ccocontext.h

研读AxCrypt对加解密的处理方法

#pragma once
#ifndef AXPIPE_CCOCONTEXT_H
#define AXPIPE_CCOCONTEXT_H
/*! \file
    \brief Co-routine context class wrapper

    @(#) $Id: CCoContext.h,v 1.2 2004/01/01 20:05:53 svante Exp $

    AxPipe - Binary Stream Framework

    Copyright (C) 2003 Svante Seleborg/Axon Data, All rights reserved.

    This program is free software; you can redistribute it and/or modify it under the terms
    of the GNU General Public License as published by the Free Software Foundation;
    either version 2 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
    without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along with this program;
    if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
    Boston, MA 02111-1307 USA

    The author may be reached at mailto:[e-mail] and http://axpipe.sourceforge.net

    Why is this framework released as GPL and not LGPL?
    See http://www.gnu.org/philosophy/why-not-lgpl.html

----
\verbatim
    CCoContext.h                    Co-routine context class wrapper

    E-mail                          YYYY-MM-DD              Reason
    [e-mail]              2003-12-08              Initial
\endverbatim
*/
#include "AxPipe.h"

#include "AxAssert.h"
#define AXLIB_ASSERT_FILE "CCoContext.h"

namespace AxPipe {
/// \brief Encapsulate a co-routine context.
///
/// A co-routine is a context that executes along with other co-routines
/// in the same process and thread, but with it's own stack, registers and
/// program counter - sort of a very light weight thread, but with no
/// independent scheduling, and by definition no concurrent or parallell
/// execution.
///
/// In Windows Win32, this concept is called a 'fiber'.
/// A CCoContext can be initalized to represent the already executing current
/// context, or to create a new execution context. In most cases you first
/// want to make a context represent the current context, then create a new
/// context, that can then switch back to the original and then back again as
/// needed.
///
/// The constructors may be called in any context. No creation or switching
/// of contexts are done there.
///
/// Each CCoContext object thus represents one co-routine context in a thread.
class CCoContext {
    DWORD m_dwThreadId;                     ///< The thread we started the fiber in.
    LPVOID m_pFiber;                        ///< This objects co-routine state

    void (*m_pfStart)(void *);              ///< Pointer to a StartProc
    void *m_pvParam;                        ///< The parameter sent to the StartProc
    CError *m_pErr;                         ///< Point to an object where we can report an error.

public:
    /// \brief Create a new co-routine context.
    CCoContext(CError *pErr = NULL, void (*pfStart)(void *) = NULL, void *pvParam = NULL);
    /// \brief Initalize the error object pointer, the StartProc and the param
    void Init(CError *pErr, void (*pfStart)(void *), void *pvParam);
    
    ~CCoContext();                          ///< Stop this context.
    static VOID CALLBACK Start(PVOID lpParam); ///< Helper for the CreateFiber call, needs a static callback, this is it.
    bool Go();                              ///< Switch to this objects coroutine context.
    void Stop();                            ///< Stop and delete a co-routine context state.
}; // class CCoContext

}; // namespace AxPipe
#endif AXPIPE_CTHREAD_H