Enhance AsyncChannel.
- Use Protocol for BASE of CMD's.
- Add synchronous connect methods.
- Back port sha1 c23971b3e4f92ac31996d4f9f32eef3cb4ef65fd from master
Change-Id: If0b3f6cbbb8d4268cad6ca19d26ab2ee42390d86
diff --git a/core/java/com/android/internal/util/AsyncChannel.java b/core/java/com/android/internal/util/AsyncChannel.java
index 101dd91..3973344 100644
--- a/core/java/com/android/internal/util/AsyncChannel.java
+++ b/core/java/com/android/internal/util/AsyncChannel.java
@@ -44,16 +44,16 @@
* In this usage model there is no need for the destination to
* use the connect methods. The typical sequence of operations is:</p>
*<ol>
- * <li>Client calls AsyncChannel#connect</li>
- * <li>Client receives CMD_CHANNEL_HALF_CONNECTED from AsyncChannel</li>
+ * <li>Client calls AsyncChannel#connectSync or Asynchronously:</li>
+ * <ol>For an asynchronous half connection client calls AsyncChannel#connect.</ol>
+ * <li>Client receives CMD_CHANNEL_HALF_CONNECTED from AsyncChannel</li>
+ * </ol>
* <li><code>comm-loop:</code></li>
- * <li>Client calls AsyncChannel#sendMessage(msgX)</li>
- * <li>Server receives and processes msgX</li>
- * <li>Server optionally calls AsyncChannel#replyToMessage(msgY)
- * and if sent Client receives and processes msgY</li>
+ * <li>Client calls AsyncChannel#sendMessage</li>
+ * <li>Server processes messages and optionally replies using AsyncChannel#replyToMessage
* <li>Loop to <code>comm-loop</code> until done</li>
- * <li>When done Client calls {@link AsyncChannel#disconnect(int)}</li>
- * <li>Client receives CMD_CHANNEL_DISCONNECTED from AsyncChannel</li>
+ * <li>When done Client calls {@link AsyncChannel#disconnect}</li>
+ * <li>Client/Server receives CMD_CHANNEL_DISCONNECTED from AsyncChannel</li>
*</ol>
*<br/>
* <p>A second usage model is where the server/destination needs to know
@@ -62,21 +62,26 @@
* different state for each client. In this model the server will also
* use the connect methods. The typical sequence of operation is:</p>
*<ol>
- * <li>Client calls AsyncChannel#connect</li>
- * <li>Client receives CMD_CHANNEL_HALF_CONNECTED from AsyncChannel</li>
- * <li>Client calls AsyncChannel#sendMessage(CMD_CHANNEL_FULL_CONNECTION)</li>
+ * <li>Client calls AsyncChannel#fullyConnectSync or Asynchronously:<li>
+ * <ol>For an asynchronous full connection it calls AsyncChannel#connect</li>
+ * <li>Client receives CMD_CHANNEL_HALF_CONNECTED from AsyncChannel</li>
+ * <li>Client calls AsyncChannel#sendMessage(CMD_CHANNEL_FULL_CONNECTION)</li>
+ * </ol>
* <li>Server receives CMD_CHANNEL_FULL_CONNECTION</li>
- * <li>Server calls AsyncChannel#connect</li>
- * <li>Server receives CMD_CHANNEL_HALF_CONNECTED from AsyncChannel</li>
+ * <li>Server calls AsyncChannel#connected</li>
* <li>Server sends AsyncChannel#sendMessage(CMD_CHANNEL_FULLY_CONNECTED)</li>
* <li>Client receives CMD_CHANNEL_FULLY_CONNECTED</li>
* <li><code>comm-loop:</code></li>
* <li>Client/Server uses AsyncChannel#sendMessage/replyToMessage
* to communicate and perform work</li>
* <li>Loop to <code>comm-loop</code> until done</li>
- * <li>When done Client/Server calls {@link AsyncChannel#disconnect(int)}</li>
+ * <li>When done Client/Server calls {@link AsyncChannel#disconnect}</li>
* <li>Client/Server receives CMD_CHANNEL_DISCONNECTED from AsyncChannel</li>
*</ol>
+ *
+ * TODO: Consider simplifying where we have connect and fullyConnect with only one response
+ * message RSP_CHANNEL_CONNECT instead of two, CMD_CHANNEL_HALF_CONNECTED and
+ * CMD_CHANNEL_FULLY_CONNECTED. We'd also change CMD_CHANNEL_FULL_CONNECTION to REQ_CHANNEL_CONNECT.
