分布式-通信框架什么是RPC来个手写RPC框架show一波吧

139 阅读 0 评论 92 点赞

我是靠谱客的博主花痴鲜花，这篇文章主要介绍分布式-通信框架什么是RPC来个手写RPC框架show一波吧，现在分享给大家，希望可以做个参考。

什么是RPC

了解Java RMI

Java RMI代码实践

JavaRMI源码分析

远程对象发布-类图

远程引用层-类图

源码解读

发布远程对象

来个手写RPC框架show一波吧

什么是RPC

RPC(Remote Procedure Call，远程过程调用)，一般用来实现部署在不同机器上的系统之间的方法调用，使得程序能够像访问本地系统资源一样，通过网络传输去访问远端系统资源；对于客户端来说，传输层用什么协议，序列化、反序列化都是透明的。

了解Java RMI

RMI全称是Remote Method Invovation远程方法调用，一种用于远程过程调用的应用程序编程接口，是纯Java的网络分布式应用系统的核心解决方案之一。

RMI目前使用Java远程消息交换协议JRMP(Java Remote Messageing Protocol)进行通信，由于JRMP是专为Java对象制定的，是分布式应用系统的百分之百纯Java解决方案，用Java RMI开发的应用系统可以部署在任何支持JRE的平台上，缺点是，由于JRMP是专门为Java对象指定的，因此RMI对于非Java语言开发的应用系统的支持不足，不能与非Java语言书写的对象进行通信

Java RMI代码实践

远程对象必须实现UnicastRemoteObject，这样才能保证客户端访问获得远程对象时，该远程对象会把自身的一个拷贝以Socket形式传输给客户端，客户端获得的拷贝称为“stub”，而服务器端本身已经存在的远程对象称为“skeleton”，此时客户端的stub是客户端的一个代理，用于与服务器端进行通信，而skeleton是服务器端的一个代理，用于接收客户端的请求之后调用远程方法来相应客户端的请求

JavaRMI源码分析

这里以RMI的一个简单实现Demo，来进入RMI框架源码的神奇世界吧。

复制代码

1
2
3
4
5
6
7
8
/**
 * @author King Chen
 * @Date: 2019/3/20 20:30
 */
public interface IHelloWorldService extends Remote {

    String sayHello(String name) throws RemoteException;
}

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
/**
 * @author King Chen
 * @Date: 2019/3/20 20:31
 */
public class HelloWorldServiceImpl extends UnicastRemoteObject implements IHelloWorldService {
    protected HelloWorldServiceImpl() throws RemoteException {
        super();
    }

    @Override
    public String sayHello(String name) throws RemoteException {
        return "Hello " + name;
    }
}

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
/**
 * @author King Chen
 * @Date: 2019/3/20 20:34
 */
public class Server {
    public static void main(String[] args) {
        try {
            IHelloWorldService service = new HelloWorldServiceImpl();
            LocateRegistry.createRegistry(1099);
            Naming.rebind("helloWorld", service);
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }
}

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
/**
 * @author King Chen
 * @Date: 2019/3/20 20:39
 */
public class Client {
    public static void main(String[] args) {
        try {
            IHelloWorldService service = (IHelloWorldService) Naming.lookup("helloWorld");
            System.out.println(service.sayHello("King"));
        } catch (NotBoundException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

远程对象发布-类图

远程引用层-类图

源码解读

发布远程对象

发布远程对象，看到上面的类图可以知道，这个地方会发布两个远程对象，一个是RegistryImpl、另外一个是我们自己写的RMI实现类对象；

从HelloServiceImpl的构造函数看起。调用了父类UnicastRemoteObject的构造方法，追溯到UnicastRemoteObject的私有方法exportObject()。这里做了一个判断，判断服务的实现是不是UnicastRemoteObject的子类，如果是，则直接赋值其ref(RemoteRef)对象为传入的UnicastServerRef对象。反之则调用UnicastRef的exportObject()方法。

因为HelloServiceImpl继承了UnicastRemoteObject，所以在服务启动的时候，会通过UnicastRemoteObject的构造方法把该对象进行发布

