1 files changed, 112 insertions, 0 deletions
diff --git a/neuralnetworks/aidl/utils/src/ProtectCallback.cpp b/neuralnetworks/aidl/utils/src/ProtectCallback.cpp
new file mode 100644
index 0000000000..124641cbb8
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/ProtectCallback.cpp
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2021 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 "ProtectCallback.h"
+
+#include <android-base/logging.h>
+#include <android-base/scopeguard.h>
+#include <android-base/thread_annotations.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_interface_utils.h>
+#include <nnapi/Result.h>
+#include <nnapi/hal/ProtectCallback.h>
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <vector>
+
+#include "Utils.h"
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+void DeathMonitor::serviceDied() {
+    std::lock_guard guard(mMutex);
+    std::for_each(mObjects.begin(), mObjects.end(),
+                  [](hal::utils::IProtectedCallback* killable) { killable->notifyAsDeadObject(); });
+}
+
+void DeathMonitor::serviceDied(void* cookie) {
+    auto deathMonitor = static_cast<DeathMonitor*>(cookie);
+    deathMonitor->serviceDied();
+}
+
+void DeathMonitor::add(hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    std::lock_guard guard(mMutex);
+    mObjects.push_back(killable);
+}
+
+void DeathMonitor::remove(hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    std::lock_guard guard(mMutex);
+    const auto removedIter = std::remove(mObjects.begin(), mObjects.end(), killable);
+    mObjects.erase(removedIter);
+}
+
+nn::GeneralResult<DeathHandler> DeathHandler::create(std::shared_ptr<ndk::ICInterface> object) {
+    if (object == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "utils::DeathHandler::create must have non-null object";
+    }
+    auto deathMonitor = std::make_shared<DeathMonitor>();
+    auto deathRecipient = ndk::ScopedAIBinder_DeathRecipient(
+            AIBinder_DeathRecipient_new(DeathMonitor::serviceDied));
+
+    // If passed a local binder, AIBinder_linkToDeath will do nothing and return
+    // STATUS_INVALID_OPERATION. We ignore this case because we only use local binders in tests
+    // where this is not an error.
+    if (object->isRemote()) {
+        const auto ret = ndk::ScopedAStatus::fromStatus(AIBinder_linkToDeath(
+                object->asBinder().get(), deathRecipient.get(), deathMonitor.get()));
+        HANDLE_ASTATUS(ret) << "AIBinder_linkToDeath failed";
+    }
+
+    return DeathHandler(std::move(object), std::move(deathRecipient), std::move(deathMonitor));
+}
+
+DeathHandler::DeathHandler(std::shared_ptr<ndk::ICInterface> object,
+                           ndk::ScopedAIBinder_DeathRecipient deathRecipient,
+                           std::shared_ptr<DeathMonitor> deathMonitor)
+    : kObject(std::move(object)),
+      kDeathRecipient(std::move(deathRecipient)),
+      kDeathMonitor(std::move(deathMonitor)) {
+    CHECK(kObject != nullptr);
+    CHECK(kDeathRecipient.get() != nullptr);
+    CHECK(kDeathMonitor != nullptr);
+}
+
+DeathHandler::~DeathHandler() {
+    if (kObject != nullptr && kDeathRecipient.get() != nullptr && kDeathMonitor != nullptr) {
+        const auto ret = ndk::ScopedAStatus::fromStatus(AIBinder_unlinkToDeath(
+                kObject->asBinder().get(), kDeathRecipient.get(), kDeathMonitor.get()));
+        const auto maybeSuccess = handleTransportError(ret);
+        if (!maybeSuccess.ok()) {
+            LOG(ERROR) << maybeSuccess.error().message;
+        }
+    }
+}
+
+[[nodiscard]] ::android::base::ScopeGuard<DeathHandler::Cleanup> DeathHandler::protectCallback(
+        hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    kDeathMonitor->add(killable);
+    return ::android::base::make_scope_guard(
+            [deathMonitor = kDeathMonitor, killable] { deathMonitor->remove(killable); });
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils