Android9.0 HAL 层开发

一、生成 HAL 代码

1. 生成 hidl-gen 工具

1.  
   source source ./build/envsetup.sh
2.  
   lunch your_project
3.  
   make hidl-gen -j4

2. 编写接口文件

编写 types.hal, IHello.hal, IHelloCallback.hal，Android.bp

1.  
   1. IHello.hal 代码
2.  
   package vendor.tests.hardware.hello@1.0;
3.  
    
4.  
   import types;
5.  
   import IHelloCallback;
6.  
    
7.  
   interface IHello {
8.  
   get_data_char() generates(Status st, vec<int8_t> version);
9.  
    
10.  
    write_data_char(vec<int8_t>data, uint32_t size) generates(int32_t result);
11.  
     
12.  
    write_data_string(string data) generates(int32_t result);
13.  
    };

1.  
   2. types.hal 代码
2.  
   package vendor.tests.hardware.hello@1.0;
3.  
    
4.  
   enum Status : int32_t{
5.  
   SUCCESS,
6.  
   FAILURE
7.  
   };

1.  
   3. IHelloCallback.hal 代码
2.  
   package vendor.tests.hardware.hello@1.0;
3.  
    
4.  
   interface IHelloCallback {
5.  
   oneway onNotifyHelloEvent(string event);
6.  
   };

1.  
   4. Android.bp 代码
2.  
   如果 HAL 代码是在hardware/interfaces 目录下面，则可以在 hardware/interfaces/ 目录执行下面自动生成下面的 Android.bp
3.  
    
4.  
   ./update-makefiles.sh

1.  
   hidl_interface {
2.  
   name: "vendor.tests.hardware.hello@1.0",
3.  
   root: "vendor.tests.hardware",
4.  
   srcs: [
5.  
   "types.hal",
6.  
   "IHello.hal",
7.  
   "IHelloCallback.hal",
8.  
   ],
9.  
   interfaces: [
10.  
    "android.hidl.base@1.0",
11.  
    ],
12.  
    types: [
13.  
    "Status",
14.  
    ],
15.  
    gen_java: true,
16.  
    }

注意，由于 "vendor.test.hardware.hello@1.0" root 是 "vendor.test.hardware"
所以这个 root 一定是之前定义过的，如果自己新建的root，可以参考下面新建root，比如:

1.  
   root 包 bp参考写法:
2.  
   vendor/tests/hardware/Android.bp
3.  
   hidl_package_root {
4.  
       name: "vendor.tests.hardware", // root 包名
5.  
       path: "vendor/tests/interfaces" // root 路径
6.  
   }

那么所有依赖 "vendor.tests.hardware" 的都在 "vendor/tests/interfaces" 目录下面，比如 "vendor.tests.hardware.hello@1.0" 就在 "vendor/tests/interfaces" 下面新建 "hello/1.0" 目录，然后在该目录下面新建 "Android.bp"、 "types.hal"、"IHello.hal"、"IHelloCallback.hal" 等。

在"vendor/tests/interfaces/" 目录下面新建具体实现的目录，比如 "impl"，在impl下面新建 ”hello“对应的目录，比如 "hello/1.0/default"目录

3. 配置临时变量，包名，生成代码路径

1.  
   // 包名
2.  
   PACKAGE=vendor.tests.hardware.hello@1.0
3.  
    
4.  
   // 生成代码路径
5.  
   LOC=vendor/tests/interfaces/impl/hello/1.0/default/

4. 生成代码

1.  
   生成 c 代码：其中 LOC 指定生成代码的路径：
2.  
   hidl-gen -o $LOC -Lc -impl -rvendor.tests.hardware:vendor/tests/interfaces/ -randroid.hidl:system/libhidl/transport $PACKAGE
3.  
    
4.  
   其中 "-r" 参数作用 "-r <package:path root>: E.g., android.hardware:hardware/interfaces." 生成的 c 代码路径由 "-o" 参数指定，即上面的 LOC 变量定义的路径
5.  
    
6.  
   生成 c 代码的 Android.bp:
7.  
   hidl-gen -o $LOC -Landroidbp-impl -rvendor.tests.hardware:vendor/tests/interfaces/ -randroid.hidl:system/libhidl/transport $PACKAGE
8.  
    