复制代码

1
2
3
4
5
    protected UnicastRemoteObject(int port) throws RemoteException
    {
        this.port = port;
        exportObject((Remote) this, port);
    }

服务端启动Registry服务

复制代码

1
LocateRegistry.createRegistry(1099);

从上面这段代码入手，采用神奇的Debug大法，开始往下看。可以发现服务端创建了一个RegistryImpl对象，这里做了一个判断，如果服务端制定的端口是1099并且系统开启了安全管理器，那么就可以在限定的权限集内绕过系统的安全校验。这里纯粹是为了提高效率，真正的逻辑在setup方法中

复制代码

public RegistryImpl(final int var1) throws RemoteException {
        this.bindings = new Hashtable(101);
        if (var1 == 1099 && System.getSecurityManager() != null) {
            try {
                AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
                    public Void run() throws RemoteException {
                        LiveRef var1x = new LiveRef(RegistryImpl.id, var1);
                        RegistryImpl.this.setup(new UnicastServerRef(var1x, (var0) -> {
                            return RegistryImpl.registryFilter(var0);
                        }));
                        return null;
                    }
                }, (AccessControlContext)null, new SocketPermission("localhost:" + var1, "listen,accept"));
            } catch (PrivilegedActionException var3) {
                throw (RemoteException)var3.getException();
            }
        } else {
            LiveRef var2 = new LiveRef(id, var1);
            this.setup(new UnicastServerRef(var2, RegistryImpl::registryFilter));
        }

}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
    public RegistryImpl(final int var1) throws RemoteException {
        this.bindings = new Hashtable(101);
        if (var1 == 1099 && System.getSecurityManager() != null) {
            try {
                AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
                    public Void run() throws RemoteException {
                        LiveRef var1x = new LiveRef(RegistryImpl.id, var1);
                        RegistryImpl.this.setup(new UnicastServerRef(var1x, (var0) -> {
                            return RegistryImpl.registryFilter(var0);
                        }));
                        return null;
                    }
                }, (AccessControlContext)null, new SocketPermission("localhost:" + var1, "listen,accept"));
            } catch (PrivilegedActionException var3) {
                throw (RemoteException)var3.getException();
            }
        } else {
            LiveRef var2 = new LiveRef(id, var1);
            this.setup(new UnicastServerRef(var2, RegistryImpl::registryFilter));
        }

    }

setup方法将指向正在初始化的RegistryImpl对象的远程引用ref(RemoteRef)赋值为传入的UnicastServerRef对象，这里涉及到向上转型，然后继续执行UnicastServerRef的exportObject方法

复制代码

1
2
3
4
    private void setup(UnicastServerRef var1) throws RemoteException {
        this.ref = var1;
        var1.exportObject(this, (Object)null, true);
    }

进入UnicastServerRef的exportObject()方法。可以看到，这里首先为传入的RegistryImpl创建一个代理，这个代理我们可以推断出就是后面服务于客户端的RegistryImpl的Stub(RegistryImpl_Stub)对象。然后将UnicastServerRef的skel(skeleton)对象设置为当前RegistryImpl对象。最后用skeleton、stub、UnicastServerRef对象、id和一个boolean值构造了一个Target对象，也就是这个Target对象基本上包含了全部的信息，等待TCP调用。调用UnicastServerRef的ref(LiveRef)变量的exportObject()方法。

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
    public Remote exportObject(Remote var1, Object var2, boolean var3) throws RemoteException {
        Class var4 = var1.getClass();

        Remote var5;
        try {
            var5 = Util.createProxy(var4, this.getClientRef(), this.forceStubUse);
        } catch (IllegalArgumentException var7) {
            throw new ExportException("remote object implements illegal remote interface", var7);
        }

        if (var5 instanceof RemoteStub) {
            this.setSkeleton(var1);
        }

        Target var6 = new Target(var1, this, var5, this.ref.getObjID(), var3);
        this.ref.exportObject(var6);
        this.hashToMethod_Map = (Map)hashToMethod_Maps.get(var4);
        return var5;
    }

