thread_pool_observer.cpp

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/* This file is part of Metaproxy.
   Copyright (C) Index Data
 
Metaproxy is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
 
Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
 
#include "config.hpp"
 
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
 
#ifdef WIN32
#include <windows.h>
#include <winsock.h>
#endif
#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition.hpp>
#include <boost/noncopyable.hpp>
 
#include <ctype.h>
#include <stdio.h>
 
#include <deque>
#include <sstream>
 
#include <yazpp/socket-observer.h>
#include <yaz/log.h>
 
#include "thread_pool_observer.hpp"
#include "pipe.hpp"
 
namespace metaproxy_1 {
    class ThreadPoolSocketObserver::Worker {
    public:
        Worker(ThreadPoolSocketObserver *s) : m_s(s) {};
        ThreadPoolSocketObserver *m_s;
        void operator() (void) {
            m_s->run(0);
        }
    };
 
    class ThreadPoolSocketObserver::Rep : public boost::noncopyable {
        friend class ThreadPoolSocketObserver;
    public:
        Rep(yazpp_1::ISocketObservable *obs);
        ~Rep();
    private:
        yazpp_1::ISocketObservable *m_socketObservable;
        Pipe m_pipe;
        boost::thread_group m_thrds;
        boost::mutex m_mutex_input_data;
        boost::condition m_cond_input_data;
        boost::condition m_cond_input_full;
        boost::mutex m_mutex_output_data;
        std::deque<IThreadPoolMsg *> m_input;
        std::deque<IThreadPoolMsg *> m_output;
        bool m_stop_flag;
#if BOOST_VERSION >= 105000
        boost::thread::attributes attrs;
#endif
        unsigned m_no_threads;
        unsigned m_min_threads;
        unsigned m_max_threads;
        unsigned m_waiting_threads;
    };
    const unsigned int queue_size_per_thread = 64;
}
 
 
 
using namespace yazpp_1;
using namespace metaproxy_1;
 
ThreadPoolSocketObserver::Rep::Rep(yazpp_1::ISocketObservable *obs)
    : m_socketObservable(obs), m_pipe(9123)
{
}
 
ThreadPoolSocketObserver::Rep::~Rep()
{
}
 
IThreadPoolMsg::~IThreadPoolMsg()
{
 
}
 
ThreadPoolSocketObserver::ThreadPoolSocketObserver(
    yazpp_1::ISocketObservable *obs,
    unsigned min_threads, unsigned max_threads,
    unsigned stack_size)
    : m_p(new Rep(obs))
{
    obs->addObserver(m_p->m_pipe.read_fd(), this);
    obs->maskObserver(this, SOCKET_OBSERVE_READ);
 
    m_p->m_stop_flag = false;
    m_p->m_no_threads = 0;
    m_p->m_min_threads = min_threads;
    m_p->m_max_threads = max_threads;
    m_p->m_waiting_threads = 0;
    unsigned i;
#if BOOST_VERSION >= 105000
    if (stack_size > 0)
        m_p->attrs.set_stack_size(stack_size);
#else
    if (stack_size)
        yaz_log(YLOG_WARN, "stack_size has no effect (Requires Boost 1.50)");
#endif
    for (i = 0; i < min_threads; i++)
        add_worker();
}
 
ThreadPoolSocketObserver::~ThreadPoolSocketObserver()
{
    {
        boost::mutex::scoped_lock input_lock(m_p->m_mutex_input_data);
        m_p->m_stop_flag = true;
        m_p->m_cond_input_data.notify_all();
    }
    m_p->m_thrds.join_all();
    m_p->m_socketObservable->deleteObserver(this);
}
 
void ThreadPoolSocketObserver::add_worker(void)
{
    Worker w(this);
#if BOOST_VERSION >= 105000
    boost::thread *x = new boost::thread(m_p->attrs, w);
#else
    boost::thread *x = new boost::thread(w);
#endif
    m_p->m_no_threads++;
    m_p->m_thrds.add_thread(x);
}
 
