terminator.h

来自「一个语言识别引擎」· C头文件 代码 · 共 94 行

// -*- mode:C++; tab-width:4; c-basic-offset:4; indent-tabs-mode:nil -*-

/*
 * Copyright (C) 2006 Giorgio Metta
 * CopyPolicy: Released under the terms of the GNU GPL v2.0.
 *
 */

#ifndef __TERMINATORH__
#define __TERMINATORH__

// $Id: Terminator.h,v 1.10 2006/10/24 19:14:48 eshuy Exp $


#include <yarp/os/Thread.h>

namespace yarp {
    namespace os {
        class Terminator;
        class Terminee;
    }
}

/**
 * \file Terminator.h classes to handle graceful process termination.
 */

/**
 * Send a message to a process that has a corresponding
 * socket port created using the Terminee class to ask to start
 * a graceful quit procedure. The receiving process must
 * collaborate and take appropriate action after receiving the
 * message. The Terminator/Terminee class pair starts a tcp socket on the 
 * server side listening for incoming connections and the magic word "quit" 
 * (all lowercase). The ip-port pair is registered with a symbolic name
 * on the Yarp name server and can be queried by the client to send the 
 * termination message.
 */
class yarp::os::Terminator {
public:
    /** 
     * Send a quit message to a specific socket port.
     * @param name is the name of the socket port (as registered in 
     * the name server).
     * @return true/false on success/failure.
     */
    static bool terminateByName(const char *name);
};

/**
 * A class that can be polled to see whether the process has been 
 * asked to quit gracefully.
 */ 
class yarp::os::Terminee : public yarp::os::Thread {
protected:
    void *implementation;
    volatile bool quit;
    volatile bool ok;

public:
    /**
     * Constructor. 
     * @param name is the nickname to register on the name server.
     */
    Terminee(const char *name);

    /**
     * Destructor.
     */
    virtual ~Terminee();


    virtual void run();


    // LATER: mustQuitBlocking() to wait on a semaphore.

    /**
     * Call this method to see whether a quit message has
     * been received.
     * @return true is a quit has been received, false otherwise.
     */
    bool mustQuit() const { return quit; }

    /**
     * Check whether the message mechanism is ok.
     * @return true if ok, false otherwise.
     */
    bool isOk() const { return ok; }
};


#endif