注：上述参数类型说明【var1=RegistryImpl ; var2=null ; var3=true】，LiveRef与TCP通信的类

到上面为止，我们看到的都是一些变量的赋值和创建工作，还没有到连接层，这些引用对象将会被Stub和Skeleton对象使用。接下来就是连接层上的了。追溯LiveRef的exportObject()方法，很容易找到了TCPTransport的exportObject()方法。这个方法做的事情就是将上面构造的Target对象暴露出去。调用TCPTransport的listen()方法，listen()方法创建了一个ServerSocket，并且启动了一条线程等待客户端的请求。接着调用父类Transport的exportObject()将Target对象存放进ObjectTable中。

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
    public void exportObject(Target var1) throws RemoteException {
        synchronized(this) {
            this.listen();
            ++this.exportCount;
        }

        boolean var2 = false;
        boolean var12 = false;

        try {
            var12 = true;
            super.exportObject(var1);
            var2 = true;
            var12 = false;
        } finally {
            if (var12) {
                if (!var2) {
                    synchronized(this) {
                        this.decrementExportCount();
                    }
                }

            }
        }

        if (!var2) {
            synchronized(this) {
                this.decrementExportCount();
            }
        }

    }

到此，我们已经将RegistryImpl对象创建并起了服务等待客户端的请求。

客户端获取服务端Registry代理

复制代码

1
IHelloWorldService service = (IHelloWorldService) Naming.lookup("helloWorld");

从上面代码看起，容易追溯到LocateRegistry的getRegistry()方法。这个方法做的事情是通过传入的host和port构造RemoteRef对象，并创建一个本地代理。这个代理对象其实是RegistryImpl_Stub对象。这样客户端便有了服务端的RegistryImpl的代理(取决于ignoreStubClasses变量)。但注意此时这个代理其实还没有和服务端的RegistryImpl对象关联，毕竟是两个VM上面的对象，这里我们也可以猜测，代理和远程的Registry对象之间是通过sokcet消息来完成的。

复制代码

public static Registry getRegistry(String host, int port,
                                       RMIClientSocketFactory csf)
        throws RemoteException
    {
        Registry registry = null;

//下面两个if代码块，目的是获取仓库地址
        if (port <= 0)
            port = Registry.REGISTRY_PORT;

if (host == null || host.length() == 0) {
            // If host is blank (as returned by "file:" URL in 1.0.2 used in
            // java.rmi.Naming), try to convert to real local host name so
            // that the RegistryImpl's checkAccess will not fail.
            try {
                host = java.net.InetAddress.getLocalHost().getHostAddress();
            } catch (Exception e) {
                // If that failed, at least try "" (localhost) anyway...
                host = "";
            }
        }
        //与TCP通信的类
        LiveRef liveRef =
            new LiveRef(new ObjID(ObjID.REGISTRY_ID),
                        new TCPEndpoint(host, port, csf, null),
                        false);
        RemoteRef ref =
            (csf == null) ? new UnicastRef(liveRef) : new UnicastRef2(liveRef);
        //创建远程代理类，并引用LiveRef，好让动态代理时，能进行TCP通信
        return (Registry) Util.createProxy(RegistryImpl.class, ref, false);
    }

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
    public static Registry getRegistry(String host, int port,
                                       RMIClientSocketFactory csf)
        throws RemoteException
    {
        Registry registry = null;

        //下面两个if代码块，目的是获取仓库地址
        if (port <= 0)
            port = Registry.REGISTRY_PORT;

        if (host == null || host.length() == 0) {
            // If host is blank (as returned by "file:" URL in 1.0.2 used in
            // java.rmi.Naming), try to convert to real local host name so
            // that the RegistryImpl's checkAccess will not fail.
            try {
                host = java.net.InetAddress.getLocalHost().getHostAddress();
            } catch (Exception e) {
                // If that failed, at least try "" (localhost) anyway...
                host = "";
            }
        }
        //与TCP通信的类
        LiveRef liveRef =
            new LiveRef(new ObjID(ObjID.REGISTRY_ID),
                        new TCPEndpoint(host, port, csf, null),
                        false);
        RemoteRef ref =
            (csf == null) ? new UnicastRef(liveRef) : new UnicastRef2(liveRef);
        //创建远程代理类，并引用LiveRef，好让动态代理时，能进行TCP通信
        return (Registry) Util.createProxy(RegistryImpl.class, ref, false);
    }

