9.7 Binder系统_c++实现_编写程序
参考文件:
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:(参考:IMediaPlayerService.h)
ifndef ANDROID_IHELLOERVICE_H
#define ANDROID_IHELLOERVICE_H
................头文件..................
namespace android{
#define HELLO_SVR_CMD_SAYHELLO 1
#define HELLO_SVR_CMD_SAYHELLO_TO 2
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(参考:IMediaPlayerService.cpp)
#include LOG_TAG "HelloService"
#include "IHelloService.h"
namespace android{
status_t BnHelloService::onTransact(uint32_t code,const Parcel& data,Parcel* reply,uint32_t flags)
{
//解析数据,调用sayhello/sayhello_to
switch(code){
case HELLO_SVR_CMD_SAYHELLO:{
sayhello();
return NO_ERROR;
}
case HELLO_SVR_CMD_SAYHELLO_TO:{
//从data中取出参数
int32_t policy = data->readInt32();//把四字节的全零数据读出来
String16 name16 =data->readString16();
String8 name8(name16);
int cnt = sayhello_to(name8.string());
//把返回值写入reply传回去
reply->writeInt32(cnt);
return NO_ERROR;
}breakl
default:
return BBinder::onTransact(code,data,reply,flags);
}
}
void BnHelloService::sayhello(void);
{
static
int
cnt = 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(参考:IMediaPlayerService.cpp)
#include "IHelloService.h"
class BpHelloService:public BpInterface<IHelloService>
{
public:
BpHelloService(const sp<IBinder>& impl):BpInterface<IHelloService>(impl)
{
}
void sayhello(void)
{
//构造/发送数据
Parcel data,reply;
data.writeInt32(0);//data数据域可以自己定义,这里是为了统一
remote()->transact(HELLO_SVR_CMD_SAYHELLO,data,&reply);
}
void sayhello_to(const char *name)
{
//构造/发送数据
Parcel data,reply;
data.writeInt32(0);//data数据域可以自己定义,这里是为了统一
data.writeString16(String16(name));
remote()->transact(HELLO_SVR_CMD_SAYHELLO_TO,data,&reply);
return reply.readInt32(HelloService,"android.media.IMediaPlayerService");
}
}
IMPLEMENT_META_INTERFACE(HelloService,"android.meida.In");
}
test_server.cpp(参考:Main_mediaserver.cpp)
#define LOG_TAG “HelloService”
#include "IHelloService.h"
.................头文件.......................
using namespace android;
int main(void)
{
//add service //while(1){read data,解析数据,调用服务函数}
//打开驱动,mmap
sp<ProcessState> proc(ProcessState::self());
//获得BpServiceManager
sp<IServiceManager> sm = defaultServiceManager();
sm->addService(String16("hello"),new BnHelloService());
//循环体
ProcessState::self()->startThreadPool();
IPCThreadState::self()->joinThreadPool();
return 0;
}
test_client.cpp
#define LOG_TAG “HelloService”
#include "IHelloService.h"
.................头文件.......................
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;
}
//打开驱动,mmap
sp<ProcessState> proc(ProcessState::self());
//获得BpServiceManager
sp<IServiceManager> sm = defaultServiceManager();
sp<IBinder> binder = sm->getService(String16("hello"));
if(binder == 0)
{
ALOGI("can't get hello service\n");
return -1;
}
//service肯定是BpHelloService指针
sp<IHelloService> service = interface_cast<IHelloService>(binder);
//调用Service函数
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;
}
测试编译:
参考frameworks\av\media\mediaserver\Android.mk
编译:
a. 文件放入frameworks/testing/APP_0004_Binder_CPP_App
b. cd /work/android-5.0.2/
. setenv
lunch //选择23. full_tiny4412-eng
c. cd frameworks/testing/APP_0004_Binder_CPP_App
mmm .
测试:
a. 重新编译内核让它支持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, 并使用新的zImage启动单板
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. 执行 test_server, test_client
./test_server &
logcat HelloService:* *:S &
./test_client hello
./test_client hello weidongshan