9.  
   更新代码 bp 文件
10.  
    vendor/tests/interfaces/update-makefiles.sh
11.  
    // 该文件一般的 interfaces 的root 目录都会有，参考 hardware/interfaces/update-makefiles.sh

二、修改 c 实现代码

1. 通过类方式实现功能

修改 Helllo.cpp HelloCallback.cpp "struct" 为 "class"，并实现对应构造方法，析构方法。

1.  
   // Hello.h 代码
2.  
   #ifndef VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_H
3.  
   #define VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_H
4.  
    
5.  
   #include <vendor/tests/hardware/hello/1.0/IHello.h>
6.  
   #include <hidl/MQDescriptor.h>
7.  
   #include <hidl/Status.h>
8.  
    
9.  
   namespace vendor {
10.  
    namespace tests {
11.  
    namespace hardware {
12.  
    namespace hello {
13.  
    namespace V1_0 {
14.  
    namespace implementation {
15.  
     
16.  
    using ::android::hardware::hidl_array;
17.  
    using ::android::hardware::hidl_memory;
18.  
    using ::android::hardware::hidl_string;
19.  
    using ::android::hardware::hidl_vec;
20.  
    using ::android::hardware::Return;
21.  
    using ::android::hardware::Void;
22.  
    using ::android::sp;
23.  
     
24.  
    class Hello : public IHello {
25.  
    public:
26.  
    // Methods from ::vendor::tests::hardware::hello::V1_0::IHello follow.
27.  
    Return<void> get_data_char(get_data_char_cb _hidl_cb) override;
28.  
    Return<int32_t> write_data_char(const hidl_vec<int8_t>& data, uint32_t size) override;
29.  
    Return<int32_t> write_data_string(const hidl_string& data) override;
30.  
     
31.  
    // Methods from ::android::hidl::base::V1_0::IBase follow.
32.  
    Hello();
33.  
    ~Hello();
34.  
    void onServiceDied();
35.  
    };
36.  
     
37.  
    // FIXME: most likely delete, this is only for passthrough implementations
38.  
    // extern "C" IHello* HIDL_FETCH_IHello(const char* name);
39.  
     
40.  
    } // namespace implementation
41.  
    } // namespace V1_0
42.  
    } // namespace hello
43.  
    } // namespace hardware
44.  
    } // namespace tests
45.  
    } // namespace vendor
46.  
     
47.  
    #endif // VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_H

1.  
   // HelloCallback.h 代码
2.  
   #ifndef VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLOCALLBACK_H
3.  
   #define VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLOCALLBACK_H
4.  
    
5.  
   #include <vendor/tests/hardware/hello/1.0/IHelloCallback.h>
6.  
   #include <hidl/MQDescriptor.h>
7.  
   #include <hidl/Status.h>
8.  
    
9.  
   namespace vendor {
10.  
    namespace tests {
11.  
    namespace hardware {
12.  
    namespace hello {
13.  
    namespace V1_0 {
14.  
    namespace implementation {
15.  
     
16.  
    using ::android::hardware::hidl_array;
17.  
    using ::android::hardware::hidl_memory;
18.  
    using ::android::hardware::hidl_string;
19.  
    using ::android::hardware::hidl_vec;
20.  
    using ::android::hardware::Return;
21.  
    using ::android::hardware::Void;
22.  
    using ::android::sp;
23.  
     
24.  
    class HelloCallback : public IHelloCallback {
25.  
    // Methods from ::vendor::tests::hardware::hello::V1_0::IHelloCallback follow.
26.  
    Return<void> onNotifyHelloEvent(const hidl_string& event) override;
27.  
     
28.  
    // Methods from ::android::hidl::base::V1_0::IBase follow.
29.  
     
30.  
    };
31.  
     
32.  
    // FIXME: most likely delete, this is only for passthrough implementations
33.  
    // extern "C" IHelloCallback* HIDL_FETCH_IHelloCallback(const char* name);
34.  
     
35.  
    } // namespace implementation
36.  
    } // namespace V1_0
37.  
    } // namespace hello
38.  
    } // namespace hardware
39.  
    } // namespace tests
40.  
    } // namespace vendor
41.  
     
42.  
    #endif // VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLOCALLBACK_H
43.  
     
44.  
     
45.  
    // HelloCallback.cpp 代码
46.  
    #include "HelloCallback.h"
47.  
     
