base/pollevent.hh

   1 /*
   2  * Copyright (c) 2003 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef __POLLEVENT_H__
  30 #define __POLLEVENT_H__
  31
  32 #include <vector>
  33 #include <poll.h>
  34 #include "sim/universe.hh"
  35
  36 class Checkpoint;
  37
  38 class PollEvent
  39 {
  40   private:
  41     friend class PollQueue;
  42
  43   protected:
  44     pollfd pfd;
  45     PollQueue *queue;
  46     bool enabled;
  47
  48   public:
  49     PollEvent(int fd, int event);
  50     virtual ~PollEvent();
  51
  52     void disable();
  53     void enable();
  54     virtual void process(int revent) = 0;
  55
  56     bool queued() { return queue != 0; }
  57
  58     virtual void serialize(std::ostream &os);
  59     virtual void unserialize(Checkpoint *cp, const std::string &section);
  60 };
  61
  62 class PollQueue
  63 {
  64   private:
  65     typedef std::vector<PollEvent *> eventvec_t;
  66     eventvec_t events;
  67
  68     pollfd *poll_fds;
  69     int max_size;
  70     int num_fds;
  71
  72   public:
  73     PollQueue();
  74     ~PollQueue();
  75
  76     void copy();
  77     void remove(PollEvent *event);
  78     void schedule(PollEvent *event);
  79     void service();
  80
  81   protected:
  82     static bool handler;
  83     static struct sigaction oldio;
  84     static struct sigaction oldalrm;
  85
  86   public:
  87     static void setupAsyncIO(int fd, bool set);
  88     static void handleIO(int);
  89     static void handleALRM(int);
  90     static void removeHandler();
  91     static void setupHandler();
  92 };
  93
  94 extern PollQueue pollQueue;
  95
  96 #endif // __POLLEVENT_H__