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Java example source code file (jhelper.d)

This example Java source code file (jhelper.d) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

addr, debug, mark_line, null, offset_codeblob_name, offset_codeheap_memory, offset_codeheap_segmap, offset_symbol_body, offset_symbol_length, offset_virtualspace_high, offset_virtualspace_low, same, size_constantpool, stack_bias

The jhelper.d Java example source code

/*
 * Copyright (c) 2003, 2013, 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.
 *  
 */

/* This file is auto-generated */
#include "JvmOffsetsIndex.h"

#define DEBUG

#ifdef DEBUG
#define MARK_LINE this->line = __LINE__
#else
#define MARK_LINE 
#endif

#ifdef _LP64
#define STACK_BIAS 0x7ff
#define pointer uint64_t
#else
#define STACK_BIAS 0
#define pointer uint32_t
#endif

extern pointer __JvmOffsets;

extern pointer __1cJCodeCacheF_heap_;
extern pointer __1cIUniverseO_collectedHeap_;

extern pointer __1cHnmethodG__vtbl_;
extern pointer __1cGMethodG__vtbl_;
extern pointer __1cKBufferBlobG__vtbl_;

#define copyin_ptr(ADDR)    *(pointer*)  copyin((pointer) (ADDR), sizeof(pointer))
#define copyin_uchar(ADDR)  *(uchar_t*)  copyin((pointer) (ADDR), sizeof(uchar_t))
#define copyin_uint16(ADDR) *(uint16_t*) copyin((pointer) (ADDR), sizeof(uint16_t))
#define copyin_uint32(ADDR) *(uint32_t*) copyin((pointer) (ADDR), sizeof(uint32_t))
#define copyin_int32(ADDR)  *(int32_t*)  copyin((pointer) (ADDR), sizeof(int32_t))
#define copyin_uint8(ADDR)  *(uint8_t*)  copyin((pointer) (ADDR), sizeof(uint8_t))

#define SAME(x) x
#define copyin_offset(JVM_CONST)  JVM_CONST = \
	copyin_int32(JvmOffsetsPtr + SAME(IDX_)JVM_CONST * sizeof(int32_t))

int init_done;

dtrace:helper:ustack:
{
  MARK_LINE;
  this->done = 0;
  /*
   * TBD:
   * Here we initialize init_done, otherwise jhelper does not work.
   * Therefore, copyin_offset() statements work multiple times now.
   * There is a hope we could avoid it in the future, and so,
   * this initialization can be removed.
   */
  init_done  = 0;
  this->error = (char *) NULL;
  this->result = (char *) NULL;
  this->isMethod = 0;
  this->codecache = 0;
  this->klass = (pointer) NULL;
  this->vtbl  = (pointer) NULL;
  this->suffix = '\0';
}

dtrace:helper:ustack:
{
  MARK_LINE;
  /* Initialization of JvmOffsets constants */
  JvmOffsetsPtr = (pointer) &``__JvmOffsets;
}

dtrace:helper:ustack:
/!init_done && !this->done/
{
  MARK_LINE;
  init_done = 1;

  copyin_offset(COMPILER);
  copyin_offset(OFFSET_CollectedHeap_reserved);
  copyin_offset(OFFSET_MemRegion_start);
  copyin_offset(OFFSET_MemRegion_word_size);
  copyin_offset(SIZE_HeapWord);

  copyin_offset(OFFSET_interpreter_frame_method);
  copyin_offset(OFFSET_Klass_name);
  copyin_offset(OFFSET_ConstantPool_pool_holder);

  copyin_offset(OFFSET_HeapBlockHeader_used);
  copyin_offset(OFFSET_oopDesc_metadata);

  copyin_offset(OFFSET_Symbol_length);
  copyin_offset(OFFSET_Symbol_body);

  copyin_offset(OFFSET_Method_constMethod);
  copyin_offset(OFFSET_ConstMethod_constants);
  copyin_offset(OFFSET_ConstMethod_name_index);
  copyin_offset(OFFSET_ConstMethod_signature_index);

  copyin_offset(OFFSET_CodeHeap_memory);
  copyin_offset(OFFSET_CodeHeap_segmap);
  copyin_offset(OFFSET_CodeHeap_log2_segment_size);

  copyin_offset(OFFSET_VirtualSpace_low);
  copyin_offset(OFFSET_VirtualSpace_high);

  copyin_offset(OFFSET_CodeBlob_name);

  copyin_offset(OFFSET_nmethod_method);
  copyin_offset(SIZE_HeapBlockHeader);
  copyin_offset(SIZE_oopDesc);
  copyin_offset(SIZE_ConstantPool);

  copyin_offset(OFFSET_NarrowPtrStruct_base);
  copyin_offset(OFFSET_NarrowPtrStruct_shift);

