src/DiskIO/DiskThreads/CommIO.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 05    Disk I/O pipe manager */
  10
  11 #include "squid.h"
  12 #include "comm/Loops.h"
  13 #include "DiskIO/DiskThreads/CommIO.h"
  14 #include "fd.h"
  15 #include "globals.h"
  16 #include "win32.h"
  17
  18 void
  19 CommIO::Initialize()
  20 {
  21     if (CommIO::Initialized)
  22         return;
  23
  24     /* Initialize done pipe signal */
  25     int DonePipe[2];
  26     if (pipe(DonePipe)) {}
  27     DoneFD = DonePipe[1];
  28     DoneReadFD = DonePipe[0];
  29     fd_open(DoneReadFD, FD_PIPE, "async-io completion event: main");
  30     fd_open(DoneFD, FD_PIPE, "async-io completion event: threads");
  31     commSetNonBlocking(DoneReadFD);
  32     commSetNonBlocking(DoneFD);
  33     Comm::SetSelect(DoneReadFD, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  34     Initialized = true;
  35 }
  36
  37 void
  38 CommIO::NotifyIOClose()
  39 {
  40     /* Close done pipe signal */
  41     FlushPipe();
  42     close(DoneFD);
  43     close(DoneReadFD);
  44     fd_close(DoneFD);
  45     fd_close(DoneReadFD);
  46     Initialized = false;
  47 }
  48
  49 bool CommIO::Initialized = false;
  50 bool CommIO::DoneSignalled = false;
  51 int CommIO::DoneFD = -1;
  52 int CommIO::DoneReadFD = -1;
  53
  54 void
  55 CommIO::FlushPipe()
  56 {
  57     char buf[256];
  58     FD_READ_METHOD(DoneReadFD, buf, sizeof(buf));
  59 }
  60
  61 void
  62 CommIO::NULLFDHandler(int fd, void *)
  63 {
  64     FlushPipe();
  65     Comm::SetSelect(fd, COMM_SELECT_READ, NULLFDHandler, NULL, 0);
  66 }
  67
  68 void
  69 CommIO::ResetNotifications()
  70 {
  71     if (DoneSignalled) {
  72         FlushPipe();
  73         DoneSignalled = false;
  74     }
  75 }
  76