src/utils/shared_io_service.cpp

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 "shared_io_service.h"

#include <boost/asio/impl/io_context.hpp>
#include <boost/asio/impl/io_context.ipp>
#include <stdint.h>

#include "utils/flags.h"
#include "utils/fmt_logging.h"

static const uint32_t kMinTimerServiceWorkerCount = 3;
DSN_DEFINE_uint32(core,
                  timer_service_worker_count,
                  kMinTimerServiceWorkerCount,
                  "the number of threads for timer service");
DSN_DEFINE_validator(timer_service_worker_count, [](uint32_t worker_count) -> bool {
    if (worker_count < kMinTimerServiceWorkerCount) {
        LOG_ERROR(
            "timer_service_worker_count should be at least 3, where one thread is used to "
            "collect all metrics from registery for monitoring systems, and another two threads "
            "are used to compute percentiles.");
        return false;
    }
    return true;
});

namespace dsn {
namespace tools {

shared_io_service::shared_io_service()
{
    _workers.reserve(FLAGS_timer_service_worker_count);
    for (uint32_t i = 0; i < FLAGS_timer_service_worker_count; ++i) {
        _workers.emplace_back([this]() {
            boost::asio::io_service::work work(ios);
            ios.run();
        });
    }
}

shared_io_service::~shared_io_service()
{
    ios.stop();
    for (auto &worker : _workers) {
        worker.join();
    }
}

} // namespace tools
} // namespace dsn