- 1Totem Movie Player是一套在類Unix操作系統上運行的多媒體播放器，也是Ubuntu系統的預設影片播放器_中文幕播放
- 2【Java进阶】线程池之无限线程数 - Executors.newCachedThreadPool() ，创建无限线程数线程池
- 3Spring Boot官方文档指南_springboot 官方文档
- 4JavaScript UTF-8编码转换_js uint8array to utf8strig
- 5CVE-2022-21882 Win32k内核提权漏洞深入分析_hmvalidatehandle
- 6地方微信群分享小程序源码,自带流量主独立版_加群小程序源码
- 7毕业设计-基于机器视觉的车型识别系统_车型识别项目
- 8win10 安装 Langchain-Chatchat 避坑指南（2023年9月18日v0.2.4版本，包含全部下载内容！）_langchain-chatchat 配置gpu
- 9鸿蒙应用开发培训笔记03：Ability 设计与开发_ability开发
- 10Alfred安装与使用_mac alfred 4 时间戳
Android O HIDL框架_android hidl框架
赞
踩
HIDL简介
Android O开始，Google为了将framework和HAL层分割开来，使得framework可以独立于HAL层更新，设计了HIDL。有了HIDL，HAL模块可以以一个独立的Service启动，framework可以通过Binder来和HAL模块进行通信，厂家实现的HAL模块将会被放到设备的/vendor目录下。
HIDL分为两种模式：Passthrough模式和Binderized模式。Passthrough模式是为了兼容Android O以前打开HAL的模式：首次调用该HAL接口时会调用hw_get_module打开HAL模块。但是Passthrough模式仅能用于C++层，Java层值能使用Binderized模式。而Binderized模式会启动一个Service进程，里面已经加载好HAL的so库，framework直接通过Binder和该HAL service通信。
HIDL用法
系统定义的所有的.hal接口，都是通过hidl-gen工具转换成对应的代码。hidl-gen源码路径：system/tools/hidl，是在ubuntu上可执行的二进制文件。
使用方法（可执行文件位于源码的out/host/linux-x86/bin/hidl-gen）：`
usage: ./host/linux-x86/bin/hidl-gen [-p <root path>] -o <output path> -L <language> (-r <interface root>)+ [-t] fqname+ -h: Prints this menu. -L <language>: The following options are available: check : Parses the interface to see if valid but doesn't write any files. c++ : (internal) (deprecated) Generates C++ interface files for talking to HIDL interfaces. c++-headers : (internal) Generates C++ headers for interface files for talking to HIDL interfaces. c++-sources : (internal) Generates C++ sources for interface files for talking to HIDL interfaces. export-header : Generates a header file from @export enumerations to help maintain legacy code. c++-impl : Generates boilerplate implementation of a hidl interface in C++ (for convenience). c++-impl-headers: c++-impl but headers only c++-impl-sources: c++-impl but sources only java : (internal) Generates Java library for talking to HIDL interfaces in Java. java-constants : (internal) Like export-header but for Java (always created by -Lmakefile if @export exists). vts : (internal) Generates vts proto files for use in vtsd. makefile : (internal) Generates makefiles for -Ljava and -Ljava-constants. androidbp : (internal) Generates Soong bp files for -Lc++-headers and -Lc++-sources. androidbp-impl : Generates boilerplate bp files for implementation created with -Lc++-impl. hash : Prints hashes of interface in `current.txt` format to standard out. -o <output path>: Location to output files. -p <root path>: Android build root, defaults to $ANDROID_BUILD_TOP or pwd. -r <package:path root>: E.g., android.hardware:hardware/interfaces. -t: generate build scripts (Android.bp) for tests.
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
BootControl模块编译过程
在Android的frameworks/hardware（对应包前缀android.frameworks.），hardware/interfaces（对应包前缀android.hardware.），system/libhidl（对应包前缀android.hidl.），system/hardware/interfaces（对应包前缀android.system.）目录下均放置有update-makefiles.sh脚本，执行这个脚本就会在上述目录下找到*.hal文件的位置，自动生成对应的mk（只在hardware/interfaces才生成）和bp文件。Google设计使用hidl-gen工具编译*.hal文件来自动生成对应的java，cpp，.h等文件，通过*.hal来描述所有的HIDL接口和类型。在对应的mk和bp文件可以看到具体的hidl-gen生成规则和输出路径。本文将以IBootControl.hal为例讲HIDL的框架，不再讨论这个HAL的具体功能。使用hidl-gen工具后，在out目录生成的文件主要有IBootControl.java（Java层对HIDL的封装），BpHwBootControl.h（Binder Bp端头文件），BnHwBootControl.h（Binder Bn端头文件），BsBootControl.h（Passthrough模式的封装），BootControlAll.cpp（包含Binder Bp端函数实现，Binder Bn端函数实现，BsBootControl部分函数实现还有IBootControl的getService实现等）。
可以看到*.hal文件的内容很简单，package指明了这个IBootControl.hal文件所属的包，interface声明了IBootControl.hal的接口。所有的IXXX.hal的接口均隐式继承自IBase.hal的接口，类比Java所有类都继承自java.lang.Object。IBase.hal包含了一些体现HAL接口共性的接口，类比Java所有的实例对象都能使用Obejct类的notify()方法。
IBootControl.hal和types.hal编译自动生成出来的cpp，.h等文件会被放到android.hardware.boot@1.0.so里面，java文件会被放到android.hidl.base-V1.0-java.jar动态库和android.hardware.boot-V1.0-java-static静态库里面。这些so和jar会被放在设备的/system下面，然而default目录下service.cpp则被编译成android.hardware.boot@1.0-impl.so，跟HAL具体实现的so一起被放在/vendor下。Bootcontol模块的目录结构如下：
├── 1.0 │ ├── Android.bp │ ├── Android.mk │ ├── default │ │ ├── android.hardware.boot@1.0-service.rc │ │ ├── Android.mk │ │ ├── BootControl.cpp │ │ ├── BootControl.h │ │ └── service.cpp │ ├── IBootControl.hal │ ├── types.hal │ └── vts │ ├── Android.bp │ ├── Android.mk │ └── functional │ ├── Android.bp │ └── VtsHalBootV1_0TargetTest.cpp └── Android.bp
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
hardware/interfaces/boot/1.0/IBootControl.hal