48.  
    namespace vendor {
49.  
    namespace tests {
50.  
    namespace hardware {
51.  
    namespace hello {
52.  
    namespace V1_0 {
53.  
    namespace implementation {
54.  
     
55.  
    // Methods from ::vendor::tests::hardware::hello::V1_0::IHelloCallback follow.
56.  
    Return<void> HelloCallback::onNotifyHelloEvent(const hidl_string& event) {
57.  
    // TODO implement
58.  
    return Void();
59.  
    }
60.  
     
61.  
     
62.  
    // Methods from ::android::hidl::base::V1_0::IBase follow.
63.  
     
64.  
    //IHelloCallback* HIDL_FETCH_IHelloCallback(const char* /* name */) {
65.  
    //return new HelloCallback();
66.  
    //}
67.  
    //
68.  
    } // namespace implementation
69.  
    } // namespace V1_0
70.  
    } // namespace hello
71.  
    } // namespace hardware
72.  
    } // namespace tests
73.  
    } // namespace vendor

2. 实现 HelloDeathListener 类

该类继承于 "android::hardware::hidl_death_recipient"，并实现 “serviceDied” 方法，在该方法中调用 Helllo 类的 "onServiceDied"方法

1.  
   // HelloDeathListener.h 代码
2.  
   #ifndef VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_DEATH_LISTENE_H
3.  
   #define VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_DEATH_LISTENE_H
4.  
    
5.  
   #include <hidl/MQDescriptor.h>
6.  
   #include <hidl/Status.h>
7.  
   #include <android-base/file.h>
8.  
   #include <android-base/logging.h>
9.  
   #include <android-base/properties.h>
10.  
    #include <android-base/stringprintf.h>
11.  
    #include <android-base/strings.h>
12.  
    #include "Hello.h"
13.  
    #include "HelloCallback.h"
14.  
     
15.  
    namespace vendor {
16.  
    namespace tests {
17.  
    namespace hardware {
18.  
    namespace hello {
19.  
    namespace V1_0 {
20.  
    namespace implementation {
21.  
     
22.  
    using ::android::hardware::hidl_array;
23.  
    using ::android::hardware::hidl_memory;
24.  
    using ::android::hardware::hidl_string;
25.  
    using ::android::hardware::hidl_vec;
26.  
    using ::android::hardware::Return;
27.  
    using ::android::hardware::Void;
28.  
    using ::android::hidl::base::V1_0::IBase;
29.  
    using ::android::sp;
30.  
    using ::android::wp;
31.  
     
32.  
    class Hello;
33.  
     
34.  
    class HelloDeathListener : public android::hardware::hidl_death_recipient {
35.  
    public:
36.  
    HelloDeathListener(Hello *hello);
37.  
    virtual ~HelloDeathListener();
38.  
    virtual void serviceDied(uint64_t cookie, const wp<IBase>& who) override;
39.  
    private:
40.  
    Hello *mHello;
41.  
    };
42.  
     
43.  
    } // namespace implementation
44.  
    } // namespace V1_0
45.  
    } // namespace hello
46.  
    } // namespace hardware
47.  
    } // namespace tests
48.  
    } // namespace vendor
49.  
     
50.  
    #endif // VENDOR_TESTS_HARDWARE_HELLO_V1_0_HELLO_DEATH_LISTENE_H
51.  
     
52.  
     
53.  
    // HelloDeathListener.cpp 代码
54.  
    #include "HelloDeathListener.h"
55.  
    #include <log/log.h>
56.  
     
57.  
    #undef LOG_TAG
58.  
    #define LOG_TAG "Hello@DeathListener"
59.  
     
60.  
    namespace vendor {
61.  
    namespace tests {
62.  
    namespace hardware {
63.  
    namespace hello {
64.  
    namespace V1_0 {
65.  
    namespace implementation {
66.  
     
67.  
    using namespace android::base;
68.  
    using namespace std;
69.  
     
70.  
    HelloDeathListener::HelloDeathListener(Hello *hello) {
71.  
    ALOGE("%s", __FUNCTION__);
72.  
    if (hello != nullptr) {
73.  
    mHello = hello;
74.  
    }
75.  
    }
76.  
     
77.  
    HelloDeathListener:: ~HelloDeathListener() {}
78.  
     
79.  
    void HelloDeathListener::serviceDied(uint64_t cookie, const wp<IBase>& who) {
80.  
    ALOGE("%s", __FUNCTION__);
81.  
    if (mHello != nullptr) {
82.  
    mHello->onServiceDied();
83.  
    }
84.  
    }
85.  
     
