好用的h5网站,在线网站地图生成器,wordpress+手机端,怎么把做的网页放网站HwBinder与普通Binder是一样的,区别是前者是专门给硬件使用#xff0c;后者是给一般的应用程序使用#xff0c;为了不影响现有的binder#xff0c;单独增加硬件的HwBinder来实现硬件相关进程的通信。 HwBinder也是有四部分组成#xff1a;hwservermanager、server、client…    HwBinder与普通Binder是一样的,区别是前者是专门给硬件使用后者是给一般的应用程序使用为了不影响现有的binder单独增加硬件的HwBinder来实现硬件相关进程的通信。 HwBinder也是有四部分组成hwservermanager、server、clientdriver其中Driver部分与普通Binder是一样的《Android图形显示系统》对Binder的原理进行过详细的介绍这里主要介绍HwBinder与Binder不一样的地方。 服务管理进程 首先是服务管理进程由HwServiceManager服务主要流程如下 /* system/hwservicemanager/service.cpp */ int main() {     ServiceManager *manager new ServiceManager();     if (!manager-add(serviceName, manager)) {}     TokenManager *tokenManager new TokenManager();     if (!manager-add(serviceName, tokenManager)) {} spBnHwServiceManager service new BnHwServiceManager(manager); IPCThreadState::self()-setTheContextObject(service); ProcessState::self()-becomeContextManager(nullptr, nullptr);     joinRpcThreadpool(); } HwServiceManager与ServiceManager不一样的地方是hwservicemanager有Binder节点并把Binder节点通过setTheContextObject传给了驱动并且使用IPCThreadState把主线程加入到线程池来循环处理请求。意味着HwServiceManager是支持并发访问的可以同时处理多个请求 服务进程 Server的开发比较简单service.cpp的实现比较简单如下所示。 int main() {     return defaultPassthroughServiceImplementationIDemo(); } defaultPassthroughServiceImplementation的实现流程如下。 /* system\libhidl\transport\include\hidl\LegacySupport.h*/ templateclass Interface __attribute__((warn_unused_result)) status_t defaultPassthroughServiceImplementation(size_t maxThreads 1) {     return defaultPassthroughServiceImplementationInterface(default, maxThreads); } templateclass Interface __attribute__((warn_unused_result)) status_t defaultPassthroughServiceImplementation(std::string name,                                             size_t maxThreads 1) {     configureRpcThreadpool(maxThreads, true);     status_t result registerPassthroughServiceImplementationInterface(name);     joinRpcThreadpool();      return UNKNOWN_ERROR; } templateclass Interface __attribute__((warn_unused_result)) status_t registerPassthroughServiceImplementation(         std::string name default) {     spInterface service Interface::getService(name, true /* getStub */);     status_t status service-registerAsService(name);     return status; } 最后调registerPassthroughServiceImplementation来注册服务把Interface替换成IDemo得到以下。 __attribute__((warn_unused_result)) status_t registerPassthroughServiceImplementation(         std::string name default) {     spIDemo service IDemo::getService(name, true /* getStub */);     status_t status service-registerAsService(name);     return status; } 调用的是IDemo的接口getService得到IDemo节点通过registerAsServie来添加到服务管理HwServiceManager。 IDemo::getService在DemoAll.cpp实现该文件是自动生成的路径如下 out/soong/.intermediates/hardware/interfaces/demo/1.0/android.hardware.demo1.0_genc/gen/android/hardware/demo/1.0/DemoAll.cpp  ::android::spIDemo IDemo::getService(const std::string serviceName, const bool getStub) { return ::android::hardware::details::getServiceInternalBpHwDemo( serviceName, true, getStub); } getService主要通过getServiceInternal来实现继续往下 system\libhidl\transport\include\hidl\HidlTransportSupport.h template typename BpType, typename IType typename BpType::Pure,           typename std::enable_if_tstd::is_samei_tag, typename IType::_hidl_tag::value,           typename std::enable_if_tstd::is_samebphw_tag, typename BpType::_hidl_tag::value spIType getServiceInternal(const std::string instance, bool retry, bool getStub) {     using ::android::hidl::base::V1_0::IBase;     spIBase base getRawServiceInternal(IType::descriptor, instance, retry, getStub);     if (base-isRemote()) {         // getRawServiceInternal guarantees we get the proper class         return spIType(new BpType(toBinderIBase(base)));     }     return IType::castFrom(base); } system\libhidl\transport\ServiceManagement.cpp sp::android::hidl::base::V1_0::IBase getRawServiceInternal(const std::string descriptor,                                                   const std::string instance,                                                   bool retry,  bool getStub) {     const spIServiceManager pm getPassthroughServiceManager();     spIBase base pm-get(descriptor, instance).withDefault(nullptr);     return base; } spIServiceManager1_0 getPassthroughServiceManager() {     return getPassthroughServiceManager1_1(); } spIServiceManager1_1 getPassthroughServiceManager1_1() {     static spPassthroughServiceManager manager(new PassthroughServiceManager());     return manager; } struct PassthroughServiceManager : IServiceManager1_1 {     