*/
public class AsyncChannel {
/** Log tag */
@@ -85,6 +90,8 @@
/** Enable to turn on debugging */
private static final boolean DBG = false;
+ private static final int BASE = Protocol.BASE_SYSTEM_ASYNC_CHANNEL;
+
/**
* Command sent when the channel is half connected. Half connected
* means that the channel can be used to send commends to the destination
@@ -98,7 +105,7 @@
* msg.obj == the AsyncChannel
* msg.replyTo == dstMessenger if successful
*/
- public static final int CMD_CHANNEL_HALF_CONNECTED = -1;
+ public static final int CMD_CHANNEL_HALF_CONNECTED = BASE + 0;
/**
* Command typically sent when after receiving the CMD_CHANNEL_HALF_CONNECTED.
@@ -107,7 +114,7 @@
*
* msg.replyTo = srcMessenger.
*/
- public static final int CMD_CHANNEL_FULL_CONNECTION = -2;
+ public static final int CMD_CHANNEL_FULL_CONNECTION = BASE + 1;
/**
* Command typically sent after the destination receives a CMD_CHANNEL_FULL_CONNECTION.
@@ -115,31 +122,33 @@
*
* msg.arg1 == 0 : Accept connection
* : All other values signify the destination rejected the connection
- * and {@link AsyncChannel#disconnect(int)} would typically be called.
+ * and {@link AsyncChannel#disconnect} would typically be called.
*/
- public static final int CMD_CHANNEL_FULLY_CONNECTED = -3;
+ public static final int CMD_CHANNEL_FULLY_CONNECTED = BASE + 2;
/**
* Command sent when one side or the other wishes to disconnect. The sender
* may or may not be able to receive a reply depending upon the protocol and
- * the state of the connection. The receiver should call {@link AsyncChannel#disconnect(int)}
+ * the state of the connection. The receiver should call {@link AsyncChannel#disconnect}
* to close its side of the channel and it will receive a CMD_CHANNEL_DISCONNECTED
* when the channel is closed.
*
* msg.replyTo = messenger that is disconnecting
*/
- public static final int CMD_CHANNEL_DISCONNECT = -4;
+ public static final int CMD_CHANNEL_DISCONNECT = BASE + 3;
/**
* Command sent when the channel becomes disconnected. This is sent when the
* channel is forcibly disconnected by the system or as a reply to CMD_CHANNEL_DISCONNECT.
*
* msg.arg1 == 0 : STATUS_SUCCESSFUL
+ * 1 : STATUS_BINDING_UNSUCCESSFUL
+ * 2 : STATUS_SEND_UNSUCCESSFUL
* : All other values signify failure and the channel state is indeterminate
* msg.obj == the AsyncChannel
* msg.replyTo = messenger disconnecting or null if it was never connected.
*/
- public static final int CMD_CHANNEL_DISCONNECTED = -5;
+ public static final int CMD_CHANNEL_DISCONNECTED = BASE + 4;
/** Successful status always 0, !0 is an unsuccessful status */
public static final int STATUS_SUCCESSFUL = 0;
@@ -147,6 +156,12 @@
/** Error attempting to bind on a connect */
public static final int STATUS_BINDING_UNSUCCESSFUL = 1;
+ /** Error attempting to send a message */
+ public static final int STATUS_SEND_UNSUCCESSFUL = 2;
+
+ /** CMD_FULLY_CONNECTED refused because a connection already exists*/
+ public static final int STATUS_FULL_CONNECTION_REFUSED_ALREADY_CONNECTED = 3;
+
/** Service connection */
private AsyncChannelConnection mConnection;
@@ -169,9 +184,7 @@
}
/**
- * Connect handler to named package/class.
- *
- * Sends a CMD_CHANNEL_HALF_CONNECTED message to srcHandler when complete.
+ * Connect handler to named package/class synchronously.
*
* @param srcContext is the context of the source
* @param srcHandler is the hander to receive CONNECTED & DISCONNECTED
@@ -179,8 +192,10 @@
* @param dstPackageName is the destination package name
* @param dstClassName is the fully qualified class name (i.e. contains
* package name)
+ *
+ * @return STATUS_SUCCESSFUL on success any other value is an error.
*/
- private void connectSrcHandlerToPackage(
+ public int connectSrcHandlerToPackageSync(
Context srcContext, Handler srcHandler, String dstPackageName, String dstClassName) {
if (DBG) log("connect srcHandler to dst Package & class E");
@@ -202,11 +217,61 @@
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setClassName(dstPackageName, dstClassName);
boolean result = srcContext.bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
- if (!result) {
- replyHalfConnected(STATUS_BINDING_UNSUCCESSFUL);
- }
-
if (DBG) log("connect srcHandler to dst Package & class X result=" + result);
+ return result ? STATUS_SUCCESSFUL : STATUS_BINDING_UNSUCCESSFUL;
+ }
+
+ /**
+ * Connect a handler to Messenger synchronously.
