request_with_state.cpp

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/***************************************************************************
 *  lib/io/request_with_state.cpp
 *
 *  Part of the STXXL. See http://stxxl.sourceforge.net
 *
 *  Copyright (C) 2002, 2005, 2008 Roman Dementiev <[email protected]>
 *  Copyright (C) 2008 Andreas Beckmann <[email protected]>
 *  Copyright (C) 2009 Johannes Singler <[email protected]>
 *
 *  Distributed under the Boost Software License, Version 1.0.
 *  (See accompanying file LICENSE_1_0.txt or copy at
 *  http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/

#include <stxxl/bits/common/state.h>
#include <stxxl/bits/io/disk_queues.h>
#include <stxxl/bits/io/file.h>
#include <stxxl/bits/io/iostats.h>
#include <stxxl/bits/io/request.h>
#include <stxxl/bits/io/request_with_state.h>
#include <stxxl/bits/singleton.h>
#include <stxxl/bits/verbose.h>

#include <cassert>

STXXL_BEGIN_NAMESPACE

request_with_state::~request_with_state()
{
    STXXL_VERBOSE3_THIS("request_with_state::~(), ref_cnt: " << get_reference_count());

    assert(m_state() == DONE || m_state() == READY2DIE);

    // if(m_state() != DONE && m_state()!= READY2DIE )
    // STXXL_ERRMSG("WARNING: serious stxxl inconsistency: Request is being deleted while I/O not finished. "<<
    //              "Please submit a bug report.");

    // m_state.wait_for (READY2DIE); // does not make sense ?
}

void request_with_state::wait(bool measure_time)
{
    STXXL_VERBOSE3_THIS("request_with_state::wait()");

    stats::scoped_wait_timer wait_timer(m_type == READ ? stats::WAIT_OP_READ : stats::WAIT_OP_WRITE, measure_time);

    m_state.wait_for(READY2DIE);

    check_errors();
}

bool request_with_state::cancel()
{
    STXXL_VERBOSE3_THIS("request_with_state::cancel() " << m_file << " " << m_buffer << " " << m_offset);

    if (m_file)
    {
        request_ptr rp(this);
        if (disk_queues::get_instance()->cancel_request(rp, m_file->get_queue_id()))
        {
            m_state.set_to(DONE);
            notify_waiters();
            m_file->delete_request_ref();
            m_file = 0;
            m_state.set_to(READY2DIE);
            return true;
        }
    }
    return false;
}

bool request_with_state::poll()
{
    const request_state s = m_state();

    check_errors();

    return s == DONE || s == READY2DIE;
}

void request_with_state::completed(bool canceled)
{
    STXXL_VERBOSE3_THIS("request_with_state::completed()");
    m_state.set_to(DONE);
    if (!canceled)
        m_on_complete(this);
    notify_waiters();
    m_file->delete_request_ref();
    m_file = 0;
    m_state.set_to(READY2DIE);
}

STXXL_END_NAMESPACE

// vim: et:ts=4:sw=4