hal interface
?IDeviceFactory openDevice得到IDevice, IDevice openInput/outputStream得到IStream
?android.hardware.audio.service
存在形式
hardware/interfaces/audio/common/all-versions/default/service/android.hardware.audio.service.rc
service vendor.audio-hal /vendor/bin/hw/android.hardware.audio.service
? ? class hal
? ? user audioserver
hardware/interfaces/audio/common/all-versions/default/service/Android.bp
cc_binary {
? ? name: "android.hardware.audio.service",
? ? init_rc: ["android.hardware.audio.service.rc"],
? ? vendor: true,
? ? srcs: ["service.cpp"],
}
在同一个进程启动了多个service
int main(int /* argc */, char* /* argv */ []) {
? ? ::android::ProcessState::initWithDriver("/dev/vndbinder");
? ? // start a threadpool for vndbinder interactions
? ? ::android::ProcessState::self()->startThreadPool();
? ? const std::vector<InterfacesList> mandatoryInterfaces = {
? ? ? ? {
? ? ? ? ? ? "Audio Core API",
? ? ? ? ? ? "android.hardware.audio@6.0::IDevicesFactory",
? ? ? ? ? ? "android.hardware.audio@5.0::IDevicesFactory",
? ? ? ? ? ? "android.hardware.audio@4.0::IDevicesFactory",
? ? ? ? ? ? "android.hardware.audio@2.0::IDevicesFactory"
? ? ? ? },
? ? ? ? {
? ? ? ? ? ? "Audio Effect API",
? ? ? ? ? ? "android.hardware.audio.effect@6.0::IEffectsFactory",
? ? ? ? ? ? "android.hardware.audio.effect@5.0::IEffectsFactory",
? ? ? ? ? ? "android.hardware.audio.effect@4.0::IEffectsFactory",
? ? ? ? ? ? "android.hardware.audio.effect@2.0::IEffectsFactory",
? ? ? ? }
? ? };
? ? const std::vector<InterfacesList> optionalInterfaces = {
? ? ? ? {
? ? ? ? ? ? "Soundtrigger API",
? ? ? ? ? ? "android.hardware.soundtrigger@2.3::ISoundTriggerHw",
? ? ? ? ? ? "android.hardware.soundtrigger@2.2::ISoundTriggerHw",
? ? ? ? ? ? "android.hardware.soundtrigger@2.1::ISoundTriggerHw",
? ? ? ? ? ? "android.hardware.soundtrigger@2.0::ISoundTriggerHw",
? ? ? ? },
? ? ? ? {
? ? ? ? ? ? "Bluetooth Audio API",
? ? ? ? ? ? "android.hardware.bluetooth.audio@2.0::IBluetoothAudioProvidersFactory"
? ? ? ? },
? ? ? ? // remove the old HIDL when Bluetooth Audio Hal V2 has offloading supported
? ? ? ? {
? ? ? ? ? ? "Bluetooth Audio Offload API",
? ? ? ? ? ? "android.hardware.bluetooth.a2dp@1.0::IBluetoothAudioOffload"
? ? ? ? }
? ? };
? ? for (const auto& listIter : mandatoryInterfaces) {
? ? ? ? auto iter = listIter.begin();
? ? ? ? const std::string& interfaceFamilyName = *iter++;
? ? ? ? LOG_ALWAYS_FATAL_IF(!registerPassthroughServiceImplementations(iter, listIter.end()),
? ? ? ? ? ? ? ? ? ? ? ? ? ? "Could not register %s", interfaceFamilyName.c_str());
? ? }
? ? for (const auto& listIter : optionalInterfaces) {
? ? ? ? auto iter = listIter.begin();
? ? ? ? const std::string& interfaceFamilyName = *iter++;
? ? ? ? ALOGW_IF(!registerPassthroughServiceImplementations(iter, listIter.end()),
? ? ? ? ? ? ? ? ?"Could not register %s", interfaceFamilyName.c_str());
? ? }
? ? joinRpcThreadpool();
}
?
registerPassthroughServiceImplementation的实现
https://www.programminghunter.com/article/7441427492/
https://blog.csdn.net/u013928208/article/details/81667162
HIDL_FETCH_IDevicesFactory是怎样别调到的？
registerPassthroughServiceImplementation的实现
system/libhidl/transport/LegacySupport.cpp
registerPassthroughServiceImplementation ->?
getRawServiceInternal ->?
