health 2.1 implementation.

Test: VTS health 2.1 test
Bug: 137670450

Change-Id: I04ea74facbaa534eee00a51474a013db3b6eb212
diff --git a/health/utils/libhealth2impl/BinderHealth.cpp b/health/utils/libhealth2impl/BinderHealth.cpp
new file mode 100644
index 0000000..625d0e0
--- /dev/null
+++ b/health/utils/libhealth2impl/BinderHealth.cpp
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2019 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 <health2impl/BinderHealth.h>
+
+#include <android-base/logging.h>
+#include <hidl/HidlTransportSupport.h>
+#include <hwbinder/IPCThreadState.h>
+
+#include <health2impl/Callback.h>
+#include <health2impl/Health.h>
+
+using android::hardware::handleTransportPoll;
+using android::hardware::IPCThreadState;
+using android::hardware::setupTransportPolling;
+
+using android::hardware::health::V2_0::Result;
+
+namespace android {
+namespace hardware {
+namespace health {
+namespace V2_1 {
+namespace implementation {
+
+bool IsDeadObjectLogged(const Return<void>& ret) {
+    if (ret.isOk()) return false;
+    if (ret.isDeadObject()) return true;
+    LOG(ERROR) << "Cannot call healthInfoChanged* on callback: " << ret.description();
+    return false;
+}
+
+BinderHealth::BinderHealth(const std::string& name, const sp<IHealth>& impl)
+    : HalHealthLoop(name, impl) {
+    CHECK_NE(this, impl.get());
+    CHECK(!impl->isRemote());
+}
+
+//
+// Methods that handle callbacks.
+//
+
+Return<Result> BinderHealth::registerCallback(const sp<V2_0::IHealthInfoCallback>& callback) {
+    if (callback == nullptr) {
+        return Result::SUCCESS;
+    }
+
+    Callback* wrapped = nullptr;
+    {
+        std::lock_guard<decltype(callbacks_lock_)> lock(callbacks_lock_);
+        wrapped = callbacks_.emplace_back(Wrap(callback)).get();
+        // unlock
+    }
+
+    auto linkRet = callback->linkToDeath(this, 0u /* cookie */);
+    if (!linkRet.withDefault(false)) {
+        LOG(WARNING) << __func__ << "Cannot link to death: "
+                     << (linkRet.isOk() ? "linkToDeath returns false" : linkRet.description());
+        // ignore the error
+    }
+
+    getHealthInfo_2_1([&](auto res, const auto& health_info) {
+        if (res != Result::SUCCESS) {
+            LOG(ERROR) << "Cannot call getHealthInfo_2_1: " << toString(res);
+            return;
+        }
+        auto ret = wrapped->Notify(health_info);
+        if (IsDeadObjectLogged(ret)) {
+            // Remove callback reference.
+            std::lock_guard<decltype(callbacks_lock_)> lock(callbacks_lock_);
+            auto it = std::find_if(callbacks_.begin(), callbacks_.end(),
+                                   [wrapped](const auto& cb) { return cb.get() == wrapped; });
+            if (it != callbacks_.end()) {
+                callbacks_.erase(it);
+            }
+            // unlock
+        }
+    });
+
+    return Result::SUCCESS;
+}
+
+bool BinderHealth::unregisterCallbackInternal(const sp<IBase>& callback) {
+    if (callback == nullptr) {
+        return false;
+    }
+
+    bool removed = false;
+    std::lock_guard<decltype(callbacks_lock_)> lock(callbacks_lock_);
+    for (auto it = callbacks_.begin(); it != callbacks_.end();) {
+        if (interfacesEqual((*it)->Get(), callback)) {
+            it = callbacks_.erase(it);
+            removed = true;
+        } else {
+            ++it;
+        }
+    }
+    (void)callback->unlinkToDeath(this).isOk();  // ignore errors
+    return removed;
+}
+
+Return<Result> BinderHealth::update() {
+    Result result = service()->update();
+    if (result != Result::SUCCESS) return result;
+    getHealthInfo_2_1([&](auto res, const auto& health_info) {
+        if (res != Result::SUCCESS) {
+            result = res;
+            return;
+        }
+        OnHealthInfoChanged(health_info);
+    });
+    return result;
+}
+
+Return<Result> BinderHealth::unregisterCallback(const sp<V2_0::IHealthInfoCallback>& callback) {
+    return unregisterCallbackInternal(callback) ? Result::SUCCESS : Result::NOT_FOUND;
+}
+
+void BinderHealth::OnHealthInfoChanged(const HealthInfo& health_info) {
+    // Notify all callbacks
+    std::unique_lock<decltype(callbacks_lock_)> lock(callbacks_lock_);
+    for (auto it = callbacks_.begin(); it != callbacks_.end();) {
+        auto ret = (*it)->Notify(health_info);
+        if (IsDeadObjectLogged(ret)) {
+            it = callbacks_.erase(it);
+        } else {
+            ++it;
+        }
+    }
+    lock.unlock();
+
+    // adjusts uevent / wakealarm periods
+    HalHealthLoop::OnHealthInfoChanged(health_info);
+}
+
+void BinderHealth::serviceDied(uint64_t /* cookie */, const wp<IBase>& who) {
+    (void)unregisterCallbackInternal(who.promote());
+}
+
+void BinderHealth::BinderEvent(uint32_t /*epevents*/) {
+    if (binder_fd_ >= 0) {
+        handleTransportPoll(binder_fd_);
+    }
+}
+
+void BinderHealth::Init(struct healthd_config* config) {
+    // Set up epoll and get uevent / wake alarm periods
+    HalHealthLoop::Init(config);
+
+    LOG(INFO) << instance_name() << " instance initializing with healthd_config...";
+
+    binder_fd_ = setupTransportPolling();
+
+    if (binder_fd_ >= 0) {
+        auto binder_event = [](auto* health_loop, uint32_t epevents) {
+            static_cast<BinderHealth*>(health_loop)->BinderEvent(epevents);
+        };
+        if (RegisterEvent(binder_fd_, binder_event, EVENT_NO_WAKEUP_FD) != 0) {
+            PLOG(ERROR) << instance_name() << " instance: Register for binder events failed";
+        }
+    }
+
+    CHECK_EQ(registerAsService(instance_name()), android::OK)
+            << instance_name() << ": Failed to register HAL";
+
+    LOG(INFO) << instance_name() << ": Hal init done";
+}
+
+int BinderHealth::PrepareToWait(void) {
+    IPCThreadState::self()->flushCommands();
+    return HalHealthLoop::PrepareToWait();
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace health
+}  // namespace hardware
+}  // namespace android