foundationdb/flow/IThreadPool.cpp

112 lines
3.4 KiB
C++

/*
* IThreadPool.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project 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
*
* 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.
*/
#include "flow/IThreadPool.h"
#include <algorithm>
#define BOOST_SYSTEM_NO_LIB
#define BOOST_DATE_TIME_NO_LIB
#define BOOST_REGEX_NO_LIB
#include "boost/asio.hpp"
#include "boost/bind.hpp"
class ThreadPool : public IThreadPool, public ReferenceCounted<ThreadPool> {
struct Thread {
ThreadPool *pool;
IThreadPoolReceiver* userObject;
Event stopped;
static thread_local IThreadPoolReceiver* threadUserObject;
explicit Thread(ThreadPool *pool, IThreadPoolReceiver *userObject) : pool(pool), userObject(userObject) {}
~Thread() { ASSERT_ABORT(!userObject); }
void run() {
deprioritizeThread();
threadUserObject = userObject;
try {
userObject->init();
while (pool->ios.run_one() && !pool->mode);
} catch (Error& e) {
TraceEvent(SevError, "ThreadPoolError").error(e);
}
delete userObject; userObject = 0;
stopped.set();
}
static void dispatch( PThreadAction action ) {
(*action)(threadUserObject);
}
};
THREAD_FUNC start( void* p ) {
((Thread*)p)->run();
THREAD_RETURN;
}
std::vector<Thread*> threads;
boost::asio::io_service ios;
boost::asio::io_service::work dontstop;
enum Mode { Run=0, Shutdown=2 };
volatile int mode;
struct ActionWrapper {
PThreadAction action;
ActionWrapper(PThreadAction action) : action(action) {}
// HACK: Boost won't use move constructors, so we just assume the last copy made is the one that will be called or cancelled
ActionWrapper(ActionWrapper const& r) : action(r.action) { const_cast<ActionWrapper&>(r).action=NULL; }
void operator()() { Thread::dispatch(action); action = NULL; }
~ActionWrapper() { if (action) { action->cancel(); } }
private:
void operator=(ActionWrapper const&);
};
public:
ThreadPool() : dontstop(ios), mode(Run) {}
~ThreadPool() {}
Future<Void> stop(Error const& e = success()) {
if (mode == Shutdown) return Void();
ReferenceCounted<ThreadPool>::addref();
ios.stop(); // doesn't work?
mode = Shutdown;
for(int i=0; i<threads.size(); i++) {
threads[i]->stopped.block();
delete threads[i];
}
ReferenceCounted<ThreadPool>::delref();
return Void();
}
virtual Future<Void> getError() { return Never(); } // FIXME
virtual void addref() { ReferenceCounted<ThreadPool>::addref(); }
virtual void delref() { if (ReferenceCounted<ThreadPool>::delref_no_destroy()) stop(); }
void addThread( IThreadPoolReceiver* userData ) {
threads.push_back(new Thread(this, userData));
startThread(start, threads.back());
}
void post( PThreadAction action ) {
ios.post( ActionWrapper( action ) );
}
};
Reference<IThreadPool> createGenericThreadPool()
{
return Reference<IThreadPool>( new ThreadPool );
}
thread_local IThreadPoolReceiver* ThreadPool::Thread::threadUserObject;