+ *
+ * @param srcContext is the context of the source
+ * @param srcHandler is the hander to receive CONNECTED & DISCONNECTED
+ * messages
+ * @param dstMessenger is the hander to send messages to.
+ *
+ * @return STATUS_SUCCESSFUL on success any other value is an error.
+ */
+ public int connectSync(Context srcContext, Handler srcHandler, Messenger dstMessenger) {
+ if (DBG) log("halfConnectSync srcHandler to the dstMessenger E");
+
+ // We are connected
+ connected(srcContext, srcHandler, dstMessenger);
+
+ if (DBG) log("halfConnectSync srcHandler to the dstMessenger X");
+ return STATUS_SUCCESSFUL;
+ }
+
+ /**
+ * connect two local Handlers synchronously.
+ *
+ * @param srcContext is the context of the source
+ * @param srcHandler is the hander to receive CONNECTED & DISCONNECTED
+ * messages
+ * @param dstHandler is the hander to send messages to.
+ *
+ * @return STATUS_SUCCESSFUL on success any other value is an error.
+ */
+ public int connectSync(Context srcContext, Handler srcHandler, Handler dstHandler) {
+ return connectSync(srcContext, srcHandler, new Messenger(dstHandler));
+ }
+
+ /**
+ * Fully connect two local Handlers synchronously.
+ *
+ * @param srcContext is the context of the source
+ * @param srcHandler is the hander to receive CONNECTED & DISCONNECTED
+ * messages
+ * @param dstHandler is the hander to send messages to.
+ *
+ * @return STATUS_SUCCESSFUL on success any other value is an error.
+ */
+ public int fullyConnectSync(Context srcContext, Handler srcHandler, Handler dstHandler) {
+ int status = connectSync(srcContext, srcHandler, dstHandler);
+ if (status == STATUS_SUCCESSFUL) {
+ Message response = sendMessageSynchronously(CMD_CHANNEL_FULL_CONNECTION);
+ status = response.arg1;
+ }
+ return status;
}
/**
@@ -241,8 +306,11 @@
mDstClassName = dstClassName;
}
+ @Override
public void run() {
- connectSrcHandlerToPackage(mSrcCtx, mSrcHdlr, mDstPackageName, mDstClassName);
+ int result = connectSrcHandlerToPackageSync(mSrcCtx, mSrcHdlr, mDstPackageName,
+ mDstClassName);
+ replyHalfConnected(result);
}
}
@@ -281,15 +349,8 @@
public void connect(Context srcContext, Handler srcHandler, Messenger dstMessenger) {
if (DBG) log("connect srcHandler to the dstMessenger E");
- // Initialize source fields
- mSrcContext = srcContext;
- mSrcHandler = srcHandler;
- mSrcMessenger = new Messenger(mSrcHandler);
-
- // Initialize destination fields
- mDstMessenger = dstMessenger;
-
- if (DBG) log("tell source we are half connected");
+ // We are connected
+ connected(srcContext, srcHandler, dstMessenger);
// Tell source we are half connected
replyHalfConnected(STATUS_SUCCESSFUL);
@@ -298,11 +359,31 @@
}
/**
- * Connect two local Handlers.
+ * Connect handler to messenger. This method is typically called
+ * when a server receives a CMD_CHANNEL_FULL_CONNECTION request
+ * and initializes the internal instance variables to allow communication
+ * with the dstMessenger.
*
- * Sends a CMD_CHANNEL_HALF_CONNECTED message to srcHandler when complete.
- * msg.arg1 = status
- * msg.obj = the AsyncChannel
+ * @param srcContext
+ * @param srcHandler
+ * @param dstMessenger
+ */
+ public void connected(Context srcContext, Handler srcHandler, Messenger dstMessenger) {
+ if (DBG) log("connected srcHandler to the dstMessenger E");
+
+ // Initialize source fields
+ mSrcContext = srcContext;
+ mSrcHandler = srcHandler;
+ mSrcMessenger = new Messenger(mSrcHandler);
+
+ // Initialize destination fields
+ mDstMessenger = dstMessenger;
+
+ if (DBG) log("connected srcHandler to the dstMessenger X");
+ }
+
+ /**
+ * Connect two local Handlers.
