From 97f0eebea14af9d34d57370984c88a5066183e1b Mon Sep 17 00:00:00 2001
From: Lyubomir Marinov <lyubomir.marinov@jitsi.org>
Date: Tue, 28 Oct 2014 09:42:33 +0200
Subject: [PATCH] Clarifies, simplifies the source code, reduces the field
access.
---
src/org/jitsi/sctp4j/SctpSocket.java | 125 ++++++++++++++-------------
1 file changed, 64 insertions(+), 61 deletions(-)
diff --git a/src/org/jitsi/sctp4j/SctpSocket.java b/src/org/jitsi/sctp4j/SctpSocket.java
index 690b78d4..14a49797 100644
--- a/src/org/jitsi/sctp4j/SctpSocket.java
+++ b/src/org/jitsi/sctp4j/SctpSocket.java
@@ -24,16 +24,6 @@ public class SctpSocket
*/
private final static Logger logger = Logger.getLogger(SctpSocket.class);
- /**
- * Reader access synchronization lock to the native socket pointer.
- */
- private final Lock rl;
-
- /**
- * Writer access synchronization lock to the native socket pointer.
- */
- private final Lock wl;
-
/**
* Reads 32 bit unsigned int from the buffer at specified offset
*
@@ -212,7 +202,7 @@ public static void debugSctpPacket(byte[] packet, String id)
/**
* Local SCTP port.
*/
- final int localPort;
+ private final int localPort;
/**
* SCTP notification listener.
@@ -234,13 +224,24 @@ public void onSctpNotification(
}
};
+ /**
+ * Reader access synchronization lock to the native socket pointer.
+ */
+ private final Lock rl;
+
/**
* Pointer to native socket counterpart.
*/
- long socketPtr;
+ private long socketPtr;
+
+ /**
+ * Writer access synchronization lock to the native socket pointer.
+ */
+ private final Lock wl;
/**
* Creates new instance of <tt>SctpSocket</tt>.
+ *
* @param socketPtr native socket pointer.
* @param localPort local SCTP port on which this socket is bound.
*/
@@ -282,12 +283,12 @@ public void onSctpNotification(
// 5. a combination of the above
// 6. change the synchronization scheme
//
- // However, usrsctp seems to already be queueing packets and having
+ // However, usrsctp seems to already be queuing packets and having
// sending/processing threads so there's no need to duplicate this
// functionality here. We implement a readers-writers scheme that
// protects the native socket pointer instead.
+ ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(true);
- final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock(true);
this.wl = rwl.writeLock();
this.rl = rwl.readLock();
}
@@ -307,9 +308,7 @@ public boolean accept()
rl.lock();
try
{
- checkIsPointerValid();
-
- return Sctp.usrsctp_accept(socketPtr);
+ return Sctp.usrsctp_accept(assertSocketPtr());
}
finally
{
@@ -318,18 +317,21 @@ public boolean accept()
}
/**
- * Checks if {@link #socketPtr} is not null. Otherwise throws
- * <tt>IOException</tt>.
+ * Throws an <tt>IOException</tt> if {@link #socketPtr} equals <tt>0</tt>;
+ * otherwise, returns <tt>socketPtr</tt>s.
*
- * @throws IOException in case this socket pointer is invalid.
+ * @return <tt>socketPtr</tt> if it is not <tt>0</tt>
+ * @throws IOException if <tt>socketPtr</tt> is <tt>0</tt>
*/
- private void checkIsPointerValid()
+ private long assertSocketPtr()
throws IOException
{
- if(socketPtr == 0)
- {
- throw new IOException("Socket is closed");
- }
+ long socketPtr = this.socketPtr;
+
+ if (socketPtr == 0)
+ throw new IOException("SctpSocket is closed");
+ else
+ return socketPtr;
}
/**
@@ -346,8 +348,8 @@ public void close()
wl.lock();
try
{
- // Recheck state because another thread might have
- // acquired write lock and changed state before we did.
+ // Recheck state because another thread might have acquired the
+ // write lock and changed the state before we did.
if (socketPtr != 0)
{
Sctp.closeSocket(socketPtr);
@@ -367,9 +369,10 @@ public void close()
/**
* Initializes SCTP connection by sending INIT message.
+ *
* @param remotePort remote SCTP port.
* @throws java.io.IOException if this socket is closed or an error occurs
- * while trying to connect the socket.
+ * while trying to connect the socket.
*/
public void connect(int remotePort)
throws IOException
@@ -377,12 +380,8 @@ public void connect(int remotePort)
rl.lock();
try
{
- checkIsPointerValid();
-
- if (!Sctp.usrsctp_connect(socketPtr, remotePort))
- {
+ if (!Sctp.usrsctp_connect(assertSocketPtr(), remotePort))
throw new IOException("Failed to connect SCTP");
- }
}
finally
{
@@ -392,6 +391,7 @@ public void connect(int remotePort)
/**
* Returns SCTP port used by this socket.
