/* -*- compile-command: "make -k -j3"; -*- */

/* 
 * Copyright 2010-2012 by Eric House (xwords@eehouse.org).  All rights
 * reserved.
 *
 * This program 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
 * of the License, or (at your option) any later version.
 *
 * This program 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "udpqueue.h"
#include "mlock.h"


static UdpQueue* s_instance = NULL;


void 
UdpThreadClosure::logStats()
{
    time_t now = time( NULL );
    if ( 1 < now - m_created ) {
        logf( XW_LOGERROR, "packet waited %d s for processing which then took %d s",
              m_dequed - m_created, now - m_dequed );
    }
}

UdpQueue::UdpQueue() 
    :m_cb(NULL)
{
    pthread_mutex_init ( &m_queueMutex, NULL );
    pthread_cond_init( &m_queueCondVar, NULL );

    pthread_t thread;
    int result = pthread_create( &thread, NULL, thread_main_static, this );
    assert( result == 0 );
    result = pthread_detach( thread );
    assert( result == 0 );
}

UdpQueue::~UdpQueue() 
{
    pthread_cond_destroy( &m_queueCondVar );
    pthread_mutex_destroy ( &m_queueMutex );
}

UdpQueue* 
UdpQueue::get()
{
    if ( s_instance == NULL ) {
        s_instance = new UdpQueue();
    }
    return s_instance;
}

void 
UdpQueue::handle( const AddrInfo::AddrUnion* saddr, unsigned char* buf, int len, 
                  QueueCallback cb )
{
    UdpThreadClosure* utc = new UdpThreadClosure( saddr, buf, len );
    MutexLock ml( &m_queueMutex );
    setCB( cb );
    m_queue.push_back( utc );
    pthread_cond_signal( &m_queueCondVar );
}

void* 
UdpQueue::thread_main()
{
    for ( ; ; ) {
        pthread_mutex_lock( &m_queueMutex );
        while ( m_queue.size() == 0 ) {
            pthread_cond_wait( &m_queueCondVar, &m_queueMutex );
        }
        UdpThreadClosure* utc = m_queue.front();
        m_queue.pop_front();
        pthread_mutex_unlock( &m_queueMutex );

        utc->noteDequeued();
        (*m_cb)( utc );
        utc->logStats();
        delete utc;
    }
    return NULL;
}

/* static */ void*
UdpQueue::thread_main_static( void* closure )
{
    blockSignals();

    UdpQueue* me = (UdpQueue*)closure;
    return me->thread_main();
}

void
UdpQueue::setCB( QueueCallback cb )
{
    assert( cb == m_cb || !m_cb );
    m_cb = cb;
}