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
  39 void
  40 CommIO::Initialise()
  41 {
  42     /* Initialize done pipe signal */
  43     int DonePipe[2];
  44     if (pipe(DonePipe)) {}
  45     DoneFD = DonePipe[1];
  46     DoneReadFD = DonePipe[0];
  47     fd_open(DoneReadFD, FD_PIPE, "async-io completetion event: main");
  48     fd_open(DoneFD, FD_PIPE, "async-io completetion event: threads");
  49     commSetNonBlocking(DoneReadFD);
  50     commSetNonBlocking(DoneFD);
  51     Comm::SetSelect(DoneReadFD, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  52     Initialised = true;
  53 }
  54
  55 void
  56 CommIO::NotifyIOClose()
  57 {
  58     /* Close done pipe signal */
  59     FlushPipe();
  60     close(DoneFD);
  61     close(DoneReadFD);
  62     fd_close(DoneFD);
  63     fd_close(DoneReadFD);
  64     Initialised = false;
  65 }
  66
  67 bool CommIO::Initialised = false;
  68 bool CommIO::DoneSignalled = false;
  69 int CommIO::DoneFD = -1;
  70 int CommIO::DoneReadFD = -1;
  71
  72 void
  73 CommIO::FlushPipe()
  74 {
  75     char buf[256];
  76     FD_READ_METHOD(DoneReadFD, buf, sizeof(buf));
  77 }
  78
  79 void
  80 CommIO::NULLFDHandler(int fd, void *data)
  81 {
  82     FlushPipe();
  83     Comm::SetSelect(fd, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  84 }
  85
  86 void
  87 CommIO::ResetNotifications()
  88 {
  89     if (DoneSignalled) {
  90         FlushPipe();
  91         DoneSignalled = false;
  92     }
  93 }