C++ methodHandle::method_holder方法代码示例

void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, methodHandle method, int index) {
  assert(method->method_holder()->verify_itable_index(index), "");
  assert(invoke_code == Bytecodes::_invokeinterface, "");
  InstanceKlass* interf = method->method_holder();
  assert(interf->is_interface(), "must be an interface");
  assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
  set_f1(interf);
  set_f2(index);
  set_method_flags(as_TosState(method->result_type()),
                   0,  // no option bits
                   method()->size_of_parameters());
  set_bytecode_1(Bytecodes::_invokeinterface);
}

// Check if there are any JVM TI prefixes which have been applied to the native method name.
// If any are found, remove them before attemping the look up of the
// native implementation again.
// See SetNativeMethodPrefix in the JVM TI Spec for more details.
address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {
  ResourceMark rm(THREAD);

  int prefix_count;
  char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
  char* in_name = method->name()->as_C_string();
  char* wrapper_name = in_name;
  // last applied prefix will be first -- go backwards
  for (int i = prefix_count-1; i >= 0; i--) {
    char* prefix = prefixes[i];
    size_t prefix_len = strlen(prefix);
    if (strncmp(prefix, wrapper_name, prefix_len) == 0) {
      // has this prefix remove it
      wrapper_name += prefix_len;
    }
  }
  if (wrapper_name != in_name) {
    // we have a name for a wrapping method
    int wrapper_name_len = (int)strlen(wrapper_name);
    TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len);
    if (wrapper_symbol != NULL) {
      KlassHandle kh(method->method_holder());
      methodOop wrapper_method = Klass::cast(kh())->lookup_method(wrapper_symbol,
                                                                  method->signature());
      if (wrapper_method != NULL && !wrapper_method->is_native()) {
        // we found a wrapper method, use its native entry
        method->set_is_prefixed_native();
        return lookup_entry(wrapper_method, in_base_library, THREAD);
      }
    }
  }
  return NULL;
}

void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
  klassOop interf = method->method_holder();
  assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
  set_f1(interf);
  set_f2(index);
  set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());
  set_bytecode_1(Bytecodes::_invokeinterface);  
}

// Fill in the StackFrameInfo at the given index in frames_array
void JavaFrameStream::fill_frame(int index, objArrayHandle  frames_array,
                                 const methodHandle& method, TRAPS) {
    if (_need_method_info) {
        Handle stackFrame(THREAD, frames_array->obj_at(index));
        fill_stackframe(stackFrame, method);
    } else {
        frames_array->obj_at_put(index, method->method_holder()->java_mirror());
    }
}

address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
  address entry;
  // Compute complete JNI name for style
  stringStream st;
  if (os_style) os::print_jni_name_prefix_on(&st, args_size);
  st.print_raw(pure_name);
  st.print_raw(long_name);
  if (os_style) os::print_jni_name_suffix_on(&st, args_size);
  char* jni_name = st.as_string();

  // If the loader is null we have a system class, so we attempt a lookup in
  // the native Java library. This takes care of any bootstrapping problems.
  // Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
  // gets found the first time around - otherwise an infinite loop can occure. This is
  // another VM/library dependency
  Handle loader(THREAD,
                instanceKlass::cast(method->method_holder())->class_loader());
  if (loader.is_null()) {
    entry = lookup_special_native(jni_name);
    if (entry == NULL) {
       entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
    }
    if (entry != NULL) {
      in_base_library = true;
      return entry;
    }
  }

  // Otherwise call static method findNative in ClassLoader
  KlassHandle   klass (THREAD, SystemDictionary::ClassLoader_klass());
  Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);

