether to force a GC
  *               u4         cutoff ratio
  *               u4         total live bytes
  *               u4         total live instances
  *               u8         total bytes allocated
  *               u8         total instances allocated
  *               u4         number of sites that follow
  *               [u1        is_array: 0:  normal object
  *                                    2:  object array
  *                                    4:  boolean array
  *                                    5:  char array
  *                                    6:  float array
  *                                    7:  double array
  *                                    8:  byte array
  *                                    9:  short array
  *                                    10: int array
  *                                    11: long array
  *                u4        class serial number (may be zero during startup)
  *                u4        stack trace serial number
  *                u4        number of bytes alive
  *                u4        number of instances alive
  *                u4        number of bytes allocated
  *                u4]*      number of instance allocated
  *
  * HPROF_START_THREAD       a newly started thread.
  *
  *               u4         thread serial number (> 0)
  *               id         thread object ID
  *               u4         stack trace serial number
  *               id         thread name ID
  *               id         thread group name ID
  *               id         thread group parent name ID
  *
  * HPROF_END_THREAD         a terminating thread.
  *
  *               u4         thread serial number
  *
  * HPROF_HEAP_SUMMARY       heap summary
  *
  *               u4         total live bytes
  *               u4         total live instances
  *               u8         total bytes allocated
  *               u8         total instances allocated
  *
  * HPROF_HEAP_DUMP          denote a heap dump
  *
  *               [heap dump sub-records]*
  *
  *                          There are four kinds of heap dump sub-records:
  *
  *               u1         sub-record type
  *
  *               HPROF_GC_ROOT_UNKNOWN         unknown root
  *
  *                          id         object ID
  *
  *               HPROF_GC_ROOT_THREAD_OBJ      thread object
  *
  *                          id         thread object ID  (may be 0 for a
  *                                     thread newly attached through JNI)
  *                          u4         thread sequence number
  *                          u4         stack trace sequence number
  *
  *               HPROF_GC_ROOT_JNI_GLOBAL      JNI global ref root
  *
  *                          id         object ID
  *                          id         JNI global ref ID
  *
  *               HPROF_GC_ROOT_JNI_LOCAL       JNI local ref
  *
  *                          id         object ID
  *                          u4         thread serial number
  *                          u4         frame # in stack trace (-1 for empty)
  *
  *               HPROF_GC_ROOT_JAVA_FRAME      Java stack frame
  *
  *                          id         object ID
  *                          u4         thread serial number
  *                          u4         frame # in stack trace (-1 for empty)
  *
  *               HPROF_GC_ROOT_NATIVE_STACK    Native stack
  *
  *                          id         object ID
  *                          u4         thread serial number
  *
  *               HPROF_GC_ROOT_STICKY_CLASS    System class
  *
  *                          id         object ID
  *
  *               HPROF_GC_ROOT_THREAD_BLOCK    Reference from thread block
  *
  *                          id         object ID
  *                          u4         thread serial number
  *
  *               HPROF_GC_ROOT_MONITOR_USED    Busy monitor
  *
  *                          id         object ID
  *
  *               HPROF_GC_CLASS_DUMP           dump of a class object
  *
  *                          id         class object ID
  *                          u4         stack trace serial number
  *                          id         super class object ID
  *                          id         class loader object ID
  *                          id         signers object ID
  *                          id         protection domain object ID
  *                          id         reserved
  *                          id         reserved
  *
  *                          u4         instance size (in bytes)
  *
  *                          u2         size of constant pool
  *                          [u2,       constant pool index,
  *                           ty,       type
  *                                     2:  object
  *                                     4:  boolean
  *                                     5:  char
  *                                     6:  float
  *                                     7:  double
  *                                     8:  byte
  *                                     9:  short
  *                                     10: int
  *                                     11: long
  *                           vl]*      and value
  *
  *                          u2         number of static fields
  *                          [id,       static field name,
  *                           ty,       type,
  *                           vl]*      and value
  *
  *                          u2         number of inst. fields (not inc. super)
  *                          [id,       instance field name,
  *                           ty]*      type
  *
  *               HPROF_GC_INSTANCE_DUMP        dump of a normal object
  *
  *                          id         object ID
  *                          u4         stack trace serial number
  *                          id         class object ID
  *                          u4         number of bytes that follow
  *                          [vl]*      instance field values (class, followed
  *                                     by super, super's super ...)
  *
  *               HPROF_GC_OBJ_ARRAY_DUMP       dump of an object array
  *
  *                          id         array object ID
  *                          u4         stack trace serial number
  *                          u4         number of elements
  *                          id         array class ID
  *                          [id]*      elements
  *
  *               HPROF_GC_PRIM_ARRAY_DUMP      dump of a primitive array
  *
  *                          id         array object ID
  *                          u4         stack trace serial number
  *                          u4         number of elements
  *                          u1         element type
  *                                     4:  boolean array
  *                                     5:  char array
  *                                     6:  float array
  *                                     7:  double array
  *                                     8:  byte array
