xref: /aosp_15_r20/external/pigweed/pw_async/public/pw_async/task.h (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1 // Copyright 2022 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 <optional>
17 
18 #include "pw_async/context.h"
19 #include "pw_async/task_function.h"
20 #include "pw_async_backend/task.h"
21 
22 namespace pw::async {
23 
24 namespace test {
25 class FakeDispatcher;
26 }
27 
28 /// A `Task` represents a unit of work (`TaskFunction`) that can be executed on
29 /// a `Dispatcher`. To support various `Dispatcher` backends, it wraps a
30 /// `backend::NativeTask`, which contains backend-specific state and methods.
31 class Task final {
32  public:
33   /// The default constructor creates a `Task` without a function.
34   /// `set_function()` must be called before posting the `Task`.
Task()35   Task() : native_type_(*this) {}
36 
37   /// Constructs a Task that calls `f` when executed on a `Dispatcher`.
Task(TaskFunction && f)38   explicit Task(TaskFunction&& f) : native_type_(*this, std::move(f)) {}
39 
40   Task(const Task&) = delete;
41   Task& operator=(const Task&) = delete;
42   Task(Task&&) = delete;
43   Task& operator=(Task&&) = delete;
44 
45   /// Configure the `TaskFunction` after construction. This MUST NOT be called
46   /// while this `Task` is pending in a `Dispatcher`.
set_function(TaskFunction && f)47   void set_function(TaskFunction&& f) {
48     native_type_.set_function(std::move(f));
49   }
50 
51   /// Executes this task.
operator()52   void operator()(Context& ctx, Status status) { native_type_(ctx, status); }
53 
54   /// Returns the inner `NativeTask` containing backend-specific state. Only
55   /// `Dispatcher` backends or non-portable code should call these methods!
native_type()56   backend::NativeTask& native_type() { return native_type_; }
native_type()57   const backend::NativeTask& native_type() const { return native_type_; }
58 
59  private:
60   backend::NativeTask native_type_;
61 };
62 
63 }  // namespace pw::async
64