package android.hardware.boot@1.0; /** * The Boot Control HAL is designed to allow for managing sets of redundant * partitions, called slots, that can be booted from independently. Slots * are sets of partitions whose names differ only by a given suffix. * They are identified here by a 0 indexed number and associated with their * suffix, which is appended to the base name for any particular partition * to find the one associated with that slot. * The primary use of this set up is to allow for background updates while * the device is running, and to provide a fallback in the event that the * update fails. */ interface IBootControl { /** * getNumberSlots() returns the number of available slots. * For instance, a system with a single set of partitions must return * 1, a system with A/B must return 2, A/B/C -> 3 and so on. A system with * less than two slots doesn't support background updates, for example if * running from a virtual machine with only one copy of each partition for the * purpose of testing. */ getNumberSlots() generates (uint32_t numSlots); ... getSuffix(Slot slot) generates (string slotSuffix); };
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
hardware/interfaces/boot/1.0/types.hal
package android.hardware.boot@1.0; /** * A command result encapsulating whether the command succeeded and * an error string. */ struct CommandResult { bool success; string errMsg; }; /** * An identifier for a slot number. */ typedef uint32_t Slot; /** * A result encapsulating whether a function returned true, false or * failed due to an invalid slot number */ enum BoolResult : int32_t { FALSE = 0, TRUE = 1, INVALID_SLOT = -1 };
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
再看看同级目录下的Android.bp和Android.m k。
以types.hal和IBootControl.hal作为一个名为"android.hardware.boot@1.0_hal"的filegroup，通过genrule定义的hidl-gen规则生成相应的文件。hidl-gen的-L参数为“c++source”时，生成的是cpp文件；-L参数为“c+±headers”时，生成的是头文件；-o参数为genDir的变量，一般位于./soong/.intermediates下面，根据编译出来的文件类型个模块所处的源码位置有所不同，例如IBootControl.h位于./soong/.intermediates/hardware/interfaces/boot/1.0/android.hardware.boot@1.0_genc++_headers/gen/android/hardware/boot/1.0/IBootControl.h，BootControlAll.cpp位于./soong/.intermediates/hardware/interfaces/boot/1.0/android.hardware.boot@1.0_genc++/gen/android/hardware/boot/1.0/BootControlAll.cpp，“hardware/interfaces/boot/1.0”这部分为源码的位置，“android.hardware.boot@1.0_gencxxx”由模块的全限定名加生成文件类型确定，剩下的部分则可以参考genrule规则的out选项。
最后的cc_library选项将之前genrule产生的头文件和源文件编译成一个so。
Android.m k则用于编译出对应的Java动态库，静态库和Java文件，不再详细叙述。
hardware/interfaces/boot/1.0/Android.bp
// This file is autogenerated by hidl-gen. Do not edit manually. filegroup { name: "android.hardware.boot@1.0_hal", srcs: [ "types.hal", "IBootControl.hal", ], } genrule { name: "android.hardware.boot@1.0_genc++", tools: ["hidl-gen"], cmd: "$(location hidl-gen) -o $(genDir) -Lc++-sources -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport android.hardware.boot@1.0", srcs: [ ":android.hardware.boot@1.0_hal", ], out: [ "android/hardware/boot/1.0/types.cpp", "android/hardware/boot/1.0/BootControlAll.cpp", ], } genrule { name: "android.hardware.boot@1.0_genc++_headers", tools: ["hidl-gen"], cmd: "$(location hidl-gen) -o $(genDir) -Lc++-headers -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport android.hardware.boot@1.0", srcs: [ ":android.hardware.boot@1.0_hal", ], out: [ "android/hardware/boot/1.0/types.h", "android/hardware/boot/1.0/hwtypes.h", "android/hardware/boot/1.0/IBootControl.h", "android/hardware/boot/1.0/IHwBootControl.h", "android/hardware/boot/1.0/BnHwBootControl.h", "android/hardware/boot/1.0/BpHwBootControl.h", "android/hardware/boot/1.0/BsBootControl.h", ], } cc_library { name: "android.hardware.boot@1.0", defaults: ["hidl-module-defaults"], generated_sources: ["android.hardware.boot@1.0_genc++"], generated_headers: ["android.hardware.boot@1.0_genc++_headers"], export_generated_headers: ["android.hardware.boot@1.0_genc++_headers"], vendor_available: true, vndk: { enabled: true, }, shared_libs: [ "libhidlbase", "libhidltransport", "libhwbinder", "liblog", "libutils", "libcutils", ], export_shared_lib_headers: [ "libhidlbase", "libhidltransport", "libhwbinder", "libutils", ], }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
在default文件夹下，有一个rc文件，用来启动HAL服务进程的：
hardware/interfaces/boot/1.0/default/android.hardware.boot@1.0-service.rc
service boot-hal-1-0 /vendor/bin/hw/android.hardware.boot@1.0-service
class early_hal
user root
group root
- 1
- 2
- 3
- 4
再看看这个服务的来历。可以看到service.cpp被编译成android.hardware.boot@1.0-service，其main函数也是该服务的入口。
hardware/interfaces/boot/1.0/default
LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := android.hardware.boot@1.0-impl LOCAL_MODULE_RELATIVE_PATH := hw LOCAL_PROPRIETARY_MODULE := true LOCAL_SRC_FILES := \ BootControl.cpp \ LOCAL_SHARED_LIBRARIES := \ liblog \ libhidlbase \ libhidltransport \ libhardware \ libutils \ android.hardware.boot@1.0 \ include $(BUILD_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE_RELATIVE_PATH := hw LOCAL_PROPRIETARY_MODULE := true LOCAL_MODULE := android.hardware.boot@1.0-service LOCAL_INIT_RC := android.hardware.boot@1.0-service.rc LOCAL_SRC_FILES := \ service.cpp LOCAL_SHARED_LIBRARIES := \ liblog \ libhardware \ libhidlbase \ libhidltransport \ libutils \ android.hardware.boot@1.0 \ include $(BUILD_EXECUTABLE)
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
启动服务：
hardware/interfaces/boot/1.0/default/service.cpp
int main (int /* argc */, char * /* argv */ []) {
return defaultPassthroughServiceImplementation<IBootControl>();
}
- 1
- 2
- 3
- 4
首先是调用IBootControl::getService获取服务，这时候会首次加载底层HAL的so，然后调用IBootControl::registerAsService向HwServiceManager注册服务，这样，framework就可以通过Binder跟android.hardware.boot@1.0-service这个厂商Service进程进行通信了。
system/libhidl/transport/include/hidl/LegacySupport.h
template<class Interface>
__attribute__((warn_unused_result))
status_t defaultPassthroughServiceImplementation(std::string name,
size_t maxThreads = 1) {
configureRpcThreadpool(maxThreads, true);
status_t result = registerPassthroughServiceImplementation<Interface>(name);
if (result != OK) {
return result;
}
joinRpcThreadpool();
return 0;
}
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
system/libhidl/transport/include/hidl/LegacySupport.h
template<class Interface> __attribute__((warn_unused_result)) status_t registerPassthroughServiceImplementation( std::string name = "default") { sp<Interface> service = Interface::getService(name, true /* getStub */); if (service == nullptr) { ALOGE("Could not get passthrough implementation for %s/%s.", Interface::descriptor, name.c_str()); return EXIT_FAILURE; } LOG_FATAL_IF(service->isRemote(), "Implementation of %s/%s is remote!", Interface::descriptor, name.c_str()); status_t status = service->registerAsService(name); if (status == OK) { ALOGI("Registration complete for %s/%s.", Interface::descriptor, name.c_str()); } else { ALOGE("Could not register service %s/%s (%d).", Interface::descriptor, name.c_str(), status); } return status; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
out/soong/.intermediates/hardware/interfaces/boot/1.0/android.hardware.boot@1.0_genc++/gen/android/hardware/boot/1.0/BootControlAll.cpp
::android::status_t IBootControl::registerAsService(const std::string &serviceName) {
::android::hardware::details::onRegistration("android.hardware.boot@1.0", "IBootControl", serviceName);
const ::android::sp<::android::hidl::manager::V1_0::IServiceManager> sm
= ::android::hardware::defaultServiceManager();
if (sm == nullptr) {
return ::android::INVALID_OPERATION;
}
::android::hardware::Return<bool> ret = sm->add(serviceName.c_str(), this);
return ret.isOk() && ret ? ::android::OK : ::android::UNKNOWN_ERROR;
}
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
ProcessState::self()->getContextObject(NULL))会返回一个跟HwServiceManager的BpBinder，然后使用fromBinder将其转换为一个BpHwServiceManager对象。接着和以前AIDL的方式一样，调用IServiceManager::add添加服务。
HIDL框架有几个函数要注意一下：fromBinder接受一个Binder对象参数，如果该参数是Bp端的Binder对象，就会返回对应的BpHwXXXX对象；如果是Bn端的Binder对象，就会返回对应的BnHwXXXX对象的_hidl_mImpl成员。toBinder接受一个IXXXX接口对象参数，如果该参数是Bp端的Binder对象，就会返回内置的IBinder对象；如果是Bn端的Binder对象，’就返回对应的BnHwXXXX对象。可以看到，BpHwXXXX并不直接继承自IBinder，但是其拥有的mImpl成员就是一个IBinder对象。BnHwXXXX直接继承自IBinder，但是不继承自所有HAL节后的父类IBase，所以只能用IBase类型的_hidl_mImpl成员实现IXXXX接口。
system/libhidl/transport/ServiceManagement.cpp
sp<IServiceManager1_0> defaultServiceManager() { return defaultServiceManager1_1(); } sp<IServiceManager1_1> defaultServiceManager1_1() { { AutoMutex _l(details::gDefaultServiceManagerLock); if (details::gDefaultServiceManager != NULL) { return details::gDefaultServiceManager; } if (access("/dev/hwbinder", F_OK|R_OK|W_OK) != 0) { // HwBinder not available on this device or not accessible to // this process. return nullptr; } waitForHwServiceManager(); while (details::gDefaultServiceManager == NULL) { details::gDefaultServiceManager = fromBinder<IServiceManager1_1, BpHwServiceManager, BnHwServiceManager>( ProcessState::self()->getContextObject(NULL)); if (details::gDefaultServiceManager == NULL) { LOG(ERROR) << "Waited for hwservicemanager, but got nullptr."; sleep(1); } } } return details::gDefaultServiceManager; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
获取服务IBootControl::getService
在C++层，我们只需调用IXXX::getService便能获取到对应HAL的功能。
值得注意的是，我们在启动BootControl服务时调用IBootControl::getService的第二个参数getStub参数为true，这意味着启动BootControl的时候使用的是Passthrough模式，这既是启动HAL服务的函数被命名为defaultPassthroughServiceImplementation的原因。目测除了首次启动HAL服务，其他情况下
getStub参数都是false，例如应用程序获取HAL服务时。