86.  
    } // namespace implementation
87.  
    } // namespace V1_0
88.  
    } // namespace hello
89.  
    } // namespace hardware
90.  
    } // namespace tests
91.  
    } // namespace vendor

3. 根据 IHello.hal 实现对应接口

1.  
   IHello.hal 中接口:
2.  
    
3.  
   // 该方法参数都为 输出参数，即返回值为 Status，返回数据为 vector<int8_t> 实际为 vector<char>，可进行数据转换。
4.  
   get_data_char() generates(Status st, vec<int8_t> version);
5.  
    
6.  
   // 该方法参数为 两个输入参赛，一个返回值。
7.  
   write_data_char(vec<int8_t>data, uint32_t size) generates(int32_t result);
8.  
    
9.  
   / 该方法参数为 一个输入参赛，一个返回值。
10.  
    write_data_string(string data) generates(int32_t result);
11.  
     
12.  
     
13.  
    // Hello.cpp 实现:
14.  
    #include "Hello.h"
15.  
    #include <string.h>
16.  
    #include <log/log.h>
17.  
    #include <android/log.h>
18.  
     
19.  
    namespace vendor {
20.  
    namespace tests {
21.  
    namespace hardware {
22.  
    namespace hello {
23.  
    namespace V1_0 {
24.  
    namespace implementation {
25.  
     
26.  
    Hello::Hello()
27.  
    {}
28.  
     
29.  
    Hello::~Hello()
30.  
    {
31.  
     
32.  
    }
33.  
     
34.  
    void Hello::onServiceDied()
35.  
    {
36.  
    ALOGE("invoked ");
37.  
    }
38.  
     
39.  
     
40.  
    // Methods from ::vendor::tests::hardware::hello::V1_0::IHello follow.
41.  
    Return<void> Hello::get_data_char(get_data_char_cb _hidl_cb) {
42.  
    static char buffer[] = "hello return data!";
43.  
    std::vector<int8_t> data(buffer, buffer strlen(buffer));
44.  
     
45.  
    _hidl_cb(Status::SUCCESS, (const hidl_vec<int8_t>)data);
46.  
    return Void();
47.  
    }
48.  
     
49.  
    Return<int32_t> Hello::write_data_char(const hidl_vec<int8_t>& data, uint32_t size) {
50.  
    ALOGE("data: %s, len: %d", data.data(), size);
51.  
     
52.  
    return int32_t {0};
53.  
    }
54.  
     
55.  
    Return<int32_t> Hello::write_data_string(const hidl_string& data) {
56.  
    ALOGE("data: %s", data.c_str());
57.  
    return int32_t {0};
58.  
    }
59.  
     
60.  
    // Methods from ::android::hidl::base::V1_0::IBase follow.
61.  
     
62.  
    //IHello* HIDL_FETCH_IHello(const char* /* name */) {
63.  
    //return new Hello();
64.  
    //}
65.  
    //
66.  
    } // namespace implementation
67.  
    } // namespace V1_0
68.  
    } // namespace hello
69.  
    } // namespace hardware
70.  
    } // namespace tests
71.  
    } // namespace vendor

4. 实现HelloService 

1.  
   // HelloService.cpp 代码
2.  
   #define LOG_TAG "vendor.tests.hardware.hello@1.0-service"
3.  
    
4.  
   #include <stdio.h>
5.  
   #include <android/log.h>
6.  
   #include <utils/SystemClock.h>
7.  
   #include <hidl/HidlTransportSupport.h>
8.  
   #include "Hello.h"
9.  
    
10.  
    using namespace android;
11.  
    using namespace android::hardware;
12.  
    using namespace vendor::tests::hardware::hello::V1_0::implementation;
13.  
    using namespace std::placeholders;
14.  
     
