9.7 Binder System _c++ Implementation _ programming

Reference files:
Frameworks\av\include\media\imediaplayerservice.h (Imediaplayerservice,bnmediaplayerservice)
Frameworks\av\media\libmedia\imediaplayerservice.cpp (Bpmediaplayerservice)
Frameworks\av\media\libmediaplayerservice\mediaplayerservice.h
Frameworks\av\media\libmediaplayerservice\mediaplayerservice.cpp
Frameworks\av\media\mediaserver\main_mediaserver.cpp (server, AddService)

IHelloService.h: (Reference: IMediaPlayerService.h)

Ifndef Android_ihelloervice_h

#define Android_ihelloervice_h

................ The header file ........ .....

Namespace android{

Class Ihelloservice:public IInterface

{

Public

Declare_meta_interface (HelloService);

virtual void SayHello (void) = 0;

virtual int sayhello_to (const char *name) = 0;

};

Class Bnhelloservice:public Bninterface<ihelloservice>

{

Public

Virtual status_t ontransact (uint32_t code,const parcel& data,parcel* reply,uint32_t flags = 0);

virtual void SayHello (void);

virtual int sayhello_to (const char *name);

}

}

#endfi

BnHelloService.cpp (reference: IMediaPlayerService.cpp)

#include Log_tag "HelloService"

#include "IHelloService.h"

#define HELLO_SVR_CMD_SAYHELLO     1 #define HELLO_SVR_CMD_SAYHELLO_TO  2

Namespace android{

status_t bnhelloservice::ontransact (uint32_t code,const parcel& data,parcel* reply,uint32_t flags)

{

Parse data, call sayhello/sayhello_to

Switch (code) {

Case hello_svr_cmd_sayhello:{

SayHello ();

return no_error;

}

Case hello_svr_cmd_sayhello_to:{

Extracting parameters from data

int32_t policy = Data->readint32 ();//read out four bytes of all 0 data

String16 Name16 =data->readstring16 ();

String8 Name8 (NAME16);

int cnt = sayhello_to (name8.string ());

Write the return value to reply and pass it back.

Reply->writeint32 (CNT);

return no_error;

}breakl

Default

Return Bbinder::ontransact (code,data,reply,flags);

}

}

void Bnhelloservice::sayhello (void);

{

    　　staticintcnt = 0;

    　　 ALOGI ( "say hello : %d\n" , ++cnt);

}

int bnhelloservice::sayhello_to (const char *name);

{

    　　 static int cnt = 0;     　　ALOGI ( "say hello to %s : %d\n" , name, ++cnt);     　　 return cnt;

}

　　

}

BpHelloService.cpp (reference: IMediaPlayerService.cpp)

#include "IHelloService.h"

#define HELLO_SVR_CMD_SAYHELLO     1 #define HELLO_SVR_CMD_SAYHELLO_TO  2

Class Bphelloservice:public Bpinterface<ihelloservice>

{

Public

Bphelloservice (const sp<ibinder>& impl):bpinterface<ihelloservice> (Impl)

{

}

void SayHello (void)

{

Structuring/Sending data

Parcel data,reply;

Data.writeint32 (0);//data data fields can be defined by themselves, and this is to unify

Remote ()->transact (hello_svr_cmd_sayhello,data,&reply);

}

void sayhello_to (const char *name)

{

Structuring/Sending data

Parcel data,reply;

Data.writeint32 (0);//data data fields can be defined by themselves, and this is to unify

Data.writestring16 (STRING16 (name));

Remote ()->transact (hello_svr_cmd_sayhello_to,data,&reply);

Return Reply.readint32 (HelloService, "Android.media.IMediaPlayerService");

}

}

Implement_meta_interface ();

Test_server.cpp (reference: Main_mediaserver.cpp)

#define LOG_TAG "HelloService"

#include "IHelloService.h"

................. The header file ......... .......

using namespace Android;

int main (void)

{

Add service//while (1) {read data, parsing data, invoking service function}

Open Drive, Mmap

sp<processstate> proc (processstate::self ());

Get Bpservicemanager

sp<iservicemanager> sm = Defaultservicemanager ();

Sm->addservice (String16 ("Hello"), new Bnhelloservice ());

Loop body

Processstate::self ()->startthreadpool ();

Ipcthreadstate::self ()->jointhreadpool ();

return 0;

}

Test_client.cpp

#define LOG_TAG "Helloclient"

#include "IHelloService.h"

................. The header file ......... .......

using namespace Android;

void Main (int argc,char **argv)

{

    int cnt; 　　if (argc < 2){          ALOGI (stderr,  "Usage:\n" );         ALOGI (stderr,  "%s hello\n" , argv[0]);         ALOGI (stderr,  "%s hello <name>\n" , argv[0]);          return -1;      }GetService

Open Drive, Mmap

sp<processstate> proc (processstate::self ());

Get Bpservicemanager

sp<iservicemanager> sm = Defaultservicemanager ();

sp<ibinder> Binder = Sm->getservice (String16 ("Hello"));

if (binder = = 0)

{

Alogi ("Can ' t get Hello service\n");

return-1;

}

sp<ihelloservice> service = interface_cast<ihelloservice> (binder);

Calling the service function

if (ARGC < 3) {

Service->sayhello ();

Alogi ("Client call SayHello");

}

else{

CNT = service->sayhello_to (argv[2]);

Alogi ("Client Call sayhello_to,cnt =%d", CNT);

}

return 0;

}

Test compilation:

Reference frameworks\av\media\mediaserver\android.mk

Compile:
A. File into Frameworks/testing/app_0004_binder_cpp_app
B. cd/work/android-5.0.2/
. Setenv
Lunch//Select 23. Full_tiny4412-eng
C. CD Frameworks/testing/app_0004_binder_cpp_app
Mmm.

Test:
A. Recompile the kernel and let IT support NFS
Make Menuconfig
<*> NFS Client Support | |
[*] NFS Client Support for NFS Version 3 | |
[*] NFS client Support for the NFSv3 ACL Protocol extension | |
[*] NFS Client Support for NFS version 4 | |
[*] NFS Client Support for NFSv4.1 (experimental)

Make zimage and use the new zimage to start the veneer

B. Mount NFS
Su
Ifconfig eth0 192.168.1.100
BusyBox mount-t nfs-o nolock,vers=2 192.168.1.123:/work/nfs_root/mnt

C. Implementation of Test_server, test_client

./test_server &
Logcat helloservice:* *:s &
./test_client Hello
./test_client Hello Weidongshan

9.7 Binder System _c++ Implementation _ programming