out/soong/.intermediates/hardware/interfaces/boot/1.0/android.hardware.boot@1.0_genc++/gen/android/hardware/boot/1.0/BootControlAll.cpp
// static ::android::sp<IBootControl> IBootControl::getService(const std::string &serviceName, const bool getStub) { using ::android::hardware::defaultServiceManager; using ::android::hardware::details::waitForHwService; using ::android::hardware::getPassthroughServiceManager; using ::android::hardware::Return; using ::android::sp; using Transport = ::android::hidl::manager::V1_0::IServiceManager::Transport; sp<IBootControl> iface = nullptr; const sp<::android::hidl::manager::V1_0::IServiceManager> sm = defaultServiceManager(); if (sm == nullptr) { ALOGE("getService: defaultServiceManager() is null"); return nullptr; } Return<Transport> transportRet = sm->getTransport(IBootControl::descriptor, serviceName); if (!transportRet.isOk()) { ALOGE("getService: defaultServiceManager()->getTransport returns %s", transportRet.description().c_str()); return nullptr; } Transport transport = transportRet; const bool vintfHwbinder = (transport == Transport::HWBINDER); const bool vintfPassthru = (transport == Transport::PASSTHROUGH); #ifdef __ANDROID_TREBLE__ #ifdef __ANDROID_DEBUGGABLE__ const char* env = std::getenv("TREBLE_TESTING_OVERRIDE"); const bool trebleTestingOverride = env && !strcmp(env, "true"); const bool vintfLegacy = (transport == Transport::EMPTY) && trebleTestingOverride; #else // __ANDROID_TREBLE__ but not __ANDROID_DEBUGGABLE__ const bool trebleTestingOverride = false; const bool vintfLegacy = false; #endif // __ANDROID_DEBUGGABLE__ #else // not __ANDROID_TREBLE__ const char* env = std::getenv("TREBLE_TESTING_OVERRIDE"); const bool trebleTestingOverride = env && !strcmp(env, "true"); const bool vintfLegacy = (transport == Transport::EMPTY); #endif // __ANDROID_TREBLE__ for (int tries = 0; !getStub && (vintfHwbinder || (vintfLegacy && tries == 0)); tries++) { if (tries > 1) { ALOGI("getService: Will do try %d for %s/%s in 1s...", tries, IBootControl::descriptor, serviceName.c_str()); sleep(1); } if (vintfHwbinder && tries > 0) { waitForHwService(IBootControl::descriptor, serviceName); } Return<sp<::android::hidl::base::V1_0::IBase>> ret = sm->get(IBootControl::descriptor, serviceName); if (!ret.isOk()) { ALOGE("IBootControl: defaultServiceManager()->get returns %s", ret.description().c_str()); break; } sp<::android::hidl::base::V1_0::IBase> base = ret; if (base == nullptr) { if (tries > 0) { ALOGW("IBootControl: found null hwbinder interface"); }continue; } Return<sp<IBootControl>> castRet = IBootControl::castFrom(base, true /* emitError */); if (!castRet.isOk()) { if (castRet.isDeadObject()) { ALOGW("IBootControl: found dead hwbinder service"); continue; } else { ALOGW("IBootControl: cannot call into hwbinder service: %s; No permission? Check for selinux denials.", castRet.description().c_str()); break; } } iface = castRet; if (iface == nullptr) { ALOGW("IBootControl: received incompatible service; bug in hwservicemanager?"); break; } return iface; } if (getStub || vintfPassthru || vintfLegacy) { const sp<::android::hidl::manager::V1_0::IServiceManager> pm = getPassthroughServiceManager(); if (pm != nullptr) { Return<sp<::android::hidl::base::V1_0::IBase>> ret = pm->get(IBootControl::descriptor, serviceName); if (ret.isOk()) { sp<::android::hidl::base::V1_0::IBase> baseInterface = ret; if (baseInterface != nullptr) { iface = IBootControl::castFrom(baseInterface); if (!getStub || trebleTestingOverride) { iface = new BsBootControl(iface); } } } } } return iface; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
- 92
- 93
- 94
- 95
- 96
- 97
- 98
- 99
- 100
defaultServiceManager返回一个BpHwServiceManager对象，getTransport会决定获取服务是通过Passthrough模式还是Binderized模式。getTransport接受两个参数，第一个是HAL服务的全限定名，本文中是android.hardware.boot@1.0::IBootControl；第二个是instance名，通过先后匹配/system/manifest.xml和/vendor/manifest.xml来决定使用哪种方式。
manifest.xml的每一项如下所示。android.hardware.boot对应< name>项，1.0对应< version>项，IBootControl对应< interface>项里面的< name>项，启动服务的函数defaultPassthroughServiceImplementation的第一个参数，如果没有，默认参数为"default"。getTransport会按上述的项去寻找符合要求的项，根据< transport>的值决定返回值，其中hwbinder是Binderized模式，passthrough是PassThrough模式。
/system/manifest.xml
<hal format="hidl">
<name>android.hardware.graphics.composer</name>
<transport>hwbinder</transport>
<version>2.1</version>
<interface>
<name>IComposer</name>
<instance>vr</instance>
</interface>
</hal>
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
回到IBootControl::getService函数。下面几个参数将决定走的是Binderized模式还是Passthrough模式：1.getStub参数，目前我看到只在首次启动服务时是true，在其他情况为false；2.vintfHwbinder在getTransport函数返回的是Binderized模式时为true；3.vintfPassthru在getTransport函数返回的是PassThrough模式为true；4.vintfLegacy在Android Treble架构下且未开启__ANDROID_DEBUGGABLE__宏时为false，即默认为false。下面情况均按vintfLegacy为false来说明。
