thread_pool-inl.h

Go to the documentation of this file.

// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
#pragma once
 
#ifndef SPDLOG_HEADER_ONLY
#include <spdlog/details/thread_pool.h>
#endif
 
#include <spdlog/common.h>
#include <cassert>
 
namespace spdlog
{
    namespace details
    {
 
        SPDLOG_INLINE thread_pool::thread_pool(
            size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start, std::function<void()> on_thread_stop)
            : q_(q_max_items)
        {
            if (threads_n == 0 || threads_n > 1000)
            {
                throw_spdlog_ex("spdlog::thread_pool(): invalid threads_n param (valid "
                                "range is 1-1000)");
            }
            for (size_t i = 0; i < threads_n; i++)
            {
                threads_.emplace_back([this, on_thread_start, on_thread_stop] {
                    on_thread_start();
                    this->thread_pool::worker_loop_();
                    on_thread_stop();
                });
            }
        }
 
        SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start)
            : thread_pool(q_max_items, threads_n, on_thread_start, [] {})
        {
        }
 
        SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n)
            : thread_pool(
                  q_max_items, threads_n, [] {}, [] {})
        {
        }
 
        // message all threads to terminate gracefully join them
        SPDLOG_INLINE thread_pool::~thread_pool()
        {
            SPDLOG_TRY
            {
                for (size_t i = 0; i < threads_.size(); i++)
                {
                    post_async_msg_(async_msg(async_msg_type::terminate), async_overflow_policy::block);
                }
 
                for (auto& t : threads_)
                {
                    t.join();
                }
            }
            SPDLOG_CATCH_STD
        }
 
        void SPDLOG_INLINE thread_pool::post_log(async_logger_ptr&& worker_ptr, const details::log_msg& msg, async_overflow_policy overflow_policy)
        {
            async_msg async_m(std::move(worker_ptr), async_msg_type::log, msg);
            post_async_msg_(std::move(async_m), overflow_policy);
        }
 
        void SPDLOG_INLINE thread_pool::post_flush(async_logger_ptr&& worker_ptr, async_overflow_policy overflow_policy)
        {
            post_async_msg_(async_msg(std::move(worker_ptr), async_msg_type::flush), overflow_policy);
        }
 
        size_t SPDLOG_INLINE thread_pool::overrun_counter()
        {
            return q_.overrun_counter();
        }
 
        void SPDLOG_INLINE thread_pool::reset_overrun_counter()
        {
            q_.reset_overrun_counter();
        }
 
        size_t SPDLOG_INLINE thread_pool::queue_size()
        {
            return q_.size();
        }
 
        void SPDLOG_INLINE thread_pool::post_async_msg_(async_msg&& new_msg, async_overflow_policy overflow_policy)
        {
            if (overflow_policy == async_overflow_policy::block)
            {
                q_.enqueue(std::move(new_msg));
            }
            else
            {
                q_.enqueue_nowait(std::move(new_msg));
            }
        }
 
        void SPDLOG_INLINE thread_pool::worker_loop_()
        {
            while (process_next_msg_())
            {
            }
        }
 
        // process next message in the queue
        // return true if this thread should still be active (while no terminate msg
        // was received)
        bool SPDLOG_INLINE thread_pool::process_next_msg_()
        {
            async_msg incoming_async_msg;
            q_.dequeue(incoming_async_msg);
 
            switch (incoming_async_msg.msg_type)
            {
            case async_msg_type::log: {
                incoming_async_msg.worker_ptr->backend_sink_it_(incoming_async_msg);
                return true;
            }
            case async_msg_type::flush: {
                incoming_async_msg.worker_ptr->backend_flush_();
                return true;
            }
 
            case async_msg_type::terminate: {
                return false;
            }
 
            default: {
                assert(false);
            }
            }
 
            return true;
        }
 
    } // namespace details
} // namespace spdlog