  *                                     9:  short array
  *                                     10: int array
  *                                     11: long array
  *                          [u1]*      elements
  *
  * HPROF_CPU_SAMPLES        a set of sample traces of running threads
  *
  *                u4        total number of samples
  *                u4        # of traces
  *               [u4        # of samples
  *                u4]*      stack trace serial number
  *
  * HPROF_CONTROL_SETTINGS   the settings of on/off switches
  *
  *                u4        0x00000001: alloc traces on/off
  *                          0x00000002: cpu sampling on/off
  *                u2        stack trace depth
  *
  *
  * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
  * be generated as a sequence of heap dump segments. This sequence is
  * terminated by an end record. The additional tags allowed by format
  * "JAVA PROFILE 1.0.2" are:
  *
  * HPROF_HEAP_DUMP_SEGMENT  denote a heap dump segment
  *
  *               [heap dump sub-records]*
  *               The same sub-record types allowed by HPROF_HEAP_DUMP
  *
  * HPROF_HEAP_DUMP_END      denotes the end of a heap dump
  *
  */
 // HPROF tags
 typedef enum {
   // top-level records
   HPROF_UTF8                    = 0x01,
   HPROF_LOAD_CLASS              = 0x02,
   HPROF_UNLOAD_CLASS            = 0x03,
   HPROF_FRAME                   = 0x04,
   HPROF_TRACE                   = 0x05,
   HPROF_ALLOC_SITES             = 0x06,
   HPROF_HEAP_SUMMARY            = 0x07,
   HPROF_START_THREAD            = 0x0A,
   HPROF_END_THREAD              = 0x0B,
   HPROF_HEAP_DUMP               = 0x0C,
   HPROF_CPU_SAMPLES             = 0x0D,
   HPROF_CONTROL_SETTINGS        = 0x0E,
   // 1.0.2 record types
   HPROF_HEAP_DUMP_SEGMENT       = 0x1C,
   HPROF_HEAP_DUMP_END           = 0x2C,
   // field types
   HPROF_ARRAY_OBJECT            = 0x01,
   HPROF_NORMAL_OBJECT           = 0x02,
   HPROF_BOOLEAN                 = 0x04,
   HPROF_CHAR                    = 0x05,
   HPROF_FLOAT                   = 0x06,
   HPROF_DOUBLE                  = 0x07,
   HPROF_BYTE                    = 0x08,
   HPROF_SHORT                   = 0x09,
   HPROF_INT                     = 0x0A,
   HPROF_LONG                    = 0x0B,
   // data-dump sub-records
   HPROF_GC_ROOT_UNKNOWN         = 0xFF,
   HPROF_GC_ROOT_JNI_GLOBAL      = 0x01,
   HPROF_GC_ROOT_JNI_LOCAL       = 0x02,
   HPROF_GC_ROOT_JAVA_FRAME      = 0x03,
   HPROF_GC_ROOT_NATIVE_STACK    = 0x04,
   HPROF_GC_ROOT_STICKY_CLASS    = 0x05,
   HPROF_GC_ROOT_THREAD_BLOCK    = 0x06,
   HPROF_GC_ROOT_MONITOR_USED    = 0x07,
   HPROF_GC_ROOT_THREAD_OBJ      = 0x08,
   HPROF_GC_CLASS_DUMP           = 0x20,
   HPROF_GC_INSTANCE_DUMP        = 0x21,
   HPROF_GC_OBJ_ARRAY_DUMP       = 0x22,
   HPROF_GC_PRIM_ARRAY_DUMP      = 0x23
 } hprofTag;
 // Default stack trace ID (used for dummy HPROF_TRACE record)
 enum {
   STACK_TRACE_ID = 1,
   INITIAL_CLASS_COUNT = 200
 };
 // Supports I/O operations on a dump file
 class DumpWriter : public StackObj {
  private:
   enum {
     io_buffer_size  = 8*M
   };
   int _fd;              // file descriptor (-1 if dump file not open)
   julong _bytes_written; // number of byte written to dump file
   char* _buffer;    // internal buffer
   size_t _size;
   size_t _pos;
   char* _error;   // error message when I/O fails
   void set_file_descriptor(int fd)              { _fd = fd; }
   int file_descriptor() const                   { return _fd; }
   char* buffer() const                          { return _buffer; }
   size_t buffer_size() const                    { return _size; }
   size_t position() const                       { return _pos; }
   void set_position(size_t pos)                 { _pos = pos; }
   void set_error(const char* error)             { _error = (char*)os::strdup(error); }
   // all I/O go through this function
   void write_internal(void* s, size_t len);
  public:
   DumpWriter(const char* path);
   ~DumpWriter();
   void close();
   bool is_open() const                  { return file_descriptor() >= 0; }
   void flush();
   // total number of bytes written to the disk
   julong bytes_written() const          { return _bytes_written; }
   // adjust the number of bytes written to disk (used to keep the count
   // of the number of bytes written in case of rewrites)
   void adjust_bytes_written(jlong n)    { _bytes_written += n; }
   // number of (buffered) bytes as yet unwritten to the dump file
   size_t bytes_unwritten() const        { return position(); }
   char* error() const                   { return _error; }
   jlong current_offset();
   void seek_to_offset(jlong pos);
   // writer functions
   void write_raw(void* s, size_t len);
   void write_u1(u1 x)                   { write_raw((void*)&x, 1); }
   void write_u2(u2 x);
   void write_u4(u4 x);
   void write_u8(u8 x);
   void write_objectID(oop o);
   void write_symbolID(Symbol* o);
   void write_classID(Klass* k);
   void write_id(u4 x);
 };
 DumpWriter::DumpWriter(const char* path) {
   // try to allocate an I/O buffer of io_buffer_size. If there isn't
   // sufficient memory then reduce size until we can allocate something.
   _size = io_buffer_size;
   do {
     _buffer = (char*)os::malloc(_size, mtInternal);
     if (_buffer == NULL) {
       _size = _size >> 1;
     }
   } while (_buffer == NULL && _size > 0);
   assert((_size > 0 && _buffer != NULL) || (_size == 0 && _buffer == NULL), "sanity check");
   _pos = 0;
   _error = NULL;
   _bytes_written = 0L;
   _fd = os::create_binary_file(path, false);    // don't replace existing file
   // if the open failed we record the error
   if (_fd < 0) {
     _error = (char*)os::strdup(strerror(errno));
   }
 }
 DumpWriter::~DumpWriter() {
   // flush and close dump file
   if (is_open()) {
     close();
   }
   if (_buffer != NULL) os::free(_buffer);
   if (_error != NULL) os::free(_error);
 }
 // closes dump file (if open)
 void DumpWriter::close() {
   // flush and close dump file
   if (is_open()) {
     flush();
     ::close(file_descriptor());
     set_file_descriptor(-1);
   }
 }
 // write directly to the file
 void DumpWriter::write_internal(void* s, size_t len) {
   if (is_open()) {
     const char* pos = (char*)s;
     ssize_t n = 0;
     while (len > 0) {
       uint tmp = (uint)MIN2(len, (size_t)UINT_MAX);
       n = ::write(file_descriptor(), pos, tmp);
       if (n < 0) {
         set_error(strerror(errno));
         ::close(file_descriptor());
         set_file_descriptor(-1);
         return;
       }
       _bytes_written += n;
       pos += n;
       len -= n;
     }
   }
 }
 // write raw bytes
 void DumpWriter::write_raw(void* s, size_t len) {
   if (is_open()) {
     // flush buffer to make room
     if ((position() + len) >= buffer_size()) {
       flush();
     }
     // buffer not available or too big to buffer it
     if ((buffer() == NULL) || (len >= buffer_size())) {
       write_internal(s, len);
     } else {
       // Should optimize this for u1/u2/u4/u8 sizes.