调用RegistryImpl_Stub的ref(RemoteRef)对象的newCall()方法，将RegistryImpl_Stub对象传了进行，不要忘了构造它的时候，我们将服务器的主机端口等信息传了进去，也就是我们把服务器相关的信息也传进了newCall()方法。newCall()方法做的事情简单来看就是建立了跟远程RegistryImpl的Skeleton对象的连接。

复制代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
    public RemoteCall newCall(RemoteObject var1, Operation[] var2, int var3, long var4) throws RemoteException {
        clientRefLog.log(Log.BRIEF, "get connection");
        Connection var6 = this.ref.getChannel().newConnection();

        try {
            clientRefLog.log(Log.VERBOSE, "create call context");
            if (clientCallLog.isLoggable(Log.VERBOSE)) {
                this.logClientCall(var1, var2[var3]);
            }

            StreamRemoteCall var7 = new StreamRemoteCall(var6, this.ref.getObjID(), var3, var4);

            try {
                this.marshalCustomCallData(var7.getOutputStream());
            } catch (IOException var9) {
                throw new MarshalException("error marshaling custom call data");
            }

            return var7;
        } catch (RemoteException var10) {
            this.ref.getChannel().free(var6, false);
            throw var10;
        }
    }

连接建立之后自然就是发送请求了。我们知道客户端终究只是拥有Registry对象的代理，而不是真正的位于服务端的Registry对象本身，他们位于不同的虚拟机实例中，无法直接调用。必然时通过消息进行交互的。看看this.ref.invoke(var2);这里做了什么吧。容易追溯到StreamRemoteCall的executeCall()方法。看似本地调用，但其实很容易从代码中看出是通过tcp连接发送消息到服务端的。由服务端解析并处理调用。

复制代码

public void executeCall() throws Exception {
        DGCAckHandler var2 = null;

byte var1;
        try {
            if (this.out != null) {
                var2 = this.out.getDGCAckHandler();
            }

this.releaseOutputStream();
            DataInputStream var3 = new DataInputStream(this.conn.getInputStream());
            byte var4 = var3.readByte();
            if (var4 != 81) {
                if (Transport.transportLog.isLoggable(Log.BRIEF)) {
                    Transport.transportLog.log(Log.BRIEF, "transport return code invalid: " + var4);
                }

throw new UnmarshalException("Transport return code invalid");
            }

this.getInputStream();
            var1 = this.in.readByte();
            this.in.readID();
        } catch (UnmarshalException var11) {
            throw var11;
        } catch (IOException var12) {
            throw new UnmarshalException("Error unmarshaling return header", var12);
        } finally {
            if (var2 != null) {
                var2.release();
            }

}

switch(var1) {
        case 1:
            return;
        case 2:
            Object var14;
            try {
                var14 = this.in.readObject();
            } catch (Exception var10) {
                throw new UnmarshalException("Error unmarshaling return", var10);
            }

if (!(var14 instanceof Exception)) {
                throw new UnmarshalException("Return type not Exception");
            } else {
                this.exceptionReceivedFromServer((Exception)var14);
            }
        default:
            if (Transport.transportLog.isLoggable(Log.BRIEF)) {
                Transport.transportLog.log(Log.BRIEF, "return code invalid: " + var1);
            }

throw new UnmarshalException("Return code invalid");
        }
    }

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
    public void executeCall() throws Exception {
        DGCAckHandler var2 = null;

        byte var1;
        try {
            if (this.out != null) {
                var2 = this.out.getDGCAckHandler();
            }

            this.releaseOutputStream();
            DataInputStream var3 = new DataInputStream(this.conn.getInputStream());
            byte var4 = var3.readByte();
            if (var4 != 81) {
                if (Transport.transportLog.isLoggable(Log.BRIEF)) {
                    Transport.transportLog.log(Log.BRIEF, "transport return code invalid: " + var4);
                }

                throw new UnmarshalException("Transport return code invalid");
            }

            this.getInputStream();
            var1 = this.in.readByte();
            this.in.readID();
        } catch (UnmarshalException var11) {
            throw var11;
        } catch (IOException var12) {
            throw new UnmarshalException("Error unmarshaling return header", var12);
        } finally {
            if (var2 != null) {
                var2.release();
            }

