monero/src/common/threadpool.h
moneromooo-monero 27522aaa12
core_tests: reset thread pool between tests
Avoids a DB error (leading to an assert) where a thread uses
a read txn previously created with an environment that was
since closed and reopened. While this usually works since
BlockchainLMDB renews txns if it detects the environment has
changed, this will not work if objects end up being allocated
at the same address as the previous instance, leading to stale
data usage.

Thanks hyc for the LMDB debugging.
2019-11-10 12:58:49 +00:00

99 lines
3.1 KiB
C++

// Copyright (c) 2017-2019, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#pragma once
#include <boost/thread/condition_variable.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/thread.hpp>
#include <cstddef>
#include <functional>
#include <utility>
#include <vector>
#include <stdexcept>
namespace tools
{
//! A global thread pool
class threadpool
{
public:
static threadpool& getInstance() {
static threadpool instance;
return instance;
}
static threadpool *getNewForUnitTests(unsigned max_threads = 0) {
return new threadpool(max_threads);
}
// The waiter lets the caller know when all of its
// tasks are completed.
class waiter {
boost::mutex mt;
boost::condition_variable cv;
int num;
public:
void inc();
void dec();
void wait(threadpool *tpool); //! Wait for a set of tasks to finish.
waiter() : num(0){}
~waiter();
};
// Submit a task to the pool. The waiter pointer may be
// NULL if the caller doesn't care to wait for the
// task to finish.
void submit(waiter *waiter, std::function<void()> f, bool leaf = false);
// destroy and recreate threads
void recycle();
unsigned int get_max_concurrency() const;
~threadpool();
private:
threadpool(unsigned int max_threads = 0);
void destroy();
void create(unsigned int max_threads);
typedef struct entry {
waiter *wo;
std::function<void()> f;
bool leaf;
} entry;
std::deque<entry> queue;
boost::condition_variable has_work;
boost::mutex mutex;
std::vector<boost::thread> threads;
unsigned int active;
unsigned int max;
bool running;
void run(bool flush = false);
};
}