getPassthroughServiceManager ->
(system/libhidl/transport/ServiceManagement.cpp)
IServiceManager1_1::openLibs {
? ? ? ? const std::string prefix = packageAndVersion + "-impl";
? ? ? ? const std::string sym = "HIDL_FETCH_" + ifaceName;
}
hardware/interfaces/audio/effect/all-versions/default/Android.bp
cc_library_shared {
? ? name: "android.hardware.audio.effect@6.0-impl",
? ? defaults: ["android.hardware.audio.effect-impl_default"],
? ? shared_libs: [
? ? ? ? "android.hardware.audio.common@6.0",
? ? ? ? "android.hardware.audio.common@6.0-util",
? ? ? ? "android.hardware.audio.effect@6.0",
? ? ],
}
hardware/interfaces/audio/core/all-versions/default/DevicesFactory.cpp
IDevicesFactory* HIDL_FETCH_IDevicesFactory(const char* name) {
? ? return strcmp(name, "default") == 0 ? new DevicesFactory() : nullptr;
}
DevicesFactoryHalHybrid::openDevice 的实现
status_t DevicesFactoryHalHybrid::openDevice(const char *name, sp<DeviceHalInterface> *device) {
? ? if (mHidlFactory != 0 && strcmp(AUDIO_HARDWARE_MODULE_ID_A2DP, name) != 0 &&
? ? ? ? strcmp(AUDIO_HARDWARE_MODULE_ID_HEARING_AID, name) != 0) {
? ? ? ? return mHidlFactory->openDevice(name, device);
? ? }
? ? return mLocalFactory->openDevice(name, device);
}
/**
?* List of known audio HAL modules. This is the base name of the audio HAL
?* library composed of the "audio." prefix, one of the base names below and
?* a suffix specific to the device.
?* e.g: audio.primary.goldfish.so or audio.a2dp.default.so
?*
?* The same module names are used in audio policy configuration files.
?*/
#define AUDIO_HARDWARE_MODULE_ID_PRIMARY "primary"
#define AUDIO_HARDWARE_MODULE_ID_A2DP "a2dp"
#define AUDIO_HARDWARE_MODULE_ID_USB "usb"
#define AUDIO_HARDWARE_MODULE_ID_REMOTE_SUBMIX "r_submix"
#define AUDIO_HARDWARE_MODULE_ID_CODEC_OFFLOAD "codec_offload"
#define AUDIO_HARDWARE_MODULE_ID_STUB "stub"
#define AUDIO_HARDWARE_MODULE_ID_HEARING_AID "hearing_aid"
#define AUDIO_HARDWARE_MODULE_ID_MSD "msd"
mHidlFactory->openDevice(name, device)的实现
status_t DevicesFactoryHalHidl::openDevice(const char *name, sp<DeviceHalInterface> *device) {
? ? auto factories = copyDeviceFactories();
? ? if (factories.empty()) return NO_INIT;
? ? status_t status;
? ? auto hidlId = idFromHal(name, &status);
? ? if (status != OK) return status;
? ? Result retval = Result::NOT_INITIALIZED;
? ? for (const auto& factory : factories) {
? ? ? ? Return<void> ret = factory->openDevice(
? ? ? ? ? ? ? ? hidlId,
? ? ? ? ? ? ? ? [&](Result r, const sp<IDevice>& result) {
? ? ? ? ? ? ? ? ? ? retval = r;
? ? ? ? ? ? ? ? ? ? if (retval == Result::OK) { //在回调函数里 hidl service 把生成的 IDevice作为参数
?? ??? ??? ??? ??? ??? ?//调用new DeviceHalHidl(IDevice)
? ? ? ? ? ? ? ? ? ? ? ? *device = new DeviceHalHidl(result);
? ? ? ? ? ? ? ? ? ? }
? ? ? ? ? ? ? ? });
? ? }
? ? ALOGW("The specified device name is not recognized: \"%s\"", name);
? ? return BAD_VALUE;
}
hardware/interfaces/audio/core/all-versions/default/DevicesFactory.cpp
template <class DeviceShim, class Callback>
Return<void> DevicesFactory::openDevice(const char* moduleName, Callback _hidl_cb) {
? ? audio_hw_device_t* halDevice;
? ? sp<DeviceShim> result;
? ? int halStatus = loadAudioInterface(moduleName, &halDevice);
? ? if (halStatus == OK) {
? ? ? ? result = new DeviceShim(halDevice);
? ? ? ? retval = Result::OK;
? ? }
? ? _hidl_cb(retval, result);
? ? return Void();
}
hardware device的框架
int DevicesFactory::loadAudioInterface(const char* if_name, audio_hw_device_t** dev) {
? ? const hw_module_t* mod;
? ? int rc;
? ? rc = hw_get_module_by_class(AUDIO_HARDWARE_MODULE_ID: "audio", if_name, &mod);
? ? rc = audio_hw_device_open(mod, dev);
? ? return OK;
}
?