gem5/base/pollevent.hh

/*
 * Copyright (c) 2002-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * 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;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * 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.
 */

#ifndef __POLLEVENT_H__
#define __POLLEVENT_H__

#include <vector>
#include <poll.h>
#include "sim/root.hh"

class Checkpoint;
class PollQueue;

class PollEvent
{
  private:
    friend class PollQueue;

  protected:
    pollfd pfd;
    PollQueue *queue;
    bool enabled;

  public:
    PollEvent(int fd, int event);
    virtual ~PollEvent();

    void disable();
    void enable();
    virtual void process(int revent) = 0;

    bool queued() { return queue != 0; }

    virtual void serialize(std::ostream &os);
    virtual void unserialize(Checkpoint *cp, const std::string &section);
};

class PollQueue
{
  private:
    typedef std::vector<PollEvent *> eventvec_t;
    eventvec_t events;

    pollfd *poll_fds;
    int max_size;
    int num_fds;

  public:
    PollQueue();
    ~PollQueue();

    void copy();
    void remove(PollEvent *event);
    void schedule(PollEvent *event);
    void service();

  protected:
    static bool handler;
    static struct sigaction oldio;
    static struct sigaction oldalrm;

  public:
    static void setupAsyncIO(int fd, bool set);
    static void handleIO(int);
    static void handleALRM(int);
    static void removeHandler();
    static void setupHandler();
};

extern PollQueue pollQueue;

#endif // __POLLEVENT_H__