15.  
    int main(int /* argc */, char * /* argv */[])
16.  
    {
17.  
    auto service = std::make_unique<Hello>();
18.  
    configureRpcThreadpool(4, true /* callerWillJoin */);
19.  
    ALOGD("Hello HAL service starting");
20.  
    status_t status = service->registerAsService();
21.  
    if (status != OK)
22.  
    {
23.  
    ALOGE("Unable to register Hello HAL service (%d)", status);
24.  
    return 1;
25.  
    }
26.  
    ALOGI("Register Hello Service successfully");
27.  
    joinRpcThreadpool();
28.  
    return 1;
29.  
    }

5. 更新 Android.bp

1.  
   // Android.bp 代码
2.  
   // new add
3.  
   cc_defaults {
4.  
   name: "hello_defaults",
5.  
   shared_libs: [
6.  
   "liblog",
7.  
   "libutils",
8.  
   "libhidlbase",
9.  
   "libhardware",
10.  
    "libhidltransport",
11.  
    ],
12.  
    vendor: true,
13.  
    compile_multilib: "64",
14.  
    cflags: [
15.  
    "-Wall",
16.  
    "-Wextra",
17.  
    "-Werror",
18.  
    "-Wno-unused-parameter"
19.  
    ],
20.  
    }
21.  
     
22.  
    // modify
23.  
    cc_library_shared {
24.  
    name: "vendor.tests.hardware.hello@1.0-impl",
25.  
    relative_install_path: "hw",
26.  
    defaults: ["hello_defaults"],
27.  
    proprietary: true,
28.  
    srcs: [
29.  
    "Hello.cpp",
30.  
    "HelloCallback.cpp",
31.  
    "HelloDeathListener.cpp",
32.  
    ],
33.  
    shared_libs: [
34.  
    "libhidlbase",
35.  
    "libhidltransport",
36.  
    "libutils",
37.  
    "vendor.tests.hardware.hello@1.0",
38.  
    ],
39.  
    }
40.  
     
41.  
    // new add
42.  
    cc_binary {
43.  
    name: "vendor.tests.hardware.hello@1.0-service",
44.  
    relative_install_path: "hw",
45.  
    defaults: ["hello_defaults"],
46.  
    init_rc: ["vendor.tests.hardware.hello@1.0-service.rc"],
47.  
    rtti: false,
48.  
    srcs: [
49.  
    "HelloService.cpp"
50.  
    ],
51.  
    header_libs: [],
52.  
    shared_libs: [
53.  
    "libbase",
54.  
    "libprotobuf-cpp-lite",
55.  
    "libcommon-base",
56.  
    "vendor.tests.hardware.hello@1.0",
57.  
    "vendor.tests.hardware.hello@1.0-impl",
58.  
    ],
59.  
    cppflags: [
60.  
    "-fexceptions"
61.  
    ]
62.  
    }

6.  HAL service 启动 rc文件

1.  
   //vendor.tests.hardware.hello@1.0-service.rc
2.  
   service vendor.tests.hardware.hello-1.0 /vendor/bin/hw/vendor.tests.hardware.hello@1.0-service
3.  
   class hal
4.  
   user system
5.  
   group system inet

7. selinux 标签修改

1.  
   在 xxx.te 中对 service 标签进行修改
2.  
    
3.  
   // file_contexs
4.  
   /(vendor|system/vendor)/bin/hw/vendor.tests.hardware.hello@1.0-service u:object_r:hal_hello_default_exec:s0
5.  
    
6.  
   // hal_hello_default_exec.te
7.  
   # add for hello
8.  
   type hal_hello_default, domain, mlstrustedsubject;
9.  
   typeattribute hal_hello_default nobohaldomain, mlstrustedsubject;
10.  
    hal_server_domain(hal_hello_default, hal_hello)
11.  
    type hal_hello_default_exec, exec_type, vendor_file_type, file_type;
12.  
     
13.  
    init_daemon_domain(hal_hello_default)
14.  
     
15.  
    # Allow hwbinder call from hal client to server
16.  
    binder_call(hal_hello_client, hal_hello_server)
17.  
     
18.  
    # Add hwservice related rules
19.  
    add_hwservice(hal_hello_server, hal_hello_hwservice)
20.  
    allow hal_hello_client hal_hello_hwservice:hwservice_manager find;
21.  
     
22.  
    #hwbinder_use(hal_hello)
23.  
    get_prop(hal_hello, hwservicemanager_prop)
24.  
    allow hal_hello_default mnt_vendor_file:dir rw_dir_perms;
25.  
     
26.  
    allow hal_hello_default tee_device:chr_file { ioctl open read write };
27.  
    allow hal_hello_default ion_device:chr_file { ioctl open read write };
28.  
     
29.  
     
30.  
    typeattribute hal_hello_default system_writes_vendor_properties_violators;
31.  
     
