com.google.j2objc.annotations.RetainedLocalRef Maven / Gradle / Ivy
/*
* 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 com.google.j2objc.annotations;
import static java.lang.annotation.ElementType.LOCAL_VARIABLE;
import static java.lang.annotation.RetentionPolicy.SOURCE;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* Annotation that indicates a local variable should be retained outside of any
* subsequent AutoreleasePool use. Otherwise, if a local variable has a copy
* of an object in a container that is removed in an AutoreleasePool, it will
* be deallocated before the local variable goes out of scope.
*
* For example, a ThreadPoolExecutor is used to process a list of tasks,
* removing each task from the list as it is processed. ThreadPoolExecutor
* tasks are run inside of an AutoreleasePool, since these executors are often
* long-lived. If a local variable is initialized to one of the task list's
* elements, by default that variable won't be valid (will be deallocated)
* after task processing. Adding a LocalRetain annotation to the local
* variable ensures it is still valid after task processing.
*
* @author Tom Ball
*/
@Target(LOCAL_VARIABLE)
@Retention(SOURCE)
public @interface RetainedLocalRef {
}