       memcpy(buffer() + position(), s, len);
       set_position(position() + len);
     }
   }
 }
 // flush any buffered bytes to the file
 void DumpWriter::flush() {
   if (is_open() && position() > 0) {
     write_internal(buffer(), position());
     set_position(0);
   }
 }
 jlong DumpWriter::current_offset() {
   if (is_open()) {
     // the offset is the file offset plus whatever we have buffered
     jlong offset = os::current_file_offset(file_descriptor());
     assert(offset >= 0, "lseek failed");
     return offset + position();
   } else {
     return (jlong)-1;
   }
 }
 void DumpWriter::seek_to_offset(jlong off) {
   assert(off >= 0, "bad offset");
   // need to flush before seeking
   flush();
   // may be closed due to I/O error
   if (is_open()) {
     jlong n = os::seek_to_file_offset(file_descriptor(), off);
     assert(n >= 0, "lseek failed");
   }
 }
 void DumpWriter::write_u2(u2 x) {
   u2 v;
   Bytes::put_Java_u2((address)&v, x);
   write_raw((void*)&v, 2);
 }
 void DumpWriter::write_u4(u4 x) {
   u4 v;
   Bytes::put_Java_u4((address)&v, x);
   write_raw((void*)&v, 4);
 }
 void DumpWriter::write_u8(u8 x) {
   u8 v;
   Bytes::put_Java_u8((address)&v, x);
   write_raw((void*)&v, 8);
 }
 void DumpWriter::write_objectID(oop o) {
   address a = (address)o;
 #ifdef _LP64
   write_u8((u8)a);
 #else
   write_u4((u4)a);
 #endif
 }
 void DumpWriter::write_symbolID(Symbol* s) {
   address a = (address)((uintptr_t)s);
 #ifdef _LP64
   write_u8((u8)a);
 #else
   write_u4((u4)a);
 #endif
 }
 void DumpWriter::write_id(u4 x) {
 #ifdef _LP64
   write_u8((u8) x);
 #else
   write_u4(x);
 #endif
 }
 // We use java mirror as the class ID
 void DumpWriter::write_classID(Klass* k) {
   write_objectID(k->java_mirror());
 }
 // Support class with a collection of functions used when dumping the heap
 class DumperSupport : AllStatic {
  public:
   // write a header of the given type
   static void write_header(DumpWriter* writer, hprofTag tag, u4 len);
   // returns hprof tag for the given type signature
   static hprofTag sig2tag(Symbol* sig);
   // returns hprof tag for the given basic type
   static hprofTag type2tag(BasicType type);
   // returns the size of the instance of the given class
   static u4 instance_size(Klass* k);
   // dump a jfloat
   static void dump_float(DumpWriter* writer, jfloat f);
   // dump a jdouble
   static void dump_double(DumpWriter* writer, jdouble d);
   // dumps the raw value of the given field
   static void dump_field_value(DumpWriter* writer, char type, address addr);
   // dumps static fields of the given class
   static void dump_static_fields(DumpWriter* writer, Klass* k);
   // dump the raw values of the instance fields of the given object
   static void dump_instance_fields(DumpWriter* writer, oop o);
   // dumps the definition of the instance fields for a given class
   static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k);
   // creates HPROF_GC_INSTANCE_DUMP record for the given object
   static void dump_instance(DumpWriter* writer, oop o);
   // creates HPROF_GC_CLASS_DUMP record for the given class and each of its
   // array classes
   static void dump_class_and_array_classes(DumpWriter* writer, Klass* k);
   // creates HPROF_GC_CLASS_DUMP record for a given primitive array
   // class (and each multi-dimensional array class too)
   static void dump_basic_type_array_class(DumpWriter* writer, Klass* k);
   // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
   static void dump_object_array(DumpWriter* writer, objArrayOop array);
   // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
   static void dump_prim_array(DumpWriter* writer, typeArrayOop array);
   // create HPROF_FRAME record for the given method and bci
   static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
 };
 // write a header of the given type
 void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) {
   writer->write_u1((u1)tag);
   writer->write_u4(0);                  // current ticks
   writer->write_u4(len);
 }
 // returns hprof tag for the given type signature
 hprofTag DumperSupport::sig2tag(Symbol* sig) {
   switch (sig->byte_at(0)) {
     case JVM_SIGNATURE_CLASS    : return HPROF_NORMAL_OBJECT;
     case JVM_SIGNATURE_ARRAY    : return HPROF_NORMAL_OBJECT;
     case JVM_SIGNATURE_BYTE     : return HPROF_BYTE;
     case JVM_SIGNATURE_CHAR     : return HPROF_CHAR;
     case JVM_SIGNATURE_FLOAT    : return HPROF_FLOAT;
     case JVM_SIGNATURE_DOUBLE   : return HPROF_DOUBLE;
     case JVM_SIGNATURE_INT      : return HPROF_INT;
     case JVM_SIGNATURE_LONG     : return HPROF_LONG;
     case JVM_SIGNATURE_SHORT    : return HPROF_SHORT;
     case JVM_SIGNATURE_BOOLEAN  : return HPROF_BOOLEAN;
     default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
   }
 }
 hprofTag DumperSupport::type2tag(BasicType type) {
   switch (type) {
     case T_BYTE     : return HPROF_BYTE;
     case T_CHAR     : return HPROF_CHAR;
     case T_FLOAT    : return HPROF_FLOAT;
     case T_DOUBLE   : return HPROF_DOUBLE;
     case T_INT      : return HPROF_INT;
     case T_LONG     : return HPROF_LONG;
     case T_SHORT    : return HPROF_SHORT;
     case T_BOOLEAN  : return HPROF_BOOLEAN;
     default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE;
   }
 }
 // dump a jfloat
 void DumperSupport::dump_float(DumpWriter* writer, jfloat f) {
   if (g_isnan(f)) {
     writer->write_u4(0x7fc00000);    // collapsing NaNs
   } else {
     union {
       int i;
       float f;
     } u;
     u.f = (float)f;
     writer->write_u4((u4)u.i);
   }
 }
 // dump a jdouble
 void DumperSupport::dump_double(DumpWriter* writer, jdouble d) {
   union {
     jlong l;
     double d;
   } u;
   if (g_isnan(d)) {                 // collapsing NaNs
     u.l = (jlong)(0x7ff80000);
     u.l = (u.l << 32);
   } else {
     u.d = (double)d;
   }
   writer->write_u8((u8)u.l);
 }
 // dumps the raw value of the given field
 void DumperSupport::dump_field_value(DumpWriter* writer, char type, address addr) {
   switch (type) {
     case JVM_SIGNATURE_CLASS :
     case JVM_SIGNATURE_ARRAY : {
       oop o;
       if (UseCompressedOops) {
         o = oopDesc::load_decode_heap_oop((narrowOop*)addr);
       } else {
         o = oopDesc::load_decode_heap_oop((oop*)addr);
       }
       // reflection and sun.misc.Unsafe classes may have a reference to a
       // Klass* so filter it out.
       assert(o->is_oop_or_null(), "should always be an oop");
       writer->write_objectID(o);
       break;
     }
     case JVM_SIGNATURE_BYTE     : {
       jbyte* b = (jbyte*)addr;
       writer->write_u1((u1)*b);
       break;
     }
     case JVM_SIGNATURE_CHAR     : {
       jchar* c = (jchar*)addr;
       writer->write_u2((u2)*c);
       break;
     }
     case JVM_SIGNATURE_SHORT : {
       jshort* s = (jshort*)addr;
       writer->write_u2((u2)*s);
       break;
     }
     case JVM_SIGNATURE_FLOAT : {
       jfloat* f = (jfloat*)addr;
       dump_float(writer, *f);
       break;
     }
     case JVM_SIGNATURE_DOUBLE : {
       jdouble* f = (jdouble*)addr;
       dump_double(writer, *f);
       break;
     }
     case JVM_SIGNATURE_INT : {
       jint* i = (jint*)addr;
       writer->write_u4((u4)*i);
       break;
     }
     case JVM_SIGNATURE_LONG     : {
       jlong* l = (jlong*)addr;
       writer->write_u8((u8)*l);
       break;
     }
     case JVM_SIGNATURE_BOOLEAN : {
       jboolean* b = (jboolean*)addr;
       writer->write_u1((u1)*b);
       break;
     }
     default : ShouldNotReachHere();
   }
 }
 // returns the size of the instance of the given class
 u4 DumperSupport::instance_size(Klass* k) {
   HandleMark hm;
   instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
   u4 size = 0;
   for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
     if (!fld.access_flags().is_static()) {
       Symbol* sig = fld.signature();
       switch (sig->byte_at(0)) {
         case JVM_SIGNATURE_CLASS   :
         case JVM_SIGNATURE_ARRAY   : size += oopSize; break;
         case JVM_SIGNATURE_BYTE    :
         case JVM_SIGNATURE_BOOLEAN : size += 1; break;
         case JVM_SIGNATURE_CHAR    :
         case JVM_SIGNATURE_SHORT   : size += 2; break;
         case JVM_SIGNATURE_INT     :
         case JVM_SIGNATURE_FLOAT   : size += 4; break;
         case JVM_SIGNATURE_LONG    :
         case JVM_SIGNATURE_DOUBLE  : size += 8; break;
         default : ShouldNotReachHere();
       }
     }
   }
   return size;
 }
 // dumps static fields of the given class
