C++ Arena::Amalloc方法代码示例

// ------------------------------------------------------------------
// ciMethod::load_code
//
// Load the bytecodes and exception handler table for this method.
void ciMethod::load_code() {
  VM_ENTRY_MARK;
  assert(is_loaded(), "only loaded methods have code");

  methodOop me = get_methodOop();
  Arena* arena = CURRENT_THREAD_ENV->arena();

  // Load the bytecodes.
  _code = (address)arena->Amalloc(code_size());
  memcpy(_code, me->code_base(), code_size());

  // Revert any breakpoint bytecodes in ci's copy
  if (me->number_of_breakpoints() > 0) {
    BreakpointInfo* bp = instanceKlass::cast(me->method_holder())->breakpoints();
    for (; bp != NULL; bp = bp->next()) {
      if (bp->match(me)) {
        code_at_put(bp->bci(), bp->orig_bytecode());
      }
    }
  }

  // And load the exception table.
  typeArrayOop exc_table = me->exception_table();

  // Allocate one extra spot in our list of exceptions.  This
  // last entry will be used to represent the possibility that
  // an exception escapes the method.  See ciExceptionHandlerStream
  // for details.
  _exception_handlers =
    (ciExceptionHandler**)arena->Amalloc(sizeof(ciExceptionHandler*)
                                         * (_handler_count + 1));
  if (_handler_count > 0) {
    for (int i=0; i<_handler_count; i++) {
      int base = i*4;
      _exception_handlers[i] = new (arena) ciExceptionHandler(
                                holder(),
            /* start    */      exc_table->int_at(base),
            /* limit    */      exc_table->int_at(base+1),
            /* goto pc  */      exc_table->int_at(base+2),
            /* cp index */      exc_table->int_at(base+3));
    }
  }

  // Put an entry at the end of our list to represent the possibility
  // of exceptional exit.
  _exception_handlers[_handler_count] =
    new (arena) ciExceptionHandler(holder(), 0, code_size(), -1, 0);

  if (CIPrintMethodCodes) {
    print_codes();
  }
}

void ciMethodData::load_data() {
  MethodData* mdo = get_MethodData();
  if (mdo == NULL) {
    return;
  }

  // To do: don't copy the data if it is not "ripe" -- require a minimum #
  // of invocations.

  // Snapshot the data -- actually, take an approximate snapshot of
  // the data.  Any concurrently executing threads may be changing the
  // data as we copy it.
  Copy::disjoint_words((HeapWord*) mdo,
                       (HeapWord*) &_orig,
                       sizeof(_orig) / HeapWordSize);
  Arena* arena = CURRENT_ENV->arena();
  _data_size = mdo->data_size();
  _extra_data_size = mdo->extra_data_size();
  int total_size = _data_size + _extra_data_size;
  _data = (intptr_t *) arena->Amalloc(total_size);
  Copy::disjoint_words((HeapWord*) mdo->data_base(), (HeapWord*) _data, total_size / HeapWordSize);

  // Traverse the profile data, translating any oops into their
  // ci equivalents.
  ResourceMark rm;
  ciProfileData* ci_data = first_data();
  ProfileData* data = mdo->first_data();
  while (is_valid(ci_data)) {
    ci_data->translate_from(data);
    ci_data = next_data(ci_data);
    data = mdo->next_data(data);
  }
  if (mdo->parameters_type_data() != NULL) {
    _parameters = data_layout_at(mdo->parameters_type_data_di());
    ciParametersTypeData* parameters = new ciParametersTypeData(_parameters);
    parameters->translate_from(mdo->parameters_type_data());
  }

  load_extra_data();

  // Note:  Extra data are all BitData, and do not need translation.
  _current_mileage = MethodData::mileage_of(mdo->method());
  _invocation_counter = mdo->invocation_count();
  _backedge_counter = mdo->backedge_count();
  _state = mdo->is_mature()? mature_state: immature_state;

  _eflags = mdo->eflags();
  _arg_local = mdo->arg_local();
  _arg_stack = mdo->arg_stack();
  _arg_returned  = mdo->arg_returned();
#ifndef PRODUCT
  if (ReplayCompiles) {
    ciReplay::initialize(this);
  }
#endif
}

void ciMethodData::load_data() {
  methodDataOop mdo = get_methodDataOop();
  if (mdo == NULL) return;

  // To do: don't copy the data if it is not "ripe" -- require a minimum #
  // of invocations.

  // Snapshot the data -- actually, take an approximate snapshot of
  // the data.  Any concurrently executing threads may be changing the
  // data as we copy it.
  int skip_header = oopDesc::header_size();
  Copy::disjoint_words((HeapWord*) mdo              + skip_header,
                       (HeapWord*) &_orig           + skip_header,
                       sizeof(_orig) / HeapWordSize - skip_header);
  DEBUG_ONLY(*_orig.adr_method() = NULL);  // no dangling oops, please
  Arena* arena = CURRENT_ENV->arena();
  _data_size = mdo->data_size();
  _extra_data_size = mdo->extra_data_size();
  int total_size = _data_size + _extra_data_size;
  _data = (intptr_t *) arena->Amalloc(total_size);
  Copy::disjoint_words((HeapWord*) mdo->data_base(), (HeapWord*) _data, total_size / HeapWordSize);

  // Traverse the profile data, translating any oops into their
  // ci equivalents.
  ResourceMark rm;
  ciProfileData* ci_data = first_data();
  ProfileData* data = mdo->first_data();
  while (is_valid(ci_data)) {
    ci_data->translate_from(data);
    ci_data = next_data(ci_data);
    data = mdo->next_data(data);
  }
  // Note:  Extra data are all BitData, and do not need translation.
  _current_mileage = methodDataOopDesc::mileage_of(mdo->method());
  _state = mdo->is_mature()? mature_state: immature_state;

  _eflags = mdo->eflags();
  _arg_local = mdo->arg_local();
  _arg_stack = mdo->arg_stack();
  _arg_returned  = mdo->arg_returned();
}