--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/services/heapDumper.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1773 @@
+/*
+ * Copyright 2005-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_heapDumper.cpp.incl"
+
+/*
+ * 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
+};
+
+
+// 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)
+  jlong _bytes_written; // number of byte written to dump file
+
+  char* _buffer;    // internal buffer
+  int _size;
+  int _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; }
+  int buffer_size() const                       { return _size; }
+  int position() const                          { return _pos; }
+  void set_position(int 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, int 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
+  jlong 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
+  jlong bytes_unwritten() const          { return (jlong)position(); }
+
+  char* error() const                   { return _error; }
+
+  jlong current_offset();
+  void seek_to_offset(jlong pos);
+
+  // writer functions
+  void write_raw(void* s, int 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_classID(Klass* k);
+};
+
+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);
+    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 (file_descriptor() >= 0) {
+    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 (file_descriptor() >= 0) {
+    flush();
+    ::close(file_descriptor());
+  }
+}
+
+// write directly to the file
+void DumpWriter::write_internal(void* s, int len) {
+  if (is_open()) {
+    int n = ::write(file_descriptor(), s, len);
+    if (n > 0) {
+      _bytes_written += n;
+    }
+    if (n != len) {
+      if (n < 0) {
+        set_error(strerror(errno));
+      } else {
+        set_error("file size limit");
+      }
+      ::close(file_descriptor());
+      set_file_descriptor(-1);
+    }
+  }
+}
+
+// write raw bytes
+void DumpWriter::write_raw(void* s, int len) {
+  if (is_open()) {
+    // flush buffer to make toom
+    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 + (jlong)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)((uintptr_t)o);
+#ifdef _LP64
+  write_u8((u8)a);
+#else
+  write_u4((u4)a);
+#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(symbolOop 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(klassOop 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, klassOop 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, klassOop 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, klassOop 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, klassOop 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);
+};
+
+// 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(symbolOop 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* f = (oop*)addr;
+      oop o = *f;
+
+      // reflection and sun.misc.Unsafe classes may have a reference to a
+      // klassOop so filter it out.
+      if (o != NULL && o->is_klass()) {
+        o = NULL;
+      }
+
+      // FIXME: When sharing is enabled we don't emit field references to objects
+      // in shared spaces. We can remove this once we write records for the classes
+      // and strings that are shared.
+      if (o != NULL && o->is_shared()) {
+        o = NULL;
+      }
+      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(klassOop k) {
+  HandleMark hm;
+  instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k);
+
+  int size = 0;
+
+  for (FieldStream fld(ikh, false, false); !fld.eos(); fld.next()) {
+    if (!fld.access_flags().is_static()) {
+      symbolOop 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 (u4)size;
+}
+
+// dumps static fields of the given class
+void DumperSupport::dump_static_fields(DumpWriter* writer, klassOop 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()) {
+      symbolOop sig = fld.signature();
+
+      writer->write_objectID(fld.name());   // name
+      writer->write_u1(sig2tag(sig));       // type
+
+      // value
+      int offset = fld.offset();
+      address addr = (address)k + 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()) {
+      symbolOop 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, klassOop 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()) {
+      symbolOop sig = fld.signature();
+
+      writer->write_objectID(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) {
+  klassOop 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(Klass::cast(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, klassOop k) {
+  Klass* klass = Klass::cast(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
+  klassOop java_super = ik->java_super();
+  if (java_super == NULL) {
+    writer->write_objectID(NULL);
+  } else {
+    writer->write_classID(Klass::cast(java_super));
+  }
+
+  writer->write_objectID(ik->class_loader());
+  writer->write_objectID(ik->signers());
+  writer->write_objectID(ik->protection_domain());
+
+  // reserved
+  writer->write_objectID(NULL);
+  writer->write_objectID(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 = Klass::cast(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(Klass::cast(java_super));
+
+    writer->write_objectID(ik->class_loader());
+    writer->write_objectID(ik->signers());
+    writer->write_objectID(ik->protection_domain());
+
+    writer->write_objectID(NULL);    // reserved
+    writer->write_objectID(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, klassOop k) {
+ // array classes
+ while (k != NULL) {
+    Klass* klass = Klass::cast(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
+    klassOop java_super = klass->java_super();
+    assert(java_super != NULL, "checking");
+    writer->write_classID(Klass::cast(java_super));
+
+    writer->write_objectID(NULL);    // loader
+    writer->write_objectID(NULL);    // signers
+    writer->write_objectID(NULL);    // protection domain
+
+    writer->write_objectID(NULL);    // reserved
+    writer->write_objectID(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) {
+
+  // filter this
+  if (array->klass() == Universe::systemObjArrayKlassObj()) return;
+
+  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(Klass::cast(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
+  int length_in_bytes = array->length() * type2aelembytes[type];
+  assert(length_in_bytes > 0, "nothing to copy");
+
+  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();
+  }
+}
+
+
+// Support class used to generate HPROF_UTF8 records from the entries in the
+// SymbolTable.
