42 lines
1.6 KiB
C++
42 lines
1.6 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <folly/Executor.h>
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namespace folly {
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// `SoftRealTimeExecutor` is an executor that performs some priority-based
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// scheduling with a deadline assigned to each task. __Soft__ real-time
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// means that not every deadline is guaranteed to be met.
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class SoftRealTimeExecutor : public virtual Executor {
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void add(Func) override = 0;
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// Add a task with an assigned abstract deadline.
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//
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// NOTE: The type of `deadline` was chosen to be an integral rather than
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// a typed time point or duration (e.g., `std::chrono::time_point`) to allow
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// for flexbility. While the deadline for a task may be a time point,
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// it could also be a duration or the size of the task, which emulates
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// rate-monotonic scheduling that prioritizes small tasks. It also enables
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// for exmaple, tiered scheduling (strictly prioritizing a category of tasks)
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// by assigning the high-bit of the deadline.
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virtual void add(Func, uint64_t deadline) = 0;
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};
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} // namespace folly
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