ecency-mobile/ios/Pods/Folly/folly/VirtualExecutor.h
2019-05-29 14:32:35 +03:00

87 lines
2.3 KiB
C++

/*
* Copyright 2018-present Facebook, Inc.
*
* 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 <folly/DefaultKeepAliveExecutor.h>
namespace folly {
/**
* VirtualExecutor implements a light-weight view onto existing Executor.
*
* Multiple VirtualExecutors can be backed by a single Executor.
*
* VirtualExecutor's destructor blocks until all tasks scheduled through it are
* complete. Executor's destructor also blocks until all VirtualExecutors
* backed by it are released.
*/
class VirtualExecutor : public DefaultKeepAliveExecutor {
auto wrapFunc(Func f) {
class FuncAndKeepAlive {
public:
FuncAndKeepAlive(Func&& f, VirtualExecutor* executor)
: keepAlive_(getKeepAliveToken(executor)), f_(std::move(f)) {}
void operator()() {
f_();
}
private:
Executor::KeepAlive<VirtualExecutor> keepAlive_;
Func f_;
};
return FuncAndKeepAlive(std::move(f), this);
}
public:
explicit VirtualExecutor(KeepAlive<> executor)
: executor_(std::move(executor)) {
assert(!isKeepAliveDummy(executor_));
}
explicit VirtualExecutor(Executor* executor)
: VirtualExecutor(getKeepAliveToken(executor)) {}
explicit VirtualExecutor(Executor& executor)
: VirtualExecutor(getKeepAliveToken(executor)) {}
VirtualExecutor(const VirtualExecutor&) = delete;
VirtualExecutor& operator=(const VirtualExecutor&) = delete;
uint8_t getNumPriorities() const override {
return executor_->getNumPriorities();
}
void add(Func f) override {
executor_->add(wrapFunc(std::move(f)));
}
void addWithPriority(Func f, int8_t priority) override {
executor_->addWithPriority(wrapFunc(std::move(f)), priority);
}
~VirtualExecutor() override {
joinKeepAlive();
}
private:
const KeepAlive<> executor_;
};
} // namespace folly