104 lines
3.4 KiB
C++
104 lines
3.4 KiB
C++
/*
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* Copyright (c) 2018 The BitShares Blockchain, and contributors.
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*
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* The MIT License
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#pragma once
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#include <fc/thread/task.hpp>
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#include <fc/thread/thread.hpp>
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#include <fc/asio.hpp>
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namespace fc {
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namespace detail {
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class pool_impl;
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class worker_pool {
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public:
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worker_pool();
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~worker_pool();
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void post( task_base* task );
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private:
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pool_impl* my;
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};
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worker_pool& get_worker_pool();
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}
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class serial_valve {
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private:
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class ticket_guard {
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public:
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ticket_guard( boost::atomic<future<void>*>& latch );
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~ticket_guard();
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void wait_for_my_turn();
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private:
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promise<void>* my_promise;
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future<void>* ticket;
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};
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friend class ticket_guard;
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boost::atomic<future<void>*> latch;
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public:
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serial_valve();
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~serial_valve();
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/** Executes f1() then f2().
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* For any two calls do_serial(f1,f2) and do_serial(f1',f2') where
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* do_serial(f1,f2) is invoked before do_serial(f1',f2'), it is
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* guaranteed that f2' will be executed after f2 has completed. Failure
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* of either function counts as completion of both.
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* If f1 throws then f2 will not be invoked.
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*
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* @param f1 a functor to invoke
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* @param f2 a functor to invoke
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* @return the return value of f2()
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*/
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template<typename Functor1,typename Functor2>
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auto do_serial( const Functor1& f1, const Functor2& f2 ) -> decltype(f2())
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{
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ticket_guard guard( latch );
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f1();
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guard.wait_for_my_turn();
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return f2();
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}
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};
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/**
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* Calls function <code>f</code> in a separate thread and returns a future
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* that can be used to wait on the result.
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*
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* @param f the operation to perform
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*/
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template<typename Functor>
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auto do_parallel( Functor&& f, const char* desc FC_TASK_NAME_DEFAULT_ARG ) -> fc::future<decltype(f())> {
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typedef decltype(f()) Result;
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typedef typename fc::deduce<Functor>::type FunctorType;
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fc::task<Result,sizeof(FunctorType)>* tsk =
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new fc::task<Result,sizeof(FunctorType)>( fc::forward<Functor>(f), desc );
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fc::future<Result> r(fc::shared_ptr< fc::promise<Result> >(tsk,true) );
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detail::get_worker_pool().post( tsk );
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return r;
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}
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}
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