1 /*
2  * Copyright (C) 2012 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 
17 package com.android.gallery3d.common;
18 
19 import android.os.AsyncTask;
20 import android.os.Build;
21 
22 import java.lang.reflect.InvocationTargetException;
23 import java.lang.reflect.Method;
24 import java.util.concurrent.Executor;
25 
26 /**
27  * Helper class to execute an AsyncTask in parallel if SDK version is 11 or newer.
28  */
29 public class AsyncTaskUtil {
30     private static Method sMethodExecuteOnExecutor;
31     private static Executor sExecutor;
32     static {
33         if (Build.VERSION.SDK_INT >= 11) {
34             try {
35                 sExecutor = (Executor) AsyncTask.class.getField("THREAD_POOL_EXECUTOR")
36                         .get(null);
37                 sMethodExecuteOnExecutor = AsyncTask.class.getMethod(
38                         "executeOnExecutor", Executor.class, Object[].class);
39             } catch (IllegalAccessException e) {
40                 throw new RuntimeException(e);
41             } catch (NoSuchFieldException e) {
42                 throw new RuntimeException(e);
43             } catch (NoSuchMethodException e) {
44                 throw new RuntimeException(e);
45             }
46         }
47     }
48 
executeInParallel(AsyncTask<Param, ?, ?> task, Param... params)49     public static <Param> void executeInParallel(AsyncTask<Param, ?, ?> task, Param... params) {
50         if (Build.VERSION.SDK_INT < 11) {
51             task.execute(params);
52         } else {
53             try {
54                 sMethodExecuteOnExecutor.invoke(task, sExecutor, params);
55             } catch (IllegalAccessException e) {
56                 throw new RuntimeException(e);
57             } catch (InvocationTargetException e) {
58                 throw new RuntimeException(e);
59             }
60         }
61     }
62 
AsyncTaskUtil()63     private AsyncTaskUtil() {
64     }
65 }
66 
67