content/browser/udev_linux.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/udev_linux.h"
   6
   7 #include <libudev.h>
   8
   9 #include "base/message_loop.h"
  10
  11 namespace content {
  12
  13 UdevLinux::UdevLinux(const std::vector<UdevMonitorFilter>& filters,
  14                      const UdevNotificationCallback& callback)
  15     : udev_(udev_new()),
  16       monitor_(NULL),
  17       monitor_fd_(-1),
  18       callback_(callback) {
  19   CHECK(udev_);
  20
  21   monitor_ = udev_monitor_new_from_netlink(udev_, "udev");
  22   CHECK(monitor_);
  23
  24   for (size_t i = 0; i < filters.size(); ++i) {
  25     int ret = udev_monitor_filter_add_match_subsystem_devtype(
  26         monitor_, filters[i].subsystem, filters[i].devtype);
  27     CHECK_EQ(0, ret);
  28   }
  29
  30   int ret = udev_monitor_enable_receiving(monitor_);
  31   CHECK_EQ(0, ret);
  32   monitor_fd_ = udev_monitor_get_fd(monitor_);
  33   CHECK_GE(monitor_fd_, 0);
  34
  35   bool success = MessageLoopForIO::current()->WatchFileDescriptor(monitor_fd_,
  36       true, MessageLoopForIO::WATCH_READ, &monitor_watcher_, this);
  37   CHECK(success);
  38 }
  39
  40 UdevLinux::~UdevLinux() {
  41   monitor_watcher_.StopWatchingFileDescriptor();
  42   udev_monitor_unref(monitor_);
  43   udev_unref(udev_);
  44 }
  45
  46 udev* UdevLinux::udev_handle() {
  47   return udev_;
  48 }
  49
  50 void UdevLinux::OnFileCanReadWithoutBlocking(int fd) {
  51   // Events occur when devices attached to the system are added, removed, or
  52   // change state. udev_monitor_receive_device() will return a device object
  53   // representing the device which changed and what type of change occured.
  54   DCHECK_EQ(monitor_fd_, fd);
  55   udev_device* dev = udev_monitor_receive_device(monitor_);
  56   if (!dev) {
  57     NOTREACHED();
  58     return;
  59   }
  60   callback_.Run(dev);
  61   udev_device_unref(dev);
  62 }
  63
  64 void UdevLinux::OnFileCanWriteWithoutBlocking(int fd) {
  65 }
  66
  67 }  // namespace content