| /* |
| * Copyright 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. |
| */ |
| |
| #pragma once |
| |
| #include <chrono> |
| #include <vector> |
| |
| #include <poll.h> |
| |
| /* An interface for pollable classes. |
| */ |
| class Pollable { |
| public: |
| using Clock = std::chrono::steady_clock; |
| using Timestamp = Clock::time_point; |
| virtual ~Pollable() = default; |
| |
| /* Get the poll data for the next poll loop. The implementation can place |
| * as many fds as needed in |fds|. |
| */ |
| virtual void getPollData(std::vector<pollfd>* fds) const = 0; |
| /* Get the timeout for the next poll loop. This should be a timestamp |
| * indicating when the timeout should be triggered. Note that this may |
| * be called at any time and any number of times for a poll loop so the |
| * deadline should not be adjusted in this call, a set deadline should |
| * just be returned. Note specifically that if a call to onReadAvailable |
| * modifies the deadline the timeout for the previous timestamp might not |
| * fire as the poller will check the timestamp AFTER onReadAvailable is |
| * called. |
| */ |
| virtual Timestamp getTimeout() const = 0; |
| /* Called when there is data available to read on an fd associated with |
| * the pollable. |fd| indicates which fd to read from. If the call returns |
| * false the poller will exit its poll loop with a return code of |status|. |
| */ |
| virtual bool onReadAvailable(int fd, int* status) = 0; |
| /* Called when an fd associated with the pollable is closed. |fd| indicates |
| * which fd was closed. If the call returns false the poller will exit its |
| * poll loop with a return code of |status|. |
| */ |
| virtual bool onClose(int fd, int* status) = 0; |
| /* Called when the timeout returned by getPollData has been reached. If |
| * the call returns false the poller will exit its poll loop with a return |
| * code of |status|. |
| */ |
| virtual bool onTimeout(Timestamp now, int* status) = 0; |
| }; |
| |