content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.ddm;
  
  import org.apache.harmony.dalvik.ddmc.Chunk;
  import org.apache.harmony.dalvik.ddmc.ChunkHandler;
  import org.apache.harmony.dalvik.ddmc.DdmServer;
  import org.apache.harmony.dalvik.ddmc.DdmVmInternal;
  import android.util.Log;
  import java.nio.ByteBuffer;
  
  /**
   * Handle thread-related traffic.
   */
  public class DdmHandleThread extends ChunkHandler {
  
      public static final int CHUNK_THEN = type("THEN");
      public static final int CHUNK_THCR = type("THCR");
      public static final int CHUNK_THDE = type("THDE");
      public static final int CHUNK_THST = type("THST");
      public static final int CHUNK_STKL = type("STKL");
  
      private static DdmHandleThread mInstance = new DdmHandleThread();
  
  
      /* singleton, do not instantiate */
      private DdmHandleThread() {}
  
      /**
       * Register for the messages we're interested in.
       */
      public static void register() {
          DdmServer.registerHandler(CHUNK_THEN, mInstance);
          DdmServer.registerHandler(CHUNK_THST, mInstance);
          DdmServer.registerHandler(CHUNK_STKL, mInstance);
      }
  
      /**
       * Called when the DDM server connects.  The handler is allowed to
       * send messages to the server.
       */
      public void connected() {}
  
      /**
       * Called when the DDM server disconnects.  Can be used to disable
       * periodic transmissions or clean up saved state.
       */
      public void disconnected() {}
  
      /**
       * Handle a chunk of data.
       */
      public Chunk handleChunk(Chunk request) {
          if (false)
              Log.v("ddm-thread", "Handling " + name(request.type) + " chunk");
          int type = request.type;
  
          if (type == CHUNK_THEN) {
              return handleTHEN(request);
          } else if (type == CHUNK_THST) {
              return handleTHST(request);
          } else if (type == CHUNK_STKL) {
              return handleSTKL(request);
          } else {
              throw new RuntimeException("Unknown packet "
                  + ChunkHandler.name(type));
          }
      }
  
      /*
       * Handle a "THread notification ENable" request.
       */
      private Chunk handleTHEN(Chunk request) {
          ByteBuffer in = wrapChunk(request);
  
          boolean enable = (in.get() != 0);
          //Log.i("ddm-thread", "Thread notify enable: " + enable);
  
          DdmVmInternal.threadNotify(enable);
          return null;        // empty response
      }
  
      /*
       * Handle a "THread STatus" request.  This is constructed by the VM.
       */
      private Chunk handleTHST(Chunk request) {
          ByteBuffer in = wrapChunk(request);
          // currently nothing to read from "in"
  
          //Log.d("ddm-thread", "Thread status request");
  
          byte[] status = DdmVmInternal.getThreadStats();
          if (status != null)
              return new Chunk(CHUNK_THST, status, 0, status.length);
          else
              return createFailChunk(1, "Can't build THST chunk");
      }
  
      /*
       * Handle a STacK List request.
       *
       * This is done by threadId, which isn't great since those are
       * recycled.  We need a thread serial ID.  The Linux tid is an okay
       * answer as it's unlikely to recycle at the exact wrong moment.
       * However, we're using the short threadId in THST messages, so we
       * use them here for consistency.  (One thought is to keep the current
       * thread ID in the low 16 bits and somehow serialize the top 16 bits.)
       */
      private Chunk handleSTKL(Chunk request) {
          ByteBuffer in = wrapChunk(request);
          int threadId;
  
          threadId = in.getInt();
  
          //Log.d("ddm-thread", "Stack list request " + threadId);
  
          StackTraceElement[] trace = DdmVmInternal.getStackTraceById(threadId);
          if (trace == null) {
              return createFailChunk(1, "Stack trace unavailable");
          } else {
              return createStackChunk(trace, threadId);
          }
      }
  
      /*
       * Serialize a StackTraceElement[] into an STKL chunk.
       *
       * We include the threadId in the response so the other side doesn't have
       * to match up requests and responses as carefully.
       */
      private Chunk createStackChunk(StackTraceElement[] trace, int threadId) {
          int bufferSize = 0;
  
          bufferSize += 4;            // version, flags, whatever
          bufferSize += 4;            // thread ID
          bufferSize += 4;            // frame count
          for (StackTraceElement elem : trace) {
              bufferSize += 4 + elem.getClassName().length() * 2;
              bufferSize += 4 + elem.getMethodName().length() * 2;
              bufferSize += 4;
              if (elem.getFileName() != null)
                  bufferSize += elem.getFileName().length() * 2;
              bufferSize += 4;        // line number
          }
  
          ByteBuffer out = ByteBuffer.allocate(bufferSize);
          out.putInt(0);
          out.putInt(threadId);
          out.putInt(trace.length);
          for (StackTraceElement elem : trace) {
              out.putInt(elem.getClassName().length());
              putString(out, elem.getClassName());
              out.putInt(elem.getMethodName().length());
              putString(out, elem.getMethodName());
              if (elem.getFileName() != null) {
                  out.putInt(elem.getFileName().length());
                  putString(out, elem.getFileName());
              } else {
                  out.putInt(0);
              }
              out.putInt(elem.getLineNumber());
          }
  
          return new Chunk(CHUNK_STKL, out);
      }
  }
  
  