src/share/vm/prims/unsafe.cpp

rev 6604 : 6642881: Improve performance of Class.getClassLoader()
Summary: Add classLoader to java/lang/Class instance for fast access
Reviewed-by: alanb, lfoltan, rriggs, vlivanov, twisti, jfranck

*** 951,969 ****
      ThreadToNativeFromVM ttnfv(thread);
      return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
    }
  UNSAFE_END
  
  
  UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length))
    UnsafeWrapper("Unsafe_DefineClass");
    {
      ThreadToNativeFromVM ttnfv(thread);
  
      int depthFromDefineClass0 = 1;
      jclass  caller = JVM_GetCallerClass(env, depthFromDefineClass0);
!     jobject loader = (caller == NULL) ? NULL : JVM_GetClassLoader(env, caller);
      jobject pd     = (caller == NULL) ? NULL : JVM_GetProtectionDomain(env, caller);
  
      return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
    }
  UNSAFE_END
--- 951,977 ----
      ThreadToNativeFromVM ttnfv(thread);
      return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
    }
  UNSAFE_END
  
+ static jobject get_class_loader(JNIEnv* env, jclass cls) {
+   if (java_lang_Class::is_primitive(JNIHandles::resolve_non_null(cls))) {
+     return NULL;
+   }
+   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(cls));
+   oop loader = k->class_loader();
+   return JNIHandles::make_local(env, loader);
+ }
  
  UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length))
    UnsafeWrapper("Unsafe_DefineClass");
    {
      ThreadToNativeFromVM ttnfv(thread);
  
      int depthFromDefineClass0 = 1;
      jclass  caller = JVM_GetCallerClass(env, depthFromDefineClass0);
!     jobject loader = (caller == NULL) ? NULL : get_class_loader(env, caller);
      jobject pd     = (caller == NULL) ? NULL : JVM_GetProtectionDomain(env, caller);
  
      return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
    }
  UNSAFE_END