request_with_state.cpp

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/***************************************************************************
 *  foxxll/io/request_with_state.cpp
 *
 *  Part of FOXXLL. See http://foxxll.org
 *
 *  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 <cassert>

#include <foxxll/common/shared_state.hpp>
#include <foxxll/io/disk_queues.hpp>
#include <foxxll/io/file.hpp>
#include <foxxll/io/iostats.hpp>
#include <foxxll/io/request.hpp>
#include <foxxll/io/request_with_state.hpp>
#include <foxxll/singleton.hpp>

namespace foxxll {

request_with_state::~request_with_state()
{
    TLX_LOG << "request_with_state[" << static_cast<void*>(this) << "]::~(), ref_cnt: " << reference_count();

    assert(state_() == DONE || state_() == READY2DIE);
}

void request_with_state::wait(bool measure_time)
{
    TLX_LOG << "request_with_state[" << static_cast<void*>(this) << "]::wait()";

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

    state_.wait_for(READY2DIE);

    check_errors();
}

bool request_with_state::cancel()
{
    TLX_LOG << "request_with_state[" << static_cast<void*>(this) << "]::cancel() "
            << file_ << " " << buffer_ << " " << offset_;

    if (!file_) return false;

    // TODO(tb): remove
    request_ptr rp(this);
    if (disk_queues::get_instance()->cancel_request(rp, file_->get_queue_id()))
    {
        state_.set_to(DONE);
        if (on_complete_)
            on_complete_(this, /* success */ false);
        notify_waiters();
        file_->delete_request_ref();
        file_ = nullptr;
        state_.set_to(READY2DIE);
        return true;
    }
    return false;
}

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

    check_errors();

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

void request_with_state::completed(bool canceled)
{
    TLX_LOG << "request_with_state[" << static_cast<void*>(this) << "]::completed()";
    // change state
    state_.set_to(DONE);
    // user callback
    if (on_complete_)
        on_complete_(this, !canceled);
    notify_waiters();
    // delete request reference in file
    release_file_reference();
    state_.set_to(READY2DIE);
}

} // namespace foxxll

/**************************************************************************/