ipc/unixfd/UnixFdWatcher.cpp

   1 /* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include <fcntl.h>
   8 #include "UnixFdWatcher.h"
   9
  10 #ifdef CHROMIUM_LOG
  11 #undef CHROMIUM_LOG
  12 #endif
  13
  14 #if defined(MOZ_WIDGET_GONK)
  15 #include <android/log.h>
  16 #define CHROMIUM_LOG(args...)  __android_log_print(ANDROID_LOG_INFO, "I/O", args);
  17 #else
  18 #include <stdio.h>
  19 #define IODEBUG true
  20 #define CHROMIUM_LOG(args...) if (IODEBUG) printf(args);
  21 #endif
  22
  23 namespace mozilla {
  24 namespace ipc {
  25
  26 UnixFdWatcher::~UnixFdWatcher()
  27 {
  28   NS_WARN_IF(IsOpen()); /* mFd should have been closed already */
  29 }
  30
  31 void
  32 UnixFdWatcher::Close()
  33 {
  34   MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
  35
  36   if (NS_WARN_IF(!IsOpen())) {
  37     /* mFd should have been open */
  38     return;
  39   }
  40   OnClose();
  41   RemoveWatchers(READ_WATCHER|WRITE_WATCHER);
  42   mFd.dispose();
  43 }
  44
  45 void
  46 UnixFdWatcher::AddWatchers(unsigned long aWatchers, bool aPersistent)
  47 {
  48   MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
  49   MOZ_ASSERT(IsOpen());
  50
  51   // Before we add a watcher, we need to remove it! Removing is always
  52   // safe, but adding the same watcher twice can lead to endless loops
  53   // inside libevent.
  54   RemoveWatchers(aWatchers);
  55
  56   if (aWatchers & READ_WATCHER) {
  57     MessageLoopForIO::current()->WatchFileDescriptor(
  58       mFd,
  59       aPersistent,
  60       MessageLoopForIO::WATCH_READ,
  61       &mReadWatcher,
  62       this);
  63   }
  64   if (aWatchers & WRITE_WATCHER) {
  65     MessageLoopForIO::current()->WatchFileDescriptor(
  66       mFd,
  67       aPersistent,
  68       MessageLoopForIO::WATCH_WRITE,
  69       &mWriteWatcher,
  70       this);
  71   }
  72 }
  73
  74 void
  75 UnixFdWatcher::RemoveWatchers(unsigned long aWatchers)
  76 {
  77   MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
  78   MOZ_ASSERT(IsOpen());
  79
  80   if (aWatchers & READ_WATCHER) {
  81     mReadWatcher.StopWatchingFileDescriptor();
  82   }
  83   if (aWatchers & WRITE_WATCHER) {
  84     mWriteWatcher.StopWatchingFileDescriptor();
  85   }
  86 }
  87
  88 void
  89 UnixFdWatcher::OnError(const char* aFunction, int aErrno)
  90 {
  91   MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
  92
  93   CHROMIUM_LOG("%s failed with error %d (%s)",
  94                aFunction, aErrno, strerror(aErrno));
  95 }
  96
  97 UnixFdWatcher::UnixFdWatcher(MessageLoop* aIOLoop)
  98 : mIOLoop(aIOLoop)
  99 {
 100   MOZ_ASSERT(mIOLoop);
 101 }
 102
 103 UnixFdWatcher::UnixFdWatcher(MessageLoop* aIOLoop, int aFd)
 104 : mIOLoop(aIOLoop)
 105 , mFd(aFd)
 106 {
 107   MOZ_ASSERT(mIOLoop);
 108 }
 109
 110 void
 111 UnixFdWatcher::SetFd(int aFd)
 112 {
 113   MOZ_ASSERT(MessageLoopForIO::current() == mIOLoop);
 114   MOZ_ASSERT(!IsOpen());
 115   MOZ_ASSERT(FdIsNonBlocking(aFd));
 116
 117   mFd = aFd;
 118 }
 119
 120 bool
 121 UnixFdWatcher::FdIsNonBlocking(int aFd)
 122 {
 123   int flags = TEMP_FAILURE_RETRY(fcntl(aFd, F_GETFL));
 124   return (flags > 0) && (flags & O_NONBLOCK);
 125 }
 126
 127 }
 128 }