+
+class SymbolTableDumper : public OopClosure {
+ private:
+  DumpWriter* _writer;
+  DumpWriter* writer() const                { return _writer; }
+ public:
+  SymbolTableDumper(DumpWriter* writer)     { _writer = writer; }
+  void do_oop(oop* obj_p);
+};
+
+void SymbolTableDumper::do_oop(oop* obj_p) {
+  ResourceMark rm;
+  symbolOop sym = (symbolOop)*obj_p;
+
+  int len = sym->utf8_length();
+  if (len > 0) {
+    char* s = sym->as_utf8();
+    DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
+    writer()->write_objectID(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;
+  DumpWriter* writer() const                { return _writer; }
+ public:
+  JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) {
+    _writer = writer;
+    _thread_serial_num = thread_serial_num;
+  }
+  void do_oop(oop* obj_p);
+};
+
+
+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)-1); // empty
+  }
+}
+
+
+// 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 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);
+  }
+};
+
+
+// Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records
+
+class StickyClassDumper : public OopClosure {
+ private:
+  DumpWriter* _writer;
+  DumpWriter* writer() const                { return _writer; }
+ public:
+  StickyClassDumper(DumpWriter* writer) {
+    _writer = writer;
+  }
+  void do_oop(oop* obj_p);
+};
+
+void StickyClassDumper::do_oop(oop* obj_p) {
+  if (*obj_p != NULL) {
+    oop o = *obj_p;
+    if (o->is_klass()) {
+      klassOop k = klassOop(o);
+      if (Klass::cast(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;
+
+  // ignore KlassKlass objects
+  if (o->is_klass()) 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;
+    }
+  }
+
+  // create a HPROF_GC_INSTANCE record for each object
+  if (o->is_instance()) {
+    DumperSupport::dump_instance(writer(), o);
+    mark_end_of_record();
+  } else {
+    // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
+    if (o->is_objArray()) {
+      DumperSupport::dump_object_array(writer(), objArrayOop(o));
+      mark_end_of_record();
+    } else {
+      // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
+      if (o->is_typeArray()) {
+        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:
+  DumpWriter* _writer;
+  bool _gc_before_heap_dump;
+  bool _is_segmented_dump;
+  jlong _dump_start;
+
+  // accessors
+  DumpWriter* writer() const                    { return _writer; }
+  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(klassOop k);
+
+  // writes a HPROF_GC_CLASS_DUMP record for the given class
+  // (and each array class too)
+  static void do_class_dump(klassOop 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(klassOop k);
+
+  // HPROF_GC_ROOT_THREAD_OBJ records
+  void do_thread(JavaThread* thread, u4 thread_serial_num);
+  void do_threads();
+
+  // 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) :
+    VM_GC_Operation(0 /* total collections,      dummy, ignored */,
+                    0 /* total full collections, dummy, ignored */,
+                    gc_before_heap_dump) {
+    _writer = writer;
+    _gc_before_heap_dump = gc_before_heap_dump;
+    _is_segmented_dump = false;
+    _dump_start = (jlong)-1;
+  }
+
+  VMOp_Type type() const { return VMOp_HeapDumper; }
+  // used to mark sub-record boundary
+  void check_segment_length();
+  void doit();
+};
+
+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
+    jlong dump_end = writer()->current_offset();
+    jlong dump_len = (dump_end - dump_start() - 4);
+
+    // record length must fit in a u4
+    if (dump_len > (jlong)(4L*(jlong)G)) {
+      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(-((long) 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
+      jlong dump_end = writer()->bytes_written() + writer()->bytes_unwritten();
+      assert(dump_end == writer()->current_offset(), "checking");
+      jlong dump_len = (dump_end - dump_start() - 4);
+      assert(dump_len >= 0 && dump_len <= max_juint, "bad dump length");
+
+      if (dump_len > (jlong)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(klassOop k) {
+  static u4 class_serial_num = 0;
+
+  VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation());
+  DumpWriter* writer = dumper->writer();
+
+  // 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 = Klass::cast(k);
+    writer->write_classID(klass);
+
+    writer->write_u4(STACK_TRACE_ID);
+
+    // class name ID
+    symbolOop name = klass->name();
+    writer->write_objectID(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(klassOop k) {
+  VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation());
+  DumpWriter* writer = dumper->writer();
+  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(klassOop k) {
+  VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation());
+  DumpWriter* writer = dumper->writer();
+  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