  JavaValue result(T_LONG);
  JavaCalls::call_static(&result,
                         klass,
                         vmSymbols::findNative_name(),
                         vmSymbols::classloader_string_long_signature(),
                         // Arguments
                         loader,
                         name_arg,
                         CHECK_NULL);
  entry = (address) (intptr_t) result.get_jlong();

  if (entry == NULL) {
    // findNative didn't find it, if there are any agent libraries look in them
    AgentLibrary* agent;
    for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
      entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
      if (entry != NULL) {
        return entry;
      }
    }
  }

  return entry;
}

void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
  assert(!is_secondary_entry(), "");
  klassOop interf = method->method_holder();
  assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
  assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
  set_f1(interf);
  set_f2(index);
  set_method_flags(as_TosState(method->result_type()),
                   0,  // no option bits
                   method()->size_of_parameters());
  set_bytecode_1(Bytecodes::_invokeinterface);
}

void JavaCalls::call_default_constructor(JavaThread* thread, methodHandle method, Handle receiver, TRAPS) {
  assert(method->name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructor");
  assert(method->signature() == vmSymbols::void_method_signature(), "Should only be called for default constructor");

  InstanceKlass* ik = method->method_holder();
  if (ik->is_initialized() && ik->has_vanilla_constructor()) {
    // safe to skip constructor call
  } else {
    static JavaValue result(T_VOID);
    JavaCallArguments args(receiver);
    call(&result, method, &args, CHECK);
  }
}

address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
  if (!method->has_native_function()) {
    address entry = lookup_base(method, in_base_library, CHECK_NULL);
    method->set_native_function(entry,
      Method::native_bind_event_is_interesting);
    // -verbose:jni printing
    if (PrintJNIResolving) {
      ResourceMark rm(THREAD);
      tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
        method->method_holder()->external_name(),
        method->name()->as_C_string());
    }
  }
  return method->native_function();
}

/**
 * 为给定的本地java方法寻找对应的函数入口地址
 */
address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
  if (!method->has_native_function()) {
	printf("%s[%d] [tid: %lu]: 试图查找本地方法[%s.%s]..\n", __FILE__, __LINE__, pthread_self(), Klass::cast(method->method_holder())->external_name(), method->name()->as_C_string());
    address entry = lookup_base(method, in_base_library, CHECK_NULL);

    method->set_native_function(entry, methodOopDesc::native_bind_event_is_interesting);

    // -verbose:jni printing
    if (PrintJNIResolving) {
      ResourceMark rm(THREAD);
      tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
        Klass::cast(method->method_holder())->external_name(),
        method->name()->as_C_string());
    }
  }

  return method->native_function();
}

// Fill StackFrameInfo with declaringClass and bci and initialize memberName
void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method) {
    java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
    java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci());
}

void JvmtiClassFileReconstituter::copy_bytecodes(methodHandle mh,
                                                 unsigned char* bytecodes) {
  // use a BytecodeStream to iterate over the bytecodes. JVM/fast bytecodes
  // and the breakpoint bytecode are converted to their original bytecodes.

  BytecodeStream bs(mh);

  unsigned char* p = bytecodes;
  Bytecodes::Code code;
  bool is_rewritten = mh->method_holder()->is_rewritten();

  while ((code = bs.next()) >= 0) {
    assert(Bytecodes::is_java_code(code), "sanity check");
    assert(code != Bytecodes::_breakpoint, "sanity check");

    // length of bytecode (mnemonic + operands)
    address bcp = bs.bcp();
    int     len = bs.instruction_size();
    assert(len > 0, "length must be > 0");

    // copy the bytecodes
    *p = (unsigned char) (bs.is_wide()? Bytecodes::_wide : code);
    if (len > 1) {
      memcpy(p+1, bcp+1, len-1);
    }