static void openLibs(         const std::string fqName,         const std::functionbool /* continue */ (void* /* handle */, const std::string /* lib */,                                                  const std::string /* sym */) eachLib) {         const std::string sym HIDL_FETCH_ ifaceName;/     }     ReturnspIBase get(const hidl_string fqName,                           const hidl_string name) override {         spIBase ret nullptr;         openLibs(fqName, [](void* handle, const std::string lib, const std::string sym) {             IBase* (*generator)(const char* name);             *(void **)(generator) dlsym(handle, sym.c_str());            ret (*generator)(name.c_str());            using ::android::hardware::details::getDescriptor;            std::string actualFqName getDescriptor(ret.get());            registerReference(actualFqName, name);         });         return ret;     } } 最终通过遍历so加载得到符号HIDL_FETCH_IDemo并调用得到Demo的对象在Demo.h已经定义 extern C IDemo* HIDL_FETCH_IDemo(const char* name);  在函数前加extern “C”才能使用dlsym 加载到该方法的地址。 下一步Server通过registerAsService把Binder注册到ServiceManager的流程实现还是在DemoAll.cpp里。 out/soong/.intermediates/hardware/interfaces/demo/1.0/android.hardware.demo1.0_genc/gen/android/hardware/demo/1.0/DemoAll.cpp ::android::status_t IDemo::registerAsService(const std::string serviceName) {     const ::android::sp::android::hidl::manager::V1_0::IServiceManager sm              ::android::hardware::defaultServiceManager();     ::android::hardware::Returnbool ret sm-add(serviceName.c_str(), this); } 这里也是通过defaultServiceManager找到ServiceManager的索引对象然后调add接口来添加Demo的对象。 system/hwservicemanager/ServieManager.cpp Returnbool ServiceManager::add(const hidl_string name, const spIBase service) {     auto ret service-interfaceChain([](const auto interfaceChain) {         for(size_t i 0; i interfaceChain.size(); i) {             const std::string fqName interfaceChain[i];             PackageInterfaceMap ifaceMap mServiceMap[fqName];             HidlService *hidlService ifaceMap.lookup(name);             if (hidlService nullptr) {                 ifaceMap.insertService(                     std::make_uniqueHidlService(fqName, name, service, pid));             } else {                 hidlService-setService(service, pid);             }             ifaceMap.sendPackageRegistrationNotification(fqName, name);         }     }); } 在HwServiceManager注册Binder的时候也是需要name的不过是通过interfaceChain来获取Demo Binder对象的name。最后把结果保存到ifaceMap里这里跟ServiceManager只保存Binder的handle也是不一样的。 Server注册服务后Client进程可以查找到Server的binder对象并调用相关的接口来向Server请求服务了 客户进程 接下来是客户进程的流程 int main() {     android::spIDemo service IDemo::getService();     service-sayHello(HIDL !!!, [](hidl_string result) {                 printf(get from server %s\n, result.c_str()); });     return 0; } Client进程主要先调IDemo::getService来得到binder对象并调其方法sayHello把请求发给Server。 Client进程也通过getService获取Demo索引对象跟Server进程获取到的Demo节点对象是不太一样的。 out/soong/.intermediates/hardware/interfaces/demo/1.0/android.hardware.demo1.0_genc_headers/gen/android/hardware/demo/1.0/IDemo.h struct IDemo : public ::android::hidl::base::V1_0::IBase {     static ::android::spIDemo getService(const std::string serviceNamedefault, bool getStubfalse); } Server进程的registerPassthroughServiceImplementation也使用过getService只不过getStub为true这里使用默认参数为false主要是getRawServiceInternal有区别。 system\libhidl\transport\ServiceManagement.cpp sp::android::hidl::base::V1_0::IBase getRawServiceInternal(const std::string descriptor,                                                              const std::string instance,                                                              bool retry, bool getStub) {     const spIServiceManager1_1 sm defaultServiceManager1_1();     for (int tries 0; !getStub (vintfHwbinder || vintfLegacy); tries) {         ReturnspIBase ret sm-get(descriptor, instance);         spIBase base ret;         return base;     } } getStub为false会从ServiceManager来查找服务。 system/hwservicemanager/ServieManager.cpp ReturnspIBase ServiceManager::get(const hidl_string hidlFqName,                                       const hidl_string hidlName) {     const std::string fqName hidlFqName;     const std::string name hidlName;     auto ifaceIt mServiceMap.find(fqName);     const PackageInterfaceMap ifaceMap ifaceIt-second;     const HidlService *hidlService ifaceMap.lookup(name);     spIBase service hidlService-getService();     return service; } Client进程是从HwManager查询回来的索引对象。原理跟普通的binder一样。只不过这里封装的比普通的Binder要复杂。 上面结合一个简单的例子介绍了HIDL的用法并解析了相关的代码HIDL基于hwbinder进行进程间通信。