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 
17 import java.io.File;
18 import java.io.IOException;
19 import java.lang.reflect.Method;
20 
21 /**
22  * Controls deoptimization using dalvik.system.VMDebug class.
23  */
24 public class DeoptimizationController {
createTempFile()25   private static File createTempFile() throws Exception {
26     try {
27       return  File.createTempFile("test", ".trace");
28     } catch (IOException e) {
29       System.setProperty("java.io.tmpdir", "/data/local/tmp");
30       try {
31         return File.createTempFile("test", ".trace");
32       } catch (IOException e2) {
33         System.setProperty("java.io.tmpdir", "/sdcard");
34         return File.createTempFile("test", ".trace");
35       }
36     }
37   }
38 
startDeoptimization()39   public static void startDeoptimization() {
40     try {
41       File tempFile = createTempFile();
42       tempFile.deleteOnExit();
43       String tempFileName = tempFile.getPath();
44 
45       VMDebug.startMethodTracing(tempFileName, 0, 0, false, 1000);
46       if (VMDebug.getMethodTracingMode() == 0) {
47         throw new IllegalStateException("Not tracing.");
48       }
49     } catch (Exception exc) {
50       exc.printStackTrace(System.err);
51     }
52   }
53 
stopDeoptimization()54   public static void stopDeoptimization() {
55     try {
56       VMDebug.stopMethodTracing();
57       if (VMDebug.getMethodTracingMode() != 0) {
58         throw new IllegalStateException("Still tracing.");
59       }
60     } catch (Exception exc) {
61       exc.printStackTrace(System.err);
62     }
63   }
64 
65   private static class VMDebug {
66     private static final Method startMethodTracingMethod;
67     private static final Method stopMethodTracingMethod;
68     private static final Method getMethodTracingModeMethod;
69 
70     static {
71       try {
72         Class<?> c = Class.forName("dalvik.system.VMDebug");
73         startMethodTracingMethod = c.getDeclaredMethod("startMethodTracing", String.class,
74             Integer.TYPE, Integer.TYPE, Boolean.TYPE, Integer.TYPE);
75         stopMethodTracingMethod = c.getDeclaredMethod("stopMethodTracing");
76         getMethodTracingModeMethod = c.getDeclaredMethod("getMethodTracingMode");
77       } catch (Exception e) {
78         throw new RuntimeException(e);
79       }
80     }
81 
startMethodTracing(String filename, int bufferSize, int flags, boolean samplingEnabled, int intervalUs)82     public static void startMethodTracing(String filename, int bufferSize, int flags,
83         boolean samplingEnabled, int intervalUs) throws Exception {
84       startMethodTracingMethod.invoke(null, filename, bufferSize, flags, samplingEnabled,
85           intervalUs);
86     }
stopMethodTracing()87     public static void stopMethodTracing() throws Exception {
88       stopMethodTracingMethod.invoke(null);
89     }
getMethodTracingMode()90     public static int getMethodTracingMode() throws Exception {
91       return (int) getMethodTracingModeMethod.invoke(null);
92     }
93   }
94 }
95