///////////////////////////////////////////////////////////////////////////////

// Name:        wx/unix/private/wakeuppipe.h

// Purpose:     Helper class allowing to wake up the main thread.

// Author:      Vadim Zeitlin

// Created:     2013-06-09 (extracted from src/unix/evtloopunix.cpp)

// Copyright:   (c) 2013 Vadim Zeitlin <vadim@wxwidgets.org>

// Licence:     wxWindows licence

///////////////////////////////////////////////////////////////////////////////

#ifndef _WX_UNIX_PRIVATE_WAKEUPPIPE_H_

#define _WX_UNIX_PRIVATE_WAKEUPPIPE_H_

#include "wx/unix/pipe.h"

#include "wx/evtloopsrc.h"

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

// wxWakeUpPipe: allows to wake up the event loop by writing to it

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

// This class is MT-safe and its WakeUp() can be called from any thread and

// even from a signal handler.

class wxWakeUpPipe : public wxEventLoopSourceHandler

{

public:

    // Create and initialize the pipe.

    //

    // It's the callers responsibility to add the read end of this pipe,

    // returned by GetReadFd(), to the code blocking on input.

    wxWakeUpPipe();

    // Wake up the blocking operation involving this pipe.

    //

    // It simply writes to the write end of the pipe, which is non-blocking,

    // and doesn't do anything else, so it can be called from any thread and

    // also from a signal handler (it also preserves errno for this reason).

    void WakeUp();

    // Return the read end of the pipe.

    int GetReadFd() { return m_pipe[wxPipe::Read]; }

    // Implement wxEventLoopSourceHandler pure virtual methods

    virtual void OnReadWaiting() override;

    virtual void OnWriteWaiting() override { }

    virtual void OnExceptionWaiting() override { }

private:

    wxPipe m_pipe;

};

#endif // _WX_UNIX_PRIVATE_WAKEUPPIPE_H_