  /*
   * The PC to translate is in arg0.
   */
  this->pc = arg0;

  /*
   * The methodPtr is in %l2 on SPARC.  This can be found at
   * offset 8 from the frame pointer on 32-bit processes.
   */
#if   defined(__sparc)
  this->methodPtr = copyin_ptr(arg1 + 2 * sizeof(pointer) + STACK_BIAS);
#elif defined(__i386) || defined(__amd64)
  this->methodPtr = copyin_ptr(arg1 + OFFSET_interpreter_frame_method);
#else
#error "Don't know architecture"
#endif

  this->CodeCache_heap_address = copyin_ptr(&``__1cJCodeCacheF_heap_);

  this->CodeCache_low = copyin_ptr(this->CodeCache_heap_address + 
      OFFSET_CodeHeap_memory + OFFSET_VirtualSpace_low);

  this->CodeCache_high = copyin_ptr(this->CodeCache_heap_address +
      OFFSET_CodeHeap_memory + OFFSET_VirtualSpace_high);

  this->CodeCache_segmap_low = copyin_ptr(this->CodeCache_heap_address +
      OFFSET_CodeHeap_segmap + OFFSET_VirtualSpace_low);

  this->CodeCache_segmap_high = copyin_ptr(this->CodeCache_heap_address +
      OFFSET_CodeHeap_segmap + OFFSET_VirtualSpace_high);

  this->CodeHeap_log2_segment_size = copyin_uint32(
      this->CodeCache_heap_address + OFFSET_CodeHeap_log2_segment_size);

  this->Method_vtbl             = (pointer) &``__1cGMethodG__vtbl_;

  /*
   * Get Java heap bounds
   */
  this->Universe_collectedHeap = copyin_ptr(&``__1cIUniverseO_collectedHeap_);
  this->heap_start = copyin_ptr(this->Universe_collectedHeap +
      OFFSET_CollectedHeap_reserved +
      OFFSET_MemRegion_start);
  this->heap_size = SIZE_HeapWord *
    copyin_ptr(this->Universe_collectedHeap +
        OFFSET_CollectedHeap_reserved +
        OFFSET_MemRegion_word_size
        );
  this->heap_end = this->heap_start + this->heap_size;
}

dtrace:helper:ustack:
/!this->done &&
this->CodeCache_low <= this->pc && this->pc < this->CodeCache_high/
{
  MARK_LINE;
  this->codecache = 1;

  /*
   * Find start.
   */
  this->segment = (this->pc - this->CodeCache_low) >>
    this->CodeHeap_log2_segment_size;
  this->block = this->CodeCache_segmap_low;
  this->tag = copyin_uchar(this->block + this->segment);
  "second";
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->tag = copyin_uchar(this->block + this->segment);
  this->segment = this->segment - this->tag;
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->tag = copyin_uchar(this->block + this->segment);
  this->segment = this->segment - this->tag;
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->tag = copyin_uchar(this->block + this->segment);
  this->segment = this->segment - this->tag;
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->tag = copyin_uchar(this->block + this->segment);
  this->segment = this->segment - this->tag;
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->tag = copyin_uchar(this->block + this->segment);
  this->segment = this->segment - this->tag;
}

dtrace:helper:ustack:
/!this->done && this->codecache && this->tag > 0/
{
  MARK_LINE;
  this->error = "<couldn't find start>";
  this->done = 1;
}

dtrace:helper:ustack:
/!this->done && this->codecache/
{
  MARK_LINE;
  this->block = this->CodeCache_low +
    (this->segment << this->CodeHeap_log2_segment_size);
  this->used = copyin_uint32(this->block + OFFSET_HeapBlockHeader_used);
}

dtrace:helper:ustack:
/!this->done && this->codecache && !this->used/
{
  MARK_LINE;
  this->error = "<block not in use>";
  this->done = 1;
}

dtrace:helper:ustack:
/!this->done && this->codecache/
{
  MARK_LINE;
  this->start = this->block + SIZE_HeapBlockHeader;
  this->vtbl = copyin_ptr(this->start);