        }

        switch(var1) {
        case 1:
            return;
        case 2:
            Object var14;
            try {
                var14 = this.in.readObject();
            } catch (Exception var10) {
                throw new UnmarshalException("Error unmarshaling return", var10);
            }

            if (!(var14 instanceof Exception)) {
                throw new UnmarshalException("Return type not Exception");
            } else {
                this.exceptionReceivedFromServer((Exception)var14);
            }
        default:
            if (Transport.transportLog.isLoggable(Log.BRIEF)) {
                Transport.transportLog.log(Log.BRIEF, "return code invalid: " + var1);
            }

            throw new UnmarshalException("Return code invalid");
        }
    }

至此，我们已经将客户端的服务查询请求发出了。服务端接收客户端的服务查询请求并返回给客户端结果。

这里我们继续跟踪server端代码的服务发布代码，一步步往上翻。

复制代码

private void listen() throws RemoteException {
        assert Thread.holdsLock(this);

TCPEndpoint var1 = this.getEndpoint();
        int var2 = var1.getPort();
        if (this.server == null) {
            if (tcpLog.isLoggable(Log.BRIEF)) {
                tcpLog.log(Log.BRIEF, "(port " + var2 + ") create server socket");
            }

try {
                this.server = var1.newServerSocket();
                Thread var3 = (Thread)AccessController.doPrivileged(new NewThreadAction(new TCPTransport.AcceptLoop(this.server), "TCP Accept-" + var2, true));
                var3.start();
            } catch (BindException var4) {
                throw new ExportException("Port already in use: " + var2, var4);
            } catch (IOException var5) {
                throw new ExportException("Listen failed on port: " + var2, var5);
            }
        } else {
            SecurityManager var6 = System.getSecurityManager();
            if (var6 != null) {
                var6.checkListen(var2);
            }
        }

}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
    private void listen() throws RemoteException {
        assert Thread.holdsLock(this);

        TCPEndpoint var1 = this.getEndpoint();
        int var2 = var1.getPort();
        if (this.server == null) {
            if (tcpLog.isLoggable(Log.BRIEF)) {
                tcpLog.log(Log.BRIEF, "(port " + var2 + ") create server socket");
            }

            try {
                this.server = var1.newServerSocket();
                Thread var3 = (Thread)AccessController.doPrivileged(new NewThreadAction(new TCPTransport.AcceptLoop(this.server), "TCP Accept-" + var2, true));
                var3.start();
            } catch (BindException var4) {
                throw new ExportException("Port already in use: " + var2, var4);
            } catch (IOException var5) {
                throw new ExportException("Listen failed on port: " + var2, var5);
            }
        } else {
            SecurityManager var6 = System.getSecurityManager();
            if (var6 != null) {
                var6.checkListen(var2);
            }
        }

    }

在TCP协议层发起socket监听，并采用多线程循环接收请求：TCPTransport.AcceptLoop(this.server);

再往下走，一堆判断。。。。。。然后我们直接跳过了，不知道怎么跳可以根据我上面的demo用debug大法走一下。下面直接贴核心代码serviceCall()方法

复制代码

public boolean serviceCall(final RemoteCall var1) {
        try {
            ObjID var39;
            try {
                var39 = ObjID.read(var1.getInputStream());
            } catch (IOException var33) {
                throw new MarshalException("unable to read objID", var33);
            }