当getStub参数为false且vintfHwbinder为true时，使用Binderized模式；当getStub参数为true或者vintfPassthru为true时，使用PassThrough模式。也就是说这个android.hardware.boot@1.0-service服务时以PassThrough模式启动的，但是跟android.hardware.boot@1.0-service服务通信时用的是Binderized模式。
PassThrough模式
可见PassThrough模式时通过PassthroughServiceManager进行的。
system/libhidl/transport/ServiceManagement.cpp
sp<IServiceManager1_0> getPassthroughServiceManager() {
return getPassthroughServiceManager1_1();
}
sp<IServiceManager1_1> getPassthroughServiceManager1_1() {
static sp<PassthroughServiceManager> manager(new PassthroughServiceManager());
return manager;
}
- 1
- 2
- 3
- 4
- 5
- 6
- 7
PassthroughServiceManager::get函数的任务是使用dlopen打开对应的*-impl的so库，本文中是android.hardware.boot@1.0-impl.so，找到其中HIDL_FETCH_XXX函数执行并返回执行后的返回值，本文中是BootControl.cpp中的HIDL_FETCH_IBootControl函数。
system/libhidl/transport/ServiceManagement.cpp
struct PassthroughServiceManager : IServiceManager1_1 { static void openLibs(const std::string& fqName, std::function<bool /* continue */(void* /* handle */, const std::string& /* lib */, const std::string& /* sym */)> eachLib) { //fqName looks like android.hardware.foo@1.0::IFoo size_t idx = fqName.find("::"); if (idx == std::string::npos || idx + strlen("::") + 1 >= fqName.size()) { LOG(ERROR) << "Invalid interface name passthrough lookup: " << fqName; return; } std::string packageAndVersion = fqName.substr(0, idx); std::string ifaceName = fqName.substr(idx + strlen("::")); const std::string prefix = packageAndVersion + "-impl"; const std::string sym = "HIDL_FETCH_" + ifaceName; const int dlMode = RTLD_LAZY; void *handle = nullptr; dlerror(); // clear std::vector<std::string> paths = {HAL_LIBRARY_PATH_ODM, HAL_LIBRARY_PATH_VENDOR, HAL_LIBRARY_PATH_VNDK_SP, HAL_LIBRARY_PATH_SYSTEM}; #ifdef LIBHIDL_TARGET_DEBUGGABLE const char* env = std::getenv("TREBLE_TESTING_OVERRIDE"); const bool trebleTestingOverride = env && !strcmp(env, "true"); if (trebleTestingOverride) { const char* vtsRootPath = std::getenv("VTS_ROOT_PATH"); if (vtsRootPath && strlen(vtsRootPath) > 0) { const std::string halLibraryPathVtsOverride = std::string(vtsRootPath) + HAL_LIBRARY_PATH_SYSTEM; paths.push_back(halLibraryPathVtsOverride); } } #endif for (const std::string& path : paths) { std::vector<std::string> libs = search(path, prefix, ".so"); for (const std::string &lib : libs) { const std::string fullPath = path + lib; if (path != HAL_LIBRARY_PATH_SYSTEM) { handle = android_load_sphal_library(fullPath.c_str(), dlMode); } else { handle = dlopen(fullPath.c_str(), dlMode); } if (handle == nullptr) { const char* error = dlerror(); LOG(ERROR) << "Failed to dlopen " << lib << ": " << (error == nullptr ? "unknown error" : error); continue; } if (!eachLib(handle, lib, sym)) { return; } } } } Return<sp<IBase>> get(const hidl_string& fqName, const hidl_string& name) override { sp<IBase> 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()); if(!generator) { const char* error = dlerror(); LOG(ERROR) << "Passthrough lookup opened " << lib << " but could not find symbol " << sym << ": " << (error == nullptr ? "unknown error" : error); dlclose(handle); return true; } ret = (*generator)(name.c_str()); if (ret == nullptr) { dlclose(handle); return true; // this module doesn't provide this instance name } registerReference(fqName, name); return false; }); return ret; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
- 92
- 93
HIDL_FETCH_IBootControl的作用就是hw_get_module加载对应HAL的实现了，最后用一个BootControl对象封装好HAL的实现并将其返回。BootControl继承自IBootControl。IBootControl::getService在最后用该BootControl对象为参数构建一个BsBootControl返回。
hardware/interfaces/boot/1.0/default/BootControl.cpp
IBootControl* HIDL_FETCH_IBootControl(const char* /* hal */) {
int ret = 0;
boot_control_module_t* module = NULL;
hw_module_t **hwm = reinterpret_cast<hw_module_t**>(&module);
ret = hw_get_module(BOOT_CONTROL_HARDWARE_MODULE_ID, const_cast<const hw_module_t**>(hwm));
if (ret)
{
ALOGE("hw_get_module %s failed: %d", BOOT_CONTROL_HARDWARE_MODULE_ID, ret);
return nullptr;
}
module->init(module);
return new BootControl(module);
}
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
Binderized模式
Binderized模式就是通过BpHwServiceManager::get来获取HAL服务。
out/soong/.intermediates/system/libhidl/transport/manager/1.1/android.hidl.manager@1.1_genc++/gen/android/hidl/manager/1.1/ServiceManagerAll.cpp
::android::hardware::Return<::android::sp<::android::hidl::base::V1_0::IBase>> BpHwServiceManager::get(const ::android::hardware::hidl_string& fqName, const ::android::hardware::hidl_string& name){
