src/hotspot/share/classfile/javaClasses.cpp

*** 3991,4000 ****
--- 3991,4001 ----
  
  bool java_lang_ClassLoader::offsets_computed = false;
  int  java_lang_ClassLoader::_loader_data_offset = -1;
  int  java_lang_ClassLoader::parallelCapable_offset = -1;
  int  java_lang_ClassLoader::name_offset = -1;
+ int  java_lang_ClassLoader::nameAndId_offset = -1;
  int  java_lang_ClassLoader::unnamedModule_offset = -1;
  
  ClassLoaderData* java_lang_ClassLoader::loader_data(oop loader) {
    assert(loader != NULL && oopDesc::is_oop(loader), "loader must be oop");
    return HeapAccess<>::load_at(loader, _loader_data_offset);
*** 4006,4015 ****
--- 4007,4017 ----
  }
  
  #define CLASSLOADER_FIELDS_DO(macro) \
    macro(parallelCapable_offset, k1, "parallelLockMap",      concurrenthashmap_signature, false); \
    macro(name_offset,            k1, vmSymbols::name_name(), string_signature, false); \
+   macro(nameAndId_offset,       k1, "nameAndId",            string_signature, false); \
    macro(unnamedModule_offset,   k1, "unnamedModule",        module_signature, false); \
    macro(parent_offset,          k1, "parent",               classloader_signature, false)
  
  void java_lang_ClassLoader::compute_offsets() {
    assert(!offsets_computed, "offsets should be initialized only once");
*** 4031,4045 ****
--- 4033,4060 ----
  oop java_lang_ClassLoader::parent(oop loader) {
    assert(is_instance(loader), "loader must be oop");
    return loader->obj_field(parent_offset);
  }
  
+ // Returns the name field of this class loader.  If the name field has not 
+ // been set, null will be returned.  
  oop java_lang_ClassLoader::name(oop loader) {
    assert(is_instance(loader), "loader must be oop");
    return loader->obj_field(name_offset);
  }
  
+ // Returns the nameAndId field of this class loader. The format is
+ // as follows:
+ //   If the defining loader has a name explicitly set then '<loader-name>' @<id>
+ //   If the defining loader has no name then <qualified-class-name> @<id>
+ //   If built-in loader, then omit '@<id>' as there is only one instance.
+ // Use ClassLoader::loader_name_id() to obtain this String as a char*.
+ oop java_lang_ClassLoader::nameAndId(oop loader) {
+   assert(is_instance(loader), "loader must be oop");
+   return loader->obj_field(nameAndId_offset);
+ }
+ 
  bool java_lang_ClassLoader::isAncestor(oop loader, oop cl) {
    assert(is_instance(loader), "loader must be oop");
    assert(cl == NULL || is_instance(cl), "cl argument must be oop");
    oop acl = loader;
    debug_only(jint loop_count = 0);
*** 4109,4151 ****
    return loader->obj_field(unnamedModule_offset);
  }
  
  // Caller needs ResourceMark.
  const char* java_lang_ClassLoader::describe_external(const oop loader) {
    if (loader == NULL) {
!     return "<bootstrap>";
    }
  
    bool well_known_loader = SystemDictionary::is_system_class_loader(loader) ||
                             SystemDictionary::is_platform_class_loader(loader);
  
-   const char* name = NULL;
-   oop nameOop = java_lang_ClassLoader::name(loader);
-   if (nameOop != NULL) {
-     name = java_lang_String::as_utf8_string(nameOop);
-   }
-   if (name == NULL) {
-     // Use placeholder for missing name to have fixed message format.
-     name = "<unnamed>";
-   }
- 
    stringStream ss;
!   ss.print("\"%s\" (instance of %s", name, loader->klass()->external_name());
    if (!well_known_loader) {
-     const char* parentName = NULL;
      oop pl = java_lang_ClassLoader::parent(loader);
      if (pl != NULL) {
!       oop parentNameOop = java_lang_ClassLoader::name(pl);
!       if (parentNameOop != NULL) {
!         parentName = java_lang_String::as_utf8_string(parentNameOop);
!       }
!       if (parentName == NULL) {
!         parentName = "<unnamed>";
!       }
!       ss.print(", child of \"%s\" %s", parentName, pl->klass()->external_name());
      } else {
!       ss.print(", child of <bootstrap>");
      }
    }
    ss.print(")");
  
    return ss.as_string();
--- 4124,4155 ----
    return loader->obj_field(unnamedModule_offset);
  }
  
  // Caller needs ResourceMark.
  const char* java_lang_ClassLoader::describe_external(const oop loader) {
+   ClassLoaderData *cld = ClassLoaderData::class_loader_data(loader);
+   const char* name = cld->loader_name_and_id();
+ 
+   // bootstrap loader
    if (loader == NULL) {
!     return name;
    }
  
    bool well_known_loader = SystemDictionary::is_system_class_loader(loader) ||
                             SystemDictionary::is_platform_class_loader(loader);
  
    stringStream ss;
!   ss.print("%s (instance of %s", name, loader->klass()->external_name());
    if (!well_known_loader) {
      oop pl = java_lang_ClassLoader::parent(loader);
+     ClassLoaderData *pl_cld = ClassLoaderData::class_loader_data(pl);
+     const char* parentName = pl_cld->loader_name_and_id();
      if (pl != NULL) {
!       ss.print(", child of %s %s", parentName, pl->klass()->external_name());
      } else {
!       // bootstrap loader
!       ss.print(", child of %s", parentName);
      }
    }
    ss.print(")");
  
    return ss.as_string();