| // Copyright 2023 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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 "pw_async/heap_dispatcher.h" |
| |
| #include "pw_async/task.h" |
| #include "pw_result/result.h" |
| |
| namespace pw::async { |
| |
| namespace { |
| |
| // TODO: b/277793223 - Optimize to avoid double virtual indirection and double |
| // allocation. In situations in which pw::Function is large enough and the |
| // captures are small enough, we could eliminate this by reshaping the task as |
| // just a pw::Function. |
| struct TaskAndFunction { |
| static Result<TaskAndFunction*> New(TaskFunction&& task) { |
| // std::nothrow causes new to return a nullptr on failure instead of |
| // throwing. |
| TaskAndFunction* t = new (std::nothrow) TaskAndFunction(); |
| if (!t) { |
| return Status::ResourceExhausted(); |
| } |
| t->func = std::move(task); |
| |
| // Closure captures must not include references, as that would be UB due to |
| // the `delete` at the end of the function. See |
| // https://reviews.llvm.org/D48239. |
| t->task.set_function([t](Context& ctx, Status status) { |
| t->func(ctx, status); |
| |
| // Delete must appear at the very end of this closure to avoid |
| // use-after-free of captures or Context.task. |
| delete t; |
| }); |
| |
| return t; |
| } |
| Task task; |
| TaskFunction func; |
| }; |
| } // namespace |
| |
| Status HeapDispatcher::PostAt(TaskFunction&& task_func, |
| chrono::SystemClock::time_point time) { |
| Result<TaskAndFunction*> result = TaskAndFunction::New(std::move(task_func)); |
| if (!result.ok()) { |
| return result.status(); |
| } |
| dispatcher_.PostAt((*result)->task, time); |
| return Status(); |
| } |
| |
| } // namespace pw::async |