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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <hidl/HidlLazyUtils.h>
#include <hidl/HidlTransportSupport.h>
#include <android-base/logging.h>
#include <android/hidl/manager/1.2/IClientCallback.h>
#include <android/hidl/manager/1.2/IServiceManager.h>
namespace android {
namespace hardware {
namespace details {
using ::android::hidl::base::V1_0::IBase;
class ClientCounterCallback : public ::android::hidl::manager::V1_2::IClientCallback {
public:
ClientCounterCallback() : mNumConnectedServices(0) {}
bool addRegisteredService(const sp<IBase>& service, const std::string& name);
protected:
Return<void> onClients(const sp<IBase>& service, bool clients) override;
private:
/**
* Registers or re-registers services. Returns whether successful.
*/
bool registerService(const sp<IBase>& service, const std::string& name);
/**
* Unregisters all services that we can. If we can't unregister all, re-register other
* services.
*/
void tryShutdown();
/**
* Counter of the number of services that currently have at least one client.
*/
size_t mNumConnectedServices;
struct Service {
sp<IBase> service;
std::string name;
};
/**
* Number of services that have been registered.
*/
std::vector<Service> mRegisteredServices;
};
class LazyServiceRegistrarImpl {
public:
LazyServiceRegistrarImpl() : mClientCallback(new ClientCounterCallback) {}
status_t registerService(const sp<::android::hidl::base::V1_0::IBase>& service,
const std::string& name);
private:
sp<ClientCounterCallback> mClientCallback;
};
bool ClientCounterCallback::addRegisteredService(const sp<IBase>& service,
const std::string& name) {
bool success = registerService(service, name);
if (success) {
mRegisteredServices.push_back({service, name});
}
return success;
}
bool ClientCounterCallback::registerService(const sp<IBase>& service, const std::string& name) {
auto manager = hardware::defaultServiceManager1_2();
const std::string descriptor = getDescriptor(service.get());
LOG(INFO) << "Registering HAL: " << descriptor << " with name: " << name;
status_t res = android::hardware::details::registerAsServiceInternal(service, name);
if (res != android::OK) {
LOG(ERROR) << "Failed to register as service.";
return false;
}
bool ret = manager->registerClientCallback(getDescriptor(service.get()), name, service, this);
if (!ret) {
LOG(ERROR) << "Failed to add client callback.";
return false;
}
return true;
}
/**
* onClients is oneway, so no need to worry about multi-threading. Note that this means multiple
* invocations could occur on different threads however.
*/
Return<void> ClientCounterCallback::onClients(const sp<::android::hidl::base::V1_0::IBase>& service,
bool clients) {
if (clients) {
mNumConnectedServices++;
} else {
mNumConnectedServices--;
}
LOG(INFO) << "Process has " << mNumConnectedServices << " (of " << mRegisteredServices.size()
<< " available) client(s) in use after notification " << getDescriptor(service.get())
<< " has clients: " << clients;
if (mNumConnectedServices == 0) {
tryShutdown();
}
return Status::ok();
}
void ClientCounterCallback::tryShutdown() {
LOG(INFO) << "Trying to exit HAL. No clients in use for any service in process.";
auto manager = hardware::defaultServiceManager1_2();
auto unRegisterIt = mRegisteredServices.begin();
for (; unRegisterIt != mRegisteredServices.end(); ++unRegisterIt) {
auto& entry = (*unRegisterIt);
const std::string descriptor = getDescriptor(entry.service.get());
bool success = manager->tryUnregister(descriptor, entry.name, entry.service);
if (!success) {
LOG(INFO) << "Failed to unregister HAL " << descriptor << "/" << entry.name;
break;
}
}
if (unRegisterIt == mRegisteredServices.end()) {
LOG(INFO) << "Unregistered all clients and exiting";
exit(EXIT_SUCCESS);
}
for (auto reRegisterIt = mRegisteredServices.begin(); reRegisterIt != unRegisterIt;
reRegisterIt++) {
auto& entry = (*reRegisterIt);
// re-register entry
if (!registerService(entry.service, entry.name)) {
// Must restart. Otherwise, clients will never be able to get ahold of this service.
LOG(FATAL) << "Bad state: could not re-register " << getDescriptor(entry.service.get());
}
}
}
status_t LazyServiceRegistrarImpl::registerService(
const sp<::android::hidl::base::V1_0::IBase>& service, const std::string& name) {
if (!mClientCallback->addRegisteredService(service, name)) {
return ::android::UNKNOWN_ERROR;
}
return ::android::OK;
}
} // namespace details
LazyServiceRegistrar::LazyServiceRegistrar() {
mImpl = std::make_shared<details::LazyServiceRegistrarImpl>();
}
LazyServiceRegistrar& LazyServiceRegistrar::getInstance() {
static auto registrarInstance = new LazyServiceRegistrar();
return *registrarInstance;
}
status_t LazyServiceRegistrar::registerService(
const sp<::android::hidl::base::V1_0::IBase>& service, const std::string& name) {
return mImpl->registerService(service, name);
}
} // namespace hardware
} // namespace android
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