::android::hardware::Return<::android::sp<::android::hidl::base::V1_0::IBase>> _hidl_out = ::android::hidl::manager::V1_0::BpHwServiceManager::_hidl_get(this, this, fqName, name);
return _hidl_out;
}
- 1
- 2
- 3
- 4
- 5
在这里便可以看到明显的Binder框架了：Bp端的transact对应Bn端的onTransact，进而调用到BnHwServiceManager::_hidl_get。
out/soong/.intermediates/system/libhidl/transport/manager/1.1/android.hidl.manager@1.1_genc++/gen/android/hidl/manager/1.1/ServiceManagerAll.cpp
// Methods from IServiceManager follow. ::android::hardware::Return<::android::sp<::android::hidl::base::V1_0::IBase>> BpHwServiceManager::_hidl_get(::android::hardware::IInterface *_hidl_this, ::android::hardware::details::HidlInstrumentor *_hidl_this_instrumentor, const ::android::hardware::hidl_string& fqName, const ::android::hardware::hidl_string& name) { #ifdef __ANDROID_DEBUGGABLE__ bool mEnableInstrumentation = _hidl_this_instrumentor->isInstrumentationEnabled(); const auto &mInstrumentationCallbacks = _hidl_this_instrumentor->getInstrumentationCallbacks(); #else (void) _hidl_this_instrumentor; #endif // __ANDROID_DEBUGGABLE__ atrace_begin(ATRACE_TAG_HAL, "HIDL::IServiceManager::get::client"); #ifdef __ANDROID_DEBUGGABLE__ if (UNLIKELY(mEnableInstrumentation)) { std::vector<void *> _hidl_args; _hidl_args.push_back((void *)&fqName); _hidl_args.push_back((void *)&name); for (const auto &callback: mInstrumentationCallbacks) { callback(InstrumentationEvent::CLIENT_API_ENTRY, "android.hidl.manager", "1.0", "IServiceManager", "get", &_hidl_args); } } #endif // __ANDROID_DEBUGGABLE__ ::android::hardware::Parcel _hidl_data; ::android::hardware::Parcel _hidl_reply; ::android::status_t _hidl_err; ::android::hardware::Status _hidl_status; ::android::sp<::android::hidl::base::V1_0::IBase> _hidl_out_service; _hidl_err = _hidl_data.writeInterfaceToken(BpHwServiceManager::descriptor); if (_hidl_err != ::android::OK) { goto _hidl_error; } size_t _hidl_fqName_parent; _hidl_err = _hidl_data.writeBuffer(&fqName, sizeof(fqName), &_hidl_fqName_parent); if (_hidl_err != ::android::OK) { goto _hidl_error; } _hidl_err = ::android::hardware::writeEmbeddedToParcel( fqName, &_hidl_data, _hidl_fqName_parent, 0 /* parentOffset */); if (_hidl_err != ::android::OK) { goto _hidl_error; } size_t _hidl_name_parent; _hidl_err = _hidl_data.writeBuffer(&name, sizeof(name), &_hidl_name_parent); if (_hidl_err != ::android::OK) { goto _hidl_error; } _hidl_err = ::android::hardware::writeEmbeddedToParcel( name, &_hidl_data, _hidl_name_parent, 0 /* parentOffset */); if (_hidl_err != ::android::OK) { goto _hidl_error; } _hidl_err = ::android::hardware::IInterface::asBinder(_hidl_this)->transact(1 /* get */, _hidl_data, &_hidl_reply); if (_hidl_err != ::android::OK) { goto _hidl_error; } _hidl_err = ::android::hardware::readFromParcel(&_hidl_status, _hidl_reply); if (_hidl_err != ::android::OK) { goto _hidl_error; } if (!_hidl_status.isOk()) { return _hidl_status; } { ::android::sp<::android::hardware::IBinder> _hidl__hidl_out_service_binder; _hidl_err = _hidl_reply.readNullableStrongBinder(&_hidl__hidl_out_service_binder); if (_hidl_err != ::android::OK) { goto _hidl_error; } _hidl_out_service = ::android::hardware::fromBinder<::android::hidl::base::V1_0::IBase,::android::hidl::base::V1_0::BpHwBase,::android::hidl::base::V1_0::BnHwBase>(_hidl__hidl_out_service_binder); } atrace_end(ATRACE_TAG_HAL); #ifdef __ANDROID_DEBUGGABLE__ if (UNLIKELY(mEnableInstrumentation)) { std::vector<void *> _hidl_args; _hidl_args.push_back((void *)&_hidl_out_service); for (const auto &callback: mInstrumentationCallbacks) { callback(InstrumentationEvent::CLIENT_API_EXIT, "android.hidl.manager", "1.0", "IServiceManager", "get", &_hidl_args); } } #endif // __ANDROID_DEBUGGABLE__ _hidl_status.setFromStatusT(_hidl_err); return ::android::hardware::Return<::android::sp<::android::hidl::base::V1_0::IBase>>(_hidl_out_service); _hidl_error: _hidl_status.setFromStatusT(_hidl_err); return ::android::hardware::Return<::android::sp<::android::hidl::base::V1_0::IBase>>(_hidl_status); }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
之前提到，BnHwXXXX的_hidl_mImpl为对应的IXXXX接口实现。BnHwServiceManager::_hidl_get调用了其_hidl_mImpl的get函数。
out/soong/.intermediates/system/libhidl/transport/manager/1.1/android.hidl.manager@1.1_genc++/gen/android/hidl/manager/1.1/ServiceManagerAll.cpp