  this->nmethod_vtbl            = (pointer) &``__1cHnmethodG__vtbl_;
  this->BufferBlob_vtbl         = (pointer) &``__1cKBufferBlobG__vtbl_;
}

dtrace:helper:ustack:
/!this->done && this->vtbl == this->nmethod_vtbl/
{
  MARK_LINE;
  this->methodPtr = copyin_ptr(this->start + OFFSET_nmethod_method);
  this->suffix = '*';
  this->isMethod = 1;
}

dtrace:helper:ustack:
/!this->done && this->vtbl == this->BufferBlob_vtbl/
{
  MARK_LINE;
  this->name = copyin_ptr(this->start + OFFSET_CodeBlob_name);
}


dtrace:helper:ustack:
/!this->done && this->vtbl == this->BufferBlob_vtbl && this->methodPtr != 0/
{
  MARK_LINE;
  this->klass = copyin_ptr(this->methodPtr);
  this->isMethod = this->klass == this->Method_vtbl;
  this->done = !this->isMethod;
}

dtrace:helper:ustack:
/!this->done && !this->isMethod/
{
  MARK_LINE;
  this->name = copyin_ptr(this->start + OFFSET_CodeBlob_name);
  this->result = this->name != 0 ? copyinstr(this->name) : "<CodeBlob>";
  this->done = 1;
}

dtrace:helper:ustack:
/!this->done && this->isMethod/
{
  MARK_LINE;
  this->constMethod = copyin_ptr(this->methodPtr +
      OFFSET_Method_constMethod);

  this->nameIndex = copyin_uint16(this->constMethod +
      OFFSET_ConstMethod_name_index);

  this->signatureIndex = copyin_uint16(this->constMethod +
      OFFSET_ConstMethod_signature_index);

  this->constantPool = copyin_ptr(this->constMethod +
      OFFSET_ConstMethod_constants);

  this->nameSymbol = copyin_ptr(this->constantPool +
      this->nameIndex * sizeof (pointer) + SIZE_ConstantPool);
  /* The symbol is a CPSlot and has lower bit set to indicate metadata */
  this->nameSymbol &= (~1); /* remove metadata lsb */

  this->nameSymbolLength = copyin_uint16(this->nameSymbol +
      OFFSET_Symbol_length);

  this->signatureSymbol = copyin_ptr(this->constantPool +
      this->signatureIndex * sizeof (pointer) + SIZE_ConstantPool);
  this->signatureSymbol &= (~1); /* remove metadata lsb */

  this->signatureSymbolLength = copyin_uint16(this->signatureSymbol +
      OFFSET_Symbol_length);

  this->klassPtr = copyin_ptr(this->constantPool +
      OFFSET_ConstantPool_pool_holder);

  this->klassSymbol = copyin_ptr(this->klassPtr +
      OFFSET_Klass_name);

  this->klassSymbolLength = copyin_uint16(this->klassSymbol +
      OFFSET_Symbol_length);

  /*
   * Enough for three strings, plus the '.', plus the trailing '\0'.
   */
  this->result = (char *) alloca(this->klassSymbolLength +
      this->nameSymbolLength +
      this->signatureSymbolLength + 2 + 1);

  copyinto(this->klassSymbol + OFFSET_Symbol_body,
      this->klassSymbolLength, this->result);

  /*
   * Add the '.' between the class and the name.
   */
  this->result[this->klassSymbolLength] = '.';

  copyinto(this->nameSymbol + OFFSET_Symbol_body,
      this->nameSymbolLength,
      this->result + this->klassSymbolLength + 1);

  copyinto(this->signatureSymbol + OFFSET_Symbol_body,
      this->signatureSymbolLength,
      this->result + this->klassSymbolLength +
      this->nameSymbolLength + 1);

  /*
   * Now we need to add a trailing '\0' and possibly a tag character.
   */
  this->result[this->klassSymbolLength + 1 + 
      this->nameSymbolLength +
      this->signatureSymbolLength] = this->suffix;
  this->result[this->klassSymbolLength + 2 + 
      this->nameSymbolLength +
      this->signatureSymbolLength] = '\0';

  this->done = 1;
}

dtrace:helper:ustack:
/this->done && this->error == (char *) NULL/
{
  this->result;   
}

dtrace:helper:ustack:
/this->done && this->error != (char *) NULL/
{
  this->error;
}

dtrace:helper:ustack:
/!this->done && this->codecache/
{
  this->done = 1;
  "error";
}


dtrace:helper:ustack:
/!this->done/
{
  NULL;
}

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