HIDL --HelloWorld

https://source.android.com/devices/architecture/hidl/interfaces

https://www.jianshu.com/p/fd73ab98e423

https://www.jianshu.com/p/ca6823b897b5

mkdir -p hardware/interfaces/naruto/1.0/default 

创建接口文件。

vim  hardware/interfaces/naruto/1.0/INaruto.hal

package android.hardware.naruto@1.0;

interface INaruto {
    helloWorld(string name) generates (string result);
};

项目目录下生成hidl-gen后

# PACKAGE=android.hardware.naruto@1.0
# LOC=hardware/interfaces/naruto/1.0/default/
# make hidl-gen -j64
# hidl-gen -o $LOC -Lc++-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE
# hidl-gen -o $LOC -Landroidbp-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE

自动生成  Android,mk, Android.bp

default 目录会生成.cpp和.h 文件

制作service

touch hardware/interfaces/naruto/1.0/default/service/android.hardware.naruto@1.0-service.rc
touch hardware/interfaces/naruto/1.0/default/service/service.cpp

./hardware/interfaces/update-makefiles.sh

mmm hardware/interfaces/naruto/1.0/default/

 会生成一个android.hardware.naruto@1.0-impl.so, 生成在/vendor/lib64/hw/

 会生成一个android.hardware.naruto@1.0.so, 生成在/system/lib64/

实现service

我们知道，HIDL的实现有两种方式，一种是Binderized模式，另一种是Passthrough模式，我们看到上面有两行注释掉的代码，看来这个代码是关键，来选择实现方式是Binderized还是Passthrough。

我们这里使用Passthrough模式来演示，其实大家后面尝试这两种方式后会发现其实这两种本质是一样的，目前大部分厂商使用的都是Passthrough来延续以前的很多代码，但是慢慢的都会被改掉的，所以我们来打开这个注释。

实现接口

Naruto.h

# ifndef ANDROID_HARDWARE_NARUTO_V1_0_NARUTO_H
# define ANDROID_HARDWARE_NARUTO_V1_0_NARUTO_H
# include <android/hardware/naruto/1.0/INaruto.h>
# include <hidl/MQDescriptor.h>
# include <hidl/Status.h>

namespace android {
namespace hardware {
namespace naruto {
namespace V1_0 {
namespace implementation {

using ::android::hardware::hidl_array;
using ::android::hardware::hidl_memory;
using ::android::hardware::hidl_string;
using ::android::hardware::hidl_vec;
using ::android::hardware::Return;
using ::android::hardware::Void;
using ::android::sp;

struct Naruto : public INaruto {
    // Methods from INaruto follow.
    Return<void> helloWorld(const hidl_string& name, helloWorld_cb _hidl_cb) override;
    // Methods from ::android::hidl::base::V1_0::IBase follow.
};

// FIXME: most likely delete, this is only for passthrough implementations
extern "C" INaruto* HIDL_FETCH_INaruto(const char* name);

}  // namespace implementation
}  // namespace V1_0
}  // namespace naruto
}  // namespace hardware
}  // namespace android

# endif  // ANDROID_HARDWARE_NARUTO_V1_0_NARUTO_H

Naruto.cpp

# include "Naruto.h"

namespace android {
namespace hardware {
namespace naruto {
namespace V1_0 {
namespace implementation {

// Methods from INaruto follow.
Return<void> Naruto::helloWorld(const hidl_string& name, helloWorld_cb _hidl_cb) {
    // TODO implement
    char buf[100];
    ::memset(buf, 0x00, 100);
    ::snprintf(buf, 100, "Hello World, %s", name.c_str());
    hidl_string result(buf);

    _hidl_cb(result);
    return Void();
}

// Methods from ::android::hidl::base::V1_0::IBase follow.

INaruto* HIDL_FETCH_INaruto(const char* /* name */) {
    return new Naruto();
}

}  // namespace implementation
}  // namespace V1_0
}  // namespace naruto
}  // namespace hardware
}  // namespace android

service.cpp 定义了hal服务启动时候进行的操作，两个文件具体内容如下。

rc文件

service naruto_hal_service /vendor/bin/hw/android.hardware.naruto@1.0-service
    class hal
    user system
    group system

service.cpp

# define LOG_TAG "android.hardware.naruto@1.0-service"

# include <android/hardware/naruto/1.0/INaruto.h>

# include <hidl/LegacySupport.h>

using android::hardware::naruto::V1_0::INaruto;
using android::hardware::defaultPassthroughServiceImplementation;

int main() {
    return defaultPassthroughServiceImplementation<INaruto>();
}

这个service是注册了INaruto接口文件里面的接口，作为binder server端，很简单就一句话，因为我们使用了passthrough的模式，Android帮我们封装了这个函数，不需要我们自己去addService啦。

创建test目录，添加client.cpp文件和bp文件。

Android.bp

cc_binary {
    name: "android.hardware.naruto.client",
    defaults: ["hidl_defaults"],
    proprietary: true,
    relative_install_path: "hw",
    srcs: ["client.cpp"],
    shared_libs: [
        "libhidlbase",
        "libhidltransport",
        "libutils",
        "liblog",
        "android.hardware.naruto@1.0",