Transport var40 = var39.equals(dgcID) ? null : this;
            Target var5 = ObjectTable.getTarget(new ObjectEndpoint(var39, var40));
            final Remote var37;
            if (var5 != null && (var37 = var5.getImpl()) != null) {
                final Dispatcher var6 = var5.getDispatcher();
                var5.incrementCallCount();

boolean var8;
                try {
                    transportLog.log(Log.VERBOSE, "call dispatcher");
                    final AccessControlContext var7 = var5.getAccessControlContext();
                    ClassLoader var41 = var5.getContextClassLoader();
                    ClassLoader var9 = Thread.currentThread().getContextClassLoader();

try {
                        setContextClassLoader(var41);
                        currentTransport.set(this);

try {
                            AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
                                public Void run() throws IOException {
                                    Transport.this.checkAcceptPermission(var7);
                                    var6.dispatch(var37, var1);
                                    return null;
                                }
                            }, var7);
                            return true;
                        } catch (PrivilegedActionException var31) {
                            throw (IOException)var31.getException();
                        }
                    } finally {
                        setContextClassLoader(var9);
                        currentTransport.set((Object)null);
                    }
                } catch (IOException var34) {
                    transportLog.log(Log.BRIEF, "exception thrown by dispatcher: ", var34);
                    var8 = false;
                } finally {
                    var5.decrementCallCount();
                }

return var8;
            }

throw new NoSuchObjectException("no such object in table");
        } catch (RemoteException var36) {
            RemoteException var2 = var36;
            if (UnicastServerRef.callLog.isLoggable(Log.BRIEF)) {
                String var3 = "";

try {
                    var3 = "[" + RemoteServer.getClientHost() + "] ";
                } catch (ServerNotActiveException var30) {
                }

String var4 = var3 + "exception: ";
                UnicastServerRef.callLog.log(Log.BRIEF, var4, var36);
            }

try {
                ObjectOutput var38 = var1.getResultStream(false);
                UnicastServerRef.clearStackTraces(var2);
                var38.writeObject(var2);
                var1.releaseOutputStream();
            } catch (IOException var29) {
                transportLog.log(Log.BRIEF, "exception thrown marshalling exception: ", var29);
                return false;
            }
        }

return true;
    }

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
    public boolean serviceCall(final RemoteCall var1) {
        try {
            ObjID var39;
            try {
                var39 = ObjID.read(var1.getInputStream());
            } catch (IOException var33) {
                throw new MarshalException("unable to read objID", var33);
            }

            Transport var40 = var39.equals(dgcID) ? null : this;
            Target var5 = ObjectTable.getTarget(new ObjectEndpoint(var39, var40));
            final Remote var37;
            if (var5 != null && (var37 = var5.getImpl()) != null) {
                final Dispatcher var6 = var5.getDispatcher();
                var5.incrementCallCount();

                boolean var8;
                try {
                    transportLog.log(Log.VERBOSE, "call dispatcher");
                    final AccessControlContext var7 = var5.getAccessControlContext();
                    ClassLoader var41 = var5.getContextClassLoader();
                    ClassLoader var9 = Thread.currentThread().getContextClassLoader();

                    try {
                        setContextClassLoader(var41);
                        currentTransport.set(this);

                        try {
                            AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
                                public Void run() throws IOException {
                                    Transport.this.checkAcceptPermission(var7);
                                    var6.dispatch(var37, var1);
                                    return null;
                                }
                            }, var7);
                            return true;
                        } catch (PrivilegedActionException var31) {
                            throw (IOException)var31.getException();
                        }
                    } finally {
                        setContextClassLoader(var9);
                        currentTransport.set((Object)null);
                    }
                } catch (IOException var34) {
                    transportLog.log(Log.BRIEF, "exception thrown by dispatcher: ", var34);
                    var8 = false;
                } finally {
                    var5.decrementCallCount();
                }

                return var8;
            }

            throw new NoSuchObjectException("no such object in table");
        } catch (RemoteException var36) {
            RemoteException var2 = var36;
            if (UnicastServerRef.callLog.isLoggable(Log.BRIEF)) {
                String var3 = "";

                try {
                    var3 = "[" + RemoteServer.getClientHost() + "] ";
                } catch (ServerNotActiveException var30) {
                }

                String var4 = var3 + "exception: ";
                UnicastServerRef.callLog.log(Log.BRIEF, var4, var36);
            }

            try {
                ObjectOutput var38 = var1.getResultStream(false);
                UnicastServerRef.clearStackTraces(var2);
                var38.writeObject(var2);
                var1.releaseOutputStream();
            } catch (IOException var29) {
                transportLog.log(Log.BRIEF, "exception thrown marshalling exception: ", var29);
                return false;
            }
        }

        return true;
    }