void ThreadPoolSocketObserver::socketNotify(int event)
{
    if (event & SOCKET_OBSERVE_READ)
    {
        char buf[2];
#ifdef WIN32
        recv(m_p->m_pipe.read_fd(), buf, 1, 0);
#else
        ssize_t r = read(m_p->m_pipe.read_fd(), buf, 1);
        if (r != 1)
        {
            if (r == (ssize_t) (-1))
                yaz_log(YLOG_WARN|YLOG_ERRNO,
                        "ThreadPoolSocketObserver::socketNotify. read fail");
            else
                yaz_log(YLOG_WARN,
                        "ThreadPoolSocketObserver::socketNotify. read returned 0");
        }
#endif
        while (1)
        {
            IThreadPoolMsg *out;
            size_t output_size = 0;
            {
                boost::mutex::scoped_lock output_lock(m_p->m_mutex_output_data);
                if (m_p->m_output.empty()) {
                    break;
                }
                out = m_p->m_output.front();
                m_p->m_output.pop_front();
                output_size = m_p->m_output.size();
            }
            if (out)
            {
                size_t input_size = 0;
                std::ostringstream os;
                {
                    boost::mutex::scoped_lock input_lock(m_p->m_mutex_input_data);
                    input_size = m_p->m_input.size();
                }
                os << "tbusy/total "
                    << m_p->m_no_threads - m_p->m_waiting_threads
                    << "/" << m_p->m_no_threads
                    << " queue in/out " << input_size << "/" <<  output_size;
                out->result(os.str().c_str());
            }
        }
    }
}
 
void ThreadPoolSocketObserver::get_thread_info(int &tbusy, int &total)
{
    tbusy = m_p->m_no_threads - m_p->m_waiting_threads;
    total = m_p->m_no_threads;
}
 
void ThreadPoolSocketObserver::run(void *p)
{
    while(1)
    {
        IThreadPoolMsg *in = 0;
        {
            boost::mutex::scoped_lock input_lock(m_p->m_mutex_input_data);
            m_p->m_waiting_threads++;
            while (!m_p->m_stop_flag && m_p->m_input.size() == 0)
                m_p->m_cond_input_data.wait(input_lock);
            m_p->m_waiting_threads--;
            if (m_p->m_stop_flag)
                break;
 
            in = m_p->m_input.front();
            m_p->m_input.pop_front();
            m_p->m_cond_input_full.notify_all();
        }
        IThreadPoolMsg *out = in->handle();
        {
            boost::mutex::scoped_lock output_lock(m_p->m_mutex_output_data);
            m_p->m_output.push_back(out);
#ifdef WIN32
            send(m_p->m_pipe.write_fd(), "", 1, 0);
#else
            ssize_t r = write(m_p->m_pipe.write_fd(), "", 1);
            if (r != 1)
            {
                if (r == (ssize_t) (-1))
                    yaz_log(YLOG_WARN|YLOG_ERRNO,
                            "ThreadPoolSocketObserver::run. write fail");
                else
                    yaz_log(YLOG_WARN,
                            "ThreadPoolSocketObserver::run. write returned 0");
            }
#endif
        }
    }
}
 
void ThreadPoolSocketObserver::cleanup(IThreadPoolMsg *m, void *info)
{
    boost::mutex::scoped_lock input_lock(m_p->m_mutex_input_data);
 
    std::deque<IThreadPoolMsg *>::iterator it = m_p->m_input.begin();
    while (it != m_p->m_input.end())
    {
        if ((*it)->cleanup(info))
        {
            delete *it;
            it = m_p->m_input.erase(it);
        }
        else
            it++;
    }
}
 
void ThreadPoolSocketObserver::put(IThreadPoolMsg *m)
{
    boost::mutex::scoped_lock input_lock(m_p->m_mutex_input_data);
    if (m_p->m_waiting_threads == 0 &&
        m_p->m_no_threads < m_p->m_max_threads)
    {
        add_worker();
    }
    while (m_p->m_input.size() >= m_p->m_no_threads * queue_size_per_thread)
        m_p->m_cond_input_full.wait(input_lock);
    m_p->m_input.push_back(m);
    m_p->m_cond_input_data.notify_one();
}
 
/*
 * Local variables:
 * c-basic-offset: 4
 * c-file-style: "Stroustrup"
 * indent-tabs-mode: nil
 * End:
 * vim: shiftwidth=4 tabstop=8 expandtab
 */