 void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) {
   HandleMark hm;
   instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
   // pass 1 - count the static fields
   u2 field_count = 0;
   for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
     if (fldc.access_flags().is_static()) field_count++;
   }
   writer->write_u2(field_count);
   // pass 2 - dump the field descriptors and raw values
   for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
     if (fld.access_flags().is_static()) {
       Symbol* sig = fld.signature();
       writer->write_symbolID(fld.name());   // name
       writer->write_u1(sig2tag(sig));       // type
       // value
       int offset = fld.offset();
       address addr = (address)ikh->java_mirror() + offset;
       dump_field_value(writer, sig->byte_at(0), addr);
     }
   }
 }
 // dump the raw values of the instance fields of the given object
 void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) {
   HandleMark hm;
   instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), o->klass());
   for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
     if (!fld.access_flags().is_static()) {
       Symbol* sig = fld.signature();
       address addr = (address)o + fld.offset();
       dump_field_value(writer, sig->byte_at(0), addr);
     }
   }
 }
 // dumps the definition of the instance fields for a given class
 void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) {
   HandleMark hm;
   instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
   // pass 1 - count the instance fields
   u2 field_count = 0;
   for (FieldStream fldc(ikh, true, true); !fldc.eos(); fldc.next()) {
     if (!fldc.access_flags().is_static()) field_count++;
   }
   writer->write_u2(field_count);
   // pass 2 - dump the field descriptors
   for (FieldStream fld(ikh, true, true); !fld.eos(); fld.next()) {
     if (!fld.access_flags().is_static()) {
       Symbol* sig = fld.signature();
       writer->write_symbolID(fld.name());                   // name
       writer->write_u1(sig2tag(sig));       // type
     }
   }
 }
 // creates HPROF_GC_INSTANCE_DUMP record for the given object
 void DumperSupport::dump_instance(DumpWriter* writer, oop o) {
   Klass* k = o->klass();
   writer->write_u1(HPROF_GC_INSTANCE_DUMP);
   writer->write_objectID(o);
   writer->write_u4(STACK_TRACE_ID);
   // class ID
   writer->write_classID(k);
   // number of bytes that follow
   writer->write_u4(instance_size(k) );
   // field values
   dump_instance_fields(writer, o);
 }
 // creates HPROF_GC_CLASS_DUMP record for the given class and each of
 // its array classes
 void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) {
   Klass* klass = k;
   assert(klass->oop_is_instance(), "not an InstanceKlass");
   InstanceKlass* ik = (InstanceKlass*)klass;
   writer->write_u1(HPROF_GC_CLASS_DUMP);
   // class ID
   writer->write_classID(ik);
   writer->write_u4(STACK_TRACE_ID);
   // super class ID
   Klass* java_super = ik->java_super();
   if (java_super == NULL) {
     writer->write_objectID(oop(NULL));
   } else {
     writer->write_classID(java_super);
   }
   writer->write_objectID(ik->class_loader());
   writer->write_objectID(ik->signers());
   writer->write_objectID(ik->protection_domain());
   // reserved
   writer->write_objectID(oop(NULL));
   writer->write_objectID(oop(NULL));
   // instance size
   writer->write_u4(DumperSupport::instance_size(k));
   // size of constant pool - ignored by HAT 1.1
   writer->write_u2(0);
   // number of static fields
   dump_static_fields(writer, k);
   // description of instance fields
   dump_instance_field_descriptors(writer, k);
   // array classes
   k = klass->array_klass_or_null();
   while (k != NULL) {
     Klass* klass = k;
     assert(klass->oop_is_objArray(), "not an ObjArrayKlass");
     writer->write_u1(HPROF_GC_CLASS_DUMP);
     writer->write_classID(klass);
     writer->write_u4(STACK_TRACE_ID);
     // super class of array classes is java.lang.Object
     java_super = klass->java_super();
     assert(java_super != NULL, "checking");
     writer->write_classID(java_super);
     writer->write_objectID(ik->class_loader());
     writer->write_objectID(ik->signers());
     writer->write_objectID(ik->protection_domain());
     writer->write_objectID(oop(NULL));    // reserved
     writer->write_objectID(oop(NULL));
     writer->write_u4(0);             // instance size
     writer->write_u2(0);             // constant pool
     writer->write_u2(0);             // static fields
     writer->write_u2(0);             // instance fields
     // get the array class for the next rank
     k = klass->array_klass_or_null();
   }
 }
 // creates HPROF_GC_CLASS_DUMP record for a given primitive array
 // class (and each multi-dimensional array class too)
 void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) {
  // array classes
  while (k != NULL) {
     Klass* klass = k;
     writer->write_u1(HPROF_GC_CLASS_DUMP);
     writer->write_classID(klass);
     writer->write_u4(STACK_TRACE_ID);
     // super class of array classes is java.lang.Object
     Klass* java_super = klass->java_super();
     assert(java_super != NULL, "checking");
     writer->write_classID(java_super);
     writer->write_objectID(oop(NULL));    // loader
     writer->write_objectID(oop(NULL));    // signers
     writer->write_objectID(oop(NULL));    // protection domain
     writer->write_objectID(oop(NULL));    // reserved
     writer->write_objectID(oop(NULL));
     writer->write_u4(0);             // instance size
     writer->write_u2(0);             // constant pool
     writer->write_u2(0);             // static fields
     writer->write_u2(0);             // instance fields
     // get the array class for the next rank
     k = klass->array_klass_or_null();
   }
 }
 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
 void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) {
   writer->write_u1(HPROF_GC_OBJ_ARRAY_DUMP);
   writer->write_objectID(array);
   writer->write_u4(STACK_TRACE_ID);
   writer->write_u4((u4)array->length());
   // array class ID
   writer->write_classID(array->klass());
   // [id]* elements
   for (int index=0; index<array->length(); index++) {
     oop o = array->obj_at(index);
     writer->write_objectID(o);
   }
 }
 #define WRITE_ARRAY(Array, Type, Size) \
   for (int i=0; i<Array->length(); i++) { writer->write_##Size((Size)array->Type##_at(i)); }
 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
 void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) {
   BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
   writer->write_u1(HPROF_GC_PRIM_ARRAY_DUMP);
   writer->write_objectID(array);
   writer->write_u4(STACK_TRACE_ID);
   writer->write_u4((u4)array->length());
   writer->write_u1(type2tag(type));
   // nothing to copy
   if (array->length() == 0) {
     return;
   }
   // If the byte ordering is big endian then we can copy most types directly
   u4 length_in_bytes = (u4)array->length() * type2aelembytes(type);
   switch (type) {
     case T_INT : {
       if (Bytes::is_Java_byte_ordering_different()) {
         WRITE_ARRAY(array, int, u4);
       } else {
         writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes);
       }
       break;
     }
     case T_BYTE : {
       writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes);
       break;
     }
     case T_CHAR : {
       if (Bytes::is_Java_byte_ordering_different()) {
         WRITE_ARRAY(array, char, u2);
       } else {
         writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes);
       }
       break;
     }
     case T_SHORT : {
       if (Bytes::is_Java_byte_ordering_different()) {
         WRITE_ARRAY(array, short, u2);
       } else {
         writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes);
       }
       break;
     }
     case T_BOOLEAN : {
       if (Bytes::is_Java_byte_ordering_different()) {
         WRITE_ARRAY(array, bool, u1);
       } else {
         writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes);
       }
       break;
     }
     case T_LONG : {
       if (Bytes::is_Java_byte_ordering_different()) {
         WRITE_ARRAY(array, long, u8);
       } else {
         writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes);
       }
       break;
     }
     // handle float/doubles in a special value to ensure than NaNs are
     // written correctly. TO DO: Check if we can avoid this on processors that
     // use IEEE 754.
