src/DiskIO/DiskThreads/CommIO.cc

   1 /*
   2  * DEBUG: section 05    Disk I/O pipe manager
   3  * AUTHOR: Harvest Derived
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  *
  32  * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
  33  */
  34
  35 #include "squid.h"
  36 #include "comm/Loops.h"
  37 #include "DiskIO/DiskThreads/CommIO.h"
  38 #include "globals.h"
  39 #include "protos.h"
  40
  41 void
  42 CommIO::Initialise()
  43 {
  44     /* Initialize done pipe signal */
  45     int DonePipe[2];
  46     if (pipe(DonePipe)) {}
  47     DoneFD = DonePipe[1];
  48     DoneReadFD = DonePipe[0];
  49     fd_open(DoneReadFD, FD_PIPE, "async-io completetion event: main");
  50     fd_open(DoneFD, FD_PIPE, "async-io completetion event: threads");
  51     commSetNonBlocking(DoneReadFD);
  52     commSetNonBlocking(DoneFD);
  53     Comm::SetSelect(DoneReadFD, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  54     Initialised = true;
  55 }
  56
  57 void
  58 CommIO::NotifyIOClose()
  59 {
  60     /* Close done pipe signal */
  61     FlushPipe();
  62     close(DoneFD);
  63     close(DoneReadFD);
  64     fd_close(DoneFD);
  65     fd_close(DoneReadFD);
  66     Initialised = false;
  67 }
  68
  69 bool CommIO::Initialised = false;
  70 bool CommIO::DoneSignalled = false;
  71 int CommIO::DoneFD = -1;
  72 int CommIO::DoneReadFD = -1;
  73
  74 void
  75 CommIO::FlushPipe()
  76 {
  77     char buf[256];
  78     FD_READ_METHOD(DoneReadFD, buf, sizeof(buf));
  79 }
  80
  81 void
  82 CommIO::NULLFDHandler(int fd, void *data)
  83 {
  84     FlushPipe();
  85     Comm::SetSelect(fd, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  86 }
  87
  88 void
  89 CommIO::ResetNotifications()
  90 {
  91     if (DoneSignalled) {
  92         FlushPipe();
  93         DoneSignalled = false;
  94     }
  95 }