*
* @param srcContext is the context of the source
* @param srcHandler is the hander to receive CONNECTED & DISCONNECTED
@@ -331,6 +412,7 @@
* To close the connection call when handler receives CMD_CHANNEL_DISCONNECTED
*/
public void disconnected() {
+ mSrcContext = null;
mSrcHandler = null;
mSrcMessenger = null;
mDstMessenger = null;
@@ -341,15 +423,11 @@
* Disconnect
*/
public void disconnect() {
- if (mConnection != null) {
+ if ((mConnection != null) && (mSrcContext != null)) {
mSrcContext.unbindService(mConnection);
}
if (mSrcHandler != null) {
- Message msg = mSrcHandler.obtainMessage(CMD_CHANNEL_DISCONNECTED);
- msg.arg1 = STATUS_SUCCESSFUL;
- msg.obj = this;
- msg.replyTo = mDstMessenger;
- mSrcHandler.sendMessage(msg);
+ replyDisconnected(STATUS_SUCCESSFUL);
}
}
@@ -363,7 +441,7 @@
try {
mDstMessenger.send(msg);
} catch (RemoteException e) {
- log("TODO: handle sendMessage RemoteException" + e);
+ replyDisconnected(STATUS_SEND_UNSUCCESSFUL);
}
}
@@ -444,6 +522,7 @@
*/
public void replyToMessage(Message srcMsg, Message dstMsg) {
try {
+ dstMsg.replyTo = mSrcMessenger;
srcMsg.replyTo.send(dstMsg);
} catch (RemoteException e) {
log("TODO: handle replyToMessage RemoteException" + e);
@@ -694,10 +773,14 @@
private static Message sendMessageSynchronously(Messenger dstMessenger, Message msg) {
SyncMessenger sm = SyncMessenger.obtain();
try {
- msg.replyTo = sm.mMessenger;
- dstMessenger.send(msg);
- synchronized (sm.mHandler.mLockObject) {
- sm.mHandler.mLockObject.wait();
+ if (dstMessenger != null && msg != null) {
+ msg.replyTo = sm.mMessenger;
+ synchronized (sm.mHandler.mLockObject) {
+ dstMessenger.send(msg);
+ sm.mHandler.mLockObject.wait();
+ }
+ } else {
+ sm.mHandler.mResultMsg = null;
}
} catch (InterruptedException e) {
sm.mHandler.mResultMsg = null;
@@ -712,6 +795,7 @@
/**
* Reply to the src handler that we're half connected.
+ * see: CMD_CHANNEL_HALF_CONNECTED for message contents
*
* @param status to be stored in msg.arg1
*/
@@ -724,23 +808,36 @@
}
/**
+ * Reply to the src handler that we are disconnected
+ * see: CMD_CHANNEL_DISCONNECTED for message contents
+ *
+ * @param status to be stored in msg.arg1
+ */
+ private void replyDisconnected(int status) {
+ Message msg = mSrcHandler.obtainMessage(CMD_CHANNEL_DISCONNECTED);
+ msg.arg1 = status;
+ msg.obj = this;
+ msg.replyTo = mDstMessenger;
+ mSrcHandler.sendMessage(msg);
+ }
+
+
+ /**
* ServiceConnection to receive call backs.
*/
class AsyncChannelConnection implements ServiceConnection {
AsyncChannelConnection() {
}
+ @Override
public void onServiceConnected(ComponentName className, IBinder service) {
mDstMessenger = new Messenger(service);
replyHalfConnected(STATUS_SUCCESSFUL);
}
+ @Override
public void onServiceDisconnected(ComponentName className) {
- Message msg = mSrcHandler.obtainMessage(CMD_CHANNEL_DISCONNECTED);
- msg.arg1 = STATUS_SUCCESSFUL;
- msg.obj = AsyncChannel.this;
- msg.replyTo = mDstMessenger;
- mSrcHandler.sendMessage(msg);
+ replyDisconnected(STATUS_SUCCESSFUL);
}
}
diff --git a/core/java/com/android/internal/util/Protocol.java b/core/java/com/android/internal/util/Protocol.java
index 2689f09..b35f615 100644
--- a/core/java/com/android/internal/util/Protocol.java
+++ b/core/java/com/android/internal/util/Protocol.java
@@ -29,9 +29,17 @@
* {@hide}
*/
public class Protocol {
- public static final int MAX_MESSAGE = 0x0000FFFF;
+ public static final int MAX_MESSAGE = 0x0000FFFF;
- public static final int BASE_WIFI = 0x00010000;
- public static final int BASE_DHCP = 0x00020000;
+ /** Base reserved for system */
+ public static final int BASE_SYSTEM_RESERVED = 0x00010000;
+ public static final int BASE_SYSTEM_ASYNC_CHANNEL = 0x00011000;
+
+ /** Non system protocols */
+ public static final int BASE_WIFI = 0x00020000;
+ public static final int BASE_DHCP = 0x00030000;
+ public static final int BASE_DATA_CONNECTION = 0x00040000;
+ public static final int BASE_DATA_CONNECTION_TRACKER = 0x00050000;
+
//TODO: define all used protocols
}