32.  
    allow hal_hello_default mnt_vendor_crypto_file:dir create_dir_perms;
33.  
    allow hal_hello_default mnt_vendor_crypto_file:file create_file_perms;
34.  
    allow hal_hello_default mnt_vendor_crypto_file:filesystem getattr;
35.  
    allow hal_hello_default vendor_data_nfs_file:dir search;
36.  
     
37.  
    allow hal_hello_default pki_sdk_file:file { read open execute getattr map };
38.  
    allow hal_hello_default default_prop:file { read open execute getattr map };
39.  
    allow hal_hello_default vendor_bean_prop:file { read open execute getattr map };
40.  
    allow hal_hello_default property_socket:sock_file { write };
41.  
    allow hal_hello_default init:unix_stream_socket { connectto };
42.  
     
43.  
    allow hal_hello_default vfat:dir create_dir_perms;
44.  
    allow hal_hello_default vfat:file create_file_perms;
45.  
    allow hal_hello_default vfat:filesystem getattr;
46.  
    allow hal_hello_default mnt_user_log_file:lnk_file read;
47.  
    allow hal_hello_default mnt_user_file:dir search;
48.  
    allow hal_hello_default mnt_user_file:lnk_file read;
49.  
    allow hal_hello_default unlabeled:dir { search write read add_name open create };
50.  
    allow hal_hello_default unlabeled:file { read append write open create getattr };

1.  
   // 其中 hal_hello_default_exec 需要自己定义，具体参考系统中的其他修改
2.  
   // 同时 attributes、hwservice.te、hwservice_contexts 需要对应修改
3.  
    
4.  
   // attributes 修改
5.  
   attribute hal_hello;
6.  
   expandattribute hal_hello true;
7.  
   attribute hal_hello_client;
8.  
   expandattribute hal_hello_client true;
9.  
   attribute hal_hello_server;
10.  
    expandattribute hal_hello_server false;
11.  
     
12.  
    // hwservice.te
13.  
    type hal_hello_hwservice, hwservice_manager_type;
14.  
     
15.  
    // hwservice_contexts
16.  
    vendor.tests.hardware.hello::IHello u:object_r:hal_hello_hwservice:s0

8. 对应模块加入系统编译

1.  
   xxx.mk
2.  
    
3.  
   PRODUCT_PACKAGES = \
4.  
   vendor.tests.hardware.hello@1.0 \
5.  
   vendor.tests.hardware.hello@1.0-impl \
6.  
   vendor.tests.hardware.hello@1.0-service \

三、client 实现

1.  
   #define LOG_TAG "HelloClient"
2.  
    
3.  
   #include <log/log.h>
4.  
   #include <android/log.h>
5.  
    
6.  
   #include <hidl/HidlSupport.h>
7.  
   #include <hidl/Status.h>
8.  
   #include <vendor/tests/hardware/hello/1.0/IHello.h>
9.  
    
10.  
    using namespace vendor::tests::hardware::hello::V1_0;
11.  
     
12.  
    using ::android::hardware::hidl_array;
13.  
    using ::android::hardware::hidl_memory;
14.  
    using ::android::hardware::hidl_string;
15.  
    using ::android::hardware::hidl_vec;
16.  
    using ::android::hardware::Return;
17.  
    using ::android::hardware::Void;
18.  
    using vendor::tests::hardware::hello::V1_0::IHello;
19.  
    using vendor::tests::hardware::hello::V1_0::Status;
20.  
    using android::sp;
21.  
    using android::status_t;
22.  
     
23.  
    int main(){
24.  
    sp<IHello> helloService = IHello::getService();
25.  
    if (helloService == nullptr) {
26.  
    LOGE("can't not get IHello service!");
27.  
    return -1;
28.  
    }
29.  
     
30.  
    Status status = FAILURE;
31.  
    std::vector<int8_t> readBuffer;
32.  
    helloService->get_data_char([&](Status st, std::vector<int8_t> data){
33.  
    status = st; readBuffer = data;
34.  
    });
35.  
     
36.  
     
37.  
    char str[] = "write data string .....";
38.  
    std::vector<int8_t> writeBuffer(str, str strlen(str));
39.  
    int len = helloService->write_data_char(writeBuffer, strlen(str));
40.  
     
41.  
    }

四. 完整测试代码

https://download.csdn.net/download/SHK242673/72544934

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