     case T_FLOAT : {
       for (int i=0; i<array->length(); i++) {
         dump_float( writer, array->float_at(i) );
       }
       break;
     }
     case T_DOUBLE : {
       for (int i=0; i<array->length(); i++) {
         dump_double( writer, array->double_at(i) );
       }
       break;
     }
     default : ShouldNotReachHere();
   }
 }
 // create a HPROF_FRAME record of the given Method* and bci
 void DumperSupport::dump_stack_frame(DumpWriter* writer,
                                      int frame_serial_num,
                                      int class_serial_num,
                                      Method* m,
                                      int bci) {
   int line_number;
   if (m->is_native()) {
     line_number = -3;  // native frame
   } else {
     line_number = m->line_number_from_bci(bci);
   }
   write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
   writer->write_id(frame_serial_num);               // frame serial number
   writer->write_symbolID(m->name());                // method's name
   writer->write_symbolID(m->signature());           // method's signature
   assert(m->method_holder()->oop_is_instance(), "not InstanceKlass");
   writer->write_symbolID(m->method_holder()->source_file_name());  // source file name
   writer->write_u4(class_serial_num);               // class serial number
   writer->write_u4((u4) line_number);               // line number
 }
 // Support class used to generate HPROF_UTF8 records from the entries in the
 // SymbolTable.
 class SymbolTableDumper : public SymbolClosure {
  private:
   DumpWriter* _writer;
   DumpWriter* writer() const                { return _writer; }
  public:
   SymbolTableDumper(DumpWriter* writer)     { _writer = writer; }
   void do_symbol(Symbol** p);
 };
 void SymbolTableDumper::do_symbol(Symbol** p) {
   ResourceMark rm;
   Symbol* sym = load_symbol(p);
   int len = sym->utf8_length();
   if (len > 0) {
     char* s = sym->as_utf8();
     DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
     writer()->write_symbolID(sym);
     writer()->write_raw(s, len);
   }
 }
 // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records
 class JNILocalsDumper : public OopClosure {
  private:
   DumpWriter* _writer;
   u4 _thread_serial_num;
   int _frame_num;
   DumpWriter* writer() const                { return _writer; }
  public:
   JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
     _writer = writer;
     _thread_serial_num = thread_serial_num;
     _frame_num = -1;  // default - empty stack
   }
   void set_frame_number(int n) { _frame_num = n; }
   void do_oop(oop* obj_p);
   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
 };
 void JNILocalsDumper::do_oop(oop* obj_p) {
   // ignore null or deleted handles
   oop o = *obj_p;
   if (o != NULL && o != JNIHandles::deleted_handle()) {
     writer()->write_u1(HPROF_GC_ROOT_JNI_LOCAL);
     writer()->write_objectID(o);
     writer()->write_u4(_thread_serial_num);
     writer()->write_u4((u4)_frame_num);
   }
 }
 // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records
 class JNIGlobalsDumper : public OopClosure {
  private:
   DumpWriter* _writer;
   DumpWriter* writer() const                { return _writer; }
  public:
   JNIGlobalsDumper(DumpWriter* writer) {
     _writer = writer;
   }
   void do_oop(oop* obj_p);
   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
 };
 void JNIGlobalsDumper::do_oop(oop* obj_p) {
   oop o = *obj_p;
   // ignore these
   if (o == NULL || o == JNIHandles::deleted_handle()) return;
   // we ignore global ref to symbols and other internal objects
   if (o->is_instance() || o->is_objArray() || o->is_typeArray()) {
     writer()->write_u1(HPROF_GC_ROOT_JNI_GLOBAL);
     writer()->write_objectID(o);
     writer()->write_objectID((oopDesc*)obj_p);      // global ref ID
   }
 };
 // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records
 class MonitorUsedDumper : public OopClosure {
  private:
   DumpWriter* _writer;
   DumpWriter* writer() const                { return _writer; }
  public:
   MonitorUsedDumper(DumpWriter* writer) {
     _writer = writer;
   }
   void do_oop(oop* obj_p) {
     writer()->write_u1(HPROF_GC_ROOT_MONITOR_USED);
     writer()->write_objectID(*obj_p);
   }
   void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
 };
 // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
 class StickyClassDumper : public KlassClosure {
  private:
   DumpWriter* _writer;
   DumpWriter* writer() const                { return _writer; }
  public:
   StickyClassDumper(DumpWriter* writer) {
     _writer = writer;
   }
   void do_klass(Klass* k) {
     if (k->oop_is_instance()) {
       InstanceKlass* ik = InstanceKlass::cast(k);
         writer()->write_u1(HPROF_GC_ROOT_STICKY_CLASS);
         writer()->write_classID(ik);
       }
     }
 };
 class VM_HeapDumper;
 // Support class using when iterating over the heap.
