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 {
25   private static final String TEMP_FILE_NAME_PREFIX = "test";
26   private static final String TEMP_FILE_NAME_SUFFIX = ".trace";
27 
createTempFile()28   private static File createTempFile() throws Exception {
29     try {
30       return  File.createTempFile(TEMP_FILE_NAME_PREFIX, TEMP_FILE_NAME_SUFFIX);
31     } catch (IOException e) {
32       System.setProperty("java.io.tmpdir", "/data/local/tmp");
33       try {
34         return File.createTempFile(TEMP_FILE_NAME_PREFIX, TEMP_FILE_NAME_SUFFIX);
35       } catch (IOException e2) {
36         System.setProperty("java.io.tmpdir", "/sdcard");
37         return File.createTempFile(TEMP_FILE_NAME_PREFIX, TEMP_FILE_NAME_SUFFIX);
38       }
39     }
40   }
41 
startDeoptimization()42   public static void startDeoptimization() {
43     File tempFile = null;
44     try {
45       tempFile = createTempFile();
46       String tempFileName = tempFile.getPath();
47 
48       VMDebug.startMethodTracing(tempFileName, 0, 0, false, 1000);
49       if (VMDebug.getMethodTracingMode() == 0) {
50         throw new IllegalStateException("Not tracing.");
51       }
52     } catch (Exception exc) {
53       exc.printStackTrace(System.err);
54     } finally {
55       if (tempFile != null) {
56         tempFile.delete();
57       }
58     }
59   }
60 
stopDeoptimization()61   public static void stopDeoptimization() {
62     try {
63       VMDebug.stopMethodTracing();
64       if (VMDebug.getMethodTracingMode() != 0) {
65         throw new IllegalStateException("Still tracing.");
66       }
67     } catch (Exception exc) {
68       exc.printStackTrace(System.err);
69     }
70   }
71 
72   private static class VMDebug {
73     private static final Method startMethodTracingMethod;
74     private static final Method stopMethodTracingMethod;
75     private static final Method getMethodTracingModeMethod;
76 
77     static {
78       try {
79         Class<?> c = Class.forName("dalvik.system.VMDebug");
80         startMethodTracingMethod = c.getDeclaredMethod("startMethodTracing", String.class,
81             Integer.TYPE, Integer.TYPE, Boolean.TYPE, Integer.TYPE);
82         stopMethodTracingMethod = c.getDeclaredMethod("stopMethodTracing");
83         getMethodTracingModeMethod = c.getDeclaredMethod("getMethodTracingMode");
84       } catch (Exception e) {
85         throw new RuntimeException(e);
86       }
87     }
88 
startMethodTracing(String filename, int bufferSize, int flags, boolean samplingEnabled, int intervalUs)89     public static void startMethodTracing(String filename, int bufferSize, int flags,
90         boolean samplingEnabled, int intervalUs) throws Exception {
91       startMethodTracingMethod.invoke(null, filename, bufferSize, flags, samplingEnabled,
92           intervalUs);
93     }
stopMethodTracing()94     public static void stopMethodTracing() throws Exception {
95       stopMethodTracingMethod.invoke(null);
96     }
getMethodTracingMode()97     public static int getMethodTracingMode() throws Exception {
98       return (int) getMethodTracingModeMethod.invoke(null);
99     }
100   }
101 }
102