1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package android.annotation;
17 
18 import java.lang.annotation.Retention;
19 import java.lang.annotation.Target;
20 
21 import static java.lang.annotation.ElementType.CONSTRUCTOR;
22 import static java.lang.annotation.ElementType.METHOD;
23 import static java.lang.annotation.ElementType.PARAMETER;
24 import static java.lang.annotation.ElementType.TYPE;
25 import static java.lang.annotation.RetentionPolicy.SOURCE;
26 
27 /**
28  * Denotes that the annotated method should only be called on a worker thread.
29  * If the annotated element is a class, then all methods in the class should be
30  * called on a worker thread.
31  * <p>
32  * Example:
33  *
34  * <pre>
35  * <code>
36  *  &#64;WorkerThread
37  *  protected abstract FilterResults performFiltering(CharSequence constraint);
38  * </code>
39  * </pre>
40  *
41  * @memberDoc This method may take several seconds to complete, so it should
42  *            only be called from a worker thread.
43  * @hide
44  */
45 @Retention(SOURCE)
46 @Target({METHOD,CONSTRUCTOR,TYPE,PARAMETER})
47 public @interface WorkerThread {
48 }
49