 class HeapObjectDumper : public ObjectClosure {
  private:
   VM_HeapDumper* _dumper;
   DumpWriter* _writer;
   VM_HeapDumper* dumper()               { return _dumper; }
   DumpWriter* writer()                  { return _writer; }
   // used to indicate that a record has been writen
   void mark_end_of_record();
  public:
   HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) {
     _dumper = dumper;
     _writer = writer;
   }
   // called for each object in the heap
   void do_object(oop o);
 };
 void HeapObjectDumper::do_object(oop o) {
   // hide the sentinel for deleted handles
   if (o == JNIHandles::deleted_handle()) return;
   // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
   if (o->klass() == SystemDictionary::Class_klass()) {
     if (!java_lang_Class::is_primitive(o)) {
       return;
     }
   }
   if (o->is_instance()) {
     // create a HPROF_GC_INSTANCE record for each object
     DumperSupport::dump_instance(writer(), o);
     mark_end_of_record();
   } else if (o->is_objArray()) {
     // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
     DumperSupport::dump_object_array(writer(), objArrayOop(o));
     mark_end_of_record();
   } else if (o->is_typeArray()) {
     // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
     DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
     mark_end_of_record();
   }
 }
 // The VM operation that performs the heap dump
 class VM_HeapDumper : public VM_GC_Operation {
  private:
   static VM_HeapDumper* _global_dumper;
   static DumpWriter*    _global_writer;
   DumpWriter*           _local_writer;
   JavaThread*           _oome_thread;
   Method*               _oome_constructor;
   bool _gc_before_heap_dump;
   bool _is_segmented_dump;
   jlong _dump_start;
   GrowableArray<Klass*>* _klass_map;
   ThreadStackTrace** _stack_traces;
   int _num_threads;
   // accessors and setters
   static VM_HeapDumper* dumper()         {  assert(_global_dumper != NULL, "Error"); return _global_dumper; }
   static DumpWriter* writer()            {  assert(_global_writer != NULL, "Error"); return _global_writer; }
   void set_global_dumper() {
     assert(_global_dumper == NULL, "Error");
     _global_dumper = this;
   }
   void set_global_writer() {
     assert(_global_writer == NULL, "Error");
     _global_writer = _local_writer;
   }
   void clear_global_dumper() { _global_dumper = NULL; }
   void clear_global_writer() { _global_writer = NULL; }
   bool is_segmented_dump() const                { return _is_segmented_dump; }
   void set_segmented_dump()                     { _is_segmented_dump = true; }
   jlong dump_start() const                      { return _dump_start; }
   void set_dump_start(jlong pos);
   bool skip_operation() const;
   // writes a HPROF_LOAD_CLASS record
   static void do_load_class(Klass* k);
   // writes a HPROF_GC_CLASS_DUMP record for the given class
   // (and each array class too)
   static void do_class_dump(Klass* k);
   // writes a HPROF_GC_CLASS_DUMP records for a given basic type
   // array (and each multi-dimensional array too)
   static void do_basic_type_array_class_dump(Klass* k);
   // HPROF_GC_ROOT_THREAD_OBJ records
   int do_thread(JavaThread* thread, u4 thread_serial_num);
   void do_threads();
   void add_class_serial_number(Klass* k, int serial_num) {
     _klass_map->at_put_grow(serial_num, k);
   }
   // HPROF_TRACE and HPROF_FRAME records
   void dump_stack_traces();
   // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
   void write_dump_header();
   // fixes up the length of the current dump record
   void write_current_dump_record_length();
   // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
   // record in the case of a segmented heap dump)
   void end_of_dump();
  public:
   VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) :
     VM_GC_Operation(0 /* total collections,      dummy, ignored */,
                     GCCause::_heap_dump /* GC Cause */,
 /* total full collections, dummy, ignored */,
                     gc_before_heap_dump) {
     _local_writer = writer;
     _gc_before_heap_dump = gc_before_heap_dump;
     _is_segmented_dump = false;
     _dump_start = (jlong)-1;
     _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<Klass*>(INITIAL_CLASS_COUNT, true);
     _stack_traces = NULL;
     _num_threads = 0;
     if (oome) {
       assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread");
       // get OutOfMemoryError zero-parameter constructor
       InstanceKlass* oome_ik = InstanceKlass::cast(SystemDictionary::OutOfMemoryError_klass());
       _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(),
                                                           vmSymbols::void_method_signature());
       // get thread throwing OOME when generating the heap dump at OOME
       _oome_thread = JavaThread::current();
     } else {
       _oome_thread = NULL;
       _oome_constructor = NULL;
     }
   }
   ~VM_HeapDumper() {
     if (_stack_traces != NULL) {
       for (int i=0; i < _num_threads; i++) {
         delete _stack_traces[i];
       }
       FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces, mtInternal);
     }
     delete _klass_map;
   }
   VMOp_Type type() const { return VMOp_HeapDumper; }
   // used to mark sub-record boundary
   void check_segment_length();
   void doit();
 };
 VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL;
 DumpWriter*    VM_HeapDumper::_global_writer = NULL;
 bool VM_HeapDumper::skip_operation() const {
   return false;
 }
 // sets the dump starting position
 void VM_HeapDumper::set_dump_start(jlong pos) {
   _dump_start = pos;
 }
  // writes a HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT record
 void VM_HeapDumper::write_dump_header() {
   if (writer()->is_open()) {
     if (is_segmented_dump()) {
       writer()->write_u1(HPROF_HEAP_DUMP_SEGMENT);
     } else {
       writer()->write_u1(HPROF_HEAP_DUMP);
     }
     writer()->write_u4(0); // current ticks
     // record the starting position for the dump (its length will be fixed up later)
     set_dump_start(writer()->current_offset());
     writer()->write_u4(0);
   }
 }
 // fixes up the length of the current dump record
 void VM_HeapDumper::write_current_dump_record_length() {
   if (writer()->is_open()) {
     assert(dump_start() >= 0, "no dump start recorded");
     // calculate the size of the dump record
     julong dump_end = writer()->current_offset();
     julong dump_len = (dump_end - dump_start() - 4);
     // record length must fit in a u4
     if (dump_len > max_juint) {
       warning("record is too large");
     }
     // seek to the dump start and fix-up the length
     writer()->seek_to_offset(dump_start());
     writer()->write_u4((u4)dump_len);
     // adjust the total size written to keep the bytes written correct.
     writer()->adjust_bytes_written(-((jlong) sizeof(u4)));
     // seek to dump end so we can continue
     writer()->seek_to_offset(dump_end);
     // no current dump record
     set_dump_start((jlong)-1);
   }
 }
 // used on a sub-record boundary to check if we need to start a
 // new segment.
 void VM_HeapDumper::check_segment_length() {
   if (writer()->is_open()) {
     if (is_segmented_dump()) {
       // don't use current_offset that would be too expensive on a per record basis
       julong dump_end = writer()->bytes_written() + writer()->bytes_unwritten();
       assert(dump_end == (julong)writer()->current_offset(), "checking");
       julong dump_len = (dump_end - dump_start() - 4);
       assert(dump_len <= max_juint, "bad dump length");
       if (dump_len > HeapDumpSegmentSize) {
         write_current_dump_record_length();
         write_dump_header();
       }
     }
   }
 }
 // fixes up the current dump record )and writes HPROF_HEAP_DUMP_END
 // record in the case of a segmented heap dump)
 void VM_HeapDumper::end_of_dump() {
   if (writer()->is_open()) {
     write_current_dump_record_length();
     // for segmented dump we write the end record
     if (is_segmented_dump()) {
       writer()->write_u1(HPROF_HEAP_DUMP_END);
       writer()->write_u4(0);
       writer()->write_u4(0);
     }
   }
 }
 // marks sub-record boundary
 void HeapObjectDumper::mark_end_of_record() {
   dumper()->check_segment_length();
 }
 // writes a HPROF_LOAD_CLASS record for the class (and each of its
 // array classes)
 void VM_HeapDumper::do_load_class(Klass* k) {
   static u4 class_serial_num = 0;
   // len of HPROF_LOAD_CLASS record
   u4 remaining = 2*oopSize + 2*sizeof(u4);
   // write a HPROF_LOAD_CLASS for the class and each array class
   do {
     DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining);
     // class serial number is just a number
     writer()->write_u4(++class_serial_num);
     // class ID
     Klass* klass = k;
     writer()->write_classID(klass);
     // add the Klass* and class serial number pair
     dumper()->add_class_serial_number(klass, class_serial_num);
     writer()->write_u4(STACK_TRACE_ID);
     // class name ID
     Symbol* name = klass->name();
     writer()->write_symbolID(name);
     // write a LOAD_CLASS record for the array type (if it exists)
     k = klass->array_klass_or_null();
   } while (k != NULL);
 }
 // writes a HPROF_GC_CLASS_DUMP record for the given class
 void VM_HeapDumper::do_class_dump(Klass* k) {
   if (k->oop_is_instance()) {
     DumperSupport::dump_class_and_array_classes(writer(), k);
   }
 }
 // writes a HPROF_GC_CLASS_DUMP records for a given basic type
 // array (and each multi-dimensional array too)
 void VM_HeapDumper::do_basic_type_array_class_dump(Klass* k) {
   DumperSupport::dump_basic_type_array_class(writer(), k);
 }
 // Walk the stack of the given thread.
 // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local
 // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local
 //
 // It returns the number of Java frames in this thread stack
 int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) {
   JNILocalsDumper blk(writer(), thread_serial_num);
   oop threadObj = java_thread->threadObj();
   assert(threadObj != NULL, "sanity check");
   int stack_depth = 0;
   if (java_thread->has_last_Java_frame()) {
     // vframes are resource allocated
     Thread* current_thread = Thread::current();
     ResourceMark rm(current_thread);
     HandleMark hm(current_thread);
     RegisterMap reg_map(java_thread);
     frame f = java_thread->last_frame();
     vframe* vf = vframe::new_vframe(&f, &reg_map, java_thread);
     frame* last_entry_frame = NULL;
     int extra_frames = 0;
     if (java_thread == _oome_thread && _oome_constructor != NULL) {
       extra_frames++;
     }
     while (vf != NULL) {
       blk.set_frame_number(stack_depth);
       if (vf->is_java_frame()) {
         // java frame (interpreted, compiled, ...)
         javaVFrame *jvf = javaVFrame::cast(vf);
         if (!(jvf->method()->is_native())) {
           StackValueCollection* locals = jvf->locals();
           for (int slot=0; slot<locals->size(); slot++) {
             if (locals->at(slot)->type() == T_OBJECT) {
               oop o = locals->obj_at(slot)();
               if (o != NULL) {
                 writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME);
                 writer()->write_objectID(o);
                 writer()->write_u4(thread_serial_num);
                 writer()->write_u4((u4) (stack_depth + extra_frames));
               }
             }
           }
         } else {
           // native frame
           if (stack_depth == 0) {
             // JNI locals for the top frame.
             java_thread->active_handles()->oops_do(&blk);
           } else {
             if (last_entry_frame != NULL) {
               // JNI locals for the entry frame
               assert(last_entry_frame->is_entry_frame(), "checking");
               last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk);
             }
           }
         }
         // increment only for Java frames
         stack_depth++;
         last_entry_frame = NULL;
       } else {
         // externalVFrame - if it's an entry frame then report any JNI locals
         // as roots when we find the corresponding native javaVFrame
         frame* fr = vf->frame_pointer();
         assert(fr != NULL, "sanity check");
         if (fr->is_entry_frame()) {
           last_entry_frame = fr;
         }
       }
       vf = vf->sender();
     }
   } else {
     // no last java frame but there may be JNI locals
     java_thread->active_handles()->oops_do(&blk);
   }
   return stack_depth;
 }
 // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk
 // the stack so that locals and JNI locals are dumped.
 void VM_HeapDumper::do_threads() {
   for (int i=0; i < _num_threads; i++) {
     JavaThread* thread = _stack_traces[i]->thread();
     oop threadObj = thread->threadObj();
     u4 thread_serial_num = i+1;
     u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID;
     writer()->write_u1(HPROF_GC_ROOT_THREAD_OBJ);
     writer()->write_objectID(threadObj);
     writer()->write_u4(thread_serial_num);  // thread number
     writer()->write_u4(stack_serial_num);   // stack trace serial number
     int num_frames = do_thread(thread, thread_serial_num);
     assert(num_frames == _stack_traces[i]->get_stack_depth(),
            "total number of Java frames not matched");
   }
 }
 // The VM operation that dumps the heap. The dump consists of the following
 // records:
 //
 //  HPROF_HEADER
 //  [HPROF_UTF8]*
 //  [HPROF_LOAD_CLASS]*
 //  [[HPROF_FRAME]*|HPROF_TRACE]*
 //  [HPROF_GC_CLASS_DUMP]*
 //  HPROF_HEAP_DUMP
 //
 // The HPROF_TRACE records represent the stack traces where the heap dump
 // is generated and a "dummy trace" record which does not include
 // any frames. The dummy trace record is used to be referenced as the
 // unknown object alloc site.
 //
 // The HPROF_HEAP_DUMP record has a length following by sub-records. To allow
 // the heap dump be generated in a single pass we remember the position of
 // the dump length and fix it up after all sub-records have been written.
 // To generate the sub-records we iterate over the heap, writing
 // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP
 // records as we go. Once that is done we write records for some of the GC
 // roots.
 void VM_HeapDumper::doit() {
   HandleMark hm;
   CollectedHeap* ch = Universe::heap();
   ch->ensure_parsability(false); // must happen, even if collection does
                                  // not happen (e.g. due to GC_locker)
   if (_gc_before_heap_dump) {
     if (GC_locker::is_active()) {
       warning("GC locker is held; pre-heapdump GC was skipped");
     } else {
       ch->collect_as_vm_thread(GCCause::_heap_dump);
     }
   }
   // At this point we should be the only dumper active, so
   // the following should be safe.
   set_global_dumper();
   set_global_writer();
   // Write the file header - use 1.0.2 for large heaps, otherwise 1.0.1
   size_t used = ch->used();
   const char* header;
   if (used > (size_t)SegmentedHeapDumpThreshold) {
     set_segmented_dump();
     header = "JAVA PROFILE 1.0.2";
   } else {
     header = "JAVA PROFILE 1.0.1";
   }
   // header is few bytes long - no chance to overflow int
   writer()->write_raw((void*)header, (int)strlen(header));
   writer()->write_u1(0); // terminator
   writer()->write_u4(oopSize);
   writer()->write_u8(os::javaTimeMillis());
   // HPROF_UTF8 records
   SymbolTableDumper sym_dumper(writer());
   SymbolTable::symbols_do(&sym_dumper);
   // write HPROF_LOAD_CLASS records
   ClassLoaderDataGraph::classes_do(&do_load_class);
   Universe::basic_type_classes_do(&do_load_class);
   // write HPROF_FRAME and HPROF_TRACE records
   // this must be called after _klass_map is built when iterating the classes above.
   dump_stack_traces();
   // write HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT
   write_dump_header();
   // Writes HPROF_GC_CLASS_DUMP records
   ClassLoaderDataGraph::classes_do(&do_class_dump);
   Universe::basic_type_classes_do(&do_basic_type_array_class_dump);
   check_segment_length();
   // writes HPROF_GC_INSTANCE_DUMP records.
   // After each sub-record is written check_segment_length will be invoked. When
   // generated a segmented heap dump this allows us to check if the current
   // segment exceeds a threshold and if so, then a new segment is started.
   // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
   // of the heap dump.
   HeapObjectDumper obj_dumper(this, writer());
   Universe::heap()->safe_object_iterate(&obj_dumper);
   // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
   do_threads();
   check_segment_length();
   // HPROF_GC_ROOT_MONITOR_USED
   MonitorUsedDumper mon_dumper(writer());
   ObjectSynchronizer::oops_do(&mon_dumper);
   check_segment_length();
   // HPROF_GC_ROOT_JNI_GLOBAL
   JNIGlobalsDumper jni_dumper(writer());
   JNIHandles::oops_do(&jni_dumper);
   check_segment_length();
   // HPROF_GC_ROOT_STICKY_CLASS
   StickyClassDumper class_dumper(writer());
   SystemDictionary::always_strong_classes_do(&class_dumper);
   // fixes up the length of the dump record. In the case of a segmented
   // heap then the HPROF_HEAP_DUMP_END record is also written.
   end_of_dump();
   // Now we clear the global variables, so that a future dumper might run.
