一般创建自定义系统服务的代码目录为：
frameworks/native/services/
新增目录名：customize
在customize下新增目录include用于存放头文件。
在customize下目录结构如下：
CustomizeManagerService.cpp
ICustomizeManagerService.cpp
include/CustomizeManagerService.h
include/ICustomizeManagerService.h
Android.bp
在include/ICustomizeManagerService.h中新增如下内容：
#ifndef ICustomizeManagerService_H
#define ICustomizeManagerService_H
#include <binder/IInterface.h>
#include <binder/IPCThreadState.h>
#include <binder/IResultReceiver.h>
#include <binder/IServiceManager.h>
#include <binder/MemoryBase.h>
#include <binder/MemoryHeapBase.h>
#include <binder/Parcel.h>
#include <utils/String8.h>
namespace android
{
//IInterface：定义的接口，在bp以及bn都要按这个函数去实现，不允许出现多余的入参或者不同的返回值
class ICustomizeManagerService: public IInterface
{
public:
//关联server端的实现类
DECLARE_META_INTERFACE(CustomizeManagerService);
//纯虚函数
virtual int customeize() = 0;
};
//BnInterface: Server 端类
class BnCustomizeManagerService : public BnInterface<ICustomizeManagerService>
{
public:
virtual status_t onTransact(uint32_t code, const Parcel &data, Parcel *reply, uint32_t flags = 0);
};
}; //namespace android
#endif
在ICustomizeManagerService.cpp中新增如下内容：
#undef LOG_TAG
#define LOG_TAG "ICustomizeManagerService"
#include <binder/Parcel.h>
#include <fcntl.h>
#include "ICustomizeManagerService.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <stdint.h>
#include <utils/Log.h>
#include <utils/String8.h>
namespace android {
enum{
CREATE = IBinder::FIRST_CALL_TRANSACTION,
CUSTOMIZE,
};
#define NATIVESERVICE_NAME "customizemanagerservice"
//Client 端
class BpCustomizeManagerService : public BpInterface<ICustomizeManagerService>
{
public:
explicit BpCustomizeManagerService(const sp<IBinder>& impl)
: BpInterface <ICustomizeManagerService>(impl)
{
ALOGD("create Service \n");
}
int customeize(){
//client和server端的参数或者返回值传递通过Parcel
Parcel data, reply;
data.writeInterfaceToken(ICustomizeManagerService::getInterfaceDescriptor());
remote()->transact(CUSTOMIZE, data, &reply);
return reply.readInt32();
}
};
IMPLEMENT_META_INTERFACE(CustomizeManagerService, NATIVESERVICE_NAME);
//Server 端
status_t BnCustomizeManagerService ::onTransact(uint32_t code, const Parcel &data, Parcel *reply, uint32_t flags){
switch (code)
{
case CUSTOMIZE:
{
CHECK_INTERFACE(ICustomizeManagerService, data, reply);
//此处方法必须和Interface中保持一致，实现是在CustomizeManagerService.cpp中实现的
int ret = customeize();
reply->writeInt32(ret);
return NO_ERROR;
}
default:
return BBinder::onTransact(code, data, reply, flags);
};
}
}; //namespace android
include/CustomizeManagerService.h中新增如下内容
#ifndef CustomizeManagerService_H
#define CustomizeManagerService_H
#include <binder/IInterface.h>
#include <binder/Parcel.h>
#include "ICustomizeManagerService.h"
#include <utils/Mutex.h>
#include <utils/RefBase.h>
#include <utils/String8.h>
namespace android {
using namespace android;
class CustomizeManagerService : public BnCustomizeManagerService {
public:
CustomizeManagerService();
~CustomizeManagerService();
int customeize();
};
};
#endif
CustomizeManagerService.cpp中新增如下内容
#undef LOG_TAG
#define LOG_TAG "CustomizeManagerService"
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "CustomizeManagerService .h"
#include <utils/Log.h>
#include <utils/String8.h>
#include <android-base/properties.h>
#include <cutils/properties.h>
namespace android {
CustomizeManagerService ::CustomizeManagerService () {
bindHidlService();
}
CustomizeManagerService ::~CustomizeManagerService () {
}
int CustomizeManagerService ::customeize() {
int ret = 100;
return ret;
}
};
其中需注意的是IInterface中的纯虚方法，在Bn和Bp去实现的时候，要一模一样
需注意的是Android 12自定义native service时，需要在以下文件中添加自己的服务名字才可以，否则会报错：
error: static_assert failed due to requirement 'internal::allowedManualInterface("xxx")' : Manually written binder interfaces are considered error prone and frequently have bugs. The preferred way to add interfaces is to define an .aidl file to auto-generate the interface. If an interface must be manually written, add its name to the whitelist."
frameworks/native/libs/binder/include/binder/IInterface.h
在kManualInterfaces中增加自己的服务名即可:
namespace internal {
constexpr const char* const kManualInterfaces[] = {
"android.app.IActivityManager",
"android.app.IUidObserver",
"android.drm.IDrm",
......
+ "customizemanagerserver",
nullptr,
};
Android.bp
这个里面多了很多访问hal服务以及Ahandler相关的代码
cc_library_shared {
name: "libcustomizemanagerserver",
srcs: [
"CustomizeManagerService.cpp",
"ICustomizeManagerService.cpp",
],
shared_libs: [
"libcutils",
"libbinder",
"liblog",
"libutils",
"libhidltransport",
"libhidlbase",
"[email protected]",
"libstagefright_foundation",
"libstagefright",
"libmedia",
"libmedia_codeclist",
],
cflags: [
"-Werror",
"-Wno-error=deprecated-declarations",
"-Wno-unused-parameter",
"-Wall",
"-Wunused-variable",
"-Wswitch",
],
include_dirs:[
"frameworks/native/services/customizemanagerserver/include",
"frameworks/av/media/libstagefright/foundation/include",
"frameworks/av/media/libstagefright/foundation/include/media/stagefright/foundation",
],
header_libs: [
"libaudiohal_headers",
],
}
cc_binary {
name: "customizemanagerserver",
init_rc: ["customizemanagerserver.rc"],
srcs: [
"main_customizemanagerserver.cpp",
],
shared_libs: [
"libcutils",
"libutils",
"liblog",
"libbinder",
"libcustomizemanagerserver",
"libhidlbase",
"libbase",
"libhidltransport",
"[email protected]",
"libstagefright_foundation",
"libstagefright",
"libmedia",
"libmedia_codeclist",
],
include_dirs:[
"frameworks/native/services/customizemanagerserver/include",
"frameworks/av/media/libstagefright/foundation/include",
"frameworks/av/media/libstagefright/foundation/include/media/stagefright/foundation",
],
cflags: [
"-Werror",
"-Wno-error=deprecated-declarations",
"-Wno-unused-parameter",
"-Wall",
],
header_libs: [
"libaudiohal_headers",
],
}
customizemanagerserver.rc如下：
service customizemanagerserver /system/bin/customizemanagerserver
class main
user system
group system
oneshot
on property:sys.boot_completed=1
start customizemanagerserver