1 // Copyright 2023 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include "pw_async/context.h" 17 #include "pw_function/function.h" 18 #include "pw_status/status.h" 19 20 namespace pw::async { 21 22 /// A `TaskFunction` is a unit of work that is wrapped by a Task and executed on 23 /// a `Dispatcher`. 24 /// 25 /// `TaskFunction`s take a `Context` as their first argument. Before executing a 26 /// `Task`, the `Dispatcher` sets the pointer to itself and to the `Task` in 27 /// `Context`. 28 /// 29 /// `TaskFunction`s take a `Status` as their second argument. When a Task is 30 /// running as normal, |status| is `PW_STATUS_OK`. If a `Task` will not be able 31 /// to run as scheduled, the `Dispatcher` will still invoke the `TaskFunction` 32 /// with |status| `PW_STATUS_CANCELLED`. This provides an opportunity to reclaim 33 /// resources held by the Task. 34 /// 35 /// A `Task` will not run as scheduled if, for example, it is still waiting when 36 /// the `Dispatcher` shuts down. 37 using TaskFunction = Function<void(Context&, Status)>; 38 39 } // namespace pw::async 40