request_with_waiters.h

Go to the documentation of this file.

/***************************************************************************
 * include/stxxl/bits/io/request_with_waiters.h
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002 Roman Dementiev <[email protected]>
 * Copyright (C) 2008 Andreas Beckmann <[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)
 **************************************************************************/

#ifndef STXXL_IO_REQUEST_WITH_WAITERS_HEADER
#define STXXL_IO_REQUEST_WITH_WAITERS_HEADER

#include <set>

#include <stxxl/bits/common/mutex.h>
#include <stxxl/bits/common/onoff_switch.h>
#include <stxxl/bits/io/request.h>
#include <stxxl/bits/namespace.h>

STXXL_BEGIN_NAMESPACE

//! \addtogroup reqlayer
//! \{

//! Request that is aware of threads waiting for it to complete.
class request_with_waiters : public request
{
 mutex m_waiters_mutex;
 std::set<onoff_switch*> m_waiters;

protected:
 bool add_waiter(onoff_switch* sw);
 void delete_waiter(onoff_switch* sw);
 void notify_waiters();

 //! returns number of waiters
 size_t num_waiters();

public:
 request_with_waiters(
 const completion_handler& on_cmpl,
 file* f,
 void* buf,
 offset_type off,
 size_type b,
 request_type t)
 : request(on_cmpl, f, buf, off, b, t)
 { }
};

//! \}

STXXL_END_NAMESPACE

#endif // !STXXL_IO_REQUEST_WITH_WAITERS_HEADER
// vim: et:ts=4:sw=4