jnr.ffi.annotations.Clear Maven / Gradle / Ivy
/*
* Copyright (C) 2008-2010 Wayne Meissner
*
* This file is part of the JNR project.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jnr.ffi.annotations;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that the temporary native memory allocated for an {@code @Out} paramneter
* should be cleared before passing to the native function.
*
* By default, parameters that are annotated as {@code @Out} only do not clear
* the data in the temporary native memory area allocated when a java heap object
* is passed in as the parameter, so the memory passed to the native function is
* full of garbage data. After the native method returns, the native memory is
* copied back to java, which is usually not a problem, since the native function
* will have updated the memory with valid data. However, if the native function
* fails, the garbage data that was in the temporary native memory will be copied
* back to java.
*
* @see In
* @see Out
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.PARAMETER, ElementType.ANNOTATION_TYPE })
public @interface Clear {
}