Android IPC 通讯机制源码分析

核心提示：android.app.testServer.ITestServer.Stub{int mClientCount = 0;testServerClient mClient[];@Overridepublic android.app.testServer.ITestClient.Stub connect(ITestCli

android.app.testServer.ITestServer.Stub

{

int mClientCount = 0;

testServerClient mClient[];

@Override

public android.app.testServer.ITestClient.Stub connect(ITestClient client) throws RemoteException

{

// TODO Auto-generated method stub

testServerClient tClient = new testServerClient(this, client); //为Client创建

mClient[mClientCount] = tClient; //不同的IClient

mClientCount ++;

System.out.printf("*** Server connect client is %d", client.asBinder());

return tClient;

}

@Override

public void receivedData(int count) throws RemoteException

{

// TODO Auto-generated method stub

}

Public static class testServerClient extends android.app.testServer.ITestClient.Stub

{

public android.app.testServer.ITestClient mClient;

public TestServerServer mServer;

public testServerClient(TestServerServer tServer, android.app.testServer.ITestClient tClient)

{

mServer = tServer;

mClient = tClient;

}

public IBinder asBinder()

{

// TODO Auto-generated method stub

return this;

}

}

}

这仅仅是个Service的demo而已，如果添加这个作为system Service还得改一下android代码avoid permission check!

总结：

假定一个Client A 进程与Service B 进程要建立IPC通信，通过前面的分析我们知道他的流程如下：

1：Service B 打开Binder driver， 将自己的进程信息注册到kernel并为Service创建一个binder_ref。

2：Service B 通过Add_Service 将Service信息添加到service_manager进程

3：Service B 的Thread pool 挂起 等待client 的请求

4：Client A 调用open_driver打开Binder driver 将自己的进程信息注册到kernel并为Service创建一个binder_ref

5: Client A 调用defaultManagerService.getService 得到Service