DdmHandleThread.java revision 9066cfe9886ac131c34d59ed0e2d287b0e3c0087 
1/*
2 * Copyright (C) 2007 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
17package android.ddm;
18
19import org.apache.harmony.dalvik.ddmc.Chunk;
20import org.apache.harmony.dalvik.ddmc.ChunkHandler;
21import org.apache.harmony.dalvik.ddmc.DdmServer;
22import org.apache.harmony.dalvik.ddmc.DdmVmInternal;
23import android.util.Config;
24import android.util.Log;
25import java.nio.ByteBuffer;
26
27/**
28 * Handle thread-related traffic.
29 */
30public class DdmHandleThread extends ChunkHandler {
31
32    public static final int CHUNK_THEN = type("THEN");
33    public static final int CHUNK_THCR = type("THCR");
34    public static final int CHUNK_THDE = type("THDE");
35    public static final int CHUNK_THST = type("THST");
36    public static final int CHUNK_STKL = type("STKL");
37
38    private static DdmHandleThread mInstance = new DdmHandleThread();
39
40
41    /* singleton, do not instantiate */
42    private DdmHandleThread() {}
43
44    /**
45     * Register for the messages we're interested in.
46     */
47    public static void register() {
48        DdmServer.registerHandler(CHUNK_THEN, mInstance);
49        DdmServer.registerHandler(CHUNK_THST, mInstance);
50        DdmServer.registerHandler(CHUNK_STKL, mInstance);
51    }
52
53    /**
54     * Called when the DDM server connects.  The handler is allowed to
55     * send messages to the server.
56     */
57    public void connected() {}
58
59    /**
60     * Called when the DDM server disconnects.  Can be used to disable
61     * periodic transmissions or clean up saved state.
62     */
63    public void disconnected() {}
64
65    /**
66     * Handle a chunk of data.
67     */
68    public Chunk handleChunk(Chunk request) {
69        if (Config.LOGV)
70            Log.v("ddm-thread", "Handling " + name(request.type) + " chunk");
71        int type = request.type;
72
73        if (type == CHUNK_THEN) {
74            return handleTHEN(request);
75        } else if (type == CHUNK_THST) {
76            return handleTHST(request);
77        } else if (type == CHUNK_STKL) {
78            return handleSTKL(request);
79        } else {
80            throw new RuntimeException("Unknown packet "
81                + ChunkHandler.name(type));
82        }
83    }
84
85    /*
86     * Handle a "THread notification ENable" request.
87     */
88    private Chunk handleTHEN(Chunk request) {
89        ByteBuffer in = wrapChunk(request);
90
91        boolean enable = (in.get() != 0);
92        //Log.i("ddm-thread", "Thread notify enable: " + enable);
93
94        DdmVmInternal.threadNotify(enable);
95        return null;        // empty response
96    }
97
98    /*
99     * Handle a "THread STatus" request.  This is constructed by the VM.
100     */
101    private Chunk handleTHST(Chunk request) {
102        ByteBuffer in = wrapChunk(request);
103        // currently nothing to read from "in"
104
105        //Log.d("ddm-thread", "Thread status request");
106
107        byte[] status = DdmVmInternal.getThreadStats();
108        if (status != null)
109            return new Chunk(CHUNK_THST, status, 0, status.length);
110        else
111            return createFailChunk(1, "Can't build THST chunk");
112    }
113
114    /*
115     * Handle a STacK List request.
116     *
117     * This is done by threadId, which isn't great since those are
118     * recycled.  We need a thread serial ID.  The Linux tid is an okay
119     * answer as it's unlikely to recycle at the exact wrong moment.
120     * However, we're using the short threadId in THST messages, so we
121     * use them here for consistency.  (One thought is to keep the current
122     * thread ID in the low 16 bits and somehow serialize the top 16 bits.)
123     */
124    private Chunk handleSTKL(Chunk request) {
125        ByteBuffer in = wrapChunk(request);
126        int threadId;
127
128        threadId = in.getInt();
129
130        //Log.d("ddm-thread", "Stack list request " + threadId);
131
132        StackTraceElement[] trace = DdmVmInternal.getStackTraceById(threadId);
133        if (trace == null) {
134            return createFailChunk(1, "Stack trace unavailable");
135        } else {
136            return createStackChunk(trace, threadId);
137        }
138    }
139
140    /*
141     * Serialize a StackTraceElement[] into an STKL chunk.
142     *
143     * We include the threadId in the response so the other side doesn't have
144     * to match up requests and responses as carefully.
145     */
146    private Chunk createStackChunk(StackTraceElement[] trace, int threadId) {
147        int bufferSize = 0;
148
149        bufferSize += 4;            // version, flags, whatever
150        bufferSize += 4;            // thread ID
151        bufferSize += 4;            // frame count
152        for (StackTraceElement elem : trace) {
153            bufferSize += 4 + elem.getClassName().length() * 2;
154            bufferSize += 4 + elem.getMethodName().length() * 2;
155            bufferSize += 4;
156            if (elem.getFileName() != null)
157                bufferSize += elem.getFileName().length() * 2;
158            bufferSize += 4;        // line number
159        }
160
161        ByteBuffer out = ByteBuffer.allocate(bufferSize);
162        out.putInt(0);
163        out.putInt(threadId);
164        out.putInt(trace.length);
165        for (StackTraceElement elem : trace) {
166            out.putInt(elem.getClassName().length());
167            putString(out, elem.getClassName());
168            out.putInt(elem.getMethodName().length());
169            putString(out, elem.getMethodName());
170            if (elem.getFileName() != null) {
171                out.putInt(elem.getFileName().length());
172                putString(out, elem.getFileName());
173            } else {
174                out.putInt(0);
175            }
176            out.putInt(elem.getLineNumber());
177        }
178
179        return new Chunk(CHUNK_STKL, out);
180    }
181}
182
183