    // During linking the get/put and invoke instructions are rewritten
    // with an index into the constant pool cache. The original constant
    // pool index must be returned to caller.  Rewrite the index.
    if (is_rewritten && len > 1) {
      bool is_wide = false;
      switch (code) {
      case Bytecodes::_getstatic       :  // fall through
      case Bytecodes::_putstatic       :  // fall through
      case Bytecodes::_getfield        :  // fall through
      case Bytecodes::_putfield        :  // fall through
      case Bytecodes::_invokevirtual   :  // fall through
      case Bytecodes::_invokespecial   :  // fall through
      case Bytecodes::_invokestatic    :  // fall through
      case Bytecodes::_invokedynamic   :  // fall through
      case Bytecodes::_invokeinterface : {
        assert(len == 3 ||
               (code == Bytecodes::_invokeinterface && len == 5) ||
               (code == Bytecodes::_invokedynamic   && len == 5),
               "sanity check");

        int cpci = Bytes::get_native_u2(bcp+1);
        bool is_invokedynamic = (EnableInvokeDynamic && code == Bytecodes::_invokedynamic);
        ConstantPoolCacheEntry* entry;
        if (is_invokedynamic) {
          cpci = Bytes::get_native_u4(bcp+1);
          entry = mh->constants()->invokedynamic_cp_cache_entry_at(cpci);
        } else {
        // cache cannot be pre-fetched since some classes won't have it yet
          entry = mh->constants()->cache()->entry_at(cpci);
        }
        int i = entry->constant_pool_index();
        assert(i < mh->constants()->length(), "sanity check");
        Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
        if (is_invokedynamic)  *(p+3) = *(p+4) = 0;
        break;
      }
      case Bytecodes::_ldc_w:
        is_wide = true; // fall through
      case Bytecodes::_ldc: {
        if (bs.raw_code() == Bytecodes::_fast_aldc || bs.raw_code() == Bytecodes::_fast_aldc_w) {
          int cpci = is_wide ? Bytes::get_native_u2(bcp+1) : (u1)(*(bcp+1));
          int i = mh->constants()->object_to_cp_index(cpci);
          assert(i < mh->constants()->length(), "sanity check");
          if (is_wide) {
            Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
          } else {
            *(p+1) = (u1)i;
          }
        }
        break;
        }
      }
    }

    p += len;
  }
}

void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, methodHandle method, int index) {
  // either the method is a miranda or its holder should accept the given index
  assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
  // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
  set_direct_or_vtable_call(invoke_code, method, index);
}

void CodeBuffer::finalize_oop_references(methodHandle mh) {
  No_Safepoint_Verifier nsv;

  GrowableArray<oop> oops;

  // Make sure that immediate metadata records something in the OopRecorder
  for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) {
    // pull code out of each section
    CodeSection* cs = code_section(n);
    if (cs->is_empty())  continue;  // skip trivial section
    RelocIterator iter(cs);
    while (iter.next()) {
      if (iter.type() == relocInfo::metadata_type) {
        metadata_Relocation* md = iter.metadata_reloc();
        if (md->metadata_is_immediate()) {
          Metadata* m = md->metadata_value();
          if (oop_recorder()->is_real(m)) {
            if (m->is_methodData()) {
              m = ((MethodData*)m)->method();
            }
            if (m->is_method()) {
              m = ((Method*)m)->method_holder();
            }
            if (m->is_klass()) {
              append_oop_references(&oops, (Klass*)m);
            } else {
              // XXX This will currently occur for MDO which don't
              // have a backpointer.  This has to be fixed later.
              m->print();
              ShouldNotReachHere();
            }
          }
        }
      }
    }
  }

  if (!oop_recorder()->is_unused()) {
    for (int i = 0; i < oop_recorder()->metadata_count(); i++) {
      Metadata* m = oop_recorder()->metadata_at(i);
      if (oop_recorder()->is_real(m)) {
        if (m->is_methodData()) {
          m = ((MethodData*)m)->method();
        }
        if (m->is_method()) {
          m = ((Method*)m)->method_holder();
        }
        if (m->is_klass()) {
          append_oop_references(&oops, (Klass*)m);
        } else {
          m->print();
          ShouldNotReachHere();
        }
      }
    }

  }

  // Add the class loader of Method* for the nmethod itself
  append_oop_references(&oops, mh->method_holder());

  // Add any oops that we've found
  Thread* thread = Thread::current();
  for (int i = 0; i < oops.length(); i++) {
    oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i)));
  }
}