// Methods from IServiceManager follow. ::android::status_t BnHwServiceManager::_hidl_get( ::android::hidl::base::V1_0::BnHwBase* _hidl_this, const ::android::hardware::Parcel &_hidl_data, ::android::hardware::Parcel *_hidl_reply, TransactCallback _hidl_cb) { #ifdef __ANDROID_DEBUGGABLE__ bool mEnableInstrumentation = _hidl_this->isInstrumentationEnabled(); const auto &mInstrumentationCallbacks = _hidl_this->getInstrumentationCallbacks(); #endif // __ANDROID_DEBUGGABLE__ ::android::status_t _hidl_err = ::android::OK; if (!_hidl_data.enforceInterface(BnHwServiceManager::Pure::descriptor)) { _hidl_err = ::android::BAD_TYPE; return _hidl_err; } const ::android::hardware::hidl_string* fqName; const ::android::hardware::hidl_string* name; size_t _hidl_fqName_parent; _hidl_err = _hidl_data.readBuffer(sizeof(*fqName), &_hidl_fqName_parent, reinterpret_cast<const void **>(&fqName)); if (_hidl_err != ::android::OK) { return _hidl_err; } _hidl_err = ::android::hardware::readEmbeddedFromParcel( const_cast<::android::hardware::hidl_string &>(*fqName), _hidl_data, _hidl_fqName_parent, 0 /* parentOffset */); if (_hidl_err != ::android::OK) { return _hidl_err; } size_t _hidl_name_parent; _hidl_err = _hidl_data.readBuffer(sizeof(*name), &_hidl_name_parent, reinterpret_cast<const void **>(&name)); if (_hidl_err != ::android::OK) { return _hidl_err; } _hidl_err = ::android::hardware::readEmbeddedFromParcel( const_cast<::android::hardware::hidl_string &>(*name), _hidl_data, _hidl_name_parent, 0 /* parentOffset */); if (_hidl_err != ::android::OK) { return _hidl_err; } atrace_begin(ATRACE_TAG_HAL, "HIDL::IServiceManager::get::server"); #ifdef __ANDROID_DEBUGGABLE__ if (UNLIKELY(mEnableInstrumentation)) { std::vector<void *> _hidl_args; _hidl_args.push_back((void *)fqName); _hidl_args.push_back((void *)name); for (const auto &callback: mInstrumentationCallbacks) { callback(InstrumentationEvent::SERVER_API_ENTRY, "android.hidl.manager", "1.0", "IServiceManager", "get", &_hidl_args); } } #endif // __ANDROID_DEBUGGABLE__ ::android::sp<::android::hidl::base::V1_0::IBase> _hidl_out_service = static_cast<BnHwServiceManager*>(_hidl_this)->_hidl_mImpl->get(*fqName, *name); ::android::hardware::writeToParcel(::android::hardware::Status::ok(), _hidl_reply); if (_hidl_out_service == nullptr) { _hidl_err = _hidl_reply->writeStrongBinder(nullptr); } else { ::android::sp<::android::hardware::IBinder> _hidl_binder = ::android::hardware::toBinder< ::android::hidl::base::V1_0::IBase>(_hidl_out_service); if (_hidl_binder.get() != nullptr) { _hidl_err = _hidl_reply->writeStrongBinder(_hidl_binder); } else { _hidl_err = ::android::UNKNOWN_ERROR; } } /* _hidl_err ignored! */ atrace_end(ATRACE_TAG_HAL); #ifdef __ANDROID_DEBUGGABLE__ if (UNLIKELY(mEnableInstrumentation)) { std::vector<void *> _hidl_args; _hidl_args.push_back((void *)&_hidl_out_service); for (const auto &callback: mInstrumentationCallbacks) { callback(InstrumentationEvent::SERVER_API_EXIT, "android.hidl.manager", "1.0", "IServiceManager", "get", &_hidl_args); } } #endif // __ANDROID_DEBUGGABLE__ _hidl_cb(*_hidl_reply); return _hidl_err; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
BnHwServiceManager的_hidl_mImpl来自ServiceManager，这个ServiceManager区别于Android O以前的ServiceManager，这是一个HAL服务。所有通过Binderized模式添加或者获取服务都是通过ServiceManager进行的。
system/hwservicemanager/service.cpp
int main() { configureRpcThreadpool(1, true /* callerWillJoin */); ServiceManager *manager = new ServiceManager(); if (!manager->add(serviceName, manager)) { ALOGE("Failed to register hwservicemanager with itself."); } TokenManager *tokenManager = new TokenManager(); if (!manager->add(serviceName, tokenManager)) { ALOGE("Failed to register ITokenManager with hwservicemanager."); } sp<Looper> looper(Looper::prepare(0 /* opts */)); int binder_fd = -1; IPCThreadState::self()->setupPolling(&binder_fd); if (binder_fd < 0) { ALOGE("Failed to aquire binder FD. Aborting..."); return -1; } // Flush after setupPolling(), to make sure the binder driver // knows about this thread handling commands. IPCThreadState::self()->flushCommands(); sp<BinderCallback> cb(new BinderCallback); if (looper->addFd(binder_fd, Looper::POLL_CALLBACK, Looper::EVENT_INPUT, cb, nullptr) != 1) { ALOGE("Failed to add hwbinder FD to Looper. Aborting..."); return -1; } // Tell IPCThreadState we're the service manager sp<BnHwServiceManager> service = new BnHwServiceManager(manager); IPCThreadState::self()->setTheContextObject(service); // Then tell binder kernel ioctl(binder_fd, BINDER_SET_CONTEXT_MGR, 0); // Only enable FIFO inheritance for hwbinder // FIXME: remove define when in the kernel #define BINDER_SET_INHERIT_FIFO_PRIO _IO('b', 10) int rc = ioctl(binder_fd, BINDER_SET_INHERIT_FIFO_PRIO); if (rc) { ALOGE("BINDER_SET_INHERIT_FIFO_PRIO failed with error %d\n", rc); } rc = property_set("hwservicemanager.ready", "true"); if (rc) { ALOGE("Failed to set \"hwservicemanager.ready\" (error %d). "\ "HAL services will not start!\n", rc); } while (true) { looper->pollAll(-1 /* timeoutMillis */); } return 0; }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