   clear_global_dumper();
   clear_global_writer();
 }
 void VM_HeapDumper::dump_stack_traces() {
   // write a HPROF_TRACE record without any frames to be referenced as object alloc sites
   DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
   writer()->write_u4((u4) STACK_TRACE_ID);
   writer()->write_u4(0);                    // thread number
   writer()->write_u4(0);                    // frame count
   _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal);
   int frame_serial_num = 0;
   for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) {
     oop threadObj = thread->threadObj();
     if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) {
       // dump thread stack trace
       ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false);
       stack_trace->dump_stack_at_safepoint(-1);
       _stack_traces[_num_threads++] = stack_trace;
       // write HPROF_FRAME records for this thread's stack trace
       int depth = stack_trace->get_stack_depth();
       int thread_frame_start = frame_serial_num;
       int extra_frames = 0;
       // write fake frame that makes it look like the thread, which caused OOME,
       // is in the OutOfMemoryError zero-parameter constructor
       if (thread == _oome_thread && _oome_constructor != NULL) {
         int oome_serial_num = _klass_map->find(_oome_constructor->method_holder());
         // the class serial number starts from 1
         assert(oome_serial_num > 0, "OutOfMemoryError class not found");
         DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num,
                                         _oome_constructor, 0);
         extra_frames++;
       }
       for (int j=0; j < depth; j++) {
         StackFrameInfo* frame = stack_trace->stack_frame_at(j);
         Method* m = frame->method();
         int class_serial_num = _klass_map->find(m->method_holder());
         // the class serial number starts from 1
         assert(class_serial_num > 0, "class not found");
         DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci());
       }
       depth += extra_frames;
       // write HPROF_TRACE record for one thread
       DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize);
       int stack_serial_num = _num_threads + STACK_TRACE_ID;
       writer()->write_u4(stack_serial_num);      // stack trace serial number
       writer()->write_u4((u4) _num_threads);     // thread serial number
       writer()->write_u4(depth);                 // frame count
       for (int j=1; j <= depth; j++) {
         writer()->write_id(thread_frame_start + j);
       }
     }
   }
 }
 // dump the heap to given path.
 PRAGMA_FORMAT_NONLITERAL_IGNORED_EXTERNAL
 int HeapDumper::dump(const char* path) {
   assert(path != NULL && strlen(path) > 0, "path missing");
   // print message in interactive case
   if (print_to_tty()) {
     tty->print_cr("Dumping heap to %s ...", path);
     timer()->start();
   }
   // create the dump writer. If the file can be opened then bail
   DumpWriter writer(path);
   if (!writer.is_open()) {
     set_error(writer.error());
     if (print_to_tty()) {
       tty->print_cr("Unable to create %s: %s", path,
         (error() != NULL) ? error() : "reason unknown");
     }
     return -1;
   }
   // generate the dump
   VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome);
   if (Thread::current()->is_VM_thread()) {
     assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint");
     dumper.doit();
   } else {
     VMThread::execute(&dumper);
   }
   // close dump file and record any error that the writer may have encountered
   writer.close();
   set_error(writer.error());
   // print message in interactive case
   if (print_to_tty()) {
     timer()->stop();
     if (error() == NULL) {
       tty->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]",
                     writer.bytes_written(), timer()->seconds());
     } else {
       tty->print_cr("Dump file is incomplete: %s", writer.error());
     }
   }
   return (writer.error() == NULL) ? 0 : -1;
 }
 // stop timer (if still active), and free any error string we might be holding
 HeapDumper::~HeapDumper() {
   if (timer()->is_active()) {
     timer()->stop();
   }
   set_error(NULL);
 }
 // returns the error string (resource allocated), or NULL
 char* HeapDumper::error_as_C_string() const {
   if (error() != NULL) {
     char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
     strcpy(str, error());
     return str;
   } else {
     return NULL;
   }
 }
 // set the error string
 void HeapDumper::set_error(char* error) {
   if (_error != NULL) {
     os::free(_error);
   }
   if (error == NULL) {
     _error = NULL;
   } else {
     _error = os::strdup(error);
     assert(_error != NULL, "allocation failure");
   }
 }
 // Called by out-of-memory error reporting by a single Java thread
 // outside of a JVM safepoint
 void HeapDumper::dump_heap_from_oome() {
   HeapDumper::dump_heap(true);
 }
 // Called by error reporting by a single Java thread outside of a JVM safepoint,
 // or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various
 // callers are strictly serialized and guaranteed not to interfere below. For more
 // general use, however, this method will need modification to prevent
 // inteference when updating the static variables base_path and dump_file_seq below.
 void HeapDumper::dump_heap() {
   HeapDumper::dump_heap(false);
 }
 void HeapDumper::dump_heap(bool oome) {
   static char base_path[JVM_MAXPATHLEN] = {'\0'};
   static uint dump_file_seq = 0;
   char* my_path;
   const int max_digit_chars = 20;
   const char* dump_file_name = "java_pid";
   const char* dump_file_ext  = ".hprof";
   // The dump file defaults to java_pid<pid>.hprof in the current working
   // directory. HeapDumpPath=<file> can be used to specify an alternative
   // dump file name or a directory where dump file is created.
   if (dump_file_seq == 0) { // first time in, we initialize base_path
     // Calculate potentially longest base path and check if we have enough
     // allocated statically.
     const size_t total_length =
                       (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) +
                       strlen(os::file_separator()) + max_digit_chars +
                       strlen(dump_file_name) + strlen(dump_file_ext) + 1;
     if (total_length > sizeof(base_path)) {
       warning("Cannot create heap dump file.  HeapDumpPath is too long.");
       return;
     }
     bool use_default_filename = true;
     if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
       // HeapDumpPath=<file> not specified
     } else {
       strncpy(base_path, HeapDumpPath, sizeof(base_path));
       // check if the path is a directory (must exist)
       DIR* dir = os::opendir(base_path);
       if (dir == NULL) {
         use_default_filename = false;
       } else {
         // HeapDumpPath specified a directory. We append a file separator
         // (if needed).
         os::closedir(dir);
         size_t fs_len = strlen(os::file_separator());
         if (strlen(base_path) >= fs_len) {
           char* end = base_path;
           end += (strlen(base_path) - fs_len);
           if (strcmp(end, os::file_separator()) != 0) {
             strcat(base_path, os::file_separator());
           }
         }
       }
     }
     // If HeapDumpPath wasn't a file name then we append the default name
     if (use_default_filename) {
       const size_t dlen = strlen(base_path);  // if heap dump dir specified
       jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s",
                    dump_file_name, os::current_process_id(), dump_file_ext);
     }
     const size_t len = strlen(base_path) + 1;
     my_path = (char*)os::malloc(len, mtInternal);
     if (my_path == NULL) {
       warning("Cannot create heap dump file.  Out of system memory.");
       return;
     }
     strncpy(my_path, base_path, len);
   } else {
     // Append a sequence number id for dumps following the first
     const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0
     my_path = (char*)os::malloc(len, mtInternal);
     if (my_path == NULL) {
       warning("Cannot create heap dump file.  Out of system memory.");
       return;
     }
     jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq);
   }
   dump_file_seq++;   // increment seq number for next time we dump
   HeapDumper dumper(false /* no GC before heap dump */,
                     true  /* send to tty */,
                     oome  /* pass along out-of-memory-error flag */);
   dumper.dump(my_path);
   os::free(my_path);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/services/heapDumper.cpp@04d83ba48607 (annotated)

src/share/vm/services/heapDumper.cpp