foundationdb/flow/IThreadPool.cpp

133 lines
4.2 KiB
C++

/*
* IThreadPool.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2022 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>
// The ifndef's allow us to compile with pre-built boost. Otherwise, we get
// errors about double-defines. As of this writing, the automatically downloaded
// build of boost doesn't define these, but the pre-built version does. (The old
// prebuilt version was being silently ignored by cmake, so it's unclear when the
// compatibility divergence started)
#ifndef BOOST_SYSTEM_NO_LIB
#define BOOST_SYSTEM_NO_LIB
#endif
#ifndef BOOST_DATE_TIME_NO_LIB
#define BOOST_DATE_TIME_NO_LIB
#endif
#ifndef BOOST_REGEX_NO_LIB
#define BOOST_REGEX_NO_LIB
#endif
#include "boost/asio.hpp"
class ThreadPool final : public IThreadPool, public ReferenceCounted<ThreadPool> {
struct Thread {
ThreadPool* pool;
IThreadPoolReceiver* userObject;
THREAD_HANDLE handle; // Owned by main thread
static thread_local IThreadPoolReceiver* threadUserObject;
explicit Thread(ThreadPool* pool, IThreadPoolReceiver* userObject) : pool(pool), userObject(userObject) {}
~Thread() { ASSERT_ABORT(!userObject); }
void run() {
setThreadPriority(pool->priority());
threadUserObject = userObject;
try {
userObject->init();
while (pool->ios.run_one() && (pool->mode == Mode::Run))
;
} catch (Error& e) {
TraceEvent(SevError, "ThreadPoolError").error(e);
}
delete userObject;
userObject = nullptr;
}
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;
int stackSize;
int pri;
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 = nullptr; }
void operator()() {
Thread::dispatch(action);
action = nullptr;
}
~ActionWrapper() {
if (action) {
action->cancel();
}
}
ActionWrapper& operator=(ActionWrapper const&) = delete;
};
public:
ThreadPool(int stackSize, int pri) : dontstop(ios), mode(Run), stackSize(stackSize), pri(pri) {}
~ThreadPool() override {}
Future<Void> stop(Error const& e = success()) override {
if (mode == Shutdown)
return Void();
ReferenceCounted<ThreadPool>::addref();
ios.stop(); // doesn't work?
mode = Shutdown;
for (int i = 0; i < threads.size(); i++) {
waitThread(threads[i]->handle);
delete threads[i];
}
ReferenceCounted<ThreadPool>::delref();
return Void();
}
Future<Void> getError() const override { return Never(); } // FIXME
void addref() override { ReferenceCounted<ThreadPool>::addref(); }
void delref() override {
if (ReferenceCounted<ThreadPool>::delref_no_destroy()) {
stop();
delete this;
}
}
void addThread(IThreadPoolReceiver* userData, const char* name) override {
threads.push_back(new Thread(this, userData));
threads.back()->handle = g_network->startThread(start, threads.back(), stackSize, name);
}
void post(PThreadAction action) override { ios.post(ActionWrapper(action)); }
int priority() const { return pri; }
};
Reference<IThreadPool> createGenericThreadPool(int stackSize, int pri) {
return Reference<IThreadPool>(new ThreadPool(stackSize, pri));
}
thread_local IThreadPoolReceiver* ThreadPool::Thread::threadUserObject;