source: xplcommon/src/xplcommon/win32/Event.h@ 21:eb59943050c9

// Copyright (c) 2012 by István Váradi

// This file is part of libxplcommon, a common utility library for
// development related to X-Plane

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.

#ifndef XPLCOMMON_WIN32_EVENT_H
#define XPLCOMMON_WIN32_EVENT_H
//------------------------------------------------------------------------------

#include "EventFailable.h"

#include <windows.h>

//------------------------------------------------------------------------------

namespace xplcommon { namespace win32 {

//------------------------------------------------------------------------------

class Waiter;

//------------------------------------------------------------------------------

/**
 * Wrapper for an event.
 */
class Event
{
private:
    /**
     * The object receiving the failure codes.
     */
    EventFailable& eventFailable;

    /**
     * The handle of the event.
     */
    HANDLE handle;

    /**
     * The object waiting for the event.
     */
    Waiter* waiter;

public:
    /**
     * Construct the event.
     */
    Event(EventFailable& eventFailable);

    /**
     * Destroy the event. It will be removed from the waiter if it is
     * in one.
     */
    ~Event();

    /**
     * Get the handle of the event.
     */
    HANDLE getHandle() const;

    /**
     * Get the waiter.
     */
    Waiter* getWaiter() const;

    /**
     * Register the event with the given waiter. If it is already
     * registered with a waiter, it will be removed from that.
     */
    void addTo(Waiter& w);

    /**
     * Remove the object from the waiter it is registered with.
     */
    void removeFromWaiter();

    /**
     * Determine if the event is being waited for, i.e. it is
     * associated with a waiter.
     */
    bool isWaited() const;

    /**
     * Set the event.
     */
    void fire();

    /**
     * Determine if the event is fired or not.
     */
    bool isFired() const;

    /**
     * Clear the event.
     *
     * @return if clearing succeeded.
     */
    bool clear();

protected:
    /**
     * Set the error code on the failable object.
     */
    void setErrorCode(errorCode_t errorCode);
};

//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------

inline Event::Event(EventFailable& eventFailable) :
    eventFailable(eventFailable),
    handle(CreateEvent(0, true, false, 0)),
    waiter(0)
{
    if (handle==0) eventFailable.setErrorCode(GetLastError());
}

//------------------------------------------------------------------------------

inline Event::~Event()
{
    removeFromWaiter();
    CloseHandle(handle);
}

//------------------------------------------------------------------------------

inline HANDLE Event::getHandle() const
{
    return handle;
}

//------------------------------------------------------------------------------

inline Waiter* Event::getWaiter() const
{
    return waiter;
}

//------------------------------------------------------------------------------

inline bool Event::isWaited() const
{
    return waiter!=0;
}

//------------------------------------------------------------------------------

inline void Event::fire()
{
    if (!SetEvent(handle)) {
        eventFailable.setErrorCode(GetLastError());
    }
}

//------------------------------------------------------------------------------

inline bool Event::clear()
{
    if (!ResetEvent(handle)) {
        eventFailable.setErrorCode(GetLastError());
        return false;
    } else {
        return true;
    }
}

//------------------------------------------------------------------------------

inline void Event::setErrorCode(errorCode_t errorCode)
{
    eventFailable.setErrorCode(errorCode);
}

//------------------------------------------------------------------------------

} /* namespace xplcommon::win32 */ } /* namespace xplcommon */

//------------------------------------------------------------------------------
#endif // XPLCOMMON_WIN32_EVENT_H

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