| /* |
| * 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. |
| */ |
| |
| #ifndef android_hardware_automotive_vehicle_aidl_impl_vhal_include_PendingRequestPool_H_ |
| #define android_hardware_automotive_vehicle_aidl_impl_vhal_include_PendingRequestPool_H_ |
| |
| #include <android-base/result.h> |
| #include <android-base/thread_annotations.h> |
| |
| #include <atomic> |
| #include <list> |
| #include <mutex> |
| #include <thread> |
| #include <unordered_map> |
| #include <unordered_set> |
| |
| namespace android { |
| namespace hardware { |
| namespace automotive { |
| namespace vehicle { |
| |
| // A thread-safe pending request pool that tracks whether each request has timed-out. |
| class PendingRequestPool final { |
| public: |
| using TimeoutCallbackFunc = std::function<void(const std::unordered_set<int64_t>&)>; |
| |
| explicit PendingRequestPool(int64_t timeoutInSec); |
| |
| ~PendingRequestPool(); |
| |
| // Adds a list of requests to the request pool. |
| // The clientId is the key for all the requests. It could be a number or an address to a data |
| // structure that represents a client. The caller must maintain this data structure. |
| // All the request IDs must be unique for one client, if any of the requestIds is duplicate with |
| // any pending request IDs for the client, this function returns error and no requests would be |
| // added. Otherwise, they would be added to the request pool. |
| // The callback would be called if requests are not finished within {@code mTimeoutInNano} |
| // seconds. |
| android::base::Result<void> addRequests(const void* clientId, |
| const std::unordered_set<int64_t>& requestIds, |
| std::shared_ptr<TimeoutCallbackFunc> callback); |
| |
| // Checks whether the request is currently pending. |
| bool isRequestPending(const void* clientId, int64_t requestId) const; |
| |
| // Tries to mark the requests as finished and remove them from the pool if the request is |
| // currently pending. Returns the list of request that is pending and has been finished |
| // successfully. This function would try to finish any valid requestIds even though some of the |
| // requestIds are not valid. |
| std::unordered_set<int64_t> tryFinishRequests(const void* clientId, |
| const std::unordered_set<int64_t>& requestIds); |
| |
| // Returns how many pending requests in the pool, for testing purpose. |
| size_t countPendingRequests(const void* clientId) const; |
| |
| private: |
| // The maximum number of pending requests allowed per client. If exceeds this number, adding |
| // more requests would fail. This is to prevent spamming from client. |
| static constexpr size_t MAX_PENDING_REQUEST_PER_CLIENT = 10000; |
| |
| struct PendingRequest { |
| std::unordered_set<int64_t> requestIds; |
| int64_t timeoutTimestamp; |
| std::shared_ptr<TimeoutCallbackFunc> callback; |
| }; |
| |
| int64_t mTimeoutInNano; |
| mutable std::mutex mLock; |
| std::unordered_map<const void*, std::list<PendingRequest>> mPendingRequestsByClient |
| GUARDED_BY(mLock); |
| std::thread mThread; |
| std::atomic<bool> mThreadStop = false; |
| std::condition_variable mCv; |
| std::mutex mCvLock; |
| |
| bool isRequestPendingLocked(const void* clientId, int64_t requestId) const REQUIRES(mLock); |
| |
| // Checks whether the requests in the pool has timed-out, run periodically in a separate thread. |
| void checkTimeout(); |
| }; |
| |
| } // namespace vehicle |
| } // namespace automotive |
| } // namespace hardware |
| } // namespace android |
| |
| #endif // android_hardware_automotive_vehicle_aidl_impl_vhal_include_PendingRequestPool_H_ |