+ *
* @return SCTP port used by this socket.
*/
public int getPort()
@@ -406,12 +406,9 @@ public void listen()
throws IOException
{
rl.lock();
-
try
{
- checkIsPointerValid();
-
- Sctp.usrsctp_listen(socketPtr);
+ Sctp.usrsctp_listen(assertSocketPtr());
}
finally
{
@@ -421,6 +418,7 @@ public void listen()
/**
* Call this method to pass network packets received on the link.
+ *
* @param packet network packet received.
* @param offset the position in the packet buffer where actual data starts
* @param len length of packet data in the buffer.
@@ -438,15 +436,9 @@ public void onConnIn(byte[] packet, int offset, int len)
}
rl.lock();
-
try
{
- // Prevent JVM crash by throwing IOException
- checkIsPointerValid();
-
- //debugSctpPacket(packet);
-
- Sctp.onConnIn(socketPtr, packet, offset, len);
+ Sctp.onConnIn(assertSocketPtr(), packet, offset, len);
}
finally
{
@@ -456,6 +448,7 @@ public void onConnIn(byte[] packet, int offset, int len)
/**
* Fired when usrsctp stack sends notification.
+ *
* @param notification the <tt>SctpNotification</tt> triggered.
*/
private void onNotification(SctpNotification notification)
@@ -511,10 +504,11 @@ void onSctpInboundPacket(byte[] data, int sid, int ssn, int tsn, long ppid,
onSctpIn(data, sid, ssn, tsn, ppid, context, flags);
}
}
-
+
/**
- * Callback triggered by Sctp stack whenever it wants to send some
- * network packet.
+ * Callback triggered by Sctp stack whenever it wants to send some network
+ * packet.
+ *
* @param packet network packet buffer.
* @param tos type of service???
* @param set_df use IP don't fragment option
@@ -545,6 +539,7 @@ int onSctpOut(byte[] packet, int tos, int set_df)
/**
* Sends given <tt>data</tt> on selected SCTP stream using given payload
* protocol identifier.
+ *
* @param data the data to send.
* @param ordered should we care about message order ?
* @param sid SCTP stream identifier
@@ -556,20 +551,23 @@ public int send(byte[] data, boolean ordered, int sid, int ppid)
{
return send(data, 0, data.length, ordered, sid, ppid);
}
-
+
/**
* Sends given <tt>data</tt> on selected SCTP stream using given payload
* protocol identifier.
+ *
* @param data the data to send.
- * @param offset postion of the data inside the buffer
+ * @param offset position of the data inside the buffer
* @param len data length
* @param ordered should we care about message order ?
* @param sid SCTP stream identifier
* @param ppid payload protocol identifier
* @return sent bytes count or <tt>-1</tt> in case of an error.
*/
- public int send(byte[] data, int offset, int len,
- boolean ordered, int sid, int ppid)
+ public int send(
+ byte[] data, int offset, int len,
+ boolean ordered,
+ int sid, int ppid)
throws IOException
{
if(data == null)
@@ -584,21 +582,24 @@ public int send(byte[] data, int offset, int len,
rl.lock();
try
{
- // Prevent JVM crash by throwing IOException
- checkIsPointerValid();
-
- return Sctp.usrsctp_send(
- socketPtr, data, offset, len, ordered, sid, ppid);
+ return
+ Sctp.usrsctp_send(
+ assertSocketPtr(),
+ data, offset, len,
+ ordered,
+ sid, ppid);
}
finally
{
rl.unlock();
}
}
+
/**
* Sets the callback that will be fired when new data is received.
- * @param callback the callback that will be fired when new data
- * is received.
+ *
+ * @param callback the callback that will be fired when new data is
+ * received.
*/
public void setDataCallback(SctpDataCallback callback)
{
@@ -607,8 +608,9 @@ public void setDataCallback(SctpDataCallback callback)
/**
* Sets the link that will be used to send network packets.
+ *
* @param link <tt>NetworkLink</tt> that will be used by this instance to
- * send network packets.
+ * send network packets.
*/
public void setLink(NetworkLink link)
{
@@ -617,6 +619,7 @@ public void setLink(NetworkLink link)
/**
* Sets the listener that will be notified about SCTP event.
+ *
* @param l the {@link NotificationListener} to set.
*/
public void setNotificationListener(NotificationListener l)
@@ -631,11 +634,11 @@ public interface NotificationListener
{
/**
* Fired when usrsctp stack sends notification.
+ *
* @param socket the {@link SctpSocket} notification source.
* @param notification the <tt>SctpNotification</tt> triggered.
*/
- void onSctpNotification(
- SctpSocket socket,
+ void onSctpNotification( SctpSocket socket,
SctpNotification notification);
}
}
--
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