+void 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");
+
+  // JNI locals for the top frame
+  java_thread->active_handles()->oops_do(&blk);
+
+  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);
+
+    while (vf != NULL) {
+      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)-1); // empty
+              }
+            }
+          }
+        }
+      } else {
+
+        // externalVFrame - if it's an entry frame then report any JNI locals
+        // as roots
+        frame* fr = vf->frame_pointer();
+        assert(fr != NULL, "sanity check");
+        if (fr->is_entry_frame()) {
+          fr->entry_frame_call_wrapper()->handles()->oops_do(&blk);
+        }
+      }
+
+      vf = vf->sender();
+    }
+  }
+}
+
+
+// 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() {
+  u4 thread_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()) {
+      ++thread_serial_num;
+
+      writer()->write_u1(HPROF_GC_ROOT_THREAD_OBJ);
+      writer()->write_objectID(threadObj);
+      writer()->write_u4(thread_serial_num);
+      writer()->write_u4(STACK_TRACE_ID);
+
+      do_thread(thread, thread_serial_num);
+    }
+  }
+}
+
+
+// The VM operation that dumps the heap. The dump consists of the following
+// records:
+//
+//  HPROF_HEADER
+//  HPROF_TRACE
+//  [HPROF_UTF8]*
+//  [HPROF_LOAD_CLASS]*
+//  [HPROF_GC_CLASS_DUMP]*
+//  HPROF_HEAP_DUMP
+//
+// The HPROF_TRACE record after the header is "dummy trace" record which does
+// not include any frames. Other records which require a stack trace ID will
+// specify the trace ID of this record (1). It also means we can run HAT without
+// needing the -stack false option.
+//
+// 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();
+  if (_gc_before_heap_dump) {
+    ch->collect_as_vm_thread(GCCause::_heap_dump);
+  } else {
+    // make the heap parsable (no need to retire TLABs)
+    ch->ensure_parsability(false);
+  }
+
+  // Write the file header - use 1.0.2 for large heaps, otherwise 1.0.1
+  size_t used;
+  const char* header;
+#ifndef SERIALGC
+  if (Universe::heap()->kind() == CollectedHeap::GenCollectedHeap) {
+    used = GenCollectedHeap::heap()->used();
+  } else {
+    used = ParallelScavengeHeap::heap()->used();
+  }
+#else // SERIALGC
+  used = GenCollectedHeap::heap()->used();
+#endif // SERIALGC
+  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_TRACE record without any frames
+  DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4));
+  writer()->write_u4(STACK_TRACE_ID);
+  writer()->write_u4(0);                    // thread number
+  writer()->write_u4(0);                    // frame count
+
+  // HPROF_UTF8 records
+  SymbolTableDumper sym_dumper(writer());
+  SymbolTable::oops_do(&sym_dumper);
+
+  // write HPROF_LOAD_CLASS records
+  SystemDictionary::classes_do(&do_load_class);
+  Universe::basic_type_classes_do(&do_load_class);
+
+  // write HPROF_HEAP_DUMP or HPROF_HEAP_DUMP_SEGMENT
+  write_dump_header();
+
+  // Writes HPROF_GC_CLASS_DUMP records
+  SystemDictionary::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()->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_oops_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();
+}
+
+
+// dump the heap to given path.
+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);
+  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) {
+      char msg[256];
+      sprintf(msg, "Heap dump file created [%s bytes in %3.3f secs]",
+        os::jlong_format_specifier(), timer()->seconds());
+      tty->print_cr(msg, writer.bytes_written());
+    } 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 error reporting
+void HeapDumper::dump_heap() {
+  static char path[JVM_MAXPATHLEN];
+
+  // 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.
+  bool use_default_filename = true;
+  if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') {
+    path[0] = '\0'; // HeapDumpPath=<file> not specified
+  } else {
+    assert(strlen(HeapDumpPath) < sizeof(path), "HeapDumpPath too long");
+    strcpy(path, HeapDumpPath);
+    // check if the path is a directory (must exist)
+    DIR* dir = os::opendir(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(path) >= fs_len) {
+        char* end = path;
+        end += (strlen(path) - fs_len);
+        if (strcmp(end, os::file_separator()) != 0) {
+          assert(strlen(path) + strlen(os::file_separator()) < sizeof(path),
+            "HeapDumpPath too long");
+          strcat(path, os::file_separator());
+        }
+      }
+    }
+  }
+  // If HeapDumpPath wasn't a file name then we append the default name
+  if (use_default_filename) {
+    char fn[32];
+    sprintf(fn, "java_pid%d.hprof", os::current_process_id());
+    assert(strlen(path) + strlen(fn) < sizeof(path), "HeapDumpPath too long");
+    strcat(path, fn);
+  }
+
+  HeapDumper dumper(false /* no GC before heap dump */,
+                    true  /* send to tty */);
+  dumper.dump(path);
+}