hotspot/src/share/vm/utilities/elfFile.hpp
author tonyp
Wed, 19 Jan 2011 19:30:42 -0500
changeset 7923 fc200fcd4e05
parent 7447 32c42d627f41
child 10565 dc90c239f4ec
permissions -rw-r--r--
6977804: G1: remove the zero-filling thread Summary: This changeset removes the zero-filling thread from G1 and collapses the two free region lists we had before (the "free" and "unclean" lists) into one. The new free list uses the new heap region sets / lists abstractions that we'll ultimately use it to keep track of all regions in the heap. A heap region set was also introduced for the humongous regions. Finally, this change increases the concurrency between the thread that completes freeing regions (after a cleanup pause) and the rest of the system (before we'd have to wait for said thread to complete before allocating a new region). The changest also includes a lot of refactoring and code simplification. Reviewed-by: jcoomes, johnc

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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#ifndef __ELF_FILE_HPP
#define __ELF_FILE_HPP

#ifndef _WINDOWS

#include <elf.h>
#include <stdio.h>

#ifdef _LP64

typedef Elf64_Half      Elf_Half;
typedef Elf64_Word      Elf_Word;
typedef Elf64_Off       Elf_Off;
typedef Elf64_Addr      Elf_Addr;

typedef Elf64_Ehdr      Elf_Ehdr;
typedef Elf64_Shdr      Elf_Shdr;
typedef Elf64_Sym       Elf_Sym;

#define ELF_ST_TYPE ELF64_ST_TYPE

#else

typedef Elf32_Half      Elf_Half;
typedef Elf32_Word      Elf_Word;
typedef Elf32_Off       Elf_Off;
typedef Elf32_Addr      Elf_Addr;


typedef Elf32_Ehdr      Elf_Ehdr;
typedef Elf32_Shdr      Elf_Shdr;
typedef Elf32_Sym       Elf_Sym;

#define ELF_ST_TYPE ELF32_ST_TYPE
#endif

#include "globalDefinitions.hpp"
#include "memory/allocation.hpp"
#include "utilities/decoder.hpp"


class ElfStringTable;
class ElfSymbolTable;


// On Solaris/Linux platforms, libjvm.so does contain all private symbols.
// ElfFile is basically an elf file parser, which can lookup the symbol
// that is the nearest to the given address.
// Beware, this code is called from vm error reporting code, when vm is already
// in "error" state, so there are scenarios, lookup will fail. We want this
// part of code to be very defensive, and bait out if anything went wrong.

class ElfFile: public CHeapObj {
  friend class Decoder;
 public:
  ElfFile(const char* filepath);
  ~ElfFile();

  const char* decode(address addr, int* offset);
  const char* filepath() {
    return m_filepath;
  }

  bool same_elf_file(const char* filepath) {
    assert(filepath, "null file path");
    assert(m_filepath, "already out of memory");
    return (m_filepath && !strcmp(filepath, m_filepath));
  }

  Decoder::decoder_status get_status() {
    return m_status;
  }

 private:
  // sanity check, if the file is a real elf file
  bool is_elf_file(Elf_Ehdr&);

  // load string tables from the elf file
  bool load_tables();

  // string tables are stored in a linked list
  void add_string_table(ElfStringTable* table);

  // symbol tables are stored in a linked list
  void add_symbol_table(ElfSymbolTable* table);

  // return a string table at specified section index
  ElfStringTable* get_string_table(int index);

  // look up an address and return the nearest symbol
  const char* look_up(Elf_Shdr shdr, address addr, int* offset);

 protected:
    ElfFile*         m_next;

 private:
  // file
  const char* m_filepath;
  FILE* m_file;

  // Elf header
  Elf_Ehdr            m_elfHdr;

  // symbol tables
  ElfSymbolTable*     m_symbol_tables;

  // string tables
  ElfStringTable*     m_string_tables;

  Decoder::decoder_status  m_status;
};

#endif // _WINDOWS

#endif // __ELF_FILE_HPP