    ],
}

client.cpp

# include <android/hardware/naruto/1.0/INaruto.h>

# include <hidl/Status.h>

# include <hidl/LegacySupport.h>

# include <utils/misc.h>

# include <hidl/HidlSupport.h>

# include <stdio.h>

using android::hardware::naruto::V1_0::INaruto;
using android::sp;
using android::hardware::hidl_string;

int main()
{

    android::sp<INaruto> service = INaruto::getService();
    if(service == nullptr) {
        printf("Failed to get service
");
        return -1;
    }

    service->helloWorld("JayZhang", [&](hidl_string result) {
                printf("%s
", result.c_str());
        });

    return 0;
}

 执行./hardware/interfaces/update-makefiles.sh  更新编译范围，把test 和service 加到编译中。

执行mmm hardware/interfaces/naruto/1.0  编译生成客户端服务端可执行程序。

在manifest文件里添加追加

vendor接口的定义，不然在client端是没法拿到service的，在相应的manifest.xml里面加入：

<hal format="hidl">
    <name>android.hardware.naruto</name>
    <transport>hwbinder</transport>
    <version>1.0</version>
    <interface>
        <name>INaruto</name>
        <instance>default</instance>
    </interface>
</hal>

一个终端启动service，一个终端执行client。

 

HIDL注册回调的实现。

在demo的基础上，增加一个Callback回调接口。client端 实现回调接口。

INaruto.hal

package android.hardware.naruto@1.0;

import INarutoCallback;
interface INaruto {
    helloWorld(string name) generates (string result);
    
    init() generates();
    release() generates();
    setCallback(INarutoCallback cb)generates();
    
};

INarutoCallback.hal

package android.hardware.naruto@1.0;

interface INarutoCallback {
    oneway onNotify(HalEvent event);
    
};

types.hal

package android.hardware.naruto@1.0;

struct HalEvent{
    int32_t value;
};

client.cpp

# include <android/hardware/naruto/1.0/INaruto.h>
# include <android/hardware/naruto/1.0/types.h>
# include <android/hardware/naruto/1.0/INarutoCallback.h>

# include <hidl/Status.h>

# include <hidl/LegacySupport.h>

# include <utils/misc.h>

# include <hidl/HidlSupport.h>

# include <stdio.h>

using android::hardware::naruto::V1_0::INaruto;
using android::sp;
using android::hardware::hidl_string;
using android::hardware::naruto::V1_0::INarutoCallback;

using android::hardware::naruto::V1_0::HalEvent;
using android::hardware::Void;
using android::hardware::Return;

class myNarutoCallback:public INarutoCallback{
    
        public:
            myNarutoCallback(){}
            ~myNarutoCallback(){}
            Return<void>onNotify(const HalEvent &event){
                
                    printf("onNotify,value = %d
",event.value);
                    return Void();
                
            }
    
    
};


int main()
{

    android::sp<INaruto> service = INaruto::getService();
    if(service == nullptr) {
        printf("Failed to get service
");
        return -1;
    }

    service->helloWorld("JayZhang", [&](hidl_string result) {
                printf("%s
", result.c_str());
        });
        
       
    sp<myNarutoCallback>callback = new myNarutoCallback();
    printf("Failed to callback
");
    service->setCallback(callback);
    printf(" to callback
");
    ::sleep(10);
        
        
        

    return 0;
}

Naruto.cpp

#include "Naruto.h"

namespace android {
namespace hardware {
namespace naruto {
namespace V1_0 {
namespace implementation {


static sp<INarutoCallback> mCallback = nullptr;
static bool mExit = false;
static void threadLoop(){
    
    static int32_t count =0;
    HalEvent event;
    while(!mExit){
            ::sleep(1);
            event.value = count++;
            if(mCallback != nullptr){
                    mCallback->onNotify(event);
            }
        
    }
    printf("threadloop exit");
}


// Methods from INaruto follow.
Return<void> Naruto::helloWorld(const hidl_string& name, helloWorld_cb _hidl_cb) {
    // TODO implement
    char buf[100];
    ::memset(buf, 0x00, 100);
    ::snprintf(buf, 100, "Hello World, %s", name.c_str());
    hidl_string result(buf);

    _hidl_cb(result);
    return Void();
}

Return<void> Naruto::init() {
    // TODO implement
    return Void();
}

Return<void> Naruto::release() {
    // TODO implement
    return Void();
}

Return<void> Naruto::setCallback(const sp<INarutoCallback>& cb) {
    // TODO implement
    printf("Naruto11111111111:: setCallback:done");
    mCallback = cb;
    if(mCallback != nullptr)
    {
        printf("setCallback:done");
        threadLoop();    
    }
    printf("Naruto222222222222:: setCallback:done");
    return Void();
}


// Methods from ::android::hidl::base::V1_0::IBase follow.

INaruto* HIDL_FETCH_INaruto(const char* /* name */) {
    return new Naruto();
}

}  // namespace implementation
}  // namespace V1_0
}  // namespace naruto
}  // namespace hardware
}  // namespace android