ServiceManager服务的添加和获取是通过内部的mServiceMap的map数据结构进行的，这个map键值为服务的全限定名，对应的是PackageInterfaceMap对象。其中PackageInterfaceMap又包含一个InstanceMap的map数据结构，其以服务的instance名为键值，对应的是HidlService对象。HidlService对象包含了IXXXX的实现，可以通过HidlService::getService函数获取。
所以，跟Android O以前的ServiceManager不同的是，以往的ServiceManager会将服务信息保存到内核中，而HAL的ServiceManager把HAL服务的信息保存在map数据结构中。
可以看到如果IBootControl::getService使用的是PassThrough模式，返回的是一个BsBootControl，也就是跟HAL服务位于同一进程，跟Android O之前的调用方式兼容；如果使用的是Binderized，返回的是一个BpHwBootControl，具备跨进程通信的能力。
system/hwservicemanager/ServiceManager.cpp
// Methods from ::android::hidl::manager::V1_0::IServiceManager follow. Return<sp<IBase>> ServiceManager::get(const hidl_string& fqName, const hidl_string& name) { pid_t pid = IPCThreadState::self()->getCallingPid(); if (!mAcl.canGet(fqName, pid)) { return nullptr; } auto ifaceIt = mServiceMap.find(fqName); if (ifaceIt == mServiceMap.end()) { return nullptr; } const PackageInterfaceMap &ifaceMap = ifaceIt->second; const HidlService *hidlService = ifaceMap.lookup(name); if (hidlService == nullptr) { return nullptr; } return hidlService->getService(); }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
Java层的Binderized模式
Java层获取HAL服务是通过HwBinder#getService获取的。这是个native方法。
可以看到getTransport返回的不是Binderized模式时，便会抛出异常。而当getTransport返回的是Binderized模式时，在后续的流程就会走BpHwServiceManager::get函数。所以说，Java要使用HIDL的前提是这个HAL服务是使用Binderized模式的（PassThrough模式不支持Java）。
frameworks/base/core/jni/android_os_HwBinder.cpp
static jobject JHwBinder_native_getService( JNIEnv *env, jclass /* clazzObj */, jstring ifaceNameObj, jstring serviceNameObj) { using ::android::hidl::base::V1_0::IBase; using ::android::hidl::manager::V1_0::IServiceManager; if (ifaceNameObj == NULL) { jniThrowException(env, "java/lang/NullPointerException", NULL); return NULL; } if (serviceNameObj == NULL) { jniThrowException(env, "java/lang/NullPointerException", NULL); return NULL; } auto manager = hardware::defaultServiceManager(); if (manager == nullptr) { LOG(ERROR) << "Could not get hwservicemanager."; signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */); return NULL; } const char *ifaceNameCStr = env->GetStringUTFChars(ifaceNameObj, NULL); if (ifaceNameCStr == NULL) { return NULL; // XXX exception already pending? } std::string ifaceName(ifaceNameCStr); env->ReleaseStringUTFChars(ifaceNameObj, ifaceNameCStr); ::android::hardware::hidl_string ifaceNameHStr; ifaceNameHStr.setToExternal(ifaceName.c_str(), ifaceName.size()); const char *serviceNameCStr = env->GetStringUTFChars(serviceNameObj, NULL); if (serviceNameCStr == NULL) { return NULL; // XXX exception already pending? } std::string serviceName(serviceNameCStr); env->ReleaseStringUTFChars(serviceNameObj, serviceNameCStr); ::android::hardware::hidl_string serviceNameHStr; serviceNameHStr.setToExternal(serviceName.c_str(), serviceName.size()); LOG(INFO) << "Looking for service " << ifaceName << "/" << serviceName; Return<IServiceManager::Transport> transportRet = manager->getTransport(ifaceNameHStr, serviceNameHStr); if (!transportRet.isOk()) { signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */); return NULL; } IServiceManager::Transport transport = transportRet; #ifdef __ANDROID_TREBLE__ #ifdef __ANDROID_DEBUGGABLE__ const char* testingOverride = std::getenv("TREBLE_TESTING_OVERRIDE"); const bool vintfLegacy = (transport == IServiceManager::Transport::EMPTY) && testingOverride && !strcmp(testingOverride, "true"); #else // __ANDROID_TREBLE__ but not __ANDROID_DEBUGGABLE__ const bool vintfLegacy = false; #endif // __ANDROID_DEBUGGABLE__ #else // not __ANDROID_TREBLE__ const bool vintfLegacy = (transport == IServiceManager::Transport::EMPTY); #endif // __ANDROID_TREBLE__"; if (transport != IServiceManager::Transport::HWBINDER && !vintfLegacy) { LOG(ERROR) << "service " << ifaceName << " declares transport method " << toString(transport) << " but framework expects hwbinder."; signalExceptionForError(env, NAME_NOT_FOUND, true /* canThrowRemoteException */); return NULL; } Return<sp<hidl::base::V1_0::IBase>> ret = manager->get(ifaceNameHStr, serviceNameHStr); if (!ret.isOk()) { signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */); return NULL; } sp<hardware::IBinder> service = hardware::toBinder<hidl::base::V1_0::IBase>(ret); if (service == NULL) { signalExceptionForError(env, NAME_NOT_FOUND); return NULL; } LOG(INFO) << "Starting thread pool."; ::android::hardware::ProcessState::self()->startThreadPool(); return JHwRemoteBinder::NewObject(env, service); }
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
- 92
- 93
- 94
- 95
- 96
- 97
